Bocks, Martin L.

Platinum-containing stents are commonly used in humans with hypercholesterolemia, whereas preclinical stent evaluation has commonly been performed in healthy animal models, providing inadequate information about stent performance under hypercholesterolemic conditions. In this investigation, we used an ApoE−/− mouse model to test the impact of hypercholesterolemia on neointima formation on platinum-containing implants. We implanted 125 μm diameter platinum wires into the abdominal aortas of ApoE−/− and ApoE+/+ mice for 6 months, followed by histological and immunofluorescence examination of neointimal size and composition. It was found that ApoE−/− mice developed neointimas with four times larger area and ten times greater thickness than ApoE+/+ counterparts. Neointimas developed in the ApoE−/− mice also contained higher amounts of lipids quantified as having 370 times more coverage compared to ApoE+/+, a 3-fold increase in SMCs, and a 22-fold increase in macrophages. A confluent endothelium had regenerated in both mouse strains. The ApoE−/− mice experienced luminal reductions more closely resembling clinically relevant restenosis in humans. Overall, the response to platinum arterial implants was highly dependent upon the atherogenic environment.

BackgroundThe most common reason for reintervention after a Björk modification of the Fontan procedure, in which the right ventricle (RV) is incorporated into the pulmonary circulation by connecting the right atrial (RA) appendage to the RV directly or with an extra‐anatomic graft, is obstruction or regurgitation of the RA–RV connection. Transcatheter implantation of a valved stent is an appealing option for the treatment of RA–RV conduit dysfunction in these patients. In the present study, we assessed early and intermediate results after transcatheter valve implantation within an obstructed or regurgitant RA–RV modified Fontan pathway.MethodsThrough a retrospective multicenter registry, we collected data from 16 patients with a modified Fontan circulation who were treated with percutaneous Melody or Sapien valve implantation for dysfunction of an extra‐anatomic RA–RV conduit or valve.ResultsAll patients had successful and uncomplicated implantation of a Melody (n = 15) or Sapien 3 (n = 1) valve with hemodynamic and, in most cases, clinical improvement. During a median follow‐up of 3.3 years, 3 patients died of cardiovascular causes unrelated to the procedure or the valve, and no major valve dysfunction was observed.ConclusionPercutaneous transcatheter valve deployment to treat a dysfunctional RA–RV connection after a Björk modification of the Fontan procedure is a viable alternative to surgery, with low procedural risk, and appears to offer good early and intermediate results.© 2016 Wiley Periodicals, Inc.

Background— Off-label use of transcatheter aortic and pulmonary valve prostheses for tricuspid valve-in-valve implantation (TVIV) within dysfunctional surgical tricuspid valve (TV) bioprostheses has been described in small reports. Methods and Results— An international, multicenter registry was developed to collect data on TVIV cases. Patient-related factors, procedural details and outcomes, and follow-up data were analyzed. Valve-in-ring or heterotopic TV implantation procedures were not included. Data were collected on 156 patients with bioprosthetic TV dysfunction who underwent catheterization with planned TVIV. The median age was 40 years, and 71% of patients were in New York Heart Association class III or IV. Among 152 patients in whom TVIV was attempted with a Melody (n=94) or Sapien (n=58) valve, implantation was successful in 150, with few serious complications. After TVIV, both the TV inflow gradient and tricuspid regurgitation grade improved significantly. During follow-up (median, 13.3 months), 22 patients died, 5 within 30 days; all 22 patients were in New York Heart Association class III or IV, and 9 were hospitalized before TVIV. There were 10 TV reinterventions, and 3 other patients had significant recurrent TV dysfunction. At follow-up, 77% of patients were in New York Heart Association class I or II ( P <0.001 versus before TVIV). Outcomes did not differ according to surgical valve size or TVIV valve type. Conclusions— TVIV with commercially available transcatheter prostheses is technically and clinically successful in patients of various ages across a wide range of valve size. Although preimplantation clinical status was associated with outcome, many patients in New York Heart Association class III or IV at baseline improved. TVIV should be considered a viable option for treatment of failing TV bioprostheses.