Introduction: Multidisciplinary pulmonary embolism response teams (PERT) have gained popularity in the treatment of submassive and massive pulmonary embolism (PE). One purpose of the PERT is to determine which patient(s) could benefit from advance treatment, including catheter directed lysis (CDL). A proven effect of CDL is more rapid lowering of right ventricular (RV) pressures. Findings of RV strain on echocardiography (echo) can predict in hospital mortality in patients with PE, but less is known about its accuracy for catheter-derived RV pressure in patients with acute PE.
Hypothesis: Echo measurements of the RVSP (from Bernoulli’s equation), RV fractional area change (FAC), right ventricle: left ventricle (RV:LV) ratio and tricuspid annular plane systolic excursion (TAPSE) can predict catheter-measured RV systolic pressures.
Methods: All patients had image proven PE and signs of right heart strain by evidence-based guidelines. Echo was obtained via a RDCS certified sonographer. Catheter-measured RV pressures were recorded prior to fibrinolysis. All echos were interpreted by a board certified cardiologist blinded to the study’s hypothesis and catheter data. Correlation was assessed with Pearson’s coefficient (R^2), and weighted Cohen’s κ was used for agreement with RV FAC, RV:LV ratio and TAPSE. A Bland-Altman plot assessed agreement between RV systolic pressures (RVSP) estimated by echo and catheterization.
Results: From May 2014 to December 2016, 53 PERT patients underwent echo and CDL. Thirteen echos were technically inadequate to evaluate the tricuspid regurgitant jet velocity and/ or IVC visualization for RVSP. The mean RVSP (mm Hg) was 45 ±13 from echo versus 49+/-13 from catheter, and R^2=0.5 (95% CI 0.44-0.86). Cohen’s κs were as follows RVSP (0.28, 0.01-0.59) FAC (0.05, -0.29-0.18), RV:LV (0.01, -0.27-0.29), TAPSE (0.36, 0.15-0.56). Bland Altman bias was -2.69 with 95% limits of agreement (-22 to 17) for RVSP.
Conclusions: The echo estimated RVSP and other indexes of RV strain are frequently limited by poor acoustic windows and lack of correlation with catheter-obtained RV pressures in patients PE. Only TAPSE and RVSP showed fair agreement. These data call into question the utility of using echo routinely in PERT response protocols.