Plasma proenkephalin A and incident chronic kidney disease and albuminuria in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort.

BACKGROUND: Plasma proenkephalin A (PENK-A) is a precursor of active enkephalins. Higher blood concentrations have been associated with estimated glomerular filtration rate (eGFR) decline in European populations. Due to the significant disparity in incident chronic kidney disease (CKD) between White and Black people, we evaluated the association of PENK-A with incident CKD and other kidney outcomes among a biracial cohort in the U.S. METHODS: In a nested cohort of 4,400 participants among the REasons for Geographic And Racial Differences in Stroke, we determined the association between baseline PENK-A concentration and incident CKD using the creatinine-cystatin C CKD-EPI 2021 equation without race coefficient, significant eGFR decline, and incident albuminuria between baseline and a follow-up visit 9.4 years later. We tested for race and sex interactions. We used inverse probability sampling weights to account for the sampling design. RESULTS: At baseline, mean (SD) age was 64 (8) years, 49% were women, and 52% were Black participants. 8.5% developed CKD, 21% experienced ≥ 30% decline in eGFR and 18% developed albuminuria. There was no association between PENK-A and incident CKD and no difference by race or sex. However, higher PENK-A was associated with increased odds of progressive eGFR decline (OR: 1.12; 95% CI 1.00, 1.25). Higher PENK-A concentration was strongly associated with incident albuminuria among patients without diabetes mellitus (OR: 1.29; 95% CI 1.09, 1.53). CONCLUSION: While PENK-A was not associated with incident CKD, its associations with progression of CKD and incident albuminuria, among patients without diabetes, suggest that it might be a useful tool in the evaluation of kidney disease among White and Black patients.

Markers of Kidney Tubule Dysfunction and Major Adverse Kidney Events.

BACKGROUND: Serum creatinine and albuminuria are primary markers of glomerular function and injury, respectively. Tubular secretion, acid-base homeostasis, protein reabsorption, among other tubular functions, are largely ignored. This mini-review aimed to discuss how two tubular functions, secretion, and acid-base homeostasis are associated with major adverse kidney events (MAKEs). SUMMARY: Proximal tubular secretion is an essential function that allows the elimination of endogenous substances and drugs. Recently discovered endogenous markers in urine and plasma allow a noninvasive way of assessing tubular secretion markers. Several studies have found an association between these markers and a higher risk of chronic kidney disease (CKD) progression and mortality. In a study we recently performed among patients with CKD and at risk of cardiovascular events, lower tubular secretion was associated with an increased risk of acute kidney injury and metabolic acidosis, independent of baseline eGFR and albuminuria. The kidney tubules also play a crucial role in acid-base homeostasis. Although the standard clinical assessment of acidosis consists of measuring serum bicarbonate, urinary ammonium excretion decreases before over metabolic acidosis. Urinary ammonium excretion is associated with CKD progression, a higher risk of kidney failure, and an increased mortality risk, independent of baseline eGFR and albuminuria. KEY MESSAGES: Novel biomarkers of kidney tubular health consistently associate with MAKEs, above and beyond baseline eGFR, albuminuria, and other CKD risk factors. Tubular markers may provide new opportunities to improve kidney prognosis, drug dosing, and monitoring for adverse events.

Resource Utilization During Elective Robotic-Assisted Percutaneous Coronary Intervention.

OBJECTIVE: Robotic percutaneous coronary intervention (R-PCI) results in comparable outcomes to manual PCI in the treatment of obstructive coronary artery disease (CAD). The objective of this study is to evaluate the cost and resource utilization of R-PCI compared with manual PCI. METHODS: Consecutive patients with CAD undergoing elective R-PCI or manual PCI over an 18-month period by a single operator were included. Procedure-related costs and resource utilization were analyzed and propensity adjusted to account for differences in baseline demographic and lesion characteristics. RESULTS: A total of 164 patients (mean age, 68.9 ± 10.8 years; 81% men) underwent R-PCI (n = 56) or manual PCI (n = 108). The R-PCI group demonstrated higher Syntax scores (17.8 ± 12.9% vs 11.8 ± 7.7%; P<.01) and a greater proportion of type B2/C lesions (89.3% vs 69.4%; P<.01). R-PCI was associated with higher unadjusted costs of total hospitalization ($8219.90 ± 336.60 vs $7268.50 ± 220.10; P=.02) and direct supplies ($4711.10 ± 239.90 vs $3809.40 ± 166.80; P<.01). Following propensity-matched analysis, R-PCI was associated with higher direct supply costs alone, without a significant difference in total hospitalization or catheterization laboratory cost. Furthermore, R-PCI demonstrated similar fluoroscopy time, procedural time, and total number of stents, but with a lower volume of contrast (182.7 ± 8.9 mL vs 206.8 ± 9.0 mL; P=.04). CONCLUSIONS: Costs and resources associated with R-PCI are comparable with manual PCI, with an expected increase in direct supply costs attributed to single-use robotic components.