Prognostic implications of atrial fibrillation in patients with stable coronary artery disease: a systematic review and meta-analysis of adjusted observational studies

Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice. Despite the frequent coexistence with coronary artery disease (CAD), the prognostic independent implication of AF in patients with stable CAD remains controversial. Our aim was to perform a pairwise meta-analysis of adjusted observational studies comparing cardiovascular outcomes in patients with stable CAD with and without concomitant AF, in search of AF-specific prognostic implications. We performed random effect meta-analysis of binary outcome events in studies comparing stable CAD patients with versus without AF providing risk estimates adjusted for confounding variables. Literature search was performed in PubMed/MEDLINE and Google Scholar. Death was the primary endpoint of the analysis, while myocardial infarction, coronary revascularization and stroke secondary endpoints. 5 studies were included in the meta-analysis, encompassing a total of 30230 stable CAD patients (2844 with AF, 27386 without AF). Stable CAD patients with AF presented an independent increased risk of death (HR 1.39, 95% CI: 1.17-1.66) and stroke (HR 1.88, 95% CI: 1.45-2.45) compared to those without AF. Instead, risk of myocardial infarction (HR 0.90, 95% CI: 0.66-1.22) and coronary revascularization (HR 0.96, 95% CI: 0.79-1.16) did not differ in stable CAD patients with and without the arrhythmia. In patients with stable CAD, AF exerts an independent negative prognostic effect, increasing the risk of death and stroke. However, the small number of eligible studies included in this analysis highlights the astonishing lack of data regarding prognostic implications of concomitant AF in patients with stable CAD.