Diagnostic Accuracy of Ct-Reported Right Ventricular Strain in Acute Pulmonary Embolism

Background Acute pulmonary embolism is the third leading cause of cardiovascular mortality in the United States. Treatment of submassive pulmonary embolism in a hemodynamically stable patient is still controversial in terms of who would benefit from advanced treatment options such as catheter guided thrombolysis. Specifically, it is not clear how the CT reported right ventricular (RV) strain compares to the gold standard, echo derived RV free wall longitudinal strain. Limited or no data exists in the literature comparing these two modalities for assessment of RV strain. Methods We conducted a retrospective study of 142 patients admitted to Mayo Clinic Arizona with a diagnosis of acute pulmonary embolism who had both echo derived RV strain and CT reported RV strain. Results Patients mean age was 62 yrs. Comorbidities consisted of COPD (5%), asthma (16%), OSA (30%), diabetes (24%), hypertension (57%) and Covid 19 infection (13%). Echographic evaluation revealed mean left ventricular ejection fraction of 60%, right ventricular systolic pressure of 43 mm Hg, and mean RV free wall longitudinal strain of -19%. Specifically, 65% of the patients had abnormal echo derived RV strain (-24% or more negative strain is considered normal), while 45% had abnormal CT reported RV strain. Using echo RV strain as the gold standard, CT reported RV strain has a sensitivity of 58%, specificity of 80%, PPV of 84% and NPV of 50%. Conclusion Our study results suggest that CT reported RV strain has relatively low negative predictive value indicating that these patients would benefit from echo derived RV strain measurements so that potential candidacy for advanced treatment options can be considered. Further studies are needed to understand why there are discrepancies between echo vs. CT reported RV strain. More importantly, additional studies with longer follow-up will be needed to determine whether prognosis is different based on CT vs. Echo guided advanced treatment considerations.