Right Ventricular-Pulmonary Arterial Uncoupling Thresholds in Acute Pulmonary Embolism

Area of Science:

• Cardiology
• Pulmonary Medicine
• Critical Care Medicine

Background:

• Right ventricle (RV) dysfunction is a key predictor of poor outcomes in acute pulmonary embolism (PE).
• Right ventricular-arterial (RV-PA) coupling, estimated by the tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) ratio, is crucial for assessing RV function.
• Assessing RV-PA uncoupling may offer further risk stratification in acute PE.

Purpose of the Study:

• To investigate the utility of RV-PA uncoupling in risk stratifying patients with acute pulmonary embolism (PE).
• To determine if the TAPSE/PASP ratio can identify patients with severe RV dysfunction and adverse outcomes in acute PE.

Main Methods:

• A retrospective analysis of 146 patients diagnosed with acute PE at a tertiary center.
• Statistical analysis using Kruskal-Wallis, Wilcoxon Rank Sum, and Chi-square tests to identify clinical features associated with RV-PA uncoupling.
• Categorization of RV-PA uncoupling into severe (< 0.31), moderate (0.31-0.4), and mild (> 0.4-1.75) based on prior studies.

Main Results:

• Severely impaired RV-PA uncoupling correlated with CT-defined RV dysfunction (RV/LV ratio > 0.9) and increased need for veno-arterial extracorporeal membrane oxygenation (VA-ECMO).
• A significant correlation was observed between the TAPSE/PASP ratio and BNP (r = -0.44) and lactate levels (r = -0.18).
• Established risk scores (ESC, sPESI, BOVA) did not differentiate between severity levels of RV-PA uncoupling.

Conclusions:

• Severely impaired RV-PA uncoupling in acute PE signifies more severe disease, indicated by elevated biomarkers and higher rates of VA-ECMO utilization.
• The TAPSE/PASP ratio serves as a valuable tool for risk stratification and guiding treatment decisions in acute PE.
• RV-PA uncoupling provides incremental prognostic information beyond traditional risk scores in acute PE.