High Reintervention and Amputation Rates After Outpatient Atherectomy for Claudication.

Outpatient use of atherectomy for peripheral arterial disease has grown rapidly and outcomes are poorly understood. We analyzed outcomes of atherectomy done for claudication, comparing office and hospital outpatient settings. Analysis of Medicare Part B claims data was performed for incident femoral-popliteal or tibial-peroneal atherectomy from 2012 to 2014. Longitudinal analysis assessed services 18 months before, during, and up to 18 months after the incident peripheral vascular intervention (PVI). Differences between office-based and hospital outpatient-based settings were assessed using χ2 and Fisher exact tests. Comparing procedure settings, significant differences in race (femoral-popliteal: P = .04, tibial-peroneal: P = .001), chronic renal failure (femoral-popliteal: P = .002), and hypertension (femoral-popliteal: P = .01, tibial-peroneal: P = .006) were found. Nine hundred twenty-four patients undergoing femoral-popliteal atherectomy were analyzed (262 office based, 662 hospital outpatient based); 42.7% of office-based and 36.9% of hospital outpatient-based femoral-popliteal atherectomy patients had repeat PVI within 18 months ( P = .10). Major amputation was performed in 2.3% and 3.2% of patients in office and hospital outpatient settings, respectively ( P = .47). Four hundred twenty-three patients undergoing tibial-peroneal atherectomy were analyzed (202 office based, 221 hospital outpatient based); 46.5% of office-based and 38.9% of hospital outpatient-based tibial-peroneal atherectomy patients had repeat PVI within 1 year ( P = .11). Major amputation was performed in 5.0% and 8.1% of patients in office and hospital outpatient settings, respectively ( P = .19). Our study demonstrates higher than expected rates of major amputation for patients undergoing peripheral arterial atherectomy with regard to previously reported rates. Further studies may be required to prove the efficacy and safety of atherectomy for occlusive disease in the femoral-popliteal and tibial-peroneal segments to ensure outcomes are not worse than the natural history of medically managed claudicants.

The disproportionate growth of office-based atherectomy.

OBJECTIVE: The purpose of this study was to evaluate the trends in procedure volume, clinical sites of care, and Medicare expenditure for peripheral vascular interventions (PVIs) for lower extremity occlusive disease since the Centers for Medicare and Medicaid Services instituted reimbursement policy changes that broadened payment for procedures performed in physician-owned office-based laboratories (OBLs). METHODS: We analyzed fee-for-service Medicare claims data from 2011 to 2014 to obtain the frequency of use of PVI by type, care setting, and physician specialty. We also assessed changes in the total Medicare cost for PVI by setting. RESULTS: There was a 60% increase in atherectomy cases among Medicare beneficiaries between 2011 and 2014. During the same period, OBLs experienced a 298% increase in atherectomy volume vs a 27% increase in hospital outpatient settings and an 11% decrease for inpatient hospital settings. In 2014, OBLs were the most common setting for atherectomy. Nonatherectomy PVIs grew more modestly at just 3% but also experienced site of care shifts. Vascular surgeons and cardiologists accounted for the majority of office-based PVIs in 2014. Total Medicare costs for PVIs increased 18% from 2011 to 2014. Hospital inpatient costs declined 1%, whereas costs for hospital outpatient PVIs increased by 41% and physician office costs increased by 258%. CONCLUSIONS: The migration of revascularization procedures for lower extremity peripheral arterial occlusive disease continues from the inpatient to the outpatient setting and especially to OBLs. Increased use of atherectomy in all segments of the lower extremity arterial system has been observed, particularly in OBLs, without substantial evidence in the literature of increased efficacy compared with standard angioplasty with or without stenting. Generous Medicare reimbursement for in-office atherectomy procedures is likely contributing to the volume shifts observed.

Key Concepts in Critical Limb Ischemia: Selected Proceedings from the 2015 Vascular Interventional Advances Meeting.

Over 500,000 patients each year are diagnosed with critical limb ischemia (CLI), the most severe form of peripheral artery disease. CLI portends a grim prognosis; half the patients die from a cardiovascular cause within 5 years, a rate that is 5 times higher than a matched population without CLI. In 2014, the Centers for Medicare and Medicaid Services paid approximately $3.6 billion for claims submitted by hospitals for inpatient and outpatient care delivered to patients with CLI. Although significant advances in diagnosis, treatment, and follow-up of patients with CLI have been made, many challenges remain. In this article, we summarize selected presentations from the 2015 Vascular Interventional Advances Conference related to the modern demographics, diagnosis, and management of patients with CLI.

Promiscuity of MHC class Ib-restricted T cell responses.

Murine infection with the Gram-positive intracellular bacterium Listeria monocytogenes activates CD8(+) T cells that recognize bacterially derived N-formyl methionine peptides in the context of H2-M3 MHC class Ib molecules. Three peptides, fMIGWII, fMIVIL, and fMIVTLF, are targets of L. monocytogenes-specific CD8(+) T cells. To investigate epitope cross-recognition by H2-M3-restricted CD8(+) T cells, we deleted the sequence encoding fMIGWII from a virulent strain of L. monocytogenes. Infection with fMIGWII-deficient L. monocytogenes unexpectedly primed CD8(+) T cells that stain with fMIGWII/H2-M3 tetramers and lyse fMIGWII-coated target cells in vivo. Because the fMIGWII sequence is nonredundant, we speculated that other bacterially derived Ags are priming these responses. HPLC peptide fractionation of bacterial culture supernatants revealed several distinct L. monocytogenes-derived peptides that are recognized by fMIGWII-specific T cells. Our results demonstrate that the dominant H2-M3-restricted CD8(+) T cell population, although reactive with fMIGWII, is primed by other, non-fMIGWII peptides derived from L. monocytogenes. Although this degree of Ag receptor promiscuity is unusual for the adaptive immune system, it may be a more common feature of T cell responses restricted by nonpolymorphic MHC class Ib molecules.