Kelsey Mendell
New York Institute of Technology College of Osteopathic Medicine,
United States of America
Abstract Title: Enoxaparin as Alternative Long-term Therapy for Mechanical Mitral Valves
Biography: Kelsey N. Mendell is a third-year medical student currently attending the New York Institute of Technology in New York, USA who has completed a Master of Science degree in medical sciences from Brown University and a Bachelor of Arts degree in biology with a minor in chemistry from the University of Pennsylvania. This abstract was completed in coordination with Adithi Chandra, a high school student at Sanford School in Hockessin, DE, USA under the guidance of principal investigator Dr. Robin A. Horn, MD in the department of cardiology at Christiana Care Health System in Newark, DE, USA.
Research Interest: Current standard of care in preventing mechanical mitral valve thrombosis consists of a warfarin-based regimen. However, managing patients intolerant to warfarin safely and effectively is a unique challenge. Data on long-term low molecular weight heparin, specifically enoxaparin, are limited. We offer a successful long-term anticoagulation strategy for a patient with a mechanical mitral valve with warfarin intolerance. The patient is a 67-year-old male who underwent mitral valve repair with subsequent redo surgery. His medical history is significant for atrial fibrillation, chronic diastolic heart failure, severe pulmonary hypertension, renal transplant due to chronic kidney disease and cirrhosis. Initially on warfarin, the patient was hospitalized seven times in one year with severe gastrointestinal bleeding and highly variable INRs. He underwent multiple endoscopies, which revealed gastric ectasia, portal gastropathy, and gastric ulcers. Warfarin was switched to once daily enoxaparin with anti-factor Xa monitoring due to recurrent bleeding and inability to maintain a therapeutic INR range. Due to the patient’s advanced renal disease with a GFR of 30 mL/min and fluctuating creatinine levels, a fixed dose enoxaparin regimen was not feasible. Long-term enoxaparin use relied on maintaining anti-Xa levels between 0.8-1.2 U/mL. Levels were measured 3-4 hours post-injection, checked weekly initially and later bimonthly. Although there was no standardized recommendation on proper dose adjustment, based on limited published data, this formula was utilized to calculate dose changes: New dose = [(Current dose) × (Goal anti-Xa level)]/(Current anti-Xa level). Notably for fourteen months, the patient was successfully managed without significant change in his mitral valve gradient or major bleeding before expiring from pneumonia. Enoxaparin may be a safe and effective long-term anticoagulation option for warfarin-intolerant patients with mechanical mitral valves, provided there is careful anti-Xa monitoring and dose adjustment. Further studies or registries are needed to strengthen evidence and refine management for this high-risk population.