Expected futility in reaching the primary endpoint

To assess if information about aortic calcification obtained from routine preoperative ultra low-dose chest CT lowers the postoperative stroke rate in patients undergoing heart surgery by optimizing surgical strategy compared to the normal work-up with a conventional chest X-ray.

During heart surgery the aorta is clamped to initiate cardiopulmonary bypass. This may crush aortic calcifications causing them to embolize to the brain causing a stroke which is a devastating complication for the patient. A chest X-ray is routinely performed prior to heart surgery. It provides no information about aortic calcification. Imaging by a chest computed tomography (CT) scan provides detailed information on aortic calcification but has higher radiation exposure and thus is not used routinely. Recently iterative reconstruction (IR) techniques have become available that allow chest CT to be performed at markedly reduced dose with retained image quality. Routine use of low dose chest CT with IR prior to heart surgery may identify patients with a severely calcified aorta in which the surgery may subsequently adapted to minimize or avoid aortic manipulation which may reduce stroke rate.

In this multicenter randomized controlled clinical trial the effect of preoperative chest CT on postoperative stroke is investigated. In total 1724 patients will be included of whom 862 patients will receive an additional CT to standard care and 862 patients will receive routine care.

Inclusion Criteria:

• 18 years old or older
• Scheduled to undergo heart surgery
• Provide written informed consent

Exclusion Criteria:

• Patient not meeting inclusion criteria
• Pregnant women
• Scheduled to undergo transcatheter aortic valve insertion procedure (since these patients receive a standard preoperative CT)
• Chest or cardiac CT in the past three months
• Emergency surgery
• Concomitant or previous participation in a study that prohibits the patient from participating in a study that exposed the patient to radiation
• Unwillingness to be informed about unrequested findings on the CT scan