NEW YORK (Reuters Health) – The American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines has issued a focused update of its 2008 guidelines for device-based therapy of cardiac arrhythmias.
Dr. Andrew E. Epstein of the University of Pennsylvania, Philadelphia, vice chair of the 2012 Writing Group, told Reuters Health by email, “The updated Device-Based Therapy Guideline focuses on cardiac resynchronization therapy since this is the area in which there have been new, well-done studies that allow us to refine our identification of patients most likely to respond to this intervention.”
“The 2012 update highlights the importance of bundle branch morphology and duration of the QRS signal on the electrocardiogram to predict benefit, and expands indications to patients with less severe degrees of heart failure than previously,” Dr. Epstein said.
Among the most significant of such changes are limitation of the Class I recommendation to patients with QRS duration 150 ms or more and limitation of the Class I recommendation to patients with left bundle-branch block pattern (LBBB). An addition is Class IIb recommendation for patients with a left ventricular ejection fraction (LVEF) of 30% or less, ischemic etiology of heart failure, sinus rhythm, LBBB with a QRS duration 150 ms or more, and NYHA class I symptoms.
Dr. Epstein added, “More precise advice is given for patients with atrial fibrillation, an arrhythmia that is extremely common in those with heart failure.” For example in Class IIa, benefit is now based on LVEF fraction rather than NYHA class.
“In addition,” continued Dr. Epstein, “the document also clearly defines groups of patients not likely to benefit, emphasizes that comorbidities influence outcomes and specifies who should not be prescribed resynchronization therapy.”
Such therapy is not recommended for patients with NYHA class I or II symptoms and non-LBBB pattern with QRS duration less than 150 ms.
This is also the case for patients whose comorbidities and/or frailty limit survival with good functional capacity to less than one year. The modified recommendations now include cardiac as well as noncardiac comorbidities.
Since the 2008 guideline was issued, a number of trials have shown remote monitoring to be a safe alternative to office visits for evaluating patients with cardiovascular implantable electronic devices. The report also makes suggestions for the minimum frequency of in-office and remote monitoring of patients with these devices.
The guidelines update was published online in Circulation on September 10th. The entire document is available at the URL given below.