Reduced atrial blood flow in patients with coronary artery disease

BACKGROUND: The thrombolysis in myocardial infarction (TIMI) frame count and TIMI perfusion grade are measures of epicardial and microvascular ventricular coronary artery blood flow, respectively. Similar angiographic methods for measuring atrial coronary artery blood flow have not been developed. OBJECTIVE: To utilize two new angiographic measures of atrial blood flow (ABF), the atrial frame count (AFC) and the atrial perfusion score (APS), to determine whether ABF differs between patients with and without coronary artery disease (CAD). METHODS: The AFC was defined as the number of frames for dye to reach standardized, distal atrial arterial landmarks during coronary angiography. The APS was utilized as a measure of microvascular atrial perfusion. AFCs were measured in 36 patients prior to isolated coronary artery bypass grafting (CABG), isolated valve surgery or in control patients (with neither CAD nor valvular disease). RESULTS: Sinus node artery and left atrial branch AFCs were higher (that is, ABF was reduced) in patients with CAD undergoing CABG than in those undergoing valve surgery (P < 0.05) or in control patients (P < 0.05). The APS was reduced in 63% of CAD patients but in only 5% of those without CAD (P < 0.001). The severity of CAD was a significant predictor of decreased ABF independent of the degree of proximal epicardial stenosis (P < 0.03). CONCLUSIONS: ABF is measurable with the AFC and APS. A significant reduction in ABF is present in patients with CAD undergoing CABG compared to patients without CAD. This reduction appears to be related to the overall severity of CAD independent of the degree of proximal stenosis.