8/8/2011. CARDIAC RESYCHRONIZATION THERAPY for Heart Failure. Case Presentation. Case Presentation

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1 CARDIAC RESYCHRONIZATION THERAPY for Heart Failure James Taylor, DO, FACOS Cardiothoracic and Vascular surgery San Angelo Community Medical Center San Angelo, TX Case Presentation 64 year old female with history of Severe dilated cardiomyopathy Depressed left ventricular function with EF < 15% Chronic congestive heart failure on continuous home O2 Second degree heart block Coronary artery disease, post CABG Moderate to severe mitral valve regurgitation Poorly controlled diabetes mellitus Chronic obstructive pulmonary disease Sleep apnea Obesity, rheumatoid arthritis, fibromyalgia depression Case Presentation Problems: Pt deemed too high risk for mitral valve repair Maximum medical therapy Pt on continuous home oxygen Continuous multiple hospital admissions many for a month Life limiting illness Any hope?? 1

2 Case Presentation Consider Cardiac Resynchronization Therapy Defibrillator (CRT-D) Components: Pacemaker Implantable Cardioverter Defibrillator (ICD) Biventricular lead placement for ventricular resynchronization Permanent Pacemaker Purpose treat slow heart rates (bradycardia) allow cardiac medications to treat cardiac arrhythmias synchronize atrial-ventricular conductivity (heart block) atrial fibrillation therapy rate response to activity Pacemaker Syndrome Loss of AV Synchrony Shortness of breath Fatigue Syncope Vertigo CHF, pulmonary edema Cannon A-waves Dizziness Palpitations Pulsations in the neck Chest pain Near syncope Confusion 2

3 Pacemaker Syndrome Hemodynamic Penalties From Loss of AV Synchrony Loss of atrial contribution Decrease in stroke volume Decrease in cardiac output Decrease in cerebral perfusion Decrease in coronary blood flow Treatment of Pacemaker Syndrome Dual-chamber pacing Normal atrial sensing and capture Appropriate AV delay Permanent Pacemaker Generator Leads 3

4 History of Pacemaker Batteries 1958 Cadmium Nickel Oxide batteries rechargeable Zinc Mercuric Oxide batteries (2 years longevity) 1970 Nuclear batteries (20 year longevity) 1972 Lithium-Iodine technology has been the primary source for pacemakers Pacemaker Leads Unipolar System In a unipolar system, current flows from the lead tip to the pulse generator can Bipolar System In a bipolar system, current flows from the lead tip to the ring electrode Active vs. Passive 4

5 Active vs. Passive Steriod Eluting leads Decrease inflammatory response to lead placement Decrease formation of fibrosis/scar tissue Increase function of lead by lowering resistance Increase battery life NASPE/BPEG Code Position: I II III IV V Category: Chamber(s) Paced Chamber(s) Sensed Response to Sensing Rate Modulation Multisite Pacing Letters Used: O None O None O None O None O None A Atrium A Atrium T Triggered A Atrium V Ventricle V Ventricle I Inhibited R Rate Modulation V Ventricle D Dual A+V D Dual A+V D Dual T+I D Dual A+V 5

6 Permanent Pacemaker Rate modulation Prolonged AV Conduction Sinus node AV node Sub-optimal contribution of atrial systole Limited filling period Diastolic mitral regurgitation 17 Prolonged AV Conduction Shorten AV Delay Improves AV Synchrony Sinus node Improves blood transfer from atrium to ventricle Reduces diastolic mitral regurgitation Lengthens diastolic filling period 18 6

7 AV Synchrony Cardiac Output = Stroke Volume Heart Rate Facilitates venous return Increases LVEDP Maintains appropriate opening and closing of AV valves Hemodynamic advantage of AV sequential pacing When compared to ventricular pacing alone: 10 53%* increase in resting cardiac output Implantable Cardioveter Defibrillator System (ICD) Purpose treat life threatening fast ventricular arrhythmias Sudden cardiac arrest (SCA) accounts for half of all cardiac-related deaths 1 7

8 Every day, more than 650 people are struck by sudden cardiac arrest. 2 That's a life every 2 minutes. 2 That s greater than the number of deaths each year from breast cancer, lung cancer, stroke, and AIDS combined. 3 95% of them die before reaching a hospital. 4 However: 90% or more of lethal ventricular arrhythmias have been shown to be able to be effectively terminated by ICDs. 4 New England Journal of Medicine published MADIT II 6 results in the article: PROPHYLACTIC IMPLANTATION OF A DEFIBRILLATOR IN PATIENTS WITH MYOCARDIAL INFARCTION AND REDUCED EJECTION FRACTION Proved for first time that primary prevention patients (heart attack survivors with EF 30%) benefit from ICD therapy vs. conventional medical therapy First trial to show the lifesaving benefits of ICDs without requiring invasive EP testing or surviving SCA Cardiac Resynchronization Therapy (CRT) for Heart Failure 8

9 Overview 2 Key Patient Issues Associated with Heart Failure Delayed Ventricular Activation Prolonged AV Conduction Clinical Findings Conduction disturbances Wall motion abnormalities Mitral regurgitation impacting ventricular filling Diminished contractility Equals diminished cardiac output! Diminished cardiac output may become irreversible Delayed Ventricular Activation An overlooked source of ventricular dysfunction Generally occurs in left ventricle (LBBB) Conduction disorders associated with impaired left ventricle dysfunction 9

10 Delayed Ventricular Activation Ventricular conduction delay Surface ECG Left bundle branch block Muscle fiber conduction to LV m/s Prolonged QRS Delayed Ventricular Activation Mechanical dyssychrony Delayed conduction Delayed contraction Interventricular delay Purkinje conduction m/s Inefficient pumping Muscle conduction m/s Delayed Ventricular Activation Assessment of mechanical dyssynchrony ECHO: Abnormal LV wall motion Normal DCM (no CRT) 10

11 Delayed Ventricular Activation Assessment of mechanical dyssynchrony MRI: Non-Uniform Myocardial Shortening Normal DCM longer septum base septum base relaxed shorter apex apex Delayed Ventricular Activation Ventricular Resynchronization the area of delayed electrical activation (pre-excitation) septum Interventricular delay Symmetric lateral & septal conduction & contraction More efficient pump 32 Delayed Ventricular Activation Mechanism I: Effects of CRT CRT Global Synchrony DCM CRT OFF DCM CRT 3 Mos 33 Courtesy of C. Stellbrink, MD 11

12 CRT Summary There are two common conduction issues in heart failure: Delayed ventricular activation Prolonged AV conduction The result is mechanical dyssynchrony CRT can restore synchrony by preexciting the site of latest ventricular activation CRT promotes AV synchrony using a shorter than intrinsic AV interval to achieve 100% biventricular pacing Improved synchrony increases ventricular filling reduces diastolic mitral regurgitation improves cardiac output Higgins SL, Hummel JD, Niazi IK, Giudici MC, Worley SJ, Saxon LA, Boehmer JP, Higginbotham MB, De Marco T, Foster E, Yong PG. Cardiac resynchronization therapy for the treatment of heart failure in patients with intraventricular conduction delay and malignant ventricular tachyarrhythmias. J Am Coll Cardiol Oct 15; 42 (8): QRS width is a RELATIVE predictor of CRT success Patients with wider QRS demonstrate greater short-term response to CRT 1,2,3 QRS width may be a predictor of chronic benefit 2,3 Patients with a narrow QRS (<120ms) may also possess significant dyssynchrony and benefit from CRT 4,5 1 Kass D et al. Circulation. 1999;99(12): Aurrichio A et al. [Abstracts #99, #103] Pacing Clin Electrophys. 2002;25(4 Pt 2): Aurrichio A et al. [Abstract #220] Pacing Clin Electrophys. 2003;26(4 Pt 2): Bleeker GB et al. J Am Coll Cardiol 2006;48: Yu CM et al. J Am Coll Cardiol 2006;48: CRT Variables Ventricular dyssynchrony QRS may not be a Reliable Predictor of Mechanical Synchrony in Heart Failure in this study Systolic Mechanical Dyssynchrony Standard Deviation of Time to Peak Systolic Contraction Patients with mechanical dyssynchrony HF patients HF patients ~50% ~70% N = 200 Controls Narrow QRS 120 ms Wide QRS 36 Yu, CM et.al. Heart. 2003; 89: Reprinted with permission of BMJ Publishing 12

13 CRT Variables Ventricular dyssynchrony Ventricular Dyssynchrony Summary QRS width is a fast method to identify electrical ventricular dyssynchrony The wider the QRS the greater the likelihood of mechanical dyssynchrony and CRT benefit Benefits of CRT Patient symptoms (NYHA Class) 1 Hemodynamics (dp/dt, pulse pressure) 2 Functional status (6 minute walk distance, VO2) 3 Quality of Life (Minnesota Living With Heart Failure) 4 Ventricular remodeling (Increased EF, Decreased LVEDD) 5 Hospitalizations 6 Survival 7,8 1 MIRACLE, CONTAK CD, COMPANION 2 PATH CHF 3 MIRACLE, CONTAK CD, COMPANION 4 MIRACLE, CONTAK CD, COMPANION 5 MIRACLE, CONTAK CD 6 MIRACLE, COMPANION 7 COMPANION 8 CARE HF CRT Benefits: patient symptoms European Study: Peak Oxygen Uptake Low Peak Oxygen Update Predicts Increased Mortality Survival Rate (%) Improved survival in patients with peak VO 2 > 14 ml/kg.min VO 2> 14 ml/kg/min N = VO 2 14 ml/kg/min N = Roul G, Moulichon ME, Bareiss P, et al. Exercise peak VO 2 determination in chronic heart failure: is it still of value? European Heart Journal. 1994;15:

14 CRT Benefits: patient symptoms CONTAK CD: Improvement in Peak VO 2 after 6 months of CRT CRT Benefits: patient symptoms CONTAK CD: Significance of Peak VO 2 Change Correlates with an important increase in the ability to perform daily life activities Daily Activities % Peak VO 2 = 1.8ml/kg/min +.06* Unrestricted Active 80 Independent 70 Mobile with assistance Homebound Bed to Chair Bedridden Oxygen Uptake (ml/kg/min) Jones N, Clinical Exercise Testing. Saunders. 41 *CONTAK CD Clinical Report, Boston Scientific 2001 CRT Benefits: functional status Study Results: Six Minute Walk Distance A Predictor of Mortality in Patients with Heart Failure N = 176 P< 0.02 Mortality (%) N = 241 N = 215 N = < > 450 Distance Walked (m) 42 Bittner V, Weiner DH, Yusuf S, et al. Prediction of mortality and morbidity with a 6-minute walk test in patients with left ventricular dysfunction. JAMA. 1993;270:

15 CRT Benefits: functional status CONTAK CD: Improvement in QOL Score after 6 months of CRT All Patients NYHA class III & IV 43 CONTAK CD Clinical Report, Boston Scientific 2001 CRT Benefits: left ventricle size Study Results: A Predictor of Mortality in Patients with Heart Failure Probability of Survival 100% 75% 50% 25% 0% Massive LV size was found to identify patients at risk of sudden death Moderate LV index < 4 cm/m 2 Massive LV index > 4 cm/m 2 n = 80 Months P= Lee T, et al. Impact of left ventricular cavity size on survival in advanced heart failure. Am J Cardiol. 1993;72: CRT Benefits: ventricular remodeling CONTAK CD: Improvement in LVID after 6 months of CRT All Patients NYHA class III & IV 45 CONTAK CD Clinical Report, Boston Scientific

16 CRT Benefits: ventricular remodeling CONTAK CD: Improvement in Ejection Fraction All Patients NYHA class III & IV 46 CONTAK CD Clinical Report, Boston Scientific 2001 CRT Benefits Hospitalization and Survival CARE-HF Study: Primary Endpoint All-cause mortality or unplanned hospitalization for major CV event 1.00 Event-free Survival HR 0.63 (95% CI 0.51 to 0.77) P <.0001 CRT Medical Therapy Days Number at risk CRT Medical Therapy Adapted from Cleland JG, Dauber JC, Erdmann E et al. for the Cardiac Resynchronization Heart Failure (CARE-HF) Study Investigators. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med 2005;352: CRT Benefits Hospitalization and Survival CARE-HF Study: Secondary Endpoint All-cause mortality 1.00 Event-free Survival HR 0.64 (95% CI 0.48 to 0.85) P =.0019 CRT Medical Therapy Days Number at risk CRT Medical Therapy Adapted from Cleland JG, Dauber JC, Erdmann E et al. for the Cardiac Resynchronization Heart Failure (CARE-HF) Study Investigators. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med 2005;352:

17 Coronary Sinus Coronary Sinus 17

18 Cardiac Resynchronization Therapy Defibrillator (CRT-D) Summary Corrects mechanical and electrical cardiac dysfunction by: Correcting A-V dissociation Resynchronizing ventricular dissociation Protection against dangerous cardiac arrhythmias Cardiac Resynchronization Therapy Defibrillator (CRT-D) Summary Indications Cardiac Resynchronization Therapy Defibrillators (CRT-D) are indicated for patients with heart failure who receive stable optimal pharmacologic therapy (OPT) for heart failure and who meet any one of the following classifications: Moderate to severe heart failure (NYHA class III IV) with EF < 35% and QRS duration >120 ms. Left bundle branch block (LBBB) with QRS > 130 ms, EF < 30%, and mild (NYHA class II) ischemic or nonischemic heart failure or asymptomatic (NYHA class I) ischemic heart failure. 18

19 Cardiac Resynchronization Therapy Defibrillator (CRT-D) Summary: Ventricular remodeling (decreased ventricular hypertrophy) Increased heart function (ejection fraction) Increased oxygen delivery Decreased hospital admissions Decrease in mortality Improved quality of life Questions???? 19