Advanced Software Allows Later Stroke Treatment

So once again you need to have the perfect stroke to be treated, nothing here about getting patients 100% recovered. That is the only goal, not faster treatment or better results. 100% recovery. GET THERE!

Advanced Software Allows Later Stroke Treatment

December 10, 2018 by srudolph

The treatment of stroke patients has been characterized by the need for speed. The only medical therapy available, a clot dissolving drug called tPA, was originally available for use only if it could be given less than 3 hours after the start of symptoms. This led to the development of stroke centers to treat patients as rapidly as possible. Ten years ago the time was extended to 4.5 hours for some patients.

In recent years, another type of stroke treatment has been developed known as endovascular thrombectomy. In this procedure, a catheter is guided into a brain artery, and a device is used to pull a clot out of the brain. In 2015, this procedure was demonstrated to benefit patients with the most severe strokes, those due to large clots, up to 6 hours after the start of symptoms.

Researchers have been working for years to find a way to identify patients who would benefit from later treatment. These patients, who are suffering a stroke due to a lack of blood flow to the brain, are those who have not yet suffered significant damage. 

A breakthrough advance in the selection of stroke patients for therapy is  software that is able to analyze special CT scan images, known as CT perfusion. This software can automatically determine which patients have a small area of permanent damage, and an area that can be potentially saved by available treatments.

Using one type of software, known as RAPID, it has now been demonstrated in multiple stroke studies performed around the world that some patients may be treated with thrombectomy up to 24 hours. Only during the past month researchers from Australia showed that using this software, some patients can be successfuly treated with tPA (Your definition of success is appalling, I expect success to be 100% recovery. When the hell are you going to deliver that success?)up to 9 hours following the beginning of stroke symptoms.
As this software, and others like it, come into more common use, more stroke patients will be treated later and more effectively.
Thrombectomy is being performed up to 24 hours in many stroke centers, and in the future, the window for tPA is expected to be extended.

When in Doubt, Tool May Help Predict Success of Stroke Thrombectomy

Well shit, you had better hope you have the perfect stroke that matches the ones tested in clinical trials. You wouldn't want to strain the intellectual capacity of your doctor and hospital. They might have to do some additional work and research to figure out how to get everyone 100% recovered.
https://www.medpagetoday.com/CriticalCare/Strokes/65060?xid=nl_mpt_DHE_2017-05-06&eun=g424561d0r&pos=1

Odds of benefit calculated with moderate power

• by Nicole Lou
  Reporter, MedPage Today/CRTonline.org May 05, 2017

Action Points

• A clinical decision tool combining multiple baseline clinical and radiological characteristics appears useful in distinguishing between individual patients who may and may not experience benefit from intra-arterial treatment for acute ischemic stroke.
• Realize that the newly developed clinical decision tool combines multiple characteristics and shows large variations in treatment benefit between patients, so selection of individual patients for intra-arterial treatment should not be based on single patient characteristics.

With the development of a clinical decision-making tool, an individualized approach to deciding which stroke patients should get endovascular therapy may be on its way, researchers reported.
Combining various baseline characteristics, multivariable regression produced a model that showed moderate power upon validation (C statistic 0.73, 95% CI 0.67-0.79) at discriminating which thrombectomy recipients were likely to have a good functional outcome, defined as a modified Rankin Scale (mRS) score from 0 to 2, at 90 days after stroke.
An ordinal model predicting the difference in the odds of a good outcome between stroke therapy with and without intra-arterial treatment had similarly moderate predictive power on external validation (C statistic 0.69, 95% CI 0.64-0.73), according to Esmee Venema, MD, MSc, of Erasmus Medical Center in Rotterdam in the Netherlands, and colleagues in a study published online in the BMJ. Venema's group had their model made available online.
"Mean predicted absolute treatment benefit was an 11.8% higher probability of mRS score 0-2 compared with the probability without intra-arterial treatment, and varied from −2.3% to 24.3% between individual patients in the combined derivation and validation cohort," the authors noted.
Venema and colleagues derived the model from all 500 patients in the Multicenter Randomised Clinical Trial for Acute Ischaemic Stroke in the Netherlands (MR CLEAN), who were all enrolled at 16 Dutch hospitals.
A separate validation cohort consisted of 260 patients from the Interventional Management of Stroke III (IMS III) trial, a group that with proven occlusions in the anterior circulation on non-invasive vessel imaging and an available mRS score. This latter group was enrolled at 58 centers across the U.S., Canada, Australia, and Europe.
"We found modest interaction with treatment for history of ischaemic stroke, collateral score, and time from stroke onset to groin puncture," the investigators wrote. "For collateral score and time to groin puncture, interaction with effect of intra-arterial treatment was already shown in previous subgroup analyses. Both variables are clinically likely to cause an interaction with intra-arterial treatment."
"However, previous stroke has not been studied for interaction with treatment before, and was an unexpected finding in our study," they noted. "It may be a chance finding, since it was not reproduced in the validation cohort and we have no clinical explanation."
As for the actual use of the tool in patients with acute ischemic stroke, Venema and colleagues emphasized that the C statistic of 0.69 for the ordinal outcome was a conservative measure.
"It assesses discrimination between exact categories of the mRS, instead of discrimination between two groups with different outcome (e.g., mRS score 0-2 v mRS score 3-6). Externally validated C statistics of all cut-offs were better than the ordinal C statistic (e.g., 0.73 for good functional outcome and 0.75 for mortality)."
"Nevertheless, the relatively small sample size and inclusion of interaction terms in the model may have resulted in some optimism and overfitting, despite shrinkage of the regression coefficients," they admitted.
In addition, the authors said, their model suffered from poor calibration due to the superior outcomes of patients in the IMS III trial.
"Despite its limitations, the currently developed model is the first to predict the effect of intra-arterial treatment for individual patients on arrival at the emergency department. When compared with other models used in neurovascular practice, HAS-BLED (C statistic 0.65) and CHA₂DS₂-VASc (0.61), it performs accurately," Venema's group maintained.
"More importantly, our study shows that treatment should not be withheld based on one characteristic," they wrote. "Some patients belonging to one of the subgroups that are considered as having no benefit of intra-arterial treatment, such as poor collaterals or low ASPECTS, may still benefit from intra-arterial treatment substantially if other characteristics are favourable. This emphasises the importance of making personalized treatment decisions, instead of using average treatment effects, and shows the need for combining multiple clinical and radiological baseline characteristics instead of withholding treatment based on one characteristic."

The study was funded by Erasmus MC Cost-Effectiveness Research.
Venema disclosed no conflicts of interest.
Co-authors reported relationships with Genentech, EKOS Corporation, Concentric Medical, Cordis, Penumbra, UpToDate, Grand Rounds, St. Jude Medical, Biogen, DEKRA, Novartis, Stryker, and Codman.

• Reviewed by Henry A. Solomon, MD, FACP, FACC Clinical Associate Professor, Weill Cornell Medical College and Dorothy Caputo, MA, BSN, RN, Nurse Planner

• Primary Source

  BMJ

  Source Reference: Venema E, et al "Selection of patients for intra-arterial treatment for acute ischaemic stroke: development and validation of a clinical decision tool in two randomised trials" BMJ 2017; DOI: 10.1136/bmj.j1710.