Major amputation rates low in US CLI registry

CHICAGO — Among the first 506 patients with critical limb ischemia from the PRIME registry, the rate of major amputation is low, according to findings presented at AMP: The Amputation Prevention Symposium.

Jihad A. Mustapha, MD, FACC, FSCAI, presented characteristics and outcomes from the three-center registry, the first of patients with critical limb ischemia (CLI) in North America.

“We put together the registry ... because we felt the need to collect more data on this subset of patients to understand what can we do better to improve their outcomes,” Mustapha said. “It’s designed to explore the best diagnostic and endovascular therapeutic modalities for advanced peripheral vascular disease and CLI. We have to be aggressive in treating these patients.”

Jihad A. Mustapha

Enrollment began in 2013 and has reached 626 patients, said Mustapha, director of cardiovascular catheterization laboratories at Metro Health Hospital in Wyoming, Michigan, and founder and course director of AMP: The Amputation Prevention Symposium, noting that the goal is to add sites and enroll 5,000 patients.

Data on each patient are collected at baseline, 30 days, 3 months, 6 months, 1 year, 2 years and 3 years. Mustapha presented baseline, 30-day and 1-year data from the first 506 patients (mean age, 69 years; 64% men; 92% white).

He said choice of therapy was up to each treating physician. There were 833 interventions for 1,182 target lesions, and the rates of therapies were as follows: balloon angioplasty, 92%; atherectomy, 47%; stents, 38%; chronic total occlusion procedures, 16%; procedures using a re-entry device, 3%.

Mean selective ankle-brachial index was 0.83 at 30 days and 0.77 at 1 year, whereas mean toe-brachial index was 0.46 at 30 days and 0.44 at 1 year, Mustapha said, noting that one goal of the registry is to “come up with a good analytical way of giving a diagnostic tool for the CLI patient.” Selective ankle-brachial index may be a good tool to determine when a patient should be re-evaluated or considered for revascularization, he said. Ninety-one percent of patients underwent diagnostic angiography.

The prevalence of certain symptoms in the cohort were as follows: claudication, 77.1%; rest pain, 39.3%; neuropathy (which has subsided in some patients), 26.1%; osteomyelitis, 6.7%; and cellulitis, 5.9%, he said.

The cohort includes 2.1% with Rutherford class 2, 38% class 3, 24.7% class 4, 31.7% class 5 and 3.6% class 6, although the investigators are now focusing on enrolling patients with Rutherford class 4, 5 or 6, he said.

The target limb is above the knee in 37.1% of the cohort, below the knee in 19.5% and both above and below the knee in 40.6%, according to Mustapha.

Rates of death were 1.2% at 30 days and 14.2% at 1 year. “It is true what you hear about the mortality of patients with CLI,” Mustapha said. “It is a very deadly disease.”

Rates of amputation were 0.5% at enrollment, 3.1% at 30 days and 10.4% at 1 year, and rates of major amputation were 0% at enrollment, 0.5% at 30 days and 4.2% at 1 year, he said.

The major amputation rates indicate that “there is hope,” Mustapha said. “Therapy does make a difference for CLI patients; this is a great way to show you that CLI therapy actually does prevent amputation.” – by Erik Swain

Reference:

Mustapha JA. What you should know about CLI evaluation. Presented at: AMP: The Amputation Prevention Symposium; Aug. 10-13, 2016; Chicago.

Disclosure: Mustapha reports consulting for Abbott Vascular, Bard Peripheral Vascular, Boston Scientific, Cardiovascular Systems Inc., Cook Medical, Medtronic, Spectranetics and Terumo Medical.

Editor's Note: This article was edited on August 12, 2016 to reflect a change in the data.