The role of coronary angiography-derived index of microcirculatory resistance in evaluating coronary microcirculatory function and prognosis in cancer patients

Abstract Introduction The incidence of coronary artery disease is significantly increased in cancer patients. Previous studies have mostly focused on large coronary artery lesions in cancer patients, with relatively few studies on coronary microcirculation. The coronary angiography-based index of microcirculatory resistance (caIMR), as a new detection method, can be used to evaluate coronary microcirculatory function. Based on this, our study intends to explore the role of caIMR in evaluating coronary microcirculatory function and predicting prognosis in cancer patients. Purpose We intend to explore the role of caIMR in evaluating coronary microcirculatory function and prognosis in cancer patients. Methods A total of 134 cancer patients with no significant coronary artery stenosis shown by coronary angiography at our hospital were included in this study. Meanwhile, 134 non-cancer patients with no significant coronary artery stenosis were recruited as controls. The coronary microcirculatory function of enrolled patients was detected by caIMR, and coronary microcirculatory dysfunction (CMD) was defined as caIMR≥25U. The median follow-up time was 38 months. The study endpoint was major adverse cardiovascular events (MACE), including cardiac death, non-fatal myocardial infarction, heart failure, revascularization, stroke, and re-hospitalization due to angina pectoris. Results The incidence of CMD in cancer patients was higher than that in non-cancer patients (78.4% vs. 61.2%; P = 0.002), and caIMR was significantly increased in cancer patients (Figure A). During follow-up, 41 cancer patients experienced MACE. ROC curve indicated that caIMR had a good predictive value for MACE risk in cancer patients (AUC = 0.735) (Figure B), with the optimal cut-off value of 43.1U. Survival analysis showed that cancer patients with caIMR ≥ 43.1U had a higher risk of MACE (log-rank P < 0.001) (Figure C) and a higher risk of re-hospitalization due to angina pectoris (log-rank P = 0.005) (Figure D). Multivariate Cox regression analysis showed that caIMR ≥ 43.1U was an independent predictor of MACE risk in cancer patients (HR, 3.360; 95% CI, 1.610-7.012; P = 0.001). Conclusion This study found that caIMR is significantly increased in cancer patients, and elevated caIMR is an independent predictor of MACE risk in cancer patients. The optimal cut-off value of caIMR for evaluating MACE risk is 43.1U.