Tuesday, April 1, 2008

ACC presentation: Warning signs of sudden cardiac death after heart attack
By Kelly Winget

Sudden cardiac death is a devastating complication following a heart attack, but in a new study, DCRI researchers analyzed and identified risk factors to help predict which patients have the greatest risk and help improve prevention efforts. They found that risk factors can change over time.

The DCRI's Jonathan Piccini, MD, a cardiology fellow and lead author of the study, presented the findings at the American College of Cardiology 2008 Scientific Sessions.

A percentage of patients who die within the first few weeks after having a heart attack experience abnormal heart rhythms that can lead to sudden cardiac death (SCD). SCD occurs suddenly and unexpectedly in otherwise stable patients. One approach to countering SCD has been to use implantable defibrillators to correct the heart rhythms. However, recent studies have shown that defibrillators don't significantly impact the death rate during the first few weeks following a heart attack.

Researchers reviewed data on the more than 14,000 patients enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) trial. They reviewed patient outcomes over four time periods: in-hospital to discharge, discharge to 30 days post-discharge, 30 days to six months after the heart attack and six months to three years after the heart attack. Results from the VALIANT trial showed the greatest risk of SCD occurred within the first 30 days after a heart attack.

After three years of follow-up, researchers found that approximately 7 percent of patients had died from sudden cardiac death. On average, the patients who died were the older patients, with a median age of 70. The patients often had had a history of diabetes and many were not prescribed a beta-blocker to control blood pressure. Many had also experienced a heart attack before they were enrolled in the VALIANT trial.

One of the findings was that heart failure and a prior heart attack were better predictors of SCD over a longer time, and low blood pressure and a high resting heart rate were better initial risk factor predictors.

Patients with impaired kidney function were consistently at higher risk. Researchers believe that poor kidney function is associated with a greater likelihood of having abnormal heart rhythms, especially in patients who have had heart attacks.

Researchers hope the study results will help improve post-heart attack care by providing better insight into the risk factors for SCD.

Other DCRI researchers involved in the study are Karen Pieper, Sana Al-Khatib, MD, Rob Califf, MD, and Eric Velazquez, MD.