Blood biomarkers currently do not have diagnostic value for patients with suspected transient ischemic attack (TIA), indicating that the sudden onset of symptoms and “onset in full intensity” are still the most valuable clinical predictors of TIA and minor stroke, according to study results published in BMJ Open.
Investigators conducted a cross-sectional diagnostic accuracy study to determine how valuable serum biomarkers would be in diagnosing patients suspected of TIA. The study, which had a 6-month follow-up period, included 206 participants who were suspected of TIA by a general practitioner. Blood samples were taken from each patient within 72 hours of symptom onset. Serum biomarkers monitored included NR2, NR2 antibodies, PARK7, NDKA1, UFD1, B-FABP, and H-FABP. A total of 3 expert neurologists classified each case as TIA, minor stroke, or any other diagnosis, and statistical analysis quantified diagnostic accuracy.
Of the 206 patients, 61.2% were diagnosed with TIA or minor stroke by the panel of neurologists. Median time from symptom onset to blood sample collection was 48.0 hours. Of the 7 biomarkers included in the analysis, none of them was valuable in TIA diagnosis, with C-statistics between 0.45 and 0.58, which did not increase with the addition of each biomarker. A total of 8 clinical predictors, including increasing age, a history of coronary artery disease, sudden onset of symptoms, occurrence of symptoms in full intensity, dysarthria, no history of migraine, absence of loss of consciousness, and absence of headache, made up the final multivariable model with a C-statistic of 0.83.
“Although the results of this study do not favour the use of biomarkers, the idea of a blood test providing evidence for transient cerebral ischaemia remains appealing,” the authors noted.
“Future studies evaluating biomarkers that are influenced by early degradation, like NR2, should consider immediate measurement by point-of-care tests in the outpatient setting. Furthermore, serial measurements in patients with TIA could gain more insight into the course of biomarker levels within the first days,” they concluded.
Dolmans LS, Rutten F, Bartelink M-LEL, et al. Serum biomarkers in patients suspected of transient ischaemic attack in primary care: a diagnostic accuracy study. BMJ Open 2019;9:e031774.