Race and socioeconomic differences associated with endovascular peripheral vascular interventions for newly diagnosed claudication.

BACKGROUND: Despite guidelines cautioning against the use of endovascular peripheral vascular interventions (PVI) for claudication, more than 1.3 million PVI procedures are performed annually in the United States. We aimed to describe national rates of PVI for claudication, and identify patient and county-level risk factors associated with a high rate of PVI. METHODS: We used the Medicare claims database to identify all Medicare beneficiaries with a new diagnosis of claudication between January 2015 and June 2017. A hierarchical logistic regression model accounting for patient age, sex, comorbidities; county region and setting; and a patient race-county median income interaction was used to assess the associations of race and income with a high PVI rate. RESULTS: We identified 1,201,234 patients with a new diagnosis of claudication for analysis. Of these, 15,227 (1.27%) underwent a PVI. Based on hierarchical logistic regression accounting for patient and county-level factors, black patients residing in low-income counties had a significantly higher odds of undergoing PVI than their white counterparts (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.20-1.40), whereas the odds of PVI for black versus white patients was similar in high-income counties (OR, 1.06; 95% CI, 0.99-1.14). PVI rates were higher for low versus high-income counties in both the black (OR, 1.46; 95% CI, 1.31-1.64) and white (OR, 1.19; 95% CI, 1.12-1.27) groups. There were no significant associations of Hispanic, Asian, North American native, or other races with PVI in either low- or high-income counties after risk adjustment (all P ≥ .09). CONCLUSIONS: In the Medicare population, the mean rate of PVI of 12.7 per 1000 claudication patients varies significantly based on race and income. Our data suggest there are racial and socioeconomic differences in the treatment of claudication across the United States.

Resting energy expenditure in patients with intermittent claudication and critical limb ischemia.

OBJECTIVE: The primary aim of this study was to compare the resting energy expenditure of patients with intermittent claudication and critical limb ischemia. A secondary aim was to identify predictors of resting energy expenditure. METHODS: One hundred patients limited by intermittent claudication and 40 patients with critical limb ischemia participated in this study. Patients were assessed on resting energy expenditure, body composition, ankle brachial index (ABI), and calf blood flow. RESULTS: Patients with critical limb ischemia had a lower resting energy expenditure than patients with intermittent claudication (1429 +/- 190 kcal/day vs 1563 +/- 229 kcal/day; P = .004), and higher body fat percentage (34.8 +/- 7.8% vs 31.5 +/- 7.8%; P = .037), higher fat mass (30.0 +/- 9.3 kg vs 26.2 +/- 8.9 kg;P = .016), and lower ABI (0.31 +/- 0.11 vs 0.79 +/- 0.23; P < .001). Resting energy expenditure was predicted by fat free mass (P < .0001), age (P < .0001), ABI (P < .0001), ethnicity (P < .0001), calf blood flow (P = .005), and diabetes (P = .008). Resting energy expenditure remained lower in the patients with critical limb ischemia after adjusting for clinical characteristics plus fat free mass (1473 +/- 27.8 kcal/day [mean +/- SEM] vs 1527 +/- 19.3 kcal/day; P = .031), but it was no longer different between groups after further adjustment for ABI and calf blood flow (1494 +/- 25.2 kcal/day vs 1505 +/- 17.7 kcal/day; P = .269). CONCLUSION: Resting energy expenditure is decreased with a progression in peripheral arterial disease (PAD) symptoms from intermittent claudication to critical limb ischemia. Furthermore, patients with critical limb ischemia who are most susceptible for decline in resting energy expenditure are older, African American patients with diabetes. The lower resting energy expenditure of patients with critical limb ischemia, combined with their sedentary lifestyle, suggests that they are at high risk for long-term positive energy balance and weight gain.

Gender and ethnic differences in arterial compliance in patients with intermittent claudication.

OBJECTIVE: To assess the gender and ethnic differences in arterial compliance in patients with intermittent claudication. METHODS: A total of 114 patients participated, including 38 Caucasian men, 32 Caucasian women, 16 African American men, and 28 African American women. Patients were assessed on large artery elasticity index (LAEI), small artery elasticity index (SAEI), age, weight, body mass index, ankle-brachial index (ABI), smoking status, and metabolic syndrome components. RESULTS: Group differences were found for LAEI (P = .042), SAEI (P = .019), body mass index (P = .020), prevalence of elevated fasting glucose (P = .001), and prevalence of abdominal obesity (P = .025). Significant covariates for LAEI included age (P = .0002) and elevated triglycerides (P = .0719). LAEI (units = 10 mL x mm Hg) adjusted for age and triglycerides was 39% lower (P = .0005) in African Americans (11.4 +/- .90; mean +/- SE) than in Caucasians (15.8 +/- 0.72), whereas no significant difference (P = .7904) existed between men (13.8 +/- 0.81) and women (13.5 +/- 0.79). Significant covariates for SAEI included age (P = .0001), abdominal obesity (P = .0030), and elevated blood pressure (P = .0067). SAEI (units = 100 mL x mm Hg) adjusted for age, abdominal obesity, and elevated blood pressure was 32% lower (P = .0007) in African-Americans (2.8 +/- 0.3) than in Caucasians 4.1 +/- 0.2), and was 18% lower (P = .0442) in women (3.1 +/- 0.2) than in men (3.8 +/- 0.2). CONCLUSION: African American patients with intermittent claudication have more impaired macrovascular and microvascular function than Caucasian patients, and women have more impaired microvascular function than men. These ethnic and gender differences in arterial compliance are evident even though ABI was similar among groups, suggesting that arterial compliance provides unique information to quantify vascular impairment in patients with intermittent claudication.