(P136) VENTRICULAR-ARTERIAL DECOUPLING IS ASSOCIATED WITH IN-HOSPITAL ADVERSE EVENTS IN NORMOTENSIVE PULMONARY EMNBOLISM

Background: During acute pulmonary embolism (PE) a compensatory increase in right ventricular (RV) contractility is required to match increased afterload to maintain right ventricular-pulmonary arterial (RV-PA) coupling. When the RV is unable to match the increased afterload, RV-PA decoupling occurs resulting in RV failure and reduced cardiac output. The aim of this study was to assess the prognostic utility of transthoracic echocardiography (TTE) derived RV-PA decoupling in acute PE.

METHODS AND RESULTS: All patients ≥18 years of age admitted to the 4 academic hospitals in Calgary Alberta Canada between January 1, 2012 to March 31, 2017 with imaging confirmed PE (computed tomography or ventilation-perfusion imaging) and a TTE within 48 hours of diagnosis were retrospectively evaluated. We assessed the association between RV-PA coupling parameters including tricuspid annular plane excursion (TAPSE)/pulmonary artery systolic pressure (PASP), right ventricular fractional area change (FAC)/PASP and stroke volume index (SVI)/PASP with PE-related adverse events (in-hospital PE-related mortality or hemodynamic decompensation) using logistic regression analysis adjusted for age and sex. Receiver operating characteristic analysis was performed to assess the diagnostic performances of each RV-PA coupling parameter. In 820 normotensive patients there were 26 PE-related events including 11 PE-related deaths and 15 patients with hemodynamic decompensation. For each 0.1mm/mmHg decrease in TAPSE/PASP the odds of an adverse event increased by 2.5-fold (adjusted OR (aOR) 2.49, 95% confidence interval (CI) 1.46-4.24, p=0.001), for every 0.1 %/mmHg decrease in FAC/PASP the odds of an adverse event increased by 1.4-fold (aOR 1.42, CI 1.09-1.86, p=0.010), and for every 0.1mL/mmHg•m2 decrease in SVI/PASP the odds of an event increased by 2.75-fold (aOR 2.78, CI 1.72-4.50, p< 0.001). In multivariate analysis, TAPSE/PASP (p=0.044) and SVI/PASP (p=0.002) were independent of other risk stratification methods including computed tomography-derived RVD, the Bova score, and subjective assessment of TTE-derived RVD. In ROC analysis, the area under curve for TAPSE/PASP was 0.81 (CI 0.68-0.87), SVI/PASP was 0.89 (CI 0.83-0.96), and FAC/PASP 0.77 (CI 0.64-0.90). The AUC was higher for SVI/PASP compared to FAC/PASP (p < 0.01) but not TAPSE/PASP (p=0.13).

Conclusion: In patients with normotensive acute PE, TTE-derived measures of RV-PA coupling are strongly associated with adverse in-hospital PE-related events and provide incremental value in the risk assessment beyond computed tomography-derived RVD, the Bova score, or subjective assessment of TTE-derived RVD.