HbA1c Independently Predicts Declined Myocardial Perfusion Reserve Index in Patients With Coronary Microvascular Disease Using Stress Perfusion Cardiac Magnetic Resonance: an Observational Study

Background We investigated whether glycated haemoglobin A1c (HbA1c) could independently predict the decline in the myocardial perfusion reserve index (MPRI) in patients with coronary microvascular disease (CMD) by stress perfusion cardiac magnetic resonance (CMR).Methods From November 2019, 174 patients with ischemic symptoms but without obstructive coronary disease were screened. The MPRI was recorded in 88 patients who underwent stress perfusion CMR detection. Eighty patients with an MPRI of < 2.5 were included in the study. The patients were divided into two groups based on whether their MPRI was greater or less than 1.47. The effects of each index on the MPRI were analysed using bivariate correlation analysis, and the risk factors for CMD were explored using logistic regression analysis.ResultsA total of 80 patients with an MPRI of 1.69±0.79 were included (mean age 54.07 ± 11.06 years; 66.3% male). CMD patients with an MPRI of ≤1.47 were higher than those in the group with an MPRI of >1.47 in age (57.61±9.65 years vs. 51.74±11.41 years), presence of diabetes mellitus (45.5% vs. 21.3%), fasting blood glucose levels [6.33(5.16, 8.01) vs. 5.30(5.15, 6.56)], and HbA1c levels [6.30(5.70, 7.70) vs. 5.80(5.60, 6.50)], (P < 0.05). The MPRI was negatively correlated with HbA1c (r=-0.378, P=0.004). Logistic regression analysis showed that HbA1c (OR=2.336, 95% CI: 1.119-4.876, P=0.024) was an independent risk factor for decreased MPRI in all patients with CMD, especially in patients without diabetes (OR=19.953, 95% CI: 1.743-93.449, P=0.029), but not in patients with diabetes (OR=0.984, 95% CI: 0.265-3.658, P=0.981).ConclusionsHbA1c is an independent predictor of MPRI decline in CMD patients, notably in CMD patients without diabetes, but not for those with diabetes.Trial RegistrationThis clinical trial has been registered in the Chinese clinical Trial Registry with an identifier: ChiCTR1900025810.

Temporal Trends in Angina, Myocardial Perfusion, and Left Ventricular Remodeling in Women With No Obstructive Coronary Artery Disease Over 1‐Year Follow‐Up: Results From WISE‐CVD

Background Women with ischemia and no obstructive coronary artery disease are increasingly recognized and found to be at risk for major adverse cardiovascular events. Methods and Results In 214 women with suspected ischemia and no obstructive coronary artery disease who completed baseline and 1‐year follow‐up vasodilatory stress cardiac magnetic resonance imaging, we investigated temporal trends in angina (Seattle Angina Questionnaire [SAQ]), myocardial perfusion reserve index, blood pressure, and left ventricular (LV) remodeling and function from baseline to 1‐year follow‐up and explored associations between these different parameters. We observed concordant positive trends in 4/5 SAQ domains, SAQ‐7, myocardial perfusion reserve index, blood pressure, LV mass, and LV mass‐to‐volume ratio. There was no association between SAQ‐7 improvement and myocardial perfusion reserve index improvement over 1‐year follow‐up ( P =0.1). Higher indexed LV end‐diastolic volume and time to peak filling rate at baseline were associated with increased odds of clinically relevant SAQ‐7 improvement (odds ratio [OR], 1.05; 95% CI, 1.0–1.1; and OR, 2.40; 95% CI, 1.1–5.0, respectively). Hypertension was associated with decreased odds of SAQ‐7 improvement (OR, 0.41; 95% CI, 0.19–0.91). Conclusions In women with ischemia and no obstructive coronary artery disease clinically treated with cardiac medications over 1 year, we observed concurrent temporal trends toward improvement in SAQ, myocardial perfusion reserve index, blood pressure, LV mass, and LV mass‐to volume ratio. We showed that abnormalities in LV morphology and diastolic function at baseline were predictive of clinically significant improvement in angina at follow‐up, whereas history of hypertension was associated with lower odds. Future studies are needed to assess the mechanisms and treatments responsible for the improvements we observed. Registration URL: https://www.clini​caltr​ials.gov ; Unique identifier: NCT02582021.