Temporal relations between atrial fibrillation and ischemic stroke and their prognostic impact on mortality

• Introduction: Atrial fibrillation (AF) and stroke are common diseases and AF is a well-established risk factor for stroke. The physiological mechanism of atrial dysfunction, disturbed hemodynamics and arterial thromboembolism links the pathologies. However, limited evidence is available on the temporal relationship between stroke and AF and the impact of subsequent disease onset on mortality in the community.Methods and results: Across five prospective community cohorts (DanMONICA, FINRISK, Moli-Sani project, Northern Sweden MONICA study, The Tromsø Study) of the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE)-project we assessed baseline cardiovascular risk factors in 101164 individuals, median age 46.1 (25th, 75th percentile 35.8, 57.6) years, 48.4% men. We followed them for incident stroke and AF and determined the relation of subsequent disease diagnosis with overall mortality. Follow-up (FU) for stroke and AF was based upon linkage with national hospitalization registries or administrative registries for ambulatory visits to specialized hospitals.Over a median FU of 16.1 years N=4556 individuals were diagnosed solely with AF, N=2269 had a stroke but no AF diagnosed, and N=898 developed both stroke and AF during FU. Participants who developed either AF or stroke as the index event revealed a similar baseline risk factor profile. Temporal relations showed a peak of the diagnosis of both diseases within the years around the diagnosis of the other disease. The highest incidence rates of stroke were observed within a five-year interval prior to AF diagnosis. Cox regression showed an association of baseline stroke with diagnosis of AF during FU (hazard ratio (HR) 1.29; 95% confidence interval (CI) 1.11–1.50; p<0.001).In multivariable-adjusted Cox regression analyses with time-dependent covariates excluding individuals with diagnosis of both AF and stroke or death within 30 days, subsequent diagnosis of AF after stroke was associated with a higher overall mortality (HR, 3.51; 95% CI 1.87–6.59; p<0.001); subsequent stroke after the diagnosis of AF was associated with a HR of 2.39 (95% CI 1.59–3.60; p<0.001).Conclusions: Stroke and AF are common comorbidities in older adults with an overlapping risk factor profile. The temporal relations appear to be bidirectional, although uncertainty regarding disease onset remains due to the often paroxysmal and asymptomatic nature of AF. Stroke may precede detection of AF by years. The subsequent diagnosis of both diseases significantly increases mortality risk. Whether targeting modifiable risk factors or improved screening for AF after stroke would improve survival needs to be determined.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kardiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cardiac and Cardiovascular Systems (hsv//eng)

Publication and Content Type

vet (subject category)

art (subject category)