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CHICAGO – Risk of sudden cardiac death increases following a
heart attack, but researchers at the Duke Clinical Research
Institute say the factors that predict such deaths change over
time. The findings were presented today at the annual meeting
of the American College of Cardiology.

Duke investigators reviewed the records of 14,703 patients
enrolled in the VALIANT trial (Valsartan in Acute Myocardial
Infarction Trial), a study that showed that risk of sudden
death is greatest in the first 30 days after a heart
attack.

"Patients who die in the first few weeks after a heart
attack can experience abnormal heart rhythms that can lead to
sudden death," says Dr. Jonathan Piccini, a cardiology fellow
at Duke and the lead author of the study. "Ironically, however,
multiple studies show that implantable defibrillators – devices
that can stop life-threatening heart rhythms – don't really
seem to alter death rates during that period. So it occurred to
us that there may be other important risk factors for sudden
death and that these risk factors may change with time."

Piccini and colleagues examined patient outcomes during four
time periods in the VALIANT trial: in-hospital to discharge,
discharge to 30 days, 30 days to six months and six months to
three years.

They found that by 30 months, 7.3 percent of the patients
had died of sudden cardiac death, and that those who died
tended to be older, were more likely to have diabetes, had not
been prescribed a beta-blocker and had experienced a heart
attack before enrolling in the VALIANT trial.

"We also found that while low blood pressure and a high
resting heart rate are strong initial predictors of sudden
cardiac death, over time, heart failure and an earlier heart
attack were even more robust predictors," says Piccini.

One risk factor that was consistently predictive over time
was impaired kidney function. Piccini says the reasons why are
not clear, but poor kidney function appears to be associated
with higher likelihood of arrhythmia in general, but
particularly in patients who have suffered a heart attack.

"These results are important because they may help
cardiologists better understand their patients' risks for
abnormal heart rhythms after a heart attack. This, in turn,
could lead to more appropriate and better care," says
Piccini.