Risk of sudden cardiac death is highest in the early period following a heart attack

Even with modern medical treatment, patients who have experienced a heart attack remain at increased risk for sudden death after they are discharged from the hospital. In an effort to better understand who to treat and when, researchers at Brigham and Women’s Hospital (BWH), in collaboration with an international research team, studied sudden death in 14,609 men and women who’d had a heart attack and were enrolled in the VALIANT Trial (Valsartan in Acute Myocardial Infarction Trial).

The researchers found that the risk of sudden death was highest in the first 30 days following a heart attack, and that the risk declined rapidly with time. The risk of sudden death was particularly high in patients with reduced left ventricular (main heart pump) function. Researchers also found, unexpectedly, that patients with better left ventricular function were also at increased risk of dying suddenly during this early period. These findings suggest that new treatments focused on patients in that highest risk period could lead to a substantial saving of lives after a heart attack. Details are in the June 23 issue of the New England Journal of Medicine.

According to lead author Scott D. Solomon, director of noninvasive cardiology at BWH, it is important to better understand the threshold of risk. “This study confirms that patients who have a decreased left ventricular ejection fraction after heart attack are at high risk of sudden death in the early period after an event. However, we also found that even patients with better cardiac function were also at risk during the early period. Although this risk of dying suddenly due to heart rhythm disturbances is greatest in the first few days after a heart attack – usually when the patient is in the hospital – we found that a substantial number of patients die suddenly and unexpectedly after hospital discharge.

“As we discharge patients earlier and earlier after heart attack, we need to consider this risk. While we currently have good long-term therapies for patients at high risk for sudden death – notably implantable defibrillators – the fact that this risk is very high early on, then declines, would support the development of short-term strategies that might lead to savings lives during this particularly high risk period.”