Spinal muscular atrophy type 1: are proactive respiratory interventions associated with longer survival?

CONTEXT: Spinal muscular atrophy type 1, an autosomal recessive motor neuron disease, is a leading genetic cause of death in infancy and early childhood.

OBJECTIVE: To determine whether the early initiation of noninvasive respiratory interventions is associated with longer survival.

DESIGN: Single-institution retrospective cohort study identified children with spinal muscular atrophy type 1 from January 1, 2002 to May 1, 2009 who were followed for 2.3 mean yrs.

SETTING: Tertiary care children's hospital and outpatient clinics in a vertically integrated healthcare system.

PATIENTS OR OTHER PARTICIPANTS: Forty-nine children with spinal muscular atrophy type 1 were grouped according to the level of respiratory support their caregivers chose within the first 3 months after diagnosis: proactive respiratory care (n = 26) and supportive care (n = 23).

INTERVENTIONS: Proactive respiratory care included bilevel noninvasive ventilation during sleep and twice a day cough assist while supportive respiratory care included suctioning, with or without supplemental oxygen.

MEASUREMENTS AND MAIN RESULTS: Kaplan-Meier survival curves were assessed based on intention to treat. Children treated with early proactive respiratory support had statistically longer survival compared to supportive care (log rank 0.047); however, the adjusted hazard ratio for survival was not statistically different (2.44 [95% confidence interval 0.84-7.1]). Children in the proactive group were more likely to be hospitalized for respiratory insufficiency (83% vs. 46%) and had shortened time after diagnosis until first hospital admission for respiratory insufficiency (median 118 vs. 979 days).

CONCLUSION: Longer survival time with spinal muscular atrophy type 1 is associated with early, noninvasive respiratory care interventions after diagnosis.