Worth an Arm and a Leg: The Critical Importance of Limb Ischemia

C ritical limb ischemia (CLI) represents the final stages of peripheral artery disease, reflecting impairment in tissue perfusion that leads to a threatened limb. The clinical manifestations of this condition may be broad, ranging from rest pain to severe ischemic ulceration or tissue gangrene of the extremities. Unfortunately, this condition is relatively common, with an annual incidence of 3.5 patients per 1000 and a documented age-adjusted prevalence of 1.3% in the United States. More concerning, the incidence of this condition will likely grow because up to 10% of patients with peripheral artery disease are expected to develop CLI over a 5-year period. The primary therapeutic intervention for this condition focuses on urgent revascularization to facilitate tissue salvage, through percutaneous or surgical approaches. The immediate limb salvage rates with revascularization are encouraging, although subsequent morbidity and mortality remain high, with more than one third of these patients experiencing a major adverse cardiovascular event within 3 years of their initial presentation. The need for urgent revascularization during the index presentation and the subsequent risk of adverse events make the treatment of CLI incredibly costly to patients and the healthcare system as a whole. In the article by Mustapha et al in this issue of the Journal of the American Heart Association (JAHA), the authors describe the clinical and financial burden of CLI among Medicare patients. Using administrative billing codes, the authors identified all Medicare beneficiaries (72 199) treated for this condition in a single calendar year (2011). Procedural codes for endovascular revascularization, surgical revascularization, or amputation were also collected to stratify the clinical outcomes and costs on the basis of the initial treatment strategy. The authors found a similar incidence of CLI in this population as previously reported, with 0.3% of the cohort having a new diagnosis during the study period. The clinical outcomes of these patients were poor regardless of initial management strategy, with only 46% survival and 87% freedom from amputation over a 4-year follow-up period. Stratified by clinical presentation, rates of amputation and mortality were proportional to the acuity of presentation, increasing from patients with rest pain to those with ulcerations and highest among patients with gangrene. A propensity-matched cohort was constructed to compare outcomes among the different treatment modalities, with survival found to be comparable among patients undergoing percutaneous or surgical revascularization and significantly lower among those undergoing primary amputation. In addition to the significant personal burden, the financial costs of this condition were also calculated, with a mean expenditure of $35 700 per patient-year, totaling >$6.5 billion for the population over the entire study period. The authors should be commended for bringing additional attention to CLI, and attempting to investigate its clinical outcomes and financial costs across treatment modalities. However, the findings underscore some of the significant challenges in studying this population. CLI remains a broad diagnosis encompassing a wide range of presentations and various stages of limb threat. Billing codes were used to account for these differences, although these entities often have significant clinical overlap that is challenging to codify with administrative data alone. Furthermore, the breadth in presentations can also represent a wide range of anatomic locations for both wounds (ie, focal toe wounds or large forefoot ulcerations) and culprit lesions (ie, isolated femoral occlusions or severe multilevel atherosclerotic disease), requiring differing assessments and therapeutic approaches. The adoption of new billing codes (International Classification of Diseases, Tenth Revision, Clinical Modification [ICD-10-CM]) The opinions expressed in this article are not necessarily those of the editors or of the American Heart Association. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the US government. From the Division of Cardiology, Department of Medicine, University of Colorado, Aurora, CO (J.A.V., S.W.W.); and Division of Cardiology, Department of Medicine, Veterans Affairs Eastern Colorado Health Care System, Denver, CO (J.A.V., S.W.W.). Correspondence to: Stephen W. Waldo, MD, 1055 Clermont St, Denver, CO 80238. E-mail: stephen.waldo@va.gov J Am Heart Assoc. 2018;7:e010093. DOI: 10.1161/JAHA.118.010093. a 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.