Quantification of scientific output in cardiovascular medicine: a perspective based on global data.

AIMS: We sought to explore whether global and regional scientific output in cardiovascular medicine is associated with economic variables and follows the same trend as medicine and as science overall. METHODS AND RESULTS: We registered the number of documents, number of citations, citations per document and the h-index for the first 50 countries according to the h-index (a measure to evaluate both the productivity and impact of the publications) in cardiovascular medicine. Economic variables (gross domestic product [GDP] per capita, % expenditure of the GDP in research and development [R&D] and health) were obtained from the World Bank, the UNESCO, and the World Health Organization. In total, the scientific output in cardiology showed the same position as in medicine and science overall (mean difference vs. medicine -0.9±5.3º, p=0.25 vs. science -0.7±5.3º, p=0.39). We found significant correlations between the h-index and the % GDP expenditure in R&D (r=0.67, p<0.001), and the % GDP expenditure in health (r=0.71, p<0.0001). Overall, there was a 21.4% (interquartile range 3.7; 55.0) increase in the % GDP expenditure in R&D between 1996 and 2007. Emerging economies showed the larger growth in % GDP expenditure in health and R&D. CONCLUSIONS: The global situation of scientific output in cardiovascular medicine is highly polarised and closely related to economic indicators. Emergent economies, with higher rates of GDP growth and increasingly larger expenditures for R&D and healthcare, are expected to show a visible escalation in the scientific global picture in the near future.

Evaluation of Four-Year coronary artery response after sirolimus-eluting stent implantation using serial quantitative intravascular ultrasound and computer-assisted grayscale value analysis for plaque composition in event-free patients

This study sought to evalue the long term arterial response after sirolimus-eluting stent implantation. Sirolimus-eluting stents are effective in inhibbiting neointimal hyperplasia without affecting plaque volume behind the stent struts at six months. Serial quantitative intravascular ultrasound and computer-assisted grayscale value analysis over fours years were performed in 23 event-free patients treated with sirolimus-eluting stents. In the first two-years , the mean plaque volume ( 155,5 + - 42.8 mm3 post-procedure and 156.8 + - 57.7 mm3 at two years, p= 0.86) and plaque compositional chane expressed as mean percent hypoechogenic tissue of the plaque behind the stent struts...