Diagnostics & Imaging Week Washington Editor

WASHINGTON – Coverage decisions handed down by Center for Medicare and Medicaid Services (CMS) decisions can spell good news or disappointment for device makers, many of which depend on Medicare reimbursement to maintain sales.

Cambridge Heart (Bedford, Massachusetts) was the recipient of favorable news when CMS recently delivered a determination in favor of the company's cardiac sensor device, dubbed the HearTwave II System, to detect low-level heartbeat variations on the order of a millionth of a volt. During a March 22 conference call discussing the decision, Cambridge Heart president and CEO, David Chazanovitz, celebrated the decision as a "very satisfying result in a year-long process of evaluating the evidence."

According to the company's web site, the device's sensors can detect subtle variations in heartbeat, known as microvolt T-wave alternans, "even in the presence of the noise typically encountered during exercise stress testing" and allow clinicians to record "up to four ECG signals from the same anatomical site."

The test is designed to establish whether any patient at risk of sudden cardiac death is a good candidate for an implanted cardioverter defibrillator (ICD).

Much of the drive behind CMS's interest in this technology comes from clinical study data that suggest that only about one in five ICDs routinely restore the patient's heart rhythm, making the $4 billion spent on ICDs in 2005 an expensive fix. The realization that a "large proportion of patients who receive an ICD never receive any therapy from their device," prompted the agency to seek "additional risk stratification methods."

Chazanovitz added that this declaration puts control of testing "into the physician's hands, and this is exactly what we asked for." He was quick to point out also that the CMS decision was contingent on the use of the company's analytical logarithm, described only as the "Spectral Analytical Method."

CMS did not approve of payment for the device's use with an alternate logarithm, known as the MMA (modified moving average).

Chazanovitz said that this was because the clinical data generated in support of the sensors is based on the use of Cambridge's algorithm and the associated interpretation criteria, and a CMS review of the literature failed to disclose any large-scale studies employing the MMA – hence, the exclusion.