Risk Factors and Outcomes Associated with Atrial Fibrillation Detected after Intracerebral Hemorrhage.

Abstract

Background: Atrial fibrillation detected after stroke (AFDAS) refers to newly identified atrial fibrillation occurring after an index cerebrovascular event, most commonly ischemic stroke, but little is known about its occurrence and clinical implications in patients with spontaneous intracerebral hemorrhage (ICH). We aimed to characterize AFDAS risk factors in ICH and AFDAS' relationship with long-term ICH outcomes.

Methods: We retrospectively analyzed consecutively admitted and enrolled patients with spontaneous ICH to a single tertiary comprehensive stroke center between 2009 and 2018 who underwent continuous cardiac monitoring. Patients were categorized as having sinus rhythm [SR (reference)], atrial fibrillation detected after stroke (AFDAS, defined here as atrial fibrillation (AF) detected during the index ICH hospitalization), and known AF. Demographic, clinical, imaging, and hospitalization complication data were compared across rhythm groups. Poor modified Rankin scale (mRS 4-6) at 3-month follow-up was assessed as the primary clinical outcome. Multivariable logistic regression assessed independent relationships of AFDAS with poor outcomes adjusting for demographics, ICH severity, and AFDAS risk factors.

Results: Amongst 532 patients with ICH, AFDAS occurred in 5% on median ICH hospital day 3. Outside of increased hypertension prevalence, patients with AFDAS had fewer baseline cardiovascular comorbidities compared with patients with known AF yet had similar cardiac risk profiles and structural/function measurements on echocardiogram compared with patients with SR. Baseline ICH characteristics and severity were similar between groups, but patients with AFDAS were more likely to have hospitalization infection complications (67% vs. 32% in known AF, 42% in SR, p = 0.01). Poor 3-month outcome was more common in patients with AFDAS (94%) compared with those with known AF (78%) and sinus rhythm (65%) (p = 0.01), and AFDAS was independently associated with poor outcomes [adjusted odds ratio (OR) 11.07, 95% confidence interval (CI) 1.30-94.27].

Conclusions: We identified that patients with ICH and AFDAS have less severe cardiovascular comorbidities yet are more likely to have worse long-term outcomes. Further prospective studies are required to confirm these results and characterize drivers for AFDAS development and links between AFDAS and poor ICH outcomes to assess whether AFDAS detection and prevention can improve ICH.