MO195: Kidney Function and the Risk of Heart Failure Among Older Adults: A Prospective Population-Based Cohort Study
Authors: Douros Antonios , Schneider Alice , Ebert Natalie , Huscher Dörte , Kuhlmann Martin K , Martus Peter , Mielke Nina , Van der Giet Markus , Wenning Volker , Schaeffner Elke 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Decreased kidney function is an established risk factor of cardiovascular morbidity including heart failure (HF) as well as cardiovascular and all-cause mortality among adults. However, the role of decreased kidney function with regard to these outcomes among old and very old adults remains poorly understood. This is an important knowledge gap given the common decline of kidney function in advanced age, which can affect both healthy individuals and patients with significant morbidity. To this end, we conducted a population-based study to assess whether decreased kidney function is associated with an increased risk of HF, cardiovascular and all-cause mortality in a prospective cohort of community-dwelling older adults.

METHOD
We included participants of the Berlin Initiative Study (BIS), age ≥70 years, with estimated glomerular filtration rate (eGFRBIS2) at baseline (between 2009 and 2011) and information on prior diagnosis of HF. Participants were followed from baseline until the occurrence of one of the study outcomes (see below) or December 2020, the latest date of data availability. Potential confounders included demographic characteristics, anthropometrics (body mass index), lifestyle factors (alcohol consumption, smoking, physical exercise), proxies of socioeconomic status (education, income), medications (major classes of antihypertensive drugs, oral anticoagulants, antiplatelet agents), and comorbidities measured at baseline using face-to-face interviews and administrative healthcare data. The three study outcomes were hospitalization for HF (HHF), cardiovascular death and all-cause mortality. HHF was defined based on inpatient diagnostic codes, and the mortality outcomes were defined based on a combination of administrative healthcare data, death certificates and hospital discharge notes. Cox proportional hazards models estimated hazard ratios (HRs) with 95% confidence intervals (CIs) of the three outcomes associated with decreased kidney function (eGFRBIS2 &lt; 60 mL/min/1.73 m2) compared with retained kidney function (eGFRBIS2 ≥ 60 mL/min/1.73 m2). Analyses were repeated among BIS participants with prior HF.

RESULTS
Our study cohort included 1466 HF free older adults (mean age 79 years; 55% female). Compared with retained kidney function, decreased kidney function was associated with increased risks of HHF (crude incidence rates per 100/year: 2.7 versus 1.1; adjusted HR, 1.48; 95% CI, 1.06–2.07), cardiovascular death (crude incidence rates per 100/year: 2.7 versus 0.9; adjusted HR, 1.49; 95% CI, 1.06–2.09), and all-cause mortality (crude incidence rates per 100/year: 6.3 versus 2.8; adjusted HR, 1.27; 95% CI, 1.03–1.57). Kaplan-Meier curves for the three study outcomes are shown in Figure 1. Among the 590 older adults with prior HF (mean age 83 years; 54% female), the effect estimates were similar albeit less precise (HHF: HR, 1.32; 95% CI, 0.88–1.98/cardiovascular death: HR, 1.67; 95% CI, 1.06–2.63/all-cause mortality: HR, 1.22; 95% CI, 0.91–1.63).

CONCLUSION
Our population-based study showed that decreased kidney function is associated with increased risks of cardiovascular morbidity and cardiovascular and all-cause mortality among older adults, corroborating findings in younger populations.