Rationale and design of the CONSIDER AF study: Impact of sleep-disordered breathing on atrial fibrillation and perioperative complications in patients undergoing coronary artery bypass grafting surgery

Background The objectives of the CONSIDER AF (NCT02877745) observational study are to evaluate the impact of sleep-disordered breathing (SDB) on the rate of major adverse cardiac and cerebrovascular events in patients undergoing elective coronary artery bypass grafting (CABG) surgery. In addition, explorative analyses will allow specification of subgroups of patients with SDB with the highest risk for peri- and postoperative complications. Methods CONSIDER AF is a single-center study in patients with and without SDB undergoing elective CABG. The presence and type of SDB are assessed the night prior to CABG using portable SDB monitoring. SDB is defined as an apnea–hypopnea index ≥15/h. Biomaterials (atrial myocardium and blood cells) are systematically sampled. New-onset atrial fibrillation and peri- and postoperative complications are prospectively evaluated during the hospital stay and over a period of 2 years. The relationship between postoperative complications and SDB or covariables associated with postoperative complications in univariable analyses are determined by multivariable logistic regression. Moreover, length of hospital stay and time spent in the intensive/intermediate care unit (ICU/IMC) of patients with and without SDB are analyzed. The harvested biomaterials are analyzed for novel signaling events and biomarkers. Discussion The prospective observational CONSIDER AF study is needed to identify specific risks, including SDB, and risk populations in cardiac surgery. In addition, CONSIDER AF has the potential to generate the rationale for hypotheses regarding peri- and postoperative management of patients with SDB to be tested in future randomized clinical trials. Based on this knowledge, the peri- and postoperative management of patients with SDB may be optimized.