Antithrombotic treatment of cerebrovascular disease

Serum anion gap at admission predicts all-cause mortality in critically ill patients with cerebral infarction: evidence from the MIMIC-III database

BACKGROUND

Recent studies reported that serum anion gap could be regarded as a prognostic biomarker for patients admitted to intensive care units. However, the association between AG and mortality in cerebral infarction patients remained largely unknown.

METHODS

Relevant clinical data were collected from Medical Information Mart for Intensive Care III. Patients were divided into three groups according to tertiles of AG. Kaplan-Meier curve and Cox proportional hazards models were used to evaluate the association between AG levels and all-cause mortality. Subgroup analyses were performed to verify the predictive role of AG on mortality.

RESULTS

Kaplan-Meier analysis showed that patients with higher AG had shorter survival time. Cox regression model indicated high AG as an independent risk factor of 30-day, 60-day and 180-day all-cause mortality (30-day: HR = 2.45, 95% CI = 1.21-4.97, 60-day: HR = 2.04, 95% CI = 1.07-3.89, and 180-day: HR = 1.85, 95% CI = 1.02-3.36). However, no significance was observed between AG and 365-day all-cause mortality (HR = 1.56, 95% CI = 0.87-2.78).

CONCLUSIONS

High AG was associated with increased risk of all-cause mortality, and AG could be an independent short-term prognostic factor for cerebral infarction.

The use of aspirin in polycythaemia vera and primary thrombocythaemia

In polycythaemia vera (PV; polycythaemia rubra vera, primary proliferative polycythaemia) and primary thrombocythaemia (PT; essential thrombocythaemia), occlusive complications in the microvasculature and larger vessels are a significant cause of morbidity and mortality. Central to the pathogenesis of these complications are the quantitative and qualitative platelet changes present in these myeloproliferative disorders. Aspirin irreversibly inactivates cyclo-oxygenase in platelets. This leads to a reduced production of platelet thromboxane A2 which has vasoconstricting and platelet aggregatory properties. In haematologically normal individuals, aspirin has been shown to reduce thrombo-embolic complications in populations at risk of these events. In PV and PT, aspirin has been shown to specifically eliminate the micro-circulatory and vasomotor manifestations and there is some evidence of a reduction in larger vessel occlusion. Low-dose aspirin has been shown to substantially reduce the raised thromboxane A2 production of platelets in PV and PT patients. The incidence of haemorrhagic side-effects of aspirin are minimized by the use of low doses. Haemorrhagic events are particularly found in patients with platelet counts > 1000 x 10(9)/l and these events are enhanced by aspirin therapy in these patients. Aspirin should be used with caution in patients with dyspeptic symptoms or a history of peptic ulceration or bronchospasm. Precise PCV control (< 0.45) and cytoreduction (platelets < 400 x 10(9)/l) should be used in patients with PV to minimize the vascular occlusion risk but routine cytoreduction is proposed only for those at particular risk of vascular occlusion in PT. In the acute presentation of patients with vascular occlusion, cytoreduction and an aspirin dose of 300 mg a day is proposed, reducing to 75 mg a day with the control of symptoms and signs, while 75 mg a day may play a role as prophylactic therapy in the prevention of thrombosis. However, there are no prospective studies in PT to demonstrate the benefit/risk profile and to confirm these recommendations, while a randomized prospective placebo-controlled study of low-dose aspirin in PV has only recently been initiated.