Ventricular interaction and clinical outcomes in patients undergoing transcatheter tricuspid valve repair

Abstract Background Excessive volume overload of the right ventricle (RV) due to tricuspid regurgitation (TR) can cause a leftward shift of the interventricular septum and changes left ventricular (LV) geometry, which leads to decreases LV distensibility and results in cardiac output. This unfavorable ventricular interaction might have prognostic impacts of patients undergoing transcatheter tricuspid valve repair (TTVr). Purpose We investigated the association between the ventricular interaction and clinical outcomes in patients undergoing TTVr. Methods We retrospectively assessed 304 patients who underwent TTVr. The ventricular interaction was assessed using LV eccentricity index which was defined as LV antero-posterior dimension / LV septo-lateral dimension at end-diastole in the parasternal short-axis view (Figure 1). Increased ventricular interaction was defined as LV eccentricity index ≥1.2. The primary outcome was a composite of all-cause mortality and heart failure hospitalization within one year after TTVr. Results The mean LV eccentricity index at baseline was 1.23 ± 0.20, and 168 of 304 patients (55.3%) had increased ventricular interaction. Patients with increased ventricular interaction were more likely to have massive or torrential TR, reduced RV function, larger RV areas, and lower cardiac index. Increased ventricular interaction at baseline was associated with an increased risk of the composite outcome (HR 2.14; 95%CI 1.36–3.37; p=0.001; Figure 2A), which was consistent after adjusting for age, male sex, renal function, LV ejection fraction, RV function, and residual TR. Echocardiography at baseline showed that 83 of 168 patients (49.4%) with increased ventricular interaction at baseline had an improvement in the ventricular interaction (i.e., LV eccentricity index ≥1.2 at baseline but <1.2 at discharge), which was associated with a lower risk of the composite outcome than persisted ventricular interaction (i.e., LV eccentricity index ≥1.2 at both baseline and discharge) (Figure 2B), irrespectively of baseline characteristics and residual TR. Smaller RV area and residual TR ≤2+ were related to the improved ventricular interaction. Conclusion Ventricular interaction, defined as LV eccentricity index ≥1.2, is associated with an increased risk of clinical outcomes after TTVr. However, the post-procedural improvement in ventricular interaction after TTVr may be linked to better prognosis.Figure 1Figure 2