Efficacy of continuous positive airway pressure treatment on 5-year survival in patients with ischaemic stroke and obstructive sleep apnea: a randomized controlled trial.

The main purpose of the present analysis is to assess the influence of introducing early nasal continuous positive airway pressure (nCPAP) treatment on cardiovascular recurrences and mortality in patients with a first-ever ischaemic stroke and moderate-severe obstructive sleep apnea (OSA) with an apnea-hypopnea index (AHI) ≥20 events h(-1) during a 5-year follow-up. Patients received conventional treatment for stroke and were assigned randomly to the nCPAP group (n = 71) or the control group (n = 69). Cardiovascular events and mortality were registered for all patients. Survival and cardiovascular event-free survival analysis were performed after 5-year follow-up using the Kaplan-Meier test. Patients in the nCPAP group had significantly higher cardiovascular survival than the control group (100 versus 89.9%, log-rank test 5.887; P = 0.015) However, and also despite a positive tendency, there were no significant differences in the cardiovascular event-free survival at 68 months between the nCPAP and control groups (89.5 versus 75.4%, log-rank test 3.565; P = 0.059). Early nCPAP therapy has a positive effect on long-term survival in ischaemic stroke patients and moderate-severe OSA.

Long-term effect of continuous positive airway pressure on BP in patients with hypertension and sleep apnea.

OBJECTIVE: To analyze the long-term effect of continuous positive airway pressure (CPAP) on ambulatory BP in patients with obstructive sleep apnea (OSA) and hypertension, and to identify subgroups of patients for whom CPAP could be more effective. METHODS: We conducted a prospective, long-term follow-up trial (24 months) in 55 patients with OSA and hypertension (mean CPAP use, 5.3 +/- 1.9 h/d [+/- SD]). Twenty-four-hour ambulatory BP monitoring (ABPM) was measured at baseline and after intervention with CPAP on an intention-to-treat basis. In addition, the correlation between the changes in 24-h mean arterial pressure (24hMAP) and CPAP compliance, OSA severity, and baseline ABPM was assessed. RESULTS: At the end of follow-up, a significant decrease was shown only in diastolic BP (- 2.2 mm Hg; 95% confidence interval [CI], - 4.2 to - 0.1; p = 0.03) but not in 24hMAP or other ABPM parameters. However, a correlation between changes in 24hMAP and baseline systolic BP (r = - 0.43, p = 0.001), diastolic BP (r = - 0.38, p = 0.004), and hours of use of CPAP (r = - 0.30, p = 0.02) was observed. A significant decrease in the 24hMAP was achieved in a subgroup of patients with incompletely controlled hypertension at entry (- 4.4 mm Hg; 95% CI, - 7.9 to - 0.9 mm Hg; p = 0.01), as well as in those with CPAP compliance > 5.3 h/d (- 5.3 mm Hg; 95% CI, - 9.5 to - 1.2 mm Hg; p = 0.01). Linear regression analysis showed that baseline systolic BP and hours of CPAP were independent predictors of reductions in BP with CPAP. CONCLUSION: Long-term CPAP reduced BP modestly in the whole sample. However, patients with higher BP at entry and good CPAP compliance achieved significant reductions in BP.

Effect of continuous positive airway pressure on ambulatory BP in patients with sleep apnea and hypertension: a placebo-controlled trial.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for arterial hypertension. Several controlled trials have investigated the effect of continuous positive airway pressure (CPAP) on BP in patients with OSAS, but its effect on hypertensive patients has not been analyzed specifically. OBJECTIVE: To analyze the effect of CPAP on ambulatory BP in patients with OSAS and hypertension who were undergoing antihypertensive treatment. DESIGN AND PATIENTS: We conducted a parallel, randomized, placebo-controlled trial in 68 patients with OSAS and hypertension, who were receiving treatment with antihypertensive medication. Patients were randomly allocated to either therapeutic or subtherapeutic CPAP for 4 weeks. Ambulatory BP was registered at baseline and after treatment. Antihypertensive treatment was not changed during the study. Changes in BP were assessed on an intention-to-treat basis. RESULTS: There were no baseline differences in the apnea-hypopnea index, comorbidities, or ambulatory BP between groups. Objective compliance with CPAP was similar in both the therapeutic and subtherapeutic groups (5.0 +/- 1.4 h/d vs 4.4 +/- 1.9 h/d, respectively; p = 0.13 [mean +/- SD]). There was a small and statistically nonsignificant decrease (- 0.3 +/- 6.3 mm Hg vs - 1.1 +/- 7.9 mm Hg; difference, - 0.8 mm Hg [95% confidence interval, - 2.7 to 4.3]; p = 0.65) in 24-h mean BP (24hMBP) in both subtherapeutic and therapeutic groups after 4 weeks of treatment. No significant changes in systolic, diastolic, daytime, or nighttime BP were observed. The normal circadian dipper pattern was restored in a higher proportion of patients in the therapeutic group compared to the subtherapeutic CPAP group, although differences were not significant (11 of 32 patients vs 3 of 25 patients; odds ratio, 3.84; 95% confidence interval, 0.82 to 20.30; p = 0.10). There was no correlation between the magnitude of change in 24hMBP and CPAP compliance, OSAS severity, or number of antihypertensive drugs used. CONCLUSION: Four weeks of CPAP did not reduce BP in patients with OSAS and hypertension who were treated with antihypertensive medication, compared to placebo group.

Mortality in obstructive sleep apnea-hypopnea patients treated with positive airway pressure.

STUDY OBJECTIVES: The aims of this study were to analyze mortality in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) treated with positive airway pressure (PAP) and to know whether PAP compliance affects survival, as well as to investigate the prognostic value of several pretreatment variables. DESIGN AND PATIENTS: A study was made of an historical cohort of 871 patients in whom OSAHS had been diagnosed by sleep study between January 1994 and December 2000 and who had been treated with PAP. Patients were followed up until December 2001. The mean (+/- SD) age of the group was 55.4 +/- 10.6 years, the mean apnea-hypopnea index (AHI) 55.1 +/- 28.7, and 80.9% were men. To assess whether mortality was influenced by PAP therapy compliance, patients were assigned to one of the following compliance categories: < 1 h/d; 1 to 6 h/d; or > 6 h/d. Survival rates were calculated according to the Kaplan-Meier method. Survival curves were compared with the log-rank test and the trend test, when necessary. Univariate and multivariate analyses using a time-dependent Cox model were performed to elicit which variables correlated with mortality. SETTING: Outpatient sleep disorders unit. RESULTS: By the end of the follow-up period (mean duration, 48.5 +/- 22.7 months), 46 patients had died. The 5-year cumulative survival rates were significantly lower in patients who did not use PAP (compliance < 1 h) than in those who used the device for > 6 h/d (85.5% [95% confidence interval (CI), 0.78 to 0.92] vs 96.4% [95% CI, 0.94 to 0.98; p < 0.00005]) and 1 to 6 h/d (85.5% [95% CI, 0.78 to 0.92] vs 91.3% [ 95% CI, 0.88 to 0.94; p = 0.01]), respectively. A trend in survival rates across the groups was identified (p = 0.0004). The main cause of death in 19 cases was cardiovascular disease (CVD). Variables that independently correlated with mortality in the multivariate analysis were the following PAP use categories: compliance for > 6 h/d (odds ratio [OR], 0.10; 95% CI, 0.04 to 0.29); compliance for 1 to 6 h/d (OR, 0.28; 95% CI, 0.11 to 0.69); arterial hypertension (AHT) [OR, 3.25; 95% CI, 1.24 to 8.54]; age (OR, 1.06; 95% CI, 1.01 to 1.10); and FEV1 percent predicted (OR, 0.96; 95% CI, 0.94 to 0.98). CONCLUSION: Mortality rates in OSAHS patients who did not receive PAP therapy were higher compared with those treated with PAP and were moderately or highly compliant with therapy. A trend in survival across compliance categories was found. Patients died mainly from CVD. Categories of PAP compliance, AHT, age, and FEV1 percent predicted were the variables that independently predicted mortality.