Background: The incidence of and mortality from coronary heart disease (CHD) is significantly higher among African Americans (AAs) compared to Whites, even after adjusting for traditional CHD risk factors. Studies suggests that the unexplained excess risk might be the result of genetic modifiers associated with African ancestry conferring a higher risk of CHD. One such gene variant is the sickle cell mutation. The heterozygous state, or sickle cell trait (SCT), with a prevalence of 8 – 12% among AAs, was previously deemed clinically benign; however, recent evidence indicates that SCT is associated with increased risk of chronic kidney disease venous thromboembolism and sudden death following exertion. Individuals with SCT have higher circulating levels of C-reactive protein, fibrinogen, prothrombin fragment 1.2 and D-dimer. We hypothesized that AAs with SCT have a higher risk for myocardial infarction (MI) and coronary heart disease (CHD) than AAs who are homozygous for wild-type hemoglobin. Methods: We obtained genotype and phenotype data from the Women’s Health Initiative (WHI) REasons for Geographic and Racial Differences in Stroke (REGARDS), Multi-Ethnic Study of Atherosclerosis (MESA), Jackson Heart Study (JHS) and Atherosclerosis Risk In Communities (ARIC) cohorts. The outcomes were incident MI or CHD. Incident MI was defined as adjudicated non-fatal or fatal MI, while incident CHD was defined as 1) adjudicated non-fatal MI, 2) fatal MI, 3) documented coronary revascularization procedures or 4) non-MI CHD death. SCT status was determined by either direct genotyping or imputation for rs334 using the 1000Genome reference panel. Homozygous individuals and those with a prior history of CHD were excluded. Individuals with incident “micro MI”, only defined in REGARDS, were also excluded from the analysis. Analysis was performed separately in each cohort using a Cox proportional hazard models to estimate the hazard ratio (HR) for incident MI or CHD comparing SCT carriers to non-carriers. Models in each cohort were adjusted for age, sex, study site or region of residence, hypertension or systolic blood pressure, diabetes, serum LDL or HDL or total cholesterol, and population stratification (using principal components of global ancestry). The results from each cohorts were then meta-analyzed using a random effect model due to significant heterogeneity between studies (I2 = 39.1%, p = 0.02 for MI meta-analysis and I2 = 56%, p = 0.01 for CHD meta-analysis). Results: A total of 20,053 African American men and women were included in the combined sample; 1503 with SCT (7.5% prevalence). Average ages in years at baseline were: 65.0 ± 6.0 in WHI (N = 2248), 62.0 ± 9.2 in REGARDS (N = 10573); 62.2 ± 10.2 in MESA (N = 1556); 50.0 ± 11.9 in JHS (N = 2133); and 54.0 ± 6.0 in ARIC (N = 3543). There were no statistically significant differences in the distribution of traditional cardiovascular risk factors by SCT status within cohorts, except that atrial fibrillation was more prevalent among REGARDS participants with SCT compared to those without SCT (9.9% vs. 7.8%, p = 0.03). The crude incidence rate of MI per 1000 person years in those with SCT compared to those without SCT was: 4.0 vs. 5.2 in WHI; 5.7 vs. 5.0 in REGARDS; 5.8 vs 4.3 in MESA, 2.0 vs 2.1 in JHS; and 4.1 vs 5.9 in ARIC. For CHD, the crude incidence rate was: 5.8 vs. 7.2 in WHI, 8.9 vs. 7.4 in REGARDS; 15.4 vs. 6.4 in MESA; 3.4 vs. 3.4 in JHS; and 10.5 vs. 9.5 in ARIC. The HR (95% CI) for MI was: 0.96 (0.49 – 1.89) in WHI; 1.27 (0.8 – 2.0) in REGARDS; 1.84 (0.74 – 4.60) in MESA; 1.24 (0.28 – 5.44) in JHS; and 0.68 (0.42 – 1.10) in ARIC. And that for CHD was: 1.05 (0.63 – 1.74) in WHI; 1.49 (1.01 – 2.18) in REGARDS; 2.82 (1.48 – 5.38) in MESA; 1.45 (0.50 – 4.19) in JHS; and 1.10 (0.80 – 1.50) in ARIC. Meta-analysis showed that, while SCT status was not significantly associated with incident MI (1.10 [0.73 – 1.64]), it was significantly associated with incident CHD (1.42 [1.02 – 1.98] Figures 1a and 1b). Conclusions: This study showed a significant association between SCT and incident CHD, but not MI. Our conclusion is limited by the significant heterogeneity that existed between studies. Since SCT status was not associated with MI, but was associated with CHD, further work is needed to confirm these findings, determine which CHD component(s) explain the observed association and elucidate the possible mechanism(s) involved. Abstract source

Introduction: Cardiopulmonary fitness is significantly reduced among individuals with sickle cell disease (SCD). Cardiopulmonary fitness is also an important predictor of morbidity and all-cause mortality in the general population. However, the relationship between fitness and clinical outcomes in SCD has not been well studied. The objectives of this analysis were to: 1) determine the factors associated with fitness in a cohort of adults with SCD, and 2) evaluate the relationship of fitness to hospitalization for pain and acute chest syndrome (ACS) and overall mortality. We hypothesized that clinical factors such as age, sex, hemoglobin, SCD genotype and cardiopulmonary disease significantly affect fitness, and that poor fitness is a predictor of more frequent hospitalizations for pain and ACS and higher mortality in adults with SCD. Methods: A cohort of adults with SCD was constructed from participants enrolled in phase 2 of the Cooperative Study of Sickle Cell Disease (CSSCD) who underwent exercise testing (modified Balke treadmill protocol). Primary measure for fitness was total treadmill duration. Retrospective pain or ACS hospitalization rates were calculated using events in the 3 years prior to exercise testing. Mortality and prospective hospitalization rates for pain and ACS were calculated using events after exercise testing with a minimum 6 month follow-up. Results of pulmonary function testing (PFT), echocardiography, and laboratory testing within 3 years of exercise testing were included in our analysis. Standard descriptive analyses were performed (SPSS V24). Multivariable negative binomial and Cox proportional hazards models were constructed to evaluate the relationship of fitness to ACS and pain hospitalization rates and mortality, respectively. Multivariable linear models were constructed to determine factors associated with fitness. Results: A total of 223 participants had valid exercise testing data (64% female, 70% hemoglobin SS or S/b0 thalassemia, mean age 43.3 ± 7.5 years, mean hemoglobin 9.1 ± 2.2 g/dl, mean follow-up 2.7 ± 0.7 years after exercise testing). Participants completed a mean of 11.6 ± 5.2 min on the treadmill, with 87% completing >= 3 stages but only 17% completing all 10 stages. We categorized fitness into tertiles of treadmill duration (5.7 vs. 11.8 vs. 18.1 min, p < 0.001). Age (45.2 vs. 43.1 vs. 41.3 years, p = 0.007), baseline hemoglobin (8.5 vs. 9 vs. 9.8 g/dl, p = 0.003), as well as the proportion of females (77 vs. 71 vs. 40%, p < 0.001) and participants with abnormal PFT (58 vs. 35 vs. 39%, p = 0.008), differed significantly across fitness tertiles. Pain or ACS hospitalization rates during the 3 years prior to exercise testing were not significantly different across fitness tertiles. Using multivariable linear regression, male sex (β = 3.1, p < 0.001), lower age at exercise testing (β = –0.14, p = 0.003), and higher hemoglobin (β = 0.44, p = 0.049) were independently associated with higher fitness, with abnormal PFT trending toward significance (β = –1.28, p = 0.07). In this model, genotype, tricuspid regurgitant jet velocity (TRJV) >= 2.5 m/s, and pain and ACS hospitalization rates prior to exercise testing were not significantly associated with fitness. Using a negative binomial regression model, we found that fitness did not predict future pain or ACS episodes after adjustment for age, sex, genotype, hemoglobin and TRJV. Fitness also did not predict survival in our cohort (hazard ratio, 0.97; 95% CI [0.84, 1.13], p = 0.71), in which death was reported in only 9 participants. In our Cox regression model, male sex (HR 7.1; 95% CI [1.3, 38.9]; p = 0.02) and lower hemoglobin (HR 0.56; 95% CI [0.36, 0.88]; p = 0.01) were independent predictors of death, but age at exercise testing, abnormal PFT and TRJV >= 2.5 m/s were not. Conclusions: In adults with SCD, lower fitness is significantly associated with female sex, older age, lower hemoglobin and abnormal PFT. Fitness did not predict survival or future pain or ACS events in the CSSCD. Given that cardiopulmonary fitness remains an important predictor of all-cause mortality in the general population, larger scale prospective studies in SCD are needed to evaluate the impact of regular exercise on improving fitness, quality of life, clinical outcomes and mortality in this population. Abstract source

Background: Sickle cell anemia (SCA) is characterized by significant phenotypic variability. DOVE1 was a Phase 3, double-blind, randomized, parallel-group, placebo-controlled, multinational study that investigated the efficacy and safety of prasugrel, a P2Y12 adenosine diphosphate receptor antagonist, for reduction of vaso-occlusive crises (VOCs), a composite of painful crisis or acute chest syndrome, in 2- to <18-year-olds with SCA (age cohorts: 2 to <6 years, 6 to <12 years, and 12 to <18 years) Methods: DOVE was conducted at 51 sites in 13 countries across 4 continents. A total of 341 subjects were randomized (prasugrel, n=171; placebo, n=170) and SCA genotypes (homozygous hemoglobin S; hemoglobin Sβ0 thalassemia) were included. Eligibility required >=2 VOCs in the prior year. Baseline clinical and laboratory characteristics and study endpoints were compared by region. Since no overall treatment effect was found, data provided reflect the combined 341 subjects (Americas, N=57; sub-Saharan Africa [SSA], N=148; North Africa/Middle East, N=110; Europe, N=26). Abstract source

Background: High utilization of emergency department (ED) services among those with sickle cell disease (SCD) compared to the general population and compared to those with other chronic diseases is well documented in the literature. Some reports note that high utilization is episodic. Most analyses address the problem as a consistent one within patients, rather than consistent over time across the patient population but sporadic for patients. Reducing the high rate of ED utilization among patients with SCD requires an understanding of temporal patterns of ED utilization, the consistency of ED utilization over time by patients and the proportion of the population affected at any given time. Methods: CDC has developed the Sickle Cell Data Collection program (SCDC) to conduct state level surveillance in this disease, and to continue and improve upon work begun through the Registry and Surveillance System in Hemoglobinopathies (RuSH). Through SCDC, California has collected ED and hospitalization data for years 2005-2014 on 4,325 people with SCD. A period of high ED utilization among this cohort was defined as three or more ED encounters (either treat and release or admission to the hospital from the ED) for any diagnosis (not only SCD diagnoses) each fewer than 30 days from the prior visit. The start of an episode of high utilization is the date of the first ED encounter; the end is the date of the last eligible ED encounter. All cohort members were divided into categories of utilization using the proportion of time spent in periods of high utilization divided by the total time in cohort. Total time is cohort is defined as the length of time from the earliest appearance in the ED or hospital data 2005-2014 to the latest appearance. The five categories were defined as no episodes of high ED utilization, and approximate quartile groups for those with high ED utilization: 1.1 to 3.0%, 3.1-10.0%, 10.1% or greater. Age categories (pediatric is < 21 years, and adult is 21 years or older) are defined as patient age at close of study (end of 2014) or at death if prior. Patient ID beginning with P is a pediatric, A is adult in the figures. Results: There were 4,325 individuals with 27,694 person years in the cohort (mean 6.4 person years, median 7.6 person years). Sixty-three percent (n=2,715) of the cohort were aged 21 years and older. Forty-five percent, (n=1,955, 513 pediatric and 1,442 adults) had at least one episode of high utilization during the 10 year study for a total of 7,866 episodes of high utilization. Forty-three percent of patients with one or more high utilization episodes were male, and 63% were between the ages of 20 and 50. Nine percent of these high utilizing patients’ total time in the cohort was made up of episodes of high utilization. The mean time span from start of episodes of high utilization to end of the episodes was 63.3 days, median 35 days; mean number of ED visits per episode was 9.0, median 4.0. Most episodes of high utilization were brief: 42.2% included just three visits, and 70.7% included five or fewer ED visits. Among these individuals with episodes of high utilization, the mean number of such episodes was 4.0 over the 10 years study period, and the median was 2.0. Most (76.4%) had five or fewer high utilization episodes, and 35.5% had just one (n = 693). Sample utilization patterns, including hospital admissions, are shown in Figure 1. Conclusions: We demonstrate that among individuals with SCD seen in a population-based, statewide surveillance system, periods of high ED utilization are common, but most SCD patients have only a limited number of short episodes of such utilization. We found that high ED utilization is episodic rather than consistent within individuals, and that while the range of time spent in episodes of high utilization varies, few patients are high utilizers of ED services over a long period of time. Statewide surveillance that follows individual patients over time and in different hospital settings and includes ED utilization (including visits not coded as being related to SCD), provides high quality public health information to inform clinicians and healthcare systems in their development of efforts to reduce ED utilization among those living with SCD. Abstract source

Background: Delayed hemolytic transfusion reaction (DHTR) is a life threatening complication of transfusion in sickle cell disease (SCD). This syndrome is underestimated because of a clinical picture that resembles a vaso-occlusive crisis (VOC) and the frequent absence of detectable antibodies. Several retrospective studies have evaluated the frequency of DHTR based on case reports. We conducted a prospective, longitudinal, single center study to determine the incidence of DHTR and the risk of developing DHTR depending on the transfusion regimen: chronic versus punctual. Methods and patients: SCD patients aged over 18 years, undergoing a transfusion, were enrolled in this study. A total of 697 transfusion episodes (TE) in 312 patients were included during 30 months. Some patients had multiple TE during the period. The post transfusion outcome of the patients was assessed up to one month after the included TE. DHTR was confirmed based on the rapid disappearance of HbA (> 50% 15 days post-transfusion) associated with two of the following criteria up to three weeks after transfusion: VOC symptoms, dark urine, worsening anemia, increased LDH. Transfusion episodes were divided into chronic (336 TE in 111 patients) and punctual (361 TE in 201 patients). Chronic transfusions were defined as regular transfusions to treat chronic complications or for primary/secondary prevention of complications. Short transfusion program during pregnancy was considered as punctual transfusions if patients were not previously regularly transfused. The study obtained approval of the local Ethics Committee. Abstract source

Introduction: The Dependent Coverage Provision (DCP) of the 2010 Affordable Care Act aims to improve (1) access to medical care among individuals aged 18-25 nationwide and (2) the efficiency of care by increasing appropriate outpatient care and reducing avoidable inpatient care. Individuals became eligible for coverage under their parents' private insurance in late September 2010. Previous studies have demonstrated improvement in access to care among those eligible for DCP, but no studies have examined the experience of young adults with serious disease requiring chronic medical care such as sickle cell disease (SCD). We hypothesized SCD patients aged 18-25 had increased access to commercial insurance, higher use of outpatient and lower use of inpatient care in the years following DCP implementation compared to patients ineligible for DCP. Methods: This national analysis of patients aged 0-30 with qualifying SCD claims was performed using the Truven Health Analytics MarketScan Commercial Claims and Encounters dataset 2003-2013. The dataset contains commercial insurance claims of employees and dependants representing more than 50 million lives annually. We included patients with a continuous 12 month enrollment, and >1 inpatient or outpatient SCD claim in a given year. SCD claims included those with ICD-9 codes for homozygous SCD (HgbSS), sickle cell thalassemias (HgbSC, HgbSbo, HgbSb+) with and without crises, or splenic sequestration and/or acute chest syndrome. We defined 2003-2010 as pre-DCP and 2011-2013 as post-DCP. Inflation adjusted annual average per person spending, defined as reimbursements paid to providers, of SCD related inpatient and outpatient care was calculated. Descriptive statistics of number and share of patients by year and age cohort were calculated. Descriptive statistics of number of outpatient and inpatient claims by year and age cohort were calculated. A segmented regression analysis was performed to test for changes in trend of patient share by age cohort after the DCP. Access is defined as share of individuals having any claim type during the year. A difference-in-differences analysis was performed to study changes in medical care use and spending among individuals aged 18-25 pre and post-DCP, compared to those 26-30 and 12-17. Abstract source

Background: Sickle cell anemia (SCA) has been associated with cognitive dysfunction, perhaps in part due to vascular occlusive disease. Increasing evidence suggests that some complications of SCA might also affect those with sickle cell trait (SCT), including chronic and end-stage kidney disease and venous thromboembolism. Thus, SCT may not be a benign condition. Based on data that SCA may influence cognition, we hypothesized that SCT is a risk factor for cognitive impairment in African-Americans. Methods: Participants were African-American adults aged 45 and older from a national prospective cohort study of 30,239 white and black Americans; the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. The study collected extensive baseline risk factor data, and conducted baseline and annual cognitive function testing using the Six-Item Screener (SIS), a validated telephone-administered instrument for global cognitive function that yields a score from 0 to 6. Participants included in this analysis were African-Americans without SCA who had available data on baseline and at least one follow up SIS, SCT genotyping and principal components of ancestry. Participants with baseline SIS ≤4 were excluded as having prevalent impairment. Incident cognitive impairment was defined as having a score at the most recent assessment of ≤4. Logistic regression was used to model associations of SCT with incident cognitive impairment, adjusted for risk factors (listed in table footnote). Results: Among 5,507 participants (mean age 63.5), 731 developed incident cognitive impairment with average follow up of 8.1 years. Those with incident cognitive impairment were more likely to be male with prebaseline history of cardiovascular diseases, diabetes, hypertension and dyslipidemia, and had lower income and education. They were slightly more likely to have SCT (7.9% vs 7.3%). In sequentially adjusted models (table), there was no association of SCT with incident cognitive impairment, with a fully adjusted odds ratio of 1.16 (95% CI 0.79-1.71). There were no significant differences in this odds ratio by age, diabetes, hypertension, dyslipidemia, cardiovascular disease, kidney disease or smoking status (p for interaction with SCT all >0.4). Conclusion: In this prospectively followed general population cohort of middle-aged and older adults with longitudinal cognitive function testing, SCT was not associated with increased risk of incident cognitive impairment overall or in various high-risk subgroups. These findings suggest that unlike in SCA, SCT does not result in chronic cerebrovascular dysfunction. To confirm and extend these findings, further work is needed on associations of SCT with specific domains of cognitive function. Abstract source

Background: Individuals with sickle cell disease (SCD) treated with hydroxyurea (HU) in clinical trials have had fewer hospitalizations and vaso-occlusive pain episodes than those on placebo. Since 2014, HU has been recommended for all children with Hemoglobin SS/S-β0 thalassemia, and many SCD centers have increased HU utilization. The effect of expanded HU treatment on hospitalization rate has not been reported in a population of children clinically treated with HU. In a pediatric SCD center cohort, we tested the hypothesis that increasing prevalence of HU treatment was associated with reduced hospitalization rate per patient-year and in total hospitalizations. Methods: PedsNet, a PCORI-funded clinical research initiative, was queried for all patients with inpatient or outpatient encounters for SCD at St. Louis Children's Hospital (SLCH) from 2010 through 2015. Data from patients with ICD-9 codes indicating any genotype of SCD were included. Patients were considered to be receiving HU when it was prescribed on 2 or more outpatient encounters. Exclusion criteria were lack of SCD diagnosis confirmation, lack of outpatient visits at SLCH, and presence of a significant unrelated medical condition. Patients were censored at their 21st birthday or date of hematopoietic stem cell transplant. Data generated at the adult hospital were excluded. All hospitalizations in the final cohort were included for analysis, regardless of diagnosis code. For comparisons, patients were grouped as having a severe genotype (SS, S-β0 thalassemia, SD) or less-severe genotype (SC, S-β+ thalassemia). Statistical analysis was performed using SAS 9.4. Logistic and Poisson regression were used to compare proportions and rates between groups, respectively. Generalized Estimating Equations were used to account for within patient correlation. Abstract source

Patients with sickle cell disease (SCD) suffer from frequent and severe episodes of pain that are associated with hospitalizations, impaired quality of life and increased mortality. Current treatment options are scarce. Oxidative stress appears to play a pivotal role in the pathophysiology of SCD. Pilot studies have demonstrated that administration of the antioxidant N-acetylcysteine (NAC) effectively reduces markers of oxidative stress in SCD and may decrease the hospitalization rate for painful crises. NAC is a safe, inexpensive and well-tolerated drug that has been used for years for various indications. The primary aim of this study was to evaluate the effect of NAC on the frequency of daily pain in patients with SCD. We conducted a randomized (1:1), double-blind, placebo-controlled, parallel-group trial at 11 sites across The Netherlands, Belgium and the United Kingdom. Patients were eligible for participation if they were >=12 years of age, had either HbSS, HbSC, HbSβ⁰- or HbSβ⁺-thalassemia with a history of at least 1 painful crisis per year over the 3 years prior to enrolment. At randomization patients were assigned to receive either oral NAC 600 mg twice daily or placebo for a total duration of 6 months. Patients had monthly checkups during the study. The primary endpoint was the rate of SCD related pain days per patient year, assessed daily with the use of pain diaries. Secondary endpoints included the rate of days with painful crises, admission days, hospitalizations and days with home analgesic use, the severity of pain, the time to first painful crisis and hospitalization, the number of adverse events and the effect on quality of life and various blood markers. The primary intention-to-treat analysis of this study was limited to patients with a minimal completed diary observation time of 110 days. Sensitivity analyses were done in both all randomized patients as well as a subset with >=80 days of observation time. Lastly, an additional per protocol analysis was performed on patients with adequate adherence (>=80% of tablets used) and >=110 days of completed diary observation time. Abstract source

Introduction: Vaso-occlusive episodes are the most common complication experienced by individuals with sickle cell disease (SCD). Treatment in an emergency department (ED) is often required and significant variability in care exists. In 2014, NHLBI published evidence based recommendations suggesting treatment with either an individualized opioid dosing or standard weight-based protocol; however the supporting evidence grade was Consensus – Panel Expertise. As outlined in the results section, the aim of this project was to compare change in pain scores, patient safety and system utilization variables between patients randomized to an individualized or weight based (standard) dosing protocol for treatment of VOC from arrival to discharge in an ED setting. Methods: A randomized controlled trial was conducted in two EDs (OH and NY). Adults with SCD were eligible for inclusion and recruited during a hospitalization, clinic visit or at the end of an ED visit. Patients were randomized to treatment with an individualized opioid dosing protocol (developed by the SCD physician based on patients’ prior opioid use) or standard weight based protocol. Both protocols were supported by the NHLBI recommendations for treatment of VOE (2014) to include repeat dosing. Protocols were made available on the electronic medical record for future ED visits (up to five visits/patient), should they occur. ED physicians were informed of the protocol and ordered analgesics. Research staff was notified when ED visits occurred for enrolled patients and obtained assessments of pain (0-100 cm VAS) every 30 minutes from placement in the ED to one of 3 study endpoints: 1) 6 hours; 2) decision to admit to the hospital; 3) discharge home. The unit of analysis was the ED visit rather than patient. The primary outcome was change in pain score from arrival to study endpoint. Research staff reviewed the medical record 30 days after the ED visit to determine secondary outcomes of hospital admission, re-admission and new ED visits within 72 hours, 7 and 30 days post the index ED visit. The medical record was reviewed for administration of narcan, intubation, or assisted ventilation. A hierarchical linear mixed effects model adjusting for nested patient and site effects were used to test for a difference in the mean pain change scores in the treatment arms. Generalized Linear Models adjusting for nested patient and site effects were performed to evaluate differences in the dichotomized secondary outcomes. Results: 106 patients enrolled in the study with 52 patients (sites: 25 OH, 27 NY) contributing a total of 126 ED visits over 12 months. Among the 52 patients with visits, the median number of ED visits/patient was 2.0, 58% were male, and the median age was 27 years (range: 21 to 60). No patients in either treatment arm required narcan, intubation, or assisted ventilation. Abstract source