Risk markers of incident atrial fibrillation in patients with coronary heart disease.

BACKGROUND: In patients with coronary heart disease (CHD), atrial fibrillation (AF) is associated with increased morbidity and mortality. We investigated the associations between clinical risk factors and biomarkers with incident AF in patients with CHD. METHODS AND RESULTS: Around 13,153 patients with optimally treated CHD included in the STabilization of Atherosclerotic plaque By Initiation of darapLadIb TherapY (STABILITY) trial with plasma samples obtained at randomization. Mean follow-up time was 3.5 years. The association between clinical risk factors and biomarkers with incident AF was estimated with Cox-regression models. Validation was performed in 1,894 patients with non-ST-elevation acute coronary syndrome included in the FRISC-II trial. The median (min-max) age was 64 years (range 26-92) and 2,514 (19.1%) were women. A total of 541 patients, annual incidence rate of 1.2%, developed AF during follow-up. In multivariable models, older age, higher levels of NT-proBNP, higher body mass index (BMI), male sex, geographic regions, low physical activity, and heart failure were independently associated with increased risk of incident AF with hazard ratios ranging from 1.04 to 1.79 (P ≤ .05). NT-proBNP improved the C-index from 0.70 to 0.71. In the validation cohort, age, BMI, and NT-proBNP were associated with increased risk of incident AF with similar hazard ratios. CONCLUSIONS: In patients with optimally treated CHD, the incidence of new AF was 1.2% per year. Age, NT-proBNP as a marker of impaired cardiac function, and BMI were the strongest factors, independently and consistently associated with incident AF. Male sex and low physical activity may also contribute to the risk of AF in patients with CHD.

Risk of ischemic stroke and utility of CHA2 DS2 -VASc score in women and men with atrial fibrillation.

BACKGROUND: The magnitude of increased risk of stroke in women with atrial fibrillation (AF) remains uncertain. HYPOTHESIS: We investigated the risk of ischemic stroke and death in women and men with AF, and the risk associated with individual non-sex CHA2 DS2 -VASc risk factors. METHODS: Retrospective cohort study of 231 077 (48.1% women) nonselected patients with AF not receiving oral anticoagulation from 2006 to 2014. Data from cross-linked national Swedish registers. The outcome was the first occurrence of ischemic stroke or death. Median age was 82 and 75 years in women and men, respectively. Mean follow-up was 2.5 years. RESULTS: Hazard ratios, adjusted for non-sex CHA2 DS2 -VASc risk factors, for women vs men were 1.53, 95% CI: 1.49-1.58 for ischemic stroke and 1.24, 95% CI: 1.22-1.26 for death, respectively. When divided into age groups the differences in ischemic stroke rates between women and men were attenuated. In patients with only one non-sex CHA2 DS2 -VASc risk factor allotted 1 point, ischemic stroke rates per 100 person-years were 1.22 in women (n = 9838) and 1.02 in men (n = 15 609), respectively, P < .006. In both women and men, age of 65 to 74 years was associated with higher ischemic stroke risk compared to other non-sex CHA2 DS2 -VASc risk factors allotted 1 point. CONCLUSIONS: The risk of ischemic stroke was 1.5-fold higher in women compared to men but this association appears to be the result of confounding by age. In the low risk end, the CHA2 DS2 -VASc risk score underestimates the ischemic stroke risk conferred by age 65 to 74 years, while it overestimates the risk conferred by female sex.