CHICAGO – Nonwhite ethnicity and limb infection at diagnosis predict vascular events in patients with thromboangiitis obliterans (TAO), and the latter also predicts amputation, which occurs within 10 years of diagnosis in nearly a third of patients, according to findings from a large retrospective French cohort study.
After a mean follow-up of 5.7 years, 58.9% of 224 patients with TAO – also known as Buerger’s disease – experienced a vascular event, 21.4% experienced at least one amputation, and 1.3% died, Alexandre Le Joncour, MD,at the annual meeting of the American College of Rheumatology.
The 5- and 15-year vascular event-free survival rates were 45% and 28%, respectively, and the 10- and 15-year amputation-free survival rates were 74%, and 66%, respectively, said Dr. Le Joncour of Sorbonne University, Paris.
Of note, no significant difference was seen in the vascular event-free survival rates based on tobacco use levels (more than 22 pack-years vs. 22 or fewer pack-years; HR, 1.2), he said.
Patient characteristics and clinical factors found to independently predict vascular events included nonwhite ethnicity (hazard ratio, 2.35; P = .005) and limb infection at diagnosis (HR, 3.29; P = .045). Limb infection at diagnosis also independently predicted amputation (HR, 12.1; P less than .001), he said.
“But there was no significant [association with amputation] in patients who had claudication, critical ischemia, or ischemic ulcers/necrosis,” he noted, adding that a comparison of white and nonwhite patients showed that the groups were similar with respect to epidemiologic and cardiovascular factors, clinical symptom distribution, and rates of addiction to tobacco, alcohol, and illicit drugs.
It was also clear that patients who quit using tobacco had a significantly lower risk of amputation than did those who continued using tobacco (P = .001), he said, explaining that 43 of the 48 patients who experienced amputation were current smokers, and 5 were ex-smokers at the time of amputation.
Dr. Le Joncour and his colleagues included TAO patients diagnosed between 1967 and 2016 at a median age of 36 years at the time of first symptoms, with a median of 12 months from symptom onset until diagnosis. About 76% were men, and about 83% were white. Patients with diabetes, atherosclerosis, arterial emboli, connective tissue disease, and/or thrombophilia were excluded.
Vascular events in this study were defined as “an acute worsening of the disease course requiring treatment modifications,” and included critical ischemia (35% of cases), ulcers/necrosis (33%), claudication worsening (16%), deep vein thrombosis (3%), superficial phlebitis (7%), limb infection (4%), and “other” events (2%).
Major amputation was defined as “an amputation involving the tibio-tarsian articulation for lower limbs and the metacarpophalangeal articulation for upper limbs,” he explained.
The median time to amputation was 4 years, and patients who experienced amputation had a median age of 39 years. Half of the 48 patients who experienced amputation had one amputation, nearly a third had two amputations, and 19% had three amputations. About two-thirds had minor amputations and a third had major amputations.
The findings provide important prognostic information regarding TAO, Dr. Le Joncour said, noting that long-term data on outcomes in TAO patients have been lacking.
“We found specific characteristics that identified those at highest risk for subsequent vascular complications, and these factors are not only important predictors of vascular complications or relapse, but may also serve to adjust more aggressive management and close follow-up of these patients,” he concluded.
Dr. Le Joncour reported having no disclosures.
SOURCE: Le Joncour A et al. Arthritis Rheumatol. 2018;70(Suppl 10): .