Rationale and design of the Canadian Continuous Positive Airway Pressure Trial for Congestive Heart Failure patients with Central Sleep Apnea--CANPAP.
BACKGROUND
Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is commonly observed in patients with congestive heart failure (CHF), in which it is an independent risk factor for death. Treating CSR-CSA may, therefore, improve outcomes in patients with CHF.


OBJECTIVE
The Canadian Continuous Positive Airway Pressure Trial for Congestive Heart Failure Patients with Central Sleep Apnea (CANPAP) is a multicentre, randomized, controlled clinical trial designed to test the hypothesis that treating CSR-CSA with continuous positive airway pressure (CPAP) will reduce the combined rate of all-cause mortality and cardiac transplantation in patients with CHF. Secondary outcomes include the severity of CSR-CSA, left ventricular volumes and function, submaximal exercise capacity, quality of life and hospital admissions.


METHODS
The aim is to enroll 408 patients with CHF (New York Heart Association class II to IV and left ventricular ejection fraction of less than 40%) and CSR-CSA over a five-year period. Patients are randomly assigned to either standard medical therapy for CHF or standard medical therapy plus CPAP. The trial has 80% power to detect a 35% between-group treatment difference for the all-cause mortality-cardiac transplantation rate. Substudies will assess the role of oximetry as a screening tool for detecting CSR-CSA in patients with CHF, and the effects of CPAP on cardiac arrhythmias and plasma concentrations of natriuretic peptides and catecholamines.


CONCLUSIONS
The CANPAP trial will help to define the role of CPAP better as a nonpharmacological intervention for the treatment of patients with CHF who have CSR-CSA.
Bradley
T D
TD
Department of Medicine, Toronto General Hospital of the University Health Network, Toronto, Canada. douglas.bradley@utoronto.ca
Logan
A G
AG
Floras
J S
JS
D002170:Canada; D006333:Heart Failure / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D015337:Multicenter Studies as Topic; D011175:Positive-Pressure Respiration; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D012891:Sleep Apnea Syndromes / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*