Customize your JAMA Network experience by selecting one or more topics from the list below.
Identify all potential conflicts of interest that might be relevant to your comment.
Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.
Err on the side of full disclosure.
If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.
Not all submitted comments are published. Please see our commenting policy for details.
Shpigel AA, Saeed MJ, Novak E, Alhamad T, Rich MW, Brown DL. Center-Related Variation in Cardiac Stress Testing in the 18 Months Prior to Renal Transplantation. JAMA Intern Med. 2019;179(8):1135–1136. doi:10.1001/jamainternmed.2019.0423
Approximately 40% of patients with end stage renal disease (ESRD) have ischemic heart disease.1 Given this high prevalence, many renal transplant centers assess patients for ischemic heart disease in the pretransplant evaluation. Once accepted as a transplant candidate and placed on the waiting list, there is little guidance regarding subsequent stress testing in asymptomatic individuals. We examined the predictors of and variation in stress testing in the 18 months prior to renal transplantation.
The Washington University Human Research Protection Office exempted this study from institutional review board oversight. From the United States Renal Data System,2 we identified patients with ESRD who underwent a first renal transplant between July 1, 2006, and November 30, 2013, were 40 years or older, and had primary Medicare insurance for at least 18 months prior to the transplant. Patient-level and facility-level characteristics were compared between patients who did and did not undergo stress testing using the t test and Pearson χ2 test for continuous and categorical variables, respectively. Nonnormal and ordinal variables were summarized by the median (first quartile, third quartile) and compared using the Mann-Whitney U test.
Variables with P < .10 on univariate analysis were entered into a multivariable logistic regression model that included both patient-level and center-level variables. A hierarchical model approach was used with the center as a second-level clustering variable. The median odds ratio (MOR) was determined to describe the likelihood of undergoing a stress test if a patient hypothetically moved from a center with a lower probability of having a stress test to one with a higher probability.3 All analyses were conducted in SAS version 9.3 (SAS Institute Inc), and P < .05 (2-sided) was considered significant. Data were analyzed from June 7, 2017, to February 1, 2019.
In 26 694 patients from 217 facilities, the percentage who underwent stress testing in the 18 months prior to renal transplantation by center ranged from 11.1% to 96.2% (median, 60.4%; interquartile range, 31.2%) (Figure). Individuals who underwent stress testing were older with higher percentages of white patients, female patients, recipients of kidneys from living donors, congestive heart failure, valvular disease, peripheral vascular disease, diabetes, hypertension, prior myocardial infarction, and coronary artery disease (Table).
Independent predictors of stress testing included white race (odds ratio [OR], 1.13; 95% CI, 1.05-1.21), diabetes (OR, 1.14; 95% CI, 1.05-1.24), hypertension (OR, 1.70; 95% CI, 1.55-1.86), coronary artery disease (OR, 2.66; 95% CI, 2.47-2.88), valvular disease (OR, 1.85; 95% CI, 1.66-2.07), peripheral vascular disease (OR, 1.11; 95% CI, 1.03-1.20), and cardiomyopathy (OR, 1.25; 95% CI 1.09-1.43). The MOR was 2.28 (95% CI, 2.04-2.48).
Our study demonstrates that substantial variability exists among centers in use of stress testing in the 18 months prior to renal transplant. With an MOR of 2.28, transplant center was second only to coronary artery disease in determining the use of stress testing,3 suggesting that the decision to perform a stress test was influenced more strongly by hospital culture than by all other individual patient characteristics, including those associated with coronary artery disease. Although it should be noted that while we accounted for a wide range of patient-level variables in performing our multivariable analysis, we cannot exclude the possibility that unmeasured confounders may have influenced the selection of patients for stress testing at each facility.
Variation in care is often attributed to differences in disease prevalence or access to care.4 However, neither of those factors is operative in this population of patients, all of whom had ESRD and were on the waiting list for renal transplantation. Rather, the variability in practice among centers suggests that there is no consensus regarding which patients, if any, should undergo stress testing. The lack of consensus may reflect the cognitive dissonance created by the strong association of ischemia on stress testing with adverse outcomes, the absence of data regarding the benefit of stress testing in patients with ESRD awaiting renal transplantation, and the presence of high-quality data that revascularization does not improve outcomes in other high-risk surgical populations.5 Defining the role of surveillance stress testing in patients awaiting renal transplantation requires randomized clinical trials.
Accepted for Publication: February 5, 2019.
Corresponding Author: David L. Brown, MD, Cardiovascular Division, Washington University School of Medicine in St Louis, 660 S Euclid Ave, Campus Box 8086, St Louis, MO 63110 (email@example.com).
Published Online: May 13, 2019. doi:10.1001/jamainternmed.2019.0423
Author Contributions: Mr Novak had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: Shpigel, Saeed, Alhamad, Rich, Brown.
Acquisition, analysis, or interpretation of data: Shpigel, Saeed, Novak, Rich.
Drafting of the manuscript: Shpigel, Saeed, Brown.
Critical revision of the manuscript for important intellectual content: Shpigel, Novak, Alhamad, Rich, Brown.
Statistical analysis: Shpigel, Saeed, Novak.
Obtained funding: Brown.
Administrative, technical, or material support: Brown.
Supervision: Alhamad, Rich, Brown.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by the Washington University Center for Administrative Data Research, which is supported in part by the Washington University Institute of Clinical and Translational Sciences grant No. UL1 TR002345 from the National Center for Advancing Translational Sciences of the National Institutes of Health and grant No. R24 HS19455 through the Agency for Healthcare Research and Quality.
Role of the Funder/Sponsor: The funder/sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Disclaimer: The data reported here have been supplied by the US Renal Data System. The interpretation and reporting of these data are the responsibility of the author(s) and in no way should be seen as an official policy or interpretation of the US government.
Create a personal account or sign in to: