Key Contextual Factors Involved with Participation in Medical and Genomic Screening and Research for African American and Caucasian Americans: A Qualitative Inquiry American Journal of Community Genetics

Tremendous progress has been made promoting diversity in recruitment for genomic research, yet challenges remain for several racial demographics. Research has cited intertwined fears of racial discrimination and medical mistrust as contributing factors. This study aimed to identify key factors to establishing trust in medical and genomic screening and research among African Americans and White Americans. Participants completed online focus groups and resulting transcripts were analyzed using a qualitative descriptive approach, with content analysis methods based on recommendations by Schreier. Fifteen African Americans and 23 Caucasian Americans participated in the study, 63% of which were female. The mean age of participants was 38.53 (SD = 16.6). The Overarching Theme of Trust is Context Dependent was identified, along with the following five themes describing elements influencing trustworthiness for our participants: 1) Professional Experience, Education, and Training Bolster Trust; 2) Trust Depends on Relationships; 3) Cross-checking Provided Information is Influential in Establishing Trust; 4) Trust is Undermined by Lack of Objectivity and Bias; and 5) Racism is an Embedded Concern and a Medical Trust Limiting Component for African Americans. To effectively address mistrust and promote recruitment of diverse participants, genomic research initiatives must be communicated in a manner that resonates with the specific diverse communities targeted. Our results suggest key factors influencing trust that should be attended to if we are to promote equity appropriately and respectfully by engaging diverse populations in genomic research.

Selection, optimization and validation of ten chronic disease polygenic risk scores for clinical implementation in diverse US populations

Polygenic risk scores (PRSs) have improved in predictive performance, but several challenges remain to be addressed before PRSs can be implemented in the clinic, including reduced predictive performance of PRSs in diverse populations, and the interpretation and communication of genetic results to both providers and patients. To address these challenges, the National Human Genome Research Institute-funded Electronic Medical Records and Genomics (eMERGE) Network has developed a framework and pipeline for return of a PRS-based genome-informed risk assessment to 25,000 diverse adults and children as part of a clinical study. From an initial list of 23 conditions, ten were selected for implementation based on PRS performance, medical actionability and potential clinical utility, including cardiometabolic diseases and cancer. Standardized metrics were considered in the selection process, with additional consideration given to strength of evidence in African and Hispanic populations. We then developed a pipeline for clinical PRS implementation (score transfer to a clinical laboratory, validation and verification of score performance), and used genetic ancestry to calibrate PRS mean and variance, utilizing genetically diverse data from 13,475 participants of the All of Us Research Program cohort to train and test model parameters. Finally, we created a framework for regulatory compliance and developed a PRS clinical report for return to providers and for inclusion in an additional genome-informed risk assessment. The initial experience from eMERGE can inform the approach needed to implement PRS-based testing in diverse clinical settings.

Does genetic testing offer utility as a supplement to traditional family health history intake for inherited disease risk?

CONTENT

This study examines the potential utility of genetic testing as a supplement to family health history to screen for increased risk of inherited disease. Medical conditions are often misreported or misunderstood, especially those related to different forms of cardiac disease (arrhythmias vs. structural heart disease vs. coronary artery disease), female organ cancers (uterine vs. ovarian vs. cervical), and type of cancer (differentiating primary cancer from metastases to other organs). While these nuances appear subtle, they can dramatically alter medical management. For example, different types of cardiac failure (structural, arrhythmia, and coronary artery disease) have inherited forms that are managed with vastly different approaches.

METHODS

Using a dataset of over 6,200 individuals who underwent genetic screening, we compared the ability of genetic testing and traditional family health history to identify increased risk of inherited disease. A further, in-depth qualitative study of individuals for whom risk identified through each method was discordant, explored whether this discordance could be addressed through changes in family health history intake.

FINDINGS

Of 90 individuals for whom genetic testing indicated significant increased risk for inherited disease, two-thirds (66%) had no corroborating family health history. Specifically, we identify cardiomyopathy, arrhythmia, and malignant hyperthermia as conditions for which discordance between genetic testing and traditional family health history was greatest, and familial hypercholesterolaemia, Lynch syndrome, and hereditary breast and ovarian cancer as conditions for which greater concordance existed.

CONCLUSION

We conclude that genetic testing offers utility as a supplement to traditional family health history intake over certain conditions.

Strong protective effect of the APOL1 p.N264K variant against G2-associated focal segmental glomerulosclerosis and kidney disease

African Americans have a significantly higher risk of developing chronic kidney disease, especially focal segmental glomerulosclerosis -, than European Americans. Two coding variants (G1 and G2) in the APOL1 gene play a major role in this disparity. While 13% of African Americans carry the high-risk recessive genotypes, only a fraction of these individuals develops FSGS or kidney failure, indicating the involvement of additional disease modifiers. Here, we show that the presence of the APOL1 p.N264K missense variant, when co-inherited with the G2 APOL1 risk allele, substantially reduces the penetrance of the G1G2 and G2G2 high-risk genotypes by rendering these genotypes low-risk. These results align with prior functional evidence showing that the p.N264K variant reduces the toxicity of the APOL1 high-risk alleles. These findings have important implications for our understanding of the mechanisms of APOL1-associated nephropathy, as well as for the clinical management of individuals with high-risk genotypes that include the G2 allele.

Strong protective effect of the APOL1 p.N264K variant against G2-associated focal segmental glomerulosclerosis and kidney disease

Black Americans have a significantly higher risk of developing chronic kidney disease (CKD), especially focal segmental glomerulosclerosis (FSGS), than European Americans. Two coding variants (G1 and G2) in the APOL1 gene play a major role in this disparity. While 13% of Black Americans carry the high-risk recessive genotypes, only a fraction of these individuals develops FSGS or kidney failure, indicating the involvement of additional disease modifiers. Here, we show that the presence of the APOL1 p.N264K missense variant, when co-inherited with the G2 APOL1 risk allele, substantially reduces the penetrance of the G1G2 and G2G2 high-risk genotypes by rendering these genotypes low-risk. These results align with prior functional evidence showing that the p.N264K variant reduces the toxicity of the APOL1 high-risk alleles. These findings have important implications for our understanding of the mechanisms of APOL1 -associated nephropathy, as well as for the clinical management of individuals with high-risk genotypes that include the G2 allele.

Selection, optimization, and validation of ten chronic disease polygenic risk scores for clinical implementation in diverse populations

Polygenic risk scores (PRS) have improved in predictive performance supporting their use in clinical practice. Reduced predictive performance of PRS in diverse populations can exacerbate existing health disparities. The NHGRI-funded eMERGE Network is returning a PRS-based genome-informed risk assessment to 25,000 diverse adults and children. We assessed PRS performance, medical actionability, and potential clinical utility for 23 conditions. Standardized metrics were considered in the selection process with additional consideration given to strength of evidence in African and Hispanic populations. Ten conditions were selected with a range of high-risk thresholds: atrial fibrillation, breast cancer, chronic kidney disease, coronary heart disease, hypercholesterolemia, prostate cancer, asthma, type 1 diabetes, obesity, and type 2 diabetes. We developed a pipeline for clinical PRS implementation, used genetic ancestry to calibrate PRS mean and variance, created a framework for regulatory compliance, and developed a PRS clinical report. eMERGE's experience informs the infrastructure needed to implement PRS-based implementation in diverse clinical settings.

Hypertension severity, apparent treatment resistant hypertension and hyperuricemia in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study

BACKGROUND

Prior studies have identified an association between hypertension and hyperuricemia; however, there has been limited research on the association between hypertension severity and hyperuricemia.

METHOD

We studied 997 Black and white adults with serum urate data from the reasons for geographic and racial differences in stroke (REGARDS) study. Hypertension was defined as SBP ≥ 140 mmHg or DBP ≥ 90 mmHg or self-reported use of antihypertensive medication. Apparent treatment-resistant hypertension (aTRH) was defined as a SBP ≥ 140 mmHg or DBP ≥ 90 mmHg with concurrent use of three classes of antihypertensive medications, or taking four or more classes of antihypertensive medication regardless of BP level. Controlled BP was defined as SBP <140 mmHg and DBP <90 mmHg.

RESULTS

Overall 5.9% of participants had aTRH and 36.6% had hyperuricemia, defined as serum urate >7.0 mg/dl for men and >6.0 mg/dl for women. After full multivariable adjustment, the odds ratio (OR) for hyperuricemia associated with hypertension was 1.60 [95% confidence interval (95% CI): 1.06-2.40]. Compared to participants not taking antihypertensive medication, the ORs for hyperuricemia for participants taking one, two and three classes of antihypertensive medication without aTRH were 1.98 (95% CI: 1.23-3.20), 2.08 (95% CI: 1.25-3.43), 4.31 (95% CI: 2.07-8.97), respectively, and 3.96 (95% CI: 1.75-8.96) for aTRH. Compared to participants without hypertension, the odds ratios for hyperuricemia were 1.67 (95% CI: 1.08-2.58) and 1.46 (95% CI: 0.88-2.44) among those with hypertension with and without controlled BP, respectively. Diuretic use was associated with a higher odds of hyperuricemia.

CONCLUSION

This study suggests that individuals taking more classes of antihypertensive medication may benefit from monitoring for hyperuricemia.

Abstract MP19: An eGFR Polygenic Score Predicts Chronic Kidney Disease in African Americans

Chronic kidney disease (CKD) is a risk factor for cardiovascular disease and early death. Genetic factors contribute to CKD, and recently, polygenic scores (PGS) have been developed to quantify risk for complex diseases, such as CKD. However, African ancestry populations are underrepresented in both CKD genetic studies and PGS development overall; moreover, European-ancestry derived PGSs demonstrate diminished predictive performance in African ancestry populations. This study aimed to develop a PGS for CKD using genotype and phenotype data from African American (AA) participants of observational cohort studies. We obtained score weights from a meta-analysis of genome-wide association studies (GWAS) for estimated glomerular filtration rate (eGFR) in the Million Veteran Program (MVP) and Reasons for Geographical and Racial Differences in Stroke (REGARDS) Study (total n~66,000). We then optimized the PGS in a cohort of AAs from the Hypertension Genetic Epidemiology Network (HyperGEN) Study (n~1,900) using the PRS-CS software and evaluated the predictive performance of the PGS at multiple global shrinkage parameters. We further adjusted the PGS for APOL1 risk status. In HyperGEN, the eGFR-based PGS was significantly associated with the odds of prevalent CKD—defined as baseline eGFR <60 mL/min/1.73m 2 — in logistic regression models adjusted for age, sex, and population structure. Further, accounting for APOL1 risk status—a putative variant for CKD unique to those of sub-Saharan African descent—improved the score’s accuracy, with the APOL1 -adjusted PGS explaining 1.9% (1.1% without APOL1 ) of the variance in CKD and an area under the curve (AUC) of 58.9% [95% CI: 53.0%-64.9%] (without APOL1 , 58.2% [95% CI: 52.3%-64.1%]). Sensitivity analyses and validation in external cohorts, as well as comparisons to previously published PGS, are ongoing. In this study, we developed a PGS that was significantly associated with CKD with improved predictive accuracy in AAs over previously published PGS.

Abstract 27: Genetic Risk of Blood Pressure on Antihypertensive Efficacy and Apparent Treatment Resistant Hypertension in Participants of the Genetics of Hypertension Associated Treatments (GenHAT) Study

Background: Polygenic risk scores (PRS) have shown promise in complementing existing clinical risk factors and improving early diagnosis of cardiovascular disease. Recently, several studies have developed PRS for blood pressure traits; however, few have examined to what extent these PRS predict antihypertensive (AHT) efficacy.

Hypothesis: We hypothesize that applying a systolic blood pressure (SBP) PRS developed and trained in multi-ancestral observational studies will predict response to chlorthalidone (CHL), as well as non-response to AHT treatment (apparent treatment resistant hypertension, aTRH), among African Americans (AA).

Methods: We applied an optimized multi-ancestry PRS generated in a pooled Trans-Omics for Precision Medicine (TOPMed) cohort of >21,000 adults for SBP (PRS SBP ) to 4,297 AA Genetics of Hypertension Associated Treatment (GenHAT) participants randomized to CHL as part of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) with genome wide association study data. We then used linear regression to test the association of PRS SBP quintiles with CHL response (6 month BP - baseline BP) adjusting for age, sex, genetic ancestry, and baseline SBP. For the analysis of aTRH, cases were defined as individuals (a) treated with 3 different AHT classes, with average BP ≥140/90 mmHg at year 3 follow-up or (b) ≥4 AHT classes regardless of BP (cases, n=286). Treated controls were defined as individuals with BP <140/90 mmHg and on trial drug monotherapy at year 3 (n=2,391). Logistic regression models adjusting for age, sex, and genetic ancestry were used to calculate the odds ratio for aTRH comparing the highest and lowest quintile (Q5 and Q1, respectively).

Results: The PRS SBP was associated with reduced SBP response in Q5 (-5.01 [-6.15, -3.87] mmHg) versus Q1 (-8.24 [-9.39, -7.09] mmHg) and Q2 (-7.25 [-8.39, -6.11] mmHg). In regard to aTRH, Q5 was nominally associated with higher odds of aTRH compared to Q1 (1.48 [1.00, 2.20]).

Conclusions: We found that a general SBP PRS was associated with BP response in AAs from GenHAT. On average, a greater SBP reduction was found in participants at low genetic risk (Q1 or Q2) compared to the high risk (Q5) taking the same AHT. Similarly, when compared to participants in the bottom 20% of the distribution, those in the top 20% had increased odds of aTRH. Additional work using the PRS SBP in other ancestral populations, as well as developing novel AHT class treatment response PRS, is warranted and in progress to determine whether we can identify individuals who would benefit the most from specific AHT classes.

Pharmacogenomic Profiling of Pediatric Patients on Psychotropic Medications in an Emergency Department

OBJECTIVE

The aim of the study was to evaluate the ability of a combinatorial pharmacogenomic test to predict medication blood levels and relative clinical improvements in a selected pediatric population.

METHODS

This study enrolled patients between ages 3 to 18 years who presented to a pediatric emergency department with acute psychiatric, behavioral, or mental health crisis and/or concerns, and had previously been prescribed psychotropic medications. Patients received combinatorial pharmacogenomic testing with medications categorized according to gene-drug interactions (GDIs); medications with a GDI were considered "incongruent," and medications without a GDI were considered "congruent." Blood levels for escitalopram, fluoxetine, aripiprazole, and clonidine were evaluated according to level of GDI. Relative clinical improvements in response to the prescribed psychotropic medications were measured using a parent-rated Clinical Global Impression of Improvement (CGI-I) assessment, where lower scores corresponded with greater improvement.

RESULTS

Of the 100 patients enrolled, 73% reported taking ≥1 incongruent medication. There was no significant difference in CGI-I scores between patients prescribed congruent versus incongruent medications (3.37 vs 3.68, P = 0.343). Among patients who presented for depression or suicidal ideation, those prescribed congruent medications had significantly lower CGI-I scores compared with those taking incongruent medications ( P = 0.036 for depression, P = 0.018 for suicidal ideation). There was a significant association between medication GDI and blood levels for aripiprazole (n = 15, P = 0.01) and escitalopram (n = 10, P = 0.01).

CONCLUSIONS

Our preliminary findings suggest that combinatorial pharmacogenomic testing can predict medication blood levels and relative outcomes based on medication congruency in children presenting to an emergency department with acute psychiatric/behavioral crises. Additional studies will be needed to confirm these findings.

Risk of Postdischarge Bleeding From Dual Antiplatelet Therapy After Percutaneous Coronary Intervention Among US Black and White Adults

Background Dual antiplatelet therapy after percutaneous coronary intervention reduces myocardial infarctions but increases bleeding. The risk of bleeding may be higher among Black patients for unknown reasons. Bleeding risk scores have not been validated among Black patients. We assessed the difference in bleeding risk between Black and White patients along with the performance of the Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Anti Platelet Therapy, Patterns of Nonadherence to Antiplatelet Regimens in Stented Patients, and Academic Research Consortium for High Bleeding Risk scores among both groups. Methods and Results This was a single-center prospective study of patients who underwent percutaneous coronary intervention (2014-2019) and were followed for 1 year. The outcome was postdischarge Bleeding Academic Research Consortium 2 to 5 bleeding. Incidence rates were reported. Cox proportional hazards models measured the effect of self-reported Black race on bleeding and determined the predictors of bleeding among 19 a priori variables. The 3 risk scores were assessed among Black and White patients separately using the Harrell concordance index. Of 1529 included patients, 342 (22.4%) self-reported as being Black race. Unadjusted bleeding rates were 22.7 per 100 person-years among Black patients versus 16.3 among White patients (hazard ratio, 1.41 [95% CI, 1.00-2.00], P=0.052). Predictors of bleeding were age, glomerular filtration rate <30 mL/min per 1.73 m2, prior bleeding, ticagrelor or prasugrel use, and anticoagulant use. Among Black and White patients, respectively, the C-indexes were the following: 0.644 versus 0.600 for Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Anti Platelet Therapy (P<0.001 for both), 0.620 versus 0.612 for Patterns of Nonadherence to Antiplatelet Regimens in Stented Patients (P=0.003 and P<0.001, respectively), and 0.600 versus 0.598 for Academic Research Consortium for High Bleeding Risk (P=0.006 and P<0.001, respectively). Conclusions The risk of dual antiplatelet therapy-associated postdischarge Bleeding Academic Research Consortium 2 to 5 bleeding was not significantly different between self-reported Black and White patients. Bleeding risk scores performed similarly among both groups.

Outcomes of Individuals With and Without Heart Failure Presenting With Acute Coronary Syndrome

Major adverse cardiac event (MACE) and bleeding risks following percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) are not well defined in individuals with heart failure (HF). We followed 1,145 individuals in the Pharmacogenomic Resource to improve Medication Effectiveness Genotype Guided Antiplatelet Therapy cohort for MACE and bleeding events following PCI for ACS. We constructed Cox proportional hazards models to compare MACE and bleeding in those with versus without HF, adjusting for sociodemographics, comorbidities, and medications. We also determined predictors of MACE and bleeding events in both groups. 370 (32%) individuals did and 775 (68%) did not have HF prior to PCI. Mean age was 61.7 ± 12.2 years, 31% were female, and 24% were African American. After a median follow-up of 0.78 years, individuals with HF had higher rates of MACE compared to those without HF (48 vs. 24 events per 100 person years) which remained significant after multivariable adjustment (hazard ratio [HR] 1.31, 95% confidence interval [CI] 1.00 to 1.72). Similarly, bleeding was higher in those with versus without HF (22 vs. 11 events per 100 person years), although this was no longer statistically significant after multivariable adjustment (HR 1.29, 95% CI 0.86 to 1.93). Diabetes and peripheral vascular disease were predictors of MACE, and end-stage renal disease was a predictor of bleeding among participants with HF. MACE risk is higher in individuals with versus without HF following PCI for ACS. However, the risk of bleeding, especially among those with end-stage renal disease , must be considered when determining post-PCI anticoagulant strategies.

Residual risk for coronary heart disease events and mortality despite intensive medical management after myocardial infarction

BACKGROUND

High-intensity statins, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and antiplatelet agents (ie, intensive medical management) reduce coronary heart disease (CHD) risk after myocardial infarction (MI).

OBJECTIVE

The objective of the study was to determine the risk of CHD events or death despite receiving intensive medical management after MI.

METHODS

We studied 16,853 United States adults with health insurance in the MarketScan and Medicare databases who underwent percutaneous coronary intervention while hospitalized for MI between January 1, 2014 and June 30, 2015 and received intensive medical management within 30 days after hospital discharge. MI, CHD, and all-cause mortality rates from 30 days after hospital discharge through December 31, 2015 were compared with 67,412 individuals in each of three groups: (1) the general MarketScan and Medicare populations, (2) with diabetes, and (3) with a CHD history.

RESULTS

Among beneficiaries intensively medically managed after their MI, recurrent MI, CHD events, and all-cause mortality rates were 47.1, 72.0, and 57.5 per 1000 person-years, respectively. The multivariable-adjusted hazard ratio (95% CI) comparing intensively medically managed beneficiaries after MI to the general population, those with diabetes, and those with a history of CHD were 8.54 (7.52-9.70), 7.40 (6.61-8.28), and 5.45 (4.92-6.05), respectively, for recurrent MI; 7.82 (7.07-8.64), 6.27 (5.74-6.86), and 4.45 (4.10-4.82), respectively, for CHD events; and 1.15 (1.05-1.25), 1.05 (0.97-1.14), and 1.06 (0.97-1.15), respectively, for all-cause mortality.

CONCLUSION

Substantial residual risk for MI and CHD events remains despite intensive medical management after MI.

Genome-Wide Association Study of Apparent Treatment-Resistant Hypertension in the CHARGE Consortium: The CHARGE Pharmacogenetics Working Group

BACKGROUND

Only a handful of genetic discovery efforts in apparent treatment-resistant hypertension (aTRH) have been described.

METHODS

We conducted a case-control genome-wide association study of aTRH among persons treated for hypertension, using data from 10 cohorts of European ancestry (EA) and 5 cohorts of African ancestry (AA). Cases were treated with 3 different antihypertensive medication classes and had blood pressure (BP) above goal (systolic BP ≥ 140 mm Hg and/or diastolic BP ≥ 90 mm Hg) or 4 or more medication classes regardless of BP control (nEA = 931, nAA = 228). Both a normotensive control group and a treatment-responsive control group were considered in separate analyses. Normotensive controls were untreated (nEA = 14,210, nAA = 2,480) and had systolic BP/diastolic BP < 140/90 mm Hg. Treatment-responsive controls (nEA = 5,266, nAA = 1,817) had BP at goal (<140/90 mm Hg), while treated with one antihypertensive medication class. Individual cohorts used logistic regression with adjustment for age, sex, study site, and principal components for ancestry to examine the association of single-nucleotide polymorphisms with case-control status. Inverse variance-weighted fixed-effects meta-analyses were carried out using METAL.

RESULTS

The known hypertension locus, CASZ1, was a top finding among EAs (P = 1.1 × 10-8) and in the race-combined analysis (P = 1.5 × 10-9) using the normotensive control group (rs12046278, odds ratio = 0.71 (95% confidence interval: 0.6-0.8)). Single-nucleotide polymorphisms in this locus were robustly replicated in the Million Veterans Program (MVP) study in consideration of a treatment-responsive control group. There were no statistically significant findings for the discovery analyses including treatment-responsive controls.

CONCLUSION

This genomic discovery effort for aTRH identified CASZ1 as an aTRH risk locus.

Scalp EEG spikes predict impending epilepsy in TSC infants: A longitudinal observational study

Objective

To determine if routine electroencephalography (EEG) in seizure‐naive infants with tuberous sclerosis complex (TSC) can predict epilepsy and subsequent neurocognitive outcomes.

Methods

Forty infants 7 months of age or younger and meeting the genetic or clinical diagnostic criteria for tuberous sclerosis were enrolled. Exclusion criteria included prior history of seizures or treatment with antiseizure medications. At each visit, seizure history and 1‐hour awake and asleep video‐EEG, standardized across all sites, were obtained until 2 years of age. Developmental assessments (Mullen and Vineland‐II) were completed at 6, 12, and 24 months of age.

Results

Of 40 infants enrolled (mean age of 82.4 days), 32 completed the study. Two were lost to follow‐up and six were treated with antiepileptic drugs (AEDs) due to electrographic seizures and/or interictal epileptiform discharges (IEDs) on their EEG studies prior to the onset of clinical seizures. Seventeen of the 32 remaining children developed epilepsy at a mean age of 7.5 months (standard deviation [SD] = 4.4). Generalized/focal slowing, hypsarrhythmia, and generalized/focal attenuation were not predictive for the development of clinical seizures. Presence of IEDs had a 77.3% positive predictive value and absence a 70% negative predictive value for developing seizures by 2 years of age. IEDs preceded clinical seizure onset by 3.6 months (mean). Developmental testing showed significant decline, only in infants with ongoing seizures, but not infants who never developed seizures or whose seizures came under control.

Significance

IEDs identify impending epilepsy in the majority (77%) of seizure‐naive infants with TSC. The use of a 1‐hour awake and asleep EEG can be used as a biomarker for ongoing epileptogenesis in most, but not all, infants with TSC. Persistent seizures, but not history of interictal epileptiform activity or history of well‐controlled seizures, correlated with low scores on the Vineland and Mullen tests at 2 years of age.

Genome-wide meta-analysis of SNP and antihypertensive medication interactions on left ventricular traits in African Americans

BACKGROUND

Left ventricular (LV) hypertrophy affects up to 43% of African Americans (AAs). Antihypertensive treatment reduces LV mass (LVM). However, interindividual variation in LV traits in response to antihypertensive treatments exists. We hypothesized that genetic variants may modify the association of antihypertensive treatment class with LV traits measured by echocardiography.

METHODS

We evaluated the main effects of the three most common antihypertensive treatments for AAs as well as the single nucleotide polymorphism (SNP)-by-drug interaction on LVM and relative wall thickness (RWT) in 2,068 participants across five community-based cohorts. Treatments included thiazide diuretics (TDs), angiotensin converting enzyme inhibitors (ACE-Is), and dihydropyridine calcium channel blockers (dCCBs) and were compared in a pairwise manner. We performed fixed effects inverse variance weighted meta-analyses of main effects of drugs and 2.5 million SNP-by-drug interaction estimates.

RESULTS

We observed that dCCBs versus TDs were associated with higher LVM after adjusting for covariates (p = 0.001). We report three SNPs at a single locus on chromosome 20 that modified the association between RWT and treatment when comparing dCCBs to ACE-Is with consistent effects across cohorts (smallest p = 4.7 × 10-8 , minor allele frequency range 0.09-0.12). This locus has been linked to LV hypertrophy in a previous study. A marginally significant locus in BICD1 (rs326641) was validated in an external population.

CONCLUSIONS

Our study identified one locus having genome-wide significant SNP-by-drug interaction effect on RWT among dCCB users in comparison to ACE-I users. Upon additional validation in future studies, our findings can enhance the precision of medical approaches in hypertension treatment.

Clinical and Genetic Predictors of Delayed Remission After Multiple Levels of Antidepressant Treatment: Toward Early Identification of Depressed Individuals for Advanced Care Options

OBJECTIVE

To identify clinical and genetic characteristics that can be used to recognize depressed patients who are likely to respond quickly versus those who will have a more delayed response following multiple treatment trials.

METHODS

The data used were obtained from the National Institute of Mental Health-sponsored Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, which was conducted between July 2001 and September 2006. Of the 4,041 treatment-naive participants in the original study, 1,953 with DNA samples were included. Major depressive disorder (DSM-IV criteria) was defined as baseline score > 14 on the 17-item Hamilton Depression Rating Scale. Time to remission was defined from the entry point to when a score ≤ 5 on the Quick Inventory of Depressive Symptomatology, Clinician Rating was achieved, irrespective of the type or number of treatments received. A Kaplan-Meier estimator was used for data description, proportional hazard regression for model building, and logistic regression for measures of predictive accuracy.

RESULTS

The overall rate of remission across all levels of treatment was 65.6%, and the overall median (interquartile range) of time to remission was 11.4 (6.0-17.9) weeks. The predictors of delayed remission included unemployment (P = .004), severe medical comorbidity (P < .0001), severe baseline depression (P < .0001), more than 4 dysthymic symptoms (P = .005), more than 9 posttraumatic stress symptoms (P = .005), and serotonin receptor 1A (P = .006) and cytochrome P450 2D6 (P = .002 for C/T and P = .0004 for T/T) genetic variants. The final model had good predictive measures of accuracy of area under the curve (70%) and sensitivity (88%).

CONCLUSIONS

The results offer clinical tools for clinicians to identify depressed individuals who are likely to have delayed remission with multiple antidepressant treatments and therefore might be candidates for advanced care options.

A PheWAS study of a large observational epidemiological cohort of African Americans from the REGARDS study

BACKGROUND

Cardiovascular disease, diabetes, and kidney disease are among the leading causes of death and disability worldwide. However, knowledge of genetic determinants of those diseases in African Americans remains limited.

RESULTS

In our study, associations between 4956 GWAS catalog reported SNPs and 67 traits were examined among 7726 African Americans from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, which is focused on identifying factors that increase stroke risk. The prevalent and incident phenotypes studied included inflammation, kidney traits, cardiovascular traits and cognition. Our results validated 29 known associations, of which eight associations were reported for the first time in African Americans.

CONCLUSION

Our cross-racial validation of GWAS findings provide additional evidence for the important roles of these loci in the disease process and may help identify genes especially important for future functional validation.

Racial disparities in temporal lobe epilepsy

OBJECTIVE

This study reports on epilepsy type period prevalence and black-white racial differences in a large patient population in the Southeastern United States.

METHODS

For all patients visiting the University of Alabama at Birmingham's seizure monitoring unit between 2000 and 2011 (n = 3240), video EEG diagnosis was recorded along with basic demographic information. Descriptive statistics and multivariate logistic regression were used to identify factors associated with temporal lobe epilepsy (TLE) diagnosis.

RESULTS

The racial distribution was 77.3% white, and 20.0% black (other races were only 2.3% of the population). Most patients had either TLE (n = 630) or PNES (n = 1150) compared to other focal (n = 424) or generalized epilepsies (n = 224). The diagnosis of TLE was significantly greater for blacks than whites (odds ratio [OR] = 1.87, 95% confidence interval [CI] 1.47-2.37). The period prevalence measures for the other conclusively diagnosed epilepsies were not significantly different. Women were disproportionately represented in the study population, and black women carried the most statistical weight for the TLE prevalence difference.

INTERPRETATION

The nearly two-fold larger period prevalence of TLE among black patients is a striking finding that merits explanation. Although some selection bias exists due to a moderately lower than expected representation of blacks, socioeconomic status or access to care should not be assumed to be the only factors that might be responsible for the prevalence difference. Rather, all clues for distinct pathophysiological racial differences should be explored.

Pharmacogenetics in Cardiovascular Medicine

PURPOSE OF REVIEW

Pharmacogenetics is an important component of precision medicine. Even within the genomic era, several challenges lie ahead in the road towards clinical implementation of pharmacogenetics in the clinic. This review will summarize the current state of knowledge regarding pharmacogenetics of cardiovascular drugs, focusing on those with the most evidence supporting clinical implementation- clopidogrel, warfarin and simvastatin.

RECENT FINDINGS

There is limited translation of pharmacogenetics into clinical practice primarily due to the absence of outcomes data from prospective, randomized, genotype-directed clinical trials. There are several ongoing randomized controlled trials that will provide some answers as to the clinical utility of genotype-directed strategies. Several academic medical centers have pushed towards clinical implementation where the clinical validity data are strong. Their experiences will inform operational requirements of a clinical pharmacogenetics testing including the timing of testing, incorporation of test results into the electronic health record, reimbursement and ethical issues.

SUMMARY

Pharmacogenetics of clopidogrel, warfarin and simvastatin are three examples where pharmacogenetics testing may provide added clinical value. Continued accumulation of evidence surrounding clinical utility of pharmacogenetics markers is imperative as this will inform reimbursement policy and drive adoption of pharamcogenetics into routine care.

Age and Sex Disparities in Discharge Statin Prescribing in the Stroke Belt: Evidence From the Reasons for Geographic and Racial Differences in Stroke Study

BACKGROUND

Stroke is a costly and debilitating disease that disproportionately affects blacks. Despite the efficacy of statins, evidence suggests racial disparities may exist in statin prescribing.

METHODS AND RESULTS

We analyzed discharge medications for participants hospitalized for an ischemic stroke during follow-up of the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study. Medications on admission and discharge were abstracted from medical records. Among the 666 eligible incident strokes (2003-2013), analyses were restricted to 323 participants who were not statin users at the time of admission and had no history of atrial fibrillation. Overall, 48.7% were prescribed a statin on discharge. In the Stroke Belt, participants aged 65 years and older were 47% less likely to be discharged on a statin compared with those younger than 65 years (relative risk [RR], 0.53; 95% CI, 0.38-0.74). This association was not observed in non-Stroke Belt residents. Outside the Stroke Belt, blacks were more likely than whites to be discharged on a statin (RR, 1.42; 95% CI, 1.04-1.94), while no black:white association was present among Stroke Belt residents (RR, 0.93; 95% CI, 0.69-1.26; P for interaction=0.228). Compared with women, men in the Stroke Belt were 31% less likely to be discharged on a statin (RR, 0.69; 95% CI, 0.50-0.94) while men outside the Stroke Belt were more likely to be discharged on a statin (RR, 1.38; 95% CI, 0.99-1.92; P for interaction=0.004).

CONCLUSIONS

Statin discharge prescribing may differ among Stroke Belt and non-Stroke Belt residents, particularly in older Americans and men.

Whole exome analyses to examine the impact of rare variants on left ventricular traits in African American participants from the HyperGEN and GENOA studies

Left ventricular (LV) hypertrophy, highest in prevalence among African Americans, is an established risk factor heart failure. Several genome wide association studies have identified common variants associated with LV-related quantitative-traits in African Americans. To date, however, the effect of rare variants on these traits has not been extensively studied, especially in minority groups. We therefore investigated the association between rare variants and LV traits among 1,934 African Americans using exome chip data from the Hypertension Genetic Epidemiology Network (HyperGEN) study, with replication in 1,090 African American from the Genetic Epidemiology Network of Arteriopathy (GENOA) study. We used single-variant analyses and gene-based tests to investigate the association between 86,927 variants and six structural and functional LV traits including LV mass, LV internal dimension-diastole, relative wall thickness, left atrial dimension (LAD), fractional shortening (FS), and the ratio of LV early-to-late transmitral velocity (E/A ratio). Only rare variants (MAF <1% and <5%) were considered in gene-based analyses. In gene-based analyses, we found a statistically significant association between potassium voltage-gated channel subfamily H member 4 (KCNH4) and E/A ratio (P=8.7*10^-8 using a burden test). Endonuclease G (ENDOG) was associated with LAD using the Madsen Browning weighted burden (MB) test (P=1.4*10^-7). Neither gene result was replicated in GENOA, but the direction of effect of single variants in common was comparable. G protein-coupled receptor 55 (GPR55) was marginally associated with LAD in HyperGEN (P=3.2*10^-5 using the MB test) and E/A ratio in GENOA, but with opposing directions of association for variants in common (P=0.03 for the MB test). No single variant was statistically significantly associated with any trait after correcting for multiple testing. The findings in this study highlight the potential cumulative contributions of rare variants to LV traits which, if validated, could improve our understanding of heart failure in African Americans.

Influence of statin therapy at time of stroke onset on functional outcome among patients with atrial fibrillation

BACKGROUND

Statin pretreatment has been associated with reduced infarct volume in nonlacunar strokes. The effect of statins on functional outcomes of strokes related to atrial fibrillation (AF) is unknown. We aimed to define the influence of prestroke statin use on functional outcome in AF.

METHODS

We assembled a cohort of consecutive ischemic stroke patients from 2006 to 2010. All patients underwent CT or MRI and were adjudicated by site investigators. AF was confirmed by electrocardiogram in 100% of patients. Site neurologists blinded to the study hypothesis affirmed the type of stroke and assessed the severity of disability at the time of hospital discharge. The frequency of death at 30-days was calculated.

RESULTS

Ischemic stroke (n=1030) resulted in a severe neurological deficit or death (modified Rankin scale ≥4) at 30days in 711 patients (69%). Using multivariable logistic regression models adjusting for factors associated with statin treatment and factors associated with functional outcome, prestroke statin use was associated with a 32% reduction in frequency of severe stroke (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.50-0.92; P=0.011). Other independent factors associated with severe stroke included older age, female sex, non-White race, diabetes mellitus, prior ischemic stroke, prior venous thromboembolism, and dementia.

CONCLUSION

Ischemic strokes in AF are associated with high mortality and morbidity. Statin use at time of stroke onset among patients with AF was associated in this study with less severe stroke and warrant validation.

Abstract WP416: African Americans are Less Likely to be Adherent to Statins After Ischemic Stroke: an Analysis of Medicare Beneficiaries Following Hospital Discharge

Introduction: Statins have been shown to decrease cardiovascular disease morbidity and mortality. Although statins have proven efficacious in reducing the risk of recurrent stroke, little is known about adherence among older adults following ischemic stroke.

Methods: We compiled a retrospective cohort of Caucasian and African-American Medicare beneficiaries in the 5% sample to estimate statin adherence among older adults initiating therapy following hospitalization for ischemic stroke in 2007 - 2011. To be included, beneficiaries were required to have 365 days of Medicare fee-for-service coverage with no claims for stroke-related events or statins prior to the index stroke event. The cohort was limited to beneficiaries with an initial Part D claim for a statin within 30 days plus at least 1 additional claim during follow-up. Adherence was determined by percent of days covered (PDC) for the 365 days following discharge home (time spent in rehabilitation or skilled nursing was excluded); non-adherence was defined as a PDC <80%. Relative risk of statin non-adherence was determined using modified Poisson regression.

Results: Among 6,251 statin-naïve beneficiaries with stroke, 2,070 (33.1%) initiated statin therapy and were included in the analysis. Among them, 13.1% (n=271) were African American. African Americans were more likely than Caucasians to have a PDC <80%, 15.4% vs. 11.7%, respectively (crude RR 1.21, 95% CI 1.04-1.40). The racial disparity remained after adjusting for demographics, dual Medicare-Medicaid eligibility, and baseline comorbidities (adjusted RR 1.17, 95% CI 0.99-1.37).

Conclusions: African Americans may not be obtaining the recurrent stroke prevention therapy provided by statins, possibly contributing to the higher rate of recurrent stroke in this population.

Addressing Stroke Risk Factors in Black and White Americans: Findings from the National Health and Nutrition Examination Survey, 2009-2010

OBJECTIVE

Recurrent stroke affects 5%-15% of stroke survivors, is higher among Blacks, and preventable with secondary stroke prevention medications. Our study aimed to examine racial differences in risk factors being addressed (defined as either on active treatment or within guideline levels) among stroke survivors and those at risk for stroke.

METHODS

A cross-sectional study using NHANES 2009-2010 standardized interviews of Whites and Blacks aged ≥18 years. Risk factors were defined as being addressed if: 1) for hypertension, SBP <140, DBP <90 (SBP<130, DBP<80 for diabetics) or using BP-lowering medications; 2) for current smoking, using cessation medications; and 3) for hyperlipidemia, LDL<100 (LDL<70 for stroke survivors) or using lipid-lowering medications. Participants were stratified by stroke history. Prevalence of addressed risk factors was compared by race.

RESULTS

Among 4005 participants (mean age 48, 52% women, 15% Black), 4% reported a history of stroke. Among stroke survivors, there were no statistically significant differences in Blacks and Whites having their hypertension or hyperlipidemia addressed. Among stroke naïve participants, the prevalence of addressed hypertension (P<.01) and hyperlipidemia (P<.01) was lower in Blacks compared with Whites.

CONCLUSIONS

We found that addressed hypertension and hyperlipidemia in stroke naïve participants were significantly lower in Blacks than Whites. Our observations call attention to areas that require further investigation, such as why Black Americans may not be receiving evidence-based pharmacologic therapy for hypertension and hyperlipidemia or why Black Americans are not at goal blood pressure or goal LDL. A better understanding of this information is critical to preventing stroke and other vascular diseases.

APOL1 nephropathy risk variants are associated with altered high-density lipoprotein profiles in African Americans

BACKGROUND

Two independent coding variants in the apolipoprotein L1 gene (APOL1), G1 and G2, strongly associate with nephropathy in African Americans; associations with cardiovascular disease are more controversial. Although APOL1 binds plasma high-density lipoproteins (HDLs), data on APOL1 risk variant associations with HDL subfractions are sparse.

METHODS

Two APOL1 G1 single nucleotide polymorphisms and the G2 insertion/deletion polymorphism were genotyped in 2010 Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study participants with nuclear magnetic resonance spectroscopy-based lipoprotein subfraction measurements. Linear regression was used to model associations between numbers of APOL1 G1/G2 risk variants and HDL subfractions, adjusting for demographic, clinical and ancestral covariates.

RESULTS

Female sex and higher percentage of African ancestry were positively associated with the number of APOL1 G1/G2 risk alleles. In the unadjusted analysis, mean (standard error) small HDL concentrations (μmol/L) for participants with zero, one and two G1/G2 risk alleles were 19.0 (0.2), 19.7 (0.2) and 19.9 (0.4), respectively (P = 0.02). Adjustment for age, sex, diabetes and African ancestry did not change the results but strengthened the statistical significance (P = 0.004). No significant differences in large or medium HDL, very low-density lipoprotein or low-density lipoprotein particle concentrations were observed by APOL1 genotype.

CONCLUSIONS

Greater numbers of APOL1 G1/G2 risk alleles were associated with higher small HDL particle concentrations in African Americans. These results may suggest novel areas of investigation to uncover reasons for the association between APOL1 risk variants with adverse outcomes in African Americans.

Abstract 179: Ischemic Stroke in Atrial Fibrillation: 30-day Outcomes and Factors Associated with Severity

Background and Hypothesis: Ischemic stroke (IS) in atrial fibrillation (AF) is associated with high mortality. Inflammation, endothelial dysfunction, and hypercoagulability, in addition to blood stasis in the left atrium, play a critical role in thrombogenesis in AF. Hyperglycemia and chronic kidney disease (CKD) are potent triggers for inflammation, oxidative stress, and thrombogenesis. Statins have been shown to possess anti-inflammatory, anti-oxidant, and anti-thrombotic properties. Accordingly, we assessed the hypothesis that statin use may modulate stroke severity in AF.

Methods: Consecutive IS admissions were identified from 2006-2010. All events were subject to CT or MRI and assessed for functional independence at discharge using modified Rankin scale (mRS). AF was confirmed by ECG at presentation or within the prior 6 months in all cases. Covariates were abstracted from the medical record. To account for confounding by treatment, we used multivariable logistic regression analysis adjusted using inverse probability weighting.

Results: We identified 1,030 AF-related IS; mean age was 77, 56% were female, mean CHA 2 DS 2 VASC score was 4.8 designating high baseline stroke risk. IS resulted in severe neurological deficit or death (mRS ≥ 4) for 69%; 21% died within 30-days. Severe stroke was associated with older age, diabetes, dementia, prior ischemic stroke, prior venous thromboembolism, and CKD (Table). Baseline statin use was associated with a 33% reduced risk of sustaining a severe stroke.

Conclusion: Strokes in AF are associated with high morbidity and mortality. Clinical markers of thrombophilia, including prior IS, DVT, and PE, were significantly associated with severe strokes. Diabetes and CKD independently increased this risk. Statin use resulted in less severe outcomes. Advancing our basic understanding of these interrelated thrombogenic pathways will inform clinical interventions to reduce these devastating outcomes.

Abstract T MP44: Secondary Stroke Prevention Prescribing in a National Cohort

Background and Purpose: Secondary stroke prevention medications (SSPs) have been shown to prevent recurrent stroke, but few national reports of prescribing SSPs are available from hospitals regardless of their participation in national quality improvement programs. We examined SSP prescribing at discharge following hospitalization for adjudicated incident ischemic stroke (IS) in a large national cohort and unselected hospitals.

Methods: We performed a retrospective review of incident IS admissions within the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort; admissions were to unselected hospitals. Exclusions were history of stroke, hospital death, missing data, and prevalent use of the medication of interest. Race, sex, age, rurality of residence (as defined by Rural Urban Commuting Area codes) were obtained at REGARDS baseline. Admission and discharge medications were obtained from hospital records. Associations between characteristics and discharge SSP prescriptions were examined using logistic regression adjusting for race, age, sex, and rurality.

Results: From 2003-2011, of 657 IS, 429 met inclusion criteria. Mean age of participants was 73 (42% Black, 49% female, 27% non-urban). Antithrombotic therapy (antiplatelet/anticoagulant) was prescribed for 87%, statins 36% (10% 80mg), and ACE-I/ARB for 16%. We observed no statistically significant differences in prescribing antithrombotics or statins by race, sex, age, or rurality. Participants in non-urban areas had lower odds of ACE-I/ARB at discharge (OR 0.38, 0.15-0.98), with no differences by race, sex, or age.

Conclusions: The majority of participants with incident IS within REGARDS were newly prescribed antithrombotics at discharge but alarmingly few were newly prescribed statins or ACE-I/ARBs. Our findings among incident SSP users differ from previous reports among prevalent users within hospitals participating in a national quality improvement program. More studies of quality of care after IS at unselected hospitals are needed.

Genetic variant in folate homeostasis is associated with lower warfarin dose in African Americans

The anticoagulant warfarin has >30 million prescriptions per year in the United States. Doses can vary 20-fold between patients, and incorrect dosing can result in serious adverse events. Variation in warfarin pharmacokinetic and pharmacodynamic genes, such as CYP2C9 and VKORC1, do not fully explain the dose variability in African Americans. To identify additional genetic contributors to warfarin dose, we exome sequenced 103 African Americans on stable doses of warfarin at extremes (≤ 35 and ≥ 49 mg/week). We found an association between lower warfarin dose and a population-specific regulatory variant, rs7856096 (P = 1.82 × 10(-8), minor allele frequency = 20.4%), in the folate homeostasis gene folylpolyglutamate synthase (FPGS). We replicated this association in an independent cohort of 372 African American subjects whose stable warfarin doses represented the full dosing spectrum (P = .046). In a combined cohort, adding rs7856096 to the International Warfarin Pharmacogenetic Consortium pharmacogenetic dosing algorithm resulted in a 5.8 mg/week (P = 3.93 × 10(-5)) decrease in warfarin dose for each allele carried. The variant overlaps functional elements and was associated (P = .01) with FPGS gene expression in lymphoblastoid cell lines derived from combined HapMap African populations (N = 326). Our results provide the first evidence linking genetic variation in folate homeostasis to warfarin response.

Integration of genetic, clinical, and INR data to refine warfarin dosing

Well-characterized genes that affect warfarin metabolism (cytochrome P450 (CYP) 2C9) and sensitivity (vitamin K epoxide reductase complex 1 (VKORC1)) explain one-third of the variability in therapeutic dose before the international normalized ratio (INR) is measured. To determine genotypic relevance after INR becomes available, we derived clinical and pharmacogenetic refinement algorithms on the basis of INR values (on day 4 or 5 of therapy), clinical factors, and genotype. After adjusting for INR, CYP2C9 and VKORC1 genotypes remained significant predictors (P < 0.001) of warfarin dose. The clinical algorithm had an R(2) of 48% (median absolute error (MAE): 7.0 mg/week) and the pharmacogenetic algorithm had an R(2) of 63% (MAE: 5.5 mg/week) in the derivation set (N = 969). In independent validation sets, the R(2) was 26-43% with the clinical algorithm and 42-58% when genotype was added (P = 0.002). After several days of therapy, a pharmacogenetic algorithm estimates the therapeutic warfarin dose more accurately than one using clinical factors and INR response alone.

Effect of epilepsy magnetic source imaging on intracranial electrode placement

OBJECTIVE

Intracranial electroencephalography (ICEEG) with chronically implanted electrodes is a costly invasive diagnostic procedure that remains necessary for a large proportion of patients who undergo evaluation for epilepsy surgery. This study was designed to evaluate whether magnetic source imaging (MSI), a noninvasive test based on magnetoencephalography source localization, can supplement ICEEG by affecting electrode placement to improve sampling of the seizure onset zone(s).

METHODS

Of 298 consecutive epilepsy surgery candidates (between 2001 and 2006), 160 patients were prospectively enrolled by insufficient localization from seizure monitoring and magnetic resonance imaging results. Before presenting MSI results, decisions were made whether to proceed with ICEEG, and if so, where to place electrodes such that the hypothetical seizure-onset zone would be sampled. MSI results were then provided with allowance of changes to the original plan.

RESULTS

MSI indicated additional electrode coverage in 18 of 77 (23%) ICEEG cases. In 39% (95% confidence interval, 16.4-61.4), seizure-onset ICEEG patterns involved the additional electrodes indicated by MSI. Sixty-two patients underwent surgical resection based on ICEEG recording of seizures. Highly localized MSI was significantly associated with seizure-free outcome (mean, 3.4 years; minimum, >1 year) for the entire surgical population (n = 62).

INTERPRETATION

MSI spike localization increases the chance that the seizure-onset zone is sampled when patients undergo ICEEG for presurgical epilepsy evaluations. The clinical impact of this effect, improving diagnostic yield of ICEEG, should be considered in surgery candidates who do not have satisfactory indication of epilepsy localization from seizure semiology, electroencephalogram, and magnetic resonance imaging.

Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update

Obesity is a major health problem facing the developed and developing world. Efforts by individuals, health professionals, educators, and policy makers to combat the escalating trend of growing obesity prevalence have been multifaceted and mixed in outcome. Various dietary supplements have been marketed to reduce obesity. These products have been suggested to accomplish this by decreasing energy intake and energy absorption, and/or increasing metabolic rate. Ephedra, one such supplement, was banned from sale in the US market because of concerns about adverse events. Another substance, Citrus aurantium, which contains several compounds including synephrine alkaloids, has been suggested as a safe alternative. This review examines the evidence for safety and efficacy of C. aurantium and synephrine alkaloids as examined in animal studies, clinical weight loss trials, acute physiologic studies and case reports. Although at least three reviews of C. aurantium have been published, our review expands upon these by: (i) distinguishing and evaluating the efficacy of C. aurantium and related compounds; (ii) including results from previously unreviewed research; (iii) incorporating recent case reports that serve to highlight, in an anecdotal way, potential adverse events related to the use of C. aurantium and related compounds; and (iv) offering recommendations to guide the design of future trials to evaluate the safety and efficacy of C. aurantium. While some evidence is promising, we conclude that larger and more rigorous clinical trials are necessary to draw adequate conclusions regarding the safety and efficacy of C. aurantium and synephrine alkaloids for promoting weight loss.

Neurotoxicity following addition of intravenous valproate to lamotrigine therapy

Reversible neurotoxic symptoms were observed in three adult patients with absence status epilepticus on lamotrigine (LTG) therapy after administration of an IV bolus followed by oral valproic acid (VPA). Neurotoxicity was likely related to elevated serum LTG levels, as improvement correlated with discontinuing or reducing LTG dosage.

Rasmussen's Encephalitis

When the diagnosis of Rasmussen's encephalitis is being considered, it is important to rapidly exclude other causes of epilepsia partialis continua and hemiparesis. Although there is no good data from randomized trials of different immune-related therapies, treatment with immunoglobulin G (IgG), steroids, or plasmapheresis is advocated as first-line therapy. It is not unreasonable to institute at least two treatment options (eg, IgG followed by plasmapheresis) if response to the first treatment is poor. Functional hemispherectomy and its variants are associated with a lower long-term complication rate.