The ACC Foundation (ACCF), American Heart Association and Heart Rhythm Society on Sept. 10 jointly released a focused update to the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities. Chief among the updates are expanded indications for cardiac resynchronization therapy (CRT) and device follow up.
When it comes to CRT, the updated guidelines clarify and provide recommendations about which patients are most likely to benefit from the therapy based on recent clinical trials, such as the MADIT-CRT trial, RAFT trial, REVERSE trial and MIRACLE ICD II trial. "These are patients who have previously been excluded from receiving CRT, but studies have shown they can benefit from this procedure," said Cynthia M. Tracy, MD, FACC, chair of the writing group and associate director of cardiology at George Washington University. "The updated guidelines extend and clarify current best practices and will continue to evolve as technology advances."
Specific recommendations include:
- Limitation of the Class I indication to patients with QRS duration ≥ 150 ms;
- Limitation of the Class I indication to patients with left bundle-branch block (LBBB) pattern;
- Expansion of Class I indication to New York Heart Association (NYHA) class II (and with LBBB with QRS duration ≥ 150 ms); and
- The addition of a Class IIb recommendation for patients who have left ventricular ejection fraction (LVEF) ≤ 30 percent, ischemic etiology of heart failure, sinus rhythm, LBBB with a QRS duration ≥ 150 ms, and NYHA class I symptoms.
Also included in the update are changes related to follow-up and remote monitoring of cardiovascular implantable electronic devices (CEIDs). According to the writing group, clinical trials have shown remote monitoring to be a safe alternative to office visits to evaluate CIEDs. "Compared with in-person office visits to evaluate CIEDs, remote monitoring leads to early discovery of clinically actionable events, decreased time to clinical decision in response to these events, and fewer office visits," they note. The update offers suggestions for the minimum frequency of in-office and remote monitoring depending on the type of CIED. However, the authors note that issues such as lead malfunction, unreliable battery life indicators, and other device or lead recalls may influence clinical decisions and change the appropriate minimum follow-up. Original sections of the 2008 guidelines that remain unchanged, include hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia/cardiomyopathy, genetic arrhythmia syndromes, congenital heart disease, primary electrical disease and terminal care.
The focused update writing group included experts in device therapy, cardiovascular care, internal medicine, cardiovascular surgery, and pediatric and adult electrophysiology. The guidelines were also developed in collaboration with the American Association for Thoracic Surgery, Heart Failure Society of America, and Society of Thoracic Surgeons. Related appropriate use criteria (AUC) for ICDs and CRT are currently in development that will help to further interpret the best science and apply it to various clinical scenarios. "The AUC document will help define when it is reasonable to perform a procedure and, importantly, when it is not reasonable," the writing group said.