Detection of Subclinical Cardiac Dysfunction in Patients With Sickle Cell Disease Using Speckle-Tracking Echocardiography

Sickle cell disease (SCD) is characterized by chronic anemia and recurrent ischemia-reperfusion episodes, which can lead to high-output heart failure. The impact of SCD on cardiac structure and function remains underinvestigated. We conducted a single-institution retrospective analysis of clinical and echocardiographic data from patients with hemoglobin SS SCD (SCD-SS) between January 2016 and June 2022. Patients with known heart failure, left ventricular (LV) ejection fraction <50%, moderate or severe valvular heart disease, congenital heart disease, established coronary artery disease, diabetes mellitus, hypertension, or coexistent lung disease were excluded. Compared with healthy controls (n = 28), patients with SCD-SS (n = 66) had a significantly higher left atrial (LA) volume index (35.7 vs 23.9 ml/m², p <0.001) and average E/e' (7.4 vs 6.5, p = 0.003) but lower average e' (12.3 vs 13.6 cm/s, p = 0.047) and LA reservoir strain (32.9% vs 42.4%, p <0.001). Patients with SCD-SS had higher LV end-diastolic (132.5 vs 104.1 ml, p <0.001) and LV end-systolic volumes (51.0 vs 43.8 ml, p = 0.017) with reduced LV global longitudinal strain (17.6% vs 20.0%, p <0.001). In addition, patients with SCD-SS showed reduced right ventricular (RV) global longitudinal strain (19.7% vs 22.8%, p <0.001) in the setting of normal RV tricuspid annular plane systolic excursion. Maximal systolic tricuspid regurgitation velocity (231 vs 202 cm/s, p <0.001) and right atrial area (16.6 vs 12.8 cm², p <0.001) were statistically greater in SCD-SS. Hemoglobin and hematocrit negatively correlated with LA volume index, average E/e', LV end-diastolic and LV end-systolic volumes. In conclusion, patients with SCD-SS had notable differences in cardiac chamber size and impaired LV, RV, and LA strain compared with healthy controls. Further investigations are needed to assess the impact of these variables on SCD clinical course and prognosis.

Electrocardiographic findings in patients with sickle cell disease: A protocol for systematic review and meta-analysis

Background

Despite advancements in the management of patients with sickle cell disease (SCD), the involvement of the cardiovascular system in these patients remains a significant concern. Cardiovascular manifestations of SCD are well-documented, with electrocardiography (ECG) serving as a valuable diagnostic tool. Studies have reported a high rate of critical ECG findings in patients with SCD that warrants consideration when managing these patients, indicating the need for proactive cardiac screening and management strategies in this patient population. This study aims to systematically review the literature to identify sociodemographic, clinical, and paraclinical factors associated with ECG abnormalities in patients with SCD.

Methods

A comprehensive search strategy will be employed across multiple online databases, including PubMed, Embase, Scopus, Web of Science, and Google Scholar, for published and gray literature. Eligible studies will include original articles reporting associations between sociodemographic, clinical, and paraclinical variables and a spectrum of ECG findings in patients with SCD. Independent reviewers will conduct the screening, quality assessment, and data extraction. Quantitative analyses will be performed under a random-effect model using Comprehensive Meta-Analysis software, with subgroup analyses based on SCD status, sickle hemoglobinopathy form, and age group.

Electrocardiographic abnormalities in patients with sickle cell disease: A systematic review and meta-analysis

BACKGROUND

Previous studies have documented that electrocardiography (ECG) can reveal a range of abnormalities, offering valuable insights into the cardiac evaluation of patients with sickle cell disease (SCD). The objective of this study is to assess the patterns of ECG abnormalities observed in these patients with SCD, and to determine their prevalence.

METHOD

We systematically reviewed the literature using online databases of PubMed, Scopus, Web of Science, Embase, and Google Scholar to identify original studies that reported findings of standard ECG assessments in patients with SCD. Statistical analyses were performed using the random effects model. Additional analyses including sensitivity analysis and subgroup analysis were also conducted.

RESULTS

Analysis of data from 59 studies involving 897,920 individuals with SCD revealed that 75% of these patients had abnormal ECG findings (67%-81%), which were predominantly nonspecific ST-T changes, left ventricular hypertrophy, T-wave changes, prolonged corrected QT (QTc) interval, and ischemic changes. Besides, it was shown that these patients had significantly higher odds of having any ECG abnormalities (OR of 17.50, 4.68-65.49), right atrial enlargement (6.09, 1.48-25.09), left ventricular hypertrophy (3.45, 1.73-6.89), right ventricular hypertrophy (7.18, 2.28-22.57), biventricular hypertrophy (10.11, 1.99-51.38), prolonged QTc interval (5.54, 2.44-12.59), ST depression (3.34, 1.87-5.97), and T-wave changes (5.41, 1.43-20.56). Moreover, the mean of QTc interval was significantly higher among those with SCD (23.51 milliseconds, 16.08-30.94).

CONCLUSION

Our meta-analysis showed a higher prevalence of abnormal ECG findings among individuals with SCD. A significant proportion of these patients had various ECG abnormalities, suggesting a potential need for regular ECG assessments for patients with SCD.

Genetic variants and effect modifiers of QT interval prolongation in patients with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is a common inherited blood disorder among African Americans (AA), with premature mortality which has been associated with prolongation of the heart rate-corrected QT interval (QTc), a known risk factor for sudden cardiac death. Although numerous genetic variants have been identified as contributors to QT interval prolongation in the general population, their impact on SCD patients remains unclear. This study used an unweighted polygenic risk score (PRS) to validate the previously identified associations between SNPs and QTc interval in SCD patients, and to explore possible interactions with other factors that prolong QTc interval in AA individuals with SCD.

METHODS

In SCD patients, candidate genetic variants associated with the QTc interval were genotyped. To identify any risk SNPs that may be correlated with QTc interval prolongation, linear regression was employed, and an unweighted PRS was subsequently constructed. The effect of PRS on the QTc interval was evaluated using linear regression, while stratification analysis was used to assess the influence of serum alanine transaminase (ALT), a biomarker for liver disease, on the PRS effect. We also evaluated the PRS with the two subcomponents of QTc, the QRS and JTc intervals.

RESULTS

Out of 26 candidate SNPs, five risk SNPs were identified for QTc duration under the recessive model. For every unit increase in PRS, the QTc interval prolonged by 4.0 ms (95% CI: [2.0, 6.1]; p-value: <0.001) in the additive model and 9.4 ms in the recessive model (95% CI: [4.6, 14.1]; p-value: <0.001). Serum ALT showed a modification effect on PRS-QTc prolongation under the recessive model. In the normal ALT group, each PRS unit increased QTc interval by 11.7 ms (95% CI: [6.3, 17.1]; p-value: 2.60E-5), whereas this effect was not observed in the elevated ALT group (0.9 ms; 95% CI: [-7.0, 8.8]; p-value: 0.823).

CONCLUSION

Several candidate genetic variants are associated with QTc interval prolongation in SCD patients, and serum ALT acts as a modifying factor. The association of a CPS1 gene variant in both QTc and JTc duration adds to NOS1AP as evidence of involvement of the urea cycle and nitric oxide metabolism in cardiac repolarization in SCD. Larger replication studies are needed to confirm these findings and elucidate the underlying mechanisms.

Clinical and Laboratory Correlates of QTc Duration in Adult and Pediatric Sickle Cell Disease

Background

Sickle cell disease, a common genetic disorder in African Americans, manifests an increased risk of sudden death, the basis of which is incompletely understood. Prolongation of heart rate-corrected QT (QTc) interval on the electrocardiogram, a standard clinical measure of cardiac repolarization, may contribute to sudden death by predisposing to torsades de pointes ventricular tachycardia.

Methods

We established a cohort study of 293 adult and 121 pediatric sickle cell disease patients drawn from the same geographic region as the Jackson Heart Study (JHS) cohort, in which significant correlates of QT duration have been characterized and quantitatively modeled. Herein, we establish clinical and laboratory correlates of QTc duration in our cohort using stepwise multivariate linear regression analysis. We then compared our adult sickle cell disease data to effect-size predictions from the published JHS statistical model of QT interval duration.

Results

In adult sickle cell disease, gender, diuretic use, QRS duration, serum ALT levels, anion gap, and diastolic blood pressure show positive correlation; hemoglobin levels show inverse correlation; in pediatric sickle cell disease, age, hemoglobin levels, and serum bicarbonate and creatinine levels show inverse correlation. The mean QTc in our adult sickle cell disease cohort is 7.8 milliseconds longer than in the JHS cohort, even though the JHS statistical model predicts that the mean QTc in our cohort should be > 11 milliseconds shorter than in the much older JHS cohort, a differential of > 18 milliseconds.

Conclusion

Sickle cell disease patients have substantial QTc prolongation relative to their age, driven by factors some overlapping, in adult and pediatric sickle cell disease, and distinct from those that have been defined in the general African American community.

The Prevalence of Cardiovascular Manifestations in Pediatric Sickle Cell Anemia Patients in a Large Tertiary Care Hospital in the Western Region of Saudi Arabia

Background Sickle cell disease (SCD) is a common hematological disorder with a high prevalence in Saudi Arabia. Despite that, limited studies are available in our region regarding cardiovascular complications. Objectives The objective of the current study was to estimate the prevalence of cardiovascular complications among children with SCD. Design This was a cross-sectional study. Setting The study took place at a single tertiary-care center in Jeddah, Saudi Arabia. Materials and methods The study reviewed 126 electronic records of pediatric patients up to 16 years old diagnosed with SCD between January 2008 and December 2019 in King Abdulaziz Medical City (KAMC) in Jeddah, Saudi Arabia. Of these, 54 patients had a previous echocardiogram evaluation and were eligible for the study. Main outcomes measures The study identified cardiovascular complications in pediatric sickle cell patients. Sample size The study included a total of 54 pediatric sickle cell patients. Results The mean age was 11.9 (3.48) years, the male-to-female ratio was 2:1, the majority (94.4%) had the HbSS-HbSβ0 genotype, the mean baseline hemoglobin F (fetal hemoglobin) was 20.30 (9.03%), and the clinical severity score was severe in 19 (35.2%) and mild/moderate in 35 (64.8%) patients. Cardiovascular complications occurred in 32 (59.3%) patients. Increased systolic blood pressure was detected in 10 (18.5%) patients. Echocardiography showed left ventricular dilatation in nine (16.7%) patients, tricuspid valve insufficiency in six (11.1%) patients, mitral valve insufficiency in four (7.4%) patients, hyperdynamic left ventricle in one (1.9%) patient, and pulmonary hypertension in one (1.9%) patient. Long QTc interval was noticed in three (5.6%) and cardiomegaly was detected in 18 (33.3%) patients. Conclusion Cardiovascular complications occurred at a high frequency in our pediatric population despite high baseline hemoglobin F levels. Early evaluation and continuous monitoring are important for early intervention.

Prolonged QTc Interval in Nigerian Children with Sickle Cell Anemia

Prolonged QTc interval, a risk factor for ventricular arrhythmia, occurs in sickle cell anemia. The aim of this study was to determine the risk of prolonged QTc interval and its relationship with vaso-occlusive painful crises (VOCs) and follow-up steady-state in the same children with sickle cell anemia. This prospective cohort study enrolled 38 subjects, aged 5-17 years. History of bone pain and examination were obtained during VOC and steady-state. Assessment of QTc interval was with 12-lead electrocardiography. The QTc interval value >0.440 seconds was taken as prolonged. Median (interquartile range) of QTc interval was higher during VOC [0.447 (0.438-0.459) seconds] than during steady-state [0.435 (0.417-0.440) seconds]. Risk of prolonged QTc interval was higher during VOC (68.4%) than in steady-state (21.1%) with relative risk of 3.250 [95% confidence interval (CI) = 1.692-6.241]. Prolonged QTc interval was likely to occur [area under curve (AUC) = 0.759, p<0.001] during VOC with 68.4% sensitivity, 78.9% specificity and at cutoff point of 0.441 seconds. Prolonged QTc interval negatively correlated with packed cell volume (PCV) during VOC [r_s (36) = -0.14, p = 0.387]. Binary logistics of the combined effect of PCV and gender on QTc interval showed that during VOC, males were more likely to have prolonged QTc [odds ratio (OR): 1.337 (95% CI: 0.327-5.464; p = 0.686]. Children with sickle cell anemia, particularly males, were three-times more likely to have prolonged QTc interval during VOC when QTc interval was >0.441 seconds. Routine electrocardiography may help to identify those with QTc intervals above this threshold for prompt cardiac-oriented management.

Relationship Between Disease Severity and Resting Electrocardiograms of Adults With Sickle Cell Anemia in a Tertiary Institution in Southern Nigeria

Introduction

Sickle cell anemia (SCA) in adults has many clinical manifestations. These manifestations are due to effects of recurrent hemolysis, anemia, and ischemia-reperfusion injury on various organs, including the heart. These factors determine the severity of the disease.

Objectives

The aim of the study was to assess the severity of SCA using a scoring system consisting of clinical and laboratory parameters. In addition, the study aimed to determine the electrocardiographic abnormalities in the adult SCA population.

Study design

This was a cross-sectional, observational study conducted in the medical outpatient clinic of Irrua Specialist Teaching Hospital, Irrua, Nigeria.

Methodology

Sixty SCA patients who were older than 18 years old were recruited for this study between February 2017 and January 2018. Sixty healthy individuals matched for age and sex were recruited to serve as controls. Patients who were pregnant or having an acute crises were excluded from the study. Each participant had an electrocardiogram and a SCA severity score was calculated using their clinical history and complete blood count. Data analysis was carried out using the IBM Statistical Package for Social Sciences Statistics® software, version 21 (IBM SPSS Statistics for Windows, Armonk, NY) and statistical significance assigned to p-values less than 0.05.

Results

Severity scores for SCA ranged between 7 and 24, with a mean score of 14.5 ± 4.04. Out of the 60 patients, 14 (23.3%), 39 (65%), and seven (11.7%) participants met criteria for mild, moderate, and severe disease, respectively. Tachycardia, prolonged QTc, and the presence of ST-segment and T-wave abnormalities were significantly associated with severe SCA (p = 0.024, p = 0.027, and p = 0.018, respectively). There was positive correlation between SCA severity scores and P-wave duration (r = 0.327, p = 0.011), QRS dispersion (r = 0.298, p = 0.021), QTc interval (r = 0.332, p = 0.010), and QTc dispersion (r = 0.320, p = 0.013).

Conclusion

This study demonstrated that moderate and severe forms of SCA are common in our region. Tachycardia, left atrial abnormality, prolonged corrected QT interval, and the presence of ST-segment and T-wave changes are electrocardiographic findings associated with more severe forms of the disease. These abnormalities are significant etiologies of cardiac morbidity and mortality in SCA.

IL-18 mediates sickle cell cardiomyopathy and ventricular arrhythmias

Previous reports indicate that IL18 is a novel candidate gene for diastolic dysfunction in sickle cell disease (SCD)-related cardiomyopathy. We hypothesize that interleukin-18 (IL-18) mediates the development of cardiomyopathy and ventricular tachycardia (VT) in SCD. Compared with control mice, a humanized mouse model of SCD exhibited increased cardiac fibrosis, prolonged duration of action potential, higher VT inducibility in vivo, higher cardiac NF-κB phosphorylation, and higher circulating IL-18 levels, as well as reduced voltage-gated potassium channel expression, which translates to reduced transient outward potassium current (Ito) in isolated cardiomyocytes. Administering IL-18 to isolated mouse hearts resulted in VT originating from the right ventricle and further reduced Ito in SCD mouse cardiomyocytes. Sustained IL-18 inhibition via IL-18-binding protein resulted in decreased cardiac fibrosis and NF-κB phosphorylation, improved diastolic function, normalized electrical remodeling, and attenuated IL-18-mediated VT in SCD mice. Patients with SCD and either myocardial fibrosis or increased QTc displayed greater IL18 gene expression in peripheral blood mononuclear cells (PBMCs), and QTc was strongly correlated with plasma IL-18 levels. PBMC-derived IL18 gene expression was increased in patients who did not survive compared with those who did. IL-18 is a mediator of sickle cell cardiomyopathy and VT in mice and a novel therapeutic target in patients at risk for sudden death.

Sickle cell disease-associated arrhythmias and in-hospital outcomes: Insights from the National Inpatient Sample

BACKGROUND

The frequency and temporal trend in the prevalence of arrhythmias and associated in-hospital outcomes in patients with sickle cell disease (SCD) have never been quantified.

METHODS

Our study cohort of SCD patients and sub-types of arrhythmias were derived from the 2010-2014 National Inpatient Sample using relevant diagnostic codes. The frequency and trends of arrhythmia and odds of inpatient mortality were measured.

RESULTS

A total of 891 450 hospitalized SCD patients were identified, of which, 55 616 (6.2%) patients experienced arrhythmias. The SCD cohort with arrhythmia demonstrated higher all-cause mortality (2.7% vs 0.4%; adjusted OR 2.53, 95% CI 2.15-2.97, P < .001), prolonged hospital stays (6.9 vs 5.0 days) and higher hospital charges ($53 871 vs $30 905) relative to those without arrhythmias (P < .001).The frequency of supraventricular arrhythmia (AFib, SVT, and AF) and ventricular arrhythmia (VFib and VT) were 1893 and 362 per 100 000 SCD-related admissions, respectively. Unspecified arrhythmias (4126) were seen most frequently followed by AFib (1622) per 100 000 SCD-related admissions. From 2010 to 2014, the frequency of any arrhythmias and atrial fibrillation in hospitalized SCD patients relatively increased by 29.6% and 38.5%, respectively. There was nearly a twofold (2.4% in 2010 to 5.0% in 2014) increase in the frequency of arrhythmia among patients aged <18 years. The frequency of arrhythmias in hospitalized male and female SCD patients relatively increased by 28.8% and 31.4%, respectively (P trend < .001).

CONCLUSIONS

The frequency of arrhythmias among SCD patients is on the rise with worse hospitalization outcomes, including higher in-hospital mortality and higher resource utilization as compared to those without arrhythmias.

Reversal of a rheologic cardiomyopathy following hematopoietic stem cell transplantation for sickle cell disease

Cardiac complications have been well-described in sickle cell disease; however, it has been rare to see improvements in cardiac abnormalities following any interventions. Previous work has shown no significant structural changes after treatment with hydroxyurea. The cardiac effects of red blood cell exchange transfusion (RBCx) and hematopoietic stem cell transplantation (HSCT) have not been well described. We studied 56 patients undergoing HSCT (41 HLA-matched, 15 haploidentical), of whom 32 had RBCx within 3 months before HSCT. Echocardiograms and laboratory parameters were obtained at baseline, and at 3, 6, and 12 months following HSCT. Although hemolytic parameters and anemia improved following RBCx, there was a small increase in left ventricular volume index. Following successful HSCT, however, there were significant improvements in cardiac size, function, and diastolic filling parameters at 3 months followed by continued smaller improvements up to 1 year. There was a significant improvement in N-terminal pro B-type natriuretic peptide levels and a trend toward improvement in 6-minute walk time 1 year after HSCT. The magnitude of cardiac improvement seen following HSCT was comparable to that observed following correction of a volume overload state as seen in pregnancy or after repair of chronic valvular regurgitation. Further studies in sickle cell disease patients will help delineate which cardiac complications and what level of severity should be considered indications for HSCT.

Impact of relative systemic hypertension on the heart in sickle cell anaemia

Sickle cell anaemia (SCA) is associated with macrovascular complications at relatively normal blood pressures. This has led to the development of the term 'relative systemic hypertension' (RSH). The electrocardiography (ECG) and echocardiography (ECHO) findings in these people has not been well highlighted. Patients with SCA in steady state were consecutively recruited. History, physical examination, ECG and ECHO information were obtained from all participants after informed consent was obtained. Eighty-three people were recruited in all- 15 of which had RSH, giving a prevalence of 18.1%. Those with RSH had higher packed cell volumes (PCV), smaller right atria area, lower tricuspid regurgitant velocities, lower incidence of early satiety, longer QTc and higher frequency of a history of vaso-occlusive crises. The indices of right and left ventricular function were normal in both groups. Right atrial area was the only significant determinant of RSH in this study. RSH is associated with higher PCV, longer QTc and smaller right atrial area in SCA patients. More studies to evaluate sympathetic output in SCA with RSH is required.

Cardiovascular Sequelae of Sickle Cell Disease

Sickle cell disease (SCD) is one of the most common hereditary hemoglobinopathies worldwide. It is a multisystem disease that causes considerable patient morbidity. Despite advances in medical treatment, cardiopulmonary complications remain the most common cause of death in individuals with SCD. A growing body of evidence has shown that SCD results in a spectrum of cardiovascular complications through a variety of mechanisms, including chronic hemolysis, local tissue hypoxia, increased oxidative stress, and autonomic instability. Herein, we will examine the pathophysiology of sickle cell vasculopathy and discuss the spectrum of cardiovascular sequelae of the disease, while highlighting the impact of SCD on the cardiovascular health of the patients.

Hospitalized cancer patients with acquired long QT syndrome-a matched case-control study

Background

Our recent study has revealed that many hospitalized patients with acquired long QT syndrome (ALQTS) are cancer patients. This study aims to determine the risk factors and outcomes of hospitalized cancer patients with ALQTS.

Methods

We performed a matched case-control study within a cohort of 10,180 cancer patients hospitalized between September 2013 and April 2016. Among them, 150 patients defined as having severe ALQTS with a markedly prolonged QT interval (QTc ≥ 500 ms) were compared with 293 age-, sex- and cancer-type-matched controls (non-ALQTS). Death as the endpoint was followed for up to 2 years. Cox regression and Kaplan-Meier survival analyses were performed to assess the effects of particular clinical variables on all-cause mortality. Multivariate logistic regression was performed to calculate odds ratios (OR) for various predictors of QT prolongation.

Results

The mortality was significantly higher in ALQTS group (63.3% vs. 33.4%). Hypertension, hypokalemia, hypocalcemia, QT-prolonging drugs, infection, anemia, anti-microtubule agents were contributing factors to ALQTS. Renal insufficiency, male gender and hypokalemia were found to be independent risk factors for all-cause mortality in ALQTS group.

Conclusion

Markedly prolonged QT interval was seen in 1.5% of hospitalized cancer patients. The all-cause mortality was high in cancer patients with severe ALQTS.

Cardiovascular complications of sickle cell disease

Sickle cell disease (SCD) is the most common inherited blood disorder in the United States, and a global health problem. Pathological features of the abnormal hemoglobin (HbS) result in 2 hallmarks of the disease - recurrent episodes of acute microvascular occlusion and chronic hemolytic anemia - that inflict continuous and insidious damage to multiple organs. With improved childhood survival, SCD in adults has evolved into a chronic degenerative disease with underlying damage to multiple organs including the heart and lungs. Cardiopulmonary complications, including cardiomyopathy, diastolic dysfunction, pulmonary hypertension (PH), and sudden cardiac death are the most common causes of morbidity and mortality. Awareness of the sickle-related cardiovascular phenotypes is important for screening, early diagnosis, and intervention of cardiac complications in this disorder.

Association of sickle cell trait with atrial fibrillation: The REGARDS cohort

BACKGROUND

Sickle cell trait (SCT), sickle cell disease's (SCD) carrier status, has been recently associated with worse cardiovascular and renal outcomes. An increased prevalence of atrial fibrillation (AF) is documented in SCD patients; however, studies in individuals with SCT are lacking.

OBJECTIVES

To determine the association of SCT with AF.

METHODS

Among African-American participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study we assessed the association of SCT (by ECG or medical history) with prevalent AF using logistic regression adjusting for age, sex, income, education, history of stroke, myocardial infarction, diabetes, hypertension, and chronic kidney disease. A second evaluation was performed a mean of 9.2 years later among available participants, and the same model was used to test the association of SCT with incident AF.

RESULTS

In 10,409 participants with baseline ECG data and genotyping, 778 (7.5%) had SCT and 811 (7.8%) had prevalent AF. After adjusting for age, sex, education and income, SCT was associated with AF, OR 1.32 (95% CI 1.03-1.70). The association with incident AF assessed at the second in-home visit with the same adjustments was similar; OR 1.25 (95% CI 0.77-2.03).

CONCLUSIONS

SCT was associated with a higher prevalence of AF and a non-significantly higher incident AF over a 9.2 year period independent of AF risk factors. SCT remained associated with prevalent AF after adjusting for potential factors on the causal pathway such as hypertension and chronic kidney disease suggesting alternate mechanisms for the increased risk.

Management of severe chronic pain with methadone in pediatric patients with sickle cell disease

Vasocclusive pain crises are common among pediatric patients with sickle cell disease (SCD). Some patients with repeated pain crises develop chronic pain. We performed a retrospective cohort study of pediatric patients with SCD with chronic pain treated with methadone. We identified a significant reduction in pain hospitalizations following methadone treatment (0.35 ± 0.19 vs. 0.19 ± 0.17 hospitalizations/month, P = 0.016). In addition, we did not observe overt organ toxicity nor symptoms of opioid withdrawal during methadone wean. We suggest that methadone is safe and has some clinical benefit, which should be proven in prospective randomized trials for pediatric patients with SCD and chronic pain.

Plasma homocysteine levels associated with a corrected QT interval

BACKGROUND

Little is known about the relationship between homocysteine (Hcy) levels and the QT interval. We examined the association of different Hcy levels with corrected QT (QTc) intervals in a general population.

METHODS

Plasma levels of Hcy were assessed in a population-based study of 7002 participants 35 years of age and older from 2012 to 2013. Twelve-lead ECGs were performed on all participants and analyzed automatically.

RESULTS

The distribution of Hcy levels was determined for an entire population after the data were grouped into quartiles (Q1: <=11.1umol/L; Q2: 11.1-13.8umol/L; Q3: 13.8-18.2 umol/L; Q4 > 18.2 umol/L). The mean value of the QTc interval in each quartile was 433.2 ± 23.8 ms, 430.0 ± 24.6 ms, 429.2 ± 24.5 ms and 430.6 ± 25.7 ms. Multiple logistic regression analyses showed that, compared with the second quartile, and after fully adjusting for potential confounding factors, the odds for QTc > 440 ms in the first and fourth quartile increased (P < 0.05), (OR: 1.23, 95% CI: 1.05-1.43 for Q1; OR: 1.40, 95% CI: 1.19-1.65 for Q4).

CONCLUSIONS

QTc interval was associated with the Hcy level in this general population.

Risk factors for mortality in adult patients with sickle cell disease: a meta-analysis of studies in North America and Europe

Although recent studies show an improved survival of children with sickle cell disease in the US and Europe, for adult patients mortality remains high. This study was conducted to evaluate the factors associated with mortality in adult patients following the approval of hydroxyurea. We first evaluated the association between selected variables and mortality at an academic center (University of North Carolina). Data sources were then searched for publications from 1998 to June 2016, with meta-analysis of eligible studies conducted in North America and Europe to evaluate the associations of selected variables with mortality in adult patients. Nine studies, combined with the UNC cohort (total n=3257 patients) met the eligibility criteria. Mortality was significantly associated with age (per 10-year increase in age) [7 studies, 2306 participants; hazard ratio (HR): 1.28; 95% confidence interval (CI): 1.10-1.50], tricuspid regurgitant jet velocity 2.5 m/s or more (5 studies, 1577 participants; HR: 3.03; 95%CI: 2.0-4.60), reticulocyte count (3 studies, 1050 participants; HR: 1.05; 95%CI: 1.01-1.10), log(N-terminal-pro-brain natriuretic peptide) (3 studies, 800 participants; HR: 1.68; 95%CI: 1.48-1.90), and fetal hemoglobin (7 studies, 2477 participants; HR: 0.97; 95%CI: 0.94-1.0). This study identifies variables associated with mortality in adult patients with sickle cell disease in the hydroxyurea era.

Associations of Prolonged QTc in Sickle Cell Disease

Sudden death is a leading cause of mortality in sickle cell disease, implicating ventricular tachyarrhythmias. Prolonged QTc on an electrocardiogram (ECG), commonly seen with myocardial ischemia, is a known risk for polymorphic ventricular tachycardia (VT). We hypothesized that prolonged QTc is associated with mortality in sickle cell disease. ECG were analyzed from a cohort of 224 sickle patients (University of Illinois at Chicago, UIC) along with available laboratory, and echocardiographic findings, and from another cohort of 38 patients (University of Chicago, UC) for which cardiac MRI and free heme values were also measured. In the UIC cohort, QTc was potentially related to mortality with a hazard ratio (HR) of 1.22 per 10ms, (P = 0.015), and a HR = 3.19 (P = 0.045) for a QTc>480ms. In multivariate analyses, QTc remained significantly associated with survival after adjusting for inpatient ECG status (HR 1.26 per 10ms interval, P = 0.010) and genotype status [HR 1.21 per 10ms interval, P = 0.037). QTc trended toward association with mortality after adjusting for both LDH and hydroxyurea use (HR 1.21 per 10ms interval, P = 0.062) but was not significant after adjusting for TRV. In univariate analyses, QTc was related to markers of hemolysis including AST (P = 0.031), hemoglobin (P = 0.014), TR velocity (P = 0.036), higher in inpatients (P<0.001) and those with an SS compared to SC genotype (P<0.001) in the UIC cohort as well as to free heme in the UC cohort (P = 0.002). These findings support a relationship of prolonged QTc with hemolysis and potentially mortality in sickle cell disease.

Cardiovascular complications and risk of death in sickle-cell disease

In sickle-cell disease, a point mutation in the β-globin chain causes haemoglobin to polymerise within erythrocytes during deoxygenation, altering red blood cell rheology and causing haemolysis. Improvements in health infrastructure, preventive care, and clinical treatments have reduced the morbidity and mortality of sickle-cell disease in developed countries. However, as these patients live longer, the chronic effects of sustained haemolytic anaemia and episodic vaso-occlusive events drive the development of end-organ complications. Cardiopulmonary organ dysfunction and chronic kidney injury have a large effect on morbidity and premature mortality, and typically accelerate in the second decade of life. These processes culminate in the development of pulmonary hypertension, left ventricular diastolic heart disease, dysrhythmia, and sudden death. In this Series paper, we review the mechanisms, clinical features, and epidemiology of major cardiovascular complications in patients with sickle-cell disease and discuss how screening and intervention could reduce their incidence.

QT interval variations and mortality risk: is there any relationship?

Abnormal prolongation and shortening of the electrocardiographic QT interval duration, which occur in the hereditary forms of long and short QT syndromes, are associated with an increased risk of ventricular arrhythmias and sudden cardiac death. Even within the normal range, these altered durations are associated with an increased mortality risk in the general population. While extreme prolongation or reduction of the QT interval predisposes patients to malignant ventricular arrhythmias and sudden cardiac death, the precise dose-response relationship between the QT interval and cardiovascular disease mortality is still unknown. This paper describes the need for more standardized methods for measuring and reporting the QT interval and the need for more precise assessments of the risk associated with QT interval variation.

Mechanisms linking red blood cell disorders and cardiovascular diseases

The present paper aims to review the main pathophysiological links between red blood cell disorders and cardiovascular diseases, provides a brief description of the latest studies in this area, and considers implications for clinical practice and therapy. Anemia is associated with a special risk in proatherosclerotic conditions and heart disease and became a new therapeutic target. Guidelines must be updated for the management of patients with red blood cell disorders and cardiovascular diseases, and targets for hemoglobin level should be established. Risk scores in several cardiovascular diseases should include red blood cell count and RDW. Complete blood count and hemorheological parameters represent useful, inexpensive, widely available tools for the management and prognosis of patients with coronary heart disease, heart failure, hypertension, arrhythmias, and stroke. Hypoxia and iron accumulation cause the most important cardiovascular effects of sickle cell disease and thalassemia. Patients with congenital chronic hemolytic anemia undergoing splenectomy should be monitored, considering thromboembolic and cardiovascular risk.