Excessive Atrial Ectopy and Short Atrial Runs Increase the Risk of Stroke Beyond Incident Atrial Fibrillation

AbstractBackgroundApproximately 30% of ischemic strokes have an unknown cause. Increased atrial ectopy (AE) increases the risk of atrial fibrillation (AF), but the risk of stroke in patients with increased AE is unknown.ObjectivesThis study aimed to examine whether increased AE and short atrial runs increase the risk of stroke beyond incident AF.MethodsData were collected during a 15-year follow-up of the Copenhagen Holter Study cohort with 678 men and women between 55 and 75 years of age, with no earlier history of cardiovascular disease, stroke, or AF. Study subjects underwent 48-h ambulatory electrocardiography, fasting blood tests, and clinical examination. Excessive supraventricular ectopic activity (ESVEA) was defined as the presence of either ≥30 premature atrial contractions (PACs)/hour daily or any runs of ≥20 PACs.ResultsNinety-nine subjects (15%) demonstrated ESVEA. After adjusting for baseline risk factors, ESVEA was associated with ischemic stroke when censoring subjects at time of AF (hazard ratio [HR]: 1.96; 95% confidence interval [CI]: 1.10 to 3.49) or when modeling AF as a time-varying exposure (HR: 2.00; 95% CI: 1.16 to 3.45). Among subjects with ESVEA who developed a stroke, 14.3% had diagnosed AF before their stroke. The incidence of stroke in subjects with ESVEA and a CHA2DS2-VASc (congestive heart failure, hypertension, age 75 years or older, diabetes mellitus, previous stroke or transient ischemic attack, vascular disease, age 65 to 74 years, female) score of ≥2 was 2.4% per year, comparable to the risk observed in AF. In day-to-day analysis, ESVEA was a consistent finding.ConclusionsESVEA was associated with an increased risk of ischemic stroke beyond manifest AF in this middle-aged and older population. Stroke was more often the first clinical presentation, rather than AF, in these study subjects

Left Atrial Volumes and Function, and Long‐Term Incidence of Ischemic Stroke in the General Population

Background Left atrial (LA) volumes and emptying fraction in the general population may address structural and functional aspects of atrial cardiomyopathy associated with long‐term risk of ischemic stroke in the absence of atrial fibrillation or prior stroke. We investigated the association between LA volumes and function and ischemic stroke. Methods and Results In a community‐based cohort, we measured LA minimal volume, LA maximal volume, and LA emptying fraction by transthoracic echocardiography. The primary end point was ischemic stroke. Participants with known atrial fibrillation or prior ischemic stroke were excluded, which resulted in 1866 participants. The mean age was 58±16 years, and 57% were women. During a median follow‐up of 16.5 years (interquartile range: 11.4–16.8 years), 176 (9.4%) ischemic strokes occurred. In multivariable cause‐specific regression models and competing risk models with death as a competing risk, LA emptying fraction was associated with ischemic stroke (hazard ratio [HR], 1.14 per 10% decrease [95% CI, 1.02–1.28]) and (subdistribution HR, 1.14 [95% CI, 1.01–1.29]). This association remained when adjusting for participants who developed atrial fibrillation during follow‐up (HR, 1.12 per 10% decrease [95% CI, 1.00–1.26]). Indexed LA volumes were not associated with ischemic stroke in the same models. LA emptying fraction and indexed LA volumes were not associated with all‐cause mortality. Conclusions Lower LA emptying fraction measured by transthoracic echocardiography was associated with future ischemic stroke independently of incident atrial fibrillation. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02993172