Andreu M. Climent

Based on the increasingly understood regenerative capacity of the human heart and vascular system,1 cardiovascular regenerative medicine (CRM) encompasses all potential diagnostic and therapeutic strategies aimed at restoring organ health. Envisioned to enhance the innate regenerative response of cardiovascular tissues, diverse and often complementary products and strategies have been investigated (e.g. stem and progenitor cells, stromal cells, extracellular vesicles such as microvesicles and exosomes, growth factors, non-coding RNAs, episomes and other gene therapies, biomaterials, tissue engineering products, and neo-organogenesis). Despite promising results based on 20 years of research, next generation CRM treatments have yet to transform cardiovascular practice.
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\nGiven the compelling need for a thorough critical debate on the past, present, and future of CRM, the international consortium Transnational AllianCe for regenerative Therapies In Cardiovascular Syndromes (TACTICS, www.tacticsalliance.org)2 summarizes the shared vision of leading expert teams in the field (for a complete list of TACTICS members please see Annex 1). The document addresses key priorities and challenges, including basic and translational research, clinical practice, regulatory hurdles, and funding sources. The methodological procedure included the following: (i) identification of strengths, weaknesses, opportunities, and threats (SWOT analysis) by means of an open poll; (ii) distribution of the main topics between at least two worldwide key opinion leaders, who prepared proposals for each topic; (iii) open discussion and consensus on each proposal between all members of TACTICS; and (iv) review of the document by an independent committee.

BACKGROUND: Ablation of high-frequency sources in patients with atrial fibrillation (AF) is an effective therapy to restore sinus rhythm. However, this strategy may be ineffective in patients without a significant dominant frequency (DF) gradient. The aim of this study was to investigate whether sites with high-frequency activity in human AF can be identified noninvasively, which should help intervention planning and therapy. METHODS AND RESULTS: In 14 patients with a history of AF, 67-lead body surface recordings were simultaneously registered with 15 endocardial electrograms from both atria including the highest DF site, which was predetermined by atrial-wide real-time frequency electroanatomical mapping. Power spectra of surface leads and the body surface location of the highest DF site were compared with intracardiac information. Highest DFs found on specific sites of the torso showed a significant correlation with DFs found in the nearest atrium (ρ=0.96 for right atrium and ρ=0.92 for left atrium) and the DF gradient between them (ρ=0.93). The spatial distribution of power on the surface showed an inverse relationship between the frequencies versus the power spread area, consistent with localized fast sources as the AF mechanism with fibrillatory conduction elsewhere. CONCLUSIONS: Spectral analysis of body surface recordings during AF allows a noninvasive characterization of the global distribution of the atrial DFs and the identification of the atrium with the highest frequency, opening the possibility for improved noninvasive personalized diagnosis and treatment.

The international consortium TACTICS (Transnational Alliance for Regenerative Therapies in Cardiovascular Syndromes) has recently addressed key priorities in the field of cell-based therapy for cardiac repair, identifying the efficacy of translational research as one of the main challenges to ultimately improve the quality of life of patients with ischemic disease. Much of the controversy and confusion surrounding cardiac regenerative therapy stems from insufficient rigor in the conduct of preclinical studies, and there is an increasing recognition of a number of problems that undermine its quality that may contribute to translational failure. Here, we introduce well defined stages for preclinical research, and put forth proposals that should promote more rigorous preclinical work, in an effort to improve its quality and translatability. To augment the utility of preclinical research and its translation, it is necessary to (1) improve the quality of preclinical research, (2) promote collaborative efforts, and (3) enhance the sharing of knowledge and protocols. In particular, confirmatory (stage III) preclinical studies should be considered as a preamble to clinical studies and therefore must adhere to their standards of quality (including internal validity, standardization of protocols, and multicenter design). To increase transparency and minimize bias, these studies should be prospectively registered in an independent, open database. Ultimately, these recommendations should be implemented in the daily routine of investigators and in the policies of institutions, journals, and funding agencies.