Platelet function disorder in patients with coronary slow flow

Background: Some patients evaluated for chest pain with angiographically normal coronary arteries show coronary slow flow phenomenon (CSFP) on angiography. Slow flow of dye in epicardial coronary arteries is also not an infrequent finding in patients during routine coronary angiography. The precise pathophysiology of CSFP is not known yet. Hypothesis: This study investigates the presence of platelet function disorders in patients with CSFP. Methods: The patient group included 24 patients with CSFP detected by coronary angiography via the TIMI "frame count" method, and a control group included 23 patients with normal coronary flow. Platelet aggregability induced by use of ristocetin, collagen, and adenosine diphosphate (ADP), was measured from all blood samples in both control and patient groups. Results: The ratio of platelet aggregability increased significantly in patients with CSFP compared with patients with normal coronary flow (ristocetin 57.6 +/- 15 vs. 45.4 +/- 17. 1, collagen 62.9 +/- 16.4 vs. 48.9 +/- 25.3, ADP 59.4 +/- 18 vs. 42.4 +/- 15.2, p < 0.05). Conclusion: Platelet aggregability is increased in patients with CSFP.