EP Device Implantation Could Surge as New Data Emerge

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CVB040104Recent 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.  

CVB040104aIt’s complicated
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 vary based on who implants the devices. A retrospective review of the NCDR ICD Registry found that implantations by non-EPs (cardiologists, thoracic surgeons) were associated with a higher risk of procedural complications and
lower likelihood of receiving a CRT-D device when indicated compared with patients whose ICD was implanted by an EP (JAMA 2009;301[16]:1661-1670).

“In this era of quality, we will be examining the qualifications of the people who are performing these procedures,” Page says. “Therefore, facilities may want to carefully select who is performing the procedures.”

HRS this year released the first guidance document on lead performance in pacemakers and ICDs. The guidelines address lead malfunction and note that timely data must be issued when malfunctions occur. Emerging modalities for lead surveillance include remote monitoring and the use of the ICD Registry as a post-market surveillance tool.

Timing is everything
An ongoing debate has focused on determining the appropriate time to implant devices for certain at-risk populations, such as heart attack patients. The recent randomized, prospective IRIS study of patients with acute MI found that prophylactic ICD therapy did not reduce overall mortality or clinical features that placed them at increased risk (N Engl J Med 2009; 361:1427-1436).

The findings agree with the current guidelines, which do not recommend the use of an ICD within 40 days after an MI for the prevention of sudden cardiac death. The IRIS researchers found fewer sudden cardiac deaths in the ICD group, but the number of non-sudden cardiac deaths was higher compared to the control group.

Moss says that these data confirm previous findings. In the 2002 MADIT II trial, which compared ICD with no ICD therapy, researchers intentionally “did not enroll acute MI patients, and shied away from patients within three months of an MI, because there is so much increased risk in the infarction period.” 

In a 2004 sub-study of MADIT II, Wilbur et al found that during the first year after an MI, there was no benefit from an ICD. “If the IRIS researchers had examined these results, they may have found no need to conduct their study,” Moss says.

ICDs in EP departments
Currently, EP is inundated with a flood of activity, with the emergence of ablation for atrial fibrillation and for ventricular arrhythmias, in addition to the implantation of pacemakers, defibrillators and CRT-D devices. “The volume of device therapy has leveled off,” Moss says, “because electrophysiologists are waiting for new developments, such as MADIT-CRT.” Europe, with its different regulatory environment than the U.S., has seen a “significant increase in the use of CRT devices since the publication of the trial.” 

The guidelines suggest any patient with an ejection fraction of less than 35 percent should have a defibrillator, and there are clear mortality data to support this approach, Page notes. “It’s more difficult, however, to recommend a device implant for a moderate risk patient, especially considering the complication rates. Yet, if MADIT-CRT proves true, the patients aren’t just protected, but also feel better. Physicians and patients may be more receptive to having that conversation.”

Once these patients get a device implanted, they become a patient for life, and remotely monitoring them is the wave of the future of EP. New CPT codes have been issued for monitoring patients both in person and offsite. “Remote monitoring is a huge benefit,” Page concludes. “Right now we’re only taking in data, but in the future we’ll be able to do so much more remotely, such as re-programming devices. The technology will continue to evolve and the benefits will extend to patients, physicians and EP departments.”