Abstract
Background
Obstructive sleep apnoea (OSA) is a risk factor for hypertension and associated with increased cardiovascular risk. Continuous positive airway pressure (CPAP) is presumed to be an everyday therapy and has been shown to reduce blood pressure and improve other measures of vascular risk. It is not known whether short-term CPAP withdrawal results in impaired myocardial perfusion and thus, might increase the risk for myocardial ischemia.
Objective
We assessed the effect of a short-term CPAP withdrawal on myocardial perfusion in patients with OSA.
Methods
45 patients with moderate to severe OSA, currently on CPAP, were randomised to either continue or withdraw CPAP (subtherapeutic CPAP) for two weeks. Sleep studies and cardiac positron emission tomography to assess myocardial perfusion were performed at baseline and at two weeks.
Results
CPAP withdrawal led to a recurrence of OSA (mean difference in AHI between groups +39.7/h, 95%CI 32.7 to 46.7/h, p<0.001). In comparison to continuing CPAP, subtherapeutic CPAP led to a statistically significant increase in morning blood pressure; mean difference in systolic blood pressure +10.8mmHg (95%CI 5.2 to 16.4mmHg) and diastolic blood pressure +7.5mmHg (95%CI 3.5 to 11.5mmHg, both p<0.001), but was not associated with deterioration of myocardial perfusion (mean difference in hyperaemic myocardial blood flow -0.09ml/min/g, 95%CI -0.17 to -0.36ml/min/g, p=0.907).
Conclusions
Although short-term CPAP therapy withdrawal leads to a considerable increase in blood pressure, it is not associated with impaired myocardial perfusion. Thus, short-term discontinuation of CPAP does not seem to increase the risk of myocardial ischemia.
- © 2014 ERS