A long-term follow-up study of noninvasive positive pressure ventilation on all-cause mortality in patients with chronic obstructive pulmonary disease-obstructive sleep apnea overlap syndrome

Abstract

Objective: To investigate the effect of noninvasive positive pressure ventilation(NIPPV) on all-cause mortality in patients with chronic obstructive pulmonary disease-obstructive sleep apnea overlap syndrome(OVS) through long-term follow-up. Methods: A total of 187 OVS patients were divided into the NIPPV group(n=92) and the non-NIPPV group(n=95). Of these, 85 males and 7 females were in the NIPPV group with an average age of (66.5±8.5) years(range 47-80 years); 89 males and 6 females were in the non-NIPPV group with an average age of (67.4±7.8) years(range 44-79 years). Follow-up was performed from enrolment with an average duration of 39(20, 51) months. The all-cause mortality was compared between the two groups. Result: There were no significant differences in their baseline clinical characteristics(all P>0.05), indicating that the data from the two groups were comparable. The Kaplan-Meier curve showed no difference in all-cause mortality between the two groups(log rank P=0.229). However, deaths from cardio-cerebrovascular diseases were higher in the non-NIPPV than in the NIPPV group(15.8% vs. 6.5%,P=0.045). Age, BMI, neck circumference, PaCO2, FEV1, FEV1%, moderate to severe OSA(AHI>15 events/h), mMRC, CAT, number of acute exacerbations of COPD and number of hospitalizations were associated with all-cause death in OVS patients; among which, age(HR 1.067, 95%CI 1.017-1.119, P=0.008), FEV1(HR 0.378, 95%CI 0.176-0.811, P=0.013), and number of COPD exacerbations(HR 1.298, 95%CI 1.102-1.530, P=0.002) were independent risk factors for all-cause mortality in OVS patients. Conclusions: The combination of NIPPV and conventional treatment may reduce cardio-cerebrovascular disease-related mortality in OVS patients. The deceased OVS patients had severe airflow limitation and mild to moderate OSA. Old age, low FEV1 and COPD exacerbations were independent risk factors for all-cause mortality in OVS patients.