Diagnostics & Imaging Week Contributing Writer

ATLANTA– Like many medical device trade shows, the showcasing of new and innovative technology is an important aspect of the annual American College of Cardiology (ACC; Bethesda, Maryland) scientific sessions, held at the Georgia World Congress Center last week.

Technologies that afford cost containment or cost saving measures, while clearly becoming of greater interest in the world of healthcare, are far from the most important topic at the ACC or other conferences. However, coupled with important reimbursement decisions, these cost saving devices or procedures are beginning to achieve positive publicity.

In late December, Cambridge Heart (Bedford, Massachusetts) reported that the Centers for Medicare & Medicaid Services (CMS) had proposed a national coverage determination which stated that microvolt T-Wave alternans (MTWA) diagnostic testing is to be covered for the evaluation of patients at risk of sudden cardiac death (SCD). An SCD is a potentially lethal cardiac arrhythmia triggered initially by very rapid beating in the ventricles.

This proposed decision, which was expected to be finalized last week, was issued following six months of analysis and a 30-day comment period during the summer of 2005. CMS conducted a comprehensive clinical evidence review citing numerous studies of MTWA and suggested that there is adequate evidence to conclude that MTWA testing can improve net health outcomes and is reasonable and necessary for Medicare patients who are candidates for implantable cardioverter defibrillator (ICD) placement.

Importantly, CMS said that "ICDs should not be perceived as or projected to be ideal technology and . . . responsible use of ICDs should be encouraged."

MTWA is a simple, noninvasive, 30-minute test developed over a decade ago as a diagnostic tool to measure extremely subtle beat-to-beat fluctuations in a person's heartbeat, called T-wave alternans. These very tiny heartbeat variations are detected in any clinical setting where titration of the heart rate is possible. And over the past couple of years, an extensive body of solid clinical evidence has mounted, proving that MTWA is s highly accurate way to assess which patients are at risk of an SCD event.

For example, in mid-December 2005, the Journal of the American College of Cardiology published a study, "Microvolt T-Wave Alternans and the Risk of Death or Sustained Ventricular Arrhythmias in Patients with Left Ventricular Dysfunction," demonstrating that MTWA is highly effective at separating individuals at very low risk of SCD from those at high risk. The authors concluded: "MTWA can identify not only a high-risk group but also a low-risk group unlikely to benefit from ICD prophylaxis."

The population studied was similar to the individuals studied in the well-publicized Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), published in the Jan. 20, 2005, issue of The New England Journal of Medicine. Another study, released in September 2004, had proved that MTWA could be effective stratifying risk for another group of patients in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) population.

The significance?

MTWA offers a highly accurate tool to determine which patients are the most appropriate to receive an ICD.

There is no debate that an ICD is highly effective in terminating an SCD event before it kills the patient. However, the cost of ICD therapy has become a major concern to insurers.

According to the recent report "Medical Supplies and Devices: 2006 Outlook," written by the investment banking firm Bank of America (New York), the ICD market in the U.S. in 2005 reached about $4.2 billion and is projected to grow at about 15% to 20% annually through 2010. These figures only include the cost of the ICD and they do not add in physician fees or hospital costs incurred for implantation. Adding in those costs would increase overall ICD expenditures another 60% or higher.

According to various studies, only about 20% of ICD implants actually are called upon to restore the patient's normal heart rhythm, indicating that this is a very expensive insurance policy for the healthcare system in general and insurers in particular. In its proposed coverage decision, CMS said that "since the large proportion of patients who receive an ICD never received any therapy from their device, consideration of additional risk stratification methods would be reasonable."

Support for the cost efficacy of MTWA was delivered at the ACC in a talk titled "Cost-Effectiveness of ICD Therapy and Risk Stratification With Microvolt T Wave Alternans Testing in the MADIT-II Eligible Population," by Paul Chan, MD, from the VA Center for Practice Management & Outcomes Research and the University of Michigan (Ann Arbor). The study, which evaluated MADIT-II eligible patients and analyzed outcomes of expected cost, quality-adjusted life years and incremental cost-effectiveness concluded that "risk stratification with MTWA testing in MADIT-II patients improves the cost-effectiveness of ICDs. Implanting defibrillators in all MADIT-II type patients, however, is not cost-effective, with one-third of patients deriving little additional benefit at great expense."

Chan added that "the data suggests that the use of risk stratification make good sense, potentially saving $700 million per year in the MADIT II population alone."

Further support for MTWA occurred last week as well, as Cambridge Heart announced that Aetna, one of the nation's leading healthcare insurers, covering 14.8 million people nationally, had agreed to provide its members with coverage for MTWA. While not surprising that Aetna had determined the MTWA made good cost-sense, the fact that they issued their decision before the final CMS determination came as a positive surprise.

In its decision Aetna stated that it considers "microvolt T-wave alternans diagnostic testing . . . medically necessary for the evaluation of persons at risk of sudden cardiac death who meet criteria for implantable cardioverter defibrillator placement."

In a meeting with some investors attending the ACC, sponsored by Prudential Equity Group (New York), two physicians intimately involved with ICD implants and MTWA voiced their support for this technology.

David Rosenbaum, MD, director of the Heart and Vascular Center at Metro Health Medical Center (Cleveland) and Otto Constantini, MD, director of clinical trials at Metro Health, indicated that "the real question today is not who needs an ICD implant but who does not."

Rosenbaum further noted that with the tremendous cost of an ICD placement, "the need for the early identification of both low-risk and high-risk patients is growing steadily."

These physicians are co-principal investigators for the ABCD (Alternans Before Cardioverter Defibrillator) trial by St. Jude Medical (St. Paul, Minnesota), designed to evaluate and compare the positive predictive value of a MTWA to that of an electrophysiology study in patients with ischemic heart disease, left ventricular dysfunction and non-sustained tachycardia. Participants are undergoing both the TWA test and EP study, receiving an ICD for either positive result or both.

The results of ABCD, which may be released either later this year or early next year, will be a very important study because it could demonstrate that noninvasive MTWA is equivalent to a far more invasive EP study in predicting a first-time episode of SCD.

David Chazanovitz, CEO of Cambridge Heart, who indicated that his five-plus years as CEO have been "tumultuous," said he is pleased to see the extensive clinical investigations showing the enormous value of MTWA.

Responding to a question as to whether MTWA could ultimately become a requirement, not just a recommendation, before an ICD implant, Chazanovitz said that is unlikely in the near future. But if it does occur, he said it would be "nirvana" for MTWA and his company.