P6 a heart of stone: a case of apolipoprotein a–i cardiac amyloidosis treated with heart transplant

Abstract A 56–year–old woman was referred to our Unit for advanced heart failure refractory to pharmacological therapy with poor functional status (NYHA class IV, INTERMACS profile 4–5). She had a history of restrictive and hypokinetic cardiomyopathy secondary to autosomal dominant hereditary Apolipoprotein A–I (APOA1) amylodosis caused by Leu75Pro mutation, detected both in her sister and brother. An ICD was placed for cardiac arrest due to ventricular fibrillation. She was hospitalized in our unit to evaluate non–conventional heart failure therapies. ECG showed a sinus rhythm with low QRS voltages and pseudo–infarct pattern with QS waves in V1 towards V3. Laboratory testing revealed a BNP of 625 ng/L, creatinine of 1.47 mg/dL with an estimated GFR of 40 ml/min/1.73m2. Transthoracic echocardiography showed a non–dilated left ventricle (LVEDD 50 mm, LVEDV 70 ml/m2) with concentric hypertrophy (IVS/PW 15/15 mm) and granular sparkling myocardium, global hypokinesia with severely reduced left ventricular ejection fraction (LVEF 28%) and restrictive filling. The right ventricle was dilated with reduced function (TAPSE 12 mm). Moderate mitral and tricuspid regurgitation were also reported, with estimated systolic pulmonary pressure of 40 mmHg. Right heart catheterization showed a RAP of 14 mmHg, mPAP of 31 mmHg, PCWP of 25 mmHg, PVR of 2.2 wood units and a CI of 1.49 l/min/m2; after reversibility testing with intravenous nitrate, mPAP fell to 25 mmHg, PCWP was 18 mmHg, PVR 1.86 WU and CI improved to 1.94 l/min/m2. She was dependent on inotropes (dobutamine 4 mcg/Kg/min). In multidisciplinary team, LVAD placement as a bridge was excluded for severe right ventricular dysfunction and she was listed for heart transplant in 2A emergency status. Notably, screening colonoscopy showed polypoid amyloid deposition in the bowel. Macroscopic examination of explanted heart showed thickening of both ventricles, valves and papillary muscles; histopathologic examination revealed intramural amyloid accumulation. Immunohistochemistry confirmed that amyloid deposits were specifically stained with an anti–APOA1 antibody. Postoperative course was characterized by necessity of hemodialysis, which was stopped in day 26. No amyloidosis recurrence was detected at endomyocardial biopsies up to 6 months. In selected patients with cardiac amyloidosis, heart transplantation can be an effective therapeutic option with outcomes similar to those transplanted for other causes of heart failure.