NPPB and hypertensive disorder: Since NT-proBNP clearance occurs only in the kidney, elevated levels may result from decreasing renal function because of increased intravascular volume, in addition to impaired cardiac function.34 Extravascular volume expansion is known to be an important mechanism in the pathophysiology of hypertension in CKD,35 which may explain the correlation in the setting of TIA or stroke in this study.