From the Guidelines
The most commonly used risk scores to predict right ventricular (RV) failure prior to left ventricular assist device (LVAD) implantation include the HMII Risk Score, Michigan RV Risk Score, CRITT Score, Penn Score, and the Utah RV Risk Score, as well as the EUROMACS-RHF risk score, which incorporates INTERMACS class, severe RV dysfunction, severe tricuspid regurgitation, hemoglobin, and use of multiple inotropes 1. These scores help clinicians identify patients at high risk for RV failure after LVAD placement, which is crucial because RV failure significantly increases morbidity and mortality post-LVAD. Some key factors that are considered in these risk scores include:
- Preoperative use of vasopressors
- Elevated AST/total bilirubin
- Elevated creatinine
- Severe RV dysfunction on echocardiography
- Tricuspid regurgitation
- Elevated central venous pressure
- Low pulmonary artery pressure
- Low RV stroke work index
- Need for mechanical ventilation Early identification of high-risk patients allows for preoperative optimization, consideration of biventricular support, or temporary RV support strategies. Despite their utility, these scores have limitations in predictive accuracy, and clinical judgment remains essential in the comprehensive evaluation of LVAD candidates 1. It is also important to consider other factors that may affect RV function, such as tricuspid valve disorders, shunts, structural heart disease, hepatic dysfunction, and kidney dysfunction, as these can impact the patient's outcome and the success of the LVAD implantation 1.
From the Research
RV Failure Risk Scores
The RV failure risk score is a pre-operative tool used to assess the risk of right ventricular failure in left ventricular assist device (LVAD) candidates. The score is calculated based on several pre-operative clinical, laboratory, echocardiographic, and hemodynamic predictors of RV failure, including:
- Vasopressor requirement (4 points) 2
- Aspartate aminotransferase > or =80 IU/l (2 points) 2
- Bilirubin > or =2.0 mg/dl (2.5 points) 2
- Creatinine > or =2.3 mg/dl (3 points) 2
Calculation of RV Failure Risk Score
The RV failure risk score (RVFRS) is calculated by adding the points for each predictor. The odds ratio for RV failure for patients with an RVFRS < or =3.0,4.0 to 5.0, and > or =5.5 were 0.49,2.8, and 7.6, respectively 2.
Predictive Value of RV Failure Risk Score
The RVFRS has been shown to effectively stratify the risk of RV failure and death after LVAD implantation, with an area under the receiver-operating characteristic curve of 0.73 +/- 0.04 2. The Michigan RVF score, which emphasizes preoperative hemodynamic instability and target end-organ dysfunction, has also been shown to be a significant predictor of RVF and in-hospital and long-term mortality 3.
Comparison of RV Failure Risk Scores
A comparative analysis of established risk scores and novel hemodynamic metrics in predicting RV failure in LVAD patients found that the Michigan RVF score was the only risk model to demonstrate significant discrimination for RVF 3. Other studies have also highlighted the importance of preoperative evaluation and perioperative management of RV failure after LVAD implantation 4, 5.