Synergistic diagnostic value of stress myocardial work and perfusion echocardiography in intermediate coronary lesions: a propensity score-matched analysis

Intermediate coronary lesions present a diagnostic challenge. We hypothesized that combining myocardial work (MW) and myocardial contrast echocardiography (MCE) during dobutamine stress could accurately identify functionally significant stenoses and potentially reflect underlying microvascular dysfunction. We evaluated patients with angiographically intermediate lesions. Using 1:1 propensity score matching (PSM) to balance baseline confounders, we established 96 matched pairs with ischemia-positive (fractional flow reserve [FFR] ≤ 0.80) and ischemia-negative (FFR > 0.80) lesions. Peak stress global work efficiency (GWE) and summed perfusion score (SPS) were assessed using multivariable logistic regression. Ischemia-positive patients exhibited significantly lower peak GWE (82.5% vs. 94.2%, p < 0.001) and higher peak SPS. Peak GWE (cut-off ≤ 89%) and peak SPS (cut-off ≥ 2) yielded areas under the curve (AUC) of 0.865 and 0.842, respectively. The combined multiparametric model achieved the highest diagnostic accuracy (AUC: 0.924), significantly improving risk reclassification (NRI: 0.615, p < 0.001) over conventional parameters. Notably, FFR-negative but stress echocardiography-positive patients displayed a higher prevalence of microvascular risk factors (female sex, diabetes, and elevated high-sensitivity C-reactive protein; all p < 0.05). The synergistic integration of dobutamine stress MW and perfusion imaging provides exceptional diagnostic accuracy for intermediate coronary lesions. This non-invasive approach serves as a robust gatekeeper for invasive testing and may capture signs of underlying microvascular dysfunction invisible to FFR.