Endocardial Radiofrequency Septal Ablation (ERASH) to prevent dynamic intraventricular obstruction before TAVI

ABSTRACT

BACKGROUND: Dynamic intraventricular obstruction ("suicide ventricle") is a rare but often dramatic complication that may occur in pts undergoing TAVI. Sudden abolition of cardiac afterload determined by aortic stenosis (AS) relief after TAVI could lead to paradoxical hemodynamic collapse due to increase of intraventricular gradients (IVG) and SAM. Predictive factors may include small LV diameters, asymmetrical hypertrophy with a septal bulge, high EF with elevated aortic gradients or concomitant hypertrophic cardiomyopathy (HOCM). ERASH consists in radiofrequency applications to septal portions of the left ventricular outflow tract using therapeutic electrophysiology catheters (EC), and has been successful in HOCM both as first-line procedure or after failed myectomy. We described our initial experience with ERASH before TAVI in pts deemed at risk of suicide ventricle. METHODS: Single-center, observational study with consecutive pts with symptomatic AS - mean transaortic gradient > 40 mmHg and valve area < 1.0 cm2 - and concomitant, echocardiographic findings of IVG > 30 mmHg at rest, with septal wall thickness > 15 mm. After multidisciplinary discussion, pts were considered too high-risk for combined SAVR and myectomy, and ERASH before TAVI was proposed. ERASH was performed using general anesthesia, and transeptal access were selected to prevent potential risks of crossing calcified, aortic valves with EC. RESULTS: From Jun/20 to Jun/23, 4 pts were identified (female in 75%, mean age of 76 ± 7 years; 50% with hypertension and 25% with chronic renal failure). At baseline, mean IVG at rest was 46,5 ± 22.3 mmHg, and mean transvalvular gradient was 58 ± 7.7 mmHg. After ERASH, there was a significant reduction (>50%) of IVG at rest in all patients (from 46,5 ± 22.3 to 15.5 ± 4.9 mmHg). All pts underwent TAVI with a balloon-expandable (n=3) or self-expandable (n=1) after a mean interval of 56.7 ± 35.9 days, and mean transaortic gradient was 7.7 ± 2.4 mmHg. After 30 days, all pts were in NYHA class < II with improved quality of life. CONCLUSIONS: In this initial experience, a careful pre-procedure echocardiographic assessment identified pts with concomitant AS and significant IVG at rest. ERASH before TAVI was safe and effective, and can be an adjunt intervention to prevent sudden, dynamic intraventricular obstruction in this challenging clinical presentation.