SAN DIEGO – Severe prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) increases risk of adverse outcomes and may be preventable in some cases with careful preprocedural planning, suggests a registry-based retrospective cohort study of 62,125 patients treated in the contemporary era.
The study – the largest to date of this patient population – determined that about one in every eight patients undergoing TAVR ultimately had a severe mismatch between the hemodynamics of the valve prosthesis and the requirements for cardiac output. Compared with counterparts that have moderate or no PPM, these patients with severe PPM had a 12% higher adjusted risk of heart failure rehospitalization and a 19% higher adjusted risk of death, according to results reported at the Transcatheter Cardiovascular Therapeutics annual meeting and simultaneously published online (J Am Coll Cardiol. 2018 Sep 23.).
Notably, some of the predictors of severe PPM, such as use of smaller-diameter valves and performance of a valve-in-valve procedure, were potentially modifiable.
“Our findings suggest that efforts should be made to identify this problem and limit the risk for PPM after TAVR,” concluded lead investigator, a professor at the University of Pennsylvania and director of the cardiac catheterization laboratories, Hospital of the University of Pennsylvania, both in Philadelphia. “Awareness is really the first step in trying to fix it.”
“We spend a lot of time in the heart-team meetings looking at the CT scans for annular dimensions and the vascular access, but we don’t really talk too much about severe PPM or the risk of that,” he elaborated. “This [study] allows us to start to predict it, based on patient factors and what prosthesis we might be choosing for a patient, and it allows us to have that conversation and think about alternatives.
“There are alternatives to try to avoid PPM, everything from which prosthesis we choose to the size of the prosthesis, to whether we fracture a patient’s valve if we are doing a valve-in-valve procedure. In the future, in some situations, we might even choose a low-risk or low-intermediate-risk patient for surgery with an enlargement operation in order to get a larger effective orifice area. So there are choices that we can make, and we should start thinking about that in the heart-team approach.”