From the Journals
Blood pressure rise follows halting CPAP
Many previous studies showed no effect of CPAP treatment on cardiovascular outcomes, but when researchers took CPAP users off therapy for 2 weeks...
Positive airway pressure, whether delivered continuously (CPAP) or as adaptive servoventilation, doesn’t reduce the rate of cardiovascular (CV) events or death in patients who have sleep apnea, according to a report published online July 11 in JAMA.
Positive airway pressure (PAP) relieves the symptoms of sleep apnea and has been reported to improve cardiovascular risk factors such as hypertension, insulin resistance, and endothelial dysfunction. However, whether the treatment improves “hard” vascular outcomes such as stroke and MI has never been established, said Jie Yu, MD, of the department of cardiology, Peking University and the Ministries of Health and Education, Beijing, and his associates.
They performed a systematic review of the literature and a meta-analysis of 10 randomized clinical trials that compared PAP against standard care or a sham treatment and had at least 6 months of follow-up for CV events. The meta-analysis involved 7,266 participants who had either obstructive (5,683 patients) or central (1,583 patients) sleep apnea. There were 356 major adverse CV events and 613 deaths during a median follow-up of 6-68 months.
The use of PAP showed no significant association with a range of outcomes: major adverse CV events (relative risk, 0.77; P = .19), major adverse CV events plus hospitalization for unstable angina (RR, 0.92; P = .54), cardiovascular death (RR, 1.15; P = .30), all-cause mortality (RR, 1.13; P = .08), noncardiovascular death (RR, 0.85; P = .33), acute coronary syndromes (RR, 1.00; P = .99), stroke (RR, 0.90; P = .47), and heart failure (RR, 1.03; P = .60). This lack of treatment benefit persisted regardless of length of follow-up, adherence to treatment, or baseline score on the apnea-hypopnea index, the investigators said (JAMA. 2017 July 11. doi: 10.1001/jama.2017.7967).
PAP also failed to improve blood pressure, body mass index, any lipid parameter, glycemia, or quality-of-life scores on the EQ-5D. It did improve sleepiness and some measures of physical and mental well-being.
“The evidence from these [randomized clinical trials] suggests that the association [between] sleep apnea and vascular outcomes and death ... may represent disease processes that cannot be ameliorated by PAP delivered at the average intensity achieved in these clinical trials or by currently feasible methods in clinical practice,” Dr. Yu and his associates said.
Their findings also “emphasize the importance of proven therapies, such as blood-pressure lowering, lipid lowering, and antiplatelet therapy, in patients with sleep apnea, who should be treated according to established guidelines for patients at elevated cardiovascular risk,” they added.
This study was supported by the National Health and Medical Research Council of Australia. Dr. Yu reported having no relevant financial disclosures. His associates reported ties to numerous industry sources.