Long-term effects of continuous positive airway pressure on blood pressure and prognosis in hypertensive patients with coronary heart disease and obstructive sleep apnea: a randomized controlled trial.

BACKGROUND Obstructive sleep apnea (OSA) can result in hypertension and significantly increase cardiovascular morbidity and mortality. There are few reports on the long-term effects of continuous positive airway pressure (CPAP) on blood pressure in patients with uncontrolled hypertension with coronary heart disease (CHD) and OSA. METHODS We conducted a prospective, long-term follow-up study in 83 patients with uncontrolled hypertension, CHD, and OSA randomized to control or CPAP groups. Daytime systolic blood pressure (SBP), diastolic blood pressure (DBP), and severe cardiovascular and cerebrovascular events (SCCEs) were recorded at baseline and follow-up. RESULTS Seventy-three patients completed the study with a median follow-up of 36 (interquartile range = 24-54) months. The 2 groups had similar characteristics at baseline. CPAP was used for 4.5 +/- 1.1 hour/night. SBP in the CPAP group was significantly reduced at follow-up (143 +/- 7 mm Hg vs. 139 +/- 7 mm Hg, P = 0.04), and SBP decreased by 8 mm Hg (95% confidence interval = 1.4-9.9; P = 0.01). Hypertension control was improved (CPAP, 69.4% for CPAP users vs. 43.2% for control subjects; P = 0.02); however, DBP did not reach statistical difference between the groups (81 +/- 10 mm Hg vs. 79 +/- 8 mm Hg; P = 0.49). In the CPAP group, the Epworth Sleepiness Scale was markedly reduced (7.0 +/- 3.4 vs. 3.7 +/- 2.3; P < 0.001). There was 1 SCCE in the CPAP group (heart failure), and 5 SCCEs in the control group (acute myocardial infarction: 2 (with 1 death); stroke: 3), but there was no significant difference identified. CONCLUSIONS Long-term CPAP application in uncontrolled hypertension with CHD and OSA significantly reduced daytime SBP, improved hypertension control and daytime sleepiness, and decreased the trend in SCCEs compared with control subjects.