Comprehensive NIH-Funding Analysis of Academic Cardiac Surgeons

Abstract

Objective:

National Institutes of Health (NIH) funding is becoming increasingly difficult to obtain. We sought to determine trends in NIH funding for cardiac surgeons hypothesizing they are at a disadvantage in obtaining funding due to intensive clinical demands.

Methods:

Cardiac surgeons (adult/congenital) currently at the top 141 NIH-funded institutions were identified using institutional websites. The NIH funding history for each cardiac surgeon was queried using NIH Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER). Total grant funding, publications, and type was collected. Academic rank, secondary degrees, and fellowship information was collected from faculty pages. Grant productivity was calculated using a validated Grant Impact Metric.

Results:

A total of 818 academic cardiac surgeons were identified, of which 144 surgeons obtained 293 NIH grants totaling $458 million and resulting in 6,694 publications. We identified strong associations between an institution’s overall NIH funding rank and the number of cardiac surgeons, NIH grants to cardiac surgeons, and amount of NIH funding to cardiac surgeons (all p<0.0001). The majority of NIH funding to cardiac surgeons is concentrated in the top quartile of institutions. Cardiac surgeons have high conversion rates from K-awards (mentored development award) to R01s (6/14; 42.9%). Finally, we demonstrate the rate of all NIH grants awarded to cardiac surgeons has increased, driven primarily by P and U (collaborative project) grants.

Conclusions:

NIH-funded cardiac surgical research has resulted in significant impact over the last three decades. Aspiring cardiac surgeon-scientists may be more successful at top quartile institutions due to infrastructure and mentorship.

INTRODUCTION

Obtaining National Institutes of Health (NIH) funding has become increasingly difficult for all scientists.¹ Furthermore, obtaining funding for clinically busy physician-scientists has become especially difficult.^1–3 Cardiac surgeons are amongst the busiest physicians clinically due to the unpredictable nature of their work, complexity and duration of operations, and high acuity of patients. Maintaining their surgical skills and learning new skills in an ever-changing field takes a tremendous amount of effort and time.

Meanwhile, impactful surgical research in the U.S. appears to be on the decline. In an analysis of the New England Journal of Medicine, the amount of research being published related to surgery has decreased substantially.⁴ Based on this evidence, evaluating the historical ability of cardiac surgeons to obtain NIH funding and their current status of NIH funding is crucial before the championed cardiac surgeon-scientist is extinct. In 2008, Ratcliffe and colleagues reported that cardiothoracic surgery faculty are applying for and receiving fewer NIH awards.⁵ Economic pressure from university systems, time pressure from increasing clinical productivity demands, and time away from research are cited as reasons for this disparity in cardiothoracic surgeons performing research.⁵ Despite these clinical demands, we hypothesized that cardiac surgeons are able to obtain NIH funding and perform either basic science or translational research. Second, we also hypothesized that cardiac surgeons are able to successfully use the training paradigm established by the National Institutes of Health: F32s (Individual Postdoctoral Fellowship), K-awards (Mentored Scientist Research Career Development Award), and R01s (Research Project Grant Program).

To this end, we have systematically evaluated active cardiac surgeons at the top 141 NIH-funded institutions in the United States (based on list published by the Blue Ridge Medical Institute).⁶ Specifically, we have analyzed individual surgeon NIH funding history and stratified them into congenital or adult cardiac surgeons. We believe that understanding the current state of NIH funding for cardiac surgeons across the country is a critical metric to determine how well cardiac surgeons are performing compared to their peers. We will also examine if extrinsic factors are leading to decreased research funding or whether major changes are needed within the field in order to preserve cardiac surgeon-scientists.

METHODS

Collection of Surgeon Data

An NIH rank list of funding was obtained from the Blue Ridge Medical Institute Table #2.⁶ Using this list, each academic institution was queried for its current attending cardiac surgeons. The oldest grant in our study was awarded in 1978. Care was taken to only include cardiac surgeons and to exclude strictly thoracic or vascular surgeons by including surgeons in cardiac sections and evaluating procedures performed or diseases treated by the surgeon. From these academic pages, the following data on each cardiac surgeon was collected: fellowships other than cardiac surgery, additional graduate degrees (other than MD or equivalent), current academic rank, and gender. Cardiac surgeons who are no longer in practice and not a part of the faculty were not included.

Collection of Grant Data

The National Institutes of Health Research Portfolio Online Reporting Tools Expenditures and Results (NIH RePORTER) was queried for each attending cardiac surgeon.⁷ All grants awarded to the cardiac surgeons were queried for the following using a Python script: principal investigator (PI), institution of work, project start date, project end date, total project funding, NIH institute, NIH study section, number of publications, and PMCID (Pubmed Central reference number) of each publication (used for calculation of grant impact metric). The types of grants were categorized according to the following: F32, K, R01, U (U01, U09, U10, U19), non-R01 R grants (R03, R18, R21, R29, R41, R42, R43, R56), T32s, and any other grants (Supplemental Table # 1). The categories were analyzed for the quantity of grants, total funding in that funding modality, number of papers resulting from that modality, Total Grant Impact, and Grant Impact Metric.

Calculation of Grant Impact Metric

We utilized the Journal of Citation Reports (2016) to determine the impact factor of the journal in which each manuscript from each grant was published.⁸ The total grant impact was determined by summing the impact factor of each manuscript resulting from a grant, and normalizing to the total funding of each grant (per $100,000). This Grant Impact Metric has been previously described, with the equation: “Grant Impact Metric = Σ (Impact Factor of each Paper) / Total Funding (per $100,000).^{1, 9, 10}

Statistics

Categorical variables are presented as count (percentage) while continuous variable as mean ± standard deviation depending on normality. All statistics were calculated using GraphPad Prism Version 8.0.1 (GraphPad Software, La Jolla California). Number of surgeons, grants, and total funding at each institution was analyzed and plotted according to the NIH rank of an institution as published by the Blue Ridge Medical Institute (NIH funded institutes were ranked from 1–141 based on amount of funding received in 2017). Linear regression analysis was utilized for association between rank of an institution and the number of surgeons, grants, and funding at that institution. A Chi-squared (χ²) test was used for categorical variables where appropriate. An alpha of 0.05 was used for statistical significance.

RESULTS

Demographic

Cardiac surgeons at the top 141 institutions funded by the National Institutes of Health (NIH) were analyzed for their NIH funding history. A total of 818 cardiac surgeons were discovered to be on faculty currently at these institutions from institutional faculty pages (Table 1). Of these, we discovered that 144 (17.6%) surgeons had obtained NIH funding at some point in their career while 674 (82.4%) surgeons had not obtained any NIH funding in their career. Four female cardiac surgeons have received NIH funding (4/51; 7.8% vs 140/767 male; 18.3%; p = 0.059). The NIH-funded cohort of surgeons also had a higher proportion of associate professors compared to the no-NIH funding group (24/140 vs. 56/674; p = 0.003). However, there were no differences between groups for graduate degrees or fellowships in addition to thoracic surgery. The cohort of cardiac surgeons was stratified by their practice as adult (237 grants; $372 million) or congenital cardiac surgeons (56 grants, $86.5 million) (Figure 1). Over the last 30 years, 144 NIH-funded cardiac surgeons have obtained approximately $460 million and published 6,694 manuscripts resulting from grant-related work.

Table 1:

Demographics of Cohort

	Funded (n =144)	No Funding (n = 674)	p-value
Male	140 (97.2%)	627 (93.0%)	0.059
Female	4 (2.8%)	47 (7.0)	0.059
Graduate Degrees (Other than MD)	24 (16.7%)	121 (18.0%)	0.714
PhD	19 (79.2%)	61 (50.4%)	0.123
MBA	1 (4.2%)	21 (17.4%)	0.103
Other	4 (16.7%)	39 (32.2%)	0.142
Congenital Fellowship	31 (21.5%)	165 (24.5%)	0.451
Other Fellowship	26 (18.1%)	156 (23.1%)	0.183
Assistant Professor	40 (27.8%)	233 (34.6%)	0.117
Associate Professor	24 (16.6%)	56 (8.2%)	0.003
Professor	42 (29.2%)	206 (30.6%)	0.741
Other/Unknown	38 (26.4%)	179 (26.6%)	0.967

Figure 1:

Consolidated Standards of Reporting Trials-style diagram of our cohort. There were 141 NIH-funded institutions and 818 cardiac surgeons who were analyzed in our study. Of these 818 cardiac surgeons, 144 have received NIH funding in their career (31 congenital cardiac surgeons and 113 adult cardiac surgeons). They have received over $468 million in funding. 674 surgeons have not received any NIH funding in their career.

Analysis of Surgeons According to NIH Rank of Institution

The number of funded and unfunded surgeons at each institution was analyzed according to the NIH ranking of the institutions. First, we analyzed the number of cardiac surgeons at each institution and the number of NIH-funded cardiac surgeons at those institutions. We found a strong association between NIH institution rank and the number of overall cardiac surgeons at an institution as well as the number of NIH-funded cardiac surgeons at the institution (Figure 2A; p < 0.0001). This trend was observed for both adult cardiac surgeons (Figure 2B; p < 0.0001) and congenital cardiac surgeons (Figure 2C; p < 0.0001). However, this was particularly notable for congenital surgeons, with over 83% of funded congenital cardiac surgeons working at the top quartile of NIH funded institutions..

Figure 2:

The number funded and unfunded all cardiac surgeons (2A), adult cardiac surgeons (2B), and congenital cardiac surgeons (2C) at the top 141-NIH funded institutions were quantified. There is a significant correlation between the number of all cardiac surgeons (2A), adult cardiac surgeons (2B), and congenital cardiac surgeons and the NIH funding of an institution (all p < 0.0001).

Grants Awarded to Current Cardiac Surgeons (1978 – 2018)

We analyzed the total number of grants awarded to all current cardiac surgeons over the last 40 years (Figure 3, Figure 4 and Table 2). A total of 293 NIH grants (238 to adult cardiac surgeons and 56 to congenital) were awarded to 144 cardiac surgeons. The majority of funding was for R01s (115 grants; $290.4 million; 2,815 papers; 4.4 average Grant Impact Metric).

Figure 3:

Breakdown of the grant types awarded to cardiac surgeons: F32, K-awards, R01s, U-awards, non-R01 R-awards, T32-awards, and others.

Figure 4:

The number of grants to all cardiac surgeons (4A), adult cardiac surgeons (4B), and congenital cardiac surgeons (4C) are all significantly associated to the NIH funding rank of an institution (p < 0.0001).

Table 2:

Grant breakdown of all NIH grants to cardiac surgeons

Grant	Number	Funding ($)	Papers	Total Grant Impact	Avg. Grant Impact Metric
F32	41	2,691,378	216	1245.63	50.05
K Awards	14	7,622,236	95	627.81	7.70
R01	113	288,010,456	2812	15969.21	4.47
U01, U09, U10, U19	18	50,939,407	400	2935.89	3.72
R03, R18, R21, R29, R41, R42, R43, R56	33	14,953,876	86	415.2	3.21
T32	4	11,153,703	380	1724.92	17.90
Other Grants	66	79,216,427	2696	17933.05	4.05

Avg.: Average

The number of grants awarded to cardiac surgeons strongly correlates with the NIH rank of the institution for all cardiac surgeons (Figure 4A; p < 0.0001), adult cardiac surgeons (Figure 4B; p < 0.0001), and congenital cardiac surgeons (Figure 4C; p < 0.0001). We found that 90% of congenital cardiac surgery grants are within the top quartile of NIH funded institutions..

Funding Summary

The funding history of active cardiac surgeons was analyzed. All the funding totals from each cardiac surgeon’s past NIH grants were summed according to each institution. These sums were then plotted according to the institution’s NIH ranking. Total funding, adult cardiac surgeon funding, and congenital cardiac surgeon funding were all significantly correlated to NIH funding rank of the institution (p < 0.0001; Figure 5 A, B, C). The top 3 institutions whose cardiac surgeons received the most NIH funding are: University of Pennsylvania, University of Maryland Baltimore, and Harvard Medical School. The top 3 institutions whose adult cardiac surgeons have received the most NIH funding are: University of Pennsylvania, University of Maryland Baltimore, and University of Virginia. The top 3 institutions whose congenital cardiac surgeons have received the most NIH funding are: Harvard Medical School, Icahn School of Medicine at Mount Sinai, and University of Pennsylvania. Congenital cardiac surgeons at only two institutions have received more than $10 million in funding: Icahn School of Medicine and Harvard Medical School.

Figure 5:

The amount of funding to each institution (according to NIH-funding rank) was analyzed for all surgeons (5A), $86.5 million in congenital cardiac surgeon funding (5B) and $382 million in adult cardiac surgery funding (5C). All funding correlates strongly to the NIH rank of the institution (p < 0.0001).

Temporal Analysis of Grants Awarded to Cardiac Surgeons

We analyzed the number of new grants and R01s (Figure 6A) awarded to cardiac surgeons and the number of active grants (Figure 6B) over the last 25 years (1992–2017; 2018 excluded due to year in progress). The number of new NIH grants that cardiac surgeons have received and active grants they have maintained has increased steadily over time (p = 0.008 and p < 0.0001). The number of new R01s that cardiac surgeons have received has not increased over time (p > 0.05), whereas the number of active R01s has significantly increased over the last 25 years (p < 0.0001) and plateaued at approximately 30 grants from 2000 onwards. This suggests that cardiac surgeons have improved in their ability to receive non-R01 grants, while the rate of R01s awarded to cardiac surgeons has been stable. The complete list of currently active grants is shown in Supplemental Table # 2.

Figure 6:

The number of new NIH grants (not renewals) awarded to cardiac surgeons each year is shown (p = 0.008). The number of new R01s (not renewals) awarded to cardiac surgeons each year is shown (p = 0.118).

Mentored Awards (F32, K) to R01 Funding

We evaluated the number of F32-awards, K-awards (K04, K08, K23), and number of investigators with R01s (Figure 7). We also analyzed the number of investigators who transitioned from an F32 to a K-award, an F32 to an R01, or from a K-award to an R01. Forty-one investigators received F32-awards during their residency (33 adult, 8 congenital), 14 received K-awards (10 adult, 4 congenital), and 62 investigators have received R01s (51 adult, 11 congenital). Nine investigators (9/41; 22%) transitioned from F32-awards to an R01, 3 investigators (3/41; 7.3%) transitioned from an F32-award to a K-award, 6 investigators (6/14; 42.9%) transitioned from a K-award to an R01, and one investigator progressed through all three funding modalities.

Figure 7:

The number of investigators with F32-awards (n = 42), K-awards, (n = 14) and R01 awards (n = 62) were analyzed. We also analyzed the number of surgeons who transitioned from an F32 postdoctoral award to a junior faculty mentored K-award (n = 3), from an F32-award directly to an R01 (n = 9), from a K-award to an R01 (n = 6), and the number of surgeons who went through all three funding modalities (n = 1).

DISCUSSION

This study has determined the NIH funding record for all current academic cardiac surgeons at the top 141 NIH-ranked institutions.⁶ Of 818 active surgeons, 144 cardiac surgeons have been awarded 293 NIH grants, obtained $458 million in funding, and published 6,694 papers as a result of these grants over a 30 year period. We evaluated the number of cardiac surgeons (113 adult and 31 congenital), number of NIH grants to cardiac surgeons (293 total), and amount of funding to cardiac surgeons at each NIH-funded institution ($458.0 million total). Further, we analyzed the number of cardiac surgeons who followed the traditional NIH training paradigm of F32-award → K-award → R01 award (3/41 F32 to K, 9/41 F32 to R01, 6/14 K to R01, and 1/41 F32 to K to R01). Finally, we evaluated the number of grants awarded to currently active cardiac surgeons over the last 30 years and found that the overall number of NIH grants received per year is increasing, however the rate of cardiac surgeons obtaining R01s has not increased.

While evaluating the demographics of our population of surgeons (Table 1), we found that only 4 practicing female cardiac surgeons (7.8% of all female cardiac surgeons; 1 congenital and 3 adult cardiac) have received NIH funding in their career. This represents 2.8% (4/144) of all NIH-funded cardiac surgeons. We expected the percentage of funded female cardiac surgeons (4/51; 7.8%) to be similar to the percentage of funded male cardiac surgeons (140/767; 18.3%). However, there was a trend towards a higher proportion of male surgeons having had NIH funding compared to female surgeons (p = 0.059). One possibility for this low percentage of female cardiac surgeons obtaining NIH funding is that only about 20% of female cardiothoracic surgeons have reported having protected time for research in a survey of female cardiothoracic surgeons.¹¹ According to an editorial by Kron, “protected time and institutional support” are crucial to being competitive for NIH funding.¹² Increasing protected research time for all cardiac surgeons may be one way to increase the funding rates. We also discovered that the professorship level between the two groups was significantly different when evaluating the percentage of associate professors (n = 24 [16.6%] for NIH-funded vs. 56 [8.2%] for the no NIH funding group; p = 0.003). We hypothesize that obtaining extramural research funding plays a critical component in the promotion and tenure process and aids in being promoted.¹³ Faculty in our NIH-funded cohort may be able to achieve promotion to the associate professor position quicker compared to their unfunded cohort due to a boost in their portfolio from the extramural funding.

When analyzing all NIH grants to cardiac surgeons and not only R01s, we find that cardiac surgeons have continued to receive NIH grants at an increasing rate over the last 25 years (Figure 6A). We also find that the number of active grants has increased whereas the number of active R01 grants has plateaued (Figure 6B). This suggests that while cardiac surgeons are not receiving more NIH grants for individual research project grants (R01s), they are receiving other types of grants. These grants (U grants, Program Project Grants, F32-awards, K-awards, and M01) tend to be more collaborative and involve large research teams or mentors rather than one individual principal investigator leading a research project. Further, the subject matter of the grants has included basic science research in all years examined (1978–2018), however, the number of collaborative outcomes grants and the number of product development/clinical trial grants have increased within the last 20 years. To combat increasing clinical pressures, increasing demand of publishing papers with complex small animal models and larger projects, and difficulty in obtaining R01 funding, cardiac surgeons may be opting for a team-based approach to performing science.¹⁴ In our analysis of grant breakdown, the largest group of grants was R01s (n = 117, $300 million; Table 2). The average Grant Impact Metric (4.4) for these R01 grants is very similar to the Grant Impact Metric of all other surgery specialty R01s (4.9) and slightly higher than general surgery R01s (3.73).¹ When we analyze the number of new R01 grants awarded by the NIH to cardiac surgeons, we find that cardiac surgeons have not been getting more R01s despite increases in NIH funding over the last 25 years (Figure 6).¹

Analysis of cardiac surgery grants and cardiac surgeons according to the NIH rank of the institution revealed a significant correlation between NIH funding rank of an institution and the size of their cardiac surgery group (Figure 2), number of NIH grants received throughout the careers of current cardiac surgeons (Figure 4), and the amount of funding to these cardiac surgeons (Figure 5). The majority of cardiac surgery research happens at the top 25% of NIH-funded institutions. This may be due to the majority of cardiac surgeons being a part of the faculty at these institutions. Over 90% of congenital cardiac surgeon grants have been in the top quartile of NIH-funded institutions. While larger academic centers are expected to have higher cardiac surgery volume, young surgeons who are planning to perform research may seek out positions at these top 25% NIH-ranked institutions where they can have experienced mentors. Learning from experienced, NIH-funded surgeon-scientists at these institutions should be a priority for surgical residents, fellows, and junior faculty who aim to become “triple threats” (teaching, researching, and operating).

Finally, in our analysis of mentored research awards (K-awards), we discovered that the rate of transition from a K-award to an R01 (6/14; 42.9%) for cardiac surgeons is equivalent to the 10-year transition rate of 42.5% for all physicians receiving a K08 or K23 award as reported by Jagsi et al (42.5% of 2783 K-awardees) for all specialties.¹⁵ This finding is also not significantly different from our previous work analyzing the K-award to R01 conversion rate for the combined cohort of thoracic, cardiac, and vascular surgeons (20/38; 52.6%; p = 0.53).⁹ All of the 14 K-award recipients are in the top 1/3 of institutions when ranked by amount of funding to cardiac surgeons. Surgeons who are successful at obtaining K-awards are at institutions where infrastructure, departmental support, and mentorship for research are strong.

Our study was limited by a few factors. We only evaluated NIH funding to academic cardiac surgeons and did not evaluate other sources of funding such as private companies, foundations, or societal grants therefore the percentage of academic surgeons receiving grants may be inflated. Only surgeons listed on faculty lists at institutions were evaluated for our study and the accuracy of the faculty pages could not be accounted for. Tenure status of the investigator was not queried due to lack of this information on faculty pages. Only current academic surgeons were included. Surgeons who were at an academic institution and then moved to a private practice or are now retired were not captured. We were also not able to find any obvious extrinsic factors that accounted for funding differences between surgeons or institutions. Finally, we were only able to evaluate data that was available in NIH RePORTER such as manuscripts listed as resulting from a particular grant and funding amounts.

We have systematically characterized the NIH funding status and history for all current academic cardiac surgeons in the United States. Cardiac surgeons perform equally well compared to surgeons in other disciplines with respect to Grant Impact Metric. Additionally, cardiac surgeons are efficient at converting K-awards into R01 funding. Finally, cardiac surgeons are effective surgeon-scientists despite difficulties in obtaining NIH funding, increasing clinical demands, and they should continue to be funded by the NIH.

Perspective Statement.

NIH funding is crucial for cardiac surgeons who want to perform clinical and translational research. In our manuscript we have systematically analyzed the NIH funding history of all current academic cardiac surgeons. Our findings have identified institutions for aspiring cardiac surgeon-scientists to find research expertise, mentorship, and infrastructure.

Central Message.

NIH funding is becoming increasingly difficult to obtain, especially for busy clinical specialties such as cardiac surgery. We have shown that cardiac surgeon-scientists excel at obtaining NIH grants.

Central Picture Legend.

25-year history of cardiac surgeons obtaining National Institutes of Health Grants.

Abbreviations

NIH

National Institutes of Health

RePORTER

Research Portfolio Online Reporting Tools Expenditures and Results