Preoperative factors primarily include the patient's existing comorbidities and physiological status, such as underlying diseases like pulmonary hypertension (especially mean pulmonary arterial pressure >35 mmHg), chronic obstructive pulmonary disease, and diabetes; preoperative use of steroids or immunosuppressants; and elevated levels of inflammatory markers such as C-reactive protein. This evidence concerns the gene CRP and pulmonary hypertension.