Author + information
- Sadeer G. Al-Kindi, MD and
- Guilherme H. Oliveira, MD∗ ()
- ↵∗Section of Heart Failure, Harrington Heart and Vascular Institute, University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, Ohio 44106
We read with interest the paper by Hanberg et al. (1). In their analysis of the ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) trial, they showed that there was a lack of association between estimated glomerular filtration rate (eGFR) and cardiac index (CI) in 575 patients with heart failure. Given the small sample size and concern for type II error, we tried to replicate their analyses in a larger, much sicker heart failure population.
Using the United Network for Organ Sharing registry, we estimated kidney function by using GFR (2) and CI (using Mosteller’s body surface area estimation ) for all adults listed for heart transplantation (2008 to 2015). We excluded patients who were undergoing dialysis at the time of listing. Pearson’s correlations and ANOVA tests were performed to identify statistical differences in the overall population and in subgroups. Paired Student t test was performed to assess differences in eGFR at listing and prior to transplantation.
A total of 22,052 patients were included in this analysis. There was no correlation between eGFR and CI (Pearson’s r = 0.013; p = 0.056). Additionally, there were no differences in eGFR by CI group (ANOVA p = 0.329) (Figure 1). Among 4,806 patients who had a left ventricular assist device at listing, eGFR did not correlate with CI (r = 0.011; p = 0.448), and there were no differences in eGFR among CI groups (p = 0.142). When stratified by hemodynamic profile (pulmonary capillary wedge pressure greater or less than 18 mm Hg and CI less than or greater than 2.2 l/min/m2), there was a small, but statistically significant correlation between eGFR and CI: cold and wet (r = −0.027; p = 0.02), cold and dry (r = 0.033; p=0.039), warm and dry (r = 0.04; p=0.008), but not warm and wet (r = −0.023; p=0.171).
Additionally, among patients who underwent transplantation (median time to transplantation: 88 days), paired eGFR (at listing and prior to transplantation) were available for 14,636 patients. Overall, there were no statistical differences in eGFR between listing and transplantation (at listing = 70.9 ± 26.5 ml/min per 1.73 m2 vs. pre-transplant = 70.6 ± 27.1 ml/min per 1.73 m2; p = 0.082). There was a very small inverse relationship between baseline CI and change in GFR (r = −0.036; p<0.001).
Thus, our data confirm results of the study by Hanberg et al. (1) in a much larger, more contemporary, sicker population of heart failure patients. Further studies are needed to examine the complex heart-kidney conundrum.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation