Atrial fibrillation is independently associated with impaired myocardial perfusion

A characteristic feature of obstructive coronary artery disease (CAD) is impaired myocardial blood flow (MBF). Previous studies have shown that atrial fibrillation (AF) is also associated with reduced hyperemic MBF. However, it is unknown whether an independent association exists between AF and MBF in symptomatic patients with suspected obstructive CAD. We studied 874 patients at Kuopio University Hospital (Finland) who underwent coronary computed tomography angiography (CCTA) and [15O]H2O myocardial perfusion positron emission tomography due to suspected obstructive CAD in 2017-2023. The final cohort comprised 31 AF patients and 120 propensity score-matched sinus rhythm (SR) patients. The matching criteria were age, sex, body mass index, number of traditional risk factors for CAD (0-5), calcium score, and total CCTA status (i.e., the overall severity of CCTA findings). Global hyperemic MBF was lower in AF patients than in SR patients (median 1.9 mL/g/min [IQR 1.4-2.6 mL/g/min] vs. 3.0 mL/g/min [IQR 2.4-3.6 mL/g/min], p < 0.001). Impaired hyperemic MBF (< 2.3 mL/g/min in ≥ 1 segment) was more frequent in AF patients (n = 25/31, 81%) than in SR patients (n = 50/120, 42%, p < 0.001). Furthermore, the presence of AF was independently associated with reduced hyperemic MBF in three multivariate general linear models (p < 0.001 in each model). To summarize, AF was independently associated with impaired hyperemic MBF in patients with suspected obstructive CAD. This association should be considered in clinical practice when interpreting the results of myocardial perfusion imaging in patients with AF.