Septal ablation in Hypertrophic Cardiomyopathy

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

2. 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

3. 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

4. Myotomy-myectomy

5. 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

6. 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

7. 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

9. Septal Ablation - Published Reports • Knight et al Circulation 1997;95:2075 18 patients • Faber et al Circulation 1998;98:2415 91 patients • Lakkis et al Circulation1998;98:1750 33 patients • Gietzen et al Eur Heart J 1999;20:1342 50 patients • Kim et al Am J Cardiol 1999;83:1220 20 patients • Qin et al J Am Coll Cardiol 2001;38:1994 25 patients • Total 237 patients Longer term (7-36 month follow-up) • Gietzen et al Eur Heart J 1999;20:1342 37 patients • Faber et al Heart 2000;83:326 25 patients • Firoozi et al Eur Heart J 2002;23:1617 20 patients • Shamin et al NEJM 2002 ;347:1326 64 patients • Total 146 patients

10. Pre Post

11. 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

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

13. Effect on exercise • 3 reports assessed peak O2 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

14. 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)

15. 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

16. Arrhythmias • Early VF in 1.6% • No late arrhythmias reported

17. 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

18. 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

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

20. 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