Angiogenesis Research

Grants, Funding Mechanisms, and Publication Output for the NHLBI-Funded Angiogenesis Research

We identified a cumulative total of 1901 angiogenesis grants from fiscal years 2008 through 2015. About 94% (1788 awards) represent investigator-initiated research, and 6% (113 awards) is NHLBI-solicited research. Examples of Requests for Applications were The Cardiovascular Cell Therapy Research Network (HL12-026) and New Strategies for Growing 3D Tissues (HL11-025). The temporal trends of awards and awarded dollars during this period are presented in Figure A. Yearly, an average of 229±26 grants were awarded, and the average overall funding, including direct and indirect costs, was $116±20 million. The total yearly cost per award was ≈$485±25 thousand. Additional awards were made under the American Recovery and Reinvestment Act stimulus program: 47 ($14 million) in fiscal year 2009 and 25 ($13 million) in fiscal year 2010. The decline of funding in recent years does not seem specific to angiogenesis research but rather consistent with trends in total NHLBI grants funding during the same period (Online Figure II).

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Figure.

The National Heart, Lung, and Blood Institute (NHLBI)–funded angiogenesis research from fiscal years (FYs) 2008 through 2015. A, Annual awards and awarded dollars. Dark bars represent the total annual number of awards. The line represents the annual awarded dollars. Dollars listed are the yearly total costs (direct plus indirect costs). Light bars indicate the number of additional awards made under the American Recovery and Reinvestment Act (ARRA) during 2009 and 2010. B, Publications and estimated cost per publication. Dark bars represent the total annual number of awards. Light bars indicate the total yearly number of publications citing NHLBI angiogenesis grant support. The line depicts the dollars per publication per year (total funding divided by total number of publications per FY). C, Major funding mechanisms of angiogenesis research. Stacked color bars represent the distribution of total number of awards per year per mechanism. Colored lines depict the total awarded dollars in each FY for each funding mechanism: R01, P01, U01, and R21+R4* (R43 and R44). R01, Research Project Grant; P01, Research Program Project Grant; U01, Research Project Cooperative Agreement; R21, Exploratory/Developmental Research Grant; R43 and R44, Small Business Innovation Research and Small Business Technology Transfer grants, respectively. Other less-used mechanisms were not included in this figure.

Using each unique grant number, we identified a total of 6009 publications on PubMed, including 915 (15%) review articles, acknowledging NHLBI-funding support, as required by the NIH Public Access Policy (http://publicaccess.nih.gov/). On average, each grant generated 3.3±0.3 publications per year (Online Figure III). American Recovery and Reinvestment Act funding for 2009 and 2010 produced a total of 176 publications (included in the figure). The average cost per publication (calculated as yearly total awarded dollars divided by yearly total associated publications) was $154±24 thousand (Figure B), consistent with other NHLBI-supported research areas and within the national estimates of cost per publication for academic-based research.³

The NHLBI angiogenesis portfolio was funded through 4 major funding mechanisms (http://grants.nih.gov/grants/funding). The predominant types of awards across all years were Research Project Grants, or R01s (64%); followed by Research Program Project Grants or P01s (9%); Exploratory/Developmental Research Grants or R21s, Small Business Innovation Research or R43s and Small Business Technology Transfers or R44s (5%); and Research Project Cooperative Agreements or U01s (1%) as shown in Figure C. Across all years, 52% of funds were allocated for R01s; 33% for P01s; 3% in aggregate for R21s, R43s, and R44s; and 1% for U01s. Each subproject and core of P01s were counted as an individual award in these analyses. Since 2011, NHLBI has not supported the unsolicited R21 mechanism. Less-used funding mechanisms were not tabulated in this figure. Most funding was awarded for noncompeting continuation of research (type 5 grants). An average of 19±3% of awards was issued yearly to new research (type 1 grants), which may represent pursuit of new directions in angiogenesis research (Online Figure IV).

Trends of Scientific Areas and Topics for the NHLBI-Funded Angiogenesis Research

The NIH and NHLBI have a long history of supporting a diverse portfolio of basic, translational, and clinical research.⁴ NIH views basic scientific discovery as the engine that powers the biomedical enterprise and continues to spend more than half of its budget supporting basic research.⁵ Using grant codes, we categorized NHLBI-funded angiogenesis research as basic if using in vitro methods only (9.7% of awards, 5% of total dollars) or as translational if using in vivo animal models (74.1% of awards, 65% of total dollars) or human subject studies, excluding clinical trials (13.7% of awards, 27% of total dollars). The remainder of this portfolio is represented by clinical trials (2.5% of awards, 3% of total dollars).

Through a key term search of the title, abstract, and specific aims of each grant, we did a nonexhaustive analysis of the types of mechanism of angiogenesis. Of the total 1901 grants, 1616 grants cited angiogenesis, 270 grants cited vasculogenesis, 234 grants cited sprouting angiogenesis, 220 grants cited arteriogenesis/collaterals/collaterogenesis, and 15 grants cited intussusceptive or splitting angiogenesis (Table). There is overlap because some grants included references to >1 angiogenesis mechanism.