Systemic Inflammation and Recurrence After Atrial Fibrillation–Related Stroke

BACKGROUND AND OBJECTIVES: The residual recurrence risk after atrial fibrillation (AF)-related stroke is high despite anticoagulation, thereby necessitating new therapies. The importance of inflammation in AF is increasingly recognized. However, patients with AF-related stroke were excluded from recent trials of anti-inflammatory therapies. It is uncertain whether associations between IL-6/high-sensitivity C-reactive protein (hsCRP) and poststroke recurrence are modified by AF status. In this study, we aimed to analyze the association between IL-6/hsCRP and recurrence according to AF history. METHODS: We leveraged individual participant data from studies identified by systematic review. We analyzed associations between IL-6/hsCRP and recurrent stroke/major adverse cardiovascular events (MACEs) (defined as fatal or nonfatal recurrent stroke or major coronary events) using multivariable Cox regression analyses (conditional logistic regression for 1 study) adjusted for age, sex, index event, cardiovascular risk factors, and medication use, stratified by AF status. RESULTS: unit for MACE was 1.17 (1.07-1.27) in patients without AF and 1.10 (0.91-1.34) in those with AF. The corresponding aRR for recurrent stroke was 1.15 (1.05-1.25) and 1.12 (0.91-1.37) in patients without and with AF, respectively. DISCUSSION: These data highlight the importance of inflammatory mechanisms in vascular recurrence irrespective of AF, provide rationale for the inclusion of patients with AF in trials of anti-inflammatory therapy, and support a selection approach in future trials based on elevated inflammatory marker levels, rather than stroke etiology alone.