Ultra low-dose chest ct with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery (CRICKET study): Rationale and design of a multicenter randomized trial

Background: Stroke after cardiac surgery is a severe complication with a persistently high incidence of 1.4 - 9.7%. Postoperative strokes are mainly embolic and can be provoked by manipulation and clamping of the aorta during cardiac surgery, resulting in the mobilization of atherothrombotic material and calcifications from the aortic wall. Computed tomography (CT) can offer preoperative visualization of aortic calcifications with low radiation exposure. We hypothesize that preoperative knowledge regarding the location and extent of aortic calcifications can be used to optimize surgical strategy and decrease postoperative stroke rate. Methods/design: The CRICKET study (ultra low-dose chest CT with iterative reconstructions as an alternative to conventional chest x-ray prior to heart surgery) is a prospective multicenter randomized clinical trial to evaluate whether non-contrast chest CT before cardiac surgery can decrease postoperative stroke rate by optimizing surgical strategy. Patients scheduled to undergo cardiac surgery aged 18 years and older are eligible for inclusion. Exclusion criteria are pregnancy, a chest/cardiac CT in the past three months, emergency surgery, concomitant or prior participation in a study with ionizing radiation and unwillingness to be informed about incidental findings. Subjects (n = 1.724) are randomized between routine care, including a chest x-ray, or routine care with an additional low dose chest CT. The primary objective is to investigate whether the postoperative in-hospital stroke rate is reduced in the CT arm compared to the routine care arm of the randomized trial. The secondary outcome measures are altered surgical approach based on CT findings and cost-effectiveness.