Autogenous infrainguinal bypass outcomes inferior in Hispanics

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Researchers from the Brigham and Women’s Hospital and Harvard Medical School in Boston, US, have released a 22-year study that reports Hispanic patients have poorer outcomes following infrainguinal bypass grafting for the treatment of peripheral arterial disease.

Results showed that of all the study participants, Hispanics had a higher rate of bypass graft failure and amputation after revascularisation compared to Caucasians. In an analysis that accounted for a myriad of important variables affecting limb salvage after bypass, Hispanic ethnicity was found to be independently predictive of eventual amputation. Details of the study appear in the Society for Vascular Surgery’s June 2009 issue of the Journal of Vascular Surgery.


“Despite our attempts to treat all patients very aggressively for severe lower extremity ischaemia through revascularisation to prevent amputation, limb preservation at five years was 80% in Hispanics, 84% in African-Americans, and a 91% in Caucasians,” said Michael Belkin, chief of the division of vascular and endovascular surgery.


Researchers said they embarked on this study when they noticed some of the hospital’s Hispanic patients seemed to demonstrate an aggressive form of peripheral artery disease that was difficult to treat with infrainguinal bypass grafting, the “gold standard” for severe lower extremity ischaemia. They also said there was very little information available about peripheral artery disease in the Hispanic population and, in particular, little data on the outcomes of lower extremity bypass grafting in these patients.


Belkin explained that 1,646 consecutive patients who participated in the study (1,408 Caucasians, 57 Hispanics and 181 African-Americans) underwent autogenous infrainguinal reconstructions. He added Hispanic patients, like African-Americans counterparts, often required a bypass at younger age and more commonly had diabetes in comparison to Caucasians. African-Americans and Hispanics also had severe atherosclerosis below the level of knee and therefore required bypass operations lower down the leg, which are more technically demanding.


In comparison to Caucasians, “Hispanics required additional interventional procedures or operations to maintain adequate blood flow through these grafts,” said Belkin. “From our analysis of factors which contribute to graft failure, it appears that a preponderance of young patients and females, both known risk factors for graft failure, in our Hispanic population may have contributed to the initial graft failures in these patients.”


In addition to Hispanic ethnicity, independent predictors of eventual limb loss included the severity of ischaemia at presentation: comorbidities including diabetes and chronic renal insufficiency, female gender, age of less than 65 years, and the use higher-risk conduit or bypass.


Medication use (including antiplatelet drugs and anticoagulants) as well as surgical approach was equivalent between groups, and there were no differences in technical success, short-term complication rates or surveillance for problems in these bypass grafts between ethnicities.


This study is important, according to researchers, because Hispanics are the fastest growing demographic in the United States (currently at 45 million and expected to grow to 103 million by 2050) and comprise 25%of the US population.


“Our data provides evidence of outcome disparities in Hispanics treated aggressively for peripheral artery disease,” said Belkin. “Further investigation with regard to biologic and social factors is required to delineate the reasons for these inferior outcomes in Hispanic patients.”