Symptomatic CO following TAVI was a rare but life-threatening complication that occurred more frequently in women, in patients receiving a balloon-expandable valve, and in those with a previous surgical bioprosthesis. Lower-lying coronary ostium and shallow sinus of Valsalva were associated anatomic factors, and despite successful treatment, acute and late mortality remained very high, highlighting the importance of anticipating and preventing the occurrence of this complication.
TCEP was safe, captured embolic debris in 99% of patients, and did not change neurocognitive function. Reduction in new lesion volume on magnetic resonance scans was not statistically significant. (Cerebral Protection in Transcatheter Aortic Valve Replacement [SENTINEL]; NCT02214277).
Mitral annulus calcification (MAC) is a chronic, degenerative process in the fibrous base of the mitral valve. Although MAC was initially thought to be an age-related degenerative process, there is accumulating evidence that other mechanisms, such as atherosclerosis and abnormal calcium-phosphorus metabolism, also contribute to the development of MAC. Despite its frequency, the clinical relevance of MAC is grossly underappreciated. Indeed, MAC is associated with an increased incidence of cardiovascular disease, mitral valve disease, arrhythmias, and mortality. MAC also influences the outcomes of cardiac surgery and interventions, and its clinical relevance may well increase substantially in the forthcoming era of transcatheter mitral valve replacement. In this paper, we review the available published data to provide a consistent, clinically relevant description of MAC on the basis of contemporary imaging. We describe the pathophysiological mechanisms contributing to the formation of MAC and the clinical implications of this disease entity.
Background
Cardiosphere-derived cells (CDCs) are an attractive cell type for tissue regeneration, and autologous CDCs are being tested clinically. However, autologous therapy necessitates patient-specific tissue harvesting and cell processing, with delays to therapy and possible variations in cell potency. The use of allogeneic CDCs, if safe and effective, would obviate such limitations. We compared syngeneic and allogeneic CDC transplantation in rats from immunologically-mismatched inbred strains.
Methods and Results
In vitro, CDCs expressed MHC class I but not class II antigens or B7 costimulatory molecules. In mixed lymphocyte co-cultures, allogeneic CDCs elicited negligible lymphocyte proliferation and inflammatory cytokine secretion. In vivo, syngeneic and allogeneic CDCs survived at similar levels in the infarcted rat heart 1 week after delivery, but few syngeneic (and even fewer allogeneic) CDCs remained at 3 weeks. Allogeneic CDCs induced a transient, mild, local immune reaction in the heart, without histologically-evident rejection or systemic immunogenicity. Improvements in cardiac structure and function, sustained for 6 months, were comparable with syngeneic and allogeneic CDCs. Allogeneic CDCs stimulated endogenous regenerative mechanisms (cardiomyocyte cycling, recruitment of c-kit+ cells, angiogenesis) and increased myocardial VEGF, IGF-1 and HGF equally with syngeneic CDCs.
Conclusions
Allogeneic CDC transplantation without immunosuppression is safe, promotes cardiac regeneration and improves heart function in a rat myocardial infarction model, mainly through stimulation of endogenous repair mechanisms. This indirect mechanism of action rationalizes the persistence of benefit despite the evanescence of transplanted cell survival. This work motivates the testing of allogeneic human CDCs as a potential off-the-shelf product for cellular cardiomyoplasty.
Compared with tricuspid AS, TAVR in bicuspid AS was associated with a similar prognosis, but lower device success rate. Procedural differences were observed in patients treated with the early-generation devices, whereas no differences were observed with the new-generation devices.
TMVR with balloon-expandable aortic valves in extreme surgical risk patients with severe MAC is feasible but associated with high 30-day and 1-year mortality. Most patients who survive the 30-day post-procedural period are alive at 1 year and have sustained improvement of symptoms and transcatheter valve performance. The role of TMVR in patients with MAC requires further evaluation in clinical trials.
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