Female patients have a higher incidence and greater severity of neurocognitive decline (NCD) after cardiac surgery. We investigated whether sex hormones play a role in this difference.

This was a retrospective cohort study at a single academic center. Sex hormone testing was performed on preoperative blood samples from 32 men and 30 postmenopausal women who underwent cardiac surgery. The Repeatable Battery for the Assessment of Neuropsychological Status measured patients’ preoperative and postoperative day 4 (POD4) neurocognitive function with scores scaled against normative data. Mann-Whitney U tests or t tests were applied as appropriate.

There were 62 patients (48.4% women) who underwent cardiac surgery and completed preoperative and POD4 neurocognitive testing. As expected, 8 men (25.0%) vs 21 women (70.0%) had NCD. Compared with women, men had higher β-estradiol levels (P = .009) and testosterone levels (P < .001) but similar progesterone levels (P = .14). Neither β-estradiol nor testosterone levels were significantly associated with NCD incidence in either men or women. Progesterone levels were decreased in NCD male patients (P = .01) but not in female patients (P = .64).

In the context of this exploratory analysis, differential expressions in sex hormones did not explain the higher incidence and severity of NCD after cardiac surgery in women, and alternative explanation and mechanisms should be further explored.