Influential Factors And Predictive Models Of Poor Outcome In Acute Anterior Circulation Stroke Undergoing Mechanical Thrombectomy

Background and purpose: Five prospective randomized controlled studies have consistently shown that mechanical thrombectomy is better than standard drug therapy.However,there were still some patients with poor outcome despite receiving mechanical thrombectomy.Risk factors for poor clinical prognosis are increasingly received attention.Elevated mean platelet volume(MPV),indicating higher platelet activity,could be a predictor of prognosis in patients with acute ischemic stroke receiving medical therapy alone.Our aim was to investigate the relationship between MPV and functional outcome in acute anterior circulation stroke undergoing mechanical thrombectomy after 3 months.Moreover,the study aimed also to evaluate the power of Pittsburgh response to endovascular therapy(PRE)score and Houston Intra-Arterial Therapy-2(HIAT-2)in predicting poor outcome for patients with large vessel occlusion stroke treated with mechanical thrombectomy after 3 months.Methods: A total of 153 consecutive patients with acute stroke following mechanical thrombectomy were enrolled from May 2013 to March 2016 in two separate stroke centers.Subjects were divided into two groups according to average MPV level.Univariate and multivariate analyses were performed.A receiver operating characteristic(ROC)curve was used to evaluate the possibility of MPV value to predict unfavorable outcome.In addition,ROC area under the curve(AUC)was also used to determine the predictive power of PRE and HIAT-2 scores to predict poor outcome and death within 3 months after procedure.Results: The average MPV was 10.4 fL.Patients with high MPV had a significant lower rate of functional independence(28.9% VS 57.1%,p=0.000).After multivariable analysis,elevated MPV(?10.4fL)remained an independent predictor of unfavorable outcome(OR=3.93,95% CI 1.73-8.94,P=0.001).When the MPV cut-off value was set to 10.4 fL using the ROC analysis,MPV predicted unfavorable outcome with 62.1% sensitivity and 66.7% specificity,respectively.Besides,older(OR=1.05,95% CI 1.01-1.09,P=0.012)and increased baseline NIHSS(OR=1.19,95% CI 1.09-1.31,P=0.000)were also independent indicator of poor outcome within 3 months following mechanical thrombectomy.PRE(AUC=0.76,95% CI 0.69-0.84,P=0.000)and HIAT-2(AUC=0.78,95%CI 0.71-0.86,P=0.000)scores had moderate predictive accuracy of poor functional outcome at 3 months after the procedure,there were no statistical difference between PRE and HIAT-2 scores(Z=0.38,P=0.704).Likewise,PRE(AUC=0.73,95% CI 0.64-0.82,P=0.000)and HIAT-2(AUC=0.70,95% CI 0.61-0.79,P=0.000)scores had also moderate predictive ability of death at 3 months after mechanical thrombectomy,there were also no statistical difference between PRE and HIAT-2 scores(Z=0.38,P=0.704).Conclusions: Elevated MPV(?10.4fL)was an independent predictor of poor outcome in patients with acute anterior circulation stroke undergoing mechanical thrombectomy at 3 months.Additionally,older and increased initial NIHSS were also independently associated with poor outcome at 3 months treated with mechanical thrombectomy.PRE and HIAT-2 scores showed moderate discriminative value of poor outcome and death in patients with acute occlusion of anterior circulation undergoing mechanical thrombectomy at 3 months.