Abnormalities in Cardiac Structure and Function among Individuals with CKD: The COMBINE Trial

Cardiac Magnetic Resonance Imaging Findings in Patients With Chronic Kidney Disease and End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

In this systematic review and meta-analysis, we explored the utilization of cardiac magnetic resonance imaging (CMR) to detect fibrotic changes secondary to uremic cardiomyopathy during the early stages of chronic kidney disease (CKD) and in patients with end-stage kidney disease (ESKD). Uremic myocardial fibrosis can lead to arrhythmia and heart failure, and it is important to detect these changes. CMR offers a noninvasive way to characterize the severity of cardiac remodeling. A comprehensive search of multiple electronic databases was conducted. Studies were divided according to scanner field strength (1.5 or 3 Tesla). The random effects model was used to calculate the pooled mean, 95% confidence interval (CI), standard error, and standardized mean difference (SMD). The I2 statistic was used to assess the heterogeneity between study-specific estimates. The search retrieved 779 studies. From these, 20 studies met the inclusion criteria and had 642 CKD patients (mean age of 56.8 years; 65.2% males; mean estimated glomerular filtration rate (eGFR) of 33 mL/min/1.73 m2) and 658 ESKD patients on dialysis (mean age of 55.6 years; 63.3% males; mean dialysis duration of 3.47 years). CKD patients had an increased left ventricular mass index (LVMi) compared to controls, with an SMD of 0.37 (95% CI: 0.20-0.54; I2 0%; p-value <0.05). ESKD patients also had increased LVMi compared to controls, SMD 0.88 (95% CI: 0.35-1.41; I2 79.1%; p-value 0.001). Myocardial fibrosis assessment using T1 mapping showed elevated values; the SMD of native septal T1 values between CKD and controls was 1.099 (95% CI: 0.73-1.46; I2 33.6%; p-value <0.05), and the SMD of native septal T1 values between ESKD patients and controls was 1.12 (95% CI: 0.85-1.38; I2 33.69%; p-value <0.05). In conclusion, patients with CKD and ESKD with preserved left ventricular ejection fraction (LVEF) have higher LVMi and T1 values, indicating increased mass and fibrosis. T1 mapping can be used for the early detection of cardiomyopathy and as a risk stratification tool. Large, randomized trials are needed to confirm these findings and determine the effect of long-term dialysis on cardiac fibrosis.

Associations of N-terminal pro-B-type natriuretic peptide, estimated glomerular filtration rate, and mortality in US adults

BACKGROUND

NT-proBNP is an important predictor of mortality but is inversely related to estimated glomerular filtration rate (eGFR). Whether the prognostic value of NT-proBNP is similar at different levels of kidney function is unknown.

AIMS

We evaluated the association of NT-proBNP with eGFR and its implications for all-cause and cardiovascular mortality risk in the general population.

METHODS

We included adults without prior cardiovascular disease from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2004. We used linear regression to characterize the cross-sectional associations of NT-proBNP with eGFR. We used Cox regression to assess the prospective associations of NT-proBNP with mortality across categories of eGFR.

RESULTS

Among 11,456 participants (mean age 43 years, 48% female, 71% White, 11% Black), there was an inverse association between NT-proBNP and eGFR, which was stronger in those with more impaired kidney function. Per 15-unit decrease in eGFR, NT-proBNP was 4.3-fold higher for eGFR<30; 1.7-fold higher for eGFR 30 to 60, 1.4-fold higher for eGFR 61 to 90, 1.1-fold higher for eGFR 91 to 120 mL/min/1.73 m2. Over a median 17.6 years of follow-up, 2,275 deaths (622 cardiovascular) occurred. Higher NT-proBNP was associated with higher all-cause (HR per doubling of NT-proBNP: 1.20, 95% CI: 1.16-1.25) and cardiovascular mortality (HR: 1.34, 95% CI 1.25-1.44). Associations were similar across eGFR categories (P-interaction >.10). Adults with NT-proBNP≥450 pg/mL and eGFR<60 mL/min/1.73m2 had 3.4-fold higher all-cause mortality and 5.5-fold higher cardiovascular mortality risk, compared to those with NT-proBNP<125 pg/mL and eGFR>90 mL/min/1.73m2.

CONCLUSION

Despite its strong inverse association with eGFR, NT-proBNP has robust associations with mortality across the full range of kidney function in the general US adult population.

Intestinal Lymphatic Dysfunction in Kidney Disease

Kidney disease is associated with adverse consequences in many organs beyond the kidney, including the heart, lungs, brain, and intestines. The kidney-intestinal cross talk involves intestinal epithelial damage, dysbiosis, and generation of uremic toxins. Recent studies reveal that kidney injury expands the intestinal lymphatics, increases lymphatic flow, and alters the composition of mesenteric lymph. The intestinal lymphatics, like blood vessels, are a route for transporting potentially harmful substances generated by the intestines. The lymphatic architecture and actions are uniquely suited to take up and transport large macromolecules, functions that differentiate them from blood vessels, allowing them to play a distinct role in a variety of physiological and pathological processes. Here, we focus on the mechanisms by which kidney diseases result in deleterious changes in intestinal lymphatics and consider a novel paradigm of a vicious cycle of detrimental organ cross talk. This concept involves kidney injury-induced modulation of intestinal lymphatics that promotes production and distribution of harmful factors, which in turn contributes to disease progression in distant organ systems.

Diversity, Equity, and Inclusion in Clinical Research: A Path Toward Precision Health for Everyone

Healthcare disparities are a persistent societal problem. One of the contributing factors to this status quo is the lack of diversity and representativeness of research efforts, which result in nongeneralizable evidence that, in turn, provides suboptimal means to enable the best possible outcomes at the individual level. There are several strategies that research teams can adopt to improve the diversity, equity, and inclusion (DEI) of their efforts; these strategies span the totality of the research path, from initial design to the shepherding of clinical data through a potential regulatory process. These strategies include more intentionality and DEI-based goal-setting, more diverse research and leadership teams, better community engagement to set study goals and approaches, better tailored outreach interventions, decentralization of study procedures and incorporation of innovative technology for more flexible data collection, and self-surveillance to identify and prevent biases. Within their remit of overlooking research efforts, regulatory authorities, as stakeholders, also have the potential for a positive effect on the DEI of emerging clinical evidence. All these are implementable tools and mechanisms that can make study participation more approachable to diverse communities, and ultimately generate evidence that is more generalizable and a conduit for better outcomes. The research community has an imperative to make DEI principles key foundational aspects in study conduct in order to pursue better personalized medicine for diverse patient populations.