Nelson, Jeffrey

Importance Annual rates of first intracranial hemorrhage (ICH) from unruptured brain arteriovenous malformations (AVMs) are often quoted as 2% to 4% in clinical practice. Precise estimates and risk factors are unavailable to inform treatment decisions. Objective To provide estimates of rates and risk factors for first ICH in a large cohort study of unruptured brain AVMs. Design, Setting, and Participants The Multicenter Arteriovenous Malformation Research Study (MARS) included data from 9 cohorts, each contributing 100 or more unruptured brain AVMs. The study was conducted from 2017 to 2023 with retrospective and prospective data collection for existing cohorts and/or new recruitment. This was an international study (2 population-based and 7 referral-based cohorts) that included participants diagnosed with an unruptured brain AVM. Exposures Demographic, clinical, and angiographic characteristics. Main Outcome and Measure The primary outcome was time to first ICH after diagnosis of unruptured brain AVM. Data were collected using standardized definitions; missing data were imputed. Cox regression analysis was performed, censoring at first brain AVM treatment, death, or last visit, and allowing baseline hazards to vary by cohort. Results A total of 3225 individuals were eligible for participation in this study. After 195 exclusions, 3030 participants (median [IQR] age, 38 [25-50] years; 1524 female [50.3%]) were included. Among 2989 participants with unruptured brain AVMs, 1333 (45%) presented with seizure. The median (IQR) maximal brain AVM diameter was 3.1 (2.2-4.4) cm, 248 of 2466 AVMs (10%) had exclusively deep venous drainage, 297 of 2690 (11%) were in supratentorial deep or cerebellar locations, and 457 of 2440 (19%) had associated arterial aneurysms. First ICH occurred in 159 participants over 11 339 person-years of follow-up for an ICH rate of 1.40 (95% CI, 1.20-1.64) per 100 person-years. Significant independent risk factors included (1) increasing age category at diagnosis (hazard ratio [HR], 0.87; 95% CI, 0.53-1.41 for those aged 20 to 39 years; HR, 1.23; 95% CI, 0.74-2.04 for those aged 40 to 59 years; and HR, 2.01; 95% CI, 1.14-3.57 for those aged 60 years vs younger than 20 years; P = .008), (2) presence of associated aneurysms (HR, 1.66; 95% CI, 1.06-2.59; P = .03), and (3) cerebellar or supratentorial deep location (HR, 1.87; 95% CI, 1.16-3.00; P = .01). Conclusions and Relevance The annual ICH rate from unruptured brain AVM was lower than that commonly cited in clinical practice. Increasing age, associated arterial aneurysms, and cerebellar or supratentorial deep brain AVM location were associated with risk of first ICH. These results may be used to counsel patients about the natural history of unruptured brain AVMs.

Introduction: The long-term effects of interventional treatment (with surgery, stereotactic radiosurgery, or endovascular embolization) for unruptured brain arteriovenous malformations (uBAVM) are uncertain. We address this in a large multi-center international cohort study comparing risk of intracranial hemorrhage (ICH) in the treated and untreated course of uBAVM patients. Methods: We pooled individual patient data (n=3,291) from 10 cohorts and imputed missing data. Survival analysis was performed from time of uBAVM diagnosis to intracranial hemorrhage (ICH) using Cox models, stratified by cohort, censoring at death or last follow-up, and including BAVM interventional treatment as a time-varying covariate. We tested for an interaction of treatment with follow-up time, then estimated the association of interventional treatment with ICH, adjusting for propensity quintile. Individual treatment propensity scores were calculated using logistic regression with Spetzler-Martin grade, sex, diagnosis age and year, cohort, and presence of presenting symptoms (seizures, headaches, and/or deficits). Results: Median cohort age was 36 years, 48% were female, and 77% received ≥1 treatment modality for uBAVM during follow-up. 373 ICH occurred during 32,054 person-years of follow-up (median=6.6y), for an ICH rate of 1.16 per 100 P-Y. Overall, treatment was not associated with risk of ICH (HR=1.12, 95% CI=0.89-1.51, p=0.33). However, we observed a strong interaction between treatment and follow-up time (p<0.001): between 0-1 year, treatment was associated with higher risk of ICH (HR=3.48, 95% CI: 2.26-5.37, p<0.001); between 1-10 years, we found no association between treatment and risk of ICH (HR=1.02, 95% CI: 0.73-1.45, p=0.87); after 10 years, treatment was associated with a lower risk of ICH (HR=0.46, 95% CI: 0.30-0.70, p<0.001). Survival curves for untreated and treated courses crossed around 17 years. Conclusion: After accounting for treatment propensity for uBAVM, we found an initial increased risk of ICH in the treated relative to untreated course, which continually declined over time with survival curves crossing around 17 years. These results require confirmation in a randomized controlled trial of uBAVM with long-term follow-up.

Background: Cerebral cavernous angiomas with symptomatic hemorrhage (CASH) carry highest rebleed rates and are targeted for novel interventions. A multisite clinical trial readiness project (clinicaltrials.gov NCT03652181) aims to identify clinical and functional changes over time in trial eligible CASH patients. Methods: Adult patients from 5 high volume centers with a CASH in the prior year and no planned surgical intervention were enrolled. In addition to demographic, clinical, and imaging review, patients underwent baseline, 1 year and 2 year NIH-stroke scale (NIHSS), modified Rankin scale (mRS), Euro-QOL 5D-3L (EQ-5D-3L) and EQ VAS (visual analog score), and PROMIS 29 assessments. Recurrent symptomatic hemorrhages (SH) were verified. We assessed the hemorrhage rate, change in scores/scales over time, and determined which scales/scores were most affected in patients with SH. Results: 123 patients completed baseline assessments and were prospectively followed (60.9% female; mean age 44.1 years; 39.1% familial; 41.5% brainstem location). As of reporting date, 89 of 104 (86%) and 58 of 76 (76%) cases have completed assessments. There were 16 SHs during 147 patient-years of follow up (10.9% per patient year). At baseline, 111 (90.2%) of patients had NIHSS 0-2 and 77 (62.6%) patients had mRS baseline 0-1 which improved to 40 (95.2 %) and 43 (75.4%) at 2 years. At baseline, 54 (43.9%) of patients had at least one moderate to severely abnormal PROMIS-29 domain compared to 13 (26.5%) at 2 years. EQ-5D-3L baseline demonstrated a moderate proportion of patients reporting some difficulty with pain (48.8%), anxiety (41.5%), and activity (41.5%) which improved to 28%, 30%, and 34% respectively at 2 years. Patients with a prospective SH were more likely than those without recurrent SH at 2 years to display mild functional decline (0.5 SD) of most PROMIS-29 domains, a mRS of 2 or higher and an abnormal EQ- self-care (P<0.05). Other scales/scores were not significantly different between the groups. Conclusion: We report SH rate and functional outcome at baseline and rates of changes during 2 years in trial eligible CASH patients. The PROMIS-29, mRS, and EQ-self-care domains were most discriminative in patients with recurrent SH. No test was 100% specific.

Background: Patients with cerebral cavernous angiomas with symptomatic hemorrhage (CASH) have high risk of disability from recurrent bleeding. Candidate medications to prevent rebleeding in CASH lesions will require multisite clinical trials with standardized data collection. Objective: To report the prevalence and baseline cohort features in CASH patients and establish a research network infrastructure for trials. Methods: This prospective observational cohort study includes adults with radiologically verified CASH lesion within 1-year of consent. Exclusions include prior or planned surgical intervention, spinal location, or prior brain irradiation. Six sites enrolled patients into the screening and clinical assessment portion of the study starting July 2018. Patients also had the option to participate in the follow up biomarker validation at 4 sites. Baseline demographics, clinical and imaging information, and outcomes (mRS, PROMIS-29, NIHSS, and EuroQol-5D) were collected. Biomarker imaging included dynamic contrast enhanced quantitative perfusion (DCEQP) and quantitative susceptibility mapping (QSM) that correlated with symptomatic bleeding. Descriptive statistics were performed and one-sample t-test was used to compare whether mean T-scores for PROMIS-29 domains differed significantly from a reference population. Results: As of May 2020, 849 CASH patients were screened of whom 110 (13%) were eligible and enrolled; 73 also enrolled into the biomarker validation study. Average age at enrollment was 46±16 years at a mean of 4.4 months after symptom onset; 53% were female, 41% were familial, and 43% of CASH lesions were brainstem location. At enrollment, 90% of the cohort had independent functional outcome (mRS ≤ 2 and NIHSS <5). Perceived health problems affecting QoL were reported in >30% (EuroQol-5D). CASH cases had significantly worse anxiety but better depression and social satisfaction scores compared to a general population (all P<0.01). Baseline DCEQP and QSM measures did not differ significantly across sites. Conclusion: We demonstrate feasibility of multisite recruitment of CASH patients and report prevalence of baseline features that will aid in design of clinical trials and inclusion of appropriate outcome measures.

Background: Accurate and reliable models of intracranial hemorrhage (ICH) risk in the untreated course of brain arteriovenous malformation (BAVM) patients are needed to help weigh the risk-benefit of treatment. We present preliminary estimates of rates and risk factors for ICH or death in the Multicenter AVM Research Study (MARS), which is the largest individual patient data meta-analysis (IPDMA) of cohort studies of unruptured BAVM. Methods: Longitudinal data from 9 cohorts comprising 2,839 unruptured BAVM at time of diagnosis were included: UCSF (n=557), Macquarie (n=462), Kaiser Permanente Northern California (n=354), Columbia (n=335), Barrow Neurological Institute (n=324), Tiantan Hospital (n=303), Mayo Clinic-Rochester (n=244), Scottish Intracranial Vascular Malformation Study (n=194), and Toronto Western Hospital (n=66). Clinical and angiographic data were collected using standardized definitions across cohorts. Cox proportional hazards analysis of time-to-event (ICH or death) in the untreated course after diagnosis was performed, censoring at first treatment or last visit. Baseline hazard rates were stratified by cohort to account for different rates and follow-up times. Results: The combined cohort was 49% female, 72% white race, and 17% Hispanic ethnicity; mean age at diagnosis was 37±17 years and mean follow-up was 3.4±7.0 years. The most common presenting symptom was seizures (43%). Mean AVM size was 3.5±1.9 cm and 46% were Spetzler-Martin grade I-II. Overall, 123 ICH and 131 deaths occurred over 9,608 person-years (PY) for an event rate of 2.64 per 100 PY [95% CI: 2.34-2.99]. Cox regression analyses adjusting for age at diagnosis (HR=1.67 [1.54, 1.82], P<0.001) identified cerebellar location (HR=1.73 [1.03-2.93], P=0.040) and exclusively deep venous drainage (HR=1.83 [1.09-3.09], P=0.022) as predictors. Conclusion: Our current model identified increasing age, exclusively deep venous drainage, and cerebellar location as risk factors for ICH or death in the untreated course of unruptured bAVM patients. Review of imaging data, multiple imputation of missing angioarchitectural data, and additional data from pending cohorts will provide greater power to search for additional risk factors in this ongoing IPDMA.