Association of surgeon sex with postoperative adverse outcomes in adult cardiac surgery: a nationwide cohort study

Sex-based differences in outcomes after cardiac surgery are consistently reported, with women frequently experiencing higher postoperative morbidity and mortality. While emerging evidence suggests that patient-physician sex concordance may improve outcomes in some medical fields, whether such an effect exists in cardiac surgery is unknown. We conducted a nationwide cohort study using data from the Austrian Adult Cardiac Surgery Registry, including all patients undergoing one of four common non-emergent first-time cardiac surgery procedures between 2012 and 2022. The primary outcome was a composite of adverse postoperative outcomes, defined as death, readmission, or complications within 30 days after surgery. Multivariable generalized linear mixed models were used to assess patient-surgeon sex pairing effects. Among 57,729 patients (27.5% female) treated by 239 surgeons (22.2% female), patient-surgeon sex concordance was present in 63.9% of cases. Female patients had higher rates of the composite primary outcome compared to male patients (13.0% [female surgeon] and 13.3% [male surgeon] versus 11.0% [female surgeon] and 11.3% [male surgeon]). Surgeon sex was not independently associated with the primary composite outcome (aOR for female vs. male surgeon, 0.94; 95%CI, 0.84–1.06; P = 0.28), without significant interaction between patient and surgeon sex (p int =0.61). In this nationwide cohort, patient-surgeon sex pairing was not associated with postoperative adverse outcomes after adult cardiac surgery. Improving outcomes should therefore center on clinical risk optimization rather than sex concordance.