In cases of aortic stenosis that is still asymptomatic, intervention is not required for all patients: in most individuals, only monitoring is currently recommended. Indeed, the latest European recommendations recommend only offering surgery or percutaneous implantation (Tavi) in two situations: in the face of severe aortic stenosis affecting left ventricular function, or in the face of narrowing that becomes symptomatic with exercise. “The management of asymptomatic severe aortic stenosis is controversial,” underlines the European Society of Cardiology (ESC).
In patients with preserved LVEF
Two studies published in October, however, evaluate the benefit of early intervention in asymptomatic patients. Starting with those with asymptomatic severe aortic stenosis with preserved left ventricular ejection fraction (LVEF).
In the first, 901 people affected by this type of disorder – on average 75.8 years old, with an overall STS score predictive of mortality risk of 1.8% and a low surgical risk for 84% – were recruited in 75 centers. North Americans (1). These participants were randomized to either early intervention with Tavi, with transfemoral balloon expandable valve placement, or simple clinical monitoring, and were followed for a median of 3 ,8 years old.
The results suggest that “the early Tavi strategy was superior to clinical monitoring in reducing the incidence of death, stroke and unplanned cardiovascular hospitalizations”. Indeed, the main endpoint, a composite criterion including these three elements (incidence of deaths, strokes and unscheduled hospitalizations due to cardiovascular causes), occurred in more than 45% of patients who were simply followed, but only in 27 % of those who received early intervention.
In fact, this difference was mainly due to unplanned hospitalizations avoided, since only 21% of patients who had a Tavi had to go to the hospital unscheduled for a cardiovascular cause, compared to nearly 42% of participants in the surveillance group. . Concerning strokes and deaths, a smaller difference was observed since, among patients who had early Tavi, 4.2% suffered a stroke (compared to 6.7% in the surveillance arm), and 8.4% died. (compared to 9.2% of patients simply monitored).
Additionally, most (87%) patients in the surveillance group ultimately received Tavi later in follow-up. Also, the adverse effects appeared similar in the two groups.
Conflicting results in patients also suffering from myocardial fibrosis
A second clinical trial, called Evolved, looked at the benefit of early intervention in patients again presenting asymptomatic severe aortic stenosis, but also myocardial fibrosis (2). In practice, 224 patients aged 73 on average and presenting this type of disorder were recruited in Australia and the United Kingdom. These patients were randomized either to be simply monitored or to receive early intervention with percutaneous or surgical valve replacement — another difference from the previous study.
The main endpoint also concerned deaths from all causes and unplanned hospitalizations from cardiovascular causes – but only those linked to aortic stenosis. Additionally, the incidence of stroke was not included in this composite outcome.
And, this time, the authors conclude that a “ Early aortic valve intervention has no proven effect on all-cause mortality or unplanned hospitalizations related to aortic stenosis ». This is despite the fact that the primary endpoint occurred in 23% of patients in the surveillance group, compared to 18% in the interventional arm: a non-significant difference. And for good reason, as the publication specifies, “The trial had a wide 95% confidence interval. »
Fewer symptoms and fewer hospitalizations also in cases of myocardial fibrosis?
If the death rate appeared equivalent in the two groups (14% in the interventional arm, 13% in the surveillance group), on nine secondary endpoints, two nevertheless suggest that early intervention could prove superior to simple monitoring. In fact, hospitalizations appeared almost three times more frequent in the surveillance group (17% of patients hospitalized unexpectedly due to their stenosis) than in the interventional group (6% of patients hospitalized). Additionally, according to the article, “early intervention was associated with a lower rate of NYHA class II-IV symptoms than the conservative strategy at 12 months (OR = 0.37)”.
(1) Philippe Généreux et al. Transcatheter Aortic-Valve Replacement for Asymptomatic Severe Aortic Stenosis. NEJM. Published October 28, 2024
(2) Krithika Loganath et al. Early Intervention in Patients With Asymptomatic Severe Aortic Stenosis and Myocardial FibrosisThe EVOLVED Randomized Clinical Trial. JAMA. Published October 28, 2024
