scholarly journals Ischemic Stroke in Children and Young Adults with Sickle Cell Disease (SCD) in the Post-STOP Era

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 68-68 ◽  
Author(s):  
Janet L. Kwiatkowski ◽  
Julie Kanter ◽  
Heather J. Fullerton ◽  
Jenifer Voeks ◽  
Ellen Debenham ◽  
...  

Abstract Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for children with abnormal TCD as standard of care. To identify children at high-risk of stroke, annual TCD screening is recommended from ages 2 to 16 years, with more frequent monitoring if the result is not normal. A reduction in stroke incidence in children with SCD has been reported in several clinical series and analyses utilizing large hospital databases when comparing rates before and after the publication of the STOP study in 1998. We sought to determine the rate of first ischemic stroke in a multicenter cohort of children who had previously participated in the STOP and/or STOP 2 trials and to determine whether these strokes were screening or treatment failures. Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3,835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 ranged from a single screening TCD to randomization. STOP 2 also had an observational arm for children on CRCT for abnormal TCD whose TCD had not reverted to normal. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both trials. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3,539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 (depending on site) including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two vascular neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results, reviewed source records to confirm all ischemic strokes, defined as a symptomatic cerebral infarction; discordant opinions were resolved through discussion. For the first Post-STOP ischemic stroke, prior TCD result and treatment history subsequently were analyzed. Results: Of the 3,539 subjects, follow-up data were available for 2,850 (81%). Twelve children who had a stroke during STOP or STOP2 were excluded from these analyses resulting in data on 2,838 subjects. The mean age at the start of Post-STOP was 10.5 y and mean duration of follow-up after exiting STOP/2 was 9.1 y. A total of 69 first ischemic strokes occurred in the Post-STOP observation period (incidence 0.27 per 100 pt years). The mean age at time of stroke was 14.4±6.2 (median 13.8, range 3.5-28.9) y. Twenty-five of the 69 patients (36%) had documented abnormal TCD (STOP/2 or Post-STOP) prior to the stroke; 15 (60%) were receiving CRCT and 9 (36%) were not (treatment data not available for 1 subject). Among the 44 subjects without documented abnormal TCD, 29 (66%) had not had TCD re-screen in the Post-STOP period prior to the event; 7 of these 29 (24%) were 16 y or older at the start of Post-STOP, which is beyond the recommended screening age. Four of the 44 (9%) patients had inadequate TCD in Post-STOP (1 to 10.7 y prior to event). Six (14%) had normal TCD more than a year before the event (1.2 - 4 y); all but one of these children were younger than 16 y at the time of that TCD. Only 5 (11%) had a documented normal TCD less than 1 year prior to the event. Conclusions: In the Post-STOP era, the rate of first ischemic stroke was substantially lower than that reported in the Cooperative Study of Sickle Cell Disease, prior to implementation of TCD screening. Many (39%) of the Post-STOP ischemic strokes were associated with a failure to re-screen according to current guidelines, while only 11% occurred in children who had had recent low-risk TCD. Among those known to be at high risk prior to stroke, treatment refusal or inadequate treatment may have contributed. While TCD screening and treatment are effective at reducing ischemic stroke in clinical practice, significant gaps in screening and treatment, even at sites experienced in the STOP protocol, remain to be addressed. Closing these gaps should provide yet further reduction of ischemic stroke in SCD. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3402-3402 ◽  
Author(s):  
Julie Kanter ◽  
Janet Kwiatkowski ◽  
Heather J. Fullerton ◽  
Jenifer Voeks ◽  
Ellen Debenham ◽  
...  

Abstract Background: Primary hemorrhagic stroke is a rare complication of sickle cell disease (SCD) that usually occurs in adults. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) screening with indefinite chronic red cell transfusions (CRCT) for patients with abnormal TCD as standard of care. Despite a notable improvement in the incidence of infarctive stroke in children with SCD after the introduction of TCD screening protocols, it is unclear how this protocol will affect the rate of hemorrhagic stroke. Presumably, early TCD screening and subsequent initiation of CRCT in high risk patients will prevent the progression of cerebral vasculopathy, which should decrease the risk of hemorrhagic stroke; however this has not been proven. Using the large multicenter cohort of children who participated in STOP and/or STOP 2 trials, we sought to assess whether the rate of hemorrhagic stroke was impacted by the use of TCD screening and/or CRCT. Subjects and Methods: Between 1995 and 2005, STOP and STOP 2 (STOP/2) were conducted at 26 sites in the US and Canada. These studies included 3835 children, ages 2 to 16 y with SCD type SS or S-beta-0-thalassemia. Participation in STOP/2 required at least a single screening TCD for randomization. Patients on STOP 2 also had an observational arm for children started on CRCT who had an abnormal TCD. The Post-STOP study was designed to follow-up the outcomes of children who participated in one or both of trials. For all participants the date of their last encounter in STOP/2 was defined as the start of their Post-STOP period. 19 of the 26 original study sites participated in Post-STOP, contributing a total of 3539 (92%) of the STOP/2 subjects. After exit from STOP/2, these children received TCD screening and treatment according to local practices. Data abstractors visited each clinical site and obtained retrospective data from STOP/2 study exit to 2012-2014 including follow-up TCD and brain imaging results, clinical information, and laboratory results. Two separate neurologists, blinded to STOP/2 status and prior TCD and neuroimaging results adjudicated all suspected strokes. Results: Follow-up data were available for 2850 of the 3539 subjects (81%). Twelve children who had a stroke during the STOP study period were further excluded from this analysis resulting 2838 subjects. The mean age at the start of Post-STOP was 10.5 years and mean duration of follow-up after exiting STOP/2 until time of last medical encounter was 9.1 years. A total of 31 patients had a primary hemorrhagic stroke during the Post-STOP observation period (incidence 0.12 per 100 pt years). The mean age at time of stroke was 16.2+5.6 (median 15.3 range (4.8-30.2) years of age. Of those 31 patients, only 52% had a TCD during Post-STOP prior to the event. Seven of those children who underwent screening had documentation of an abnormal TCD prior to the event (5 during STOP era and/or 3 Post-STOP). However, only 1/7 patients (14%) were documented on CRCT at the time of the stroke (4 patients were receiving HU and 2 patients had unknown treatment). Discussion: Although less common than infarctive stroke, patients with SCD are at increased risk for hemorrhagic stroke. There is an increased risk of mortality for patients who suffer from hemorrhagic stroke (up to 26% in some reports in the 2 weeks after the event). It is unclear if TCD screening and subsequent initiation of CRCT will impact the rate of hemorrhagic stroke in the long term. In our results, a similar incidence of primary hemorrhagic stroke was noted although the patients were overall younger than previously reported (16.5+/- 5.5 years versus 20-29 years in Cooperative Study of Sickle Cell Disease). Many patients who had a hemorrhagic stroke (48%) had not undergone TCD screening during the Post-Stop period. Additionally, although a safe stopping point for CRCT has not been established in patients who have had an abnormal TCD, only 1 patient was documented on CRCT at the time of the event (14%). Thus, it is unclear at this time whether TCD screening and subsequent, lifelong continuation of CRCT could have prevented these other events. Clearly, these results demonstrate that improved implementation of STOP protocol is needed as well as further evaluation of the impact of this protocol on the incidence of hemorrhagic stroke. Disclosures No relevant conflicts of interest to declare.


2019 ◽  
Vol 6 ◽  
pp. 2333794X1984702 ◽  
Author(s):  
Michael D. Cabana ◽  
Julie Kanter ◽  
Anne M. Marsh ◽  
Marsha J. Treadwell ◽  
Michael Rowland ◽  
...  

National guidelines recommend that providers counsel all patients with sickle cell anemia about hydroxyurea (HU) therapy and screen children with sickle cell anemia annually for the risk of stroke with transcranial Doppler (TCD). We surveyed a national convenience sample of sickle cell disease clinicians to assess factors associated with low adherence. Adherence was 46% for TCD screening. Low adherence was associated with a lack of outcome expectancy (eg, a belief that there would be poor patient follow-up to TCD testing; P < .05). Adherence was 72% for HU counseling. Practice barriers (eg, lack of support staff or time) and a lack of agreement with HU recommendations were associated with low adherence ( P < .05). This study demonstrates that different types of strategies are needed to improve TCD screening (to address follow-up and access to testing) versus HU counseling (to address physician agreement and practice barriers).


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1541-1541 ◽  
Author(s):  
Roberto F Machado ◽  
Mariana Hildescheim ◽  
Laurel Mendelsohn ◽  
Gregory J Kato ◽  
Mark T Gladwin

Abstract Abstract 1541 Poster Board I-564 Background Elevations in NT-proBNP levels are associated with hemolysis-associated pulmonary hypertension and mortality in adults with sickle cell disease. The association of this vasculopathy with the risk of stroke has not been explored. The Cooperative Study of Sickle Cell Disease (CSSCD) is the largest cohort of adult and pediatric patients with sickle cell disease with the longest median follow-up. Using stored plasma samples from patients enrolled in the CSSCD, we tested the hypothesis that adult patients with high levels of NT-proBNP would be at a high risk of death and stroke and that pediatric patients with a high BNP might be at a high risk of stroke. Methods A threshold NT-pro-BNP value previously identified to predict mortality in adults with sickle cell disease was used to determine the association between the risk of stroke and mortality in a cohort of 758 participants (pediatric cohort, n=428 and adult cohort, n=330) in the CSSCD. Results The prevalence of an abnormal NT-proBNP level ≥ 160 pg/ml was 27.6 % in patients in the adult CSSCD cohort. The prevalence of a NT-proBNP level ≥ 160 pg/ml was 27.4 % in the pediatric cohort, which is at least in part explained by known higher normal NT-proBNP levels in children, especially during the first year of life. The incidence of the development of a high NT-proBNP level in subjects with a normal baseline level was 6 % over a mean follow-up time of 5.9 years (incidence rate per 100-person years of 1.03) in the pediatric cohort and 16.5 % over a mean follow-up time of 1.9 years in the adult cohort (incidence rate per 100-person years of 8.59). In subjects with normal baseline levels, multivariate logistic regression analysis of clinical and laboratory factors associated with the development of a high NT-proBNP level included increasing age (OR 3.43, 95% CI 1.6-7.2, P = 0.001), low hemoglobin (OR 0.47, 95% CI 0.3-0.7, P < 0.001), high white blood cell count (OR 1.69, 95% CI 1.05-2.7, P = 0.03), high creatinine (OR 2.22, 95% CI 1.1-4.3, P = 0.02), blood urea nitrogen (OR 1.64, 95% CI 1.2-2.3, P = 0.004), alanine aminotransferase (OR 1.26, 95% CI 1.01-1.6, P = 0.04) and uric acid levels (OR 2.32, 95% CI 1.4-3.8, P = 0.001), and history of leg ulcers (OR 7.46, 95% CI 2.0-28.5, P = 0.003). Elevated NT pro-BNP levels were associated with indices of hemolytic anemia (hemoglobin: OR 0.33, 95% CI 0.2-0.4, P < 0.001) and a history of stroke (OR 1.86, 95% CI 0.9-3.7, P = 0.02). An NT-pro-BNP level ≥160 pg/ml was a predictor of mortality (RR 6.24, 95% CI 2.9-13.3, P < 0.001) and stroke (RR 3.84, 95 % CI 1.0-14.3, P = 0.05) in this cohort. Conclusions A high NT-proBNP level is a major risk factor for death in patients with sickle cell disease. These findings provide further support for a mechanistic link between hemolytic anemia and the development of cardiovascular complications in this patient population. Finally, we have identified a novel widely available biomarker of the risk of death and stroke in sickle cell disease. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1004-1004
Author(s):  
Shaina Willen ◽  
Nirmish Shah ◽  
Courtney Thornburg ◽  
Jennifer Rothman

Abstract Abstract 1004 Hydroxyurea (HU) is approved for use in adults with Sickle Cell Disease (SCD) and increases the production of fetal hemoglobin (HbF). Increased HbF is associated with decreased clinical severity in adults and children with SCD, such as decreased numbers of vaso-occlusive events, transfusions, and hospitalizations. Higher HbF at initiation of HU is predictive of HbF response, but association between age of hydroxyurea initiation and HbF response has not been investigated. We hypothesize that starting hydroxyurea at an early age may improve hematological and clinical response. In order to determine if younger age at hydroxyurea initiation affects the percentage of HbF achieved with hydroxyurea, we conducted a retrospective cohort study. We identified subjects enrolled in the Duke University Medical Center Comprehensive Sickle Cell program who initiated hydroxyurea when they were less than 17.99 years of age and were prescribed hydroxyurea for at least six months. The following data were abstracted from the medical record between December 1996 and April 2011: age, hemoglobin, percentage HbF, and mean corpuscular volume (MCV) at start of HU and at maximum tolerated dose (MTD) of HU therapy. The correlation coefficient and p-values for various parameters were calculated. Seventy-three patients (41 males and 32 females) were included in the analysis. The mean age at hydroxyurea initiation was 5.5 years (1.2–14.1). The mean hydroxyurea dose at MTD was 28.6 ± 3.2 mg/kg/day. At initiation, the mean hemoglobin was 8.2 ± 1.2 g/dL, the mean MCV was 83±7.4 fl and mean HbF was 10 ± 5.7%. At MTD, the mean hemoglobin was 9.4 ± 1.1 g/dL, the mean MCV was 99 ± 11.1 fl, and the mean HbF was 21.7 ± 9.4%. As expected, at MTD, an elevated MCV was correlated with elevated fetal hemoglobin (r2= 0.19, p= 0.0001) [Table 1]. There was a statistically significant relationship between the age at HU initiation and the HbF at MTD (r2= 0.08, p= 0.015) [Figure 1] as well as the age at HU initiation and the hemoglobin at MTD (r2= 0.19, p= 0.016). The relationship between the age at starting HU and the overall change in HbF (DHbF) was not statistically significant (r2= 0.01, p= 0.41). There was not a statistically significant relationship between age at HU initiation and the MTD of HU (r2= 0.003, p= 0.61). The 6 patients started on HU at age less than 2 years (mean 1.5 ± 0.3 years) maintained a mean elevated HbF of 19.1 ± 5% at last documented follow-up with follow-up ranging from 1.4–13 year of uninterrupted hydroxyurea use. Starting hydroxyurea therapy at a younger age appears to improve HbF response as measured at MTD, although there is variability in the level of fetal hemoglobin attained. There is not an association seen with the DHbF or dose at MTD and age at hydroxyurea initiation. In summary, starting hydroxyurea at a younger age, when HbF is >20%, leads to persistence of HbF production and overall improvement in hematological efficacy. This was not simply the result of achieving MTD at a younger age before physiologic decline of HbF. Disclosures: Off Label Use: Hydroxyurea for complications of sickle cell disease in pediatrics. Shah:Eisai: Research Funding; Adventrx: Consultancy.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4767-4767
Author(s):  
Giovanna Graziadei ◽  
Alessia Marcon ◽  
Martina Soldarini ◽  
Ilaria Gandolfi ◽  
Luisa Ronzoni ◽  
...  

Abstract Abstract 4767 Background. Sickle-Cell Disease (SCD) is one of the most common severe monogenic inherited disorders worldwide, due to hemoglobin S (HbS), with reduced affinity for the oxygen. HbS polymerization, leading to erythrocyte rigidity, vaso-occlusion and hemolytic anemia, is central in the pathophysiology and crucial for the clinical outcome. The term SCD refers to Sickle Cell Anemia (SCA) due to homozygosis for βS allele, HbS/β-thalassemia (T-SCD) due to compound of β-thal and βS allele, and HbSC disease, owing to the coinheritance of βS and βcalleles. SCD is a multiorgan disease characterized by recurrent acute events and progressive organ damage, worsening during the life. Aims. This is a retrospective monocentric study aimed to assess and compare the clinical complications among 59 adult SCD patients, followed at the Hereditary Anemia Centre of the Foundation IRCCS “Ca Granda” Ospedale Maggiore Policlinico, in Milan, Italy. Methods. Mutation analysis of the b globin gene was established by direct DNA sequencing on the ABI Prism 310 genetic analyzer. Clinical and hematological features were evaluated by routine tests and physical examination, with special attention to the erythropoiesis stress parameters as LDH values and extramedullary erythropoietic (EE) masses. Results. Fifty-nine adult SCD patients, 16 SCA and 43 T-SCD, were evaluated. In T-SCD patients detected b-mutations were severe (b°) in 69.8%, and moderate or mild (b+-b++) in 30.2%. The mean age of SCA patients was 36±9 and 41±11 years for T-SCD patients. For both groups the mean follow-up was 20±6 years, while the mean age at the presentation in our Centre was 32±8 years in SCA patients and 31±10 years in T-SCD ones. Five out of 16 (31.2%) SCA patients and 16/43 (37.2%) T-SCD patients were male. HbF mean levels were 6.9±5.1% and 10.1±7.2%, respectively in SCA and T-SCD group; surprisingly Hb mean levels were lower in SCA (9.3±1.3 g/dl) than in T-SCD (9.9±1.4 g/dl) patients. Comparing SCA and T-SCD, there was statistically significant difference in splenic features: splenectomy was performed in 2/16 (12.5%) SCA patients vs 21/43 (48.8%) T-SCD patients (p-value < 0.01). Splenomegaly was absent in SCA, while was detected in 11/22 (50%) T-SCD (p-value < 0.0001); all SCA patients had functional asplenia, not observed in T-SCD patients; splenic infarctions were absent in SCA patients and were detected in 7/22 (31.8%) T-SCD patients, of whom 5 had splenomegaly and 2 had normal spleen size (pvalue <0.001). On the other side, there was not statistically significant difference in the prevalence of stroke, acute chest syndrome (ACS), bone pain crisis, sepsis, leg ulcers and priapism. However, we observed some clinical differences, even if not statistically significant. Cholecistectomy was performed in 4/16 (25%) SCA patients vs 17/43 (39.5%) T-SCD patients, and gallstones were detected respectively in 5/12 (41.7%) and in 14/26 (53.8%) of SCA and T-SCD patients. Thrombotic events were absent in SCA patients, compared to 4/43 (9.3%) T-SCD patients. Furthermore, we detected EE in 3/16 (18.6%) SCA and in 3/43 (7%) T-SCD, all carrying b° thal mutations. We underlie that Hb levels and LDH values were higher in SCA than in T-SCD patients (823±295 vs 689±209 U/L). About the treatment, 14/16 (87.5%) SCA and 31/43 (72%) T-SCD underwent to top-up transfusion; 5/43 (11.6%) T-SCD were regularly transfused. Seven out of 16 (43.8%) SCA and 18/43 (41.8%) T-SCD patients were treated with Hydroxycarbamide (HU). Criteria for transfusion therapy were: painful crisis not responsive to HU, major clinical complications, such as stroke or ACS, extramedullary erythropoietic masses associated with high LDH levels and low Hb values. Conclusions. These data suggest that SCA and T-SCD patients have similar clinical course. Splenomegaly is present only in T-SCD patients, probably due to the increased amount of extravascular hemolysis. Surprisingly, SCA patients showed EE and lower Hb levels with higher LDH values compared to T-SCD ones. This could be related to the prevalence of intravascular hemolysis, that can lead to erythropoietic stress in SCA, even if tissues are better oxygenated in these patients because of biochemical characteristic of HbS in terms of decreased oxygen affinity. These observations could be important to evaluate transfusion and HU treatment. Disclosures: Cappellini: Novartis: Research Funding.


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 ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3187-3187 ◽  
Author(s):  
Kenneth I. Ataga ◽  
Charity Moore ◽  
Susan Jones ◽  
Oludamilola Olajide ◽  
Dell Strayhorn ◽  
...  

Abstract Introduction: The prevalence of pulmonary hypertension (PHT) is high in patients with sickle cell disease (SCD). Although most patients have only mild increases in their pulmonary artery systolic pressure (PASP), the presence of PHT is strongly associated with an increased risk of death. While PHT seen in SCD is thought to progress over time, both the rate of development of PHT and the factors that affect disease progression remain unknown. Methods: The 41 subjects in this study were drawn from an original cohort of 60 patients followed in the Sickle Cell Clinic at UNC-Chapel Hill. All patients were previously evaluated for PHT (defined using an age-, sex-, and BMI-adjusted reference range). Of the 60 patients in the original cohort, six are now deceased and 13 others were not available for repeat evaluation. The PASP was determined using Doppler echocardiography and then applying the modified Bernoulli equation (PASP = 4V2 + right atrial pressure). Individuals were not studied if they: 1) showed clinical evidence of left ventricular failure; 2) had a recent acute illness (e.g., vaso-occlusive crisis); or 3) had experienced an episode of acute chest syndrome within the preceding 4 weeks. Means and standard deviations were calculated for all measures at the time of initial evaluation and at the time of follow-up. Results: Of the 41 subjects in our study, PHT was originally present in 12, while no evidence of PHT was present in 29. Of the 29 subjects who initially had no evidence of PHT, 4 (or 14%) have now developed PHT (mean follow-up period of 3.3 ± 0.4 years). In these 4 subjects, the mean PASP at the time of initial and follow-up evaluations respectively were: 37.0 ± 2.0 mm Hg vs. 55.8 ± 11.0 mm Hg. The patients who developed PHT during the course of the study had lower systolic BP (143 ± 12 mm Hg vs. 128 ± 12 mm Hg), lower fetal hemoglobin levels (6.2 ± 5.7 % vs. 4.2 ± 3.7 %), and higher platelet counts (276 ± 119 X 103/μL vs. 426 ± 96 X 103/μL) at the time of their follow-up analyses. By contrast, 3 of the 12 subjects (or 25%) who were thought to have PHT at the time of their original evaluations were found to have normal PASP determinations at the time of their repeat echocardiograms (mean follow-up period of 3.2 ± 0.6 years). In these latter 3 subjects, the mean PASP values at the time of the initial and follow-up evaluations respectively were: 40.0 ± 4.6 mm Hg vs. 33.7 ± 4.7 mm Hg. Conclusion: In this small group of patients with SCD, we found that PHT developed in 14% of subjects who had no evidence of PHT 3 years earlier. Based on this observation, it seems that periodic echocardiograms to screen for the development of PHT would be appropriate. On the other hand, our observation that some patients initially classified as having PHT failed to have elevated PASP measurements at the time of follow-up illustrates the limitation of a single echocardiographic evaluation in establishing this diagnosis. Because of the increase in PASP that occurs during acute vaso-occlusive episodes, and the difficulty usually encountered in distinguishing steady state from crisis, the initial elevation of the PASP in these patients could have resulted from sub-clinical crisis states. For these reasons, a patient found to have an elevated PASP at the time of a screening echocardiogram should have a repeat study, and perhaps a right heart catheterization, before the diagnosis of PHT is firmly established.


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.


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