Cause-Specific Mortality in Patients With Advanced Chronic Kidney Disease in the ISCHEMIA-CKD Trial

Systemic Inflammatory Response Index (SIRI) is associated with all-cause mortality and cardiovascular mortality in population with chronic kidney disease: evidence from NHANES (2001-2018)

Objective

To examine the correlation between SIRI and the probability of cardiovascular mortality as well as all-cause mortality in individuals with chronic kidney disease.

Methods

A cohort of 3,262 participants from the US National Health and Nutrition Examination Survey (NHANES) database were included in the study. We categorized participants into five groups based on the stage of chronic kidney disease. A weighted Cox regression model was applied to assess the relationship between SIRI and mortality. Subgroup analyses, Kaplan-Meier survival curves, and ROC curves were conducted. Additionally, restricted cubic spline analysis was employed to elucidate the detailed association between SIRI and hazard ratio (HR).

Results

This study included a cohort of 3,262 individuals, of whom 1,535 were male (weighted proportion: 42%), and 2,216 were aged 60 or above (weighted proportion: 59%). Following adjustments for covariates like age, sex, race, and education, elevated SIRI remained a significant independent risk factor for cardiovascular mortality (HR=2.50, 95%CI: 1.62-3.84, p<0.001) and all-cause mortality (HR=3.02, 95%CI: 2.03-4.51, p<0.001) in CKD patients. The restricted cubic spline analysis indicated a nonlinear relationship between SIRI and cardiovascular mortality, with SIRI>1.2 identified as an independent risk factor for cardiovascular mortality in CKD patients.

Conclusion

Heightened SIRI independently poses a risk for both all-cause and cardiovascular mortality in chronic kidney disease patients, with potentially heightened significance in the early stages (Stage I to Stage III) of chronic kidney disease.

The potential association between influenza vaccination and lower incidence of renal cell carcinoma

It is well-established that kidney cancer or renal cell carcinoma (RCC) occurs more commonly in chronic kidney disease (CKD) than in the general population, although the underlying mechanisms are incompletely understood. Beyond hereditary RCC syndromes; smoking, obesity and hypertension are widely known risk factors for RCC, irrespective of CKD. Kidney-specific factors such as episodes of acute kidney injury, nephrolithiasis and cyst formation have also been shown to be associated with RCC development. One potential and less explored factor is the role of viruses in the development of kidney cancer. In this issue of Clinical Kidney Journal, Lin et al. raise the interesting hypothesis that influenza vaccination may be associated with lower incidence of RCC in adults with CKD. We discuss potential mechanisms underlying this interesting observation in the context of immune dysregulation in CKD.

ISCHEMIA-EXTEND studies: Rationale and design

BACKGROUND

The ISCHEMIA and the ISCHEMIA-CKD trials found no statistical difference in the primary clinical endpoint between initial invasive management and initial conservative management of patients with chronic coronary disease and moderate to severe ischemia on stress testing without or with advanced chronic kidney disease (CKD). In ISCHEMIA, there was numerically lower cardiovascular mortality but higher non-cardiovascular mortality with no significant difference in all-cause death with an initial invasive strategy when compared with a conservative strategy. However, an invasive strategy increased peri-procedural myocardial infarction (MI) but decreased spontaneous MI with continued separation of curves over time, which potentially may lead to reduced risk of cardiovascular and all-cause mortality. Thus, the long-term effect of invasive management strategy on mortality remains unclear. In ISCHEMIA-CKD, the treatment and cause-specific mortality rates were similar during follow-up.

METHODS

Funded by the National Heart, Lung, and Blood Institute, the ISCHEMIA-EXTEND observational study is the long-term follow-up of surviving participants (projected median of 10 years) with chronic coronary disease from the ISCHEMIA trial. In the ISCHEMIA trial, 5,179 participants with moderate or severe stress-induced ischemia were randomized to initial invasive management with angiography, revascularization when feasible, and guideline-directed medical therapy (GDMT), or initial conservative management with GDMT alone and angiography reserved for failure of medical therapy. ISCHEMIA-CKD EXTEND is the long-term follow-up of surviving participants (projected median of 9 years) from the ISCHEMIA-CKD trial, a companion trial that included 777 patients with advanced CKD. Ascertainment of death will be conducted via direct participant contact, medical record review, and/or vital status registry search. The overarching objective of long-term follow-up is to assess whether there are between-group differences in long-term all-cause, cardiovascular, and non-cardiovascular mortality, and increase precision around the treatment effect estimates for risk of all-cause, cardiovascular, and non-cardiovascular mortality. We will conduct Bayesian survival modeling to take advantage of rich inferences using the posterior distribution of the treatment effect.

CONCLUSIONS

The long-term effect of an initial invasive versus conservative strategy on all-cause, cardiovascular, and non-cardiovascular mortality will be assessed. The findings of ISCHEMIA-EXTEND and ISCHEMIA-CKD EXTEND will inform patients, practitioners, practice guidelines, and health policy.