Exhaustion of coronary vasodilatory reserve in the resting state: Clinical characteristics and long-term outcomes after intervention.

Abstract

Resting coronary blood flow approximates flow with maximal vasodilation in very severe coronary stenosis. We studied the incidence of exhausted vasodilatory reserve by FFR, its clinical characteristics and long-term prognosis after FFR guided percutaneous coronary intervention (PCI). Consecutive patients undergoing FFR-guided PCI for coronary stenosis with reduced resting blood flow (baseline Pd/Pa < 0.8) were included. Basal maximal vasodilation (BMV) was defined as less than 5% difference between resting Pd/Pa and FFR, that is, FFR-baseline Pd/Pa < 0.05. Of 658 vessels that underwent FFR-guided PCI in 602 patients, 151 vessels had resting blood flow in the ischemic range (baseline Pd/Pa ≤ 0.8) and were included in the analysis. Of these, 28 lesions in 28 patients met criteria for BMV (4.25% of the entire registry and 18.5% of those with the reduced basal coronary flow). Stenosis severity was a significant predictor of the presence of BMV. In long term follow-up (median 106 ± 3.6months), BMV was not associated with increased target vessel revascularization (TVR) or major adverse cardiac event compared to non-BMV(OR 1.9, 95% CI 0.7-4.8, p-value 0.2 and OR 1.3, 95% CI 0.75-2.5, p=0.3, respectively). Low baseline Pd/Pa that approximates fractional flow reserve (exhausted vasodilatory reserve) defines a subgroup of patients with severe coronary artery stenosis. Prognosis, when treated with PCI along with medical therapy, appears similar to those with intact vasodilatory reserve.