Medtronic (NYSE:MDT) plans to use new study results to ask the FDA to expand the indication for its cardiac resynchronization therapy devices, to include patients with atrioventricular block and left ventricular systolic dysfunction.
A recent study published in the New England Journal of Medicine showed that simultaneously pacing the lower chambers of the heart with a CRT device significantly improves heart failure symptoms and quality of life in some patients with heart disease.
“Biventricular pacing was superior to conventional right ventricular pacing in patients with atrioventricular block and left ventricular systolic dysfunction with NYHA class I, II, or III heart failure,” the study’s authors conclude in the April 25 edition of NEJM.
Medtronic, which last week traded barbs with rival Boston Scientific (NYSE:BSX) in an advertising slap-fight over the true longevity of Medtronic’s new cardiac rhythm management implants, presented findings from the BLOCK HF clinical trial over the weekend at the Heart Rhythm Society’s 34th Annual Scientific Sessions.
The BLOCK HF trial showed a marked reduction in heart failure-related symptoms for patients with atrioventricular block and left ventricular systolic dysfunction at 6, 12, 18 and 24 months treated with bivalve pacing as opposed to conventional right-ventricular pacing, Fridley, Minn.-based Medtronic said.
Additionally, the data revealed a considerable improvement in quality of life among bivalve-paced patients at 6 and 12 months, the company says.
"[Right-ventricular] pacing has been considered the gold standard for decades in treating patients with [atrioventricular] block; however, findings from the BLOCK HF trial continue to exhibit better overall outcomes with biventricular pacing via CRT devices for these patients," said Dr. David Steinhaus, general manager of heart failure products for Medtronic’s cardiac rhythm disease management division, in prepared remarks.
More than 800,000 Americans have atrioventricular block, Medtronic notes. While right-ventricular pacing via a single or dual chamber pacemaker helps restore heart function in patients with atrioventricular block (in which the electrical signals do not travel between the top and bottom chambers of the heart), smaller studies suggest that in patients with both atrioventricular block and left ventricular dysfunction, right-ventricular pacing may escalate the progression of heart failure.
"These new data add to the growing body of evidence supporting the use of biventricular pacing for treating patients who have atrioventricular block and left ventricular dysfunction who are indicated under current clinical guidelines for permanent right-ventricular pacing with a pacemaker," lead investigator Dr. Anne Curtis of the University at Buffalo School of Medicine and Biomedical Sciences added in a statement. "The BLOCK HF findings have previously demonstrated that biventricular pacing delays disease progression, prevents heart failure-related events and preserves cardiac function in this patient population. The findings presented today confirm two additional, yet equally important clinical benefits associated with this innovative therapy – symptom and quality-of-life improvement."