Trials’ results shed light on new technology for preventing stroke, best practices and devices for LVO retrieval, the effectiveness of antiplatelet therapy with the addition of cilostazol and mechanical thrombectomy in pediatric patients with LVO

abstract images of a pulse

Investigators in five trials revealed strategies to reduce the risk of stroke and improve mechanical thrombectomy during the Closing Main Event of #ISC22. Investigators in five trials revealed strategies to reduce the risk of stroke and improve mechanical thrombectomy during the Closing Main Event of #ISC22. They found:

  • Novel Doppler transcranial technological advances improves diagnosis of right to left shunt.
  • EmboTrap®, a mechanical thrombectomy device, resulted in good to ideal outcomes on first pass in the majority of patients with large vessel occlusion (LVO).
  • Antiplatelet therapy with the addition of cilostazol significantly reduced the recurrence of ischemic stroke in male patients without increasing the bleeding risk.
  • Mechanical thrombectomy can be safe and effective for pediatric patients with LVO.
  • Stent retriever (SR) Classic compared favorably to stent retriever plus aspiration catheter and direct aspiration for mechanical thrombectomy success. 

Autonomous robotic transcranial Doppler technology improved right to left shunt detection

Autonomous robotic-assisted transcranial Doppler (raTCD), a novel technological TCD advancement that is not operator dependent, safely improves detection of right to left shunt (RLS), including patent foramen ovale (PFO), compared to current standard of care, according to Novel Robotic-Assisted Transcranial Doppler Versus Transthoracic Echocardiography to Detect Right-to-Left Shunts: the BUBL study.  The multicenter, prospective, single-arm, nonsignificant risk, consecutively enrolled, diagnostic accuracy device study evaluated 129 men and women with embolic stroke or TIA. Patients received a standard of care workup, including transthoracic echocardiography (TTE) and raTCD. The primary endpoint, RLS detection rate, was 63.6% with raTCD (82 patients) and 20.9% with TTE (27 patients), for a difference of 42.6% (p <0.001). There were no serious device-related adverse events.         

“Autonomous robotic-assisted transcranial doppler was substantially more likely to diagnose right-to-left shunt than transthoracic echocardiography,” said Mark Rubin, MD, assistant professor of neurology and medical director of neurosonology at the University of Tennessee Health Science Center in Memphis, the study’s principal investigator. Autonomous robotic-assisted transcranial Doppler accurately detected nearly three times the number of shunts compared to transthoracic echocardiography. “Autonomous robotic-assisted transcranial Doppler was safe and technically feasible for use by health professionals with no transcranial Doppler skills,” Dr. Rubin said.” It may allow providers to achieve the known sensitivity of transcranial Doppler for right-to-left shunt detection without the need for scarce experienced operators.”  

Registry results show rates of mechanical thrombectomy success in a real-world setting

The clinical outcome of EmboTrap®, a mechanical thrombectomy device, was good to ideal in nearly half of patients, with the majority detected on first pass, according to Embotrap® eXtraction & Clot EvaLuation & Lesion Evaluation for NeuroThrombectomy, or EXCELLENT trial.

The prospective, international, multicenter observational registry enrolled patients at 36 international sites, with 25 sites having the capacity to obtain clot immunohistological analysis.  From September 2018 to July 2021, 543 study participants contributed to the combined clot composition analysis. Patients were eligible to participate if EmboTrap® was used in the initial clot retrieval attempt according to practices within the clinical settings. Each center collected procedural, imaging and clinical data.  The researchers utilized an imaging core lab, and central clot labs blinded to the clinical data. In the analysis, site modified treatment in cerebral infarction (mTICI) values were used in 161 clot and 131 non-clot participants, pending final database lock in Dec 2021. Clots were considered red blood cell (RBC)-rich (>45% RBC) or RBC-poor (£45% RBC), with the two groups further subdivided based on fibrin and platelet platelet content.         

“The large multicenter all-comer cohort reflects the population undergoing thrombectomy today in a real-world setting,” said Raul Nogueira, MD, director of the UPMC Stroke Institute and professor of neurology at the University of Pittsburgh School of Medicine, the principal investigator. Overall, 46.8% of patients achieved a good to ideal clinical outcome with EmboTrap®. The procedure is highly effective, with a median number on first pass.

“Clots rich in red blood cells show differences in outcomes when subdivided by platelet content. When analyzed individually, platelet content seems to be at least as strong a predictor of clinical outcome and mortality as fibrin content,” Dr. Nogueira said.

Antiplatelet therapy with the addition of cilostazol may be effective in preventing ischemic stroke recurrence in male patients

In the multicenter, open-label, parallel group trial of Sex Difference in the Impact of Dual Antiplatelet therapy Using Cilostazol for Secondary Stroke Prevention: Sub-analysis of trial, participants (1,320 male and 559 female non-cardiogenic stroke patients) were randomized to either a dual antiplatelet treatment group (aspirin or clopidogrel plus cilostazol) or a monotherapy group (aspirin or clopidogrel).  The drug cilostazol has been identified to have antiplatelet properties. Study findings reveal the dual antiplatelet treatment was more effective in males compared to female patients.             

In this sex-specific sub-analysis of, “Dual antiplatelet therapy using cilostazol significantly reduced the recurrence of ischemic stroke in male patients without increasing bleeding risk. However, significant efficacy was not observed in female patients,” said Haruhiko Hoshino, MD, hospital deputy director and director of the Stroke Center at Tokyo Saiseikai Central Hospital in Japan, the study’s lead investigator. Further investigation is needed to determine whether this sex difference is due to potential differences in the drug, cilostazol, differences in clinical background, or differences in the effects of antiplatelet agents.”

Mechanical thrombectomy improved outcomes in pediatric patients with large vessel occlusion (LVO)

Outcomes in pediatric patients with stroke with large vessel occlusion (LVO) without thrombectomy were significantly worse than in LVO patients with thrombectomy, according to “Pediatric Large Vessel Occlusion Stroke: Poor Outcomes Without Intervention.”  The multicenter retrospective cohort study analyzed pediatric arterial ischemic stroke hospital admission data and LVO in patients 1 month to <17 years of age between 2010-2019 throughout New South Wales, Australia. The primary outcome was pediatric modified Rankin Scale (ped-mRS) score three months after stroke, using ordinal logistic regression to compared non-LVO, LVO without thrombectomy and LVO with thrombectomy groups.  Of 166 total pediatric arterial stroke admissions, 39 (23.5%) had LVO, of which 13 received thrombectomy and 26 did not. LVO pediatric patients without thrombectomy had significantly worse clinical outcomes than non-LVO pediatric stroke patients at three months (OR 3.64; p=0.001). Long-term outcomes in LVO patients without thrombectomy were also significantly worse than LVO with thrombectomy (OR 6.07; p=0.010). The majority of LVO patients presented within time windows suitable for thrombectomy; 82% met adult selection criteria for thrombectomy.  “With such poor outcomes, we should strongly consider thrombectomy for kids,” said Kartik Bhatia, MD, an interventional neuroradiologist with the Sydney Children’s Hospital Network, the study’s lead investigator. “We should make greater efforts to triage and image children with LVO earlier and strengthen existing stroke treatment guidelines in children.”

Mechanical thrombectomy device techniques compared in patients with LVO

The procedural success and clinical outcomes of mechanical thrombectomy with stent retriever (SR) Classic for first pass patients with large vessel occlusion (LVO) was favored when compared to SR Combination (stent retriever plus aspiration) or Direct Aspiration, according to Outcomes of Efficiency Techniques During Mechanical Thrombectomy in Acute Ischemic Stroke Assist Global Registry Analysis, the ASSIST Registry.         

The global, multicenter, prospective, consecutive trial enrolled 1,300 patients experiencing acute ischemic stroke in 71 sites from 2019 to 2022, clustered by primary mechanical thrombectomy technique: SR Classic, SR Combination or Direct Aspiration.  Severity of disability at day 90 was assessed by modified Rankin Scale (mRS) with a good functional outcome defined by mRS score of 0-2 above 50% for each technique. The safety profile of these interventional techniques were similar as well.

“Of the three cohorts, the SR Classic technique had a significantly higher rate of first pass treatment for cerebral infarction (TICI) 3 compared to SR Combination or Direct Aspiration,” said David S. Liebeskind, MD, director of the UCLA Stroke Center.  Dr. Liebeskind noted that the combination therapy takes longer to achieve reperfusion, which can be attributed to the lengthier set up required when utilizing more devices. Patients treated with direct aspiration required significantly more passes compared to SR Combination or SR Classic. In a further analysis, 200 additional subjects treated with large bore aspiration catheter will be completed. “Stay tuned,” Dr. Liebeskind said.