Patients with low-flow, low-gradient (LFLG) aortic stenosis got at least as much benefit from transcatheter aortic valve replacement (TAVR), even if they went in with severe left ventricular (LV) dysfunction, researchers showed.
LV ejection fraction (LVEF) actually increased more in the first year after the procedure among those who started below 30% than in those with milder LV dysfunction (absolute LVEF increase 11.9% vs 3.6%, P<0.001), according to Josep Rodés-Cabau, MD, of Quebec Heart & Lung Institute at Laval University in Quebec City, and colleagues.
Mortality over the 23-month follow-up was similar whether LVEF had been less than 30% or in the 30% to 40% range, the investigators reported in a 293-person substudy of the multicenter TOPAS-TAVI registry, published online in JAMA Cardiology.
In a 99-person subset with very low LVEF, half of these patients lacked contractile reserve (an observed increase of 20% or more in stroke volume) on dobutamine stress echocardiography (DSE) before TAVR. This group had the same clinical outcomes and improvement in LVEF as the rest of the group, however.
“Importantly, most patients demonstrated a significant improvement in their LVEF over time, irrespective of the degree of baseline LV dysfunction and the presence or lack of contractile reserve. Thus, patients with LFLG severe aortic stenosis should not be declined for aortic valve replacement procedures on the basis of the degree of LVEF dysfunction or the results of DSE,” Rodés-Cabau’s group concluded.
These researchers had previously found from the TOPAS-TAVI registry that there was no association between DSE results and LV function recovery or clinical outcomes; now their findings are extended to patients with very low LVEF.
“This is somewhat surprising, because it has long been assumed that the presence of contractile reserve would identify patients with better LV recovery and better long-term outcomes after TAVR. However, this does not appear to be the case. Clearly, further research is necessary in order to identify factors that can help to predict long-term benefit in this challenging patient population,” commented David Cohen, MD, of Saint Luke’s Mid America Heart Institute in Kansas City, Mo. He was not involved in the study.
The subjects followed by Rodés-Cabau and colleagues were a mix of those with data collected retrospectively and prospectively in the years spanning 2007 to 2018. Patients had to have LFLG aortic stenosis, defined as mean transvalvular gradient less than 35 mm Hg, effective orifice area under 1.0 cm2, and LVEF less than 40%.
The group averaged age 80, and 73% were men. It was split between those with sub-30% LVEF (43.7% of patients, with mean LVEF of 22%) and 30% to 40% LVEF (mean LVEF 37%).
Having more than a quarter of the very low LVEF group not get DSE assessment was a key limitation of the study, the authors said, along with the potential for patient selection bias in the registry.
The study was funded by a grant from the Canadian Institutes of Health Research.
Rodés-Cabau reported institutional research grants from Edwards Lifesciences and Medtronic.
Cohen disclosed research grant support from Edwards Lifesciences, Medtronic, Boston Scientific, and Abbott Vascular; and consulting income from Medtronic.