One-year survival of patients with a prolonged ICU stay after cardiac surgery -: Predictors for a bad prognosis

Background: In particular in elderly patients, complicated cardiac surgery is often associated with a prolonged postoperative ICU stay and an uncertain prognosis. The aim of this study was to determine the one-year survival of such patients, and to identify predictors of a poor prognosis. Methods: Over a period of two years, the data of all patients needing a postoperative ICU stay of 7 or more days after heart surgery were analysed retrospectively. Patients undergoing thoracic organ transplantation were excluded. One year after operation, all patients or their relatives were contacted. For the statistical analyses the t-test, Fisher's exact test and a logistic regression were applied. Results: 107 patients (76 males, 31 females; mean age 65.3 +/- 10.9 years) had a prolonged ICU stay (range 7 to 143 days; mean 19.6 +/- 18.8 days) after heart surgery (41.1% coronary artery surgery, 7.5% aortic valve surgery, 7.5% mitral valve surgery, 14.0% combinated coronary artery and valve surgery, 3.7% aortic surgery, and 26.2% other cardiac surgery procedures). 80 patients (74.8%) survived the first postoperative year, while 27 patients (25.2%) did not; of these, 14 (51.9%) died while still in hospital. The deceased significantly more often had pulmonary hypertension (29.6% vs. 10.1%, p=0.026), atrial fibrillation (29.6% vs. 11.3%, p=0.034) and a creatinin value above 1.6 mg/dl (33.3% vs. 12.5%, p=0.021) preoperatively, continuous infusion of catecholamins (88.9% vs. 68.8%, p=0.045) intraoperatively, and underwent dialysis (63.0% vs. 30.4%, p=0.005), cardiac resuscitation (40.7% vs. 17.7%, p=0.020), mechanical ventilation for more than 11 days (85.2% vs. 29.1 %, p<0.001), or an ICU stay of more than 14 days (70.4% vs. 40.0%, p=0.008) postoperatively. The risk of dying within the first year increases in the presence of pulmonary hypertension (odds ratio 6,7) or mechanical ventilation for more than 11 days (odds ratio 15.5). Conclusions: The chances of surviving a prolonged and complicated ICU stay after cardiac surgery beyond the first postoperative year are unexpectedly high. Pulmonary hypertension and mechanical ventilation for more than 11 days have the greatest negative impact on prognosis.