1. Cardiac Resynchronization Therapy
Jeffrey J. Shultz, MD
Cardiac Electrophysiology
Park Nicollet Heart and Vascular Center

2. Case: DK – 69 y/o male
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 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

3. DK – 69 y/o male

4. 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
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

5. DeatHs due to coronary heart disease
NHLBI 2012

6. Hospitalizations due to CHF
NHLBI 2012

7. Age-related CHF Incidence (#/1000)le
Male
Age-related CHF Incidence (#/1000)
Female
Bleumink, et.al. EHJ 2004

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

9. Systolic versus Diastolic CHF
Systolic – HF-REF
Diastolic – HF-PEF
Impaired contractility / ejection
LVEF <50%
Approximately 2/3 of CHF prevalence
Common conditions - Ischemic CM, DCM
Multiple approaches to therapy
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

10. HF-pef vs hf-ref mortality
Brouwers et.al, EHJ 2013

11. 1. The Criteria Committee of the New York Heart Association
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:

12. 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)

13. 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

14. Left Bundle Branch Block
HOW DO WE MEASURE DYSSYNCHRONY?
Left Bundle Branch Block
- Currently best measure of left ventricular dyssynchrony
- QRS duration > 120; preferably > 150 for CRT

15. 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)

19. Coronary venous anatomy

20. Pressure Products® CSG® Worley Sheath

23. Coronary venous anatomy

24. LV lead placement
Dong et.al; Europace 2012

26. CRT Indications
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.

27. CRT Indications - 2012 Class 2b Class 3
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.

28. 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 II Left Bundle Branch Block Left Ventricular Ejection Fraction ≤ 30%
QRS duration ≥ 130 ms

29. REVerse and raft - results
• REVERSE: Reduction of Worsened Clinical Composite Response from 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 < )

30. Reverse - results

31. Expanded CRT indications with reverse and raft
NYHA III/IV**
NYHA II
QRS Duration
Prolonged
LBBB***, QRS ≥ 130 ms
LVEF
≤ 35%
≤ 30%
Optimal Medical Therapy
Yes
Approved Device(s)
CRT-P, CRT-D
CRT-D only
In this slide, the one column shows the FDA-approved labeling that Medtronic (and other manufacturers) received for NYHA Functional Class III and Ambulatory Class IV patients. In comparison, the FDA-approved labeling for Medtronic CRT-D devices in the NYHA Class II patients requires a left bundle branch block, a QRS duration of greater than or equal to 130 ms, an ejection fraction of less than or equal to 30%, and optimal medical therapy. Note that the labeling is only for CRT-D and not CRT-P.

32. 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

33. Block hf - results

34. 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) 

35. 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

36. DK – 69 y/o male

37. DK – 68 y/o male – post CRT-D

38. 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

39. 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

40. Phrenic Nerve Stimulation

42. 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

43. 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 %.
Looking for better ways to identify dyssynchrony and target dyssynchrony
LV lead positioning limited by anatomy, scar, diaphragm pacing