Effect of Continuous Positive Airway Pressure on the Incidence of Hypertension and Cardiovascular Eventsin Nonsleepy Patients With Obstructive Sleep Apnea

Context Continuous positive airway pressure (CPAP) is the first-line treatment for patients
with symptomatic obstructive sleep apnea (OSA). However, its indication for all
patients with sleep-disordered breathing, regardless of daytime symptoms, is unclear.
Objective To evaluate the effect of CPAP treatment on the incidence of hypertension
or cardiovascular events in a cohort of nonsleepy patients with OSA.
Design, Setting, and Patients Multicenter, parallel-group, randomized controlled
trial in 14 teaching hospitals in Spain. Between May 2004 and May 2006, 725
consecutive patients were enrolled who had an apnea-hypopnea index of 20 h−1 or
greater and an Epworth Sleepiness Scale score of 10 or less (scores range from 0-24,
with values 10 suggesting no daytime sleepiness). Exclusion criteria were previous
cardiovascular event, physical or psychological incapacity, chronic disease, or drug or
alcohol addiction. Follow-up ended in May 2009.
Intervention Patients were allocated to receive CPAP treatment or no active intervention.
All participants received dietary counseling and sleep hygiene advice.
Main Outcome Measures Incidence of either systemic hypertension (taking antihypertensive
medication or blood pressure greater than 140/90 mm Hg) or cardiovascular
event (nonfatal myocardial infarction, nonfatal stroke, transient ischemic attack,
hospitalization for unstable angina or arrhythmia, heart failure, or cardiovascular death).
Results Seven hundred twenty-three patients underwent follow-up for a median of 4
(interquartile range, 2.7-4.4) years (1 patient from each group did not receive allocated
treatment); 357 in the CPAP group and 366 in the control group were included in the
analysis. In the CPAP group there were 68 patients with new hypertension and 28 cardiovascular
events (17 unstable angina or arrhythmia, 3 nonfatal stroke, 3 heart failure,
2 nonfatal myocardial infarction, 2 transient ischemic attack, 1 cardiovascular death). In
the control group there were 79 patients with new hypertension and 31 cardiovascular
events (11 unstable angina or arrhythmia, 8 nonfatal myocardial infarction, 5 transient
ischemic attack, 5 heart failure, 2 nonfatal stroke). The hypertension or cardiovascular
event incidence density rate was 9.20 per 100 person-years (95% CI, 7.36-11.04) in
the CPAP group and 11.02 per 100 person-years (95% CI, 8.96-13.08) in the control
group. The incidence density ratio was 0.83 (95% CI, 0.63-1.1; P=.20).
Conclusions In patients with OSA without daytime sleepiness, the prescription of
CPAP compared with usual care did not result in a statistically significant reduction in
the incidence of hypertension or cardiovascular events. However, the study may have
had limited power to detect a significant difference.This study was funded by the Instituto de Salud Carlos III (PI 04/0165) (Fondo de Investigaciones Sanitarios, Ministerio de Sanidad y Consumo, Spain), Spanish Respiratory Society (SEPAR) (Barcelona), Resmed (Bella Vista, Australia), Air Products–Carburos Metalicos (Barcelona), Respironics (Murrysville, Pennsylvania), and Breas Medical (Madrid, Spain)