Nitrites/Nitrates in Heart€Failure With Preserved Ejection Fraction

TAVI in Italy during the study period. After having acknowledged that most of patients treated with TAVI were at low or intermediate risk, we therefore labeled this finding as “worrying,” in light of the lack of evidence supporting the role of TAVI in this particular population up to mid-2012. However, growing evidence coming from randomized controlled trials (2) and first reports of new-generation transcatheter valves (3) have created many expectations for the future of TAVI. We respectfully disagree with Dr. Spadaccio and colleagues when they state that none of the current devices used for TAVI consider in detail the anatomic characteristics of the aortic root. Besides the fact that the authors of the letter do not provide any explanation for this statement, we believe that transcatheter valves have been accurately designed and developed to fit well to the aortic root and calcified valves. In addition, new-generation TAVI devices have incorporated features to address the limitations of the first-generation devices (i.e., outer skirt, easier positioning, repositionability, and retrievability). We concur that annular calcification represents an important issue of TAVI, being usually responsible for paravalvular regurgitation or annular injury after valve deployment. However, with increased understanding of mechanisms associated with such complications and integration of new devices and tailored prosthesis sizing, clinical outcomes of TAVI have shown to compare favorably with the latest surgical series (—2-4). In fact, according to our knowledge, all the current evidence indicates that TAVI is at least noninferior compared with SAVR (—2-4). The study by Biancari et al. (4) included TAVI procedures performed in a single center at a very early stage of the local program and with firstgeneration devices, thus justifying the suboptimal results reported in the TAVI cohort. Indeed, the most recent TAVI series report (3) on in-hospital mortality of 1% to 2%, and significant paravalvular regurgitation rate of less than 5%. In terms of valve hemodynamics, Dr. Spadaccio and colleagues indicated better performances of surgical bioprostheses, obtained thanks to valve decalcification. However, previous reports are all consistent in stating that patient–prosthesis mismatch is more frequent and more often severe after SAVR than TAVI (5). In conclusion, in light of the promising results of TAVI in high-risk populations and the expected reduced rates of complications related to the increased operators’ experience and the improved designs of the devices, future exploratory trials should investigate the reproducibility of TAVI results achieved in the high-risk patients also in those not completely fulfilling a strict definition of “high-risk.”