Cardiorenal syndrome

Patients with cardiorenal syndrome (CRS) suffer from extremely high levels of morbidity and mortality. The pathophysiology of the CRS involves inter-related hemodynamic and neurohormonal mechanisms including the renin–angiotensin–aldosterone system (RAAS), endothelin, and arginine–vasopressin system activation. The management of CRS remains a challenge despite extensive research into the pathophysiology, discovery of new biomarkers, and ongoing drug trials. This article reviews some of the most important trials for patients with acute decompensated heart failure and CRS using diuretics, vasodilator, levosimendan (a calcium sensitizer), vasoactive and neurohormonal therapies, and finally ultrafiltration for refractory cases. In addition, the trials of a new agent that combines angiotensin-receptor blockade with neprilysin inhibition (enhancing endogenous natriuretic peptide action), and of a new recombinant human relaxin-2 called serelaxin are discussed. For chronic CRS, the blockade of the RAAS and levosimendan given in repetitive dosing is discussed. Finally, some data on how the newer generation devices such as left ventricular assist device may improve outcome of CRS are presented; additionally, some new ideas about prevention and treatment of calcification-induced congestive cardiac failure in renal patients are presented. 心腎綜合症(CRS, cardiorenal syndrome)是嚴重的疾病，死亡率極高，其致病過程涉及一系列血行動力-神經內分泌機轉的變化，包括腎素-血管緊縮素-醛固酮系統(RAAS, renin–angiotensin–aldosterone system)、內皮素(endothelin)及抗利尿素(arginine–vasopressin)系統的活化。至今，即使已有大量關於病理生理學、生物標識物、及藥物治療的研究問世，然而CRS仍然是臨床上的一大挑戰。本文將針對合併有CRS的急性失代償性心衰竭 (ADHF)患者，回顧利尿劑、血管擴張劑、levosimendan (鈣增敏劑)、血管活性及神經內分泌療法的相關重要研究，更會回顧超過濾(UF, ultrafiltration)在頑抗性個案間的治療表現。此外，我們亦會探討利鈉肽(NPs, natriuretic peptides)或神經荷爾蒙藥物的潛在效用，包括一種兼具血管緊縮素受體阻斷(ARB)與neprilysin抑制作用(促進內源性NP活動)的新藥物、及一種新的重組人類relaxin-2 (稱為serelaxin)。至於慢性CRS，我們主要著眼於RAAS阻斷劑與levosimendan的重複給藥、及腹膜透析(PD)