STS/ACC TVT Registry Shows Real-World TAVR Results Are Consistent With Clinical Trials

March 31, 2014—David R. Holmes, MD, presented 1-year outcomes from the Society of Thoracic Surgery/American College of Cardiology (STS/ACC) Transcatheter Valve Therapy (TVT) Registry at the ACC.14: 63rd annual scientific session of the American College of Cardiology being held in Washington, DC. The US National TVT Registry is a collaboration of the STS, ACC, Centers for Medicare and Medicaid Services, and the US Food and Drug Administration.

According to the ACC, this registry is the first to provide 1-year outcomes data of nearly all patients in the United States undergoing transcatheter heart valve replacement (TAVR). The data show that real-world outcomes are comparable to or slightly better than those found in clinical trials. However, the study investigators advised that specific baseline characteristics of patients undergoing TAVR are associated with differing degrees of death and survival and may be important considerations for patient counseling and shared decision making about the procedure.

The ACC noted that with the diffusion of TAVR from research to practice, there has been some concern that patients undergoing this procedure in clinical trials may fare better than those in real-world settings. Although in-hospital outcomes for TAVR in clinical practice in the United States are consistent with those in landmark clinical trials, little is known about longer-term results.

In the study, the investigators evaluated 1-year outcomes of TAVR among Medicare patients by reviewing data from the TVT Registry linked with Medicare claims data.

The registry, which was developed to track patient safety and outcomes related to TAVR, collects and reports data on patient demographics, procedure details, facilities, and physicians.

The investigators reviewed outcomes data for 5,980 patients across 224 sites at 1 year after TAVR. They found that outcomes were similar to those in randomized controlled trials. Based on the TVT Registry data, the in-hospital death rate was 5.3%, and the in-hospital stroke rate was 1.7% at the time of the TAVR procedure.

At approximately 6 months after TAVR, a vast majority of patients who had successful procedures were still living and avoided repeat hospitalization. At 1 year after the procedure, 26.2% of patients had died and 3.6% had experienced a stroke.

Dr. Holmes, the study’s lead investigator and Past President of the ACC, is Scripps Professor of Medicine at the Mayo Clinic in Rochester, Minnesota.

In the ACC announcement, Dr. Holmes commented, “Regulatory agencies have been incredibly concerned over what happens when you open high-risk technology to broader groups of patients, physicians, and medical centers. These data are comforting in that we went from a relatively small number of clinical trial participants receiving TAVR in a few expert medical centers to a relatively large number of real-world patients in over 200 clinical settings with very similar results.”

The TVT Registry investigators also found that specific factors were associated with the incidence of death and stroke including gender, age, and kidney function. The older a patient was at the time of TAVR, the higher the death rate. Patients younger than 75 years had a mortality rate of 21.5% compared with patients older than 95 years, who had a 31.9% mortality rate. Stroke did not show the same degree of relationship with age. Men had higher mortality rates than women, but women had higher rates of stroke. The disparity was a surprise to investigators and will be the focus of subsequent studies, according to Dr. Holmes.

Patients with abnormal kidney function, particularly those on dialysis, were also at higher risk of stroke and death. Patients with chronic obstructive airway disease had worse outcomes in terms of death but little difference in stroke rates compared to other patients.

“By virtue of identifying factors associated with stroke and mortality, we now have data that we can use for developing tools in terms of risk prediction models so we can better educate patients and families in terms of making good, important decisions about their treatment options,” stated Dr. Holmes. “We can also educate physicians to appropriately communicate the risk-benefit ratio to patients, which is hugely important as we move toward the concept of shared decision making in health care.”

As summarized by the ACC, the registry data were available for 5,980 patients over age 65 with Medicare insurance fully linked to Administrative Claims Centers for Medicare and Medicaid Services data at 1 year. Median age was 85 years. The STS predicted operative mortality score was 7.1.

Of those patients included in this study, 83.6% were classified as NYHA III/IV, 12.8% had a previous stroke, 31.1% had peripheral arterial disease, and 15.2% had oxygen–dependent lung disease. The investigators noted that the characteristics of the patient population were similar to patients treated in randomized controlled trials.

According to Dr. Holmes, the study has demonstrated that administrative claims data can be successfully linked with a national registry. He said that registries will assume increasing importance for postmarket surveillance and postapproval studies that assess the safety and efficacy of high-risk medical technology and procedures.