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Background: Sudden death (SD) is a frequent catastrophic complication in patients after myocardial infarction. Circumstances of SD may affect strategies for prevention., Methods and Results: We reviewed source documentation for 1067 patients who had SD in the Valsartan in Acute Myocardial Infarction Trial (VALIANT) trial. We determined the circumstances of these events and assessed long-term mortality in patients who were resuscitated. Location of the SD event was available in 978 of 1067 patients, with 226 events occurring within the first 40 days. Although SD was more likely to occur at home (645 of 978, 66%) than in hospital (204 of 978, 21%), the proportion of in-hospital events was higher early on (99 of 226, 44%). Home events were less likely to be witnessed regardless of time frame. Preceding activity was known for 42% of patients with home arrest; of these, 52% were determined to be asleep at time of event, and these deaths were more likely to be unwitnessed. A majority of patients for whom initial ECG rhythm was reported had ventricular tachycardia/ventricular fibrillation (189 of 283, 67%). Of the 155 patients successfully resuscitated, 24% subsequently received an implantable cardioverter-defibrillator. Nineteen percent of those who received an implantable cardioverter-defibrillator subsequently died compared with 49% of patients who did not receive an implantable cardioverter-defibrillator (hazard ratio, 0.36; 95% confidence interval, 0.14 to 0.93; P=0.04)., Conclusions: A high proportion of SD events after high-risk myocardial infarction occurred at home, but in-hospital events were more common early on. Patients who were asleep were more likely to have unwitnessed arrests. Alternative strategies for the prevention of SD in patients who are not candidates for implantable cardioverter-defibrillator will need to take into account the circumstances of SD events.

Background: The frequency of sudden unexpected death is highest in the early post-myocardial infarction (MI) period; nevertheless, 2 recent trials showed no improvement in mortality with early placement of an implantable cardioverter-defibrillator after MI., Methods and Results: To better understand the pathophysiological events that lead to sudden death after MI, we assessed autopsy records in a series of cases classified as sudden death events in patients from the VALsartan In Acute myocardial infarctioN Trial (VALIANT). Autopsy records were available in 398 cases (14% of deaths). We determined that 105 patients had clinical circumstances consistent with sudden death. On the basis of the autopsy findings, we assessed the probable cause of sudden death and evaluated how these causes varied with time after MI. Of 105 deaths considered sudden on clinical grounds, autopsy suggested the following causes: 3 index MIs in the first 7 days (2.9%); 28 recurrent MIs (26.6%); 13 cardiac ruptures (12.4%); 4 pump failures (3.8%); 2 other cardiovascular causes (stroke or pulmonary embolism; 1.9%); and 1 noncardiovascular cause (1%). Fifty-four cases (51.4%) had no acute specific autopsy evidence other than the index MI and were thus presumed arrhythmic. The percentage of sudden death due to recurrent MI or rupture was highest in the first month after the index MI. By contrast, after 3 months, the percentage of presumed arrhythmic death was higher than recurrent MI or rupture (chi(2)=23.3, P<0.0001)., Conclusions: Recurrent MI or cardiac rupture accounts for a high proportion of sudden death in the early period after acute MI, whereas arrhythmic death may be more likely subsequently. These findings may help explain the lack of benefit of early implantable cardioverter-defibrillator therapy.

Background: Mechanical dyssynchrony is considered an independent predictor for adverse cardiovascular outcomes in patients with heart failure. However, its importance as a risk factor after myocardial infarction is not well defined., Methods and Results: We examined the influence of mechanical dyssynchrony on outcome in patients with left ventricular dysfunction, heart failure, or both after myocardial infarction who were enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) echocardiography study. B-mode speckle tracking with velocity vector imaging was used to assess ventricular synchrony in 381 patients who had image quality sufficient for analysis. Time to regional peak velocity and time to strain rate were measured among 12 left ventricular segments from the apical 4- and 2- chamber views, and the SDs between all 12 segments were used as a measure of dyssynchrony. The relationships between the SD of time to regional peak velocity and strain rate and clinical outcome of death or heart failure were assessed. In a multivariate Cox model adjusted for clinical and echocardiographic variables, the SD of time to peak velocity (hazard ratio per 10 ms, 1.10; 95% confidence interval, 1.02 to 1.18; P=0.010) and the SD of time to strain rate (hazard ratio per 10 ms, 1.16; 95% confidence interval, 1.06 to 1.27; P=0.001) were independent predictors of death or heart failure., Conclusions: Left ventricular dyssynchrony is independently associated with increased risk of death or heart failure after myocardial infarction, suggesting that contractile pattern may play a role in post-myocardial infarction prognosis.