| [ Summary ] |
Patients with very low GFR or on dialysis are at increased risk for haemorrhagic stroke. The presumed mechanism is the effect of uraemia on platelet functions or perhaps the relationship between GFR and cerebral small-vessel disease. Warfarin is commonly used to prevent strokes in patients with atrial fibrillation. However, patients on haemodialysis may not derive the same benefits from warfarin as the general population. There are no randomized controlled studies of dialysis patients which demonstrate the efficacy of warfarin in preventing strokes. In fact, warfarin places dialysis patients at increased risk for haemorrhagic stroke and possibly ischaemic stroke. Additionally, warfarin increases the risk of major bleeding and has been associated with vascular calcification. Routine use of warfarin in conjunction with dialysis for stroke prevention should be discouraged. Therapy should only be reserved for dialysis patients at high risk of thrombo-embolic stroke and carefully monitored if implemented. All decisions regarding anticoagulation depend on an assessment of risk and benefits for individual patients. Blood pressure control plays an important role in prevention of strokes in the general population. In patients receiving hemodialysis, predialysis and postdialysis blood pressure goals should be < 140/90 mmHg and < 130/80 mmHg, respectively. Management of hypertension in dialysis patients requires attention to both management of fluid status and adjustment of antihypertensive medications. A limitation of these guidelines is due to the lack of large-scale clinical trials correlating levels of blood pressure with stroke events. Particularly puzzling is the U-shaped relationship between systolic blood pressure and cardiovascular morbidity and mortality, and the apparent lack of high blood pressure effects on stroke events until systolic blood pressure reaches approximately 180 mmHg. The increased mortality in patients with lower blood pressure could be related to poor ventricular function. The lack of effects of blood pressure on stroke events over a wide range of blood pressure between 100-180 mmHg may be related to variable ventricular function. A great variability in blood pressure connected with dialysis and the lack of firm criteria on the definition of hypertension in this patient population exists. |