Documentation of impaired coronary blood flow by TIMI frame count method in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is associated with impaired coronary flow and diminished myocardial perfusion. In the present study we aimed to evaluate coronary blood flow by means of Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) in patients with AF in the absence of obstructive coronary artery disease (CAD).

METHODS: This prospective study initially enrolled 166 patients with AF and 332 age- and gender-matched control subjects without AF. After diagnostic coronary angiography, TFC was assessed in the participants without obstructive CAD, with 146 in the AF group and 150 in the control group.

RESULTS: The TFC for three major coronary arteries and the mean TFC were found to be significantly higher in AF patients compared to control subjects (34.1 ± 10.4 vs. 25.0 ± 10.4, 31.8 ± 9.7 vs. 23.7 ± 9.1, and 32.3 ± 9.5 vs. 24.1 ± 8.4 for each artery and 32.8 ± 9.2 vs. 24.3 ± 8.9 for mean TFC, p<0.001 for all comparisons). The mean TFC was 28.8 ± 7.9 in patients with paroxysmal AF, 33.7 ± 8.7 in those with persistent AF, and 39.0 ± 8.8 in those with long-standing or permanent AF (p<0.01 for all comparisons). After multivariate analysis, we found that the presence of AF remains to be independently associated with mean TFC. In AF group, baseline heart rate, left ventricular ejection fraction, AF duration and left atrium diameter were found to be independently associated with mean TFC.

CONCLUSIONS: Patients with atrial fibrillation in the absence of obstructive coronary artery disease have significantly higher TIMI frame counts for all three coronary vessels, indicating impaired coronary blood flow, compared to the control subjects without atrial fibrillation.