Relationship between left ventricular wall stress and cardiac remodelling post-TAVR and MitraClip.

Abstract

Background: The relationship between left ventricular wall stress (LVWS) and cardiac remodelling post structural intervention has not previously been examined. We examined the relationship between LVWS and cardiac remodelling 6 months post transcatheter aortic valve replacement (TAVR) and MitraClip (MC).

Methods: LVWS was calculated in 40 patients with severe aortic stenosis (AS) and 11 patients with severe mitral regurgitation (MR) immediately preintervention and postintervention with TAVR or MC. LVWS was calculated by integrating invasive haemodynamic data with cardiac MR (CMR)-derived measures of left ventricular (LV) volume and mass. Patients underwent a 6 min walk test (6MWT), transthoracic echocardiogram and CMR preprocedure and 6 months postprocedure.

Results: Both TAVR and MC resulted in significant improvements in functional capacity and cardiac remodelling with no significant difference in the degree of LV mass or volume reduction between the two groups.Linear regression analysis showed that baseline diastolic LVWS (D-LVWS) in the MC cohort and baseline systolic LVWS (S-LVWS) in the TAVR cohort were predictors of larger LV end-diastolic volumes (EDV) and lower ejection fractions (EF) at follow-up (in the MC cohort: B=7.86, p=0.015 for EDV, B=-1.4, p=0.02 for EF; in the TAVR cohort: B=1.53, p=0.04 for EDV and B=-0.702, p<0.001 for EF).

Conclusions: Higher baseline D-LVWS in patients undergoing MC, and higher baseline S-LVWS in patients undergoing TAVR, were predictors of poorer EF and larger LV volumes at follow-up. These findings suggest that LVWS may be used to predict the degree of LV recovery postprocedure and suggest that intervening below a certain LVWS threshold may lead to better outcomes with regards to cardiac remodelling.

Condensed abstract: LVWS was calculated in patients with AS and mitral regurgitation (MR) pre and immediately post valve intervention with TAVR or MC. The patients were followed up at 6 months with 6MWT, echocardiography and CMR imaging Both cohorts demonstrated significant functional improvements and cardiac remodelling postprocedure. Baseline D-LVWS in MC and baseline S-LVWS in TAVR were predictors of poorer EF and larger LV volumes at follow-up. This suggests that in patients with severe AS or MR, baseline LVWS may be useful to predict degree of recovery postintervention or determine need for early intervention.