Long-term verification of functional and structural renal damage after renal sympathetic denervation

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.

Evaluation of cystatin C and neutrophil gelatinase-associated lipocalin as predictors of mortality in patients undergoing percutaneous mitral valve repair (MitraClip)

BACKGROUND

Compromised renal function is a major risk factor that is strongly associated with poor outcome in patients with mitral regurgitation (MR) and heart failure. Cystatin C, a cysteine protease inhibitor, has been used as a specific and sensitive biomarker of renal function. Neutrophil gelatinase-associated lipocalin (NGAL) is another sensitive biomarker that specifically indicates functional and structural kidney damage. The aim of the present study was to determine the predictive value of serum cystatin C and urinary NGAL as indicators of mortality in patients undergoing percutaneous mitral valve repair (PMVR).

METHODS

A total of 120 consecutive patients (age: 77.3 years [±11.2]) undergoing PMVR using the MitraClip system were included in this study. Venous blood and urinary samples were collected for biomarker analysis prior to PMVR. Physiological parameters, medication use, safety events, and all-cause mortality were assessed 12 months after the procedure.

RESULTS

Twelve months after PMVR, there was a significant reduction in the severity of MR (P < 0.001), and an improvement in the New York Heart Association class (P < 0.01) was documented. Baseline levels of serum cystatin C (nonsurvivors: 2.4 mg/L [interquartile, IQR: 1.7;3.1] vs survivors: 1.7 mg/L [IQR: 1,3;2.1], P < 0.001) and urinary NGAL (nonsurvivors: 242.0 ng/mL [IQR: 154.5;281.5] vs survivors: 132.0 ng/mL [IQR:107.0;177.3], P < 0.001) were significantly higher in patients who died during the 12-month follow-up period.

CONCLUSION

Cystatin C and urinary NGAL were found to be predictors of long-term mortality in high-risk patients undergoing PMVR. Thus, cystatin C and NGAL assessment may be helpful in risk stratification in patients undergoing PMVR.