Angiography-derived index of microcirculatory resistance as a novel tool to assess coronary microvascular dysfunction in patients with diabetic cardiomyopathy

Coronary microvascular dysfunction (CMD) has been proposed as a major mechanism and a potential therapeutic target for diabetic cardiomyopathy (DbCM); however, it has not been fully investigated in a clinical setting. The angiography-derived index of microcirculatory resistance (AMR) is a novel non-invasive measurement of CMD that exhibits promising clinical applications. AMR was measured in hospitalized patients with DbCM and in control patients. The incidence, clinical characteristics, risk factors, and effects of pharmacological interventions on CMD were investigated. AMR was significantly higher in patients who met the DbCM-2B diagnostic criteria. The independent risk factors for abnormal AMR included diabetes, body mass index (BMI), and N-terminal pro-brain natriuretic peptide (NT-pro-BNP). Patients with elevated NT-pro-BNP had high AMR, and those grouped by medication indicated that ACEI/ARB, sacubitril/valsartan, and trimetazidine might lower AMR in patients with elevated NT-pro-BNP. The DbCM-2B diagnostic criteria demonstrated a strong correlation with CMD. ACEI/ARB, sacubitril/valsartan, and trimetazidine might improve CMD in patients with DbCM.