“…6 The cause of the increased baseline platelet reactivity in anginal NCA patients remains to be ascertained. In these patients, a coronary microvascular dysfunction has been reported, 29,30 with several abnormalities potentially capable of promoting platelet activation, including endothelial dysfunction (with possible impaired NO production [31][32][33] and increased endothelin release 34,35 ), abnormal autonomic function, 36 increased sodiumhydrogen exchanger activity, 37,38 and oxidative stress. 39 On the other hand, during stress conditions, an enhanced myocardial release of adenosine, the main metabolic regulator of coronary blood flow, has been hypothesized to occur in patients with syndrome X and to have a major role in determining the main pathophysiological features of the syndrome.…”