Ultrasound can be used to determine a patient's cardaic event risk after a transient ischemic attack (TIA). An evaluation of transcranial and extracranial Doppler ultrasonography, published July 30 in BMC Medical Imaging, demonstrated that both future stroke and future cardiovascular ischemic events can be predicted by abnormal findings.
Cardiovascular disease is the major cause of death on long-term follow-up after a TIA, according to the authors. As a result, Holger Poppert, MD, from the Technische Universität München in Germany, and colleagues sought to evaluate the capability of ultrasound to predict the likelihood of new vascular events in 176 TIA patients admitted to the stroke unit, with a median follow-up of 27 months.
The invesigators found that 13.8 percent of patients experienced an ischemic stroke or TIA, 3.1 percent a myocardial infarction or acute coronary syndrome and 3.1 percent underwent arterial revascularization. Extracranial Doppler (ECD) revealed at least 50 percent stenosis or occlusions in 19.3 percent of patients, transcranial Doppler (TCD) showed intracranial stenosis in 9.2 percent and collateral flow patterns due to extracranial stenosis in 3.1 percent of the cohort.
Multivariate analysis identified these abnormal TCD and ECD findings as predictors of new cerebral ischemic events. Abnormal TCD findings were also predictive of cardiovascular ischemic events. In all, 27.8 percent of patients had abnormal transcranial findings, but only 3 percent of patients without abnormal findings developed a subsequent cardiovascular ischemic event.
"Nearly 40 percent of the patients with either stenoocclusive disease in extracranial Doppler or pathological findings in transcranial Doppler suffered a new ischemic stroke or TIA," Poppert said. "Furthermore, detection of reactive collateral flow patterns or intracranial stenosis by transcranial Doppler predicts new cardiovascular ischemic events on medium to long-term follow-up."
The results of the investigation have made Poppert a strong proponent of TCD and ECD as part of the routine workup for TIA patients.
"Our findings support the routine use of transcranial Doppler, in addition to extracranial Doppler in TIA patients," he said. "Moreover, routine screening tests for coronary artery disease and aggressive prevention therapies should be considered in TIA patients with pathological transcranial Doppler findings".
The authors concluded that there is high risk of further cerebral ischemic events in TIA patients with ultrasonographic evidence of extracranial or intracranial stenoocclusive disease during medium- to long-term follow-up.
"As pathological transcranial Doppler findings additionally predict new cardiovascular ischemic events, routine screening tests for CAD and aggressive prevention therapies should be considered in this subgroup of TIA patients. Extracranial Doppler and transcranial Doppler are important diagnostic procedures in patients with TIA," they wrote.