Patients with untreated, moderate to severe obstructive sleep apnea who underwent percutaneous coronary intervention were more than twice as likely to undergo repeat revascularization during the next 4.8 years, compared with patients on continuous positive airway pressure (CPAP), researchers reported in the March issue of Chest.
The first-in-kind finding “provides new evidence that untreated moderate-severe OSA [obstructive sleep apnea] is an independent risk factor for repeat revascularization after PCI [percutaneous coronary intervention] and that CPAP can reduce this risk.,” said Dr. Xiaofan Wu at the Beijing Anzhen Hospital at Capital Medical University in Beijing and her associates. “Interestingly, the data show that untreated mild OSA was not associated with an increased risk of repeat revascularization, suggesting a dose-effect relationship between OSA severity and risk of complications after PCI.”
Untreated OSA has been linked with many cardiovascular problems. Patients have high levels of sympathetic excitation, oxidative stress, inflammatory mediators, endothelial dysfunction, and attenuated endothelial repair, which all can promote atherogenesis, hypertension, arrhythmogenesis, and cardiac death, the researchers noted. But the effect of untreated OSA on PCI outcomes was not well understood, they said ( Chest 2015;147:708-18 ).
Their study retrospectively followed 390 patients with OSA who had undergone PCI. The cohorts included 128 patients with moderate to severe OSA that was successfully treated with CPAP, 167 patients with untreated, moderate to severe OSA, and 95 patients with untreated mild OSA. The investigators used subjective patient reports to assess adherence to CPAP. In all, 83.6% of treated patients had used CPAP for at least 6 months, and the rest had used CPAP for 3-6 months, they said.
Over a median follow-up of 4.8 years, 25.1% of patients with untreated, moderate to severe OSA underwent repeat revascularization, compared with 14.1% of patients on CPAP for similarly severe OSA (P = .019), the investigators reported. In the adjusted analysis, untreated patients had more than double the likelihood of repeat revascularization during the follow-up period (hazard ratio, 2.13; 95% confidence interval, 1.19-3.81; P = .011).
Mortality and rates of major adverse cardiac and cerebrovascular events were similar among the groups, said the researchers. “Although untreated moderate to severe OSA was not associated with an increased risk of death in this cohort, we believe that timely diagnosis and treatment in patients undergoing PCI can serve as a clinically relevant method of secondary prevention to decrease the risk of repeat revascularization,” they said.
The work was funded by the Program for New Century Excellent Talents in University from the Ministry of Education of China, National Natural Science Foundation of China, the Capital Health Research and Development Fund of China, and National Institutes of Health. One coauthor reported relationships with Koninklijke Philips NV and Philips/Respironics. The other authors declared no relevant conflicts of interest.