Decreased renal function in hypertensive emergencies.

Data about acute renal function in hypertensive crises are scarce. We hypothesised that acute kidney damage could result from hypertensive emergency (HE), as indicated by the earliest biomarker of kidney injury, neutrophil gelatinase-associated lipocalin (NGAL). Thus, we compared renal function between patients with HE, patients with urgencies and normotensive controls. Sixty emergency department patients were enroled in a prospective, cross-sectional study. Creatinine, blood urea nitrogen (BUN), NGAL and cystatin C were measured and estimated glomerular filtration rate was calculated (eGFR). Creatinine and BUN were significantly higher and eGFR was significantly lower in HE as compared with urgencies or controls (P < 0.01). Similarly, cystatin C and NGAL levels were significantly higher in emergencies compared with the other groups (P < 0.001). All renal function parameters were similar between urgencies and controls. Among HE, NGAL was significantly higher (61%) in patients with pulmonary oedema than in those with cerebral events (P = 0.008), whereas the other parameters were not significantly different. In conclusion, this cross-sectional investigation showed that markers of acute and chronic kidney injury were higher in patients with HE than in urgencies or controls. These results should encourage further studies to better characterise the role of acute kidney damage in hypertensive pulmonary oedema, and HE in general.

Hypertensive emergencies are associated with elevated markers of inflammation, coagulation, platelet activation and fibrinolysis.

Data from in vitro and animal experiments suggest that progressive endothelial damage with subsequent activation of coagulation and inflammation have a key role in hypertensive crisis. However, clinical investigations are scarce. We hypothesized that hypertensive emergencies are associated with enhanced inflammation, endothelial- and coagulation activation. Thus, we enrolled 60 patients admitted to an emergency department in a prospective, cross-sectional study. We compared markers of coagulation, fibrinolysis (prothrombin fragment F(1+2), plasmin-antiplasmin complexes, plasmin-activator inhibitor, tissue plasminogen activator), platelet- and endothelial activation and inflammation (P-selectin, C-reactive protein, leukocyte counts, fibrinogen, soluble vascular adhesion molecule-1, intercellular adhesion molecule-1, myeloperoxidase and asymmetric dimethylarginine) between hypertensive emergencies, urgencies and normotensive patients. In hypertensive emergencies, markers of inflammation and endothelial activation were significantly higher as compared with urgencies and controls (P<0.05). Likewise, plasmin-antiplasmin complexes were 75% higher in emergencies as compared with urgencies (P<0.001), as were tissue plasminogen-activator levels (∼30%; P<0.05) and sP-selectin (∼40%; P<0.05). In contrast, similar levels of all parameters were found between urgencies and controls. We consistently observed elevated markers of thrombogenesis, fibrinolysis and inflammation in hypertensive emergencies as compared with urgencies. Further studies will be needed to clarify if these alterations are cause or consequence of target organ damage.