OBJECTIVEThe analyze the correlation of heart and kidney biomarkers to different heart and kidney diseases and explore the pathogenesis and classification of cardiorenal syndrome.

METHODSThis study involved 841 consecutive patients (600 males and 241 females) admitted between January, 2008 and May, 2008, who underwent NT-ProBNP and creatinine tests during hospitalization. The patients were classified according to the clinical diagnosis at the admission and to the status of the heart and kidney biomarkers.

RESULTSThe heart and kidney biomarkers were significantly different between genders. NT-proBNP showed slight elevations in patients with atrial fibrillation, mild non-heart disease, hypertension and angina, but significant elevation in patients with severe non-heart disease. In patients with renal artery stenosis, the heart and kidney biomarkers were moderately increased, which was also seen in patients with diabetes mellitus, myocardial infarction and coronary artery bypass grafting. In dilated cardiomyopathy and rheumatic heart disease, NT-proBNP showed marked increase with only slight increase of creatinine. Patients with chronic kidney disease had the highest NT-proBNP and creatinine levels and the lowest eGFR. The heart and kidneys index increased with the severity of the disease. From Ronco type I to type IV, NT-proBNP rose gradually, but the difference was not statistically significant (P>0.05), and the type I and IV patients had the highest creatinine level; type III involved mainly acute coronary syndrome, heart failure and renal stenosis. According to a modified classification, cardiarenal syndrome was characterized mainly by a marked increase of NT-proBNP, while renalcardiac syndrome by creatinine increases (P<0.05). Acute coronary syndrome, heart failure and renal artery stenosis represented a special entity of cardiorenal syndrome.

CONCLUSIONSHeart and kidney biomarkers and clinical diagnosis are closely related. The heart and kidneys index more accurately reflects the severity of the cardiorenal syndrome. The heart and kidney biomarkers can be used in Ronco classification. The simplified classification is convenient to use and facilitates the clinical decisions of the treatment.