What's catching our readers' eye? Analysis of downloads of Cardiovascular Research articles

Cardiovascular Research accepts submissions of original papers from the entire realm of cardiac and vascular basic science. And indeed, the submissions show a large diversity of topics. The elaborate review process involving experts in the various specific fields of research is the deciding factor that determines the selection of papers finally published. It is generally assumed that in the long run the accumulating citations of a published paper in other qualified scientific journals can be taken as a sign of its lasting scientific value. Citations do not, however, reflect the immediate awareness, i.e. the ‘news value’ of the topic of a given article. In times of electronic journal usage, this immediate interest ignited by a given publication in the scientific community can be estimated from its early electronic usage by tallying the number of times an article is downloaded online. The editors of Cardiovascular Research use the download information regularly to follow quick trends of interest in their readership. Here we report on the 10 most-downloaded original articles from January 2009 to July 2010. We counted the downloads of full-length articles for a window that included the electronic in-press period and the 2 months following appearance in print for each paper. The newest articles we evaluated are from July 2010. With the same method, we also evaluated the downloads of review papers during this period. Clearly, the download statistics of reviews does not reflect public awareness in the same way as original articles, as Cardiovascular Research publishes most of its reviews in groups with pre-determined general themes (e.g. in Spotlight issues). Nevertheless, it is of interest to see which of the review articles get the most rapid attention of our readership. By and large, the most-downloaded original articles can be grouped into three main categories: (i) new strategies for cardiac protection on the road from ischaemia–reperfusion to heart failure (original articles 1, 3, 9, 10 in Table 1); (ii) new concepts for stem cell replacement of lost cells in cardiac or vascular tissues (original articles 2, 6, 7); (iii) new recipes for vascular protection and repair (original articles 4, 5, 8). In general, this reflects a current trend in basic cardiovascular science focusing on cardiovascular protection and tissue repair. Most downloaded articles published in the period January 2009–July 2010 aTotal downloads of full-length text from in-press period and first two months after publication. Most downloaded articles published in the period January 2009–July 2010 aTotal downloads of full-length text from in-press period and first two months after publication. In cardiac medicine, the highest priority for therapeutics is the protection of cardiac cells that would otherwise deteriorate in the setting of ischaemia–reperfusion and the subsequent development of heart failure. This priority is mainly based on the fact that ischaemic cardiac diseases and heart failure are of predominant importance in clinical cardiology and in medicine in general. Ischaemic heart disease is the leading cause of mortality in the world population and is predicted to remain in first place until at least 2030.1 In the acute phase of ischaemia and reperfusion, necrotic cardiac cell death prevails, but in the process of changes leading to heart failure, programmed cell death also seems to play a major role. Causes and mechanisms of this form of cardiac cell death are still a matter of intense debate. This may well explain the attention given two original articles (original articles 3 and 9) that investigate the roles of autophagy and apoptosis. Other mysteries on the road from ischaemia–reperfusion to heart failure may have stimulated the many downloads of several of our reviews addressing aspects of myocardial remodelling and ensuing failure (reviews 1, 2, 4, 9, 10). Several of the most-downloaded review papers analyze the various mechanisms of cell death (reviews 4 and 5), the role of inflammation and the effect of inflammatory mediators on cellular metabolism (original article 10, review 10) and on scar formation (original article 1, review 10) that can all contribute to unfavourable cardiac remodelling. The most downloaded article (original article 1), which also deals with the area of cardioprotection, describes microRNA expression after myocardial infarction. MicroRNA research has developed in an explosive way in the cardiovascular field, exemplifying the rapidity of changes in scientific paradigms in this area. Our journal identified the interest in microRNA research in the cardiovascular field very early and published a review focus issue on this topic in September 2008 (see Condorelli and Dimmeler2 and other articles in that issue). Hopes are great that cell replacement strategies using stem cells from external or internal sources will be able to heal damaged myocardium and vessels. It is also clear by now that tissue repair by cell therapy is everything but an easy task. In spite of the many biologically seemingly feasible approaches to cardiovascular cell therapy, the clinically relevant break-through is still not in sight. In this situation, news from basic science on approaches that are off the beaten path attracts attention. Among our most-downloaded papers was a report on forced ‘forward programming’ of pluripotent stem cells towards a cardiac phenotype (original article 2) and the use of fat cells to generate heart cells in vitro (original article 6). The design of a new approach to generate artificial tissue through the use of stem cells also generated immediate interest (original article 7); here, one may speculate that this is because there is growing hope that the rapid cell loss from cell infusions into the myocardium might be overcome by applying patches of pre-fabricated artificial tissue to the injured heart. In the vascular field, surprisingly, an article with an essentially negative finding gained considerable attention (original article 4). It reported that in a model of chronic vascular dysfunction, bone marrow-derived endothelial progenitor cells unfortunately do not repair endothelium. That a negative study received such attention is interesting and might be attributed to a general movement of the expectations of immediate cardiovascular applications of cell therapy towards a more realistic position after an initial period of unjustified—but understandable—optimism. The good news in another paper, on the other hand, was that activation of the deacetylase sirtuin 1 can stimulate a vasoprotective endothethial phenotype and this can be achieved by the natural polyphenol resveratrol (original article 5). Ischaemic angiogenesis is a potential means of tissue repair; this made a report on a novel chemokine antagonist that stimulates angiogenesis in an ischaemia model very attractive to our readers (original article 8). Cardiovascular Research also published several review articles on vascular issues during the period analysed here, of which several gained immediate attention (reviews 3, 6, 7, 8). These reviewed vascular signalling related to atherosclerosis and vascular dysfunction from new angles, e.g.by investigating the antagonistic roles of vascular oxygen radicals as chemical toxins and signalling molecules (reviews 3, 7), matrix metalloproteinases as endogenous signalling molecules (review 6), or the many faces of PI 3-kinase isoforms (review 8). In summary, analysis of what catches the eye of Cardiovascular Research readers through analysis of downloads provides a snapshot of the hot spots of the present scientific discussion within the cardiovascular community and helps our journal to be one of the best-cited in its field.