Abstract

Aims To assess whether left ventricular (LV) global longitudinal strain (GLS), derived from cardiovascular magnetic resonance (CMR), is associated with (i) progressive heart failure (HF), and (ii) sudden cardiac death (SCD) in patients with dilated cardiomyopathy with mildly reduced ejection fraction (DCMmrEF). Methods and results We conducted a prospective observational cohort study of patients with DCM and LV ejection fraction (LVEF) ≥40% assessed by CMR, including feature‐tracking to assess LV GLS and late gadolinium enhancement (LGE). Long‐term adjudicated follow‐up included (i) HF hospitalization, LV assist device implantation or HF death, and (ii) SCD or aborted SCD (aSCD). Of 355 patients with DCMmrEF (median age 54 years [interquartile range 43–64], 216 men [60.8%], median LVEF 49% [46–54]) followed up for a median 7.8 years (5.2–9.4), 32 patients (9%) experienced HF events and 19 (5%) died suddenly or experienced aSCD. LV GLS was associated with HF events in a multivariable model when considered as either a continuous (per % hazard ratio [HR] 1.10, 95% confidence interval [CI] 1.00–1.21, p = 0.045) or dichotomized variable (LV GLS > −15.4%: HR 2.70, 95% CI 1.30–5.94, p = 0.008). LGE presence was not associated with HF events (HR 1.49, 95% CI 0.73–3.01, p = 0.270). Conversely, LV GLS was not associated with SCD/aSCD (per % HR 1.07, 95% CI 0.95–1.22, p = 0.257), whereas LGE presence was (HR 3.58, 95% CI 1.39–9.23, p = 0.008). LVEF was neither associated with HF events nor SCD/aSCD. Conclusion Multi‐parametric CMR has utility for precision prognostic stratification of patients with DCMmrEF. LV GLS stratifies risk of progressive HF, while LGE stratifies SCD risk.