Coronary Heart Disease Mortality Often Attributed to Sudden, Arrhythmic Death

Patients with coronary heart disease (CHD) and a history of myocardial infarction (MI) examined prospectively every 6 months revealed that sudden and/or arrhythmic death (SAD) occurred most often at home and was associated with ventricular tachyarrhythmia in most patients, according to a recent study published in JAMA Cardiology.

Baseline demographics from patients (n=5761) with CHD and a history of MI who did not qualify for implantable cardioverter defibrillator therapy on the basis of left ventricular ejection fraction (LVEF) ≥35% or New York Heart Association heart failure class I (LVEF >30%) were collected and prospectively tracked every 6 months.

The primary end point was SAD, which was defined as death or fatal cardiac arrest occurring within 1 hour of symptom onset without evidence for a noncardiac cause. Clinical risk factors were compared between groups to determine associations with SAD.

A total of 559 (10%) participants died during the median follow-up of 3.9 years. Of those who died, 202 (36.1%) were considered cardiac-related deaths, and 114 (20.4%) were defined as SADs. Further analysis of the SAD cases revealed clinical history pertaining to angina in 75% of cases, and 19% reported symptoms that could have been consistent with unstable angina within 1 month of SAD. Many patients with SAD (58%) did not report symptoms immediately before SAD. Further statistical analysis of participants who underwent implantable cardioverter defibrillator implantation after study enrollment projected a reduction in total mortality by 13%.

The study authors wrote, “Sudden and/or arrhythmic death was unheralded in the majority, occurred most commonly at home, and when monitored, was associated with ventricular tachyarrhythmia in most patients.”

They also noted their data challenged traditional stratification of SAD risk, suggesting, “In this study, SAD risk was continuously and inversely associated with LVEF, and further, the relative risk of SAD was greater than non-SAD in patients with an LVEF of 40% to 49%.” They stressed that integrating of a more continuous assessment of LVEF into future risk stratification efforts could improve risk prediction for SAD.

Reference

Chatterjee N, Moorthy V, Pester J, et al. Sudden death in patients with coronary heart disease without severe systolic dysfunction [published online May 2, 2018]. JAMA Cardiol. doi:10.1001/jamacardio.2018.1049