Invited Commentary

Abstract

Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world.–Albert Einstein, 1929 While Einstein wanted to describe imagination as the driving force behind the search for knowledge, the widespread use of a transcatheter aortic valve replacement (TAVR) is an example for the replacement of knowledge by imagination. It is quite astonishing that a novel technique like TAVR with at first a non-inferiority status [1Smith C.R. Leon M.B. Mack M.J. et al.Transcatheter versus Surgical Aortic-Valve Replacement in High-Risk Patients.N Engl J Med. 2011; 364: 2187-2198Crossref PubMed Scopus (4768) Google Scholar] over the established methods, shown in only 1 prospective randomized trial (by the way, sponsored by the same company selling the novel devices) with a very limited number of participants, could gain such relevance in patient treatment as well as in the scientific discussion. The superiority [2Adams D.H. Popma J.J. Reardon M.J. et al.Transcatheter aortic-valve replacement with a self-expanding prosthesis.N Engl J Med. 2014; 370: 1790-1798Crossref PubMed Scopus (2023) Google Scholar] of TAVR over conventional AVR could only later be shown in an, again, company-sponsored trial. The paper of Ribeiro and colleagues [3Ribeiro H. Dahou A. Urena M. et al.Myocardial injury after transaortic versus transapical transcatheter aortic valve replacement.Ann Thorac Surg. 2015; 99: 2001-2009Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar] deals with 2 different TAVR techniques (transaortic versus transapical approach) regarding myocardial injury and ventricular function after the procedure. A clear message can be read between the lines, although very cautiously phrased: transaortic (TAO) TAVR is superior to transapical (TA) TAVR because TAO TAVR leads to less myocardial injury and to a better left ventricular recovery. Interestingly, this does not lead to better clinical outcomes after 30 days or 12 months in the TAO TAVR group, as one would expect knowing the influence of high cardiac biomarkers on long-term outcomes after valve surgery [4Paparella D. Guida P. Caparrotti S. et al.Myocardial damage influences short- and mid-term survival after valve surgery: a prospective multicenter study.J Thorac Cardiovasc Surg. 2014; 148: 2373-2379Abstract Full Text Full Text PDF PubMed Scopus (21) Google Scholar]. One important detail to be found in Supplemental Table 3 is not mentioned by the authors. Moderate or severe aortic valve regurgitation occurs nearly 4 times more often (nearly significantly more often) in the TAO TAVR group. Although there are data available on how high-degree aortic regurgitation worsens long-term survival [5Abdel-Wahab M. Zahn R. Horack M. et al.Aortic regurgitation after transcatheter aortic valve implantation: incidence and early outcome. Results from the German transcatheter aortic valve interventions registry.Heart. 2011; 97: 899-906Crossref PubMed Scopus (440) Google Scholar], the clinical outcomes of the 2 patient groups in this study are similar. Is it possible that higher biomarkers in the TA TAVR group and more aortic regurgitation in the TAO TAVR group balance each other? Clearly, the hypotheses of Ribeiro and colleagues [3Ribeiro H. Dahou A. Urena M. et al.Myocardial injury after transaortic versus transapical transcatheter aortic valve replacement.Ann Thorac Surg. 2015; 99: 2001-2009Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar] have to be proven “by future studies with larger sample size … to determine whether or not differences in myocardial injury … translate into significant differences in mortality…”, as the authors state themselves. Ribeiro and colleagues are to be congratulated on an excellent study inspired by their imagination, but they still have to contribute to the “limited knowledge.” Einstein again: “It’s important to go on asking questions.” Myocardial Injury After Transaortic Versus Transapical Transcatheter Aortic Valve ReplacementThe Annals of Thoracic SurgeryVol. 99Issue 6PreviewThe release of cardiac biomarkers of myocardial injury after transcatheter aortic valve replacement (TAVR) is common, but no data exist on patients undergoing TAVR through a transaortic approach. We aimed to evaluate the incidence and prognostic significance of the increase in cardiac biomarkers in nontransfemoral TAVR candidates, comparing transaortic and transapical approaches. Full-Text PDF