[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, PaCO_2, 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.