LAUSR

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Yuhan Corporation, Seoul, Korea. Although non-obstructive coronary artery disease (CAD) was a relatively common finding in patients undergoing coronary angiography (CAG), it had previously been characterized as "insignificant CAD" and underestimated in importance. However, recent studies have increasingly showed that non-obstructive CAD is also associated with poor clinical outcomes. But the long-term clinical impact of multi-vessel involved non-obstructive CAD are not yet well-known. The aim of the present study was to determine the long-term clinical impact on patients with multi-vessel involved non-obstructive CAD. A total of 2,083 patients without obstructive CAD and revascularization history were enrolled between January 2010 and December 2015. They were classified into 4 groups according to the number of vessels involved non-obstructive CAD (25%≤ luminal stenosis < 70%): 0, 1, 2, 3 diseased vessel (DV). We followed patients for 5 years. The primary outcome was major cardiovascular and cerebrovascular events (MACCEs) defined as a composite of cardiac death, myocardial infarction (MI) and stroke. The secondary outcomes were each component of the primary outcome and all-cause death. 2,083 patients were classified into four groups according to the number of non-obstructive DVs (0 DV: 251 [60%],1 DV: 506 [24%], 2 DV: 250 [12%], 3 DV: 76 [4.0%]). The occurrence of MACCEs numerically increased as the number of non-obstructive DV increased, especially in 3 DV (MACCEs, 0 DV: 78 [6.2%], 1 DV: 33 [6.5%], 2 DV: 17 [6.8%], 3 DV: 14 [18.4%], p<0.001). After adjustment, patients with non-obstructive 3 DV still showed significantly poorer clinical outcomes than 0 DV in terms of MACCEs, MI and stroke. (MACCEs: hazard ratio [HR] 2.09, 95% confidence interval [CI] 1.15-3.79, p=0.016; MI: HR 15.17, 95% CI 2.37-97.25, p=0.004, Stroke: HR 2.04, 95% CI 1.01-4.16), P=0.049) Conclusions. Multi-vessel involved non-obstructive CAD, especially in 3 DV, was associated with poor long-term (5 years) clinical outcomes. Theses finding suggested that more intensive treatment may be required in this subset of patients.