Peripheral ARtery Atherosclerotic DIsease and SlEep disordered breathing (PARADISE) trial - protocol for an observational cohort study.

BACKGROUND

Peripheral arterial disease (PAD) is in fact a group of disease entities with different symptoms and course but a common underlying cause, i.e. atherosclerosis. Atherosclerosis is known to be aggravated by several cardiovascular risk factors, including obstructive sleep apnoea (OSA).

AIM

Following paper is a protocol for the Peripheral ARtery Atherosclerotic DIsease and SlEep disordered breathing (PARADISE) trial, which aims to describe the prevalence of OSA in PAD patients scheduled for revascularisation, and to determine the effect of OSA on the procedure outcomes.

METHODS

The PARADISE study is an observational cohort trial. It plans to include 200 consecutive patients hospitalised for revascularisation due to PAD. In every patient an overnight sleep study will be performed to diagnose sleep disorders. Accord¬ing to the results of the test, patients will be divided into two groups: group A - patients with OSA, and group B - patients without OSA (control group). All patients will also be screened for classical and non-classical cardiovascular risk factors. In some of the patients, during surgery, a fragment of atherosclerotic plaque will be collected for further testing. Patients will be followed for one year for adverse events and end-points. Primary end-point of the study will be the failure of revascularisa¬tion defined as recurrence or new onset of the symptoms of ischaemia from the treated region, a need for re-operation or procedure revision, or recurrence of ischaemia signs on the imaging tests.

DISCUSSION

The data obtained will help determine the incidence of OSA in the population of patients with PAD. The au¬thors expect to show that, as with other cardiovascular diseases associated with atherosclerosis, also in patients with PAD the incidence of undiagnosed OSA is high and its presence is associated with elevated cholesterol, inflammatory markers, and higher prevalence of arterial hypertension and poor control of other cardiovascular risk factors. In addition, due to increased oxidative stress and vascular endothelial injury associated with OSA, patients afflicted with this condition will not only have more advanced atherosclerotic lesions, but also in their histopathological examination their atherosclerotic plaque will exhibit evidence of greater instability and adverse morphology. We also expect to show that in patients with OSA, achieving cor¬rect control of cardiovascular risk factors will be more difficult. The study may improve PAD control through assuring better multispecialty care in PAD patients.