Heart of Stone: Cardiogenic Shock from Myocardial and Mitral Valve Calcification with Systolic Anterior Motion (SAM) Defect after Valve Replacement in a Patient on Chronic Hemodialysis (CHD)

Introduction: Myocardial & valve calcification has been descibed in CHD autopsy studies but has rarely been reported to be a clinical cause for CHF in CHD pts. We describe a pt who after 16 years of dialysis developed severe dyspnea & mitral stenosis from annular calcification(C) She had HFpEF & later developed cardiogenic shock & SAM after mitral replacement with severe LV outflow track obstruction. Autopsy showed severe myocardial C & 50 % myocaridal fibrosis, a new cause of clinical HFpEF in CHD pts. Case Description: A CHD pt with years of PTH > 2000 pg/ml, hypercalcemia and CaPhosphorous(P) product 54-123 developed dyspena with mitral stenois with a 16 mmHg gradient. She was on CHD from 1988-90 & then 1992 -2006. After PTH removal in 1997 she had severe hypocalcmia ,PTH < 1.0 pg/ml, & she got over 2000 mcg of iv calcitriol & 11,100 grams of CaP binders from 1992 to 2006. Cardiac studies showed a small heart with a cardiothoracic ratio of .36, LVEF 70 %, severe mitral gradient of 14-16 mmHg, LVH, & pulmonary artery presssure of 79 mmHg & mild tricuspid regurg. The coronary arteries had minimal changes. At surgery severe mitral annular calcification allowed only a pediatric St.Jude's valve. On day 3 she devleoped shock requiring fluids & 3 pressors. TEE showed marked SAM with severe obstruction of the LV ouflow track, severe pulmonay hypertension & severe tricuspid regurg & RV failure. LVEF was 65%. At death autopsy showed a small heart size despite a weight of 600 gms.with diffuse myocardial C on H&E & 50 % of the myocadium had fibrosis on trichrome stains. Calcium deposits were minimal in the coronary arteries. Discussion: We conclude: 1) Diffuse myocardial C & fibrosis can occur in CHD pts from parathyroid & CaP dysrgulation & over use of calcium based P binders and IV Calcitriol. 2) Myocardial calcium causing severe fibrosis is a rare but important cause of dyspnea & HFpEF with a small heart in CHD pts. 3) SAM of the mitral valve has never been reported in CHD pts & can occur after mitral valve replacement 4) Prexisting tricuspid regurg & pulmonary hypertension are risk factors for severe RV failure after mitral valve replacement. 5) Simultaneous tricuspid valve replacement or repair may be needed in such pts receivng a mitral valve prosthesis.