Valve Hemodynamic Deterioration Post-TAVR Is Rare, Not Linked With Adverse Cardiovascular Outcomes

CHICAGO, IL—The incidence of valve hemodynamic deterioration is approximately 2% at both 30 days and 18 months among patients undergoing transcatheter aortic valve replacement, but the changes in the mean aortic-valve gradient do not translate into an increased risk of death, stroke, or need for reintervention, according to researchers.

Sreekanth Vemulapalli, MD (Duke Clinical Research Institute, Durham, NC), who presented the data this week at the American College of Cardiology 2016 Scientific Sessions, said the findings are reassuring, at least for now.

“I think that’s one of the key aspects of our study,” he told TCTMD. “We don’t see an association with clinical events when you have this increase in gradient. I think that is very reassuring. Now, we will have to follow patients out much longer to understand if that means, over time, the valve might need to be replaced. When you look at the data in surgical valves, we have data for 20 years. TAVR has not been around that long, but up to 18 months, it looks good.”

Concerns about the potential for valve deterioration are not entirely new. In 2014, for example, the PORTICO-IDE (Portico Resheathable Transcatheter Aortic Valve System US investigational device exemption) trial was temporarily halted by study sponsor St. Jude Medical because of an unexpected finding of reduced leaflet motion in a subgroup of patients.

In October, Raj Makkar, MD (Cedars-Sinai Medical Center, Los Angeles, CA), and colleagues published an analysis of clinical and registry data showing reduced leaflet motion as detected by 4D computed tomography following the implantation of bioprosthetic valves. In their analysis of the PORTICO-IDE study, reduced leaflet motion was observed in 16 of 37 patients who received the Portico valve and six of 14 patients who received the Sapien XT valve (Edwards Lifesciences).

The reduced leaflet motion was determined to be “hemodynamically subclinical” at the time of detection, according to Makkar and colleagues, with patients having normal aortic-valve gradients on echocardiography. A pooled analysis of data from RESOLVE and SAVORY—each a single-center registry of patients with newly implanted aortic valves—confirmed the leaflet abnormalities and suggested a higher incidence of stroke or transient ischemic attack in individuals with reduced leaflet motion. The impaired leaflet motion was not detected on transthoracic echocardiography.

“Really, to see thrombosis, you need advanced imaging techniques like CT or transesophageal echocardiography,” said Vemulapalli. “Sometimes we use transthoracic echocardiography, which is not really that good at finding thrombi. What you can measure with transthoracic echocardiography is the gradient across the valve, and that is thought to be a surrogate. There are several possible causes for a gradient to be high, one of which is thrombosis.”

Data From the TVT Registry

Using data from the Society of Thoracic Surgeons/American College of Cardiology TVT Registry, the researchers assessed valve hemodynamic deterioration in short-term and long-term cohorts of patients undergoing TAVR between 2011 and 2015. In the short-term cohort, investigators assessed outcomes following 10,099 TAVR procedures in individuals who underwent postprocedure and 30-day transthoracic echocardiography. The long-term cohort included 3,175 TAVR patients who underwent echocardiography at 30 days and 1 year.

At 30 days, 2.1% of patients had valve hemodynamic deterioration, defined as an increase in the aortic-valve gradient ≥ 10 mm Hg. At 18 months, the incidence of hemodynamic deterioration was 2.5%. When mortality was included, the incidence of death/hemodynamic deterioration was 7.1% and 23.5% at 30 days and 18 months, respectively.

Despite these changes, when researchers assessed clinical outcomes, which they were able to do via linkage between the TVT Registry and Centers for Medicare & Medicaid Services database, they observed no significant difference in the combined endpoint of death, stroke, or need for aortic-valve reintervention between patients with valve hemodynamic deterioration and those without. In addition, there was no signal of risk when individual endpoints, including MI and heart-failure hospitalization, were assessed.

In terms of predicting valve hemodynamic deterioration, male sex, higher body mass index, severe chronic lung disease, higher baseline mean aortic-valve gradients, valve-in-valve procedures, smaller valve size, and severe patient-prosthesis mismatch were all associated with increased risk. In the long-term, the use of factor Xa inhibitors and the presence of higher pressure gradient at discharge were associated with an increased risk of hemodynamic deterioration.

Speaking during the ACC session, Vemulapalli noted that the definition of valve hemodynamic deterioration is not yet validated, which means the incidence might be underestimated if clinicians rely solely on the change in the aortic-valve gradient between two time points. Such a definition does not take into account deaths that might have occurred in between those measurements, nor does it take into account aortic-valve reinterventions.   

“The issue becomes more important as we go into lower-risk patients,” he told TCTMD. “If you have a very high-risk patient who has no option other than TAVR, you do the best you can do. When you start thinking about TAVR in patients who might actually be able to get surgical valves, where we have 20 years of experience, now the issue [of valve hemodynamic deterioration] becomes very important. We know these patients are going to live for a while and we want to make sure when we say you can have TAVR or a surgical valve, we’re giving them an equal choice.”

Recently, as reported by TCTMD, investigators evaluated more than 1,500 patients participating in a multicenter registry and reported the incidence of subclinical valve hemodynamic deterioration—also defined as at least a 10-mm Hg increase in mean gradient between discharge after TAVR and the last follow-up—was documented in 4.5% of patients, including 2.8% of patients in the first year.

Related Stories:

• Subclinical Changes in Valve Hemodynamics Observed in TAVR Patients
• Reduced Leaflet Motion in Bioprosthetic Aortic Valves Not Uncommon But Remedied by Anticoagulation