The optimal core temperature for hypothermic circulatory arrest during aortic arch surgery remains contentious. This study aims to evaluate patient outcomes under various temperatures within a large single-centre cohort.

Between 2010 and 2018, patients diagnosed with type A aortic dissection underwent total arch replacement at Fuwai Hospital were enrolled. They were categorized into 4 groups: deep hypothermia group, low-moderate hypothermia group, high-moderate hypothermia group and mild hypothermia group. Clinical data were analysed to ascertain differences between the groups.

A total of 1310 patients were included in this cohort. Operative mortality stood at 6.9% (90/1310), with a higher incidence observed in the deep hypothermia group [29 (12.9%); 35 (6.9%); 21 (4.8%); 5 (3.4%); all adjusted P < 0.05]. Overall 10-year survival was 80.3%. Long-term outcomes did not significantly differ among the groups. Multivariable logistic analysis revealed a protective effect of higher core temperature on operative mortality (odds ratio 0.848, 95% confidence interval 0.766–0.939; P = 0.001). High-moderate hypothermia emerged as an independent protective factor for operative mortality (odds ratio 0.303, 95% confidence interval 0.126–0.727; P = 0.007). Multivariable Cox analysis did not detect an effect of hypothermic circulatory arrest on long-term survival (all P > 0.05).

High-moderate hypothermia (24.1–28°C) offers the most effective protection against surgical mortality and is therefore recommended. Different hypothermic circulatory arrest temperatures do not influence long-term survival or quality of life.