乌鸦传媒

Transcatheter aortic valve replacement (TAVR) got some preliminary affirmation for asymptomatic or minimally symptomatic severe aortic stenosis in a retrospective registry study.

Of participants who got elective TAVR, the one in five who had minimal symptoms before the procedure tended to have good outcomes that compared favorably against the majority of more symptomatic peers:

• Fewer 30-day composite adverse events (death, stroke, major or life threatening/disabling bleeding, acute kidney injury stage III, new dialysis, or moderate/severe paravalvular leak): 8.1% vs 9.9% (adjusted OR 0.95, 95% CI 0.92-0.99)
• Fewer deaths at 1 year: adjusted HR 0.70 (95% CI 0.66-0.75)
• More people alive and well at 1 year: OR 1.19 (95% CI 1.16-1.23)

Additionally, for those less sick individuals, symptoms and quality of life assessed by the Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OS) was 86.4 points at baseline and increased by 2.7 points at 30 days and 3.8 points at 1 year, reported researchers led by Chetan Huded, MD, MSc, of Saint Luke's Mid America Heart Institute in Kansas City, Missouri, in .

TAVR is well established for severe aortic stenosis patients with symptoms, whereas it is considered reasonable to delay in people without symptoms.

Huded's group concluded that "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."

To that end, the authors suggested that the trial -- recently having completed enrollment of 901 asymptomatic patients randomized to Sapien TAVR or clinical surveillance -- is anticipated to provide important answers.

A large, well-conducted randomized trial would be needed to prove that TAVR really helps minimally symptomatic patients, agreed Charanjit Rihal, MD, MBA, of Mayo Clinic, Rochester, Minnesota, writing in an .

"The data show we are likely not hurting patients by providing TAVR to minimally symptomatic patients, but that is not enough. We need to demonstrate we are actually helping them," Rihal stressed. "There are good theoretical reasons for thinking we are: possibly a lower risk of sudden death, we can clear patients to exercise, and so on, but we can't claim we are helping them unless we can prove it."

According to registry records, the proportion of minimally symptomatic TAVR patients is already on the rise, going from approximately 12% in 2015 to nearly 25% in 2021. There is wide variability in the proportion of minimally symptomatic patients treated by site, with some centers having these patients make up as little as less than 10% of TAVR cases, and others exceeding 50%, Huded's group showed.

Outside of severe aortic stenosis, there are also efforts to bring TAVR to another pool of patients early in the disease process: those with moderate, calcific aortic stenosis. In the ongoing 750-person randomized trial, investigators plan to evaluate outcomes of Sapien TAVR vs surveillance alone in this group.

For their retrospective study of asymptomatic or minimally symptomatic severe aortic stenosis, Huded and colleagues relied on The Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) Transcatheter Valve Therapies (TVT) registry and included people who got elective TAVR from 2015 to 2021. Eligibility criteria included an aortic valve area <1.0 cm² and relatively normal left ventricular ejection fraction (LVEF), indicative of people who could have reasonably been followed with watchful waiting instead of undergoing TAVR.

Among 231,285 participants (median age 80 years, 47.5% women), 20% were minimally symptomatic before TAVR, as determined by a KCCQ-OS score ≥75.

People with or without severe symptoms shared similar disease severity (by mean aortic valve gradient and area and LVEF).

However, the minimally symptomatic minority included more men (61.2% vs 50.3%) and tended to have a lower burden of major comorbidities. Median STS predicted risk of mortality was 3.2% among minimally symptomatic individuals vs 4.2% in the more symptomatic.

People with moderate or severe symptoms had KCCQ-OS increases of 32.2 points at 30 days and 34.9 points at 1 year from a baseline 42.4 points.

Besides the lack of controls in the study, Huded's group acknowledged the possibility of unmeasured confounding and the lack of core laboratory adjudication of aortic stenosis severity.

Comment