Warfarin induced leukocytoclastic vasculitis: an extraordinary side effect.

Warfarin is one of the most commonly used anticoagulants in the management of thromboembolic events. Herein we report a rare case of warfarin induced leukocytoclastic vasculitis in a patient with history of rheumatic heart disease and a mechanical mitral valve prosthesis who presented with heart failure and palpable purpura. Upon clinical suspicion of cutaneous small vessel vasculitis, a comprehensive laboratory panel was performed. Warfarin induced vasculitis was suspected when withdrawal of warfarin, due to rising INR, led to improvement of the skin lesions. The diagnosis was finally confirmed when re-instatement of warfarin reproduced the skin lesions and a skin biopsy showed evidence for leukocytoclastic vasculitis with eosinophilic infiltration. A third of cases of leukocytoclastic vasculitis are due to drug hypersensitivity which being a diagnosis of exclusion with varying manifestations, requires a high index of clinical suspicion. Since drug induced leukocytoclastic vasculitis may affect multiple organ systems and even cause mortality, clinicians must be aware of this rare adverse event, promptly discontinue the drug, and commence anti-inflammatory or immunosuppressive treatment when necessary.

Creatinine versus cystatin C to estimate glomerular filtration rate in adults with congenital heart disease: Results of the Boston Adult Congenital Heart Disease Biobank.

BACKGROUND: Glomerular filtration rate is a key physiologic variable with a central role in clinical decision making and a strong association with prognosis in diverse populations. Reduced estimated glomerular filtration rate (eGFR) is common among adults with congenital heart disease (ACHD). METHODS: We conducted a prospective cohort study of outpatient ACHD ≥18 years old seen in 2012-2017. Creatinine and cystatin C were measured; eGFR was calculated using either the creatinine or cystatin C Chronic Kidney Disease-Epidemiology Collaboration equation (CKD-EPICr and CKD-EPICysC, respectively). Survival analysis was performed to define the relationship between eGFR and both all-cause mortality and a composite outcome of death or nonelective cardiovascular hospitalization. RESULTS: Our cohort included 911 ACHD (39 ±â€¯14 years old, 49% female). Mean CKD-EPICr and CKD-EPICysC were similar (101 ±â€¯20 vs 100 ±â€¯23 mL/min/1.73 m2), but CKD-EPICr estimates were higher for patients with a Fontan circulation (n = 131, +10 ±â€¯19 mL/min/1.73 m2). After mean follow-up of 659 days, 128 patients (14.1%) experienced the composite outcome and 31 (3.4%) died. CKD-EPICysC more strongly predicted all-cause mortality (eGFR <60 vs >90 mL/min/1.73 m2: CKD-EPICysC unadjusted HR = 20.2 [95% CI 7.6-53.1], C-statistic = 0.797; CKD-EPICr unadjusted HR = 4.6 [1.7-12.7], C-statistic = 0.620). CKD-EPICysC independently predicted the composite outcome, whereas CKD-EPICr did not (CKD-EPICysC adjusted HR = 3.0 [1.7-5.3]; CKD-EPICr adjusted HR = 1.5 [0.8-3.1]). Patients reclassified to a lower eGFR category by CKD-EPICysC, compared with CKD-EPICr, were at increased risk for the composite outcome (HR = 2.9 [2.0-4.3], P < .0001); those reclassified to a higher eGFR class were at lower risk (HR = 0.5 [0.3-0.9], P = .03). CONCLUSIONS: Cystatin C-based eGFR more strongly predicts clinical events than creatinine-based eGFR in ACHD. Creatinine-based methods appear particularly questionable in the Fontan circulation.