Baseline left atrio-ventricular coupling predicts early improvement of right ventricular–pulmonary arterial coupling after TAVI: potential implications for patients selection
I P Isfan, E C Popa, A O Ciobanu, C A Udroiu, T Borjog, L S Magda, R C Rimbas, I E Mateescu, B Batagan, D VinereanuAbstract
Background
Right ventricular-pulmonary arterial (RV–PA) coupling reflects the interplay between RV contractility and afterload, and serves as a potential prognostic marker in aortic stenosis. Transcatheter aortic valve implantation (TAVI) reduces left-sided filling pressures and pulmonary pressures, which may enhance RV–PA coupling. However, impact of baseline left atrio-ventricular (LA–LV) coupling on how RV–PA coupling responds after TAVI is not yet fully understood.
Purpose
To assess: (1) extent of improvement in RV–PA coupling after TAVI; and (2) relation between LA–LV coupling and improvement in RV–PA coupling following TAVI.
Methods
We retrospectively analyzed 88 patients who underwent transfemural TAVI and had good quality pre- and early post-procedural echocardiographic studies. RV–PA coupling was assessed using TAPSE/sPAP ratio, Fractional Area Change (FAC)/sPAP ratio, RV lateral S’/sPAP ratio, and RV free-wall longitudinal strain (RVFWLS)/sPAP ratio. Post vs pre-procedural changes (Δ) were calculated. Baseline LA–LV coupling was assessed using left atrial coupling index (LACI), calculated as the ratio of LA end-diastolic volume to LV end-diastolic volume. Linear regression models assessed the relationship between baseline LACI and ΔRV-PA indices.
Results
Early post-TAVI, after a median of 2.5 (2-5) days, sPAP decreased significantly (from 31.1±12.4 to 24.5±13.4 mmHg; p<0.001). Among isolated RV functional parameters (TAPSE, FAC, RV lateral S', and RVFWLS), only FAC and RV lateral S' showed significant improvement post-TAVI. However, when incorporated into the RV–PA coupling indices, significant post-TAVI improvement was observed in all these indices (all p<0.001) (Figure 1). Restricted cubic spline analyses demonstrated linear associations of LACI with all ΔRV-PA coupling indices, with no evidence of non-linearity (all p for non-linearity >0.7). Higher pre-TAVI LACI was independently associated with smaller improvements in all RV-PA coupling indices, even after adjustment for baseline values of indices and for sPAP: ΔRVFWLS/sPAP (β −0.013, 95%CI −0.02 to −0.005; p=0.006), ΔTAPSE/sPAP (β −0.009, 95%CI −0.016 to −0.002; p=0.01), ΔFAC/sPAP (β −0.016, 95%CI −0.032 to −0.0003; p=0.04), ΔS’/sPAP (β −0.004, 95%CI −0.008 to −0.00006; p=0.04) (Figure 2). Adjustment for sPAP was deemed mandatory given the independent association of LACI with ΔsPAP (p<0.001).
Conclusion
RV–PA coupling significantly improves early after TAVI, predominantly due to decrease of the systolic pulmonary arterial pressure, rather than to the intrinsic RV functional changes. However, advanced pre-TAVI LA–LV uncoupling identifies patients less likely to achieve right heart hemodynamic recovery early after TAVI. These results support earlier referral to TAVI, before decline of the left heart hemodynamics. This might improve patients selection and optimize timing for TAVI.Figure 1Figure 2