June 29, 2005
By Sahar
Bedrood B.S. and Asher Kimchi M.D.
Boston,
MA - One of the most concerning complications of an acute
myocardial infarction (MI) is sudden death. The risk of sudden
death is greatest within a few hours after MI and decreases
dramatically thereafter. Scott D. Solomon, M.D., et al from the
Brigham and Women’s Hospital in Boston, MA studied the incidence
and timing of sudden unexpected deaths or cardiac arrests after
MI in patients with left ventricular dysfunction, heart failure
or both. Their study, published in the June 23, 2005 issue of
The New England Journal of Medicine shows that the risk of
sudden death is highest in the first 30 days after myocardial
infarction among patients with left ventricular dysfunction,
heart failure or both.
Though the risk of sudden death after MI is believed to
increase, then decrease rapidly, the extent and time course of
this change is risk have not been well studied until the
Valsartan in Acute Myocardial Infarction Trial (VALIANT) study
was set forth by Solomon et al. VALIANT was a randomized
controlled study with valsartan, captopril or both in 14,703
patients with a first or subsequent acute myocardial infarction
complicated by heart failure, left ventricular systolic
dysfunction or both. All patients had an ejection fraction of no
more than 40 percent or radiologic evidence of heart failure
complicating their myocardial infarction.
Of 14, 609 patients, 1067 (7 percent) had an event a median of
180 days after MI: 903 died suddenly and 164 were resuscitated
after cardiac arrest. The risk was highest in the first 30 days
after myocardial infarction –1.4 percent per month (95 percent
confidence interval, 1.2 to 1.6 percent) and decreased to 0.14
percent per month after 2 years (95 percent confidence, 0.11 to
0.18 percent). Patients with a left ventricular ejection
fraction of 30 percent or less were at highest risk in this
early period (rate, 2.3 percent per month; 95 percent confidence
interval 1.8 to 2.8 percent). Nineteen percent of all sudden
deaths or episodes of cardiac arrest with resuscitation occurred
within the first 30 days after myocardial infarction, and 83
percent of all patients who died suddenly did so in the first 30
days after hospital discharge. Each decrease of 5 percentage
points in the left ventricular ejection fraction was associated
with a 21 percent adjusted increased in the risk of sudden death
or cardiac arrest with resuscitation in the first 30 days.
The results of the analysis made by the VALIANT study confirms
that patients with left ventricular dysfunction, heart failure
or both are at higher risk for sudden death or cardiac arrest
with resuscitations after myocardial infarction. The risk is
greatest in the early time period after myocardial infarctions
and among patients with the lowest ejection fraction and
declines over time. It may be beneficial to consider early
intervention strategies in patients who are at an increased risk
of sudden death.
Co-authors: Steve Zelenkofske, D.O., John J.V. McMurray, M.D.,
Peter V. Finn, M.D., Eric Velazquez, M.D., Geroge Ertl, M.D.,
Adam Harsanyi, M.D., Jean L. Rouleau, M.D., Aldo Maggioni, M.D.,
Lars Kober, M.D., Harvey White, D.Sc., Frans Van de Werf, M.D.,
Ph.D., Karen Pieper, M.D., Robert M. Califf, M.D., and Marc A.,
Pfeffer, M.D., Ph.D.
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