TCT-603 Relationship between epicardial pathophysiological disease patterns and microvascular function.

Abstract

Background: Coronary microvascular dysfunction (CMD) has been linked to diffuse atherosclerosis. The index of microvascular resistance (IMR) and microvascular resistance reserve (MRR) quantify microvascular function. Using the pullback pressure gradient (PPG), epicardial coronary artery disease (CAD) can be categorized as focal or diffuse. We studied the association between epicardial CAD patterns and CMD as defined by IMR or MRR. Method(s): This prospective, multicenter study enrolled patients with at least 1 epicardial lesion with an FFR <= 0.80. PPG was computed from manual hyperemic pullbacks. Given that our cohort has epicardial disease, we used IMR corrected (IMRcorr) in our analysis. CMD was defined as CFR <2.5 with IMRcorr >25 or MRR <3.0 using bolus thermodilution. Epicardial disease patterns were categorized based on the median PPG value as predominantly focal (PPG >=0.62) or diffuse. Patients underwent PCI, then repeat assessments of microvascular function. Result(s): In total, 242 patients (248 vessels) underwent invasive PPG, CFR, IMR, and MRR. The mean age was 68 +/- 10; 73% were male, and 34% were diabetic. The mean PPG, CFR, IMRcorr, and MRR were 0.62 +/- 0.16, 2.4 +/- 1.2, 17 +/- 12, 3.8 +/- 1.9. The percentage of patients diagnosed with coronary microvascular dysfunction (CMD) was 15% based on CFR and IMRcorr but 36% based on MRR. PPG demonstrated a positive correlation with IMRcorr (r = 0.23; 95% CI: 0.11-0.34; P < 0.001), but no correlation was observed with MRR (r = -0.1; 95% CI: -0.22 to 0.03; P = 0.93). IMRcorr was significantly higher in patients with focal vs diffuse disease (20 +/- 13 vs 15 +/- 9; P = 0.004), whereas MRR was similar between patients with focal and diffuse disease (3.7 +/- 1.9 vs 4.0 +/- 1.9; P = 0.30). Based on CFR and IMRcorr, CMD was more frequently observed in patients with focal CAD (21% vs 10%; P = 0.03). Based on MRR, CMD was equally prevalent in patients with focal or diffuse CAD (31% vs 41%; P = 0.11). Conclusion(s): In patients with epicardial disease, no overall association was detected between diffuse epicardial atherosclerosis and microvascular function. Based on MRR, CMD was present in a third of patients undergoing percutaneous coronary intervention and was equally prevalent in focal vs diffuse disease. Categories: IMAGING AND PHYSIOLOGY: Physiologic Lesion Assessment.Copyright © 2024