Internal Medicine Resident University of Houston/ HCA Houston Clear Lake League City, Texas, United States
Disclosure(s):
Yves Najm Mrad, MD, MPH, MSAI: No financial relationships to disclose
Background: Failure of temporary mechanical circulatory support (MCS) is driven by right ventricular (RV) dysfunction and inadequate coupling between RV contractility and pulmonary arterial afterload. To quantify RV–pulmonary arterial (RV-PA) coupling, the prognostic value should be evaluated. We conducted a meta-analysis to assess RV-PA coupling metrics as predictors of MCS failure.
Methods: A systematic search of PubMed, Embase, Web of Science, and Cochrane databases was performed through December 2025. Studies were included if they evaluated RV-PA coupling indices—such as pulmonary artery pulsatility index (PAPi), TAPSE/PASP ratio, RV stroke work index, or related measures—in adult patients receiving temporary MCS and reported outcomes including inability to wean from support or death while on support. Random-effects meta-analysis was used to pool effect estimates. Heterogeneity was assessed using I² statistics, with subgroup analyses by MCS modality.
Outcome: Eight observational studies including 684 patients met inclusion criteria. Impaired RV-PA coupling was consistently associated with MCS failure. Low PAPi was a strong predictor of adverse outcomes; PAPi below approximately 1.0 was associated with a markedly increased risk of MCS failure (pooled OR 4.76, 95% CI 2.50–9.06; p< 0.001). Each incremental increase in PAPi was associated with reduced failure risk (OR 0.85 per 0.1 increase, 95% CI 0.80–0.90). Echocardiographic coupling metrics demonstrated similar prognostic value; a low TAPSE/PASP ratio was associated with significantly higher odds of MCS failure (OR 3.94, 95% CI 1.72–9.02; p=0.001). Heterogeneity was moderate (I²=42–58%) but effect direction was consistent across device types, including VA-ECMO and percutaneous ventricular assist devices.
Conclusion: RV-PA coupling metrics are powerful predictors of temporary MCS failure. Low PAPi and depressed TAPSE/PASP identify patients at high risk regardless of MCS platform. Assessment of RV-PA coupling improves risk stratification, biventricular support escalation, and weaning strategies. Incorporating RV-PA coupling metrics into cardiogenic shock and MCS algorithms is crucial.
