Is survival in Myotonic Dystrophy improved by chronic ventilatory support?

Abstract

Background: Home mechanical ventilation (HMV) is a questionable treatment in patients with myotonic dystrophy type 1 (DM1), due to a presumed poor adherence, minor symptomatic improvement and uncertainty regarding a survival benefit. We aimed to investigate indications, adherence and survival related to HMV in a relatively large cohort of DM1 patients. Methods: In this retrospective study we evaluated 234 DM1 patients who visited the HMV centre of the University Medical Centre Utrecht between 1996 and 2018. We collected results of pulmonary function test, indications for and compliance with HMV, and survival data. To analyse the effect of HMV on survival a cox regression analysis was used. Results: In total 234 patients were analysed of whom 118 started HMV. In 13 patients ventilation was started in an acute setting. Other patients started electively because of daytime (n=72) or nocturnal hypercapnia (n=33). Adequate adherence (≥ 4 hours per night) was found in 99 patients (84%). In 34 patients (28%) ventilatory support was stopped prematurely due to as patients’ expectations were not reached (n=22), or due to intolerance in eight patients, or other reasons (n=4). HMV did not improve survival, even not in patients with hypercapnia at daytime (p=0.64). The analyses was corrected for age and vital capacity. Conclusion: Home mechanical ventilation in DM1 patients is tolerated well in most patients with a reliable adherence. Survival was not improved by mechanical ventilation, even not in patients with daytime hypercapnia. Further research is needed to identify whether a subgroup of DM1 patients exists who benefit from HMV.