Electrical cardioversion ups brady-arrhythmic event risk in older adults

Electrical cardioversion (ECV) increases the 30-day risk of brady-arrhythmic events, especially in older individuals, a new study has found.

Drawing from Danish nationwide registers, the researchers identified 20,725 atrial fibrillation (AF) patients (median age 66 years, 73 percent men) who received their first nonemergent ECV between 2005 and 2018. The primary outcome was a diagnosis of brady-arrhythmia (unspecified bradycardia, sinoatrial block, or advanced atrioventricular block) or a procedural code for pacing, whichever came first.

During the first 30 days after ECV, 290 brady-arrhythmic events occurred along with 62 all-cause deaths. There was a notable effect of age, such that the risk of such events grew from 0.6 percent in patients aged 40 years to 1.2 percent and 2.7 percent in participants 65 and >80 years of age, respectively. In 90-year-olds, the 30-day risk of brady-arrhythmic events was 5.1 percent.

Other risk factors, as identified by logistic regression analysis, included ischaemic heart disease (odds ratio [OR], 2.41, 95 percent confidence interval [CI], 1.87–3.10), valvular AF (OR, 3.04, 95 percent CI, 2.13–4.34), heart failure (OR, 1.58, 95 percent CI, 1.20–2.07), cardiomyopathy (OR, 2.60, 95 percent CI, 1.65–4.10), diabetes (OR, 1.75, 95 percent CI, 1.27–2.40), and syncope (OR, 2.63, 95 percent CI, 1.61–4.29).

“Using a nationwide study population of AF patients undergoing their first registered ECV, we uncovered that the risk of brady-arrhythmic complications was low in the young and middle-aged but relatively high in older patients,” the researchers said. “These data should raise awareness regarding the risks of brady-arrhythmic events, especially in older patients undergoing ECV.”