Risk of sudden cardiac death greatest within 30 days of heart attack

The risk of sudden cardiac death following a heart attack has dropped by more than 40% in the last 25 years, however new research suggests that heart attack patients are still at heightened risk of sudden cardiac death within the first 30 days after their heart attack.

The study of 2997 heart attack patients, of which 284 (24%) died from sudden cardiac death, revealed that the incidence of sudden cardiac death within the 30 days following heart attack is 1.2% - four times higher than expected. After 30 days, the risk of death from sudden cardiac death drops to just 1.2% per annum, which is actually lower than the incidence of sudden cardiac death in the general population.

Recurrent ischemia did not appear to affect risk of sudden cardiac death, however heart failure was found to markedly increase the risk of sudden cardiac death. The risk of sudden cardiac death among patients who developed heart failure was 2.5% both in the first 30 days following heart attack and for each subsequent year.

The authors concluded: “In the community, the risk of sudden cardiac death is the highest during the first month after myocardial infarction when it markedly exceeds the rate in the general population. Among 30-day survivors, the risk of sudden cardiac death declines rapidly but it is markedly increased by the occurrence of heart failure during follow-up. This underscores the importance of continued surveillance of patients after myocardial infarction and the dynamic nature of risk stratification.”

Adabag AS, Thernau TM, Gersh BJ, Weston SA, Roger VL. Sudden death after myocardial infarction. JAMA 2008;300:2022-2029.