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
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