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An assessment of alcohol septal ablation (ASA) effects is reasonably performed at least up to 1 year after the procedure. After this period some patients have a persistence of the left ventricle outflow tract (LVOT) obstruction. Management of such cases is still unclear. Since the introduction in a practice, ASA looks as a promising alternative to surgery.
To assess safety and effectiveness of repeated alcohol septal ablations for a residual LVOT obstruction by an enormous septal bulge in patients with hypertrophic cardiomyopathy (HCM).
Since 2000 up to now 168 ASA were done in a single center. 22 patients underwent secondary (repeated) ASA due to the residual obstruction of LVOT and severe heart failure symptoms with an optimal medical therapy. Mean age was 47.3 (18.6) years. Median of the peak-to-peak invasive gradient was 76 mmHg at rest (interquartile range - 100 mmHg). Median of the peak-to-peak invasive gradient was 100 mmHg at an exertion (interquartile range - 160 mmHg). All patients had a sinus rhythm without the pacemaker dependence. Mean interventricular septum diameter at the level of the obstruction was 23.3 (4.6) mm. Fixed dose of an ethanol (3 ml) was infused in the target septal branch. Main success criteria for ASA procedure was 50 % reduction of an exertional gradient.
Hospital mortality was 0%. Some arrythmological disorders happened in a short-term period: Complete heart block - in 1 case, ventricular tachycardia - 1 patient (intraprocedural, managed by rapid pacing), ventricular extrasystolia - 1 patient (less 5000 per day on Holter monitor, managed conservatively). Access complications were not present. One case was complicated by inferior myocardial infarction, than ileofemoral thrombosis with submassive pulmonary embolism (this patient had a thrombophilia). After that temporary cava filter was implanted.
After procedure median of peak gradient was 10 mmHg at rest (25 percentile - 8 mmHg, 75 percentile - 27 mmHg). After procedure median of peak gradient was 80 mmHg at an exertion (25 percentile - 63mmHg, 75 percentile - 115 mmHg). Mean interventrical septum diameter at the level of the obstruction became 21.8 (5.5) mm. Clinical improvement was seen in 90.9% of cases (20/22).
Success criteria were met in 72.7% of cases (16/22).
1) Repeated (secondary) ASA in a patient with HCM and residual LVOT obstruction is safe and effective in selective cases. 2) Hospital mortality and severe arrythmological disorder were not documented. 3) Long-term results of repeated ASA need to be assessed to find a role of this procedure in a complex treatment of patients with obstructive HCM. 4) Also, future studies are needed to define optimal candidates for repeated ASA.