Simplified Acute Physiology Score II Predicts Mortality and Length of Stay Better than EuroSCOREs in Patients Undergoing Transcatheter Aortic Valve Implantation: A Single-Center Experience

Objectives: Simplified Acute Physiology Score (SAPS) II is a prognostic score for predicting the outcome of critically ill patients on admission in intensive care units (ICU). Our objective is to assess its utility in transcatheter aortic valve implantation and to compare it to Logistic EuroSCORE and EuroSCORE II.

Methods: We retrospectively analyzed prospective data from patients who underwent a transcatheter aortic valve implantation (TAVI) from July 2009 to March 2017. After the procedure patients were extubated in a hybrid operating room according to our fast track protocol and thereafter admitted to the intensive care unit where SAPS II was prospectively calculated. Kolmogorov-Smirnov test was used to test continuous variables for normal distribution. A Spearman's test was used to evaluate correlation with length of ICU- and hospital stay. Calibration and discrimination for 30-day mortality have been calculated through Hosmer–Lemeshow and receiver operating characteristic (ROC) analysis respectfully.

Results: A total of 782 TAVI procedures were performed in 782 patients. The procedure was performed via transapical (TA) access in 282 patients (36%) and via transfemoral (TF) access in 500 patients (64%). Patients in TA group had a longer ICU- (4.0 ± 5.9 vs. 2.1 ± 3.6 days, p < 0.001) and hospital stay (14.3 ± 9.8 vs. 11.0 ± 8.6 days, p < 0.001) and higher mortality (8 vs. 4%, p = 0.02) than those in TF group. Logistic EuroSCORE and EuroSCORE II were higher in TA compared to TF group (28.5 ± 17.4 vs. 22.0 ± 14.7, p < 0.001 and 11.1 ± 9.3 vs. 8.1 ± 7.2, p < 0.001), but SAPS II was not significantly different between the groups (28.9 ± 10.9 vs. 29.6 ± 14.6, p = 0.56). SAPS II correlates with the length of ICU (p < 0.001) and hospital stay (p < 0.001) in both groups; there is, however, no correlation between Logistic EuroSCORE and EuroSCORE II with the length of ICU and hospital stay. Hosmer–Lemeshow test for 30-day mortality was not significant in both groups for all the scores. According to receiver operating characteristic, SAPS II offers a superior discrimination for 30-day mortality than logistic EuroSCORE or EuroSCORE II in TF (area under the curve = 0.72 vs. 0.65 vs. 0.64, respectively) and TA group (area under the curve = 0.60 vs. 0.56 vs. 0.57, respectively).

Conclusions: SAPS II correlates with the length of ICU and hospital stay and offers a fair discrimination for 30-day mortality in both TA and TF TAVI patients. It is superior to logistic EuroSCORE and EuroSCORE II in discrimination for 30-day mortality.