Abstract P076: Sub-Optimal Medical Therapy in Hispanics Predicts Major Amputation in Chronic Critical Limb Ischemia
Background: Hispanic ethnicity has been identified as an independent predictor of major amputation after revascularization procedures for chronic critical limb ischemia (CLI), though the reasons remain unclear. We therefore examined the effect of Hispanic ethnicity and other risk factors upon major amputation rates among patients with chronic critical limb ischemia.
Methods: A single-center prospective cohort of consecutive patients diagnosed with CLI by the Vascular Service comprised the basis of this report. The primary end point was limb-salvage, defined as the freedom from an above-the-knee or below-the-knee amputation. Bivariate analysis and Cox regression models were used to assess the associations between limb salvage, ethnicity, optimal medical management, medical comorbidities, presenting ischemic severity and functional status. Optimal medical management was defined as adherence to Trans-Atlantic Conference II (TASC II) Guidelines. Significant univariate predictors of limb salvage with a p < 0.10 were entered into a multivariate Cox regression model.
Results: Between August 2010 and February 2012, 111 patients (mean age 59.5 + 10.1 (SD) years; 64 male) were evaluated with rest pain (N=42), and tissue loss (N=69). Hispanics comprised 26% of the cohort. Relative to non-Hispanics, Hispanics more frequently presented with Rutherford Class 6 ischemia (30.5% vs. 41.4%, p=0.006, χ2), and were more frequently deemed unfit for revascularization (23.2% vs. 48.3%, p=0.01, χ2). Over 80% of Hispanics presented without optimal management of medical risk factors for atherosclerosis. Univariate predictors of major amputation included Rutherford class (Hazard Ratio [HR], 2.04; 95% Confidence Interval [CI], 1.22-3.41; p=0.009); Hispanic ethnicity (HR, 3.84; 95% CI, 1.68-8.79; p=0.006); end-stage-renal disease (HR, 5.4; 95% CI, 1.52-19.5; p=0.003); sub-optimal medical management of atherosclerosis (HR, 5.63, 95% CI, 1.32-24.02; p=0.008); absence of anti-platelet medication use (HR, 2.16; 95% CI, 0.93-4.99; p=0.07); initial non-ambulatory status (HR, 2.01; 95% CI, 1.50-2.69, p<0.001); the presence of diabetes (HR, 2.98; 95% CI, 1.01-8.78; p=0.04); and hypercholesterolemia (HR, 3.52; 95% CI, 1.38-8.97). Independent predictors of major amputation included initial non-ambulatory status (HR, 2.33; 95% CI 1.64-3.33) and sub-optimal medical management of atherosclerosis (HR 7.85; 95% CI 1.71-36.1).
Conclusions: Hispanics with CLI present with more advanced ischemia that is less amenable to revascularization with a more than 3.5-fold increased risk of major amputation. Sub-optimal medical management in the overwhelming majority of Hispanics may account for the poor outcomes. Population based efforts to improve major amputation rates in CLI should target systematic interventions to improve the delivery of medical therapy, especially for the Hispanic population.
- © 2013 by American Heart Association, Inc.