Relationship between obstructive coronary artery disease and abnormal stress testing in patients with paroxysmal or persistent atrial fibrillation.

Atrial fibrillation (AF) has been linked to the presence of underlying coronary artery disease (CAD). However, whether the higher burden of CAD observed in AF patients translates into higher burden of myocardial ischemia is unknown. In 87 patients (71% male, mean age 61 ± 10 years) with paroxysmal or persistent AF and without history of CAD, MSCT coronary angiography and stress testing (exercise ECG test or myocardial perfusion imaging) were performed. CAD was classified as obstructive (≥50% luminal narrowing) or not. Stress tests were classified as normal or abnormal. A population of 122 patients without history of AF, similar to the AF group as to age, gender, symptomatic status and pre-test likelihood, served as a control group. Based on MSCT, 17% of AF patients were classified as having no CAD, whereas 43% showed non-obstructive CAD and the remaining 40% had obstructive CAD. A positive stress test was observed in 49% of AF patients with obstructive CAD. Among non-AF patients, 34% were classified as having no CAD, while 41% showed non-obstructive CAD and 25% had obstructive CAD (P = 0.013 compared to AF patients). A positive stress test was observed in 48% of non-AF patients with obstructive CAD. In conclusion, the higher burden of CAD observed in AF patients is not associated to higher burden of myocardial ischemia.