Septal ablation in Hypertrophic Cardiomyopathy Charles Knight London Chest Hospital Advanced Angioplasty 2003

Terminology Non-surgical septal reduction (NSSR) Percutaneous transluminal septal myocardial ablation (PTSMA) Transcoronary ablation of septal hypertrophy (TASH) Septal ablation Alcohol ablation HOCM ablation Sigwart procedure

History 1980’s Preliminary experiments by Ulrich Sigwart at Laussane Temporary balloon occlusion of first septal artery Injection of verapamil down first septal artery June 1994 First septal ablation by Ulrich Sigwart at Royal Brompton 1997 Described as ‘profoundly aggressive’ with an ‘unacceptably high mortality and morbidity’ in NEJM* *NEJM 1997;337:349

Myotomy-myectomy

Patient selection No evidence for effect on prognosis Majority of patients with HCM have no obstruction (~75%) Majority of patients with obstruction have symptoms responsive to medical therapy Those with obstruction and unresponsive symptoms can be treated with septal ablation or myotomy-myectomy

No effect on: Underlying pathology –Myocardial disarray –Small coronary artery abnormalities –Diastolic dysfunction Associated mitral valve abnormalities Risk of sudden death Prognosis Effect on: Outflow tract gradient Symptoms

Procedure Temporary pacing wire Intermediate wire to S1 OTW balloon inflated at origin of S1 Wire removed, balloon inflated 3-5ml of absolute alcohol injected 5 minutes marination then balloon deflated

Septal Ablation - Published Reports Knight et al Circulation 1997;95: patients Faber et al Circulation 1998;98: patients Lakkis et al Circulation1998;98: patients Gietzen et al Eur Heart J 1999;20: patients Kim et al Am J Cardiol 1999;83: patients Qin et al J Am Coll Cardiol 2001;38: patients Total237 patients Gietzen et al Eur Heart J 1999;20: patients Faber et al Heart 2000;83:32625 patients Firoozi et al Eur Heart J 2002;23: patients Shamin et al NEJM 2002 ;347: patients Total146 patients Longer term (7-36 month follow-up)

Pre Post

Effect on Outflow Gradient All reports: –65 mmHg pre –5 mmHg post Reduction in gradient sustained in long-term Shamin et al N Engl J Med 2002;347:1326

Effect on Symptoms All reports show significant improvement –Mean NYHA class pre 2.85, post 1.3 Maintained over longer-term

Effect on exercise 3 reports assessed peak O 2 consumption (n=104) –44% improvement 7 reports assessed exercise duration/watts (n=204) –41% improvement Maintained at longer- term Shamin et al N Engl J Med 2002;347:1326

Mortality Short-term: 5/303 deaths (1.7%) –2 in patients with severe pulmonary disease –1 pulmonary embolus (line-related DVT) –1 sudden AV block day 4 –1 sudden out-of hospital (?AV block) Long-term: 1 further death (pancreatic carcinoma)

Heart-Block Overall rate is ~ 20% requiring PPM Ranges from 0-40% Incidence appears to be reducing (contrast echo) 10% of surgical patients require PPM Beneficial effects of procedure similar in paced/not paced patients* *Shamin et al N Engl J Med 2002;347:1326

Arrhythmias Early VF in 1.6% No late arrhythmias reported

Late Ventricular Dilatation Information from 134 patients (4 reports) 4.2mm Pre 4.7mm Post Shamin et al N Engl J Med 2002;347:1326

Comparison with Surgery No randomised studies Two recent non-randomised comparisons –St George’s Hospital –Cleveland Clinic Patients well matched but septal ablation patients older and more co-morbidity

Cleveland ClinicSt. George’s Qin et al JACC 2001;38:1994 Firoozi et al Eur Heart J 2002;23:1617

Conclusions Still limited data Not profoundly aggressive Results similar to surgery Mortality and morbidity acceptable and similar to surgery Should be performed as part of a HCM service by experienced operators Patient selection of paramount importance