Aims: To analyze the impact of intra-procedural echocardiographic imaging on the interventional strategy in ethanol-induced septal ablation (PTSMA) for symptomatic hypertrophic obstructive cardiomyopathy (HOCM), based on a single-center experience of 7 years.
Methods and results: PTSMA was intended for refractory symptoms in 337 patients (pts.) with HOCM (mean age: 54 +/- 15 years), with 312 procedures completed by injection of 2.8 +/- 1.2 ml ethanol. In 25 pts. (8%) the intervention was aborted without ethanol injection, mostly because of echocardiographic findings (n = 18/6%). An echocardiography-driven target vessel change was necessary in 33 pts. (11%). In the 312 pts. who received ethanol, permanent pacing was necessary in 22 cases (7%). In-hospital mortality was 1.3% (4 pts.). After 3 months, mean NYHA functional class was reduced from 2.9 +/- 0.5 to 1.5 +/- 0.6 (p < 0.0001) along with a gradient reduction from 60 +/- 33 to 13 +/- 18 mmHg at rest, and from 120 +/- 43 to 38 +/- 35 mmHg with provocation (p < 0.0001 each). Exercise capacity improved from 94 +/- 51 to 115 +/- 43 W, peak oxygen consumption from 18 +/- 4 to 21 +/- 6 ml/kg/min (p < 0.01 each). There was no significant difference regarding residual gradients in pts. with different levels of immediate gradient reduction during probatory balloon occlusion.
Conclusions: Catheter-based septal ablation is an effective non-surgical technique for reducing symptoms and outflow gradients in HOCM. Intra-procedural echocardiographic guidance has a cumulative impact on the interventional strategy in about 15-20%, and clearly identifies pts. who should not receive ethanol but undergo a surgical myectomy.