Microcirculatory resistance based on a single angiographic view in ST-segment elevation myocardial infarction patients.

Background: Angio-based microvascular resistance (AMR) was proposed as a tool to quantitatively assess coronary microvascular based on single angiographic projection. The aims of this study are to assess the diagnostic accuracy and prognostic significance of AMR in ST-segment elevation myocardial infarction (STEMI) patients.

Methods: AMR was measured (Of these, 22 patients measured index of microvascular resistance (IMR)) in 70 STEMI patients after primary percutaneous coronary intervention (pPCI). ST-segment resolution (STR) was assessed 2 h after pPCI simultaneously. Transthoracic echocardiography was performed within 1 day and approximately 1 year after pPCI. STEMI patients underwent pPCI were followed up for 7.3 years and the primary endpoint was the major adverse cardiac and cerebral events (MACCEs).

Results: AMR showed significant correlations with IMR (R = 0.334, P = 0.005). AMR has good predictive power for STR after pPCI (area under the curve: 0.889, sensitivity: 94.59%, specificity: 75.76%) in receiver operating characteristic (ROC) curve. Low-AMR patients showed markedly improved left ventricular ejection fraction (LVEF) 1 year after pPCI (42(40-49) vs. 41(39-44), P = 0.041). High-AMR patients showed higher risk for MACCEs than those with Low-AMR (HR = 3.90, P = 0.02). In multivariate cox regression analysis, AMR was considered an independent predictor of MACCEs (HR: 1.153, P = 0.020).

Conclusions: AMR is a reliable tool for the estimation of microvascular resistance and prognosis in the absence of intracoronary pressure-temperature sensor wire and adenosine based on single angiographic projection.