Chao, Chieh Ju

Abstract Aims : Direct oral anticoagulants (DOACs) are widely used for stroke prevention in people with non-valvular atrial fibrillation/flutter (NVAF). Anticoagulants have different bleeding profiles. Apixaban is associated with the lowest bleeding risk. This study evaluates the interaction between DOAC used and right ventricular systolic pressure (RVSP) on echocardiogram and bleeding rates. It was hypothesized that pulmonary hypertension may be associated with excess bleeding based on anticoagulant-specific pharmacologic profiles. Methods & Results : A retrospective analysis of a database was conducted. Multivariable regression models for bleeding rates were developed using a causative analysis approach among participants who had undergone an echocardiogram, and interaction terms for DOAC choice were incorporated. Stratum specific estimates were calculated using linear computation. Patients taking Apixaban had lower bleeding rates than those taking Rivaroxaban and Dabigatran. Among those without pulmonary hypertension, there was no difference in bleeding rates. Where RVSP was ≥45mmHg, there was a 90% increase in bleeding rates with use of Dabigatran (HR 1.99, p=0.024) and Rivaroxaban (HR 1.86, p=0.042) compared to Apixaban (Figure 1). Conclusions : Elevated RVSP is associated with excess bleeding in patients taking Rivaroxaban and Dabigatran, but not Apixaban, after controlling for confounding variables.

Introduction: The right ventricle (RV) strain measured by speckle tracking (RVS) is a novel method of assessing RV function. We compared RVS to RV fractional area change (FAC%), tricuspid annular peak systolic excursion (TAPSE) and Doppler tissue imaging-derived peak systolic velocity (S’) in the assessment of right ventricular (RV) systolic function measured using cardiac magnetic resonance imaging (MRI). Methods: We enrolled consecutive patients who underwent cardiac MRI between Jan 2012- Dec 2017 and a transthoracic echocardiogram (TTE) within 1 month of the MRI with no interval event. Baseline clinical characteristics and MRI parameters were extracted from chart review. Echocardiographic parameters were measured prospectively. TTE parameters including RVS, TAPSE, S’ and FAC% were tested for accuracy to identify impaired RV EF (EF <45% & <30%) using receiver operator curves. Results: The study cohort included 500 patients with mean age 55 yr ± 18 and right ventricular systolic pressure 33.7 ± 13.6 mmHg. The area under ROC for RVS was 0.69 (95% CI 0.63 – 0.75) and 0.78 (95% CI 0.70 – 0.88) to predict RVEF <45% & RVEF <30% respectively. The RV FAC % had second highest accuracy of predicting RVEF among all the TTE parameters tested in study. Conclusion: Right ventricular strain is the most accurate echocardiographic method to detect impaired right ventricular systolic function when using MRI as the gold standard.