Pathogenesis of Sudden Unexpected Death in a Clinical Trial of Patients With Myocardial Infarction and Left Ventricular Dysfunction, Heart Failure, or Both
The frequency of sudden unexpected death is highest in the early post–myocardial infarction (MI) period; nevertheless, 2 recent large scale trials showed no improvement in mortality with early placement of an implantable cardioverter-defibrillator after MI.
This trial was recently published in Circulation journal and aimed to better understand the pathophysiological events that lead to sudden death after MI. The authors 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). They determined that 105 patients had clinical circumstances consistent with sudden death. On the basis of the autopsy findings, they 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 (
2=23.3, P<0.0001).
2=23.3, P<0.0001).From the above interesting findings, the authors concluded that 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.
REFERENCE:
Anne-Catherine Pouleur MD, PhD, Ebrahim Barkoudah MD, Hajime Uno PhD, Hicham Skali MD, MSc, Peter V. Finn MD, Steven L. Zelenkofske DO, Yuri N. Belenkov MD, PhD, Viacheslav Mareev MD, Eric J. Velazquez MD, Jean L. Rouleau MD, Aldo P. Maggioni MD, Lars Køber MD, Robert M. Califf MD, John J.V. McMurray MD, Marc A. Pfeffer MD, PhD, Scott D. Solomon MD*, for the VALIANT Investigators. Pathogenesis of Sudden Unexpected Death in a Clinical Trial of Patients With Myocardial Infarction and Left Ventricular Dysfunction, Heart Failure, or Both. Circulation. 2010;122:597-602.
