Cardiac MR Characterization of Infarct‐Related and Remote Myocardial Injury in Multivessel Disease After Acute Myocardial Infarction

BACKGROUND: Patients with multivessel disease (MVD) after acute myocardial infarction (AMI) have worse outcomes than those with single-vessel disease (SVD), but whether MVD is associated with diffuse myocardial injury beyond the infarct zone (IZ) remains unclear. PURPOSE: To characterize infarct-related and remote myocardial tissue properties using cardiac MRI in patients with MVD compared with SVD after AMI, and to explore differences according to revascularization completeness. STUDY TYPE: Retrospective. POPULATION: Two hundred and twenty-four patients with AMI who underwent MRI within 31-90 days after percutaneous coronary intervention (90 SVD, 42 MVD with complete revascularization [CR], and 92 MVD with incomplete revascularization [IR]). FIELD STRENGTH/SEQUENCES: 3.0 T; balanced steady-state free precession cine, phase-sensitive inversion recovery late gadolinium enhancement (LGE), modified Look-Locker (pre- and post-contrast T1-mapping), and gradient and spin echo (T2-mapping) sequences. ASSESSMENT: Left ventricular volumes and function (cine), infarct size (LGE), and myocardial tissue parameters (native T1 and extracellular volume [ECV], and T2) were quantified in IZ, peri-infarct zone (PIZ), and remote zone (RZ) using standardized methods. STATISTICAL TESTS: or Fisher exact test for categorical variables. Adjusted comparisons of myocardial tissue parameters between coronary disease groups were performed using multivariable logistic regression models including relevant clinical covariates and infarct size. A p value < 0.05 was considered significant. RESULTS: Compared with SVD, MVD showed larger infarct size (p < 0.001), and higher native T1, ECV, and T2 values in PIZ (p = 0.034, 0.004, 0.005) and RZ (p = 0.041, < 0.001, < 0.001). After adjustment for clinical covariates (age, diabetes, hyperlipidemia, BMI) and infarct size, these differences in RZ remained significant. Among patients with MVD, infarct size and ventricular function did not differ between CR and IR groups (p = 0.661, 0.494, 0.857). However, MVD-IR was associated with significantly higher ECV-PIZ (p = 0.023), ECV-RZ (p = 0.025) and T2-RZ (p = 0.003). DATA CONCLUSIONS: In AMI, MVD was associated with diffuse myocardial injury extending beyond the IZ. Differences related to revascularization completeness predominantly involved non-infarct myocardium. TECHNICAL EFFICACY: Stage 2.