Reddy, Prajwal

Abstract Background Amyloidosis is defined by abnormal protein folding and subsequent deposition in tissues. Cardiac involvement is usually related to misfolded monoclonal immunoglobulin light chains or misfolded transthyretin; however, apolipoprotein A-1–associated amyloidosis is a hereditary form of amyloidosis resulting from mutations in the AAPOA1 gene that can also result in cardiac amyloidosis. Although there have been advancements in noninvasive algorithms for the diagnosis of cardiac amyloidosis, endomyocardial biopsy (EMB) may still be warranted. All individuals undergoing EMB are susceptible to complications, including tricuspid valve injury resulting in severe tricuspid valve regurgitation. Case summary Our patient is a 70-year-old white man presented with symptoms of dyspnoea on exertion and decreased functional capacity, diagnosed previously with apolipoprotein A-I cardiac amyloidosis, confirmed by EMB. He developed progressive right-sided heart failure secondary to iatrogenic flail tricuspid leaflet related to the diagnostic EMB. He underwent a successful transcatheter tricuspid valve edge-to-edge repair with 4D intracardiac echocardiographic guidance. At the recent follow-up, the patient showed improved symptoms, with increased stamina, and transoesophageal echocardiography revealed a 65% ejection fraction and mild tricuspid regurgitation (TR). Discussion Tricuspid valve injury is one of the complications associated with EMB, which can result in severe TR. Transcatheter tricuspid valve edge-to-edge repair can be a useful option for patients considered too high risk for surgical intervention, such as those with advanced cardiac amyloidosis.

Introduction: Severe tricuspid regurgitation (TR) is associated with considerable morbidity/mortality in an elderly population with multiple comorbidities. There is interest in transcatheter interventions to manage severe TR in this population. Understanding right heart (RH) anatomy has implications for patient/device selection for transcatheter intervention. Hypothesis: We analyzed RH anatomy by CT of patients referred for TR therapy to determine transcatheter tricuspid intervention device sizing needs. Methods: Retrospective Mayo Clinic study of 29 patients considered for intervention of severe TR from 3/1/2016-12/15/2020; echocardiogram and CT angiogram obtained in all patients. Results: Mean age was 83±8 (83% female), 100% had atrial fibrillation, and 62% had chronic kidney disease ≥3a. 97% were symptomatic, 93% were prescribed loop diuretics, and 24% had device leads. Mean tricuspid annular plane systolic excursion 16.8±4.5 mm, effective regurgitant orifice area (EROA) 81±33 mm 2 , and cardiac index 2.6±0.6 L/min/m 2 . 41% had at least moderate right ventricular (RV) dysfunction with a mean RV systolic pressure of 46±16 mmHg. Patients receiving intervention had significantly larger EROA (101±33 v. 63±22 mm 2 , P=0.033), shorter tricuspid leaflet tenting length (6.5±3.0 v. 8.9±2.7 mm, P=0.042), and smaller annuloplasty diagnostic perimeter during diastole (120.1±16.6 v. 131.1±7.4 mm, P=0.041). Intervention patients tended to have better right ventricular function, smaller RV and IVC size, and more severe symptoms. Max tricuspid annulus diameter in systole and diastole was 51±5 and 53±7 mm, respectively. Conclusions: Severe TR patients referred for transcatheter intervention present with severe RH enlargement with a large proportion having tricuspid annulus dimensions outside the range for current devices available in clinical trials. These data have implications for device development/selection and procedural feasibility.