Pathogenesis of sudden unexpected death in a clinical trial of patients with myocardial infarction and left ventricular dysfunction, heart failure, or both.
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.


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.
Pouleur
Anne-Catherine
AC
Cardiovascular Division, Brigham and Women's Hospital, Boston, MA 02115, USA.
Barkoudah
Ebrahim
E
Uno
Hajime
H
Skali
Hicham
H
Finn
Peter V
PV
Zelenkofske
Steven L
SL
Belenkov
Yuri N
YN
Mareev
Viacheslav
V
Velazquez
Eric J
EJ
Rouleau
Jean L
JL
Maggioni
Aldo P
AP
Køber
Lars
L
Califf
Robert M
RM
McMurray
John J V
JJ
Pfeffer
Marc A
MA
Solomon
Scott D
SD
D000368:Aged; D000369:Aged, 80 and over; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications / Q000401:mortality* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality* / Q000503:physiopathology; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000401:mortality* / Q000503:physiopathology