Refractory Anemia and Pigment Nephropathy in a Case with Mitral Prosthesis

Abstract

We present a case of refractory microangiopathic hemolytic anemia with pigment nephropathy in a case of paravalvular leak, emphasizing an early detailed evaluation of anemia in a patient with a prosthetic valve despite having an alternative etiology, which is completely reversible if treated adequately.

Case

A 60-year-old man underwent mitral valve replacement with 27 mm TTK Chitra Heart Valve (TTK Healthcare Limited, India) for rheumatic severe calcific mitral stenosis 19 years back. He was on therapeutic anticoagulation. However, he presented with functional class II dyspnea for one year. He was found to have refractory severe anemia. Blood investigation showed severe anemia (5 g/dL), high erythrocyte sedimentation rate (110 mm/h), and acute kidney injury (serum creatinine 3.9 mg/dL) with brown color urine, granular cast, and positive urine hemoglobin. Peripheral blood smear showed normocytic normochromic anemia, few microcytes, many fragmented RBCs and polychromatophils, and few nucleated red blood cells (Figure 1A). Plasma was noted to have a deep brown color. Total bilirubin was 3.4 mg% with indirect hyperbilirubinemia (3 mg%). Hepatic enzymes were minimally elevated. Serum lactate dehydrogenase was 9,735 IU/L (normal 81–234 IU/L) and the serum iron profile was within normal limits. C-reactive protein and procalcitonin were normal. He had sterile urine and blood. The echocardiogram revealed mild paravalvular mitral regurgitation, normal mitral prosthetic valve gradient, severe calcific aortic stenosis with moderate aortic regurgitation, and pulmonary hypertension (Figure 1B). Transesophageal echocardiogram showed moderate paravalvular mitral regurgitation through a crescent-shaped dehiscence around the prosthetic valve (Figure 1C and D, Videos 1–3). Hence the diagnosis of paravalvular leak-related refractory hemolytic anemia and hemoglobinuria-associated acute nephropathy was made. He underwent double valve replacement in the aortic and mitral positions. Within one month hemoglobin became 10 g/dL and creatinine 1.4 mg/dL. A similar case of stress-related hemolysis and consequent pigment-related nephropathy due to the prosthetic mechanical mitral valve has been reported by Conjeevaram et al. ¹ Another case of renal hemosiderosis post mitral valve repair has also been reported by Lee et al. ² However, refractory severe anemia was absent in both the cases. This case emphasizes an early detailed evaluation of anemia in a patient with a prosthetic valve to rule out paravalvular leak-related hemolytic anemia and hemoglobinuria-associated pigment nephropathy, despite having an alternative etiology, which is completely reversible if treated adequately.^3–5

Figure 1.

Note: LAA—Left atrial appendage; MPV—Mitral prosthetic valve.

Video 1. 2D-transoesophageal Echocardiogram at Zero Degrees Showing Moderate Paravalvular Mitral Regurgitation.

Video 2. 2D-transoesophageal Echocardiogram at 126 Degrees Showing Moderate Paravalvular Mitral Regurgitation.

Video 3. 3D-transoesophageal Echocardiogram Showing the Crescent-shaped Defect Around Mitral Valve Prosthesis.