tPA Before Stroke Intervention: Perfusion 'Almost Never Complete'

No idea what we should be talking to our stroke doctors about on this news. tPA has been known to be a failure at complete recovery since it was approved in 1996, tPA at 12% full effectiveness.
https://www.medpagetoday.com/cardiology/pci/73970? 

Angiographic success often still followed by endovascular tx

• by Nicole Lou, Reporter, MedPage Today/CRTonline.org July 11, 2018

Thrombolytics given before endovascular therapy rarely open up the occlusion enough to obviate the procedure, according to a study of stroke patients at a comprehensive stroke center in Switzerland.

Reperfusion with tissue-type plasminogen activator (tPA) alone was complete -- Thrombolysis in Cerebral Infarction (TICI) grade 3 perfusion -- in only one such case out of 627, Urs Fischer, MD, MSc, of Switzerland's University of Bern, Inselspital, and colleagues, reported online in Stroke

.

Overall, 10.7% of patients who got angiography with an intention to perform endovascular therapy had a change of occlusion site. These changes reached:

• TICI 0/1 perfusion in 2.7%
• TICI ≥2a in 6.2%
• TICI ≥2b in 2.9%

However, 51.3% of those who reached TICI 2a or better with tPA alone still got subsequent endovascular therapy in the form of stent retriever-based thrombectomy, intra-arterial thrombolysis, or both.

Those who reached TICI 2a reperfusion with lytic bridging before endovascular treatment trended, albeit nonsignificantly, towards more favorable outcomes (modified Rankin Scale score 2 and below, adjusted OR 2.65, 95% CI 0.98-7.17). However, final reperfusion success was less often a complete TICI 3 in patients with pre-interventional changes at the occlusion site than in peers without (17.9% versus 41.8%, P<0.001).

Significant predictors of perfusion reaching TICI 2a or better were:

• IV tPA: adjusted OR 11.98
• Cardiogenic thrombus origin: adjusted OR 2.3
• Thrombus length: adjusted OR 0.926 per 1 mm increase

In the 2.2% of cases where the occlusion was located in the internal carotid artery and proximal M1 segments, perfusion actually worsened with tPA (adjusted OR 4.33, 95% CI 1.12-16.80), perhaps by promoting clot fragmentation, Fischer's group suggested. Overall, perfusion grade worsened in 1.8% of patients with pre-interventional lytics.

"Obviously, intravenous tPA in a drip-and-ship scenario should not be withheld or delayed, because reperfusion, if achieved, may occur decisively earlier than with subsequent ET [endovascular therapy]," they wrote. "In contrast, in patients admitted directly to a comprehensive stroke center with access to ET, the value of pre-interventional IV tPA to facilitate reperfusion is less clear considering the substantially shorter time intervals."

"Because reperfusion of large vessel occlusion after IV tPA was shown to be time-dependent, reperfusion may not occur early enough, that is, before the start of thrombectomy, and therefore in patients with direct access to endovascular treatment, the prevalence, and extent of pre-interventional reperfusion associated with intravenous tPA deserves further evaluation," they said.

The study of stroke patients with immediate access to endovascular treatment was based on Bernese Stroke registry enrollees who were admitted directly to a comprehensive stroke center (n=627).

Fischer and colleagues pointed out that the non-randomized nature of their study left an inherent possibility of bias for giving tPA to select patients and noted that the decision to pursue endovascular therapy after tPA was left up to individual operators.

The study was supported by the Swiss Stroke Society, the Bangerter Foundation, and the Swiss Academy of Medical Sciences through the "Young Talents in Clinical Research" program.

Fischer disclosed serving as a global PI for Medtronic's SWIFT DIRECT study.

• Primary Source

  Stroke

  Source Reference: Kaesmacher J, et al "Rates and quality of preinterventional reperfusion in patients with direct access to endovascular treatment" Stroke 2018; DOI: 10.1161/STROKEAHA.118.021579.