TAVR still beneficial for very low LVEF, lack of contractile reserve

The severity of left ventricular dysfunction at baseline didn’t appear to impact survival after transcatheter aortic valve replacement (TAVR) in a substudy of patients with low-flow, low-gradient (LFLG) aortic stenosis, suggesting TAVR is an acceptable treatment in this high-risk population.

In fact, left ventricular ejection fraction (LVEF) increased more following TAVR in patients with baseline values below 30 percent—a mean 11.9 percent increase one year later compared to a 3.6 percent increase among those with starting LVEFs between 30 and 40 percent. Survival wasn’t significantly different at 30 days or a median 23 months of follow-up based on patients’ initial LVEF.

Another key finding of the research was that a lack of contractile reserve detected via preprocedural dobutamine stress echocardiography (DSE) appeared to have little effect on clinical outcomes or future changes in LVEF.

“Per these results, patients with LFLG AS (aortic stenosis) should not be declined for TAVR on the basis of left ventricular dysfunction severity or dobutamine stress echocardiography results,” lead author Frederic Maes, MD, PhD, with Quebec Heart & Lung Institute, and colleagues wrote in JAMA Cardiology. “TAVR appears to be a good alternative treatment for patients with LFLG AS and severe left ventricular dysfunction.”

The TOPAS-TAVI registry substudy included 293 patients with LFLG aortic stenosis, defined as a mean transvalvular gradient less than 35 mm Hg, an effective orifice area less than 1.0 cm2, and an LVEF of 40% or less. Patients were then divided into two groups according to baseline LVEF—43.7 percent of the cohort had very low LVEF (below 30 percent), while the rest of the patients had low LVEF (between 30 and 40 percent).

At a median follow-up of 23 months, 44.5 percent of patients in the very low LVEF group had died compared to 45.5 percent in the low LVEF group. That difference was statistically insignificant, but nevertheless reflects the “high-risk profile of this population,” Maes and coauthors noted.

Still, the improvement in LVEF in both groups provides reassurance that TAVR is an appropriate intervention for these patients, the researchers said.

“These results support TAVR for LFLG AS, irrespective of the severity of left ventricular dysfunction and DSE results,” they wrote.