Risk factor analysis for survival in CardioWest total artificial heart recipients: A pilot study

Objectives: Little is known about preoperative risk factors for survival after CardioWest total artificial heart (TAH) implantation.

Methods: In a retrospective data analysis in 129 CardioWest TAH recipients from 2001 to 2012, we investigated to which extent preoperative patient characteristics, including clinical and biochemical parameters, can predict 90-day overall mortality. Univariate analyses were performed on 36 preimplantation prognostic factors. From this group, 6 factors were chosen for multivariate analysis.

Results: In total, 50 patients died within 90 days of TAH implantation. Of these patients, 49 were still ongoing on device when the event occurred, whereas one patient had already been transplanted. Overall 90-day mortality was thus 38.8%. Independent preoperative predictors for 90-day overall mortality were as follows: female sex (odds ratio [OR]: 4.12; 95% CI: 1.04 – 16.27) serum creatinine > 1.6 mg/dl (OR: 2.35; 95% CI: 1.07 – 5.13) and serum alkaline phosphatase > 120 U (OR: 3.10; 95% CI: 1.38 – 7.00). A weighted risk score (0 – 10 points) was developed. Of the patients with a zero score (23.8% of the study cohort) 22.6% died, whereas of the patients who scored 5 to 6 points (15.4% of the study cohort) and > 6 points (4.6% of the study cohort), 65.0% and 83.3%, respectively, died. The area under the receiver operating curve was 0.67 (95% CI: 0.58 – 0.77) (P = 0.001). By using a cut-off value of 5 points, sensitivity was 65.0% and specifity was 89.9%.

Conclusions: This pilot study indicates the possibility to predict 90-day mortality risk in TAH recipients by preoperative parameters. In future, a more refined risk score should be developed.