Risk stratification and outcomes in diabetes mellitus patients with preserved ejection fraction: a cardiac MRI study.

Background: Patients with diabetes mellitus (DM) have a significantly increased risk of developing heart failure (HF), which exacerbates adverse cardiovascular outcomes. Limited data are available on the prognostic value of cardiac MRI in DM. We aimed to evaluate the association between MRI-derived strain analysis and adverse outcomes in DM patients at different heart failure (HF) stages.

Methods: In this prospective study, DM participants with preserved ejection fraction (EF) underwent MRI examination between January 2019 and December 2021 were evaluated. Feature tracking strain parameters were measured using cine MRI. The primary outcome was a composite outcome including HF hospitalization or cardiovascular death. Cox proportional regression was used to assess the association between risk factors and outcomes.

Results: A total of 581 DM participants (mean age, 56 years ± 13; 401 men) including 390 asymptomatic patients (stage A/B HF) and 191 heart failure with preserved EF were evaluated. After a median follow-up of 34.3 months, 74 DM patients reached the primary outcome; 13(2.2%) had cardiovascular mortality and 61(10.5%) had heart failure hospitalization. Kaplan-Meier survival curves showed that patients with global longitudinal strain (GLS) greater than or equal to -13.76% and patients with global early diastolic longitudinal strain rate (eGLSR) less than or equal to 0.51/s were more likely to experience the primary outcome (log-rank P < 0.001). In multivariable analysis, eGLSR was independently associated with an increased risk of the primary endpoint(per SD, adjusted HR: 2.038; 95% CI: 1.384-3.002; P < 0.001), but GLS was not. When risk stratification was based on GLS and eGLSR, Kaplan-Meier survival curves showed that patients with abnormal eGLSR had a significantly higher risk of adverse outcomes, regardless of GLS status. In addition, eGLSR provided incremental predictive power over clinical and imaging variables, achieving the largest C-statistic of 0.744. Of note, the association between eGLSR and outcomes was consistent in stage A/B HF patients and patients with HFpEF. Subgroup analysis showed non-ischemic LGE assessed by MRI was also independently associated with outcomes in patients with DM.

Conclusions: In DM patients with preserved ejection fraction, left ventricular eGLSR measured by cardiac MRI was an independent predictor of adverse outcomes and offered incremental prognostic value over conventional clinical and imaging indices.