Intravenous Thrombolysis Procedure Improvement And Collateral Assessment In Acute Ischemic Stroke Patients

Part Ⅰ Intravenous Thrombolysis Procedure Improvement in Acute Ischemic Stroke Patients:Is it Necessary to Wait for Platelet Count and Coagulation Results before Intravenous Thrombolysis in Acute Ischemic Stroke?Objectives To assess the incidence of thrombocytopenia and abnormal coagulation in ischemic stroke patients, and time gained and outcome after thrombolysis by initiating intravenous thrombolysis treatment prior to availability of platelet (PLT) and coagulation results.Methods Consecutive acute ischemic stroke (AIS) or transient ischemic attack (TIA) patients within 12 hours of symptom onset who were admitted from January 2009 to December 2013 were retrospectively recruited. First laboratory reports in their medical charts were collected. Consecutive AIS patients who received intravenous thrombolysis at Huashan Hospital from Jan 2009 to Dec 2013 were retrospectively recruited. The thrombolytic procedures were further optimized since Jun 2012. With patients’ consent, intravenous thrombolysis therapy was initiated without PLT and coagulation results after certain previous history and medications were ruled out. Patients treated with intravenous thrombolysis were divided into two groups according to initiation of thrombolysis before or after PLT and coagulation results. Baseline demographic data, symptomatic intracerebral haemorrhage (sICH) rates, mortality on the 7th day as well as functional outcome at 3 month were collected. Door-to-needle time (DNT) as well as efficacy and safety of thrombolysis therapy were compared between the two groups.Results Of 419 AIS patients within 12 hours of symptom onset,12 had thrombocytopenia or abnormal coagulation. From Jan 2009 to Dec 2013,178 cases of thrombolysis patients were recruited. Waiting for coagulation results would have prolonged door-to-needle time (P<0.001, U=2237.000), which was 90min. Otherwise, median of DNT was 59min. There was no statistical significance in the rate of sICH, early efficacy,7d mortality and 3-month good outcome in two groups.(p=0.936,0.198, 0.211,0.663)Conclusions The incidence of thrombocytopenia and abnormal coagulation is rare in AIS patients. Initiating intravenous thrombolysis treatment prior to availability of coagulation results, associated with other measures, can significantly shorten DNT and would not increase the risk of sICH and 7d mortality.Part II Collateral Assessment based on Computed Tomography Perfusion Source Image in Acute Ischemic Stroke Patients and Renal Safety after Multimodal CT ScanObjectives The importance of leptomeningeal collateral flow (LMF) in the outcome after acute ischemic stroke is highly recognized. We described a novel method-Huashan collateral assessment score (HSCAS) on computed tomography perfusion source image (CTP-SI) to assess LMFs and hypothesized that HSCAS would be associated with the clinical outcome in acute stroke patients with middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion. Further more, safety of renal function and thrombolysis therapy after CT perfusion and CT angiography in acute ischemic stroke patients need to be evaluated.Methods We analyzed consecutive MCA/ICA occlusion patients within 12h of stroke symptom onset received multimodal CT prior to treatment from Dec 2011 to Jan 2014. CTP-SI was used to identify the HSCAS between the normal MCA Sylvian branches and those in the affected hemisphere. HSCAS was scored by 7 grades. Maximum intensity projection (MIP) images of CTA were reconstructed to assess the MCA reconstitution score (MCARs), collateral score (CS) and regional leptomeningeal collateral score (rLMCs) by two experienced observers. We compare the reliability of our method with the other three populate CTA based collateral assessment methods. Adverse clinical outcome was defined as mRS≥ 2 at 90 days. To assess the safety of renal function and thrombolysis therapy in acute ischemic stroke patients after multimodal CT scan, consecutive thrombolysis patients from Jan 2009 to Dec 2013 were recuited. We calculated the sex-specific, weight-dependent creatinine clearance (CCr) by use of the Cockgroft-Gault equation. Inclusion criteria were as follows:(1) baseline and an available early (≤72h) follow-up creatinine results, and(2) baseline CCr≥30ml/min. Patients were divided into two groups according to whether they received multimodal CT scan or not to assess the incidence of contrast-induced nephropathy (CIN). We also compare creatinine increase cases, rate of sICH, early efficacy,7d mortality and 3-month good outcome between the two groups.Results There were thirty-eight patients (73.7% male, median NIHSS 12.5) admitted to our hospital within 12h since the symptom onset. The interraters agreements of CS, rLMC grade score, MCARs and HSCAS between two observers were 0.662,0.790, 0.705 and 0.825 respectively. Higher HSCAS was correlated with lower rLMCs and CS. (p< 0.001,p< 0.001) Significant different median HSCAS were found among grades of MCARs and rLMCs. (p<0.001,p=0.002) Increased HSCAS was associated with 90-day mRS (2-6) with area under curve of 0.759 (95%CI 0.607-0.910, p=0.008) in ROC analysis. From Jan 2009 to Dec 2012, there were 99 intravenous thrombolysis patients with a baseline CCr ≥30ml/min, and the baseline and an early (≤72h) follow-up creatinine results were available. Among these patients, there were 51 cases in the target group (the multimodal CT scan group). According to the baseline CCr results,83 patients were admitted with normal CCr. Baseline data were similar between the target group and control group. Only 2/51 (3.9%) patients developed CIN in the target group. No matter the baseline CCr was normal or not, multimodal CT scan was not associated with creatinine shift. There was no statistical significance in the rate of sICH, early efficacy,7d mortality and 3-month good outcome between the target group and the control group. (p=0.396,0.270,0.543,0.196)Conclusions The HSCAS is a reliable method to assess LMFs in acute MCA/ICA occlusion stroke patients. Higher HSCAS is associated with adverse functional outcome independently. There is a low incidence of CIN in intravenous thrombolysis patients undergoing emergency multimodal CT scan. Contrast agents given for multimodal CT performed in patients with normal and abnormal creatinine level, neither caused renal injury nor interfered with the efficacy and safety of rtPA treatment.