Cardiothoracic Surgery

Cardiothoracic subgroup findings were exploratory rather than definitive because of smaller samples and residual confounding concerns. Cardiothoracic surgery was analysed as an exploratory subgroup because it has inherently higher pulmonary risk. Cardiothoracic surgery was the strongest identified independent risk factor for major pulmonary complications. In cardiothoracic surgery, major pulmonary complication risk was significantly higher when surgery occurred within 7 weeks of COVID-19 infection than with no COVID-19. Cardiothoracic surgery risk was not significantly elevated at 7 to 9 weeks after infection.