Transcatheter aortic valve implantation: new hope in the management of valvular heart disease

Transcatheter Mitral Valve Replacement for Treating Native Mitral Valve Disease: Current Status

Transcatheter mitral valve replacement is increasingly being used as a treatment for high-risk patients who have native mitral valve disease; however, no comprehensive studies on its effectiveness have been reported. We therefore searched the literature for reports on patients with native mitral valve disease who underwent transcatheter access treatment. We found 40 reports, published from September 2013 through April 2017, that described the cases of 66 patients (mean age, 71 ± 12 yr; 30 women; 30 patients with mitral stenosis, 34 with mitral regurgitation, and 2 mixed) who underwent transcatheter mitral valve replacement. We documented their baseline clinical characteristics, comorbidities, diagnostic imaging results, procedural details, and postprocedural results. Access was transapical in 41 patients and transseptal in 25. The 30-day survival rate was 82.5%. The technical success rate (83.3% overall) was slightly but not significantly better in patients who had mitral regurgitation than in those who had mitral stenosis. Transapical access procedures resulted in fewer valve-in-valve implantations than did transseptal access procedures (P=0.026). These current results indicate that transcatheter mitral valve replacement is feasible in treating native mitral disease. The slightly higher technical success rate in patients who had mitral regurgitation suggests that a valve with a specific anchoring system is needed when treating mitral stenosis. Our findings indicate that transapical access is more reliable than transseptal access and that securely anchoring the valve is still challenging in transseptal access.

Late coronary ischemıc syndromes assocıated wıth transcatheter aortıc valve ımplantatıon: A revıew of mechanıstıc and clınıcal aspects

In the past years, transcatheter aortic valve implantation (TAVI) has emerged as a promising option for the treatment of aortic valve pathologies particularly in the the presence of surgically high-risk situations. Importantly, a variety of specific procedural complications including acute coronary osteal occlusion, though very rare, has been reported in major clinical studies. However, little is known about the late impact of TAVI on coronary system at the macro and microvascular levels.

On the other hand, clinical studies as well as real life experiences have shown variable rates of acute coronary syndrome (ACS) readmissions among TAVI recipients in the short and long terms. Within this context, it may be suggested that even though late coronary ischemic events arising after TAVI, to some extent, appears to be spontaneous or attributable to certain stressors, TAVI may also have the potential to directly account for, accelerate or contribute to the evolution of these ischemic events on follow-up. Accordingly, the present review primarily focuses on potential association of TAVI with late coronary ischemic syndromes along with a particular emphasis on its mechanistic basis and clinical implications among TAVI recipients.

Development of a Novel Human Cell-Derived Tissue-Engineered Heart Valve for Transcatheter Aortic Valve Replacement: an In Vitro and In Vivo Feasibility Study

Transcatheter aortic valve replacement (TAVR) is being extended to younger patients. However, TAVR-compatible bioprostheses are based on xenogeneic materials with limited durability. Off-the-shelf tissue-engineered heart valves (TEHVs) with remodeling capacity may overcome the shortcomings of current TAVR devices. Here, we develop for the first time a TEHV for TAVR, based on human cell-derived extracellular matrix and integrated into a state-of-the-art stent for TAVR. The TEHVs, characterized by a dense acellular collagenous matrix, demonstrated in vitro functionality under aortic pressure conditions (n = 4). Next, transapical TAVR feasibility and in vivo TEHV functionality were assessed in acute studies (n = 5) in sheep. The valves successfully coped with the aortic environment, showing normal leaflet motion, free coronary flow, and absence of stenosis or paravalvular leak. At explantation, TEHVs presented full structural integrity and initial cell infiltration. Its long-term performance proven, such TEHV could fulfill the need for next-generation lifelong TAVR prostheses.