Reperfusion injury in the age of revascularization

Now that the door is open: an update on ischemic stroke pharmacotherapeutics for the neurointerventionalist

The last 10 years have seen a major shift in management of large vessel ischemic stroke with changes towards ever-expanding use of reperfusion therapies (intravenous thrombolysis and mechanical thrombectomy). These strategies 'open the door' to acute therapeutics for ischemic tissue, and we should investigate novel therapeutic approaches to enhance survival of recently reperfused brain. Key insights into new approaches have been provided through translational research models and preclinical paradigms, and through detailed research on ischemic mechanisms. Additional recent clinical trials offer exciting salvos into this new strategy of pairing reperfusion with neuroprotective therapy. This pairing strategy can be employed using drugs that have shown neuroprotective efficacy; neurointerventionalists can administer these during or immediately after reperfusion therapy. This represents a crucial moment when we emphasize reperfusion, and have the technological capability along with the clinical trial experience to lead the way in multiprong approaches to stroke treatment.

Predicting Futile Recanalization in Acute Ischemic Stroke Patients Undergoing Endovascular Thrombectomy: The Role of White Blood Cell Count to Mean Platelet Volume Ratio

BACKGROUND

Approximately half of AIS patients have an unfavorable outcome even after complete reperfusion. White blood cell (WBC) count to mean platelet volume (MPV) ratio (WMR) may be a promising predictive factor for futile recanalization. This study aimed to determine the predictive value of WMR in identifying individuals at higher risk of futile recanalization.

METHODS

In this retrospective cohort study, 296 patients who achieved complete reperfusion after endovascular treatment (EVT) were included in the analysis. WBC count and MPV were collected at admission. Multivariable logistic regression was used to examine the independent association of the WMR with functional outcomes at three months. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) analyses were used to compare the accuracy of WMR for predicting futile recanalization.

RESULTS

The adjusted odds ratios for the fourth quartile of WMR were 3.142 (95% CI 1.405- 7.027, P = 0.005) for unfavorable outcomes at 3 months in comparison with the first quartile. The inclusion of WMR in the traditional model enabled a more accurate prediction of unfavorable outcomes (NRI 0.250, P = 0.031; IDI 0.022, P = 0.017).

CONCLUSION

Elevated WMR at admission was independently associated with futile recanalization among AIS patients who received EVT and might be useful in identifying futile recanalization.

Multiphase adjuvant neuroprotection: A novel paradigm for improving acute ischemic stroke outcomes

While several large pivotal clinical trials recently revealed a substantial benefit of endovascular thrombectomy for acute ischemic stroke (AIS) caused by large-vessel occlusion, many patients still experience mediocre prognosis. Enlargement of the ischemic core, failed revascularization, incomplete reperfusion, distal embolization, and secondary reperfusion injury substantially impact the salvaging of brain tissue and the functional outcomes of AIS. Here, we propose novel concept of “Multiphase Adjuvant Neuroprotection” as a new paradigm that may help guide our search for adjunctive treatments to be used together with thrombectomy. The premise of multiphase adjuvant neuroprotection is based on the diverse and potentially nonoverlapping pathophysiologic mechanisms that are triggered before, during, and after thrombectomy therapies. Before thrombectomy, strategies should focus on preventing the growth of the ischemic core; during thrombectomy, improving recanalization while reducing distal embolization and maximizing reperfusion are of significant importance; after reperfusion, strategies should focus on seeking targets to reduce secondary reperfusion injury. The concept of multiphase adjuvant neuroprotection, wherein different strategies are employed throughout the various phases of clinical care, might provide a paradigm to minimize the final infarct size and improve functional outcome in AIS patients treated with thrombectomy. With the success of thrombectomy in selected AIS patients, there is now an opportunity to revisit stroke neuroprotection. Notably, if the underlying mechanisms of these neuroprotective strategies are identified, their role in the distinct phases will provide further avenues to improve patient outcomes of AIS.