Pretransplant and perioperative predictors of early heart transplantation outcomes

Abstract

Aim To identify predictors of 3-month mortality after heart transplantation in a Croatian academic center. Methods A retrospective review of institutional database identified 117 heart transplantations from January 2008 to July 2014. Two children < 14 years were excluded from the study. The remaining 115 patients were dichotomized into survivors and non-survivors adjudicated at 3-months postoperatively, and their demographic, clinical, and longitudinal hemodynamic data were analyzed. Results 3-month survival after heart transplantation was 86%. Nonsurvivors were older (59 ± 8 vs 50 ± 14 years, P = 0.009), more likely to have previous cardiac surgery (44% vs 19%; odds ratio [OR] 3.28, 95% confidence interval [CI] 1.08-9.90; P = 0.029), lower body mass index (BMI) (25 ± 4 vs 28 ± 2 kg/m2, P = 0.001), and be diabetics (44% vs 23%; OR 2.57, 95% CI 0.86-7.66; P = 0.083). Creatinine clearance was marginally superior among survivors (59 ± 19 vs 48 ± 20 mL/min, P = 0.059). Donor age and sex did not affect outcomes. Nonsurvivors were more likely to have had ischemic cardiomyopathy (69% vs 32%, P = 0.010). Postoperative utilization of epinephrine as a second line inotropic agent was a strong predictor of mortality (63% vs 7%; OR 21.91; 95% CI 6.15-78.06; P < 0.001). Serum lactate concentrations were consistently higher among non-survivors, with the difference being most pronounced 2 hours after cardiopulmonary bypass (9.8 ± 3.5 vs 5.2 ± 3.2 mmol/L, P < 0.001). The donor hearts exhibited inferior early hemodynamics in non-survivors (cardiac index 3.0 ± 1.0 vs 4.0 ± 1.1 L/min/m2, P = 0.001), stroke volume (49 ± 24 vs 59 ± 19 mL, P = 0.063), and left and right ventricular stroke work indices (18 ± 8 vs 30 ± 11 g/beat/m2, P < 0.001 and 5 ± 3 vs 7 ± 4 g/beat/m2, P = 0.060, respectively). Non-survivors were more likely to require postoperative re-sternotomy (50% vs 12%; OR 7.25, 95% CI 2.29-22.92; P < 0.001), renal replacement therapy (RRT) (69% vs 9%; OR 22.00, 95% CI 6.24-77.54; P < 0.001), and mechanical circulatory assistance (MCS) (44% vs 5%; OR 14.62, 95% CI 3.84-55.62; P < 0.001). Binary logistic regression revealed recipient age (P = 0.024), serum lactates 2 hours after CPB (P = 0.007), and epinephrine use on postoperative day 1 (P = 0.007) to be independently associated with 3-month mortality. Conclusion Pretransplant predictors of adverse outcome after heart transplantation were recipient age, lower BMI, ischemic cardiomyopathy, reoperation and diabetes. Postoperative predictors of mortality were inferior donor heart hemodynamics, epinephrine use, and serum lactate concentrations. Non-survivors were more likely to require re-sternotomy, MCS, and RRT.