Cardiac arrest prevalence low 90 days after MI
Researchers observed a less than 0.3% prevalence of out-of-hospital cardiac arrest 90 days after MI, according to study data published in the Journal of the American College of Cardiology.
Jonas Faxén, MD, PhD, from the department of cardiology at Karolinska University Hospital, Stockholm, and colleagues evaluated data from the Swedish Cardiopulmonary Resuscitation Registry and the Swedish Pacemaker and Implantable Cardioverter-Defibrillator Registry. The study included 121,379 patients with MI who underwent coronary angiography and were discharged alive from 2009 to 2017, and patients were followed up to 90 days.
Out-of-hospital cardiac arrest occurred in 349 patients (0.29%), and there were 2,194 (1.8%) deaths unrelated to out-of-hospital cardiac arrest withing 90 days of discharge, according to the researchers.
Researchers identified male sex, diabetes, estimated glomerular filtration rate less than 30 mL/min/1.73 m2, Killip class II or greater, new-onset atrial fibrillation/flutter and impaired left ventricular ejection fraction as independent predictors of out-of-hospital cardiac arrest. These predictors were assigned points, and based on those, patients were grouped into three categories with out-of-hospital cardiac arrest incidence ranging from 0.12% to 2% and incidence of death unrelated to out-of-hospital cardiac arrest ranging from with 0.76% to 11.7%.
When stratified by LVEF less than 40% alone, out-of-hospital cardiac arrest incidence was 0.2% to 0.76% and death unrelated to out-of-hospital cardiac arrest was 1.1% to 4.9%.
“Further research is needed to investigate whether a more differentiated strategy could selectively target patients at risk for sudden cardiac death and preferably arrhythmic death early after MI,” the researchers wrote. “Our results support previous evidence that LVEF alone does not do the job, and this is now shown in a large contemporary post-MI population as well.”
According to an accompanying editorial, the study took a novel approach in estimating the risk for arrhythmia-related death early after MI, specifically deaths potentially prevented by an ICD.
“Accumulating evidence makes it clear that mortality in the early phase of MI is decreasing, likely because of greater rates of revascularization and growing adherence to proven medical therapy,” David J. Wilber, MD, cardiologist and professor at Loyola University Medical Center in Hines, Illinois, wrote in the editorial. “Although it may be possible to identify a small group of early post-MI patients in whom a wearable cardioverter defibrillator or ICD may be life-prolonging, collectively, the data indicate that the opportunities for further improvements in early survival from these interventions in the current era may be limited.”