Kidney Function and Outcomes in Heart Failure Inpatients

Quick Takes

  • Kidney disease is widely prevalent in hospitalized HF patients with 64% of hospitalizations associated with eGFR <60.
  • In-hospital mortality increased with lower admission eGFR and this association was steepest in patients with HF with reduced EF.
  • Use of guideline-directed medical therapy at discharge decreased with rising eGFR.

Study Questions:

What are the clinical profiles, discharge medical therapies, and in-hospital mortality among patients hospitalized for heart failure (HF) across the spectrum of kidney function?

Methods:

This was a retrospective analysis of all hospitalizations from January 1, 2014–September 30, 2019, across 529 sites participating in the Get With the Guidelines–Heart Failure (GWTG-HF) registry who had data available on estimated glomerular filtration rate (eGFR). Patients were characterized as HF with reduced ejection fraction (HFrEF; EF ≤40%), HF with mid-range EF (HFmEF; 41-49%), and HF with preserved EF (HFpEF; EF ≥50). Patients were stratified into six groups based on the eGFR groups: ≥90, 60 to <90, 45 to <60, 30 to <45, <30 ml/min/1.73 m2, and on dialysis. Analysis was performed at the level of hospitalizations and not individual patients.

Results:

A total of 365,494 HF hospitalizations were included across 418 sites with a mean age of 72 ± 15 years and median eGFR of 51. Overall, 5% were on dialysis, 64% had eGFR <60, and 10% had an eGFR >90. Over time, the proportion of patients within each eGFR category did not change. Among patients not on dialysis, those with lower eGFR more likely to be women, of white race, and older. Lower renal function was associated with higher EF and higher prevalence of comorbidities such as hypertension, diabetes, and coronary and peripheral artery disease. Patients with lower renal function had higher rates of potassium ≥5 mEq and ≥5.5 mEq. There was a significant inverse association between admission eGFR and in-hospital mortality. This association was steepest for HFrEF. Among HFrEF patients, there was a significant decrease in use of beta-blockers, mineralocorticoid receptor antagonists, and angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers/angiotensin receptor neprilysin inhibitors. Rates of hydralazine/nitrate use increased with lower eGFR, but the overall rates were low (<1% in all eGFR categories). Post-hospitalization follow-up rates declined with worsening renal function.

Conclusions:

In a large, contemporary cohort of HF patients, 64% of patients had chronic kidney disease with an eGFR <60, with no change in this proportion over time. Lower renal function was associated with higher in-hospital mortality and lower likelihood of receiving guideline-directed medical therapy.

Perspective:

Renal dysfunction in HF patients can exist due to overlapping pathophysiology or due to common risk factors. In this study, 64% of hospitalized HF patients had evidence of kidney disease. In addition, mortality rates increased substantially with worsening renal function. Despite this association, rates of use of guideline-directed medical therapy declined with worsening renal function even when not contraindicated by renal function and potassium levels. Although this patient population is at a higher risk, post-hospitalization follow-up rates were lower. Important limitations include analysis of hospitalizations, as opposed to individual patient-level data, and lack of lab data on all participants.

Clinical Topics: Geriatric Cardiology, Heart Failure and Cardiomyopathies, Prevention, Vascular Medicine, Atherosclerotic Disease (CAD/PAD), Acute Heart Failure, Heart Failure and Cardiac Biomarkers, Hypertension

Keywords: Angiotensin-Converting Enzyme Inhibitors, Angiotensin Receptor Antagonists, Diabetes Mellitus, Geriatrics, Glomerular Filtration Rate, Heart Failure, Hospital Mortality, Hydralazine, Hypertension, Kidney Diseases, Mineralocorticoid Receptor Antagonists, Neprilysin, Nitrates, Patient Discharge, Peripheral Arterial Disease, Potassium, Receptors, Angiotensin, Renal Dialysis, Renal Insufficiency, Chronic, Stroke Volume


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