Cardiovascular

Predicting the right! Validation of right heart failure predictive risk models after primary durable ventricular assist device implantation.

TL;DR

Established right heart failure risk scores showed limited-to-moderate discrimination after durable left ventricular assist device implantation, with AUC values ranging from 0.394 to 0.729, while an exploratory Firth-penalized model achieved an optimism-corrected AUC of 0.773 but remains hypothesis-generating and requires external validation before clinical implementation.

Key Findings

Moderate-severe right heart failure occurred in 20.4% of patients following durable LVAD implantation.

  • 21 of 105 patients developed moderate-severe right heart failure
  • Single-center, retrospective observational study spanning April 2015 to February 2023
  • Right heart failure was defined according to the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) definition
  • The cohort of 105 patients underwent durable left ventricular assist device implantation

Among established preoperative right heart failure risk scores, discriminative performance was limited to moderate, with AUC values ranging from 0.394 (Utah) to 0.619 for most preoperative models.

  • Six established scores were evaluated: EUROMACS, Michigan, CRITT, BiVAD, Utah, and a modified Utah score
  • The Utah score had the lowest AUC of 0.394, indicating performance worse than chance
  • Discrimination was assessed using receiver-operating characteristic (ROC) analysis
  • Existing predictive risk models showed limited comparability and lacked consistent external validation

The postoperative EUROMACS score, which incorporates cardiopulmonary bypass time, achieved the highest AUC of 0.729 among established scores.

  • The postoperative EUROMACS score includes cardiopulmonary bypass time as a variable
  • It was analyzed separately as an early perioperative risk marker rather than a purely preoperative prediction tool
  • Authors note it 'should not be interpreted as a purely preoperative prediction tool'
  • Its AUC of 0.729 represented the best discrimination among all established scores tested

An exploratory Firth-penalized logistic regression model including five variables showed an apparent AUC of 0.854, which decreased to an optimism-corrected AUC of 0.773 after bootstrap validation.

  • The five variables included were: INTERMACS profile, total bilirubin, aspartate aminotransferase, diastolic pulmonary artery pressure, and pulmonary vascular resistance
  • Internal validation was performed using 2,000 bootstrap resamples
  • The optimism-corrected Brier score was 0.149 and the calibration slope was 0.586
  • A calibration slope of 0.586 indicated 'relevant optimism and potential overfitting'
  • The model was described as 'hypothesis-generating' and requiring external validation before clinical implementation

The exploratory Firth model identified a potentially informative combination of clinical status, hepatic laboratory markers, and pulmonary hemodynamics as predictors of right heart failure.

  • INTERMACS profile represented preoperative clinical status
  • Total bilirubin and aspartate aminotransferase served as hepatic laboratory markers
  • Diastolic pulmonary artery pressure and pulmonary vascular resistance represented pulmonary hemodynamic variables
  • Firth penalization was used to address potential issues with small sample size and rare events
  • The model remains hypothesis-generating due to its single-center derivation and evidence of overfitting

Perioperative right heart failure was identified as a severe complication after durable LVAD implantation for which accurate preoperative risk assessment is crucial.

  • Accurate preoperative risk assessment is needed to identify patients requiring advanced medical or mechanical biventricular support
  • The study aimed to validate commonly used right heart failure risk models using a standardized definition
  • A secondary exploratory analysis evaluated a parsimonious Firth-penalized model in the study cohort
  • Existing predictive risk models were noted to show 'limited comparability and lack consistent external validation'

What This Means

This research examined how well existing medical scoring tools can predict which patients will develop right heart failure after receiving a left ventricular assist device (LVAD) — a mechanical pump implanted to help a failing heart. Right heart failure is a serious complication that occurs in roughly 1 in 5 LVAD recipients, and knowing who is at high risk before surgery could help doctors plan more intensive support strategies. The study looked back at 105 patients who received LVADs at a single center over about eight years and tested six established prediction scores against the actual outcomes. The results showed that most established scoring systems performed poorly to moderately at identifying which patients would go on to develop significant right heart failure, with accuracy scores (AUC values) ranging from as low as 0.394 — meaning one score was actually worse than random guessing — to 0.729 for a score that incorporates information only available during or after surgery. The researchers also tested a new experimental model using five factors: a patient's overall clinical status before surgery, two liver function blood tests, and two measures of pressure in the lung's blood vessels. This new model showed better apparent accuracy, but when tested using a statistical technique to correct for the tendency of models to look artificially good on the same data used to build them, performance dropped noticeably, suggesting the model may be over-fitted to this specific group of patients. This research suggests that current tools for predicting right heart failure before LVAD surgery are inadequate, leaving clinicians without reliable guidance for one of the procedure's most serious risks. The experimental five-variable model offers a potentially promising direction — combining information about liver health and lung blood pressure alongside overall patient condition — but the authors emphasize it is hypothesis-generating only and cannot be used clinically until it is tested in independent patient populations. Larger, multi-center studies with standardized outcome definitions are needed to develop and properly validate better prediction tools.

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Citation

Sales M, Zayat R, Hatam N, Berg T, Tewarie L, Moza A, et al.. (2026). Predicting the right! Validation of right heart failure predictive risk models after primary durable ventricular assist device implantation.. PloS one. https://doi.org/10.1371/journal.pone.0357025