Prophylactic defibrillator use cost-effective in select patients

ICD cost data get better and better as new devices surface

You may be seeing more and more implantable cardioverter defibrillators (ICDs) in use as they become smaller, cheaper, and easier to maintain. The devices are expensive - most cost between $40,000 and $60,000 for implantation. In the case of devices with a simpler one-lead system, the surface of the device case serves as the second electrode to complete the electrical circuit, and its cost is typically $20,000.

"One has to weigh the serious complications that antiarrhythmic drugs produce against the expense and complications of an ICD. We know that ICDs do work," says Les Wooldridge, RN, education coordinator of the resuscitation program at Vanderbilt University Medical Center in Nashville, TN.

Cost data on ICD therapy are continually changing as new devices - smaller and more varied - are introduced. (See photos of two ICDs currently on the market, p. 122.) In many patients, a single-chamber ICD can be implanted and tested on an outpatient basis, significantly decreasing costs.

To keep costs low, look for devices that are easy and quick to implant, shortening hospitalization. Devices with biphasic pulse waveforms enable more patients to easily meet implant criteria and increase the safety margin for all patients. Some models have an induction testing capability that makes it easy to induce fibrillation to test the device and leads during the implant procedure. Some include a programmer that communicates with the implanted device via telemetry, simplifying adjustment of therapy. Such communication also confirms that the device is performing as it should.

Investigators have demonstrated that pectorally implanted systems - those small enough to be placed in the chest area rather than the abdomen - reduce cost of implant and hospitalization by 35% over larger systems:

· lower implant costs: $32,090 vs. $38,307;

· lower convalescent charges: $5,861 vs. $12,447;

· lower total hospital charges: $53,459 vs. $71,981;

· lower professional fees for implant: $4,131 vs. $6,100;

· lower professional fees for convalescence: $1,258 vs. $2,846;

· lower total professional fees: $12,925 vs. $15,731.1

"Costs for [ICD] prophylactic therapy would be much lower if limited-function devices with enhanced longevity that required limited manufacturer support were available," says John P. DiMarco, MD, PhD, professor of medicine in the division of cardiology at the University of Virginia in Charlottesville. "New ideas are needed if ICD therapy is to become not only cost-effective but cost attractive."

Investigators report conditionally positive results in a cost analysis they ran early this year on the prophylactic use of ICDs.2 Alvin I. Mushlin, MD, and colleagues collected data on hospitalizations, emergency department and office visits, diagnostic tests, community services, medical supplies, and prescription medications used by patients randomized to either immediate ICD implantation or other, unspecified antiarrhythmic therapy. Patients were deemed eligible for the Multicenter Automatic Implantable Cardioverter Defibrillator Implantation Trial (MADIT) if they had documented nonsustained ventricular tachycardia (VT), a left ventricular ejection fraction less than 35%, and sustained VT induced at electrophysiologic study.

Initial cost higher for ICD group

The investigators found that over a four-year period, the average survival in the ICD group was 3.66 years compared to 2.80 years in the control group. The average costs for the initial hospitalizations in the ICD group were considerably higher than the non-ICD group - $44,600 vs. $18,900 - due to the expense of the device and its implantation. Subsequently, however, the control group had higher costs due to crossovers to ICDs and medications. The investigators estimated an incremental cost-effectiveness rate of $27,000 per life-year saved for the ICD group. If data from four patients in the study who went on to require expensive procedures are eliminated, the incremental cost-effectiveness rate rises to $39,600 per life-year saved. The investigators conclude that ICD implantation is cost-effective in patients who meet MADIT criteria.

"If one confined ICD use to the traditional indication of survivors of cardiac arrest or hypotensive VT, the relatively low resuscitation rates for those events would restrict the economic effects of ICD therapy," says DiMarco. However, he says, prophylactic ICD use in high-risk populations before a clinical episode of sustained arrhythmia has a much greater potential for increasing total costs. "The incremental cost ratio of $27,000 per life-year saved is within the range of medical procedures deemed acceptable by society."

DiMarco goes on to question the study authors' noninclusion of expenses associated with screening MADIT candidates. "Focusing only on costs incurred after the positive findings at electrophysiologic study have been made does not tell the entire story," he says.

AVID trial stopped because of ICD's benefits

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health stopped its Antiarrhythmics Vs. Implantable Defibrillators (AVID) trial in spring of last year because, early on, there was a significant reduction in deaths among the ICD group. The trial compared two treatment strategies for patients with life-threatening arrhythmias - ICDs and drug treatment with amiodarone or sotalol. In a statement, Claude Lenfant, MD, NHLBI director, said that the aborted study showed that "implantable cardiac defibrillators improve overall survival in patients with serious ventricular arrhythmias."

Half of the patients in the study had VT and half had ventricular fibrillation. After one year, patients in the ICD group demonstrated a 38% reduction in deaths compared to the medicated group. In years two and three, there was a 25% reduction."The implantable cardiac defibrillator is like having an emergency room implanted in your chest," said Douglas Zipes, MD, chair of the AVID steering committee.

The AVID trial determined that average charges for ICD implantation were $66,600, and it cost $34,000 to monitor a patient in the hospital for administration of antiarrhythmic drugs.

The new, smaller ICDs are implanted under the skin in the pectoral region where they monitor heart action and deliver electrical impulses to correct dangerously accelerating heartbeats. The devices do not prevent arrhythmias from starting, but they recognize them and attempt to correct them.

Leads connected to the ICD are guided through the vascular system of the heart, where they sense electrical activity, send information back to the generator, and deliver the impulses produced by the generator. A lead wire with a metal electrode at one end is implanted in the heart and carries electrical signals between the pulse generator and the heart. Systems vary according to patient need and price, but a full-featured system administers tiered therapy programmed to begin therapy with impulses of an intensity similar to those from a conventional pacemaker. If those do not override the arrhythmia, the device automatically delivers shocks of increasing intensity - usually painless - until a normal heart rate is restored. ICDs also store information collected so it can be evaluated. Some advanced models can send information over the phone to physicians.

References

1. Munger TM, Stanton MS, Shen WK, et al. Economic impact of advancing implantable cardioverter defibrillator technologies: Decreased monetary costs and earlier hospital discharge. American College of Cardiology 44th Annual Scientific Session, Sept. 9, 1994;

Williamson BD, Man KC, Niebauer M, et al. The economic impact of transvenous defibrillation lead systems. PACE 1994;17:2297-2303;

Seidl K, Hauer B, Isgro F, et al. Cost effectiveness analysis between two different nonthoracotomy ICD lead implantation techniques: Abdominal vs. subpectoral implantation sites. PACE 1994;18:1741.

2. Mushlin AI, Hall WJ, Zwanziger J, et al, for the MADIT Investigators. The cost-effectiveness of automatic implantable cardiac defibrillators: Results from MADIT. Circulation 1998;97:2129.

Suggested reading

Epstein AE, Plumb VJ, Kirk KA, et al. Pacing threshold increase in nonthoracotomy implantable defibrillator leads. J Interventional Cardiac Electrophysiology 1997;1:131-134.