SAN FRANCISCO — Results from 2 new studies in diabetes-related foot complications indicate how vital it is for healthcare professionals to adopt a multidisciplinary team approach when it comes to managing this often-neglected complication of diabetes.
The findings were reported at the American Diabetes Association (ADA) 2014 Scientific Sessions earlier this week.
In the first study, a retrospective look back at 10 years of treatment of underserved populations in a single center, Merribeth Bruntz, DPM, from the Denver Health Medical Center, Colorado, reported a staggering reduction in the number of amputations after she established a limb-salvage program in her institution.
In a second presentation, Laura McEwan, PhD, from the University of Ann Arbor, Michigan, described how amputations were significantly associated with death in the Translating Research Into Action for Diabetes (TRIAD) study. Somewhat surprisingly, this applied to minor amputations of the toe and forefoot as well as to major amputations.
Session chair Paul Kim, DPM, from Georgetown University School of Medicine, Washington, DC, toldMedscape Medical News the 2 new studies validate prior findings and point to the importance of developing a national treatment plan for diabetic foot.
“One of the difficulties in diabetic foot care in the US is the lack of a cohesive treatment plan, so everyone does everything differently based on the resources available to them,” he explained. There are so many disciplines doing wound care, including physicians, nurses, physical therapists, podiatrists, general surgeons, and different specialists, “that it actually muddies the water a little bit because everybody brings a little bit [of a] different toolbox to the game,” he observed.
Hence the need for a uniform, multidisciplinary approach: “If you have the right members, then you have a more comprehensive and cohesive treatment plan for the patient, and if that can be rolled out nationally, I think our amputation numbers will significantly decrease, as demonstrated here by a single institution [in Denver].”
Dr. Kim is hopeful that the establishment of the US National Diabetic Foot Registry, which is about to be launched, will help in this aim. “This is a new incentive just to look at if we are doing things correctly — there’s really been no robust registers in the US, anyway, that show that things work or don’t work, and that needs to be done so we can improve patient outcomes in general,” he said.
“The foot is a neglected area anatomically, but I think it’s gaining much more prominence. I was sitting in this session 3 years ago and there were literally 3 or 4 people in the audience, and today you saw it’s a little bit more of an interest, not only nationally but globally,” he added. “And I think things will improve further with good ambassadors for diabetic foot ulcer care — and we have many, in many different disciplines, who are traveling across the country and across the world discussing this really important and growing issue.”
Nothing Fancy: Just Working Together
Dr. Bruntz told how, when she began work in July 2004 as the first podiatrist at Denver Health Medical Center, a safety-net hospital system that serves a diverse patient population, there were no diabetic-foot clinics, no focused model of care for inpatients or outpatients, and no established limb-salvage program, and nearly all amputations were performed by general and orthopedic surgeons.
“In 2000 there was nearly a 50-50 chance that if you came in with a diabetic-foot infection you would lose your foot; it was abysmal,” she explained.
“In 2004, I started working with folks interested in forming a multidisciplinary team,” she added, noting that prior to her engagement, HbA1c levels were not even being measured in patients admitted with diabetic-foot complications, and there was no outpatient clinic.
By 2006, a program with simple processes of care was established, involving scheduled foot exams, patient education, vascular evaluation, footwear, and wound care, and surgery was performed by podiatrists, where possible, she explained. In 2008, a second podiatrist was added to the team.
A multidisciplinary approach was also developed involving specialists in infectious disease, medicine, and interventional cardiology, with a protocol for the use of antimicrobial therapy and novel endovascular techniques employed in the revascularization of patients.
In order to compare amputation rates before the program was established and afterward, outcomes in 451 patients with diabetes who underwent lower-extremity amputation from 2000–2011 were retrospectively analyzed.
“Seventy percent of patients also had coronary artery disease, and 14% end-stage renal disease,” Dr. Bruntz noted. In addition, 35% of the population had a history of substance abuse, with 62% being tobacco users, while 31% had no history of either. Almost 60% had no insurance, and the remainder were almost exclusively Medicare or Medicaid patients. The average age was 55.9 years, 72.5% of patients were male, and the average HbA1c was 9%.
Her results showed that during the years 2000–2005, in which there was no established limb-salvage program, limbs were lost an average of 36.3% of the time. Upon establishing a limb salvage program (2006–2011) limbs were lost an average of 11% of the time (P < .001).
There was no statistical significance between limb loss during any of the years when compared with diagnosis, comorbidities, social history, HbA1c, insurance status, or patient demographics, she noted.
“We didn’t do anything fancy, but we all worked together,” she concluded.
Dr. Kim said: “There are lots of studies across the globe now discussing the multidisciplinary approach in the decrease of major amputations, so this validates other people’s experiences, particularly in challenging populations.”
In her presentation, Dr. McEwan said the aim of her trial, TRIAD, was to examine the impact of diabetes-related foot complications on 10-year mortality, independent of other demographic and biologic risk factors, in a racially and socioeconomically diverse population.
There were 6692 patients with diabetes in the prospective observational study in managed care. Foot complications were assessed using administrative claims data, and the National Death Index was searched for deaths over 10 years of follow-up (2000–2009).
At baseline, there were 55 cases (1%) of Charcot neuro-osteoarthropathy, 205 cases (3%) of diabetic foot ulceration with debridement, and 101 cases (2%) of amputation with or without diabetic foot ulceration.
Mortality was 29%.
One encouraging observation, said Dr. McEwan, was that, in this managed-care population, access to high-quality care appeared to attenuate previously reported associations between black race and amputations.
In the analysis, Charcot neuro-osteoarthropathy and diabetic foot ulceration with debridement were associated with an increased risk for mortality; however, the association was not significant in fully adjusted models.
But amputation was a robust independent predictor of death, associated with a significant, almost 85% increased risk for mortality in fully adjusted analysis (hazard ratio [HR], 1.84). Most of the deaths — just under 50% — were due to cardiovascular disease.
In further sensitivity analyses, Dr. McEwan revealed that even minor amputations were associated with an almost 50% increased mortality risk (HR, 1.48), a somewhat surprising finding.
Amputation Is Not a Natural State
In conclusion, she said that lower-extremity amputation is associated with very high 5- and 10-year mortality rates (39% and 67%, respectively). This is “much higher” than for breast cancer (10% and 17%) and somewhat on a par with colorectal cancer (36% and 42%).
“Once you have an amputation, you go down a not very healthy road,” she concluded.
Dr. Kim agreed. “Amputation is not an outcome,” he stressed. “It’s not a natural state.”
“The 5- and 10-year mortality rates [associated with amputations for diabetic foot] have been shown consistently throughout many different studies as being fairly poor, greater than 80% in some cases,” he told Medscape Medical News.
“It was…disappointing [here] to see that minor amputations had no better outcome — you would suspect that they would do better, but apparently not. But I think that if you look at the natural course of the disease, these patients die of cardiovascular disease — it doesn’t matter what you do to their extremity, they all die of CVD. I guess we should expect it, but we would hope it would be better.”