Results
Forty-eight patients were included with pre-implantation and post-implantation catheterization data (Table 1). Of the 48 patients, 36 (77%) had CMR images available for analysis of RV mass (Table 2). Higher RV mass indexed to BSA was associated with higher RVSP, with a significantly higher average RV mass indexed seen with RVSP> 75% compared to 0%-49% (+31.9 \(g/m^{2}\), CI 7.5-56.4, p=0.012). There was no association between RVEF and pre-implantation RVSP in this cohort (p=0.7).
Ventricular Longitudinal Strain versus Right Ventricular Systolic Pressure Relationship
Elevated RVSP was significantly associated with a decrease in RV GLS, with every 14.3% increase in RVSP above 28% associated with an absolute magnitude 1% lower RV GLS at preimplantation (p=0.001). When the average pre-implantation RV GLS in was split into 3 categories based preimplantation RVSP: 0-49%, 50-74%, and >75%, the RV GLS was an absolute magnitude of 3.4% lower in those with RVSP >75% compared to 0%-49% (p=0.014). There was no significant association between pre-implantation LV GLS and RVSP as a continuous variable (p=0.141) or by RVSP categories (> 75%, p=0.435). Similar to the effect of pre-implantation RVSP on strain, a 6.3% increase in RVSP above 28% post TPVR was associated with an absolute magnitude 1% lower RV longitudinal strain (p<0.001). Age was not associated with significant change in RV (p=0.354) or LV GLS magnitude (p=0.235).
Overall, the RV GLS magnitude increased after TPVR from pre-implantation over time, with the greatest improvement immediately after valve implantation; however, on follow-up imaging performed within 18 months, the RV GLS was closer to pre-implantation values. The same trend was visualized in LV GLS strain magnitude over time (Figure 1). When categorized into 3 groups by RVSPP (0%-49%, 50%-74%, > 75%), the average strain value showed greatest improvement immediately post TPVR at 0%-49% compared to > 75% (Figure 2).
Pre-implantation Filling Pressure Effect on Ventricular Longitudinal Strain
For every 1 mmHg higher pre-implantation RVEDP, RV GLS absolute magnitude decreased by 0.26% (p=0.04). The pre-implantation LVEDP was not significantly associated with worsened LV GLS magnitude (p=0.788).