Excess mortality in women undergoing aortocoronary bypass surgery has been linked to anaemia

American, Austrian and Swedish researchers conducted a cohort study and concluded that the higher mortality of women compared to men during aortocoronary bypass surgery (CABG) is largely due to anaemia during the intervention. A publication about this appeared in the Journal of the American College of Cardiology. In it Mario Gaudino (Mario Gaudino) from the Weill Cornell Medical School and colleagues analysed data from 1434225 patients (344357 of them women) who underwent primary ACS from the database of the Society of Thoracic Surgeons for the years 2011-2022. The researchers were interested in the influence of various factors on the excess risk of death during surgery.

It turned out that the median lowest haematocrit during ACS was lower in women (22 percent) than in men (27 percent). They had a higher mortality rate during the intervention, 2.8 versus 1.7 per cent (p < 0.001); odds ratio 1.36. The excess risk (AR) of death associated with female sex was 1.21. This decreased 43 percent to 1.12 after adjustment for the minimum haematocrit level was introduced. Intraoperative anaemia mediated 38.5 percent of the increased risk of death associated with female sex. The association between anaemia and mortality was strongest at minimum haematocrit values below 22 per cent. Maintaining haematocrit above this value during ACS may significantly reduce sex differences in mortality during this operation, the authors concluded.