POS-215 A case of hemolytic uremic syndrome after mitral valve annuloplasty procedure

Abstract

Microangiopathic hemolytic anemia (MAHA) is a known complication after valve replacement with prosthetic valves. Hemolytic anemia can occur also after mitral valve repair operation, but the incidence of hemolysis complications is unknown. In this abstract, we describe a case of hemolytic uremic syndrome (HUS) after mitral valve annuloplasty, which was succesfully treated with prosthetic replacement of the valve. A 44-year-old male presented to cardiologist consultation because of the arrhytmia history 3 months ago. Initial evaluation included disease history: In 2017 the patient experienced episode of ventricular tachycardia, which was treated with infusion of amiodarone and 3 defibrillation shocks. Patient‘s medical history includes history of hypertension for 10 years, type 2 diabetes for 5 years, usage of anabolic steroids 10 years ago (patient was a heavy-lifter) and occasional cigarettes smoking. Physical examination revealed a systolic murmur in the mitral valve auscultation area. In the performed heart ultrasound a mitral valve prolapse and 3rd degree mitral regurgitation was found. It was recommended to perform a mitral valve annuloplasty with coronary artery bypass surgery with bicuspidalization of the tricuspid valve. With the consensus of the patient the following operation was performed. Right after the operation macrohematuria in the urinary bag was noticed. The patient was admitted to intensive care unit following the operation 48 hours after the operation full laboratory evaluation was performed (dynamics of lab tests are presented in the table 1). High creatinine, lactatedehydrogenase, C-reactive protein, lowering haptoglobin, hemoglobin and platelet count was found and hemolytic uremic syndrome was suspected. Ultrasound of the heart was completely norma. The patient was started on continuous venovenous hemofiltration. Because of the unknown cause of the hemolytic uremic syndrome the following laboratory tests were performed: ADAMTS-13 normal, SC5b-9 was elevated 419.6 ng/ml (normal value 200-325 ng/ml), complement system hemolytic activity CH50 test was normal. Because of the suspected thrombotic microangiopathy, kidney biopsy was performed: minimal and non-specific findings were present. On the 6 day after the operation the ultrasound of the heart was repeated and severe mitral valve regurgitation was found. It was decided to perform urgent mitral valve replacement with mechanical valve. After the operation hemolytic uremic syndrome has resolved, creatinine and urea were lowering and hemolysis has stopped. Hemolytic uremic syndrome after mitral valve repair operations in very rare. It is very unlikely, that this condition will resolve spontaneously and very close cooperation between surgeons and nephrologists is recommended to solve such cases. Further studies investigating optimal approaches and defining risk factors for hemolytic uremic syndrome after mitral valve repair operation are required.