Publications

The Center for Disease Control and Prevention (CDC) recommends screening and surveillance of dialysis patients for hepatitis C virus (HCV), but there are limited data on the real life performance of confirmatory tests. We performed a cost-identification analysis of CDC recommendations using a large database of dialysis subjects. Screening and surveillance were performed according to CDC guidelines: enzyme immunoassay (EIA) testing upon entry then biannual surveillance. All positive EIA tests were confirmed by either polymerase chain reaction (PCR) or radioimmunoblot assay (RIBA). A total of 12,563 patients were tested from 1997 to 2004. By EIA, the prevalence of HCV was 8.4% and annual incidence was 0.96%. The prevalence after confirmation by RIBA and PCR was 5.8% and 4.8%, respectively. The annual incidence of hepatitis C confirmed by RIBA and PCR was 0.13% and 0.084%, respectively. Using Medicare reimbursement, the cost to screen and confirm one case of hepatitis C by RIBA was $372 versus $503 by PCR. However, the cost to identify an incident infection increased to $30,594 by RIBA and $48,622 by PCR. In the sensitivity analysis, the cost of identifying incident HCV infection dropped by 50% when the surveillance interval was extended to 1 year or when seroconversion rates for EIA occurred at 2%. Due to high surveillance cost, further studies are necessary to determine optimal intervals and settings.

BACKGROUND

Atrial arrhythmias are associated with inflammation. The cause and effect of the association are unknown.

OBJECTIVE

The purpose of this study was to test the hypothesis that atrial tachyarrhythmias contribute to inflammation.

METHODS

We performed a prospective observational study wherein C-reactive protein (CRP) and interleukin-6 (IL-6) levels from the femoral vein and coronary sinus (CS) were compared before curative ablation for atrial flutter (AFL; n = 59) and paroxysmal supraventricular tachycardia (SVT; n = 110). Follow-up levels were obtained at 1 and 6 months.

RESULTS

Peripheral levels of both biomarkers were significantly higher in the AFL group. After multivariate adjustment, only those in the AFL group who presented in AFL or atrial fibrillation (AF) had significantly elevated CRP levels (odds ratio 1.26; P = .033). Levels of each marker were similar in the CS and peripheral blood in the SVT group; in the AFL group, both CRP and IL-6 were significantly lower in the CS than in the periphery (P = .0076 and P = .0021, respectively). CRP was significantly lower a median of 47 days after AFL ablation (from a median of 6.28 mg/L to a median of 2.92 mg/L; P = .028) and remained reduced at second follow-up. IL-6 decreased across three time points after AFL ablation (P = .002). No reduction in inflammatory biomarkers was observed after SVT ablation.

CONCLUSIONS

CRP and IL-6 levels are elevated in patients presenting in AFL. Given the lower CS values in these patients, their origin appears to be systemic rather than cardiac. Because these levels significantly fall after ablation of AFL, the atrial tachyarrhythmia appears to be the cause (not the effect) of the inflammation.