Cardiac resynchronization therapy indications

Cardiac resynchronization therapy Microchapters
Home
Overview
Indications
Landmark Trials
Contraindications
Pathophysiologic Basis for CRT
Treatment
Preoperative Evaluation
Procedure
Recovery
Outcomes and Prognosis
Complications
Cardiac resynchronization therapy indications On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Cardiac resynchronization therapy indications All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Cardiac resynchronization therapy indications
CDC on Cardiac resynchronization therapy indications
Cardiac resynchronization therapy indications in the news
Blogs on Cardiac resynchronization therapy indications
Directions to Hospitals Administering Cardiac resynchronization therapy
Risk calculators and risk factors for Cardiac resynchronization therapy indications

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief:: Bhaskar Purushottam, M.D. [2] Synonyms and Keywords: CRT

Overview

Cardiac resynchronization therapy (CRT) with or without an ICD is indicated in patients who have an LVEF less than or equal to 35%, a QRS duration greater than or equal to 0.12 seconds, and normal sinus rhythm, for the treatment of NYHA functional Class III or ambulatory Class IV heart failure symptoms in patients whose medical therapy has been optimized.

2012 American College of Cardiology Foundation/American Heart Association Task Force/HRS Focused Update of the 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities (DO NOT EDIT)

“

New Joint Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities Class I 1) CRT is indicated for patients who have 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. (Level of Evidence: A for NYHA class III/IV (16–19); Level of Evidence: B for NYHA class II) Class IIa 1) CRT can be useful for patients who have 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. (Level of Evidence: B) 2) CRT can be useful for patients who have 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. (Level of Evidence: A) 3) CRT can be useful in patients with 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. (Level of Evidence: B) 4) CRT can be useful for 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. (Level of Evidence: C) Class IIb 1) CRT may be considered for patients who have 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. (Level of Evidence: C) 2) CRT may be considered for patients who have 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. (Level of Evidence: B) 3) CRT may be considered for patients who have 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. (Level of Evidence: B) Class III 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) 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)

”

For ACC/AHA Level of evidence and classes click here.

ACC / AHA Guidelines - Recommendations for Cardiac Resynchronization Therapy in Patients with Severe Systolic Heart Failure (DO NOT EDIT)

“

Class I 1) For patients who have LVEF less than or equal to 35%, a QRS duration greater than or equal to 0.12 seconds, and sinus rhythm, CRT with or without an ICD is indicated for the treatment of NYHA functional Class III or ambulatory Class IV heart failure symptoms with optimal recommended medical therapy. (Level of Evidence: A) Class IIa 1) For patients who have LVEF less than or equal to 35%, a QRS duration greater than or equal to 0.12 seconds, and AF, CRT with or without an ICD is reasonable for the treatment of NYHA functional Class III or ambulatory Class IV heart failure symptoms on optimal recommended medical therapy. (Level of Evidence: B) 2) For patients with LVEF less than or equal to 35% with NYHA functional Class III or ambulatory Class IV symptoms who are receiving optimal recommended medical therapy and who have frequent dependence on ventricular pacing, CRT is reasonable. (Level of Evidence: C) Class IIb 1) For patients with LVEF less than or equal to 35% with NYHA functional Class I or II symptoms who are receiving optimal recommended medical therapy and who are undergoing implantation of a permanent pacemaker and/or ICD with anticipated frequent ventricular pacing, CRT may be considered. (Level of Evidence: C)

”

Unanswered Questions

Unanswered questions regarding the indications for CRT include:

1. The identification of patients who would definitely benefit from CRT (i.e. reducing the number of non-responders). Different imaging modalities and dyssynchrony parameters may accurately reveal mechanical dyssynchrony and therefore predict a CRT responder, especially in patients with a narrow QRS complex.
2. Further confirmatory evidence regarding the benefit of atrioventricular ablation versus pharmacological rate control in optimizing the clinical benefits is needed. In addition to atrioventricular and Ventricular-Ventricular optimization, other device based changes need to be explored so as to optimize the benefits of CRT.