ICD AUC stress clinical judgment, need for more trials

Combining research-derived data, practice guidance and common clinical experience, the American College of Cardiology Foundation, the Heart Rhythm Society and other specialty societies released appropriate use criteria (AUC) for implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT). The AUC were published online Feb. 28 on the societies’ websites and will appear later in the Journal of the American College of Cardiology.

ICDs and CRT are effective in primary and secondary prevention of sudden cardiac death, but the societies acknowledge concern about both overutilization and underutilization. Overutilization, for example, may occur in patients with cognitive impairment or significant comorbidities, and underutilization in patients who may benefit from the therapy but for whom little data is available because they are excluded from clinical trials.

The document attempts to weave together trial data and experiential evidence while leaving enough flexibility for the exercise of clinical judgment in particular cases. The writing committee of 10 members developed 369 real-world clinical scenarios, which were then considered by a technical panel of 20. The technical panel was comprised of experts whose main source of income was not tied to ICD/CRT, who evaluated the evidence and designated use as Appropriate, May Be Appropriate or Rarely Appropriate for each scenario. This is a change from prior AUC terminology, which designated indications as Appropriate, Uncertain or Inappropriate.

Appropriate uses were those supported by clinical trial findings or clinical experience, but the authors pointed out that an Appropriate rating did not mean that an ICD was the proper treatment in that case, merely that it was a treatment that should be considered in the circumstances. Scenarios with limited clinical evidence supporting implantation, extenuating circumstances that may favor implantation or disagreement between members of the technical panel were rated May Be Appropriate. If the technical panel found indications of harm or no clinical evidence supporting implantation, the indication was designated Rarely Appropriate. The writers designated 45 percent of the scenarios they considered as Appropriate for ICD implantation, 33 percent as May Be Appropriate and 22 percent as Rarely Appropriate.

“The goal of this document is to help inform medical decisions and assist clinicians and stakeholders in understanding areas of both consensus and uncertainty, while identifying areas where there are gaps in knowledge that warrant further research,”  writing committee co-chair Andrea M. Russo, MD, of Cooper University Hospital in Camden, N.J., said in a release.

The authors emphasized that the May Be Appropriate category indicated that clinical judgment was called for: “The wide breadth of scenarios rated as May Be Appropriate raises the importance of recognizing the role of applying clinical judgment to decision making when encountering patients who broadly meet these criteria, as well as for the importance of advocating for future clinical trials to better inform decision-making in these scenarios,” they wrote.

“It is anticipated that physicians practicing good evidence-based care will implant a mix of cases meeting both Appropriate and May Be Appropriate categories. However, if there are marked variations in patterns when compared with national benchmarks further examination of the patterns of care might be helpful in identifying explanations for these variations,” the authors wrote. The document also emphasized that the AUC were likely to be amended as the results of implementation studies and more trial data became available.

The AUC scenarios cover six areas of practice: ICDs for primary prevention, ICDs for secondary prevention, comorbidities, CRT devices, generator replacement and single vs. dual-chamber ICDs.

Did the societies go far enough in revising appropriate use terminology? J. Jeffrey Marshall, MD, president of the Society for Cardiovascular Angiography and Interventions, offers his assessment in a Q&A with Cardiovascular Business.