Increased incidence of nonfatal cardiovascular events in stroke patients with sleep apnoea: effect of CPAP treatment

Obstructive sleep apnoea (OSA) is a risk factor for stroke, but little is known about the effect of OSA and continuous positive airway pressure (CPAP) on the incidence of long-term, nonfatal cardiovascular events (CVE) in stroke patients. A prospective observational study was made in 223 patients consecutively admitted for stroke. A sleep study was performed on 166 of them. 31 had an apnoea/hypopnoea index (AHI) <10 events.h(-1); 39 had an AHI between 10 and 19 events center dot h(-1) and 96 had an AHI >= 20 events.h(-1). CPAP treatment was offered when AHI was >= 20 events. h(-1). Patients were followed up for 7 yrs and incident CVE data were recorded. The mean +/- SD age of the subjects was 73.3 +/- 11 yrs; mean AHI was 26 +/- 16.7 events.h(-1). Patients with moderate-to-severe OSA who could not tolerate CPAP (AHI >= 20 events? h(-1); n=68) showed an increased adjusted incidence of nonfatal CVE, especially new ischaemic strokes (hazard ratio 2.87, 95% CI 1.11-7.71; p=0.03), compared with patients with moderate-to-severe OSA who tolerated CPAP (n=28), patients with mild disease (AHI 10-19 events.h(-1); n=36) and patients without OSA (AHI <10 events.h(-1); n=31). Our results suggest that the presence of moderate-to-severe OSA is associated with an increased long-term incidence of nonfatal CVE in stroke patients and that CPAP reduces the excess of incidence seen in these patients.