Since it’s first FDA approval in late 2011 the use of transcatheter aortic valve replacement therapy (TAVR) has grown dramatically– but not dangerously or explosively– in the US. Now accumulating data from a central national registry provides the best picture yet of the evolution and current status of TAVR.
The TVT Registry, which is run by the Society of Thoracic Surgeons (STS) and The American College of Cardiology (ACC), was launched in response to early concerns that excessive enthusiasm for TAVR might cause a stampede of inappropriate usage. In order to obtain Medicare reimbursement for TAVR hospitals were required by CMS to participate in the registry. Three year results from the registry covering 2012 through 2014 were published on Monday in the Journal of the American College of Cardiology and the Annals of Thoracic Surgery.
The new data shows that TAVR has been “a good option” for the right patients, said Frederick Grover (University of Colorado in Denver), in a press release from the ACC and STS.
The report contains data on 26,414 TAVR procedures. Less than 5,000 procedures were performed in the first year, with the number more than doubling in each of the two successive years. (It should be noted that the registry does not include the estimated 10,000 patients who received TAVR as part of FDA required investigational device exemption trials.)
In an accompanying editorial Michael Reardon, MD, and Neal Kleiman (Houston Methodist DeBakey Heart & Vascular Center) write that “patient outcomes remain extremely encouraging,” citing the rates of procedural success (97.4%), mortality (4.4%), and other clinical outcomes. Only 1.3% of procedures convert to open surgery.
In the first year 156 sites participated in the registry. This grew to 348 in 2014. The authors report there are now more than 400 participating sites.
Over the three years there was a small but statistically significant reduction in the level of baseline risk in the TAVR patient population, but throughout the period TAVR patients were clearly high risk by nearly any measure. TAVR patients were 82 years old in the first two years of the study and 81 in the last year. Patients had multiple comorbidities and were highly symptomatic and frail.
About 90% of procedures were performed in hybrid operating room suites. The authors speculate that in the future more procedures may be performed in catheterization labs, as catheter sizes decrease and as operators grow more comfortable using moderate sedation instead of general anesthesia.
The most common intraprocedural cardiac complication was implantation of a new pacemaker in about 10% of patients. New onset atrial fibrillation occurred in about 7% of patients. One of the most feared complications, stroke, was adjudicated in 2% of patients. Length of hospital stay, 6.2 days in 2014, has been growing shorter and is expected to continue to decline. Two-thirds of patients are discharged to their home, which the authors termed “an important finding.”
In their editorial Reardon and Kleiman write that the results, although very positive, do not completely alleviate “early concern about ‘creep’ of the procedure into inappropriately low-risk patient populations.” In addition, they note that complications may emerge with longer term followup, since “structural valve degeneration can become apparent fairly abruptly after” five years.
Another important finding is that TAVR is underutilized in black patients, as less than 5% of TAVR patients were black. “Information like this would have been unknown to us before, but because the Registry data were published, we know about the issue and can more easily address it in clinical practice,” said David Holmes (Mayo Clinic), in the press release.
Commenting on the paper, Rick Lange (Texas Tech University Health Sciences Center), a member of the FDA advisory panel that first evaluated TAVR, offered strong support for the registry’s “novel approach to post-market surveillance”:
“The TVT registry provides a window into the evolving technology of TAVR and clinical practice patterns and patient outcomes in the U.S. This information wouldn’t be available without the close collaboration of the Society of Thoracic Surgeons (STS), the American College of Cardiology (ACC) and Center for Medicare & Medicaid Services (CMS) in providing a robust data repository that captures nearly all commercially funded TAVRs in the United States. This novel approach to post-market surveillance will provide scientific data throughout the full product life cycle of emerging TAVR technology and inform improvements in the procedure, patient selection, and outcomes.”