Reduction of Coronary Flow Velocity Reserve as the Main Driver of Prognostically Beneficial Coronary Revascularization

Background

Regional wall motion abnormality (RWMA) can be absent during stress echocardiography (SE) in patients with chronic coronary syndromes (CCS) and angiographically significant coronary artery disease (CAD) despite a reduction of coronary flow velocity reserve (CFVR).

Objectives

To assess the value of a physiology-driven approach, based on CFVR, to coronary revascularization in patients with physiologically and anatomically significant disease of the left anterior descending (LAD) coronary artery.

Methods

In a 3-center, observational study with retrospective analysis of prospectively acquired data, 749 patients with CCS, CFVR of the LAD ≤2.0, and ≥50% diameter stenosis of the LAD were enrolled. All patients were evaluated with dipyridamole (0.84 mg/kg in 6’) SE. Patients were followed for 6.4 ± 4.5 years for the outcome of all-cause death.

Results

Inducible RWMA was present in 295 patients (39%). Coronary flow velocity reserve was lower in patients with inducible RWMA compared to those without (1.51 ± 0.28 vs 1.65 ± 0.25; P < .001). Coronary revascularization was performed in 514 (69%) patients (388 with percutaneous coronary intervention, 126 with coronary artery bypass surgery). Of them, 226 exhibited inducible RWMA and 288 exhibited isolated reduction of CFVR. During the follow-up, 185 (25%) deaths occurred. The 10-year survival in the entire study population was 70%. The survival at 10 years was markedly lower in conservatively treated patients compared to invasively treated patients (53 vs 76%; P < .0001), with no significant difference between those with solitary reduction of CFVR and reduction of CFVR accompanied by concurrent inducible RWMA. Propensity score–weighted all-cause mortality risk was significantly higher for conservative than for invasive strategy (propensity score adjusted hazard ratio = 2.12; 95% CI, 1.51–2.96; P < .0001).

Conclusions

In patients with CCS and physiologically and anatomically significant LAD disease, coronary revascularization driven by a reduction in CFVR is accompanied by a prognostic benefit independently of the presence of inducible RWMA.