Glycemic Status and Myocardial Strain by Cardiac MRI in Patients With ST‐Segment Elevation Myocardial Infarction

Abstract

BackgroundIt is uncertain how various degree of glycemic status affect left ventricular (LV) myocardial strain in ST‐segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI).PurposeTo investigate the relationship of glycemic status and myocardial strain in STEMI patients.Study TypeProspective cohort study.Population282 STEMI patients with cardiac magnetic resonance imaging 5 ± 2 days post‐PPCI. Patients were divided into three groups based on the level of glycated hemoglobin A1c (HbA1c) (group 1: HbA1c < 5.7%; group 2: 5.7% ≤ HbA1c < 6.5%; group 3: HbA1c ≥ 6.5%).Field Strength/Sequence3.0‐T; late gadolinium enhancement, balanced steady‐state free precession cine sequence, black blood fat‐suppressed T2‐weighted.AssessmentLV function, myocardial strain, and infarct characteristics (infarct size, microvascular obstruction, and intramyocardial hemorrhage) were compared among the three groups by one‐way analysis of variance (ANOVA) or Wilcoxon rank sum test. Intraobserver and interobserver reproducibility of LV myocardial strain was evaluated.Statistical TestsANOVA or Wilcoxon rank sum test, Pearson chi‐square or Fisher's exact test, Spearman's correlation analyses and multivariable linear regression analysis. A two‐tailed P value <0.05 was considered statistically significant.ResultsInfarct characteristics were similar among the three groups (P = 0.934, P = 0.097, P = 0.533, respectively). Patients with HbA1c ≥ 6.5% had decreased LV myocardial strain compared with HbA1c 5.7%–6.4%, as evidenced by global radial (GRS), global circumferential (GCS), and global longitudinal (GLS) strain. However, no significant differences in myocardial strain were observed between patients with HbA1c 5.7%–6.4% and HbA1c < 5.7% (P = 0.716; P = 0.294; P = 0.883, respectively). After adjustment for confounders, HbA1c as a continuous variable (beta coefficient [β] = −0.676; β = 0.172; β = 0.205, respectively) and HbA1c ≥ 6.5% (β = −3.682; β = 0.552; β = 0.681, respectively) were both independently associated with decreased GRS, GCS, and GLS.Data ConclusionPatients with uncontrolled blood glucose (categorized in group HbA1c ≥ 6.5%) had worse myocardial strain. The level of HbA1c appeared to be independently associated with decreased myocardial strain in STEMI patients.Level of Evidence2Technical Efficacy Stage2