麻豆传媒

Successful reperfusion is better defined as Modified Thrombolysis in Cerebral Infarction (mTICI) 2C and 3 at the end of thrombectomy, a group of French researchers argued.

Stroke survivors were equally likely to have a favorable outcome -- a modified Rankin Scale (mRS) score 0 to 2 at 90 days -- whether they were left with mTICI 2B-, 2C-, or 3-grade reperfusion at the end of the procedure (42.9% versus 56.7% versus 56.7%, P>0.05).

However, grades 2C and 3 together held an advantage over the 2B group (OR 1.72, 95% CI 1.01-2.90). This difference persisted after adjustment, Cyril Dargazanli, MD, MSc, of Hôpital Gui de Chauliac in Montpellier, France, and colleagues reported online in .

"Combining mTICI 2C and TICI 3 grades helps to determine a subgroup of patients who achieve better functional outcomes than mTICI 2B patients," the investigators concluded. "Achieving mTICI 2C/3 reperfusion should be the new aim of mechanical thrombectomy for anterior circulation large vessel occlusion."

Gregory Albers, MD, of California's Stanford University Medical Center, commented to 麻豆传媒 that he agreed with this, having also observed in the DEFUSE 3 trial better outcomes the closer to perfect that reperfusion gets.

Logistically speaking, it's not that big a change for operators or clinical trialists to redefine successful reperfusion as mTICI 2C and 3, he said. "However, it is not always possible to achieve at 2C-3 and it is very important not to do additional interventions that place the patient at risk for complications," he cautioned.

Patients included in the study were enrolled in the randomized Contact Aspiration Versus Stent Retriever for Successful Revascularization (ASTER) trial designed to compare the mechanical thrombectomy strategies of contact aspiration and stent retriever therapy across eight high-volume stroke centers in France.

Of the 381 trial participants -- all presenting with suspected ischemic stroke secondary to occlusion of the anterior circulation within 6 hours of onset of symptoms -- 290 were included in the analysis because they had mTICI 2B (30.7%), mTICI 2C (21.4%), or mTICI 3 (47.9%) reperfusion.

Use of IV thrombolysis treatment was allowed in ASTER. An external core laboratory provided angiographic outcome adjudication.

The overall distribution of mRS scores did not not significantly favor the higher mTICI grades, Dargazanli's group reported.

Nonetheless, neurological improvement (defined as an NIH Stroke Scale score of 0 to 1) at 24 hours was significantly more likely for the mTICI 2C and 3 groups than 2B (65.5% and 60.2% versus 39.8%, adjusted OR 2.27, 95% CI 1.26-4.08). Moreover, these patients showed a bigger improvement in NIH Stroke Scale at 24 hours (8.4 and 7.0 versus 3.5 points, adjusted OR 3.4, 95% CI 1.4-5.4).

Of note, the near-complete reperfusion achieved when mTICI 2C and 3 were reached was associated with lower 90-day all-cause mortality (8.3% and 14.2% versus 23.8% for mTICI 2B, adjusted OR 0.37, 95% CI 0.16-0.83) -- although this lost statistical significance upon further adjustment for procedure-related adverse events and parenchymal hematoma (adjusted OR 0.53, 95% CI 0.22-1.26).

There was no interaction between mTICI 2B-3 reperfusion and onset-to-reperfusion time on favorable outcome, overall mRS distribution, early neurological improvement, 24-hour change in NIH Stroke Scale, and mortality.

One limitation of their approach, the authors acknowledged, is that mTICI 2C reperfusion "may be difficult to interpret given the lack of objective parameters such as obvious arterial occlusion."

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