Total Beating-Heart Aortic Arch Repair Without Cardiac Arrest: A Proof-of-Concept Study

Background Cardioplegic arrest during complex aortic arch repair imposes prolonged global myocardial ischaemia, which may contribute to postoperative low cardiac output syndrome (LCOS) and mortality. Whether cardioplegic arrest can be entirely avoided -- performing the complete procedure on a continuously perfused, beating heart -- has not previously been evaluated in a clinical series. Methods and Results Between November 2017 and January 2026, 29 consecutive patients underwent total beating-heart aortic arch repair without any cardioplegic arrest at a single centre. Continuous antegrade myocardial perfusion (warm blood, 34{degrees}C, 300-400 mL/min, perfusion pressure 60-80 mmHg) was delivered via an aortic root needle vent throughout each procedure. Two variants were employed: axillary cannulation with selective antegrade cerebral perfusion (n = 24, 82.8%), and direct aortic cannulation with extra-anatomical left carotid bypass for distal Zone 2 pathology (n = 5, 17.2%). Mean age was 55.4 {+/-} 13.6 years; 41.4% presented with aortic dissection (B/non-A-non-B). No patient required conversion to cardioplegic arrest. Perioperative myocardial infarction and LCOS occurred in none of the patients. Median peak CK-MB was 44.0 U/L. Thirty-day mortality was 10.3% (n = 3); all deaths were due to respiratory failure or visceral ischaemia complicating acute type B dissection. Conclusions Total beating-heart aortic arch repair without cardioplegic arrest is technically feasible and clinically safe in appropriately selected patients and is associated with the complete absence of perioperative myocardial infarction and LCOS across a heterogeneous, high-risk cohort. These findings support prospective, multicentre evaluation of no-arrest myocardial protection as a strategy to reduce the cardiac morbidity of complex arch surgery.