Early intervention with TAVR proves safe and effective for asymptomatic aortic stenosis

The first powered randomized trial examining early intervention with transcatheter aortic valve replacement (TAVR) in patients with asymptomatic, severe aortic stenosis (AS) found this strategy to be both a safe and effective alternative to clinical surveillance (CS).

Findings were reported today at TCT 2024, the annual scientific symposium of the Cardiovascular Research Foundation (CRF). TCT is the world's premier educational meeting specializing in interventional cardiovascular medicine. Results were also published simultaneously in the New England Journal of Medicine.

For patients with asymptomatic, severe AS and preserved left-ventricular ejection fraction, current guidelines recommend clinical surveillance every six to 12 months. Whether the strategy of early TAVR confers benefits over guideline-indicated clinical surveillance remains to be determined.

From March 2017 through December 2021, 1,578 patients consented for screening at 75 centers in the United States and Canada. A total of 901 patients were randomized to either transfemoral TAVR (n=455) or clinical surveillance (n=446). The mean age was 76 years, 69% were male, the mean Society of Thoracic Surgeons risk score was 1.8%, and 84% of patients were considered low surgical risk per local heart team evaluation. Asymptomatic status was confirmed in more than 90% of patients with a negative treadmill stress test. In addition, the mean Kansas City Cardiomyopathy Questionnaire score at baseline was 92.7 (excellent status). Baseline echo characteristics were also similar between both groups.

The primary endpoint, the composite of death, stroke, or unplanned cardiovascular hospitalization, was evaluated for superiority in the intent-to-treat population after a minimum follow-up of two years. Early TAVR resulted in a significant reduction of the primary endpoint at two years as well as a median follow-up of 3.8 years, occurring 35.1% in the TAVR group compared with 51.2% in the surveillance group [HR (95%CI): 0.50 (0.40, 0.63), p < 0.001]. 

The secondary endpoint of favorable health status outcome occurred more frequently in the early TAVR group (86.6%) compared with the surveillance group [68.0%, Abs ∆: 18.5% [12.6%, 24.3%], p <0.001]. 

Left-ventricular and left-atrial health at two years was also better for those who underwent early TAVR [48.1% versus 35.9%, Abs ∆: 12.2% (4.4%, 19.4%), p=0.001]. Change in left-ventricular ejection fraction from baseline to two years, new onset atrial fibrillation, and death or disabling stroke were similar between the two groups. 

By two years, more than 70% of the patients in the clinical surveillance group had AVR, with the vast majority becoming symptomatic. The median time to conversion was 11.1 months, with 26% and 47% requiring AVR at 6 months and 1 year, respectively. More importantly, ~40% of patients from the clinical surveillance group presented with acute and advanced signs and symptoms, such as NYHA III-IV heart failure, pulmonary edema, or syncope.

Given the benefits observed and the lack of harm, early TAVR may be preferred to clinical surveillance in patients with asymptomatic severe AS, especially when combined with the challenges of timely symptom recognition and prompt treatment in real-world settings. Not only is early intervention safe and effective, but it also prevents a decline in quality of life for those who later receive TAVR and could prevent the development of cardiac damage."

Philippe Généreux, MD, Director of the Structural Heart Program at the Gagnon Cardiovascular Institute at Morristown Medical Center

The study was funded by Edwards Lifesciences.