TREVO 2 adds momentum to mechanical intervention for stroke
medwireNews: Patients with large vessel occlusion stroke are more likely to achieve reperfusion if treated with the Trevo retriever than with the Merci retriever, say the TREVO 2 investigators.
The Trevo is the second device, after the Solitarie retriever (SWIFT trial), to report improved results in a head-to-head comparison with the Merci retriever, which is approved by the US Food and Drug Administration. The SWIFT findings were reported at the International Stroke Conference earlier this year, and have now been published in The Lancet, along with those of TREVO 2.
In a commentary accompanying the two papers, Philip Gorelick (Michigan State University College of Human Medicine, Grand Rapids, USA) says: "The SWIFT and TREVO 2 studies, although modest in sample size, begin to answer the call for high-level evidence about the efficacy and safety of mechanical clot retrieval devices in acute ischaemic stroke.
"It will be interesting to learn, on the basis of future non-primary analyses, whether collateral flow patterns or clot characteristics elucidate propensity for treatment response."
In TREVO 2, 86% of 88 patients treated with the Trevo retriever achieved reperfusion, defined as a thrombolysis in cerebral infarction (TICI) score of 2 or more. By comparison, 60% of 90 patients treated with the Merci retriever achieved this outcome, which was a significant difference.
TICI scores were determined by a central core laboratory, rather than by local investigators. Gorelick stresses the importance of this, noting that local investigators in SWIFT overestimated recanalization rates with both devices, while the TREVO 2 core laboratory found an increase in the frequency of vessel perforation with the Merci retriever relative to that reported by local researchers in previous studies.
The primary safety endpoint, which was a composite of procedural-related outcomes including symptomatic intracranial hemorrhage, occurred in 15% and 23% of the Trevo and Merci groups, respectively, which was not a significant difference.
There has previously been doubt over whether the effective recanalization provided by mechanical clot retrieval actually results in improved patient outcomes.
TREVO 2, in line with the SWIFT findings, shows that patients have better 3-month outcomes when treated with the newer device rather than the Merci retriever; 40% of the former versus 22% of the latter group had good 90-day functional outcomes (modified Rankin Scale 0-2). This was equivalent to a significant 2.4-fold increase in the likelihood for a good outcome.
However, Gorelick notes that future trials of the devices should compare them with thrombolytic therapy, including the newer therapies such as tenecteplase.
medwireNews (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Eleanor McDermid, Senior medwireNews Reporter