Renal function and peak exercise oxygen consumption in chronic heart failure with reduced left ventricular ejection...

Area of Science:

• Cardiology
• Nephrology
• Exercise Physiology

Background:

• Chronic kidney disease (CKD) is associated with sympathetic nervous system activation and muscle abnormalities, potentially impairing exercise capacity.
• Heart failure (HF) patients often exhibit reduced exercise tolerance, with renal function being a potential contributing factor.

Purpose of the Study:

• To investigate the correlation between estimated glomerular filtration rate (eGFR) and peak exercise oxygen consumption (V̇O2) in a large cohort of systolic heart failure patients.
• To assess the prognostic value of a low peak V̇O2 threshold in predicting adverse outcomes across different levels of renal function.

Main Methods:

• A cohort of 2,938 systolic heart failure patients underwent comprehensive clinical, laboratory, echocardiographic, and cardiopulmonary exercise testing.
• Patients were stratified based on their eGFR levels, and followed for a median of 3.7 years.
• Multivariable regression analysis and survival analysis were used to identify predictors of peak V̇O2 and assess the primary outcome (cardiovascular death or urgent heart transplantation).

Main Results:

• Estimated glomerular filtration rate (eGFR) was a significant independent predictor of peak V̇O2 (P<0.0001) in heart failure patients.
• A peak V̇O2 cutoff of <12 ml·kg(-1)·min(-1) was associated with increased risk of adverse cardiovascular outcomes, with a hazard ratio of 2.72 (P=0.0489) in patients with eGFR <45 ml·min(-1)·1.73 m(-2).
• The prognostic utility of this peak V̇O2 cutoff, as indicated by the area under the receiver-operating characteristic curve, was limited in patients with more severely impaired renal function.

Conclusions:

• Renal dysfunction is significantly correlated with reduced peak exercise oxygen consumption (V̇O2) in heart failure patients.
• A peak V̇O2 threshold of 12 ml·kg(-1)·min(-1) offers diminished prognostic value for predicting adverse cardiovascular events in heart failure patients with severely compromised renal function.