Myocardial Infarction
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Pubmed
Journal: Lancet (London, England)
October/12/1993
Abstract

The effect of late thrombolysis in acute myocardial infarction (AMI)--ie, treatment beginning more than 6 h after the onset of symptoms--remains controversial. The Late Assessment of Thrombolytic Efficacy (LATE) study is a large randomised trial designed to resolve this question. 5711 patients with symptoms and electrocardiographic criteria consistent with AMI were randomised double-blind to intravenous alteplase (100 mg over 3 h) or matching placebo, between 6 and 24 h from symptom onset. Both groups received immediate oral aspirin and for later recruits intravenous heparin for 48 h was recommended. All patients were followed up for at least 6 months and 73% were followed up for 1 year. Intention-to-treat analysis of survival revealed a non-significant reduction in the alteplase group (397/2836 deaths) compared with placebo (444/2875). 35-day mortality was 8.86% and 10.31%, respectively, a relative reduction of 14.1% (95% CI 0-28.1%). Pre-specified survival analysis according to treatment within 12 h of symptom onset, however, showed a significant reduction in mortality in favour of alteplase: 35-day mortality was 8.90% versus 11.97% for placebo, a relative reduction of 25.6% (p = 0.0229, 95% CI 6.3-45.0%). Rates were 8.7% and 9.2%, respectively, for those treated at 12-24 h but subgroup analysis suggests that some patients may benefit even when treated after 12 h. Although treatment with alteplase resulted in an excess of haemorrhagic strokes, by 6 months the number of disabled survivors was the same in both treatment groups and other clinical events were observed with similar frequency in the two groups. We conclude that the time window for thrombolysis with alteplase should be extended to at least 12 h from symptom onset in patients with AMI.

Pubmed
Journal: Journal of the American College of Cardiology
January/24/2001
Abstract

OBJECTIVE

We sought to evaluate the prognostic impact of right ventricular (RV) myocardial involvement in patients with inferior myocardial infarction (MI).

BACKGROUND

There is uncertainty regarding the risk of major complications in patients with inferior MI complicated by RV myocardial involvement. Whether these complications are related to RV myocardial involvement itself or simply to the extent of infarction involving the left ventricle (LV) is also unknown.

METHODS

We examined the incidence of death and mechanical and electrical complications in patients with (n = 491) and without (n = 638) RV myocardial involvement and in patients with anterior MI (n = 971) in an analysis from the Collaborative Organization for RheothRx Evaluation (CORE) trial. Left ventricular infarct size was assessed by technetium-99m-sestamibi single-photon emission computed tomography and peak creatine kinase, and LV function was assessed by radionuclide angiography. We also performed a meta-analysis in which we pooled the results of our study with previous smaller studies addressing the same question.

RESULTS

Six-month mortality was 7.8% in inferior MI compared with 13.2% in anterior MI. Among patients with inferior MI, serious arrhythmias were significantly more common in patients with RV myocardial involvement who also had a trend toward higher mortality, pump failure and mechanical complications. However, this was not associated with a difference in LV infarct size or function. A meta-analysis of six studies (n = 1,198) confirmed that RV myocardial involvement was associated with an increased risk of death (odds ratio [OR] 3.2, 95% confidence interval [CI] 2.4 to 4.1), shock (OR 3.2, 95% CI 2.4 to 3.5), ventricular tachycardia or fibrillation (OR 2.7, 95% CI 2.1 to 3.5) and atrioventricular block (OR 3.4, 95% CI 2.7 to 4.2).

CONCLUSIONS

Patients with inferior MI who also have RV myocardial involvement are at increased risk of death, shock and arrhythmias. This increased risk is related to the presence of RV myocardial involvement itself rather than the extent of LV myocardial damage.

Pubmed
Journal: Journal of the American College of Cardiology
February/26/2007
Abstract

Dual antiplatelet therapy with aspirin and a thienopyridine has been shown to reduce cardiac events after coronary stenting. However, many patients and healthcare providers prematurely discontinue dual antiplatelet therapy, which greatly increases the risk of stent thrombosis, myocardial infarction, and death. This advisory stresses the importance of 12 months of dual antiplatelet therapy after placement of a drug-eluting stent and educating the patient and healthcare providers about hazards of premature discontinuation. It also recommends postponing elective surgery for 1 year, and if surgery cannot be deferred, considering the continuation of aspirin during the perioperative period in high-risk patients with drug-eluting stents.

Pubmed
Journal: Circulation research
May/30/2007
Abstract

Inflammatory responses after myocardial infarction profoundly impact tissue repair. Yet, efficient tools to serially and noninvasively assess cellular and molecular functions in postinfarct inflammation are lacking. Here we use multichannel fluorescent molecular tomography (FMT) for spatiotemporal resolution of phagocytic and proteolytic activities mediated by macrophages and neutrophils in murine infarcts. We performed FMT imaging to compare the course of efficient and impaired healing in wild-type and FXIII-/- mice, respectively. Mice subjected to coronary ligation received simultaneous injections with Prosense-680, an activatable fluorescence sensor reporting on cathepsin activity, and CLIO-VT750, a magneto-fluorescent nanoparticle for imaging of phagocyte recruitment. On FMT, Prosense-680 infarct signal was 19-fold higher than background (P<0.05). Protease activity was higher in the infarcted lateral wall than in the remote, uninjured septum on ex vivo fluorescence reflectance imaging (contrast to noise ratio 118+/-24). CLIO-VT750 FMT signal coregistered with contrast enhancement in the hypokinetic infarct on MRI. Microscopic fluorescence signal colocalized with immunoreactive staining for cathepsin, macrophages and neutrophils. Flow cytometry of digested infarcts revealed monocytes/macrophages and neutrophils as the source of the fluorescence signal. Phagocytic activity peaked on day 6, and proteolytic activity peaked on day 4 after myocardial infarction. FMT detected impaired recruitment of phagocytes and protease activity in FXIII-/- mice (P<0.05). FMT is a promising noninvasive molecular imaging approach to characterize infarct healing. Spectrally resolved imaging agents allow for simultaneous assesment of key processes of in vivo cellular functions. Specifically, we show that in vivo FMT detects impaired healing in FXIII-/- mice.

Pubmed
Journal: Circulation research
July/31/1988
Abstract

Excitation in the epicardial border zone of 3-5-day-old canine infarcts was mapped with an array of 192 bipolar electrodes during sustained ventricular tachycardia. Reentrant circuits were found in which activation occurred around long lines of apparent conduction block based on the criterion that excitation on opposite sides of the lines occurred with marked disparity in time. When the lines of apparent block were functional (i.e., occurred only during tachycardia and not during sinus rhythm or ventricular pacing) they were oriented parallel to the long axis of epicardial muscle fiber bundles. Isochrones distal to the lines were oriented parallel to them because widely separate sites within these isochrones were activated nearly simultaneously. This suggested that excitation not only occurred around the lines of block but also slowly across them. This slow activation occurred transverse to the long axis of the myocardial fibers and therefore might result because of the anisotropic tissue properties. To test this hypothesis, the epicardial border zone was stimulated during sinus rhythm through electrodes around its margin and at the center of the recording array. Activation transverse to the myocardial fibers in regions where lines of block occurred during tachycardia was slow, whereas it was rapid parallel to fibers' orientation. During tachycardia electrograms along the lines of apparent block had long durations and were fractionated, a characteristic that can also result from activation transverse to the myocardial fiber long axis. Therefore, we propose that the parallel orientation of the muscle bundles in the epicardial border zone is an important cause of ventricular tachycardia because activation transverse to myocardial fibers is sufficiently slow to permit the occurrence of reentry.

Pubmed
Journal: Circulation
December/3/2006
Abstract

BACKGROUND

It has been suggested that the survival benefit associated with primary percutaneous coronary intervention (PPCI) in ST-segment elevation myocardial infarction may be attenuated if door-to-balloon (DB) time is delayed by >1 hour beyond door-to-needle (DN) times for fibrinolytic therapy. Whereas DB times are rapid in randomized trials, they are often prolonged in routine practice. We hypothesized that in clinical practice, longer DB-DN times would be associated with higher mortality rates and reduced PPCI survival advantage. We also hypothesized that in addition to PPCI delays, patient risk factors would significantly modulate the relative survival advantage of PPCI over fibrinolysis.

RESULTS

DB-DN times were calculated by subtracting median DN time from median DB time at a hospital using data from 192,509 patients at 645 National Registry of Myocardial Infarction hospitals. Hierarchical models that adjusted simultaneously for both patient-level risk factors and hospital-level covariates were used to evaluate the relationship between PCI-related delay, patient risk factors, and in-hospital mortality. Longer DB-DN times were associated with increased mortality (P<0.0001). The DB-DN time at which mortality rates with PPCI were no better than that of fibrinolysis varied considerably depending on patient age, symptom duration, and infarct location.

CONCLUSIONS

As DB-DN times increase, the mortality advantage of PPCI over fibrinolysis declines, and this advantage varies considerably depending on patient characteristics. As indicated in the American College of Cardiology/American Heart Association guidelines, both the hospital-based PPCI-related delay (DB-DN time) and patient characteristics should be considered when a reperfusion strategy is selected.

Pubmed
Journal: Nature medicine
February/1/2012
Abstract

Excessive activation of the β-adrenergic, angiotensin II (Ang II) and aldosterone signaling pathways promotes mortality after myocardial infarction, and antagonists targeting these pathways are core therapies for treating this condition. Catecholamines and Ang II activate the multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), the inhibition of which prevents isoproterenol-mediated and Ang II-mediated cardiomyopathy. Here we show that aldosterone exerts direct toxic actions on myocardium by oxidative activation of CaMKII, causing cardiac rupture and increased mortality in mice after myocardial infarction. Aldosterone induces CaMKII oxidation by recruiting NADPH oxidase, and this oxidized and activated CaMKII promotes matrix metalloproteinase 9 (MMP9) expression in cardiomyocytes. Myocardial CaMKII inhibition, overexpression of methionine sulfoxide reductase A (an enzyme that reduces oxidized CaMKII) or NADPH oxidase deficiency prevented aldosterone-enhanced cardiac rupture after myocardial infarction. These findings show that oxidized myocardial CaMKII mediates the cardiotoxic effects of aldosterone on the cardiac matrix and establish CaMKII as a nodal signal for the neurohumoral pathways associated with poor outcomes after myocardial infarction.

Pubmed
Journal: Health affairs (Project Hope)
May/7/2007
Abstract

To complement the current process measures for treating patients with heart attacks and with heart failure, which target gaps in quality but do not capture patient outcomes, the Centers for Medicare and Medicaid Services (CMS) has proposed the public reporting of hospital-level thirty-day mortality for these conditions in 2007. We present the case for including measurements of outcomes in the assessment of hospital performance, focusing on the care of patients with heart attacks and with heart failure. Recent developments in the methodology and standards for outcomes measurement have laid the groundwork for incorporating outcomes into performance monitoring efforts for these conditions.

Pubmed
Journal: JAMA
November/27/2005
Abstract

BACKGROUND

The chest pain history, physical examination, determination of coronary artery disease (CAD) risk factors, and the initial electrocardiogram compose the information immediately available to clinicians to help determine the probability of acute myocardial infarction (AMI) or acute coronary syndrome (ACS) in patients with chest pain. However, conflicting data exist about the usefulness of the chest pain history and which components are most useful.

OBJECTIVE

To identify the elements of the chest pain history that may be most helpful to the clinician in identifying ACS in patients presenting with chest pain.

METHODS

MEDLINE and Ovid were searched from 1970 to September 2005 by using specific key words and Medical Subject Heading terms. Reference lists of these articles and current cardiology textbooks were also consulted.

RESULTS

Certain chest pain characteristics decrease the likelihood of ACS or AMI, namely, pain that is stabbing, pleuritic, positional, or reproducible by palpation (likelihood ratios [LRs] 0.2-0.3). Conversely, chest pain that radiates to one shoulder or both shoulders or arms or is precipitated by exertion is associated with LRs (2.3-4.7) that increase the likelihood of ACS. The chest pain history itself has not proven to be a powerful enough predictive tool to obviate the need for at least some diagnostic testing. Combinations of elements of the chest pain history with other initially available information, such as a history of CAD, have identified certain groups that may be safe for discharge without further evaluation, but further study is needed before such a recommendation can be considered reasonable.

CONCLUSIONS

Although certain elements of the chest pain history are associated with increased or decreased likelihoods of a diagnosis of ACS or AMI, none of them alone or in combination identify a group of patients that can be safely discharged without further diagnostic testing.

Pubmed
Journal: American journal of epidemiology
June/7/1994
Abstract

Most studies are unable to follow nonrespondents prospectively to determine whether their disease rates are comparable with those of the respondents. The authors followed respondents and nonrespondents to a mailed questionnaire, sent to a random sample of Iowa women aged 55-69 years in 1986 (total sample, 98,029; 43% response), to characterize 5-year mortality rates for myocardial infarction and all causes, and attack rates for breast, endometrial, colon, lung, and all-site cancers. Compared with respondents, nonrespondents had higher myocardial infarction (1.47 vs. 0.93 per 1,000 person-years) and all-cause (12.32 vs. 7.89 per 1,000 person-years) mortality. They also had substantially higher attack rates for lung cancer (1.45 vs. 1.10 per 1,000 person-years), and slightly higher attack rates for all-site cancer (11.86 vs. 10.89 per 1,000 person-years). The associations of reported body mass index (weight/height2) with the study endpoints were generally similar among respondents and the total eligible sample, except for a more pronounced U-shaped total mortality association for the nonrespondents. Thus, although the occurrence of several diseases, especially those related to smoking, differed among respondents and nonrespondents, the association of body mass index with cancer occurrence was not appreciably affected by nonresponse bias.

Pubmed
Journal: Diabetes
May/19/2004
Abstract

The object of this study was to establish the association between the metabolic syndrome and oxidized LDL (oxLDL) and to determine the risk for coronary heart disease (CHD) in relation to the metabolic syndrome and levels of oxLDL. OxLDL was measured in plasma from 3,033 elderly participants in the Health, Aging, and Body Composition study. The metabolic syndrome was defined according to criteria established in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. We observed that the metabolic syndrome was associated with higher levels of oxLDL due to a higher fraction of oxLDL, not to higher levels of LDL cholesterol. Individuals with the metabolic syndrome had twice the odds of having high oxLDL (>1.90 mg/dl) compared with those not having the metabolic syndrome, after adjusting for age, sex, ethnicity, smoking status, and LDL cholesterol. Among those participants who had the metabolic syndrome at study entry, incidence rates of future CHD events were 1.6-fold higher, after adjusting for age, sex, ethnicity, and smoking status. OxLDL was not an independent predictor of total CHD risk. However, those with high oxLDL showed a greater disposition to myocardial infarction (relative risk 2.25, 95% confidence interval 1.22-4.15). We concluded that the metabolic syndrome, a risk factor for CHD, is associated with higher levels of circulating oxLDL that are associated with a greater disposition to atherothrombotic coronary disease.

Pubmed
Journal: Circulation
February/12/2003
Abstract

BACKGROUND

Managing chest pain in the emergency department remains a challenge with current diagnostic strategies. We hypothesized that cardiac MRI could accurately identify patients with possible or probable acute coronary syndrome.

RESULTS

The diagnostic performance of MRI was evaluated in a prospective study of 161 consecutive patients. Enrollment required 30 minutes of chest pain compatible with myocardial ischemia but an ECG not diagnostic of acute myocardial infarction. MRI was performed at rest within 12 hours of presentation and included perfusion, left ventricular function, and gadolinium-enhanced myocardial infarction detection. MRI was interpreted qualitatively but also analyzed quantitatively. The sensitivity and specificity, respectively, for detecting acute coronary syndrome were 84% and 85% by MRI, 80% and 61% by an abnormal ECG, 16% and 95% for strict ECG criteria for ischemia (ST depression or T-wave inversion), 40% and 97% for peak troponin-I, and 48% and 85% for a TIMI risk score > or =3. The MRI was more sensitive than strict ECG criteria for ischemia (P<0.001), peak troponin-I (P<0.001), and the TIMI risk score (P=0.004), and MRI was more specific than an abnormal ECG (P<0.001). Multivariate logistic regression analysis showed MRI was the strongest predictor of acute coronary syndrome and added diagnostic value over clinical parameters (P<0.001).

CONCLUSIONS

Resting cardiac MRI exhibited diagnostic operating characteristics suitable for triage of patients with chest pain in the emergency department. Performed urgently to evaluate chest pain, MRI accurately detected a high fraction of patients with acute coronary syndrome, including patients with enzyme-negative unstable angina.

Pubmed
Journal: British journal of anaesthesia
January/5/2000
Abstract

Magnesium has an established role in obstetrics and an evolving role in other clinical areas, in particular cardiology. Many of the effects involving magnesium are still a matter of controversy. Over the next decade, it is likely that improvements in the measurement of magnesium, a clearer understanding of the mechanisms of its actions and further results of clinical studies will help to elucidate its role, both in terms of treating deficiency and as a pharmacological agent.

Pubmed
Journal: Circulation
July/26/1999
Abstract

BACKGROUND

The role of a cluster of risk factors characteristic for the insulin resistance syndrome as a predictor for coronary heart disease (CHD) has not been studied previously.

RESULTS

Clustering of cardiovascular risk factors was analyzed by factor analysis to investigate whether these clusters (factors) predict CHD events (CHD death or nonfatal myocardial infarction) in a nondiabetic population of 1069 subjects 65 to 74 years old from eastern Finland followed up for 7 years. There were 151 CHD events (92 for men, 59 for women) during the follow-up period. In men, factor 1 (the insulin resistance factor, which reflected primarily body mass index, waist-to-hip ratio, triglycerides, fasting plasma glucose, and insulin) (hazards ratio [HR] with 95% CI, 1.33, CI 1.08, 1.65, P=0.008), factor 2 (alcohol consumption, high HDL cholesterol, low triglycerides) (HR 0.78, CI 0.63, 0.96, P=0.020), factor 3 (age, systolic blood pressure, urinary albumin/creatinine ratio, left ventricular hypertrophy) (HR 1.52, CI 1.26, 1.83, P<0.001), and factor 4 (high total cholesterol and triglycerides) (HR 1.42, CI 1. 15, 1.77, P=0.002) predicted CHD events in multivariate Cox regression analysis. In women, the insulin resistance factor did not predict CHD events (HR 1.06, CI 0.82, 1.36), but factor 2 (previous stroke, low HDL cholesterol and high triglycerides) (HR 1.34, CI 1. 06, 1.69, P=0.014) and factor 3 (age, systolic blood pressure, urinary albumin/creatinine ratio, left ventricular hypertrophy) (HR 1.44, CI 1.15, 1.82, P=0.002) predicted CHD events.

CONCLUSIONS

Our study supports the notion that the insulin resistance syndrome is a risk factor for CHD in elderly men.

Pubmed
Journal: Arteriosclerosis (Dallas, Tex.)
June/20/1988
Abstract

The relation between high density lipoprotein cholesterol (HDL-C) and the development of myocardial infarction was examined in 2425 subjects, aged 50 to 79 years, who were enrolled in the Framingham Study from 1969 to 1971. After 12 years of follow-up, men in the bottom three quartiles of HDL-C (less than or equal to 52 mg/dl) experienced a 60% to 70% excess of myocardial infarction as compared to men whose HDL-C levels were higher (p less than 0.05). The effect of HDL-C was especially strong in women. In separate comparisons to the 4th quartile of HDL-C (greater than or equal to 67 mg/dl), the risk of myocardial infarction increased from a fourfold excess in the adjacent 3rd quartile (56 to 66 mg/dl, p less than 0.01) to a nearly sixfold excess in the 1st quartile (less than or equal to 46 mg/dl, p less than 0.001). These results persisted after adjusting for age and other risk factors. In addition, a significant effect of HDL-C remained in subjects who had the lowest concentrations of total cholesterol (less than or equal to 192 mg/dl in men and 211 mg/dl in women) in which 29% had levels of HDL-C (less than or equal to 36 mg/dl in men and 46 mg/dl in women) that were associated with a marked elevation in the incidence of myocardial infarction. We conclude that screening for total cholesterol alone in men and women aged 50 and older may not adequately identify the coronary candidate.(ABSTRACT TRUNCATED AT 250 WORDS)

Pubmed
Journal: Journal of the American College of Cardiology
May/18/2005
Abstract

OBJECTIVE

We sought to assess prospectively whether patients with normal coronary angiograms but with impaired myocardial blood flow (MBF) increases to cold pressor testing (CPT) are at increased risk for cardiovascular events.

BACKGROUND

Invasive angiographic assessments of coronary vasomotor function have demonstrated an impairment of endothelium-related coronary flow increases to independently predict future cardiovascular events. It is unknown whether noninvasive positron emission tomography (PET)-measured MBF alterations to sympathetic stimulation with CPT are associated with the risk of developing cardiovascular events.

METHODS

A total of 72 patients (44 men, 28 women, age 58 +/- 8 years) referred for diagnostic cardiac catheterization were studied. Myocardial blood flow was measured in absolute units with (13)N-ammonia using PET, at baseline and during CPT in each patient. Cardiovascular events (cardiovascular death, acute coronary syndrome, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, ischemic stroke, or peripheral revascularization) were assessed as clinical outcome parameters over a mean follow-up period of 66 +/- 8 months. Patients were assigned to three groups: group 1, patients with >/=40% increase in MBF (%DeltaMBF), n = 22; group 2, patients with >0 and <40% increases in MBF, n = 32; and group 3, patients with decreases in MBF (</=0%), n = 18.

RESULTS

During follow-up, one of the group 1 patients developed a cerebral stroke. In group 2, 15 cardiovascular events occurred in 9 patients and in group 3, 7 patients experienced 9 cardiovascular events (p </= 0.0001, univariate by log-rank test). Impaired MBF increases in group 2 and group 3 were associated with a significantly higher incidence of cardiovascular events by Kaplan-Meier analysis (p = 0.033, log-rank test). After adjusting for known coronary risk factors, MBF responses to CPT revealed a nonsignificant trend to be independently associated with a higher incidence for cardiovascular events (p = 0.065, multivariate by Cox regression model).

CONCLUSIONS

Noninvasive PET-measured impaired MBF increases to sympathetic stimulation are associated with the risk of developing cardiovascular events.

Pubmed
Journal: Circulation
August/12/1998
Abstract

BACKGROUND

A large transmural myocardial infarction may initiate structural and geometric changes in the left ventricle that are commonly referred to as remodeling. Progressive, adverse remodeling of the myocardium may lead to ventricular dilatation and congestive heart failure. Recent studies have highlighted the effects of some cytokines on immune-mediated myocyte injury, postischemic myocardial inflammation, and cardiac function. However, studies of the involvement of cytokines in remodeling of the heart are few.

RESULTS

In a rat model of myocardial infarction, progressive dilatation of the left ventricular cavity and lack of appropriate hypertrophy of the surviving myocardium were confirmed by transthoracic echocardiography. The relative expression of mRNA for tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 in the infarcted and noninfarcted myocardium of these rats, as well as in a group of sham-operated animals, was assessed by the technique of quantitative polymerase chain reaction amplification. In the infarcted region, TNF-alpha, IL-1beta, and IL-6 gene expression peaked at 1 week after infarction and decreased rapidly thereafter. In contrast, at 20 weeks after infarction, the gene expression levels of these cytokines remained significantly higher in the noninfarcted than in the infarcted zone or in the myocardium of sham-operated animals. Furthermore, the levels of these cytokines in the noninfarcted region correlated with the left ventricular end-diastolic diameter measured at 8 and 20 weeks after infarction. Among these cytokines, IL-1beta expression was highest, and its level correlated well with collagen deposition in the noninfarcted myocardium at 8 and 20 weeks after surgery. At 20 weeks after infarction, immunohistochemical analysis revealed the presence of IL-1beta in macrophages, endothelial cells, and vascular smooth muscle cells in the noninfarcted region, whereas no such immunoreactivity was found in the myocardium of sham-operated animals.

CONCLUSIONS

These findings suggest the possible involvement of cytokines during the remodeling process of the noninfarcted left ventricular myocardium.

Pubmed
Journal: Cardiovascular drugs and therapy
January/8/2008
Abstract

BACKGROUND

Necrostatin-1 (Nec-1), a small tryptophan-based molecule, was recently reported to protect the cerebral cortex against ischemia-reperfusion (I/R) injury. We investigated the actions of Nec-1 and its so-called inactive analog, Nec-1i, in the setting of myocardial I/R injury.

METHODS

The actions of Nec-1 and Nec-1i were examined in cultured C2C12 and H9c2 myocytes, cardiomyocytes isolated from male Sprague-Dawley rats, Langendorff isolated perfused C57Bl/6J mouse hearts and an in vivo open-chest C57Bl/6J mouse heart model.

RESULTS

Nec-1 at 30 microM and 100 microM (but not 100 microM Nec-1i) reduced peroxide-induced cell death in C2C12 cells from 51.2 +/- 1.1% (control) to 26.3 +/- 2.9% (p < 0.01 vs control) and 17.8 +/- 0.9% (p < 0.001), respectively. With H9c2 cells cell death was also reduced from 73.0 +/- 0.4% (control) to 56.7 +/- 0% (30 microM Nec-1, p < 0.05) and 45.4 +/- 3.3% (100 microM Nec-1, p < 0.01). In the isolated perfused heart Nec-1 (30 microM) reduced infarct size (calculated as a percentage of the risk area) from 48.0 +/- 2.0% (control) to 32.1 +/- 5.4% (p < 0.05). Nec-1i (30 microM) also reduced infarct size (32.9 +/- 5.1%, p < 0.05). In anesthetized C57Bl/6J mice Nec-1 (1.65 mg/kg), given intraperitoneally to coincide with reperfusion following left anterior descending artery ligation (30 min), also reduced infarct size from 45.3 +/- 5.1% (control) to 26.6 +/- 4.0% (p < 0.05), whilst Nec-1i (1.74 mg/kg) was ineffective (37.8 +/- 6.0%). Stimulus-induced opening of the mitochondrial permeability transition pore (MPTP) in rat cardiomyocytes, as reflected by the time until mitochondrial depolarisation, was unaffected by Nec-1 or Nec-1i at 30 muM but increased at 100 muM i.e. 91% (p < 0.05 vs control) and 152% (p < 0.001) for Nec-1 and Nec-1i, respectively.

CONCLUSIONS

This is the first study to demonstrate that necrostatins inhibit myocardial cell death and reduce infarct size, possibly via a mechanism independent of the MPTP.

Pubmed
Journal: The New England journal of medicine
September/18/2013
Abstract

BACKGROUND

Although P2Y12 antagonists are effective in patients with non-ST-segment elevation (NSTE) acute coronary syndromes, the effect of the timing of administration--before or after coronary angiography--is not known. We evaluated the effect of administering the P2Y12 antagonist prasugrel at the time of diagnosis versus administering it after the coronary angiography if percutaneous coronary intervention (PCI) was indicated.

METHODS

We enrolled 4033 patients with NSTE acute coronary syndromes and a positive troponin level who were scheduled to undergo coronary angiography within 2 to 48 hours after randomization. Patients were randomly assigned to receive prasugrel (a 30-mg loading dose) before the angiography (pretreatment group) or placebo (control group). When PCI was indicated, an additional 30 mg of prasugrel was given in the pretreatment group at the time of PCI and 60 mg of prasugrel was given in the control group.

RESULTS

The rate of the primary efficacy end point, a composite of death from cardiovascular causes, myocardial infarction, stroke, urgent revascularization, or glycoprotein IIb/IIIa inhibitor rescue therapy (glycoprotein IIb/IIIa bailout) through day 7, did not differ significantly between the two groups (hazard ratio with pretreatment, 1.02; 95% confidence interval [CI], 0.84 to 1.25; P=0.81). The rate of the key safety end point of all Thrombolysis in Myocardial Infarction (TIMI) major bleeding episodes, whether related or not related to coronary-artery bypass grafting (CABG), through day 7 was increased with pretreatment (hazard ratio, 1.90; 95% CI, 1.19 to 3.02; P=0.006). The rates of TIMI major bleeding and life-threatening bleeding not related to CABG were increased by a factor of 3 and 6, respectively. Pretreatment did not reduce the rate of the primary outcome among patients undergoing PCI (69% of the patients) but increased the rate of TIMI major bleeding at 7 days. All the results were confirmed at 30 days and in prespecified subgroups.

CONCLUSIONS

Among patients with NSTE acute coronary syndromes who were scheduled to undergo catheterization, pretreatment with prasugrel did not reduce the rate of major ischemic events up to 30 days but increased the rate of major bleeding complications. (Funded by Daiichi Sankyo and Eli Lilly; ACCOAST ClinicalTrials.gov number, NCT01015287.).

Pubmed
Journal: Basic & clinical pharmacology & toxicology
November/28/2006
Abstract

Whether non-aspirin non-steroidal antiinflammatory drugs (NSAIDs) affect the risk of myocardial infarction is unclear. Also, it is unknown whether the effect varies by individual NSAIDs. To summarize the evidence from published observational studies on the risk of myocardial infarction associated with both traditional NSAIDs (tNSAIDs) and selective inhibitors of cyclooxygenase-2 (Coxibs), the authors conducted a systematic review of cohort and case-control studies on NSAIDs and myocardial infarction published between 2000 and 2005. Sixteen original studies were selected according to predefined criteria. Two researchers independently extracted the data on individual study characteristics and results. The authors calculated pooled relative risk (RR) estimates of myocardial infarction for specific NSAIDs compared with no NSAID use, tested the heterogeneity of effects, and evaluated potential reasons for heterogeneity. The pooled RR of myocardial infarction was 0.98 (95% confidence interval (CI): 0.92-1.05) for naproxen, 1.07 (95% CI: 1.02-1.12) for ibuprofen, 1.44 (95% CI: 1.32-1.56) for diclofenac, 0.96 (95% CI: 0.90-1.02) for celecoxib, and 1.26 (95% CI: 1.17-1.36) for rofecoxib (all doses). The pooled RR for rofecoxib at doses >25 mg/day was 1.78 (95% CI: 1.36-2.34), and 1.18 (95% CI: 1.07-1.31) for doses < or =25 mg/day. The RR associated with naproxen was 0.83 (95% CI: 0.72-0.90) among non-users of low-dose aspirin. The RR associated with rofecoxib (all doses) was 1.39 (95% CI: 1.25-1.54) among subjects without a history of myocardial infarction. The risk of myocardial infarction varies with individual NSAIDs. An increased risk was observed for diclofenac and rofecoxib, the latter one with a clear dose-response trend. There was a suggestion of a small increased risk with ibuprofen. Also, data suggest a small reduced risk for naproxen present only in non-users of aspirin, mainly people free of clinically apparent vascular disease.

Pubmed
Journal: Circulation research
April/24/2005
Abstract

Bone marrow mononuclear cells (BMCs) from 20 patients with extensive reperfused myocardial infarction (MI) were used to assess their myocardial regenerative capability "in vitro" and their effect on postinfarction left ventricular (LV) remodeling. Human BMCs were labeled, seeded on top of cryoinjured mice heart slices, and cultured. BMCs showed tropism for and ability to graft into the damaged mouse cardiac tissue and, after 1 week, acquired a cardiomyocyte phenotype and expressed cardiac proteins, including connexin43. In the clinical trial, autologous BMCs (78+/-41x10(6) per patient) were intracoronarily transplanted 13.5+/-5.5 days after MI. There were no adverse effects on microvascular function or myocardial injury. No major cardiac events occurred up to 11+/-5 months. At 6 months, magnetic resonance showed a decrease in the end-systolic volume, improvement of regional and global LV function, and increased thickness of the infarcted wall, whereas coronary restenosis was only 15%. No changes were found in a nonrandomized contemporary control group. Thus, BMCs are capable of nesting into the damaged myocardium and acquire a cardiac cell phenotype in vitro as well as safely benefiting ventricular remodeling in vivo. Large-scale randomized trials are needed now to assess the clinical efficacy of this treatment.

Pubmed
Journal: Circulation
March/12/2012
Abstract

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after implantation of drug-eluting coronary stents remains undetermined. We aimed to test whether 6-month DAPT would be noninferior to 12-month DAPT after implantation of drug-eluting stents.

RESULTS

We randomly assigned 1443 patients undergoing implantation of drug-eluting stents to receive 6- or 12-month DAPT (in a 1:1 ratio). The primary end point was a target vessel failure, defined as the composite of cardiac death, myocardial infarction, or ischemia-driven target vessel revascularization at 12 months. Rates of target vessel failure at 12 months were 4.8% in the 6-month DAPT group and 4.3% in the 12-month DAPT group (the upper limit of 1-sided 95% confidence interval, 2.4%; P=0.001 for noninferiority with a predefined noninferiority margin of 4.0%). Although stent thrombosis tended to occur more frequently in the 6-month DAPT group than in the 12-month group (0.9% versus 0.1%; hazard ratio, 6.02; 95% confidence interval, 0.72-49.96; P=0.10), the risk of death or myocardial infarction did not differ in the 2 groups (2.4% versus 1.9%; hazard ratio, 1.21; 95% confidence interval, 0.60-2.47; P=0.58). In the prespecified subgroup analysis, target vessel failure occurred more frequently in the 6-month DAPT group than in the 12-month group (hazard ratio, 3.16; 95% confidence interval, 1.42-7.03; P=0.005) among diabetic patients.

CONCLUSIONS

Six-month DAPT did not increase the risk of target vessel failure at 12 months after implantation of drug-eluting stents compared with 12-month DAPT. However, the noninferiority margin was wide, and the study was underpowered for death or myocardial infarction. Our results need to be confirmed in larger trials.

BACKGROUND

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00698607.

Pubmed
Journal: Annals of internal medicine
August/30/2005
Abstract

BACKGROUND

After the acute coronary syndrome, adding warfarin to standard aspirin therapy decreases myocardial infarction and stroke but increases major bleeding.

OBJECTIVE

To quantify the risks and benefits of warfarin therapy after the acute coronary syndrome.

METHODS

MEDLINE from 1990 to October 2004. Additional data were obtained from study authors. Clinical risk factors were used to classify hypothetical patients into cardiovascular and bleeding risk groups on the basis of published data.

METHODS

Randomized trials comparing intensive warfarin therapy (international normalized ratio > 2.0) plus aspirin with aspirin alone after the acute coronary syndrome.

METHODS

Two reviewers independently selected studies and extracted data on study design; quality; and clinical outcomes, including myocardial infarction, stroke, revascularization, death, and major and minor bleeding. Rate ratios for outcomes were calculated and pooled by using the method of DerSimonian and Laird.

RESULTS

Ten trials involving a total of 5938 patients (11,334 patient-years) met the study criteria. Compared with aspirin alone, warfarin plus aspirin was associated with a decrease in the annual rate of myocardial infarction (0.022 vs. 0.041; rate ratio, 0.56 [95% CI, 0.46 to 0.69]), ischemic stroke (0.004 vs. 0.008; rate ratio, 0.46 [CI, 0.27 to 0.77]), and revascularization (0.115 vs. 0.135; rate ratio, 0.80 [CI, 0.67 to 0.95]). Warfarin was associated with an increase in major bleeding (0.015 vs. 0.006; rate ratio, 2.5 [CI, 1.7 to 3.7]). Mortality did not differ.

CONCLUSIONS

Two large studies provided most of the data. Studies did not include coronary stenting, and results should not be applied to patients with stents. Relative risk reductions may not be consistent across risk groups.

CONCLUSIONS

For patients with the acute coronary syndrome who are at low or intermediate risk for bleeding, the cardiovascular benefits of warfarin outweigh the bleeding risks.

Pubmed
Journal: The Journal of thoracic and cardiovascular surgery
May/31/2004
Abstract

OBJECTIVE

It is thought that adult human mesenchymal stem cells do not induce immunoreactivity even to xenografts. We wanted to study whether adult human mesenchymal stem cells survive and engraft in experimentally induced ischemic rat myocardium.

METHODS

Bone marrow-derived adult human mesenchymal stem cells (2.5 x 10(6)) were injected into the myocardium of 4 Sprague-Dawley rats. One week after injection, peripheral blood rat lymphocytes were added to adult human mesenchymal stem cells in a mixed lymphocyte reaction. Furthermore, an infarction was created by left anterior descending artery ligation of 8 Sprague-Dawley rats, 4 of which were immunosuppressed with tacrolimus (0.1 mg/kg/d) and 4 RNU athymic rats. One week after left anterior descending artery ligation, 2.5 to 3.5 x 10(6) adult human mesenchymal stem cells were injected around the infarcted area. The adult human mesenchymal stem cells were identified with fluorescence in situ hybridization technique and myocardial antigens by immunohistochemistry. The immune response was studied by hematoxylin and eosin staining and by antibodies directed toward macrophages.

RESULTS

Significant rat lymphocyte proliferation was observed when adult human mesenchymal stem cells were added to peripheral blood from Sprague-Dawley rats previously exposed to adult human mesenchymal stem cells. No reactivity was seen in lymphocytes from untreated Sprague-Dawley rats and athymic rats. Adult human mesenchymal stem cells could only be identified in the myocardium of athymic rats. Further, in normal Sprague-Dawley rats, there was a significant myocardial infiltration of round cells, mostly macrophages, in the area of injection of adult human mesenchymal stem cells. In RNU rats, this reaction was less intense.

CONCLUSIONS

Adult human mesenchymal stem cells did not induce xenoreactivity in vitro in previously unexposed immunocompetent Sprague-Dawley rats. However, although mesenchymal stem cells are transplantable across allogeneic barriers, transplant rejection can occur in a xenogenic model. When transplanted into an immunoincompetent host, adult human mesenchymal stem cells showed persistent engraftment.

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