Modern devices such as implantable defibrillators (ICDs) and cardiac resynchronization therapy (CRT) are playing an expanding role in treating heart failure. CRT aims to improve synchronization of ventricular contractions in patients with left bundle branch block and a widened QRS complex. It has been shown to improve symptoms, exercise capacity, and reduce hospitalizations and mortality in moderate to severe heart failure patients. ICDs provide protection against sudden cardiac death from arrhythmias in patients with reduced left ventricular ejection fraction. Guidelines recommend considering CRT for appropriate candidates with LVEF <35% and QRS >120ms and considering ICDs for those with LVEF <35% who are not in NYHA

1. Modern Solutions to Heart Failure – role of devices Dr. P. Clarkson Consultant Cardiologist Raigmore Hospital Inverness

2. Heart Failure - Demography UK prevalence of 1.5% Highland Population 3500 patients Natural history - 5 year survival (male-Framingham) 25% Modern drugs – 20% mortality at 2.5 yrs 5% of medical admissions Prevalence increasing with ageing population and greater survival of IHD patients

3. Poor Quality of Life for HF patients Hobbs FDR, et al. Eur Heart J 2002;23:1867-1876

4. Aetiology of heart failure Valves? Rhythm? Pump (LV) function? Also secondary causes e.g cor pulmonale with right heart failure

5. Dilated Cardiomyopathy

6. Mitral Stenosis

7. NSF - Aim of treating cardiac failure Improve symptoms / slow deterioration Reduce mortality Reduce cardiac events / admissions to hospital Avoid adverse treatment effects Improve end of life experience for both patients and carers

8. Drugs Diuretics – aim for lowest dose to control symptoms ACE Inhibitors – start before b-blockers, start at low dose, titrate every few weeks, checking biochem at each increment Spironolactone – if symptoms persist can add this in, but specialist advice recommended Digoxin – if atrial fibrillation or severe heart failure despite ACE, b-blockers and diuretics Aspirin – if combination of heart failure and atherosclerotic arterial disease Statins if known atherosclerotic vascular disease

9. Non medical treatment of heart failure Transplantation Biventricular pacing (resynchronisation) Implantable defibrillators (ICD)

10. Cardiac Transplantation Final approach for advanced heart failure In UK < 300 donor hearts per year and decreasing Will never help more than a small percentage of heart failure patients Xenotransplantation from GM pigs poses complex ethical dilemmas / clinical problems

11. Cardiac Resynchronisation (CRT) – electrical timing Disordered electrical timing frequent in damaged ventricles esp in LBBB Normal ventricular activation is rapid with minimal time delay throughout ventricular wall Intra LV delay causes dys-synchronous contraction Mechanically inefficient. Also redistributes mechanical load in LV reducing wall thickness at site of early activation Delayed sequential activation of papillary muscles can aggravate MR

12. Prevalence of Ventricular Dyssynchrony in Heart Failure 1. Masoudi, et al. JACC 2003;41:217-23 2. Aaronson, et al. Circ 1997;95:2660-7

13. Prognosis with Ventricular Dyssynchrony Baldasseroni S, et al. Eur Heart J 2002;23:1692-98 N=5,517

14. How to detect dys-synchrony ECG – broad QRS complex ECHO – often very obvious on ‘eyeball’ Other indices e.g. speckle tracking

15. Ventricular Resynchronisation - CRT Recently developed pacing strategy for severe heart failure For patients with asynchronous LV contraction Correction of intra LV conduction delay Pacing leads in RA/RV/Cardiac veins

16. Achieving Cardiac Resynchronization Goal: Atrial synchronous biventricular pacing Transvenous approach for left ventricular lead via coronary sinus Doug Smith: Right Atrial Lead Right Ventricular Lead Left Ventricular Lead

17. CRT Procedure and Device Related Risks Venous anatomy highly variable 20% no vein in optimal site Phrenic nerve stimulation No stimulation in scar tissue Veins either too small or too large

18. CRT Improves Quality of Life & Functional Capacity in Moderate to Severe Heart Failure QoL Score (MLWHF) Avg. Change Data sources: MIRACLE: Circulation 2003;107:1985-90 MUSTIC SR: NEJM 2001;344:873-80 MIRACLE ICD: JAMA 2003;289:2685-94 Contak CD: J Am Coll Cardiol 2003;2003;42:1454-59  Control  CRT NYHA Class Proportion Changing 1 or more Classes Improve.  Not Reported

19. CRT Symptom benefit All RCT’s have shown alleviation of symptoms and increased exercise capacity On average NYHA decreased by 0.5-0.8 6 min walk distance increased by 20% VO2 max increased by 10-15% Lowers hospitalisation by 39-76% With current selection only 70% respond

20. Pre Device 1 Day post CRT 2 Months post CRT 1 Year post CRT

21. Mortality effects of CRT

22. Cardiac Resynchronisation- NICE guidance -2007 LVEF < 35% NYHA 3 – 4 recently experienced Sinus Rhythm QRS > 150ms or >120ms plus echo dys-synchrony Optimal Medical Therapy SIGN 2007 – very similar QRS>120ms

23. MADIT-CRT (III) N Engl J Med 2009;361

24. Methods – MADIT-CRT enrollment: N = 1820, 12/2004 – 04/2008 inclusion: ICMP NYHA I,II (N = 265, 734) NICMP NYHA II (N = 821) EF ≤ 30% (mean EF = 24 %) QRS ≥ 130 ms (65 % had QRS ≥ 150 ms, 70 % LBBB) stable CHF, optimal medication, SR at least 1 m before enrollment randomization CRT-D (3) : ICD (2) Moss et al., N Engl J Med 2009;361

26. Sub-analysis MADIT-CRT Moss et al., N Engl J Med 2009;361

27. 2010 European Guidelines All for LVEF <35% NYHA III-IV, QRS>120ms, SR, optimal med NYHA II, QRS>150ms, SR, optimal med NYHA III-IV, QRS>130ms, AF but slow enough to pace 95%, optimal meds Needs an anti bradycardia PPM with NYHA III-IV and QRS>120ms

28. Current challenges in CRT Patient selection – only 70% respond Lack of perfect screening/selection tool Limitations of anatomy Mechanistic research still required

29. TriVentricular CRT 2 CS and RV lead 2 RV and CS lead

30. 6 minute walk p = 0.008

31. Responders BiV: TriV: 70% 81%

32. How are we doing with CRT?

33. Implantable Defibrillators in heart failure

35. Sudden Cardiac Arrest is one of the Leading Causes of Death in the U.S. In UK 50,000 – 70,000 sudden cardiac arrests per annum 0 5 0 , 0 0 0 1 0 0 , 0 0 0 1 5 0 , 0 0 0 2 0 0 , 0 0 0 2 5 0 , 0 0 0 3 0 0 , 0 0 0 A I D S B r e a s t C a n c e r L u n g C a n c e r S t r o k e S C A

36. Underlying Arrhythmia of Sudden Cardiac Arrest Survival rate for OOHCA is <5% Primary VF 8% Torsades de Pointes 13% Bradycardia 17% VT 62%

37. Rhythm Strip During Episode of Sudden Death Josephson, ME 6:02 AM 6:05 AM 6:07 AM 6:11 AM

38. Sudden Cardiac Death Incidence and Total Events Overall Incidence in Adult Population Source: Myerburg RJ. Circulation. 1992;85(suppl I):I-2 – I-10. High Coronary Risk Sub-Group Any Prior Coronary Event EF < 30% Heart Failure Out-of-Hospital Cardiac Arrest Survivors 30 20 10 5 2 1 0 (%) Incidence (%/Year) 300 200 100 0 (x 1000) Total Events (#/Year)

39. Severity of Heart Failure . Modes of Death NYHA II 12% 64% 24% CHF Other Sudden Death Deaths = 103 NYHA IV 56% 11% 33% CHF Other Sudden Death Deaths = 27 NYHA III 26% 15% 59% CHF Other Sudden Death Deaths = 232

40. Therapies Provided by Today’s Dual-Chamber ICDs Atrium & Ventricle Ventricle Antitachycardia pacing Cardioversion Defibrillation Bradycardia sensing Bradycardia pacing

41. Defibrillators –Primary Prevention Guidance post MI NICE guidance - 2006 Post MI > 4 weeks NYHA I-III and either LVEF < 30% and QRS > 120ms or LVEF < 35% and non sustained VT on Holter monitoring and inducible VT on EP Testing SIGN guidance – 2007 and ESC 2010 1/12 post MI NYHA I-III and LVEF <35%

42. Number of ICD implants NICE – 5.8% of post MI should get an ICD ESC - 37% of post MI should get an ICD Approx cost £10,000

43. Non-ischaemic cardiomyopathy - guidance NICE/SIGN – None! ESC – LVEF<35% NYHA II-III good functional status

44. How are we doing with ICD’s

45. Biventricular ICD’s Essentially a combination of ICD and CRT devices Current indication - those who fulfil criteria for both ICD and CRT

46. Heart Failure and Devices – Summary Common Condition Complex Therapeutics Expanding and changing treatment strategies Expanding role for devices ICD’s – consider if LVEF < 35% and not NYHA IV CRT – consider if LVEF < 35%, QRS > 120ms and has symptoms