Abstract Body (Do not enter title and authors here):
Introduction:
Right ventricular–pulmonary arterial (RV–PA) coupling refers to the relationship between right ventricular contractility and its afterload. This relationship can be noninvasively estimated using tricuspid annular plane systolic excursion (TAPSE) to pulmonary arterial systolic pressure (PASP) ratio. A study by Yurditsy et al. demonstrated that in patients with acute pulmonary embolism (APE) undergoing mechanical thrombectomy, the TAPSE/PASP ratio was a strong predictor of normotensive shock. By using noninvasive echocardiographic measurements to assess hemodynamics, this approach may offer valuable insights for enhanced PE risk stratification.
Research Question/Hypothesis:
We predict that the TAPSE/PASP ratio will strongly predict shock in patients with APE.
Methods:
This retrospective analysis examined 83 patients with low-risk, intermediate-risk, or high-risk APE who had complete invasive hemodynamic results and echocardiograms at a large quaternary care academic medical center. The patients were stratified into shock (CI <2.2) versus no-shock (CI >2.2) groups based on right heart catheterization measurements. Univariate testing was performed between the two shock groups with Student’s t-test for continuous variables and chi-squared testing for categorical variables. Receiver operating characteristic curves were constructed for both the TAPSE/PASP ratio and TAPSE alone to predict shock—with AUCs and 95% confidence intervals estimated by DeLong’s method, optimal thresholds identified via the Youden index, and a DeLong test applied to compare the difference in AUCs.
Results/Data:
Invasive hemodynamics identified 43 (52%) of our patients with cardiogenic shock. The age, gender, and race were evenly distributed among the shock and no-shock groups (Table 1). Patients classified in the shock group had a significantly lower TAPSE/PASP ratio compared to the no-shock group (Table 2). The TAPSE/PASP ratio yielded an area under the curve (AUC) of 0.76, with a sensitivity of 0.79, specificity of 0.63, positive predictive value of 0.69, and negative predictive value of 0.74. Notably, the TAPSE/PASP ratio had a significantly higher AUC for predicting shock compared to TAPSE alone (p=0.043) (Figure 1).

Conclusion:
In conclusion, the TAPSE/PASP ratio can be a useful non-invasive measurement in predicting shock in patients presenting with APE. The measurement can be used to quickly assess hemodynamics to further risk-stratify patients with an APE.