Transcatheter aortic valve replacement (TAVR) in asymptomatic and minimally symptomatic patients is associated with a high survival rate, but relatively minor improvements, according to new research published in JACC: Cardiovascular Interventions.[1] The question clinicians still need to answer is whether or not these patients should be treated with TAVR in the first place.
“In the current era, the procedural risks and postprocedural recovery after TAVR are more favorable compared with those after surgical aortic valve replacement,” wrote Chetan P. Huded, MD, a cardiologist specializing in structural heart disease with Saint Luke’s Mid America Heart Institute in Kansas City, Missouri. “Given this more favorable profile of procedural risk, coupled with observational studies suggesting increased mortality associated with severe aortic stenosis (AS), even in asymptomatic patients, there is growing interest in earlier timing of TAVR. A key insight needed to better understand the risks and benefits of this approach is a deeper understanding of the outcomes of TAVR in asymptomatic or minimally symptomatic patients with severe AS.”
Huded and colleagues examined data from more than 230,000 TAVR patients treated from 2015 to 2021. The median patient age was 80 years old. All data came from the STS/ACC TVT Registry.
A patient was categorized as being minimally symptomatic if their Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score fell below 75. Based on current guidelines, the authors wrote, these patients “could have been reasonably followed with clinical surveillance rather than treated with TAVR.”
Overall, 20% of patients treated with TAVR were minimally symptomatic. The number of minimally symptomatic patients undergoing TAVR increased as time went on. There was no relationship between a facility’s TAVR volume and its likelihood of treating a minimally symptomatic patient with TAVR.
While all TAVR patients showed “statistically significant improvements in health status” after treatment, minimally symptomatic patients saw mean improvements in KCCQ-OS of just 2.7 points at 30 days and 3.8 points after one year. Among patients with moderate or severe symptoms, on the other hand, the mean improvements in KCCQ-OS were 32.2 points at 30 days and 34.9 points after one year.
Minimally symptomatic TAVR patients were linked to lower rates of 30-day adverse events, 30-day mortality and one-year mortality than patients with moderate or severe symptoms. According to the authors, one possible reason for this trend is that patients with fewer symptoms have “less extensive cardiac damage.”
“Treating patients before the onset of significant symptoms may reduce the potential for progressive cardiac damage, thereby improving the safety of the procedure and the chance for favorable long-term outcomes,” they wrote.
In addition, the authors added, minimally symptomatic patients were linked to a shorter median length of stay (1 day) than patients with moderate or severe symptoms.
“AS is a progressive disease, and without treatment, minimally symptomatic patients are expected to become more symptomatic over time,” the authors wrote. “In a historical cohort of 622 patients with asymptomatic severe AS, the probability of remaining symptom free was 82% at 1 year, 67% at 2 years, and 33% at 5 years’ follow-up. In light of these historical data, the results of our study support the hypothesis that TAVR in minimally symptomatic patients may be beneficial to prevent the anticipated deterioration of health status, although without a comparison with nontreated patients, this hypothesis cannot be formally tested.”
The team concluded its study by emphasizing again that more research was still necessary.
“The outcomes of these patients with a conventional strategy of surveillance followed by TAVR at the onset of major symptoms were not evaluated in this study,” they wrote. “Results of ongoing randomized clinical trials are needed to confirm the safety and effectiveness of TAVR in minimally symptomatic or asymptomatic patients with severe AS.”
Interventional cardiologist weighs in on TAVR for minimally symptomatic patients
Interventional cardiologist Charanjit S. Rihal, MD, chair of cardiovascular medicine with Mayo Clinic, wrote a commentary about the study’s results that was also published in JACC: Cardiovascular Interventions.[2]
Rihal praised Huded’s team for providing helpful data and raising “important questions.” He added that it makes sense long-term survival was higher in patients who presented with fewer symptoms. What remains unclear, however, is what cardiologist should take away from these findings.
“How do we interpret the results? Do these results indicate we ought to recommend TAVR for even minimally symptomatic patients with severe AS? These questions remind one of the classic debates in the era when open surgery was the only real treatment for AS,” Rihal wrote. “Giants of cardiology would pummel each other on the podium, arguing one way or the other, with the main arguments being ‘what are we waiting for?’ vs. ‘surgery is the main cause of sudden death in asymptomatic AS.’”
Improving a patient’s symptoms or quality of life are arguably the best reason to perform any procedure, he said. This analysis showed that TAVR did have that impact on minimally symptomatic patients, but the improvements were relatively minor. Would survival have been just as high among these patients if they had not undergone TAVR? Could it have been even higher? These are just some of the questions researchers need to continue asking as time goes on.
“The data show we are likely not hurting patients by providing TAVR to minimally symptomatic patients, but that is not enough,” Rihal wrote. “We need to demonstrate we are actually helping them.”
He concluded by saying additional research needs to include a control group of minimally symptomatic patients treated without TAVR.
“Because 20% of the near quarter million patients enrolled over just seven years in the registry had minimal symptoms, the investigators also demonstrate there are more than enough patients to conduct such a study, and to conduct it rapidly,” he wrote.
Click here to read the full study from Huded et al.
Click here to read Rihal’s editorial comment in full.
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.