Cardiorenal syndrome： pathophysiological mechanism, preclinical models, novel contributors and potential therapies

Objective To review the current knowledge about the pathophysiological mechanisms,preclinical models,novel contributors and potential therapies of cardiorenal syndrome.Data sources The literature concerning cardioranal syndrome in this review was collected from PubMed published in English up to January 2014.Study selection Original articles and critical reviews related to cardiorenal syndrome were selected and carefully analyzed.Results Cardiorenal syndrome is a condition characterized by kidney and heart failure where failure of one organ worsens the function of the other thus further accelerating the progressive failure of both organs.The pathophysiology of cardiorenal syndrome is not fully understood,but may be caused by a complex combination of neurohormonal system activation,endothelial dysfunction,proteinuria,oxidative stress,uremic toxins and other factors.Managing cardiorenal syndrome is still a major therapeutic challenge in clinical practice because many of the drugs used to control heart failure can worsen renal function,and vice versa.Non-dialyzable uremic toxins,such as indoxyl sulfate,causing detrimental effects on the heart and kidney as well as stimulation of inflammatory responses,may be an effective therapeutic target for cardiorenal syndrome.Conclusions Suitable disease models of cardiorenal syndrome are urgently needed to investigate the pathophysiology and effective therapeutic approaches to the condition.Non-dialyzable protein-bound uremic toxins that may have cardiac and renal effects may provide therapeutic benefit to cardiorenal syndrome patients.

Renal denervation： a new therapeutic approach for resistant hypertension

Objective To review the advances in studies on renal denervation. Data sources References concerning renal denervation and resistant hypertension cited in this review were collected from PubMed published in English and those of renal denervation devices from official websites of device manufacturers up to January 2014. Study selection Articles with keywords ＂renal denervation＂ and ＂resistant hypertension＂ were selected. Results Renal and systemic sympathetic overactivity plays an important role in pathology of hypertension as well as other diseases characterized by sympathetic overactivity. Renal denervation is a new, catheter based procedure to reduce renal and systemic sympathetic overactivity by disruption of renal sympathetic efferent and afferent nerves through radiofrequency or ultrasound energy delivered to the endoluminal surface of both renal arteries. Although several studies have shown the efficacy and safety of renal denervation in the treatment of resistant hypertension and the potential benefit of the procedure in other diseases, Symplicity HTN 3 study, the most rigorous clinical trial of renal denervation to date, failed to meet its primary endpoint. The procedure also has other limitations such as the lack of long term, efficacy and safety data and the lack of the predictors for the blood pressure lowering response and nonresponse to the procedure. An overview of current renal denervation devices holding Conformite Europ6enne mark is also included in this review. Conclusions Renal denervation is a promising therapeutic approach in the management of resistant hypertension and other diseases characterized by sympathetic overactivity. In its early stage of clinical application, the efficacy of the procedure is still controversial. Large scale, blind, randomized, controlled clinical trials are still necessary to address the limitations of the procedure.