The following is a summary of “Prediction of Survival After Implantation of a Fully Magnetically Levitated Left Ventricular Assist Device” published in the December 2022 issue of Heart Failure by Mehra et al.
While clinical trials are useful for providing an overview of treatment’s average effectiveness, individual risk assessments for outcome prediction are essential for making treatment decisions. Survival at 1 and 2 years after implantation of a HeartMate 3 (HM3) left ventricular assist device (LVAD) was predicted using a patient-specific risk score that the authors created and validated. Patients with HM3 LVADs make up the bulk of the 2,200 participants in the MOMENTUM 3 (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3) trial’s main trial and Continued Access Protocol study (2014-2018). All patients were divided at random into 2 groups: a derivation cohort (n=1,540) and a validation cohort (n=660).
The performance (discrimination and calibration) of a multivariate Cox proportional hazards regression model was examined after screening univariate mortality variables for prospective model inclusion, followed by the construction of the model. Significant risk factors for death included older age, a history of cardiac surgery (coronary artery bypass grafting [CABG] or valve procedure), lower serum sodium, higher blood urea nitrogen (BUN), smaller left ventricular size, and a right atrial pressure-to-pulmonary capillary wedge pressure (RAP/PCWP) ratio of more than 0.6. In addition, an area under the curve (AUC) of 0.76 (95% CI: 0.70-0.81) was found after 1 year of follow-up in the validation cohort, while AUCs of 0.71 (0.66-0.77) were found after 2 years.
The Pearson correlation coefficients at 1 and 2 years showed a high level of calibration between predicted and observed survival of the risk quintiles. The observed mortality risk doubled from 1 tertile to the next, and patients were successfully categorized into tertiles with higher-than-average, average, and lower-than-average survival. To reliably predict 1- and 2-year survival after HM3 LVAD implantation, a practical, user-friendly HM3 Survival Risk Score with 6 components was created. An individual’s survival time after HM3 LVAD therapy can be estimated using a survival risk score, allowing for more informed and collaborative decision making.