TIMI Frame Count and Adverse Events in Women with No Obstructive Coronary Disease: A Pilot Study from the NHLBI-Sponsored Women's Ischemia Syndrome Evaluation (WISE)

BACKGROUND: TIMI frame count (TFC) predicts outcomes in patients with obstructive coronary artery disease (CAD); it remains unclear whether TFC predicts outcomes in patients without obstructive CAD. METHODS: TFC was determined in a sample of women with no obstructive CAD enrolled in the Women's Ischemia Syndrome Evaluation (WISE) study. Because TFC is known to be higher in the left anterior descending artery (LAD), TFC determined in the LAD was divided by 1.7 to provide a corrected TFC (cTFC). RESULTS: A total of 298 women, with angiograms suitable for TFC analysis and long-term (6-10 year) follow up data, were included in this sub-study. Their age was 55±11 years, most were white (86%), half had a history of smoking, and half had a history of hypertension. Higher resting cTFC was associated with a higher rate of hospitalization for angina (34% in women with a cTFC >35, 15% in women with a cTFC ≤35, P<0.001). cTFC provided independent prediction of hospitalization for angina after adjusting for many baseline characteristics. In this cohort, resting cTFC was not predictive of major events (myocardial infarction, heart failure, stroke, or all-cause death), cardiovascular events, all-cause mortality, or cardiovascular mortality. CONCLUSIONS: In women with signs and symptoms of ischemia but no obstructive CAD, resting cTFC provides independent prediction of hospitalization for angina. Larger studies are required to determine if resting TFC is predictive of major events in patients without obstructive coronary artery disease.