The relationship between acute ischaemic stroke and plasma D-dimer levels in patients developing neither venous thromboembolism nor major intercurrent illness.

The true relationship between plasma D-dimers and acute ischaemic stroke (AIS) is uncertain as previous studies investigating this have not screened for subclinical deep vein thrombosis. We addressed this as part of a study in which we screened AIS patients for venous thromboembolism (VTE). We also assessed the performance characteristics of two D-dimer assays as exclusionary tests for VTE in these patients. One hundred and two unselected AIS patients were screened for VTE using magnetic resonance direct thrombus imaging. D-dimers were analysed on days 2, 9, 14 and 21 using the VIDAS immunofluorescent assay (cut-off >or= 500 ng/ml) and the IL test D-dimer immunoturbidimetric assay (cut-off >or= 255 ng/ml). The relationship between D-dimers and AIS was examined in 52 patients neither developing VTE nor intercurrent illness. D-dimers were elevated throughout the study. Median values at the four time points were 652, 692, 737 and 686 ng/ml (VIDAS assay) and 260.5, 268.5, 273 and 283 ng/ml (IL assay). D-dimers were higher in patients aged older than 70 years, with severe stroke or with total anterior circulation infarcts: only age older than 70 years was significantly associated with D-dimer values greater than the median on univariate and multivariable analysis. Both assays were 100% sensitive for VTE. Specificities were 30% (VIDAS assay) and 34% (IL assay). Specificity was adversely affected by age older than 70 and severe versus non-severe stroke. D-dimers are elevated in the first 3 weeks post-AIS after eliminating the confounding effect of subclinical deep vein thrombosis. The VIDAS and IL assays remained sensitive tests for VTE but the specificity was low, limiting their exclusionary efficiency in these patients.

Pulmonary embolism and pneumonia may be confounded after acute stroke and may co-exist.

Pulmonary embolism and pneumonia are prevalent complications after acute stroke that overlap significantly in their timing, risk factors and clinical features. Consequently, confounding and co-existence of these diagnoses can occur and is probably commoner than is generally appreciated. Correct identification of pulmonary embolism in these patients is important as the mortality of this condition following stroke is higher than in unselected patients. Clinicians should have a low threshold for suspicion of, and objective testing for, pulmonary embolism in stroke patients with acute cardiorespiratory symptoms, even if an alternative diagnosis is evident.

Ischaemic hepatitis in the elderly.

BACKGROUND: Ischaemic hepatitis is centrilobular necrosis which is usually associated with an acute cardiovascular event and in a general hospital setting has been considered to be a rare condition. It is though thought to be frequently unrecognized, which is important as it has implications for both investigations and drug therapy. Previous reports have not focused on the elderly. OBJECTIVES: (1) To determine the incidence of ischaemic hepatitis in elderly patients admitted to a Department of Geriatric Medicine and (2) to assess both the clinical and biochemical features of the condition. METHODS: 1,905 elderly patients (1,270 F, 635 M) admitted consecutively to our department over a 2-year period were assessed prospectively. All were aged > or =65 years (mean 78, range 65-98). Ischaemic hepatitis was diagnosed by a rapid development of abnormal liver function tests of hepatocellular type in acutely ill patients in whom a fall in blood pressure occurred and other causes of liver dysfunction were excluded. The admission, lowest and subsequent blood pressures were recorded. Daily renal and liver function tests, including prothrombin times, were measured during the acute illness. RESULTS: Nineteen patients (1%) developed ischaemic hepatitis. The clinical picture was dominated by the causal condition, the commonest being left ventricular failure (12 patients). The mean fall in systolic, diastolic and mean blood pressures were 61, 44 and 48 mm Hg, respectively. Within 3 days the alanine aminotransferase increased to more than 5 times normal and there were marked elevations of the lactic dehydrogenase. In those who survived, the liver enzymes returned to normal within 7-22 days (mean 13). The prothrombin time was prolonged to >20 s in 6 patients (32%). Six patients died, 5 from left ventricular failure; the mean creatinine in 5 of those who died was 244 micromol/l (range 174-355) and in each the urea was >25 micromol/l. CONCLUSION: Ischaemic hepatitis is an uncommon but not rare condition in elderly patients admitted acutely to a Department of Geriatric Medicine. There was a dramatic rise in liver enzymes which in survivors returned to normal within 3 weeks. Clinical features were dominated by the causal condition and a third of the patients died.

Plasma D-dimers in the diagnosis of venous thromboembolism.

Clinical suspicion for venous thromboembolism (VTE) mandates objective testing to confirm or exclude the diagnosis. However, current imaging modalities are imperfect because of a small but important risk of complications with invasive techniques or limited sensitivity with noninvasive ones. A diagnostic tool for VTE is needed that is noninvasive and highly accurate, allowing immediate treatment decisions to be made in most cases. Plasma D-dimers (D-ds), specific cross-linked fibrin derivatives, partially fulfill these criteria in that they are sensitive markers for thrombosis but lack specificity. They therefore cannot be used to make a positive diagnosis of VTE; however, they generally have high negative predictive value and are useful as an exclusionary test, a potentially important role given that VTE is eventually ruled out in most patients investigated. Clinical management studies are clarifying the role of D-ds in the diagnostic paradigm of VTE: negative ultrasound and D-d findings obviate the need for serial imaging in suspected deep vein thrombosis, and anticoagulant therapy can be safely withheld in patients with non-high clinical suspicion for pulmonary embolism and non-high probability ventilation perfusion scan if D-d test results are negative. More recently, the combination of a negative SimpliRED (AGEN Biomedical Ltd, Brisbane, Australia) D-d result and low clinical suspicion derived using a formal scoring system has been shown to exclude deep vein thrombosis and pulmonary embolism and to obviate the need for imaging. Several different D-d assays are now available, and clinicians should be aware of the performance characteristics of the test used before incorporation into diagnostic algorithms as these will differ between assays, and the results of clinical management studies cannot necessarily be safely extrapolated to assays other than those specifically evaluated. If alternative assays are to be substituted, these should consistently have been shown to possess equivalent or greater sensitivity.