The Stroke Society of Australasia held its Stroke 2021 Conference from 12 – 15 October 2021 as a virtual meeting and also at the Perth Convention and Exhibition Centre, Western Australia. The SSA conference included many presentations by Australian neurologists on issues such tele-stroke services, thrombolysis and stroke prevention with anticoagulation. Here are five highlights from the varied content in the program.
Strokes often linked to anticoagulation issues
Most strokes that occur in patients with atrial fibrillation are associated with poor anticoagulation practice, a study by Victorian neurologists has shown. In a retrospective review, clinicians at Austin Hospital, Melbourne identified anticoagulation ‘management issues’ in two thirds of 304 patients with AF and ischaemic stroke patients admitted to the hospital stroke unit in between 2016 and 2019. Of those with management issues in the two week prior to admission (as defined using European Heart Rhythm Association criteria), 36% were not prescribed any anticoagulation despite increased stroke risk and absence of contraindications and 20% had anticoagulation inappropriately ceased. Mortality at three months was 32% in those with management issues, compared to 17% in the appropriately anticoagulated group. Patients with management issues tended to be older and more often female. “Inappropriate management of anticoagulants is present in the majority of acute ischaemic stroke in the two weeks preceding the event and is linked to higher mortality. Improved anticoagulation practice has the potential to substantially reduce stroke rates in patients with AF,” they concluded.
Good outcomes for long distance ‘drip and fly’ LVO stroke management
Rural and remote stroke patients with large vessel occlusion (LVO) have good outcomes when aero-medically transferred long distance for endovascular thrombectomy (EVT), a Queensland study has shown. The outcomes for 20 LVO stroke patients who were flown an average of 1350km from ten rural and remote Queensland sites to have EVT, were comparable to patients who were transferred locally to the Gold Coast University Hospital thrombectomy centre. The ‘drip and fly’ patients had a median time of ictus to recanalisation of 928 minutes compared to 240 minutes, for direct transfer patients and symptomatic intracranial haemorrhage rate was similar in both groups (5%). At 90 days, functional independence (Modified Rankin Scale 0–2) was achieved in 45% of patients in drip and fly group compared to 51.5% in direct to mothership group. “This is an exciting result because these patients are coming from areas where stroke treatment is not available on site,” project supervisor Dr Darshan Shah said. “While distance is a big obstacle, it should not mean greater disability or even death. All Australians deserve access to time-critical treatment we know saves lives.” Stroke Society of Australasia (SSA) President Professor Bernard Yan said the findings were encouraging, because rural and regional Australians are 17% more likely to have a stroke than people in metropolitan areas. “We must invest in technology that speeds up diagnosis of stroke and delivery of emergency treatment,” Professor Yan said. “There is much work currently underway to address the disparity of distance, including reducing the size and weight of brain scanners so they can be utilised on aircraft,” he added.
Incidental findings common on CT imaging in acute stroke patients
Incidental findings are common on routinely preformed CT for suspected acute stroke, clinicians in WA have shown. A review of radiology reports of 500 consecutive acute stroke calls at two large metropolitan stroke centres found that 31% had incidental findings, with thyroid nodules and unruptured intra-cranial aneurysms the most common. Other incident findings included variant anatomy, pulmonary nodules and pleural effusions. Most findings required some form of management or follow up but did not alter the management of the stroke, the study investigators said. “Whilst these conditions did not impact on acute stroke management, they may potentially be important on overall patient care, and may have medic-legal consequences if not followed up appropriately,” said the researchers, led by Dr Muhammed Zubair, a neurologist at the Sir Charles Gairdner Hospital, Perth. Location and outcome after acute ischaemic stroke: the ENCHANTED trial.
Circulation location influences outcome after acute stroke
Thrombolysed anterior circulation acute ischaemic stroke (ACS) is associated with better clinical outcomes than posterior circulation (PCS) stroke, an Australian-led study has shown. A review of outcomes for 2916 patients enrolled in the alteplase-dose arm of ENhanced Control of Hypertension ANd Thrombolysis strokE stuDy (ENCHANTED) found that ACS (n = 1553) was associated with less dependency (Odds Ratio 0.57) and 90-day death (OR 0.46 than PCS (n = 1363).However there was no difference in 24-hour and 7-day death (OR 0.88 and 1.02, respectively) or symptomatic intracerebral haemorrhage (sICH) between the two groups. In the middle cerebral artery (MCA) territory, superficial stroke was associated with better outcome than deep, for dependency (OR 0.73) and 24-hour and 7-day death (OR 0.62 and 0.65 respectively) but there was no difference in day-90 death and sICH. The researchers, led by Dr Candice Delcourt Head of the Neurology Program at The George Institute, Sydney, concluded that the safety of thrombolysis did not differ between ACS and PCS but the latter had worse functional outcomes.
Intracranial atherosclerosis common in stroke patients
Intracranial atherosclerosis is common and often underdiagnosed in stroke patients, according to results from an Australian tertiary stroke care unit. A retrospective review of CT angiography (CTA) records for 949 patients admitted to the Royal Melbourne Hospital (RMH) Stroke Care Unit in 2019–2020 found that 13% had possibly symptomatic intracranial atherosclerosis. Of these cases, two thirds were diagnosed by radiology and one third were diagnosed by the stroke team. Intracranial atherosclerosis patients with multiple possible aetiologies were significantly less likely to have intracranial atherosclerosis diagnosed by the stroke team (17% vs 46%), the study investigators noted. “ICAD is a significant contributor to stroke burden at a major tertiary Stroke Care Unit,” concluded the researchers, led by Dr Davor Pavlin-Premrl. “The routine use of CTA allows the condition to be diagnosed without the burden of additional investigations. However, the condition may be underdiagnosed by both radiologists and stroke physicians,” they added.