Recent clinical data have begun to clearly define when to implant cardiac rhythm devices and which patients will benefit the most from them.
A cute heart failure accounts for more than one million primary hospitalizations annually, and more than three million contributing hospitalizations. It is the leading cause of hospitalization in patients over the age of 65—which will grow as the population ages.
Advanced heart failure (HF) patients with low ejection fractions (EF) are candidates for cardiac-resynchronization therapy (CRT). CRT has been shown to be an effective treatment, but not preventive, in this patient population. The MADIT-CRT trial, however, found that the use of CRT with an implantable cardioverter defibrillator (CRT-D)—compared to the use of ICDs alone—could prevent the development of HF in asymptomatic patients with low EF and wide QRS complex.
MADIT-CRT found that in these at-risk patients CRT-D devices reduced HF events by 41 percent and HF or death by 34 percent. “These striking results were significantly better in women than in men,” says principal investigator Arthur J. Moss, MD, from the University of Rochester Medical Center in Rochester, N.Y.
But how do these results translate into real-life clinical practice? Not very well, says Mariell L. Jessup, MD, from the University of Pennsylvania School of Medicine in Philadelphia. In an editorial, Jessup wrote that the MADIT-CRT results indicate that 12 patients would need to be treated to prevent a single HF event ( N Engl J Med 2009; 361:1394-1396). As a result, she questions the economic value of the treatment. “An analysis based on data from the five longest CRT randomized trials revealed that the incremental cost per quality-adjusted life-year gained was $32,822. The incremental cost effectiveness of combined CRT with ICD devices, as compared with CRT devices alone, has been markedly higher in most analyses,” Jessup wrote. “Is this money that could be spent more wisely?”
She concluded that any expanded indication for CRT in less-symptomatic patients should be confined to patients with a QRS duration of more than 150 msec and in whom previous marked symptoms have been controlled with optimal medical therapy. In response, Moss says that “one ought to separate science from cost effectiveness,” adding that the price points could potentially change over time.
“Cost effectiveness always improves with time. The cost of the devices is currently expensive because they are used in relatively few patients. However, if the devices gained more widespread acceptance, they could come down in price considerably,” he says.
The Heart Rhythm Society (HRS) will examine data from MADIT-CRT to determine if changes to guidelines are in order, says Richard Page, MD, president of the society and chair of cardiology at University of Washington School of Medicine in Seattle. “It’s a large, well-conducted trial with impressive trends for heart failure patients that could expand indications for these devices,” Page says.
Moss and colleagues submitted these data in November to the FDA for premarket approval of CRT-D in class 1 and II heart failure patients. If the FDA grants approval, Medicare will most likely reimburse for this resynchronization therapy, Moss says.
Despite positive trends with implanted devices, concerns exist about complication rates. New results from the REPLACE registry, delivered at the 2009 American Heart Association conference, showed a six-month major complication rate of 15.3 percent in 1,000 patients with pacemaker and ICD replacements that included planned lead additions or revisions (see table). The overall infection rate (major and minor) was low (1.1 percent), while the peri-operative major complication rate was 2.4 percent (cardiac perforation and pneumothorax topped the list). Researchers also found a high (18.7 percent) complication rate for left ventricular lead additions or revisions in 750 patients.
“There is an increased recognition of the risk associated with these procedures, but there also are large trials indicating clear benefits,” Page says. “Unlike previous years, 2009 did not see any massive recalls due to problems with the devices.”
Most notably, in late 2007, Medtronic suspended global distribution of its Sprint Fidelis family of defibrillation leads because of the potential for lead fractures. At the time, approximately 268,000 Sprint Fidelis leads had been implanted worldwide.
Complication rates may