Patients with late-stage Duchenne muscular dystrophy (DMD) with reduced (≤40%) left ventricular ejection fraction (LVEF) have worse clinical outcomes, according to a new study published in ESC Heart Failure.
The study also found that increased levels of brain-natriuretic protein (BNP) and the use of diuretics were significant predictors of adverse clinical outcomes independent of LVEF.
“As expected, patients with DMD and systolic dysfunction had higher mortality and more cardiovascular events than those without systolic dysfunction,” the authors said. “However, in the multivariate analysis, diuretic use and BNP level rather than reduced [left ventricular] systolic function were independent predictors of survival and cardiovascular events.”
The primary endpoint of the study was all-cause death with a secondary endpoint being a composite event comprised of death or unexpected hospitalization due to cardiovascular events such as chest pain, dyspnea, and generalized edema.
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For the primary endpoint, patients with reduced LVEF (≤40%) showed a lower rate of 6-year overall survival compared to patients who maintained an LVEF >40% (81.3% vs 98.8%; P =.005). Using multivariate Cox regression analysis, significant predictors of the primary endpoint included BNP levels (hazard ratio [HR], 1.088; 95% CI, 1.019-1.162) and the use of diuretics (HR, 9.279; 95% CI, 1.651-52.148).
In regards to the secondary endpoint, patients with reduced LVEF had a lower percentage of patients who were free from the composite event than the maintained LVEF group (65.6% vs 86.9%). In multivariate regression analysis, however, LVEF was not an independent predictor of the composite events. BNP levels and the use of diuretics were both still significant predictors of the secondary endpoint with adjusted HRs of 1.057 (P =.032) and 4.189 (P =.002), respectively.
A total of 116 late-stage (age >15 years) patients with DMD were enrolled in the retrospective study and divided into the reduced LVEF group (n=32) and the preserved LVEF group (n=84). The average age of patients was 20.8 years with a total disease duration of 18.8 years. There were no significant differences between the groups in terms of disease duration, age, body mass index, nonambulatory phase rate, or corticosteroid use.
Cha JJ, Kim IS, Kim JY, et al. The association between cardiac involvement and long-term clinical outcomes in patients with Duchenne muscular dystrophy. ESC Heart Fail. Published online May 17, 2022. doi:10.1002/ehf2.13970