Interventional strategies will prove to be as beneficial for stroke as they have been shown to be for MI, the study authors predict.
Endovascular therapy (EVT) for acute ischemic stroke is associated with better 90-day survival but similar risk of intracranial hemorrhage (ICH) compared with medical therapy alone, according to a meta-analysis of the randomized clinical trials that were cited in the 2018 American Heart Association/American Stroke Association (AHA/ASA) guidelines.
Investigators led by Yingfeng Lin, MD (Heinrich-Heine-University, Düsseldorf, Germany), point out the remarkable similarities in the recent evolution of the management of acute ischemic stroke and MI. In both cases, IV thrombolysis was initially established as the first-line of therapy, only to be superseded by interventional strategies.
A key difference, however, was that studies of IV thrombolysis for stroke did not reveal the mortality benefits that were seen when it was used to treat MI. As a result, randomized trials evaluating EVT for stroke focused on functional recovery and were underpowered to detect differences in mortality.
Lin et al identified 10 randomized controlled trials cited in the AHA/ASA 2018 guidelines for the treatment of acute ischemic stroke that compared EVT with medical therapy. Their results were published online recently in JAMA Neurology,
In the meta-analysis, which comprised 2,313 patients, the use of EVT was associated with a significantly reduced risk of mortality at 90 days (RR 0.81; 95% CI 0.68-0.98). There was also a trend toward lower 90-day mortality when breaking down patients by those included in trials early time window interventions (RR 0.83; 95% CI 0.67-1.01) and late time window interventions (RR 0.76; 95% CI 0.41-1.40). There was no difference in the risk of ICH (RR 1.11; 95% CI 0.71-1.72).
“Thus, the observed risk reduction for mortality probably does not originate from differences in adverse effects but [instead] from the functional benefits of EVT also translating to improved 90-day survival,” Lin and colleagues write.
They add that the meta-analysis features “the largest number of analyzed patients and events, to our knowledge, and achieves sufficient power to reach statistical significance.”
Lin et al say the results should be interpreted with “considerable caution” due to limitations such as trial heterogeneity in the study protocols and among EVT devices and modalities, as well as the risk of bias from analysis of secondary trial endpoints and incomplete recruitment in some trials that were terminated prematurely. “However, new EVT trials designed to show mortality differences in [acute ischemic stroke] might never be performed; thus, a meta-analysis of available data may be the only way to analyze short-term survival,” according to the authors.
Taken together, the evidence suggests that there is considerable evidence of the survival benefit of EVT from the guideline-referenced RCTs, Lin and colleagues conclude. “We cannot help but see the parallels: endovascular strategies may well turn out to be as successful in [acute ischemic stroke] as in myocardial infarction.”
Source:
Lin Y, Schulze V, Brockmeyer M, et al. Endovascular thrombectomy as a means to improve survival in acute ischemic stroke: a meta-analysis. JAMA Neurol. 2019;Epub ahead of print.
Disclosures:
Lin reports no relevant conflicts of interest.