Resynchronization Therapy Nitish Badhwar, MD, FACC, FHRS Associate - - PDF document

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Update on Cardiac Resynchronization Therapy

Nitish Badhwar, MD, FACC, FHRS Associate Chief, Cardiac Electrophysiology Director, Cardiac Electrophysiology Training Program Stone-Chamberlain Endowed Chair in Cardiology University of California, San Francisco Innovative Procedures, Devices, and State of the Art Care for Arrhythmias, Heart Failure and Structural Heart Disease October 8, 2015

Disclosures

Honoraria - St. Jude, Biosense, Senterheart Fellowship Support – Medtronic, St. Jude, Boston Scientific, Biotronik,

• Update on indications
• CRT optimization
• Role of imaging

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• Annual incidence

550,000

• Incidence 10/1000 population > 65 years
• Prevalence

4.7 million

• Acute HF hospitalization

3 million

• Annual mortality

250,000

Burden of Heart Failure LBBB and Heart Failure

Narrow QRS EF 47% LBBB EF 30%

Deleterious Effects of Ventricular Dyssynchrony

Reduced

diastolic filling time 1 + Weakened contractility 2 + Protracted mitral regurgitation 2 + Post systolic regional contraction 3 = Diminished stroke volume

• 1. Grines CL, et al Circulation 1989;79:845-853
• 2. Xiao HB, et al Br Heart J 1991;66:443-447
• 3. Søgaard P, et al. J Am Coll Cardiol 2002;40:723–730

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Cardiac Resynchronization Therapy (CRT)

Baseline qrs 160 ms Biv pacing qrs 120 ms

Effects on Remodeling

Post CRT Pre CRT

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Effects on Remodeling

Post CRT Pre CRT

Benefits of CRT in Advanced Heart Failure

• Clinical outcomes

– Exercise capacity – Quality of life – Heart failure hospitalization

• CRT leads to reverse remodeling
• Mortality benefit (COMPANION,

CARE-HF)

• Sinus rhythm
• Advanced heart failure (NYHA Class III or IV)
• QRS complex duration > 120 ms (Electrical

dyssynchrony assumed to be a correlate of mechanical dyssynchrony)

• Left Ventricle Ejection Fraction (LVEF) < 35%
• Ischemic or non-ischemic cardiomyopathy
• Optimal drug therapy for heart failure

Strickberger SA et al. Circulation. 2005;111:2146-2150

Indications for CRT

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QRS Duration and Morphology

• QRS morphology

– LBBB – RBBB – Non LBBB

• QRS duration

– > 150 ms – 120-150 ms – < 120 ms

RV Pacing PAVE: BiV vs RV pacing in pts with AF and AVN ablation

Doshi et al. JCE 2005;Vol 16:1160-65.

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Block HF: CRT in pts with AV block and mild LV dysfunction (EF ≤50%)

Curtis AB et al. NEJM 2013;368(17):1585-93

• e

g n g t r g h e d r e

Event-free Rate (%) 100 80 90 70 60 40 30 10 50 20 12 24 36 48 60 72 Months

• No. at Risk

Biventricular pacing Right ventricular pacing 349 342 161 126 87 59 62 39 38 28 17 18 3 10 Biventricular pacing Right ventricular pacing

• Sinus rhythm class I indication
• RV pacing induced class IIa indication
• Atrial fibrillation class IIa indication

Indications for CRT

REVERSE REMODELING WITH CRT (BIV) in NYHA Class III-IV

EF=0.20 EF=0.36 NYHA III-IV NYHA II-III ECG

QRS = 0.15s QRS = 0.14s LV

LV MI MI CRT

DYSFUNCTIONAL REMODELING

EF=0.30 EF=0.20 NYHA I-II NYHA III-IV ECG Early Late

QRS = 0.12s QRS = 0.16s LV

LV MI MI

Remodeling Can CRT prevent this?

Can CRT benefit patients with early heart failure

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• MADIT CRT, RAFT, MIRACLE-ICD II, REVERSE
• Improved mortality and hospitalization
• Lead to LV reverse remodeling

CRT and mild HF (NYHA II)

Santangeli P et al. JICE. 2011;32(2):125-135.

MADIT-CRT: Outcome by LBBB & Non-LBBB

HR=0.45 P=0.001 HR=1.25 P=0.25

QRS Morphology and CRT

CRT-D Better ICD-only Better

CRT-D:ICD Hazard Ratios for Prespecified Subgroups

Significant Sex-Rx Interaction Significant QRS-Rx Interaction

QRS duration and CRT

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2012 CRT Guideline Update

ACCF/AHA/HRS Focused Update. JACC. 2012;60 (14):1297-1313

2012 CRT Guideline Update

ACCF/AHA/HRS Focused Update. JACC. 2012;60 (14):1297-1313 Class III: No Benefit

• 1. CRT is not recommended for patients with NYHA class I or II symptoms and non-

LBBB pattern with QRS duration less than 150 ms (20,21,30). (Level of Evidence: B) New recommendation

• 2. CRT is not indicated for patients whose comorbidities and/or frailty limit survival with

good functional capacity to less than 1 year (19). (Level of Evidence: C) Modified recommendation (wording changed to include cardiac as well as noncardiac comorbidities).

+

NARROW OW Q QRS

Dyssynchrony Echo

To T Test t the H Hyp ypothesis t that C CRT C Can H Help Heart F Failure P Patients W With Narrow Q QRS if if they h y have a a p positive Dys Dyssyn ynch chrony Ech y Echo CRT in narrow QRS patients: Negative study

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• Update on indications
• CRT optimization
• Role of imaging
• 30% patients with HF NYHA III-IV qualify for CRT

based on EKG criteria

• 30-40% patients with HF NYHA III-IV and narrow

QRS who do not qualify for EKG criteria for CRT have evidence of mechanical dyssynchrony by imaging

• 30% patients do not respond to CRT
• 10-29% patients show super or hyper response

with EF > 50% and NYHA I

Cardiac Resynchronization Therapy

• RBBB
• Ischemic cardiomyopathy
• NYHA IV
• Advanced age
• Discordant LV lead and myocardial scar

Poor Responders to CRT

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“Non responders”: Medical causes

• Suboptimal HF therapy
• Mitral regurgitation +/- ischemia
• Comorbidities (COPD, anemia,

arthritis, amiodarone)

• End stage heart disease

– Restricitve pattern on echo – RV dysfunction § Lower % BiV pacing due to – AT/AFib/Aflutter with rapid ventricular rates – Higher threshold with loss of LV capture – Lead dislodgement – Phrenic stimulation – Anodal stimulation § Inadequate rate response § Suboptimal PV or AV delay § Suboptimal V-V timing § LV lead position § LV dyssynchrony

“Non responders”: Device causes ECG to Assess BiV Pacing

• BIV capture produces a rightward axis

(negative or initial negative in leads I, AVL and positive in aVR) and R>S in lead V1 .

• R–S ratio ≥ 1 in lead V1 , q in lead I, R-S

ratio of ≤ 1 in lead I suggest BIV pacing.

• 12 lead ecg in basal post lat vein does

not give complete negative complex in 1, avL ..it looks like LBBB with narrower QRS.

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Maximizing Biventricular Pacing

• Maximizing beta-blocker therapy
• Negative AV/PV hysteresis ensures constant

ventricular pacing by shortening the AV/PV delay if intrinsically conducted R waves are sensed.

• Biv trigger pacing; adaptive CRT
• AV Junction ablation in patients with Atrial fibrillation

and rapid ventricular conduction (< 85% biv pacing) Options for patients at risk of rapid intrinsic conduction?

AV and VV optimization

• Echo based (Mitral inflow and Aortic VTI)
• EKG based
• EGM based (through the device)

AV and V-V Optimization

• Statistically speaking: the average
• ptimal AV delays were between

170-190 ms, and the average optimal V-V delays were between 20-30 ms.

• In almost all studies, approximately

60% of all patients were paced LV first.

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• Update on indications
• CRT optimization
• Role of imaging

Mechanical Dyssynchrony

• Electrical dyssynchrony (wide QRS) = Mechanical

dyssynchrony

• Some patients with wide QRS may not have

mechanical dyssynchrony

• Narrow QRS patients with heart failure may have

mechanical dyssynchrony

A B

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Equilibrium Radionuclide Angiogram (ERNA)

B A B Dyssynchrony - Dyssynchrony +

The Solution

§ Need imaging modality that reliably measures mechanical dyssynchrony § Echo § MRI / CT § ERNA (Equilibrium radionuclide angiogram)

Role of ERNA to select patients for CRT

A combined preoperative value of S ≤ 0.88 and E > 0.69 predicted clinical improvement in 86% of the patients after CRT. The remainder showed clinical improvement only in 56% of the patients.

Badhwar N et al. J Nucl Med. 2008;49(1):274P.

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Levophase for Coronary Sinus Anatomy

Anterior Anterolateral Lateral Posterolateral Posterior

Coronary Sinus Anatomy

Singh J P et al. Circulation 2011;123:1159-1166

LV lead position and Clinical Outcomes

• No difference among Anterior, Posterior and Lateral lead positions
• Apical lead positions associated with a significantly worse clinical
• utcome

Anterior, posterior and lateral position Apical versus Non-apical position

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LV Lead Concordance with Latest Activated Segment by ERNA Predicts Improvement after CRT CRT Non-Response:Postlateral Aneurysm by Echo

I II III aVR aVL aVF V1 V2 V3 V4 V5 V6 Referred by: 41898 BADHWAR Confirmed By: ELLEN KILLEBREW

LV pacing in scar region

• Long delay from stimulus to LV capture
• No benefit derived from BiV pacing, can even

lead to worsening of symptoms due to RV pacing

• Rarely can lead to ventricular tachycardia in

patients with ischemic heart disease (inferoposterior MI)

• Role of viability assessment (PET scan, MRI)

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Role of Imaging in CRT

• Dyssynchrony evaluation

– Predict response in patients with QRS >150 ms – Select patients with QRS 120-150 ms and < 120 ms (pending results of ECHO CRT) – Select patient with non LBBB and RBBB

• Guiding LV lead placement
• Assessment of coronary sinus anatomy
• Assessment of scar and viability
• Optimization of CRT with echo

Virtual CRT

• Baseline ECG
• Imaging to assess mechanical dyssynchrony,

scar and area of latest LV contraction

• Body surface map to assess latest electrical

activation

• CT / MRI to assess coronary sinus anatomy
• Heart model to predict response to CRT
• Plan coronary sinus vs endocardial LV vs

surgical epicardial LV lead placement based on imaging

Thank you