Advancements in diagnostic and interventional radiology for stroke treatment: the path from trial to bedside through the pre-MR CLEAN, MR CLEAN, and MR CLEAN II eras.

The stroke field is inevitably connected with imaging in which radiologists fulfill a central role. Our landmark MR CLEAN trial led to the implementation of baseline computed tomography angiography or magnetic resonance angiography in the acute stroke workup and subsequent endovascular treatment (EVT) for ischemic stroke patients with a large vessel occlusion in the anterior circulation, resulting in numerous patients worldwide currently being treated often successfully. A reversal of the pathophysiologic process behind an acute cerebrovascular event was made possible. Subsequently, in the MR CLEAN II trials, the clinical impact of both diagnostic and interventional radiologists remained a cornerstone of our research, which means value-based radiology. Within these MR CLEAN II trials, we proved that aspirin and heparin during EVT should be avoided due to increased symptomatic intracranial hemorrhage risk (MR CLEAN-MED). We concluded there is additional benefit of EVT in the 6-to-24-h window after stroke in the presence of good collaterals on baseline CTA (MR CLEAN-LATE). The impactful success of our stroke trials that changed many guidelines was mainly attributable to (1) the societal burden of the disease, with two thirds of patients dying or being independent at 3 months; (2) the fact that stroke is a common disease, (3) the relatively simple and pragmatic approach of the trials resembling real-world setting; (4) the acceleration of implementation in clinical practice facilitated by a structured approach to guideline development and conditional funding; and foremost (5) the excellent collaboration on a professional level between-disciplines, i.e., diagnostic radiologists, interventionalists, and neurologists.Critical relevance statement The MR CLEAN and MR CLEAN II trials have had tremendous impact on clinical practice, directly by more patients being treated with an effective intervention and indirectly through adoption of evidence-based guidelines. It is in this setting of stroke treatment that diagnostic and interventional radiologists have played a crucial role and created clinical impact.

Cost-effectiveness of Direct Transfer to Angiography Suite of Patients With Suspected Large Vessel Occlusion.

BACKGROUND AND OBJECTIVES: Patients with acute ischemic stroke due to large vessel occlusion (LVO) deemed eligible for endovascular thrombectomy (EVT) are transferred from the emergency room to the angiography suite to undergo the procedure. Recently, the strategy of direct transfer of patients with suspected LVO to the angiography suite (DTAS) has been shown to improve functional outcomes. This study aims to evaluate the cost-effectiveness of the DTAS strategy vs initial transfer of patients with suspected LVO (Rapid Arterial Occlusion Evaluation score >4 and NIH Stroke Scale >10) to the emergency room (ITER). METHODS: A decision-analytic Markov model was developed to estimate the cost-effectiveness of the DTAS strategy vs the ITER strategy from a Dutch health care perspective with a 10-year time horizon. The primary outcome was the incremental cost-effectiveness ratio (ICER) using Dutch thresholds of $59,135 (€50,000) and $94,616 (€80,000) per quality-adjusted life year (QALY). Uncertainty of input parameters was assessed using 1-way sensitivity analysis, scenario analysis, and probabilistic sensitivity analysis. RESULTS: The DTAS strategy yielded 0.65 additional QALYs at an additional $16,089, resulting in an ICER of $24,925/QALY compared with the ITER strategy. The ICER varied from $27,169 to $38,325/QALY across different scenarios. The probabilistic sensitivity analysis showed that the DTAS strategy had a 91.8% and 97.0% likelihood of being cost-effective at a decision threshold of $59,135/QALY and $94,616/QALY, respectively. DISCUSSION: The cost-effectiveness of the DTAS strategy over ITER is robust for patients with suspected LVO. Together with recently published clinical results, this means that implementation of the DTAS strategy may be considered to improve the workflow and outcome of EVT.

Diagnostic Yield of ECG-Gated Cardiac CT in theAcute Phase of Ischemic Stroke vsTransthoracic Echocardiography.

BACKGROUND AND OBJECTIVES: Guidelines recommend echocardiography to screen for structural sources of cardioembolism in patients with ischemic stroke. Cardiac CT is a promising alternative as a first-line screening method. We aimed to determine whether cardiac CT, acquired during the initial stroke imaging protocol, has a higher yield for detecting high-risk cardioaortic sources of embolism than transthoracic echocardiography (TTE). METHODS: We performed a prospective, single-center, observational cohort study and included consecutive adult patients with acute ischemic stroke who underwent ECG-gated cardiac CT during the initial stroke imaging protocol. Patients also underwent the routine stroke workup, including TTE. The main outcome was the proportion of patients with a predefined high-risk cardioaortic source of embolism on cardiac CT vs TTE in patients undergoing both investigations. RESULTS: Between May 2018 and November 2020, 774 patients with a suspected ischemic stroke underwent hyperacute cardiac CT. We excluded 228 patients with a diagnosis other than ischemic stroke and 94 because they did not provide informed consent. Therefore, 452 patients (59.3% male, median age 72) were included. The median additional scan time of cardiac CT was 6 (interquartile range 5-7) minutes with poor scan quality in only 3%. In total, 350 of the 452 patients (77.4%) underwent TTE, 99 of whom were performed in an outpatient setting. Reasons for not undergoing TTE were death (33, 7.3%) and TTE being too burdensome to perform in the outpatient setting (69, 15.3%). A high-risk cardioaortic source of embolism was detected in 40 of the 350 patients (11.4%) on CT, compared with 17 of the 350 (4.9%) on TTE (odds ratio 5.60, 95% CI 2.28-16.33). Cardiac thrombus was the most frequent finding (7.1% vs 0.6%). The diagnostic yield of cardiac CT in the full study population was 55 of the 452 (12.2%). Among the 175 patients with cryptogenic stroke after the routine workup, cardiac CT identified a cause of the stroke in 11 (6.3%). DISCUSSION: Cardiac CT acquired in the acute phase of ischemic stroke is technically feasible and has a superior diagnostic yield compared with TTE for the detection of high-risk sources of embolism. Cardiac CT may be considered as an alternative to TTE to screen for cardioembolism.

Tranexamic Acid After Aneurysmal Subarachnoid Hemorrhage: Post-Hoc Analysis of the ULTRA Trial.

BACKGROUND AND OBJECTIVES: The ULTRA-trial showed that ultra-early and short-term tranexamic acid treatment after subarachnoid hemorrhage did not improve clinical outcome at six months. An expected proportion of the included patients had non-aneurysmal subarachnoid hemorrhage In this post-hoc study, we will investigate whether ultra-early and short-term tranexamic acid treatment in patients with aneurysmal subarachnoid hemorrhage improves clinical outcome at six months. METHODS: The ULTRA-trial is a multicenter, prospective, randomized, controlled, open-label trial with blinded outcome assessment, conducted between July 24, 2013 and January 20, 2020. After confirmation of subarachnoid hemorrhage on non-contrast computer tomography, patients were allocated to either ultra-early and short-term tranexamic acid treatment with usual care, or usual care only. In this post-hoc analysis, we included all ULTRA-participants with a confirmed aneurysm on CT angiography and/or digital subtraction angiography. The primary endpoint was clinical outcome at six months, assessed by the modified Rankin Scale, dichotomized into good (0-3) and poor (4-6) outcome. RESULTS: Of the 813 ULTRA-trial patients who had an aneurysmal subarachnoid hemorrhage, 409 (50%) were assigned to the tranexamic acid group and 404 (50%) to the control group. In the intention-to-treat analysis, 233 of 405 (58%) patients in the tranexamic acid group and 238 of 399 (60%) patients in the control group had a good clinical outcome (adjusted odds ratio (aOR) 0·92; 95% confidence interval (C.I.) 0·69 to 1·24). None of the secondary outcomes showed significant differences between the treatment groups: excellent clinical outcome (mRS 0-2) aOR 0.76, 95% C.I. 0.57-1.03, all-cause mortality at 30 days aOR 0.91, 95% C.I. 0.65-1.28), all-cause mortality at six months aOR 1.10 (95% C.I. 0.80-1.52). DISCUSSION: Ultra-early and short-term tranexamic acid treatment did not improve clinical outcome at six months in patients with aneurysmal subarachnoid hemorrhage and therefore, cannot be recommended. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02684812; submission date February 18, 2016, first patient enrollment on July 24th, 2013). CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that tranexamic acid does not improve outcomes in patients presenting with aneurysmal subarachnoid hemorrhage.