CARDIAC RESYNCHRONIZATION

THERAPY

Jeffrey J. Shultz, MD

Cardiac Electrophysiology

Park Nicollet Heart and Vascular Center

CASE: DK – 69 Y/O MALE

2006 - Aortic valve replacement and CABG. (No h/o MI)

LVEF remained approximately 45%

LBBB (ECG to be shown)

NYHA Class I

Carvedilol 25 mg BID, Lisinopril 20 mg daily, HCTZ, Coumadin, ASA, Amlodipine, Lipitor

2014 – Episodic dyspnea, LVEF down to 35%

Lasix and spironolactone added

Jan 2015 - Progressive DOE, NYHA Class III, Stress test = inferior ischemia and LVEF=20%

Feb 2015 – Cor Angio = non-occlusive CAD. Rx = Med Mgmt.

June 2015 – Remains NYHA Class III, LVEF=30%, Referred for Bi-V ICD

DK – 69 Y/O MALE

CONGESTIVE HEART FAILURE - MAGNITUDE OF THE PROBLEM

Estimated 5.1 million in US / 23 million worldwide (2006)

Exact numbers difficult due to varying inclusion criteria

Steep rise in incidence with age

3-4-fold increase in hospitalizations from 1971-1999

Increase in Mortality attributable to CHF from 5.8/1000 in 1970 to 16.4/1000 in 1993

$32 billion spent on treatment of CHF in US / year

DEATHS DUE TO CORONARY HEART DISEASE

NHLBI 2012

HOSPITALIZATIONS DUE TO CHF

NHLBI 2012

AGE-RELATED CHF

INCIDENCE(#/1000)

le

Male

Female

Bleumink, et.al. EHJ 2004

1. Framingham Heart Study (1948 – 1988) in Atlas of Heart Diseases.2. American Heart Association. Heart Disease and Stroke Statistics—2003 Update.

SYSTOLIC VERSUS DIASTOLIC CHF

Systolic – HF-REF

Impaired contractility / ejection

LVEF <50%

Approximately 2/3 of CHF prevalence

Common conditions - Ischemic CM, DCM

Multiple approaches to therapy

Diastolic – HF-PEF

Impaired LV relaxation / filling

LVEF = >50%

Approximately 1/3 CHF prevalence

Common conditions – HTN, elderly without HF-PEF, HCM, constrictive/ restrictive CM

Limited therapeutic options

HF-PEF VS HF-REF MORTALITY

Brouwers et.al, EHJ 2013

1. The Criteria Committee of the New York Heart Association. Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels. 9th ed. Boston, Mass: Little, Brown & Co; 1994:253-256

WEAPONS AGAINST SYSTOLIC CHF

Prevention – Education and management of CAD risk factors

Aggressive treatment of UA/STEMI/Non-STEMI

Medical therapy – ACE-I’s/ARB’s, ß-blockers, aldosterone antagonists, diuretics

Dietary / Fluid restrictions

Aggressive outpatient monitoring programs

Cardiac Resynchronization Therapy (CRT)

WHAT IS DYSSYNCHONY?

3 types of dyssynchrony

AV – Delay between atrial and ventricular contraction (AV block)

Interventricular – Delay between right and left ventricular activation (LBBB)

Intraventricular - normal ventricular activation sequence is disrupted, resulting in discoordinated contraction of the LV segments

CRT can help with all three

LEFT BUNDLE BRANCH BLOCK

Click icon to add picture

- Currently best measure of left ventricular dyssynchrony

- QRS duration > 120; preferably > 150 for CRT

HOW DO WE MEASURE DYSSYNCHRONY?

CRT DEVICES

CRT-D – Implantable Defibrillator capable of Bi-Ventricular Pacing (Most common)

CDT-P – Pacemaker capable of Bi-Ventricular Pacing (Has no ability to treat ventricular tachyarrhythmias)

CORONARY VENOUS ANATOMY

PRESSURE PRODUCTS® CSG® WORLEY SHEATH

CORONARY VENOUS ANATOMY

LV LEAD PLACEMENT

Dong et.al; Europace 2012

CRT INDICATIONS - 2012

Class 1 -  LVEF less than or equal to 35%, sinus rhythm, LBBB with a QRS duration greater than or equal to 150 ms, and NYHA class II, III, or ambulatory IV symptoms on GDMT.

Class 2a – LVEF less than or equal to 35%, sinus rhythm, LBBB with a QRS duration

120 to 149 ms, and NYHA class II, III, or ambulatory IV symptoms on GDMT.

LVEF less than or equal to 35%, sinus rhythm, a non-LBBB pattern with a QRS duration greater than or equal to 150 ms, and NYHA class III/ambulatory class IV symptoms on GDMT.

Atrial fibrillation and LVEF less than or equal to 35% on GDMT if a) the patient requires ventricular pacing or otherwise meets CRT criteria and b) AV nodal ablation or pharmacologic rate control will allow near 100% ventricular pacing with CRT

Patients on GDMT who have LVEF less than or equal to 35% and are undergoing new or replacement device placement with anticipated requirement for significant (>40%) ventricular pacing.

CRT INDICATIONS - 2012

Class 2b LVEF less than or equal to 30%, ischemic etiology of heart failure, sinus

rhythm, LBBB with a QRS duration of greater than or equal to 150 ms, and NYHA class I symptoms on GDMT

LVEF less than or equal to 35%, sinus rhythm, a non-LBBB pattern with QRS duration 120 to 149 ms, and NYHA class III/ambulatory class IV on GDMT

LVEF less than or equal to 35%, sinus rhythm, a non-LBBB pattern with a QRS duration greater than or equal to 150 ms, and NYHA class II symptoms on GDMT

Class 3 NYHA class I or II symptoms and non-LBBB pattern with QRS duration less

than 150 ms

Comorbidities and/or frailty limit survival with good functional capacity to less than 1 year.

REVERSE AND RAFT (2012)

REVERSE (REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction) and RAFT (Resynchronization/Defibrillation in Ambulatory Heart Failure) trials showed that Cardiac Resynchronization Therapy (CRT-D) reduced Heart Failure (HF) Hospitalization or All-Cause Death.

Looked at patients with;

NYHA Class IILeft Bundle Branch BlockLeft Ventricular Ejection Fraction ≤ 30%

QRS duration ≥ 130 ms

REVERSE AND RAFT - RESULTS

• REVERSE: Reduction of Worsened Clinical Composite Responsefrom 18% with CRT OFF versus 5% with CRT ON (p = 0.004) (Figure 1)

• REVERSE: 73% reduction in Time to First HF Hospitalization or All-Cause Death with CRT (p = 0.004) (Figure 2)

• RAFT: 42% reduction in Time to First HF Hospitalization or All-Cause Death with CRT-D (p < 0.0001)

REVERSE - RESULTS

EXPANDED CRT INDICATIONS WITH REVERSE AND RAFT

31

NYHA III/IV** NYHA II

QRS Duration Prolonged LBBB***, QRS ≥ 130 ms

LVEF ≤ 35% ≤ 30%

Optimal Medical Therapy Yes Yes

Approved Device(s) CRT-P, CRT-D CRT-D only

BLOCK HF TRIAL 2013

Objective: To determine if biventricular pacing with CRT is superior to right ventricular only pacing in patients with;

Class I or IIa pacing indication

NYHA class I, II, or III

LVEF </=50%

At least one of the following; 2nd or 3rd degree AV block

1st degree AV block with pacemaker syndrome

Documented Wenchebach block or PR interval >300 msec with pacing at 100 BPM

BLOCK HF - RESULTS

UPDATED RECOMMENDATIONS - APRIL 2014

AV block (prolonged 1st degree, 2nd or 3rd degree)

NYHA Class I, II, III heart failure LVEF ≤ 50% Optimal medical therapy (OMT) 

DK – 68 Y/O MALE

Under went implant of CRT-D on 6/17/15

ECG to be shown

Saw PMD on 7/21/15 – Feel great! No dyspnea or DOE.

Seen in Cardiology 9/2/15 – NYHA Class I-II

Echo – LVEF = 30% but LV chamber size noted to be smaller

DK – 69 Y/O MALE

DK – 68 Y/O MALE – POST CRT-D

CRT RESPONDERS

Approximately 70% response rate

30-40% will have objective improvement in LVEF

Characteristics of “responders” LBBB with QRS duration > 150 msec

QRS to LV pacing site > 110 msec

100% LV pacing

Common causes for being a “non-responder” Reduced LV pacing – lead dislodgement, atrial fibrillation, PVC’s

Poor LV lead position – anatomy, lead dislodgement

Programming issues – suboptimal AV delay or V-V timing

POTENTIAL IMPLANT COMPLICATIONS

Bleeding / hematoma / bruising

Infection

Cardiac perforation

Pneumothorax

Lead dislodgement

Diaphragm / Phrenic Nerve stimulation

Venous thrombosis

Vascular injury

Brachial plexus injury

Renal failure

Arrhythmia induction

CVA / MI / Death

PHRENIC NERVE STIMULATION

POST-OP CARE

Pain relief

Monitor typical post-op vital signs

Monitor wound – intact, no bleeding, limited swelling at site or arm

Monitor for pneumothorax / pericardial effusion / tampanade – sudden chest pain, dyspnea, hypotension, neck vein distention

Watch for loss of capture / change in pacing complex / over- and undersensing

Monitor for Diaphragm pacing

CONCLUSIONS

CHF remains a major clinical problem and is responsible for significant CV mortality and repeat hospitalizations

CRT has proven to be a significant adjunct to CHF medical therapy resulting in improved in survival and decreased hospitalizations

CRT can be performed with high rate of success and low rate of complications

Approx 70% will respond to CRT and LVEF will improve in approx 30-40%.

Looking for better ways to identify dyssynchrony and target dyssynchrony

LV lead positioning limited by anatomy, scar, diaphragm pacing