Prognosis and risk stratification with LV global longitudinal strain and Native T1 mapping in acute myocardial infarction

Left ventricular global longitudinal strain (LV GLS) and native T1 mapping are prognostic markers after acute myocardial infarction (AMI), but the prognostic value of their combined assessment beyond established risk stratification remains uncertain. To evaluate the incremental prognostic value of combining LV GLS and native T1 mapping for major adverse cardiac events (MACE) after AMI and to assess their potential for non-contrast risk stratification. AMI patients undergoing percutaneous coronary intervention (PCI) and cardiac MRI (CMR) from four centers between February 2017 and September 2024 were retrospectively enrolled. Major adverse cardiac events (MACEs) were defined as all-cause death, life-threatening arrhythmias, cardiac death, reinfarction and heart failure hospitalization. Cox regression and Kaplan-Meier analyses were used to assess the incremental prognostic value of LV strain and native T1 mapping. A total of 1253 participants (development cohort, n = 1002; external validation cohort, n = 251) were included in the study. Over a median follow-up of 43 months, 137 and 36 participants experienced MACE in the development and external validation cohort. In the development cohort, the non-contrast Model 3 incorporating clinical variables, LVEF, native T1 z score and LV GLS improved discrimination over Model 2 incorporating conventional contrast-enhanced CMR markers (LGE, MVO and IMH) (C-index, 0.780 vs. 0.736; P = 0.033). Native T1 and LV GLS showed better prognostic performance than the GRACE and Glasgow CMR Risk Scores. The findings were validated in the external validation cohort. Combined native T1 mapping and LV GLS provided complementary prognostic information, improved risk stratification and reclassification beyond established risk factors, and supported the potential of a contrast-free CMR strategy that outperformed a conventional contrast-enhanced model.