Clinical role of post-angioplasty hyperemic microvascular resistances in chronic ischemic left ventricular dysfunction.

Abstract

To investigate the impact of hyperemic microvascular resistances (HMRs) on myocardial perfusion and contractility after percutaneous coronary intervention (PCI) in chronic ischemic left ventricular dysfunction (CILVD). The current retrospective study included 48 patients with CILVD of the left anterior descending territory undergoing HMRs assessment before and after PCI with a dual-sensor intracoronary pressure-flow wire. The severity of resting myocardial underperfusion and contractile dysfunction of the left anterior descending territory was scored as summed rest score (SRS-T) by single photon emission tomography, wall motion score index (WMSI-T) and left ventricular ejection fraction (LVEF) by transthoracic echocardiography before PCI and after 3 months. Patients were divided into two groups according to the mean post-PCI HMRs. Mean post-PCI HMRs were 2.05 ± 0.43 mmHg/cm/s; increased HMRs (i.e. >2 mmHg/cm/s) were found in 17 patients (35.4%, group B) (3.29 ± 0.77 mmHg/cm/s), whereas 31 patients (64.6%, group A) showed lower values (1.35 ± 0.34 mmHg/cm/s; P < 0.001). Pre-PCI HMRs, WMSI-T and SRS-T were similar among groups.After PCI, a significant improvement of LVEF, WMSI-T and SRS-T was observed only in group A (6.6 ± 7.4%, 0.44 ± 0.42 and 3.9 ± 2.9, respectively) compared with group B (1.3 ± 1.9%, 0.02 ± 0.07 and 1.1 ± 1.9; P = 0.011, P < 0.001 and P = 0.028, respectively).Post-PCI HMRs predicted the absence of improvement of LVEF and WMSI-T at a cutoff value of 1.95 mmHg/cm/s (area under the curve 0.69 and 0.73; P = 0.038 and 0.017, respectively), with a positive predictive value of 96 and 100%, respectively. Increased post-PCI HMRs may predict the lack of functional improvement of the revascularized myocardium in CILVD.