Predictors of cardiac arrest among patients with post-myocardial infarction ejection fraction greater than 35%

The objective of this study was to determine the risk factors for sudden cardiac arrest (SCA) among patients with a post-myocardial infarction ejection fraction greater than 35% in a large, contemporary, real-world population. The sample consisted of 31,286 patients with incident myocardial infarction and post-MI ejection fraction >35%.

• The mean age of patients was 64.1 (54.9-74.0) years and 39% were women.
• At the time of infarction, 94% of participants had a history of coronary heart disease and 35% of them had the comorbidity of diabetes mellitus.
• The mean post-infarction ejection fraction was 55% (45%-60%), and 32% of patients had an ejection fraction between 35% and 50%.
• It was a requirement that all patients had undergone coronary angiography. 19,171 (61%) had had percutaneous coronary intervention and 4065 (13%) coronary artery bypass surgery.
• Post‐MI beta blockers and angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers were prescribed in 81% and 62% of the patients, respectively.
• The risk factors identified in the referral cohort were: absence of coronary revascularization at the time of incident myocardial infarction, revascularization by coronary artery bypass surgery (as opposed to percutaneous coronary intervention) at the time of incident myocardial infarction, post-infarction ejection fraction of 35% to 50%, black race,history of heart failure, history of chronic obstructive pulmonary disease, history of renal failure, history of diabetes mellitus, antiarrhythmic therapy, absence of beta-blocker therapy, and markedly elevated serum troponin levels (>7.5 ng/mL).

• Patients with an ejection fraction (EF) greater than 35% after a myocardial infarction have a substantial risk of sudden cardiac arrest (SCA), with an estimated cumulative probability of 1.8% within the first year.
• Among patients with an ejection fraction greater than 35% after a myocardial infarction who underwent coronary angiography, a risk model was identified to detect patients at higher risk of sudden cardiac arrest (SCA). This model includes: lack of coronary revascularization, an ejection fraction between 35% and 50% after the infarction, Black race, history of chronic obstructive pulmonary disease, history of renal failure, antiarrhythmic therapy, and absence of beta-blocker therapy.
• After adjusting for other risk factors, the risk of sudden cardiac arrest (SCA) was higher in those with an ejection fraction between 36% and 39%. This risk was lower in patients with an ejection fraction ≥45%.

Patients with a post-myocardial infarction ejection fraction greater than 35% have a substantial annual risk of sudden cardiac arrest (SCA). Utilizing a risk model that takes into consideration acute coronary revascularization, ejection fraction, race, renal failure, chronic obstructive pulmonary disease, antiarrhythmic therapy, and beta-blocker therapy may be useful to detect patients at higher risk of SCA. This additional stratification could benefit individuals by enabling closer monitoring.

REFERENCE

Predictors of Sudden Cardiac Arrest Among Patients With Post‐Myocardial Infarction Ejection Fraction Greater Than 35%. Selçuk Adabag et al.

https://www.ahajournals.org/doi/10.1161/JAHA.121.020993