Predicting survival after Impella implantation in patients with cardiogenic shock: The J-PVAD risk score

Aims: Impella has become a new option for mechanical circulatory support in patients with cardiogenic shock (CS); however, prognostic models for patients after Impella are lacking. We aimed to identify the factors that predict in-hospital mortality in patients with CS requiring Impella and develop a new risk prediction model. Methods and results: We utilized the J-PVAD registry, which includes all cases where Impella was implanted in Japan. Two-thirds of the patients in the J-PVAD registry were randomly assigned to the derivation cohort (n = 1701), and the other third was assigned to the validation cohort (n = 850). A backward stepwise logistic regression model was developed to identify factors associated with in-hospital mortality. In the derivation cohort, 956 patients were discharged alive, and 745 patients (43.8%) died during hospitalization. Among 29 candidate variables, 12 were independently associated with in-hospital mortality and were applied as components of the risk model, including age, sex, body mass index, fulminant myocarditis aetiology, cardiac arrest in hospital, baseline veno-arterial extracorporeal membrane oxygenation use, mean arterial pressure, lactate, lactate dehydrogenase, total bilirubin, creatinine, and albumin levels. The comparison of predicted and observed in-hospital mortality according to the 7th quantiles using the J-PVAD risk score showed good calibration. The area under the curve for the J-PVAD risk score was 0.76 (95% confidence interval 0.73–0.78). In the validation cohort, the J-PVAD risk score showed good calibration and discrimination ability. Conclusions: The J-PVAD risk score can be calculated using variables easily obtained in routine clinical practice. It helps the accurate stratification of mortality risk and facilitates clinical decision-making.