The Persistence of Non-Vitamin K Antagonist Oral Anticoagulants in Korean Patients with Non-Valvular Atrial Fibrillation

BACKGROUND AND OBJECTIVES: Non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly used for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), showing better efficacy and safety than warfarin. However, the rates or reasons for discontinuation of NOACs in clinical practice have not been clarified. The aim of this study was to compare 3 NOACs (apixaban, rivaroxaban, and dabigatran) with warfarin in terms of medication persistence. SUBJECTS AND METHODS: We retrospectively evaluated 1,527 patients with NVAF who had recently started taking NOACs between January 2012 and September 2015 (294 apixaban, 748 rivaroxaban, and 485 dabigatran) and compared them with 363 patients with NVAF who started taking warfarin between January 2012 and December 2013 at the Samsung Medical Center. RESULTS: The mean follow-up duration was 532 days. The discontinuation rates were higher in the 3 NOAC groups than in the warfarin group within the first year. The major causes of discontinuation were maintenance of sinus rhythm; adverse events, including all bleeding and gastrointestinal symptoms; and patients demand. The adverse event rate was lower in the warfarin group than in the 3 NOAC groups. No significant differences in thromboembolic and major bleeding events were found between the 3 NOAC groups and the warfarin group. CONCLUSION: In a single-center study, NOACs showed lower medication persistence and higher adverse event rates than warfarin during the first year.

Two Successfully Treated Cases of Pulmonary Fibrosis Due to Paraquat Poisoning

Paraquat poisoning can cause severe multiple organ failure involving the kidneys, liver, lungs, adrenals, and central nervous system. The toxic effect of paraquat on the lung manifests as pulmonary edema, hypoxia, respiratory failure, and pulmonary fibrosis. However, optimal guidelines for treatment of lung fibrosis following paraquat ingestion are not available. We experienced two cases, a 45-year-old Korean male and a 66-year-old Korean male, who visited the emergency center because of paraquat poisoning. They initially received methylprednisolone pulse therapy and cyclophosphamide. Then they experienced pulmonary fibrosis approximately 10 days after admission during renal recovery. Although steroid pulse therapy with cyclophosphamide was reported to reduce mortality due to paraquat poisoning, the side effects of cyclophosphamide treatment were concerning in our patients, who had already received cyclophosphamide. Therefore, we decided to repeat steroid pulse therapy without cyclophosphamide. Fortunately, pulmonary fibrosis in these two patients resolved after repeated steroid pulse therapy. Thus, steroid pulse therapy alone could benefit patients with lung fibrosis, who have already received steroid and cyclophosphamide treatment. Herein, we report on two cases of pulmonary fibrosis due to paraquat poisoning that were treated successfully with repeated steroid pulse therapy.

The Experience and Management of Two Cases of Metformin-associated Lactic Acidosis

Metformin, a dimethylbiguanide, is an oral antihyperglycemic drug used in treatment of type 2 diabetes mellitus. It has been reported that metformin may be associated with lactic acidosis in patients with clinical conditions such as renal failure and heart failure. Metformin-associated lactic acidosis (MALA) is a rare, but serious complication with a mortality rate of approximately 30~50%. Therefore, an aggressive treatment strategy including hemodialysis is recommended for these patients. Although continuous renal replacement therapy (CRRT) has been administered in hemodynamically unstable patients with MALA, there are few case reports describing the use of CRRT as a therapeutic modality in Korea. Here, we describe the case histories of two MALA patients who underwent treatment with CRRT.

A Case of Cryptococcal Meningitis Mimicking Hepatic Encephalopathy in a Patient with Liver Cirrhosis Caused by Chronic Hepatitis C / 대한소화기학회지

Cryptococcus neoformans, an encapsulated fungus, is an important opportunistic pathogen that can cause meningitis in immunocompromised patients. Since patients with cryptococcemia have high mortality, it is essential to make an early diagnosis and promptly initiate antifungal therapy. However, it is often very difficult to differentiate between cryptococcal meningitis and hepatic encephalopathy in patients with liver cirrhosis, and there is delay in making the diagnosis. Therefore, these patients have a particularly grave prognosis and consequently many patients die before culture results become available. In one study, starting antifungal therapy within 48 hours of the blood culture was associated with improved survival, but patients with liver cirrhosis were significantly less likely to receive antifungal therapy within 48 hours compared to those without liver cirrhosis. Recently, the authors experience a case of a 68-year-old woman with liver cirrhosis who presented with fever and a drowsy mental status. She had a previous history of having been admitted for infection-associated hepatic encephlopathy. Cryptococcal meningitis and cryptococcemia were diagnosed by spinal puncture and culture of cerebrospinal fluid. In spite of adequate treatment, the patient developed multi-system organ failure and eventually expired. Herein, we report a case of cryptococcal meningitis mimicking hepatic encephalopathy in a patient with liver cirrhosis.

Idiopathic retroperitoneal fibrosis associated with Hashimoto's thyroiditis in a patient with a single functioning kidney

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of fibroinflammatory tissue around the abdominal aorta and ureteral entrapment in most cases. Idiopathic RPF is frequently reported in association with autoimmune diseases; however, there have been few reports of idiopathic RPF associated with Hashimoto's thyroiditis. Here, we report a case of idiopathic RPF with Hashimoto's thyroiditis in a patient with a single functioning kidney, which was successfully treated by corticosteroid therapy and transient intraureteral stent insertion with a double-J catheter.