Abstract 19245: Heart of Stone: A Mysterious Case of Diastolic Dysfunction

Abstract

A 27 year old Somali female initially presented with renal failure and a creatinine of 10mg/dl. A kidney biopsy showed crystalline nephropathy and she was initiated on hemodialysis. A year later while she was pregnant she had multiple heart failure admissions. Echocardiograms (echo) showed normal ejection fraction (EF). A month after delivery she was admitted again with heart failure. Vital signs were stable with elevated JVP and a pansystolic murmur at the apex. Chest x ray showed pulmonary edema. Echo showed moderately concentric left ventricular hypertrophy (LVH) with an EF of 40% and severe mitral regurgitation (MR). Doppler echo showed restrictive filling pattern. Pulmonary artery pressure (PA) was 99 mm of Hg + right atrial pressure (RA) with dilated vena cava. Repeat echocardiogram post ultrafiltration of just 1 liter of volume reduced PA pressures from 99 mm+RA to about 35 mm Hg+ RA with a simultaneous reduction in MR, demonstrating marked preload dependency of left sided filing pressures. Her myocardium demonstrated an echodense speckled reflection and infiltrative cardiomyopathy was suspected. EKG showed LVH making amyloidosis unlikely diagnosis. Right ventricular endomyocardial biopsy showed extensive deposition of calcium oxalate crystals in myocardium. Further tests showed increased serum oxalate level: 140 μmoles/L (ref. upto 27), increased urinary oxalic acid excretion:171 μgm (ref. < 57) and increased urine glycolate: 101 μg/mg Cr (ref. < 79) . Liver biopsy showed very low AGT (Alanine glyoxylate aminotransferase) activity of 3.0 μmol/h/mg protein (Ref. 19.1-47.9) along with negative AGT immunoreactivity . These results confirmed diagnosis of primary hyperoxaluria type 1 (PH1) . She was started on intense hemodialysis regimen and underwent a deceased donor combined liver-kidney transplantation (CLKT). Repeat echo 6 months later shows normal EF, normal PA pressures, regression of infiltrative process with improvement in diastolic function. This is a rare case of PH1 with cardiac involvement leading to progressive infiltrative restrictive cardiomyopathy and recurrent heart failure. Early recognition of the disease is important because CLKT may achieve long-term survival and regression of cardiomyopathy.