Real-Life Use of Neurohormonal Antagonists and Loop Diuretics in Chronic Heart Failure: Analysis of Serial Biomarker Measurements and Clinical Outcome

Fibrosis, the Bad Actor in Cardiorenal Syndromes: Mechanisms Involved

Cardiorenal syndrome is a term that defines the complex bidirectional nature of the interaction between cardiac and renal disease. It is well established that patients with kidney disease have higher incidence of cardiovascular comorbidities and that renal dysfunction is a significant threat to the prognosis of patients with cardiac disease. Fibrosis is a common characteristic of organ injury progression that has been proposed not only as a marker but also as an important driver of the pathophysiology of cardiorenal syndromes. Due to the relevance of fibrosis, its study might give insight into the mechanisms and targets that could potentially be modulated to prevent fibrosis development. The aim of this review was to summarize some of the pathophysiological pathways involved in the fibrotic damage seen in cardiorenal syndromes, such as inflammation, oxidative stress and endoplasmic reticulum stress, which are known to be triggers and mediators of fibrosis.

Renal tubular damage and worsening renal function in chronic heart failure: Clinical determinants and relation to prognosis (Bio-SHiFT study)

Background

It is uncertain that chronic heart failure (CHF) patients are susceptible to renal tubular damage with that of worsening renal function (WRF) preceding clinical outcomes.

Hypothesis

Changes in tubular damage biomarkers are stronger predictors of subsequent clinical events than changes in creatinine (Cr), and both have different clinical determinants.

Methods

During 2.2 years, we repeatedly simultaneously collected a median of 9 blood and 8 urine samples per patient in 263 CHF patients. We determined the slopes (rates of change) of the biomarker trajectories for plasma (Cr) and urinary tubular damage biomarkers N‐acetyl‐β‐d‐glucosaminidase (NAG), and kidney‐injury‐molecule (KIM)‐1. The degree of tubular injury was ranked according to NAG and KIM‐1 slopes: increase in neither, increase in either, or increase in both; WRF was defined as increasing Cr slope. The composite endpoint comprised HF‐hospitalization, cardiac death, left ventricular assist device placement, and heart transplantation.

Results

Higher baseline NT‐proBNP and lower eGFR predicted more severe tubular damage (adjusted odds ratio, adj. OR [95%CI, 95% confidence interval] per doubling NT‐proBNP: 1.26 [1.07‐1.49]; per 10 mL/min/1.73 m² eGFR decrease 1.16 [1.03‐1.31]). Higher loop diuretic doses, lower aldosterone antagonist doses, and higher eGFR predicted WRF (furosemide per 40 mg increase: 1.32 [1.08‐1.62]; spironolactone per 25 mg decrease: 1.76 [1.07‐2.89]; per 10 mL/min/1.73 m² eGFR increase: 1.40 [1.20‐1.63]). WRF and higher rank of tubular injury individually entailed higher risk of the composite endpoint (adjusted hazard ratios, adj. HR [95%CI]: WRF 1.9 [1.1‐3.4], tubular 8.4 [2.6‐27.9]; when combined risk was highest 15.0 [2.0‐111.0]).

Conclusion

Slopes of tubular damage and WRF biomarkers had different clinical determinants. Both predicted clinical outcome, but this association was stronger for tubular injury. Prognostic effects of both appeared independent and additive.