Accuracy of the ABC/2 Score for Intracerebral Hemorrhage: Systematic Review and Analysis of MISTIE, CLEAR-IVH, and CLEAR III

BACKGROUND AND PURPOSE

The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography-based planimetry (CTP).

METHODS

In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression.

RESULTS

In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC (r(2)=0.93) than with site-ABC (r(2)=0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm(3); CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P<0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots.

CONCLUSIONS

ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.

A multicenter, randomized, double-blinded, placebo-controlled phase III study of Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR III)

BACKGROUND

In adults, intraventricular thrombolytic therapy with recombinant tissue plasminogen activator (rtPA) facilitates resolution of intraventricular haemorrhage (IVH), reduces intracranial pressure, decreases duration of cerebrospinal fluid diversion, and may ameliorate direct neural injury. We hypothesize that patients with small parenchymal haematoma volumes (<30 cc) and relatively large IVH causing acute obstructive hydrocephalus would have improved clinical outcomes when given injections of low-dose rtPA to accelerate lysis and evacuation of IVH compared with placebo.

METHODS

The Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage III trial is an investigator-initiated, phase III, randomized, multicenter, double-blind, placebo-controlled study comparing the use of external ventricular drainage (EVD) combined with intraventricular injection of rtPA to EVD plus intraventricular injection of normal saline (placebo) for the treatment of IVH. Patients with known symptom onset within 24 h of the computed tomography scan confirmed IVH and third or fourth ventricle obstruction, with or without supratentorial intracerebral haemorrhage volume <30 cc, who require EVD are screened with a computed tomography scan at least six hours after EVD placement and, if necessary, at consecutive 12-h intervals until stabilization of any intracranial bleeding has been established. Patients who meet clinical and imaging criteria (no ongoing coagulopathy and no suspicion of aneurysm, arteriovenous malformation, or any other vascular anomaly) will be randomized to either intraventricular rtPA or placebo.

RESULTS

The primary outcome measure is dichotomized modified Rankin Scale 0-3 vs. 4-6 at 180 days. Clinical secondary outcomes include additional modified Rankin Scale dichotomizations at 180 days (0-4 vs. 5-6), ordinal modified Rankin Scale (0-6), mortality and safety events at 30 days, mortality at 180 days, functional status measures, type and intensity of intensive care unit management, rate and extent of ventricular blood clot removal, and quality of life measures.

Determinants of effective cooling during endovascular hypothermia

BACKGROUND

Therapeutic hypothermia is a promising neuroprotective therapy with multiple mechanisms of action. We demonstrated the feasibility of thrombolysis combined with endovascular hypothermia, but not all patients achieved effective cooling. We sought to identify the factors that determined effective cooling.

METHODS

In 26 patients who underwent endovascular hypothermia, we computed four measures of effective cooling: time to reach target; Area-Under-the-Curve (AUC) 34 ratio; AUC-34; and AUC-35. By multivariate regression, we examined the effects of age, weight, starting temperature, body mass index, body surface area (BSA), gender, shivering, and total meperidine dose on the four outcome measures.

RESULTS

In univariate analyses, all four outcome measures were significantly influenced by BSA (p < 0.01 in all univariate analyses). Time to reach target temperature was quicker in older patients (p < 0.01). Shivering and meperidine dose were highly intercorrelated (r = 0.6, p < 0.01) and both marginally influenced all four outcome measures. In multivariate analysis, AUC ratio and time to reach target temperature were significantly influenced by BSA (p < 0.01) and meperidine (p < 0.05); AUC-34 was influenced only by BSA (p < 0.01). The AUC-35 was influenced by BSA (p < 0.01), shivering, and total meperidine dose (p < 0.05).

CONCLUSIONS

The most important determinant of effective cooling during endovascular hypothermia is BSA; larger patients are more difficult to cool and maintain in therapeutic range. Older patients cool more quickly. Shivering was well controlled by the combination of meperidine, buspirone, and surface counter-warming and only minimally influenced cooling effectiveness. Future trials of therapeutic hypothermia may include added measures to cool larger patients more effectively.

Abstract 3220: Does Multimodality MRI have Added Benefit in the Diagnosis and Management of “Classic” Hypertensive Intracerebral Hemorrhage?

Introduction: It is unclear whether MRI adds benefit to non-contrast head CT (CT) in the diagnosis and management of patients with “classic” hypertensive intracerebral hemorrhage (HICH) on CT, and whether this additive information justifies MRI costs. We sought to answer this question using a prospective cohort of 159 consecutive patients with spontaneous ICH who systematically underwent CT and multimodality MRI.

Methods: ICH etiology was classified in one of 12 predefined categories along with diagnostic certainty (highly probable, likely and possible), by two blinded neuroradiologists based on CT review (“CT diagnosis”). Two other blinded neuroradiologists reviewed in addition the MRI and determined the most likely diagnosis (“MRI diagnosis”). The “final” diagnosis was used as the reference standard and was assigned by two external, independent and blinded ICH clinician-experts who evaluated all clinical and imaging data including the initial and a 3 month MRI, CT angiography, contrast angiography, pathology and follow-up clinic visits, as available.

Results: Of 159 patients, 86 (54%) had HICH as the final diagnosis. CT and MRI correctly identified 63 (73%) and 78 (91%) of these patients, respectively (P=0.005). Notably, MRI correctly classified eight of nine patients (89%) who had an “unknown” diagnosis by CT. Conversely, 74 patients were classified as HICH by the blinded CT review, and 64 (86%) of these patients had HICH as the final diagnosis. If the CT diagnosis was categorized as highly probable HICH (n=42), then it was almost always correct (98%). If the CT was categorized as likely (n=18) or possible (n=14) HICH, then it was correct in only 72% of cases. MRI increased diagnostic yield in the likely and possible categories by identifying one cavernous malformation (3%) and by improving diagnostic confidence in 19 patients (59%). MRI was wrong in three instances, all in the highly probable category (4%) by incorrectly classifying the etiology of intracerebral hemorrhage due to a possible vascular malformation (n=2) or coagulopathy (n=1).

Conclusions: MRI is more accurate in correctly classifying hypertensive intracerebral hemorrhage than non contrast CT. MRI has significant additive yield over non contrast CT by improving diagnosis and diagnostic confidence in patients for whom the CT diagnosis is of intermediate or low certainty, but not for those diagnosed with a hypertensive intracerebral hemorrhage with high confidence.

Identification of venous signal on arterial spin labeling improves diagnosis of dural arteriovenous fistulas and small arteriovenous malformations

BACKGROUND AND PURPOSE

DAVFs and small AVMs are difficult to detect on conventional MR imaging/MRA or CTA examinations and often require DSA for definitive diagnosis. The purpose of this study was to assess the value of venous signal intensity on ASL imaging for making this diagnosis.

MATERIALS AND METHODS

Two neuroradiologists and 1 neurologist reviewed MR imaging studies in 26 patients, 15 of whom had DSA-proved DAVFs or small (<2 cm) AVMs. Pseudocontinuous ASL was performed at 1.5T with background-suppressed 3D-FSE readout. Using a 5-point scale, these readers assessed the likelihood of positive findings on a DSA study before and after reviewing the ASL findings. Agreement on imaging findings, including venous ASL signal intensity, was performed by using κ statistics. Logistic regression and ROC analysis were performed to determine which imaging findings improved diagnosis.

RESULTS

Venous ASL signal intensity was seen frequently in cases with positive findings on DSA. The sensitivity and specificity of venous ASL signal intensity for predicting positive findings on a DSA study were 78% and 85%, respectively. On ROC analysis, there was a significant increase in the AUC after review of the ASL images (AUC = 0.798 pre-ASL, AUC = 0.891 post-ASL; P = .02). Multivariate regression identified venous ASL signal intensity as the strongest predictor of positive findings on a DSA study, with an odds ratio of 17.3 (95% CI, 3.3-90.4).

CONCLUSIONS

Identifying venous ASL signal intensity improved detection of DAVFs and small AVMs. Attention to this finding may improve triage to DSA in patients with suspected small vascular malformations.