TDE-derived impaired post-PCI Coronary flow velocity reserve predicts MACE in patients who underwent LAD PCI

Abstract Background Coronary flow velocity reserve (CFVR) can be obtained noninvasively by stress transthoracic Doppler echocardiography (S-TDE). However, prognostic significance of S-TDE-derived CFVR after percutaneous coronary intervention (PCI) remains unknown. Purpose This study aimed to investigate the relationship between post-PCI CFVR and major adverse cardiac event (MACE). Methods This study prospectively included 200 patients with stable coronary artery disease who were scheduled for elective PCI of de novo, single, functionally significant left anterior descending (LAD) lesions at a single tertiary-care center between April 2019 and November 2022. All patients underwent fractional flow reserve (FFR)-guided elective PCI. Exclusion criteria were patients with previous coronary artery bypass graft surgery, left main coronary artery disease and periprocedural myocardial infarction as defined by the fourth universal definition of myocardial infarction. Eligible patients underwent pre- (1 day before) and post-procedural (3 days after) LAD coronary flow assessments by stress-TDE. CFVR was calculated as the ratio of the hyperemic peak diastolic flow velocity to the basal peak diastolic flow velocity. We also excluded the patients with suboptimal S-TDE imaging. Association between post-PCI physiological parameters and MACE (composite of cardiac death, myocardial infarction, heart failure and target vessel revascularization) were evaluated. Results A total of 174 patients were included in the final analysis after successful LAD PCI. MACE occurred in twenty-one (12.0%) patients during the follow-up (1.9 [0.9-2.5] years). Clinical demographics were similar in patients with versus without MACE. Post-PCI S-TDE-derived CFVR was lower in patients with versus without MACE (P = 0.023), while post-PCI FFR values tended to be lower in patients with versus without MACE, albeit not significant (P = 0.077). Receiver-operating characteristic curve analysis revealed that the optimal cut-off values of post-PCI FFR and post-PCI CFVR values to predict MACE were 0.83 and 1.70, respectively. Significant differences in the MACE were detected according to post-PCI FFR (≤ 0.83 versus > 0,83: 17.9 % versus 6.7 %, P = 0.035) and post-PCI CFVR (< 1.70 versus ≥ 1.70: 33.3% versus 8.2%, P = 0.001). On a multivariable Cox-proportional hazard analysis, patients with post-PCI CFVR < 1.70 had an increased risk for MACE (adjusted hazard ratio [HR] 4.75, 95% confidence interval [CI] 1.98-1