Coronary microvascular dysfunction and myocardial area at risk assessed by CZT-SPECT after primary PCI in AMI patients

Abstract

Abstract Purpose This study used CZT-SPECT to evaluate the prevalence and characteristics of coronary microvascular dysfunction (CMD) and myocardial area at risk (AAR) in acute myocardial infarction (AMI) patients who received primary percutaneous coronary intervention (PCI). Methods This was a single-center cross-sectional retrospective study. 83 patients received primary PCI for acute myocardial infarction. Subsequently, a rest/stress dynamic and routine gated myocardial perfusion imaging one week after PCI. The CMD group was defined as: the residual stenosis of infarct-related artery (IRA) < 50% and myocardial Flow Reserve (MFR) < 2.0 in this corresponding territory; While MFR ≥ 2.0 of IRA pertained to the normal control group. Results A total of 53 patients with a mean age of 57.06 ± 11.99 years were recruited, of whom 81.1% were STEMI. The proportion of patients with CMD was 79.2% (42/53). The time of pain to SPECT imaging was 7.50 ± 1.27 days in CMD group and 7.45 ± 1.86 days in controls. CMD patients had a higher body mass index (BMI) than controls (26.48 ± 3.26 vs 24.36 ± 2.73, P < 0.05), and a higher proportion of STEMI, TIMI 0 grade of infarct relate artery (IRA) prior PCI than controls (88.1% vs 54.5%, 61.9% vs 18.2% respectively) (all P < 0.05). No significant difference was identified in the rest-myocardial blood flow (MBF) of IRA between the two groups, whereas the stress-MBF and MFR of IRA, Rest-AAR, Stress-AAR in the CMD group were remarkably lowered (P < 0.01). Higher BMI (OR:1.332, 95%CI:1.008–1.760) and Stress-AAR (OR:1.994, 95%CI:1.122–3.543) were used as independent predictors of CMD occurrence (P < 0.05). Conclusions The prevalence of CMD is high in AMI patients who received primary PCI. Each 1kg/m2 increase in BMI was associated with a 1.3-fold increase in CMD risk. A 5% increase in Stress-AAR was associated with a nearly 2-fold increase in CMD risk. Increased BMI and stress-AAR predicts decreased coronary reserve function.