Cardiovascular problems can be associated with sleep apnea, and it's commonly assumed that treatment of sleep apnea could have cardiovascular benefits. But a ResMed ($RMD) study found that its sleep apnea Adaptive Servo-Ventilation (ASV) treatment could actually worsen cardiovascular mortality and is ill-advised for a specific subset of patients.
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| ResMed CEO Michael Farrell |
The company designed the SERVE-HF trial to assess whether its ASV therapy reduced mortality and morbidity in patients with symptomatic chronic heart failure when used as an addition to optimal medical care.
Instead, the study found that the cardiovascular mortality rate in the ASV group was 10% a year, compared to only 7.5% a year in the control group. The company confirmed that the ASV therapy devices were performing correctly during the trial. In a prior study of central sleep apnea patients, 90% experienced relief at 90-days compared to about two-thirds on a standard CPAP machine.
"The safety signal in SERVE-HF was observed only with the use of ASV therapy in people who have predominant central sleep apnea and symptomatic chronic heart failure with reduced ejection fraction. We are further analyzing the data to understand why this unexpected result was observed in this trial," said ResMed CMO Dr. Glenn Richards in a statement.
The company said it is already working with global regulatory authorities regarding the safety signal seen in the study. Specifically, it is working to revise the labels and instructions for ResMed ASV devices to include a contraindication for people with symptomatic chronic heart failure with left ventricular ejection fraction of less than or equal to 45%.
"SERVE-HF did not meet its primary endpoint, however this study provides valuable, practice-changing guidance on how to best care for people with chronic heart failure," said Dr. Martin Cowie, the co-principal investigator of the study and professor of cardiology at Imperial College in London, said in a statement.
He added that because of this trial, "we now know that ASV therapy should not be used to treat central sleep apnea in people with symptomatic chronic heart failure with reduced ejection fraction."
ResMed is also conducting the CAT-HF trial for its ASV therapy. The 215-person trial in acute decompensated heart failure is measuring a primary endpoint based on survival without cardiovascular hospitalization and improvement on the 6-minute walk test at 6 months versus baseline. Data from the trial are expected in 2017.
"As a reminder, SERVE-HF is powered to show changes in mortality and morbidity in heart failure patients with CSA, while CAT-HF is powered show improvements in global cardiovascular outcomes. Both trials lead to a potential change in guiding principles and standard-of-care for heart failure patients," ResMed CEO Michael Farrell said on an April earnings call.
Investors pushed ResMed down 15% in early trading on the news, giving it a market cap of $7.8 billion.
- here is the release