Cardiac Surgery in Patients with Dialysis-dependent End Stage Renal Failure: Single Centre Experience

Background: Patients under dialysis have a high cardiovascular risk and they are at increased risk when submitted to cardiac surgery.

Aim Of The Study: to evaluate morbidity, early and late mortality, and predictive factors of mortality in patients under dialysis who underwent cardiac surgery.

Methods: A retrospective observational study was performed including all dialysis dependent patients who underwent cardiac surgery (coronary, valvular or combined procedures) in our institution between 2007 and 2014. A population of 95 consecutive patients was obtained (no exclusions). Perioperative variables and predictors of mortality were analysed and the endpoints were early and late mortality. Propensity score matching, with a control group of patients with creatinine clearance >90mL/min, was performed by logistic regression, with a 1:1 matching. Kaplan Meier curves were performed for late mortality.

Results: Early mortality was 9.4% (EuroSCORE II 4.1%). In univariate analysis, mean time of cardiopulmonary bypass (CPB) (p=0.016) and EuroSCORE II (p=0.02) were related with early mortality. In a multivariate analysis model, combined procedures (OR 138.09; CI95% 1.82-10498.4; p=0.03) and CCS (Canadian Cardiovascular Society) 3-4 (OR 70.951; CI 95% 1.32-3810.11; p=0.037) were predictors of mortality. In multivariable analysis, CPB time >152 min was a predictor of early mortality (p=0.001). After propensity score matching, 30 day, one year and late mortality were higher in the dialysis group.

Conclusions: Early and late mortality were significantly higher in dialysis dependent patients. Predictive factors of mortality were CPB time and EuroSCORE II in univariable analysis, and CCS 3-4 and combined procedures in multivariable analysis.