Initiation of non-invasive positive pressure ventilation did not significantly change the estimated 1.6% per year rate of decline in left ventricular ejection fraction in patients with Duchenne muscular dystrophy.
Cohort (n=890)
Yes
Does non-invasive positive pressure ventilation prevent the progression of left ventricular dysfunction in males with Duchenne muscular dystrophy?
In patients with Duchenne muscular dystrophy, left ventricular ejection fraction declines by approximately 1.6% per year, a rate that is not altered by the initiation of non-invasive positive pressure ventilation.
p-value: p=0.60
BACKGROUND: Duchenne muscular dystrophy is associated with progressive cardiorespiratory failure, including left ventricular dysfunction. METHODS AND RESULTS: Males with probable or definite diagnosis of Duchenne muscular dystrophy, diagnosed between 1 January, 1982 and 31 December, 2011, were identified from the Muscular Dystrophy Surveillance Tracking and Research Network database. Two non-mutually exclusive groups were created: patients with ≥2 echocardiograms and non-invasive positive pressure ventilation-compliant patients with ≥1 recorded ejection fraction. Quantitative left ventricular dysfunction was defined as an ejection fraction <55%. Qualitative dysfunction was defined as mild, moderate, or severe. Progression of quantitative left ventricular dysfunction was modelled as a continuous time-varying outcome. Change in qualitative left ventricle function was assessed by the percentage of patients within each category at each age. Forty-one percent (n = 403) had ≥2 ejection fractions containing 998 qualitative assessments with a mean age at first echo of 10.8 ± 4.6 years, with an average first ejection fraction of 63.1 ± 12.6%. Mean age at first echo with an ejection fraction <55 was 15.2 ± 3.9 years. Thirty-five percent (140/403) were non-invasive positive pressure ventilation-compliant and had ejection fraction information. The estimated rate of decline in ejection fraction from first ejection fraction was 1.6% per year and initiation of non-invasive positive pressure ventilation did not change this rate. CONCLUSIONS: In our cohort, we observed that left ventricle function in patients with Duchenne muscular dystrophy declined over time, independent of non-invasive positive pressure ventilation use. Future studies are needed to examine the impact of respiratory support on cardiac function.
James et al. (Wed,) conducted a cohort in Duchenne muscular dystrophy (n=890). Non-invasive positive pressure ventilation vs. Prior to non-invasive positive pressure ventilation initiation (within-patient comparison) was evaluated on Change in the rate of decline of left ventricular ejection fraction (p=0.60). Initiation of non-invasive positive pressure ventilation did not significantly change the estimated 1.6% per year rate of decline in left ventricular ejection fraction in patients with Duchenne muscular dystrophy.