Risks of Adverse Events in Advanced CKD: The Chronic Renal Insufficiency Cohort (CRIC) Study

Abstract

Background: People with advanced chronic kidney disease are at risk for the development of end-stage renal disease (ESRD), but also many other adverse outcomes, including cardiovascular disease (CVD) events and death. Determination of risk factors that explain the variability in prognosis and timing of these adverse outcomes can aid patient counseling and medical decision making.

Study design: Prospective research cohort.

Setting & participants: 1,798 participants with estimated glomerular filtration rates (eGFRs)<30mL/min/1.73m² in the CRIC Study were followed up for a median of 5.5 years.

Predictors: Age, race, sex, eGFR, proteinuria, diabetes mellitus, body mass index, ejection fraction, systolic blood pressure, history of CVD, and smoking history.

Outcomes: ESRD, CVD (congestive heart failure, stroke, myocardial infarction, and peripheral artery disease), and death.

Results: Baseline age of the cohort was 60 years, 46% were women, and 46% were African American. Although 52.3% of participants progressed to ESRD during follow-up, the path by which this occurred was variable. For example, predicted 1-year probabilities for a hypothetical 60-year-old white woman with eGFR of 30mL/min/1.73m², urine protein excretion of 1.8g/d, and no diabetes or CVD (risk characteristics similar to the average participant) were 3.3%, 4.1%, and 0.3%, for first developing CVD, ESRD, and death, respectively. For a 40-year-old African American man with similar characteristics but higher systolic blood pressure, the corresponding 1-year probabilities were 2.4%, 13.2%, and 0.1%. For all participants, the development of ESRD or CVD increased the risk for subsequent mortality, with no differences by patient race or body mass index.

Limitations: The CRIC population was specifically recruited for kidney disease, and the vast majority had seen a nephrologist.

Conclusions: The prognosis and timing of adverse outcomes in chronic kidney disease vary by patient characteristics. These results may help guide the development of personalized approaches for managing patients with advanced CKD.

Keywords: CKD progression; CRIC (Chronic Renal Insufficiency Cohort); Chronic kidney disease (CKD); advanced CKD; adverse event; cardiovascular disease (CVD); disease trajectory; end-stage renal disease (ESRD); incident ESRD; kidney function decline; mortality; pre-ESRD death; prognosis; risk factor.

Figure 1

Cumulative incidence of first events (ESRD, CVD, or death) over time among CRIC study participants from eGFR 30 ml/min/1.73 m² (N=1798).

Figure 2

Cumulative incidence of subsequent events (ESRD, CVD, or death) over time among CRIC study participants. (A) reflects the incidence of ESRD and pre-ESRD death after the occurrence of a first CVD event (N=455); (B) reflects the occurrence of CVD or pre-CVD death after a first ESRD event (N=678); and (C) reflects the incidence of death after the occurrence of ESRD then CVD or CVD then ESRD, with time at risk accruing after the latter event (N=248).

Figure 2

Cumulative incidence of subsequent events (ESRD, CVD, or death) over time among CRIC study participants. (A) reflects the incidence of ESRD and pre-ESRD death after the occurrence of a first CVD event (N=455); (B) reflects the occurrence of CVD or pre-CVD death after a first ESRD event (N=678); and (C) reflects the incidence of death after the occurrence of ESRD then CVD or CVD then ESRD, with time at risk accruing after the latter event (N=248).

Figure 2

Cumulative incidence of subsequent events (ESRD, CVD, or death) over time among CRIC study participants. (A) reflects the incidence of ESRD and pre-ESRD death after the occurrence of a first CVD event (N=455); (B) reflects the occurrence of CVD or pre-CVD death after a first ESRD event (N=678); and (C) reflects the incidence of death after the occurrence of ESRD then CVD or CVD then ESRD, with time at risk accruing after the latter event (N=248).