TAVR UNLOAD Trial: TAVI in HFrEF Patients With Moderate AS

The TAVR UNLOAD trial, presented by Nicolas Van Mieghem, MD, PhD from Erasmus University Medical Center, explored the benefits of Transcatheter Aortic Valve Replacement (TAVI) in patients with heart failure with reduced ejection fraction (HFrEF) with LVEF 20 to 50% and moderate aortic stenosis (AS). The trial results suggest that performing TAVI early in moderate AS does not offer significant clinical improvements over surveillance until AS becomes severe. While TAVI was found to be safe, it did not improve survival or other key clinical outcomes, reinforcing the current guideline recommendation to delay TAVI until AS reaches a severe level.

Quality of Life and Disease Progression
Quality of life (QoL) gains, as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ), initially favored TAVI through the first year. However, these gains diminished over time as more patients in the surveillance group progressed to severe AS and received TAVI. The early KCCQ advantage seen in the TAVI group disappeared by two years, demonstrating no sustained impact on survival or hospitalization rates between the groups.

Guideline Adherence and Selective Early Intervention
Van Mieghem emphasized that for most HFrEF patients, waiting until AS becomes severe remains a sound approach. He highlighted that only a select group of patients with particularly challenging symptoms might benefit from a preemptive TAVI. A heart failure specialist suggested that when faced with moderate AS in HFrEF patients, clinicians should carefully confirm AS severity—potentially through dobutamine stress echocardiograms or CT scans—to avoid premature TAVI based on misclassified AS severity. The specialist added that thorough diagnostic measures help ensure that patients receive appropriate intervention timing.

Future Directions
One heart failure expert pointed out that TAVR UNLOAD results could support a Class IIb recommendation in future guidelines, suggesting TAVI as an option in certain HFrEF patients who have difficulty with frequent follow-up and medication adjustments due to AS. Van Mieghem shared that the study’s original aim was to investigate whether TAVI could support afterload reduction in heart failure patients. He noted that future research could explore preemptive TAVI in patients with asymptomatic severe AS or in specific patient phenotypes with moderate AS, as these groups may experience different benefits.

Arguments For and Against TAVI in Moderate AS

• For TAVI: Improvements in quality of life within the first year, a favorable safety profile with minimal complications, and potential benefit in cases where symptoms are challenging to control.
• Against TAVI: Lack of significant improvement in survival or hospitalization rates, the transient nature of quality of life gains, a high crossover rate due to faster-than-expected AS progression in the surveillance group, and the need for additional research to refine optimal timing and patient selection.

In summary, the TAVR UNLOAD trial upholds current guidelines, suggesting that delaying TAVI in moderate AS patients with HFrEF until AS progresses to severe is generally advisable. However, specific cases may warrant earlier intervention. Ongoing trials, such as PROGRESS and EXPAND II, are expected to provide further insights, particularly regarding TAVI’s role in AS with preserved ejection fraction.

Presented at TCT 2024