Government agencies such as the Centers for Medicare and Medicaid Services (CMS) have demonstrated a growing responsiveness to evidence-based medicine by expanding coverage of treatments and therapies based on scientific research and clinical trials. Such is the case with the prophylactic (or preventive) use of implantable cardioverter defibrillators (ICDs).
The use of ICDs has dramatically reduced the incidence of sudden cardiac death since clinical trials began about 10 years ago. Numerous studies have shown that ICDs are effective in reducing mortality by 28 percent in patients who had survived a prior heart attack and, as a result, were at very high risk of sudden cardiac death. With such strong evidence, the medical community rapidly accepted use of ICDs in these high-risk patients.21
However, there was controversy regarding prophylactic ICD implantation in patients who had not experienced a heart attack but were considered to be at risk of sudden cardiac death because of preexisting heart disease. As studies conducted over the past three years produced a solid body of evidence showing a reduction in mortality ranging from 23 to 46 percent due to prophylactic ICDs in such patients, attitudes have gradually shifted in favor of implantation.22
In January 2005, CMS expanded coverage of ICDs for prophylactic use. At the same time, CMS mandated the establishment of a national registry to collect specific data for each case. The agency believes this registry will help to facilitate clinical decision-making and ensure optimal patient care when used in conjunction with clinical studies.23
This heralds a new evidence-based approach for CMS, which indicated that future agency decisions to expand Medicare coverage would probably require the collection of additional clinical data “to ensure that . . . the coverage process reflects a systematic, science-based approach that is predictable and transparent.”24
Since the ICD field has evolved quickly, devices available today have significantly greater capabilities than those of only two or three years ago. This illustrates the challenge presented by the rapid pace of technology development and the resulting gap between the evidence available and the evidence needed to determine best practices and set policy. According to Mark A. Hlatky, professor of health research and policy and of medicine (cardiovascular) at the Stanford University School of Medicine, “The field of evidence-based medicine needs to develop sound methods to deal with this ‘moving target’ problem.”25