Myocardial ischaemia in sickle cell anaemia: evaluation using a new scoring system

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.

Aerobic physical capacity and health-related quality of life in children with sickle cell disease

BACKGROUND

Aerobic fitness is a predictor of cardiovascular health which correlates with health-related quality of life in the general population. The aim is to evaluate the aerobic capacity by cardiopulmonary exercise test (CPET) in children with sickle cell disease in comparison with healthy matched controls.

METHODS

Controlled cross-sectional study.

RESULTS

A total of 72 children (24 with sickle cell disease and 48 healthy controls), aged 6-17 years old were enrolled. Children with sickle cell disease had a poor aerobic capacity, with median VO2max Z-score values significantly lower than matched controls (-3.55[-4.68; -2.02] vs. 0.25[-0.22; 0.66], P < 0.01, respectively), and a high proportion of 92% children affected by an impaired aerobic capacity (VO2max Z-score < -1.64). The VO2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease and health-related quality of life.

CONCLUSION

Aerobic capacity is poor in children with sickle cell disease. VO2max decrease is associated with the level of anemia, the existence of a homozygote HbS/S mutation, lung function, and health-related quality of life. These results represent a signal in favor of early initiation of cardiac rehabilitation in patients with sickle cell disease.

CLINICAL TRIALS

NCT05995743.

IMPACT

Aerobic fitness is a predictor of cardiovascular health which correlates with health-related quality of life in the general population. Aerobic capacity (VO2max) is poor in children with sickle cell disease, despite the absence of any pattern of heart failure. VO2max decrease was associated with the level of anemia, the existence of a homozygote HbS/S mutation, restrictive lung disease, and health-related quality of life. These results are in favor of early initiation of cardiac rehabilitation in children with sickle cell disease.

Blood pressure and electrocardiographic profile of children with sickle cell anaemia in steady-state and vaso-occlusive crisis

Objective

To compare the cardiovascular features of patients with sickle cell anaemia (SCA) in steady-state with those in vaso-occlusive crisis (VOC) at the Wesley Guild Hospital (WGH).

Design

A descriptive cross-sectional, matched, case-control study among children with SCA at the WGH, a tertiary health facility in southwest Nigeria.

Setting

The participants were recruited from the children's emergency unit and paediatric haematology clinic of the WGH.

Participants

Consisted of 93 children with VOC (cases) and 93 age and sex-matched in steady state (controls), aged 5 - 15 years.

Main outcome measures

Cardiovascular parameters, including pulse rate, blood pressure, and electrocardiographic profile, were assessed and compared using the appropriate statistical tests.

Results

The mean (SD) age of the cases and controls were 8.8 (3.2) years and 9.0 (3.1) years, respectively (p= 0.106). There was no significant difference in the mean height of the groups. The mean pulse rate, diastolic, systolic, and mean arterial pressures were significantly higher in the cases than in the controls. A significantly higher proportion of the cases than the controls also had a higher frequency of heart blocks, prolonged QTc interval, ST elevation or depression, and T wave abnormality (p = 0.018, 0.039, 0.041, 0.009, respectively). The prevalence of chamber enlargements was not significantly different between the two groups.

Conclusion

Cardiovascular dysfunction is worse during VOC when compared with steady state. Physicians should look for these dysfunctions in SCA children with VOC to reduce mortality from the disease.

Funding

None declared.

Sickle cell disease as an accelerated aging syndrome

Sickle cell disease (SCD) is characterized by vaso-occlusion, hemolysis, and systemic manifestations that form the hallmark of the disease. Apart from morbidity, SCD is also associated with increased mortality and decreased quality of life. Aging is a natural phenomenon that is associated with changes at cellular, tissue, and organ levels, in addition to the loss of physical fitness, increased susceptibility to diseases, and a higher likelihood of mortality. Some of the cellular mechanisms involved in normal (or physiological) aging include abnormalities of sphingolipids (ceramides) and reduced length of the telomere. These changes have also been documented in SCD. Cellular, organs, and physical manifestations of SCD resemble an accelerated aging syndrome. Sickle erythrocytes also acquire morphological features similar to that of aged normal erythrocytes and are thus picked up early by the macrophages for destruction. Brain, kidney, heart, innate and adaptive immune system, and musculoskeletal system of patients with SCD exhibit morphological and functional changes that are ordinarily seen in the elderly in the general population. Stroke, silent cerebral infarcts, cardiomegaly, heart failure, pulmonary hypertension, nephropathy with proteinuria, osteopenia, osteoporosis, osteonecrosis, gout, and infections are exceedingly common in SCD. In this review, we have attempted to draw parallels between SCD and accelerated aging syndromes.

Clinical Utilities of Electrocardiography in the Diagnosis of Myocardial Ischemia in Children With Sickle Cell Anemia: Correlation With Serum Cardiac Troponin I

BACKGROUND

Sickle cell anemia (SCA) is associated with recurrent vaso-occlusive crisis (VOC) and the risk of myocardial ischemia (MI). This study investigated the utility of electrocardiography (ECG) and cardiac troponin I (cTnI) in diagnosing MI during VOC.

MATERIALS AND METHODS

Children with SCA 5 to 15 years of age in VOC (patients) and age-matched and sex-matched steady-state controls were studied. Their ECG and cTnI levels were measured at contact and after 4 to 6 weeks.

RESULTS

One hundred eighty-six children (93 patients and 93 controls) were studied. The mean (SD) ages of the patients and controls were 8.8 (3.2) and 9.0 (3.1) years, respectively. The mean MI score was significantly higher for the patients, 1.7 (1.2), than the controls, 1.3 (1.0), P=0.002. A significantly higher proportion of the patients, 18 (19.4%), also had significant ischemia compared with the controls, 8 (8.6%), P=0.016. The median (interquartile range) serum cTnI level was significantly higher in the patients than the controls, P=0.006. All 7 of the patients with elevated cTnI had VOC. No significant correlation was found between MI score and cTnI in both groups.

CONCLUSIONS

cTnI is elevated and ECG features of MI worsen during VOC. Longitudinal studies to investigate their evolvement over time are advocated.

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.

Myocardial injury in patients with sickle cell anaemia and myocardial ischaemia in Calabar, Nigeria

Background In children with sickle cell anaemia (SCA), ischaemic electrocardiogram (ECG) changes occur during both vaso-occlusive crises (VOC) and the steady state. Myocardial ischaemia evidenced by an ischaemic pattern on ECG may lead to myocardial injury which is evidenced by elevated serum cardiac troponin T (cTnT). Occasionally, the myocardial injury is fatal. Aim To determine the relationship between raised serum cTnT levels and an ischaemic ECG pattern in children with SCA. Methods This was a dual study design comprising a prospective cohort study of a group of children with SCA observed during VOC and 6 weeks later during follow-up steady state, and a case-control study of SCA children and apparently healthy children. The subjects were 34 SCA children aged 5-17 years and 34 age- and sex-matched apparently healthy controls with haemoglobin genotype AA attending University of Calabar Teaching Hospital. VOC was diagnosed by clinical examination and a history of bone pain. During VOC and follow-up steady state, an ECG was performed and blood taken for serum cTnT estimation. In the apparently healthy children, only serum cTnT was estimated. Serum cTnT was analysed by electrochemiluminescence immune-assay. Ischaemic ECG was assessed using the World Heart Federation criteria. Results Twenty-eight (82.4%) SCA children had elevated serum cTnT during VOC and it was elevated in only six (17.6%) of them during the steady state. An ischaemic ECG was observed in 25 (73.5%) and 20 (58.8%) of them during VOC and the steady state, respectively. Ischaemic ECG identified SCA children with elevated cTnT during VOC (sensitivity 75%, specificity 33.3%) and the follow-up steady state (sensitivity 50%, specificity 39.3%). Measures of agreement between ECG and cTnT in detecting myocardial injury were poor during VOC (κ 0.07, p = 0.68) and the follow-up steady state (κ - 0.06, p = 0.63). Conclusions Most SCA children have an ischaemic ECG with elevated serum cTnT, especially during VOC, which suggests ischaemic-induced cardiac injury. However, elevated serum cTnT can occur without an ischaemic ECG and vice versa. Performing only electrocardiography or cTnT to detect ischaemia-induced cardiac injury may be misleading. Therefore, when there is a high index of suspicion, both tests should be undertaken, especially during VOC, to ensure prompt, effective treatment. Abbreviations AHC, apparently healthy children; AUC, area under the ROC curve; BMI, body mass index; cTnT, cardiac troponin T; ECG, electrocardiogram; EDTA, ethylene diamine tetra-acetic acid; GFR, glomerular filtration rate; HbS, haemoglobin S; HLA, human leucocyte antigen; LVH, left ventricular hypertrophy; ROC, receiver operating characteristic; SCA, sickle cell anaemia; UCTH, University of Calabar Teaching Hospital; URL, upper reference limit; USFDA, United States Food and Drug Administration; USNIH, United States National Institutes of Health; VOC, vaso-occlusive painful crisis; WHF, World Heart Federation.

Cardiovascular changes in children with sickle cell crisis

BACKGROUND

Sickle cell anaemia is characterised by frequent, sometimes serious events referred to as "crisis". Cardiopulmonary consequences such as pulmonary hypertension and myocardial ischaemia may accompany a serious crisis.

OBJECTIVE

To determine the cardiovascular changes that occur during a severe sickle cell crisis.

METHODS

A cross-sectional comparative study of sickle cell anaemia in children (5-17 years) admitted during a severe crisis (cases) and those in steady state (controls) was conducted over a 2-year period. Effects of the crisis on the cardiopulmonary system were assessed. The diagnosis of myocardial ischaemia was made using electrocardiography and serological cardiac biomarkers, while cardiac dysfunction and the presence of pulmonary hypertension were determined using echocardiography. The presence of systemic hypertension and tachycardia was also evaluated.

RESULTS

A total of 176 patients were recruited, 92 in steady state (male:female ratio, 1.2:1) and 84 in severe crisis (male:female ratio, 1.3:1). The mean age was 10.4 ± 3.2 years for steady state and 10.5 ± 3.4 years for those in crisis. The mean heart rate in crisis was higher than in steady state (p < 0.0001). The blood pressures (systolic, p < 0.0001, diastolic, p < 0.0001, mean, p < 0.0001) as well as myocardial ischaemia scores (p < 0.0001) were higher in patients with crisis than in those in steady state. Similarly, conduction abnormalities, pulmonary hypertension, and ventricular dysfunction were more prevalent in the crisis than in the steady state.

CONCLUSION

The present data suggest that sickle cell crisis results in a derangement of clinical, electrocardiographical, and echocardiographical parameters in children with sickle cell anaemia. Further research on these cardiovascular events may improve the overall care of these patients.

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.

Care of the Critically Ill Pediatric Sickle Cell Patient

Sickle cell disease is the most common inherited disease in the United States. Through the effects of hemolysis and vaso-occlusion, it has the potential to incite critical illness involving multiple organ systems. Children with sickle cell disease are at risk of multiple types of shock resulting in a need for ICU care. Our youngest patients with sickle cell disease are at highest risk of infection due to lack of splenic function, and this can present with septic shock. Hypovolemic shock can occur secondary to severe acute anemia as seen with splenic sequestration or a delayed transfusion reaction. As one ages, the risk of cardiac dysfunction – diastolic and systolic dysfunction as well as pulmonary hypertension – can result in cardiogenic shock. In addition to shock, patients with sickle cell disease are at risk for respiratory failure from acute chest syndrome as well as acute neurologic deterioration from stroke. For these reasons, critical care physicians must be familiar with the unique management of sickle cell complications in order to provide the best possible care for this vulnerable population.

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.

Electrocardiographic abnormalities and dyslipidaemic syndrome in children with sickle cell anaemia

Background

Lipid and electrocardiographic (ECG) abnormalities have been reported in adults with sickle cell anaemia (SCA) and may reflect underlying structural and/ or functional damage. However, the relationship between ECG and lipid abnormalities among children with sickle cell disease is not fully understood.

Objectives

To compare the steady-state lipid and ECG abnormalities in children with SCA to the controls and examine the hypothesis that lipid abnormalities are closely related to electrocardiographic abnormalities, and therefore are a reflection of cardiac damage among these children.

Methods:

Clinical, laboratory and ECG profiles of 62 children with SCA and 40 age- and gender-matched haemoglobin AA controls were compared. The influence of clinical characteristics, lipids profiles, markers of haemolysis, and renal and hepatic dysfunction on ECG pattern in children with SCA was then determined.

Results

The patients had lower average diastolic and mean arterial blood pressure, total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels than the controls, (p = 0.001, 0.002, 0.000 and 0.000, respectively). The mean triglyceride level was significantly higher (p < 0.001), while high-density lipoprotein cholesterol (HDL-C) levels were comparable (p = 0.858). The cases were about six times more likely to have left ventricular hypertrophy than the controls (OR = 6.4, 95% CI = 2.7–15.6, p = 0.000). Haematocrit level had a negative correlation with QT_C (r = –0.3, p = 0.016) and QT intervals (r = – 0.3, p = 0.044). Triglyceride levels had a positive correlation with the PR interval (r = 0.3, p = 0.012), while serum alanine transferase (ALT) concentrations had an inverse correlation with PR interval (r = –0.3, p = 0.015). There was no statistical difference in the sociodemographic and clinical characteristics of the SCA children with or without ECG abnormalities. However, the mean triglyceride and serum ALT levels in those with ECG abnormalities were significantly higher than those without (p = 0.007 and 0.045, respectively).

Conclusion

Lipid and ECG abnormalities are common in children with SCA. Elevated triglyceride and serum ALT levels are possible biochemical markers of ECG abnormalities in these patients.

Cardiovascular abnormalities in sickle cell disease

Sickle cell disease is characterized by recurrent episodes of ischemia-reperfusion injury to multiple vital organ systems and a chronic hemolytic anemia, both contributing to progressive organ dysfunction. The introduction of treatments that induce protective fetal hemoglobin and reduce infectious complications has greatly prolonged survival. However, with increased longevity, cardiovascular complications are increasingly evident, with the notable development of a progressive proliferative systemic vasculopathy, pulmonary hypertension (PH), and left ventricular diastolic dysfunction. Pulmonary hypertension is reported in autopsy studies, and numerous clinical studies have shown that increased pulmonary pressures are an important risk marker for mortality in these patients. In epidemiological studies, the development of PH is associated with intravascular hemolysis, cutaneous leg ulceration, renal insufficiency, iron overload, and liver dysfunction. Chronic anemia in sickle cell disease results in cardiac chamber dilation and a compensatory increase in left ventricular mass. This is often accompanied by left ventricular diastolic dysfunction that has also been a strong independent predictor of mortality in patients with sickle cell disease. Both PH and diastolic dysfunction are associated with marked abnormalities in exercise capacity in these patients. Sudden death is an increasingly recognized problem, and further cardiac investigations are necessary to recognize and treat high-risk patients.