Abstract P587: A Standardized MRA Scanning Protocol Leading to Changes in Stroke Prevention Treatment Plan for Pediatric Sickle Cell Patients

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Parmpreet Dhillon ◽  
Kerry Morrone ◽  
Kevin Hsu ◽  
Daniel Lax ◽  
William Mitchell

Background and Purpose: Magnetic Resonance Angiography (MRA) is performed on pediatric patients with sickle cell disease (SCD) to classify degree of cerebrovascular stenosis, informing stroke risk and treatment plan for stroke prevention. Flow artifact intrinsic to MRA with technician dependent factors can lead to over-interpretation of stenosis. The primary objective of this study was to document any change in stroke prevention therapy that could be attributed to the implementation of a standardized MRA scanning protocol. Methods: A standardized MRA scanning protocol with an echo time (TE) of <5msec based on the SWiTCH (Stroke With Transfusions Changing to Hydroxyurea) study protocol for patients with SCD was implemented at Montefiore Medical Center, NY (MMC) in May 2016. This project included a retrospective chart review of patients at MMC ≤ 21 years of age with SCD who had one MRA head pre-May 2016 AND one MRA post-May 2016. Of the 81 patients that met inclusion criteria, 29 patients were found to have cerebral vasculopathy on pre-May 2016 imaging and included in the analysis. Level of arterial stenosis on MRA, TE, and treatment plans were documented both pre- and post-May 2016. McNemar analysis was used to determine the significance of change in treatment plans before and after implementation of the standardized MRA scanning protocol. Results: 24/29 (83%) patients were on chronic transfusion therapy for cerebrovascular disease pre-May 2016 whereas 18/29 (62%) required chronic transfusion therapy post May 2016. Notably, 6 patients had a resolution of cerebral vasculopathy leading to discontinuation of chronic transfusion therapy whereas 0 patients required escalation of therapy to chronic transfusions. McNemar analysis showed this difference to be statistically significant (p = 0.042). Conclusion: Implementing a standardized MRA scanning protocol allowed for chronic transfusion therapy, which has potentially significant side effects, to be discontinued in 6 out of 24 patients. Minimizing flow artifact with TE <5msec can improve accurate interpretation of true cerebrovascular disease and ensure appropriate treatment plans are in place for stroke prevention.

Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2369-2372 ◽  
Author(s):  
Alan S. Wayne ◽  
Steve E. Schoenike ◽  
Charles H. Pegelow

Abstract Chronic red blood cell transfusion can prevent many of the manifestations of sickle cell disease. The medical costs of chronic transfusion and management of associated side effects, especially iron overload, are considerable. This study was undertaken to evaluate the financial impact of chronic transfusion for stroke prevention in patients with sickle cell anemia. Outpatient charges pertaining to hospital-based Medicare uniform bill (UB-92) codes, professional fees, and iron chelation were evaluated. Data were collected on 21 patients for a total of 296 patient months (mean, 14; median, 14 months/patient). Charges ranged from $9828 to $50 852 per patient per year. UB-92, chelation, and physician-related charges accounted for 53%, 42%, and 5% of total charges, respectively. Of UB-92 charges, 58% were associated with laboratory fees and 16% were related to the processing and administration of blood. Charges for patients who required chelation therapy ranged from $31 143 to $50 852 per patient per year (mean, $39 779; median, $38 607). Deferoxamine accounted for 71% of chelation-related charges, which ranged from $12 719 to $24 845 per patient per year (mean, $20 514; median, $21 381). The financial impact of chronic transfusion therapy for sickle cell disease is substantial with charges approaching $400 000 per patient decade for patients who require deferoxamine chelation. These data should be considered in reference to cost and efficacy analyses of alternative therapies for sickle cell disease, such as allogeneic bone marrow transplantation.


2011 ◽  
Vol 87 (2) ◽  
pp. 221-223 ◽  
Author(s):  
Janet L. Kwiatkowski ◽  
Alan R. Cohen ◽  
Julian Garro ◽  
Ofelia Alvarez ◽  
Ramamorrthy Nagasubramanian ◽  
...  

2017 ◽  
Vol 20 (3) ◽  
pp. 232-238 ◽  
Author(s):  
Wuyang Yang ◽  
Risheng Xu ◽  
Jose L. Porras ◽  
Clifford M. Takemoto ◽  
Syed Khalid ◽  
...  

OBJECTIVESickle cell disease (SCD) in combination with moyamoya syndrome (MMS) represents a rare complication of SCD, with potentially devastating neurological outcomes. The effectiveness of surgical revascularization in this patient population is currently unclear. The authors’ aim was to determine the effectiveness of surgical intervention in their series of SCD-MMS patients by comparing stroke recurrence in those undergoing revascularization and those undergoing conservative transfusion therapy.METHODSThe authors performed a retrospective chart review of patients with MMS who were seen at the Johns Hopkins Medical Institution between 1990 and 2013. Pediatric patients (age < 18 years) with confirmed diagnoses of SCD and MMS were included. Intracranial stroke occurrence during the follow-up period was compared between surgically and conservatively managed patients.RESULTSA total of 15 pediatric SCD-MMS patients (28 affected hemispheres) were included in this study, and all were African American. Seven patients (12 hemispheres) were treated with indirect surgical revascularization. The average age at MMS diagnosis was 9.0 ± 4.0 years, and 9 patients (60.0%) were female. Fourteen patients (93.3%) had strokes before diagnosis of MMS, with an average age at first stroke of 6.6 ± 3.9 years. During an average follow-up period of 11.6 years, 4 patients in the conservative treatment group experienced strokes in 5 hemispheres, whereas no patient undergoing the revascularization procedure had any strokes at follow-up (p = 0.029). Three patients experienced immediate postoperative transient ischemic attacks, but all recovered without subsequent strokes.CONCLUSIONSIndirect revascularization is suggested as a safe and effective alternative to the best medical therapy alone in patients with SCD-MMS. High-risk patients managed on a regimen of chronic transfusion should be considered for indirect revascularization to maximize the effect of stroke prevention.


2015 ◽  
Vol 16 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Christoph J. Griessenauer ◽  
Jeffrey D. Lebensburger ◽  
Michelle H. Chua ◽  
Winfield S. Fisher ◽  
Lee Hilliard ◽  
...  

OBJECT Pediatric patients with sickle cell disease (SCD) and moyamoya syndrome (MMS) are at significant risk for cerebrovascular accidents despite chronic transfusion therapy. Encephaloduroarteriosynangiosis (EDAS) and encephalomyoarteriosynangiosis (EMAS) are additional therapeutic options for these patients. To date, the incidence of complications after and efficacy of EDAS and EMAS in stroke prevention in this population have been described in several institutional case series reports, but no randomized prospective trials have been reported. METHODS The authors retrospectively reviewed the cases of all pediatric patients at the University of Alabama at Birmingham with a history of homozygous hemoglobin S (HbS) and sickle cell/β-thalassemia (SB0 thalassemia) and on chronic transfusion therapy, including 14 patients with MMS who underwent EDAS or EMAS. RESULTS Sixty-two patients with SCD and on chronic transfusion therapy were identified. After exclusion of patients on chronic transfusion therapy for indications other than stroke prevention, 48 patients (77.4%) remained. Of those patients, 14 (29.1%) underwent EDAS or EMAS. Nine (18.8%) and 25 (52.1%) patients were on chronic transfusion therapy for primary or secondary stroke prevention, respectively, but did not undergo EDAS or EMAS. The 14 patients with SCD and radiological evidence of MMS and on chronic transfusion therapy for primary or secondary stroke prevention underwent 21 EDAS or EMAS procedures for progressive vascular disease (92.9% of patients), stroke (71.4%), and/or seizure (7.1%). The mean (± SD) time from initiation of chronic transfusion therapy to EDAS or EMAS was 76.8 ± 58.8 months. Complications included 1 perioperative stroke, 1 symptomatic subdural hygroma, 1 postoperative seizure, and 1 case of intraoperative cerebral edema that required subsequent cranioplasty. Before EDAS or EMAS, the stroke rate was calculated to be 1 stroke per 7.8 patient-years. One additional stroke occurred during the follow-up period (mean follow-up time 33.7 ± 19.6 months), resulting in a post-EDAS/EMAS stroke rate of 1 stroke per 39.3 patient-years, a 5-fold reduction compared with that in the pre-EDAS/EMAS period. The patients’ mean pre-EDAS/EMAS HbS level of 29.5% ± 6.4% was comparable to the mean post-EDAS/EMAS HbS level of 25.5% ± 6.1% (p = 0.104). CONCLUSIONS The results of this retrospective case series in a large cohort of pediatric patients with SCD and MMS suggest that EDAS/EMAS provides a stroke-prevention benefit with an acceptably low morbidity rate. Given the combined experience with EDAS and EMAS for this indication at this and other institutions, a prospective clinical trial to assess their efficacy compared with that of chronic transfusion therapy alone is warranted.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 122-122 ◽  
Author(s):  
Najibah Aliyu Galadanci ◽  
Shehu Umar Abdullahi ◽  
Leah Danielle Vance ◽  
Musa Tabari ◽  
Shehi Abubakar ◽  
...  

Abstract Background: In children with sickle cell anemia (SCA), the routine use of transcranial Doppler (TCD) measurements and regular blood transfusion therapy for those with elevated velocities > 200 cm/sec, has dramatically decreased the rate of strokes. However, blood transfusion therapy for primary stroke prevention is not an option for most children in Africa. In preparation for a phase III trial of hydroxyurea therapy (20 mg/kg/day vs 10 mg/kg/day) for primary prevention of strokesin children with SCA in Africa, we conducted a single site, single-arm feasibility trial of hydroxyurea therapy for primary stroke prevention in children with SCA. Participants were between 5 and 12 years of age, attending the pediatric sickle cell disease clinic of Aminu Kano Teaching Hospital, in Kano, Nigeria. The main objectives of the feasibility trial were to determine the acceptability rate of a hydroxyurea therapy trial to families, and to obtain preliminary evidence of hydroxyurea safety in Africa. Methods: All eligible participants were screened with TCD, non-imaging technique, to determine increased stroke risk; defined as time-averaged maximum velocity (TAMV) greater than or equal to 200cm/sec in the middle cerebral artery (MCA). Families were offered moderate fixed dose hydroxyurea (~20mg/kg/day) for initially 2 years. Primary outcome measures of acceptability were based on three key components required for phase II randomized controlled trial: recruitment rate, retention rate and adherence to the study medication. To determine the expected background rate of adverse events and serious adverse events in this population, children with TCD velocities less than 200cm/sec who were not on hydroxyurea therapy were enrolled. Results: A total of 375 families were approached to be screened for elevated TCD measurements, of which 90% (330 of 375) enrolled; 8% (27 of 330) had two consecutive elevated TCD measurements; and 92% (25 of 27) participated in the trial. A total of 210 participants were identified with TCD velocities less than 200 cm, signed informed consents, and agreed to be followed prospectively in a comparison group. The median age for the trial participants and comparison group were 8 and 6.8 years, respectively. No statistically significant difference was observed in age, sex, ethnicity, height and weight of the treatment and comparison groups. The median time on therapy was 2.1 years (range: 0 to 2.8 years), and the average mean cell volume increased from 85 fl at baseline to 101.3 fl at 2 years. As per protocol, all patients were expected to attend monthly research visits and none were missed (n=total 603 visits). No participant in the treatment group dropped voluntarily from the trial, though one participant was withdrawn due to development of progressive renal failure. After follow up visits, participants in the comparison group with subsequent TCD measurements, were given the option to receive hydroxyurea therapy, and the only 2 with elevated TCD values elected to do so. No stroke occurred in the treatment group and 1 stroke occurred in the comparison group. Hospitalization rates in treatment and comparison groups were 35.1 and 48.0 per 100 patient years respectively, (p=0.06). A total of 9 deaths occurred, 1 death in the treatment group, but after participant withdrew from the trial because of progressive renal disease (1.76 per 100 patient-years) and 8 deaths in the comparison group (1·88 per 100 patient-years) p = 0.94. No participants that died received any PCV-13 vaccinations and only 2 received Hib vaccinations. At the time of death, all participants were prescribed malaria prophylaxis, and 8 of 9 participants were prescribed penicillin prophylaxis. Conclusion: In Nigeria, participants in SPIN Trial with elevated TCD measurements treated with moderate dose of hydroxyurea, showed high rates of successful recruitment, retention and adherence rates to trial medication. Importantly hydroxyurea therapy did not reveal any evidence of excessive toxicity when compared to those not treated with hydroxyurea. Our results provide strong preliminary evidence supporting the current multi-center randomized controlled trial comparing hydroxyurea therapy (20 mg/kg/day vs 10 mg/kg/day) for preventing primary strokes in children with SCA living in Nigeria (1R01NS094041-01;clinical trials.gov NCT 02560935). Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1214-1214
Author(s):  
Andrew E. Mulberg ◽  
Martin Behm ◽  
Catherine Magia ◽  
Robert Adams ◽  
Richard Drachtman ◽  
...  

Abstract The Stroke Prevention Trial in Sickle Cell Anemia (STOP I) demonstrated a 90% risk reduction of first stroke in high-risk pediatric patients with sickle cell disease (SCD) receiving chronic transfusion therapy (CTT) (Adams RJ et al. N Engl J Med1998;339:5–11). Transcranial Doppler (TCD) is key in assessing the need for CTT in children with SCD. A survey of the American Society of Pediatric Hematology/Oncology found wide variation in how hematologists are managing children with SCD (Lane PA et al. Blood2001;98:784a). Recent recommendations by the National Heart, Lung and Blood Institute (NHLBI) suggest TCD and CTT for stroke prevention in high-risk children with SCD; however, there are no data on the utilization of these guidelines in clinical practice. Therefore, we conducted a telephone survey of Sickle Cell Centers to assess the clinical use of TCD and CTT for stroke prevention in pediatric patients with SCD. Invitations to participate were mailed to Directors of 70 centers; interviews were conducted between December 7, 2005 and February 10, 2006. Results from 25 participating centers were analyzed for trends related to use of TCD and CTT in the care of children with SCD. Questions included frequency of TCD based on velocity: &lt;170 cm/sec, 170–200 cm/sec, and &gt;200 cm/sec (Table). Because some participants could not provide an accurate response, responses are not available for all 25 centers in some cases. Frequency of TCD Sickle Cell Centers N = 25 TCD &lt;170 cm/sec Repeat every 6 mo 4 Repeat yearly 13 Repeat every 1–2 y 4 Repeat every 2 y 1 TCD 170–200 cm/sec Repeat every mo 7 Repeat every 2 mo 3 Repeat every 3 mo 6 Repeat every 4–5 mo 3 Repeat every 6 mo 6 TCD &gt;200 cm/sec Repeat every mo 14 Repeat every 2 mo 1 Repeat every 3 mo 3 Based on clinical observations, participants estimated the percentage of patients with eventual worsening of TCD velocity to &gt;200 cm/sec and the approximate number of months to reach that endpoint. Responses indicated an average of 23% and 11.3 months, respectively. Of the 25 centers, all but one indicated that patients with an abnormal TCD (&gt;200 cm/sec) were typically placed on CTT. Four participants stated that results from the STOP trial were the basis for their decision. Fifteen centers indicated that the youngest age they would initiate CTT was 1–2 years. Only 2 directors would consider CTT in children &lt;1 year, and 3 would not initiate CTT until age 5. Although the NHLBI guidelines suggest a hemoglobin S (Hb S) target of &lt;30%, only 5 directors stated that this was their primary factor in determining frequency of CTT. In terms of typical CTT duration, 68% said therapy was indefinite or lifelong, 20% said &lt;1 year, 4% said 2 years, and 4% said until age 18. Although the number of participants was limited, responses indicate there is a relatively wide variation in the application of the NHLBI recommendations for TCD use and CTT in pediatric patients with SCD. The importance of these findings should be correlated both with a more extensive sample of SCD centers and the reported incidence of stroke in the pediatric population.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 270-270 ◽  
Author(s):  
Jennifer Rothman ◽  
Shelly Burgett ◽  
Russell E. Ware ◽  
Courtney Thornburg

Abstract Abstract 270 The use of transcranial Doppler ultrasound (TCD), a non-invasive imaging technique, is now clearly established for detecting high risk of stroke in children with sickle cell anemia (SCA). Children with TCD flow velocities ≥200 cm/s have a 10% risk of primary stroke per year. For these children, chronic blood transfusions (CBT) are recommended and have been shown to reduce the risk of primary stroke by up to 90%. The incidence of stroke has decreased to 0.06–0.17 per 100 patient-years since the institution of TCD screening (Fullerton et al. Blood 2004; Enningul-Egham et al., J Pediatr 2010). Although patients with conditional TCDs (flow velocities 170–199 cm/s) have an estimated stroke risk of 2–5% annually, and their rate of conversion from conditional to abnormal is 23% over an 18 month period (Hankins JS et al., BJH 2008), there are no clinical guidelines for primary stroke prevention in this group. We previously conducted a prospective cohort study of hydroxyurea in 37 children with SCA and TCD velocities >140 cm/sec, and demonstrated that TCD velocities decreased significantly after starting hydroxyurea (Zimmerman et al., Blood 2007; NCT00402480). In order to determine if hydroxyurea provided sustained reductions in TCD velocities, we conducted a retrospective review of these 37 children in this original cohort who had elevated TCD velocities and long-term hydroxyurea treatment. The following data were abstracted from the medical record between April 2000 and September 2009: treatment with hydroxyurea and CBT; adherence with treatments; stroke and non-stroke neurological events; and TCD time-averaged mean velocities (TAMV) immediately prior to initiation of hydroxyurea and at the end of extended follow-up. The primary outcome was comparison of pre and post TCD TAMV using a paired t-test. The mean age of enrollment on the original study was 6.8 years (1.8-14.8) and the mean age at follow-up was 12.9 years (5.3-18.5). The mean follow-up was 5.8 years (0.8-8.5) with an overall follow up of 215.1 patient years. Twenty males and 17 females were enrolled. The mean hydroxyurea dose was 25.2 ± 5.6 mg/kg/day, with one patient discontinuing therapy after 15 months. At follow-up, the mean hemoglobin was 8.9 ± 1.2 g/dL and mean HbF was 16 ± 7.2%. Sustained decreases were observed in both the right MCA (164.8 ± 25.5 cm/s to 124.9 ± 35 cm/s, p<0.001) and left MCA (167.9 ± 25.2 cm/s to 126.9 ± 30 cm/s, p<0.001) for all 37 patients. For the 15 patients with conditional TCD velocities at enrollment, 13 had maximal TAMV that reverted to and were sustained in the normal range (185.8 ± 10.0 cm/s to 132.9 ± 14.5 cm/s, p<0.001). Two converted to abnormal TCD velocities at 1.6 years and 4.5 years for a conversion rate of 13%; one was non-adherent but the other was adherent with hemoglobin of 10.8 g/dL and HbF of 23.5%. These two patients were started on CBT and remain stroke free. There were no primary stroke events observed in the 15 subjects with conditional TCD velocities over a total of 78.1 patient years. Of the 5 patients who had abnormal TCD velocities on enrollment and whose parents refused CBT, 1 patient had a stroke after 0.8 years of hydroxyurea therapy. This was the only patient who continued to have abnormal TCD velocities at MTD, 7 months after starting hydroxyurea. The remaining 4 patients continued to have TCD velocities in the normal range off transfusion therapy over 26.3 patient years. Overall, these data illustrate that treatment with hydroxyurea at MTD in children with SCA and elevated TCD velocities resulted in significantly lower and sustained improvements in TCD velocities. Additionally, for children with conditional TCD velocities, hydroxyurea resulted in a lower than expected conversion to abnormal values, thereby sparing many children from CBT without any noted increase risk of stroke. Hydroxyurea did not, however, protect fully against stroke in one patient who had persistently abnormal TCD velocities and therefore CBT remains the standard of care in this population until larger randomized trials are conducted. Further studies are required to evaluate hydroxyurea for primary stroke prevention in children prior to conversion to abnormal TCD and in children who already have abnormal TCD. The currently funded TCD With Transfusions Changing to Hydroxyurea (TWiTCH) clinical trial, which is scheduled to begin enrollment in late 2010, will help answer this important clinical question. Disclosures: Off Label Use: Hydroxyurea is used to reduce complications of sickle cell anemia.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2496-2496
Author(s):  
Monica L. Hulbert ◽  
Dustin K. Ragan ◽  
Hongyu An ◽  
Cihat Eldeniz ◽  
Geetika Khanna ◽  
...  

Abstract Background Transcranial Doppler (TCD) ultrasonography is the standard stroke screening test for children with sickle cell anemia (SCA). However, approximately 10% of children have inadequate ultrasonographic windows for a successful TCD study, and some clinical sites may lack the equipment or personnel to perform TCDs in children. Magnetic resonance imaging (MRI) techniques can also measure blood flow velocities and could substitute for TCD in these clinical scenarios. We tested the hypothesis that MRI-derived middle cerebral artery (MCA) blood flow velocities would correlate with TCD-derived MCA blood flow velocities in children with SCA. Methods Children age 6 years and up with SCA at their baseline state of health underwent TCD and MRI as part of a prospective clinical study. Imaging TCD of the bilateral MCAs to determine time-average mean of maximum blood flow velocities (TCD-CBFV) were performed using clinical ultrasound equipment. MRIs were performed at 3T without sedation. MRI cerebral time-averaged mean blood flow velocities (MR-CBFV) were measured in the MCAs using phase contrast sequences without cardiac cycle gating to shorten acquisition time and reduce ghosting artifacts. TCD- and MR-CBFV of each hemisphere were compared. Silent cerebral infarctions (SCIs) were categorized as present or absent in each hemisphere. Non-parametric tests were used with a level of significance of <0.05. Statistics were performed in SPSS version 21. Results Twenty hemispheres from 15 children had both TCD-CBFV and MR-CBFV measurements. Median age was 9 years (IQR 6.25-10). In these children, two hemispheres had unobtainable TCDs due to skull thickness, and eight hemispheres had MR-CBFV excluded due to patient motion or poor positioning. The median TCD-CBFV was 116 cm/sec (IQR 90.25-124) and none of the included hemispheres had arterial stenosis or TCD-CBFV in the conditional or abnormal range. Eight included hemispheres were from children receiving chronic blood transfusion therapy for primary or secondary stroke prevention. There was a linear relationship between TCD-CBFV and MR-CBFV (Spearman correlation, ρ=0.781, p<0.001, Figure) although MR-CBFV values were lower than TCD-CBFV values (median difference 32.6%, IQR 26.7-42.8). When evaluating only the children not receiving chronic transfusion therapy, MR-CBFV was significantly higher in 8 hemispheres without SCIs (median 80 cm/sec, IQR 77.8-87.8) than in 4 hemispheres with SCIs (median 60 cm/sec, IQR 44.6-72.3, p=0.004). In a multivariate model adjusting for age, MR-CBFV continued to be associated with presence of SCIs (p=0.036). There was no significant difference in TCD-CBFV when analyzed by SCI status (p=0.2), consistent with published studies of TCD-CBFV and SCIs. Conclusions In this small cohort of children with SCA, MR-CBFV correlated significantly with TCD-CBFV, but MR-CBFV values were approximately 30% lower than TCD-CBFV. This may be due to the method of acquiring MR-CBFV via non-gated methodology, which is known to produce lower blood flow velocity estimates. Further work is needed to determine a threshold for high-risk MR-CBFV values before this modality could be used as a substitute for TCD screening. Lower MR-CBFV was associated with SCIs, suggesting a potential role for MR-CBFV in predicting SCI risk. The relationship between MR-CBFV and SCIs should be explored further. Disclosures Hulbert: Pfizer, Inc.: Other: spouse employment. Fields:NeuroPhage Pharmaceuticals: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2011 ◽  
Vol 117 (3) ◽  
pp. 772-779 ◽  
Author(s):  
Monica L. Hulbert ◽  
Robert C. McKinstry ◽  
JoAnne L. Lacey ◽  
Christopher J. Moran ◽  
Julie A. Panepinto ◽  
...  

Abstract Children with sickle cell disease (SCD) and strokes receive blood transfusion therapy for secondary stroke prevention; despite this, approximately 20% experience second overt strokes. Given this rate of second overt strokes and the clinical significance of silent cerebral infarcts, we tested the hypothesis that silent cerebral infarcts occur among children with SCD being transfused for secondary stroke prevention. A prospective cohort enrolled children with SCD and overt strokes at 7 academic centers. Magnetic resonance imaging and magnetic resonance angiography of the brain were scheduled approximately every 1 to 2 years; studies were reviewed by a panel of neuroradiologists. Eligibility criteria included regularly scheduled blood transfusion therapy. Forty children were included; mean pretransfusion hemoglobin S concentration was 29%. Progressive cerebral infarcts occurred in 45% (18 of 40 children) while receiving chronic blood transfusion therapy; 7 had second overt strokes and 11 had new silent cerebral infarcts. Worsening cerebral vasculopathy was associated with new cerebral infarction (overt or silent; relative risk = 12.7; 95% confidence interval, 2.65-60.5, P = .001). Children with SCD and overt strokes receiving regular blood transfusion therapy experience silent cerebral infarcts at a higher rate than previously recognized. Additional therapies are needed for secondary stroke prevention in children with SCD.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2270-2270
Author(s):  
Julie Kanter ◽  
Mary Dooley ◽  
Logan P Sirline ◽  
Martina Mueller ◽  
Shannon Phillips ◽  
...  

Background: Stroke is one of the most devastating complications of sickle cell anemia (SCA). In 1998, the Stroke Prevention Trial in Sickle Cell Anemia (STOP), demonstrated that a high-risk group of children with SCA could be identified using Transcranial Doppler ultrasound(TCD) and that chronic red cell transfusion therapy (CRCT) could reduce the risk of first ischemic stroke in this group by over 90% (Adams, et al NEJM 1998).At STOP studyenrollment, 9.7% of children with SCA were identified as having an abnormal TCD. Baby HUG, (NCT00006400), an NHLBI supported phase III trial showed that severe anemia in SCA was associated with elevated white blood cell (WBC) and higher TCD velocities (Lebensburger, et al Blood 2010 ). It is unclear if lower hemoglobin (Hb) and/or higher WBC are causative of elevated TCD velocities or correlative biomarkers. As new disease therapies become available, it is important to know the current rate of abnormal TCD and characteristics of those patients. The DISPLACE (Dissemination and Implementation Looking at the Care Environment) project is a multicenter, NHLBI-funded study whose primary purpose is to identify barriers to implementation of stroke screening in SCA and test novel methods for improving outcomes. DISPLACE is a 3-part study: retrospective assessment of current practice, qualitative review of barriers and facilitators to screening and a cluster-randomized intervention implementation project to improve stroke screening. Part 1 of the study showedthat TCD screening rates varied widely among institutions ranging from 30-75.2% (mean 48.4%, median 47%). We are now reporting on the rate of abnormal TCD and the characteristics and outcomes of patients with abnormal TCD. Methods: DISPLACE is a consortium of 28 US centers. Each site performed a rigorous retrospective chart review of children with SCA aged 2-16 years from 2012-2016. To be eligible for inclusion, children must have been seen at their institution at least 2x during the study period and have confirmation of SCA. A custom electronic data capture (EDC) system facilitated entry of de-identified data including demographics, TCD and MRI results, medications, transfusions, and laboratory values. For children with SCA who had TCD or central nervous system imaging prior to 2012, these results were also entered into the EDC. TCD results were recorded in the EDC as normal, conditional or abnormal based on their institutional interpretation. Labs and vitals were entered for each patient in closest proximity to each TCD. Confirmation and adjudication of each abnormal TCD and associated outcomes were performed. Stroke status was also recorded as well as presence or absence of CRCT. Results: In total, 5247 children with SCA are included in the database of whom 5225 should have received a TCD. Of this cohort, 4210 children (80.6%) had at least one TCD recorded in the database. Within this group, 207 (4.9%) of children had an abnormal TCD and 816 (19.4%) had a conditional TCD. For those children who underwent TCD during the study (2012-2016) period, there were 105 (2.9%) abnormal TCD and 501 (13.6%) conditional TCD (Table 1). The mean age of children at the time of abnormal TCD was 6.6 years (range 2-16 yr). The majority of children were <10 yr at first abnormal TCD. Over 30% of patients with an abnormal TCD were identified as receiving hydroxyurea.The mean Hb associated with an abnormal TCD was 7.8 +/- 1.1g/dl (range 5.7-10.6) and the mean WBC was 13 x109/L+/- 3.6 (range 3.9-23.4) (Table 2). Of the 105 patients with abn TCD during the study period, 18% had a stroke. Of the total 5247 patients in the database, 3093 (59%) had been prescribed hydroxyurea (HU) and 999 (19%) were prescribed CRCT. CRCT was prescribed most often for abnormal TCD (37%) or secondary stroke prevention (31%). Discussion: DISPLACE is the largest contemporary cohort of children with SCA. The incidence of abnormal TCD in the DISPLACE cohort is significantly lower than at randomization in the STOP study. The number of children receiving CRCT is higher than expected which may partly account for the decrease in frequency of abnormal TCD. Many patients with abnormal TCD were receiving HU when their TCD was abnormal and were started on CRCT. Additionally, while the outcomes of children with conditional TCD are still being evaluated, many of those children reverted to normal TCD without intervention. These data may also help us redefine the use and interventions needed for abnormal TCD. Disclosures Kanter: NHLBI: Membership on an entity's Board of Directors or advisory committees; bluebird bio, Inc.: Consultancy; SCDAA: Membership on an entity's Board of Directors or advisory committees; Guidepoint Global: Consultancy; GLG: Consultancy; Sangamo: Consultancy, Honoraria; Modus: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Imara: Consultancy; Cowen: Consultancy; Jeffries: Consultancy; Medscape: Honoraria; Rockpointe: Honoraria; Peerview: Honoraria. Adams:GBT: Consultancy, Other: consultancy to companies GBT and Blueburd Bio; Bluebird: Consultancy.


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