Biomedical subjects
Publications and source records attributed to Steven E Lipshultz.
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BACKGROUND: Animal data show that low protein intake in pregnancy programs higher offspring blood pressure, but similar data in humans are limited. We examined the associations of first and second trimester maternal protein intake with offspring blood pressure (BP) at the age of six months. METHODS: In a prospective US cohort study, called Project Viva, pregnant women completed validated semi-quantitative food-frequency questionnaires (FFQ) to measure gestational protein intake. Among 947 mother-offspring pairs with first trimester dietary data and 910 pairs with second trimester data, we measured systolic blood pressure (SBP) up to five times with an automated device in the offspring at the age of six months. Controlling for blood pressure measurement conditions, maternal and infant characteristics, we examined the effect of energy-adjusted maternal protein intake on infant SBP using multivariable mixed effects models. RESULTS: Mean daily second trimester maternal protein intake was 17.6% of energy (mean 2111 kcal/day). First trimester nutrient intakes were similar. Mean SBP at age 6 months was 90.0 mm Hg (SD 12.9). Consistent with prior reports, adjusted SBP was 1.94 mm Hg lower [95% confidence interval (CI) -3.45 to -0.42] for each kg increase in birth weight. However, we did not find an association between maternal protein intake and infant SBP. After adjusting for covariates, the effect estimates were 0.14 mm Hg (95% CI 20.12 to 20.40) for a 1% increase in energy from protein during the second trimester, and 20.01 mm Hg (95% CI 20.24 to -0.23) for a 1% increase in energy from protein in the first trimester. CONCLUSIONS: Variation in maternal total protein intake during pregnancy does not appear to program offspring blood pressure.
BACKGROUND: Few data exist on the intergenerational influence of calcium intake during pregnancy on offspring blood pressure. METHODS AND RESULTS: As part of the ongoing US prospective cohort study Project Viva, we analyzed 4091 Dinamap blood pressure measurements from 936 six-month-old infants whose mothers had completed food frequency questionnaires during the second trimester of pregnancy. We used mixed models to estimate effects of maternal calcium intake on offspring systolic blood pressure. Mean+/-SD daily total maternal calcium intake was 1494+/-523 mg, consisting of 1230+/-486 mg from foods and 264+/-191 mg from supplements. Mean+/-SD 6-month blood pressure was 89.9+/-12.9 mm Hg. From bottom to top quartile of dietary calcium from foods adjusted for energy intake and measurement conditions, mean infant systolic blood pressures were 91.0, 90.2, 90.9, and 90.2 mm Hg (trend P=0.62). From calcium supplements only, the values were 91.5, 90.2, 90.4, and 88.4 mm Hg (trend P=0.006). After further adjustment for demographic, anthropometric, dietary, social, and economic variables, the decrease in 6-month systolic blood pressure was -3.0 mm Hg (95% CI, -4.9 to -1.1) for each 500-mg increment of maternal supplemental calcium intake during pregnancy. We did not find evidence of effect modification by maternal vitamin D or potassium intake or by infant body mass index. First-trimester calcium intake was not associated with offspring blood pressure. CONCLUSIONS: These observational data suggest that supplementing maternal midgestational calcium intake may lower offspring blood pressure, thus helping to prevent hypertension in the next generation.
PURPOSE: Cardiovascular status was assessed in 48 Hodgkin's disease (HD) survivors at a median of 14.3 years (range, 5.9 to 27.5 years) after diagnosis because they may be at increased risk for cardiovascular abnormalities. PATIENTS AND METHODS: Patients completed the Short-Form 36 quality-of-life instrument and were screened by echocardiography, exercise stress testing, and resting and 24-hour ECG. RESULTS: All patients received mediastinal irradiation (median, 40.0 Gy; range, 27.0 to 51.7 Gy) at a median age of 16.5 years (range, 6.4 to 25.0 years). Four patients received an anthracycline. Although every patient described their health as good or better, and none had symptomatic heart disease at screening, all but one had cardiac abnormalities on screening. Restrictive cardiomyopathy was suggested by reduced average left ventricular (LV) dimension (P < .001) and mass (P < .001), without increased LV wall thickness. Significant valvular defects were present in 42%; 75% had conduction defects. One survivor developed complete heart block shortly after the study visit. Autonomic dysfunction was suggested by a monotonous heart rate in 57%, persistent tachycardia in 31%, and blunted hemodynamic responses to exercise in 27%. Peak oxygen uptake (VO2max) during exercise, a predictor of mortality in heart failure, was significantly reduced (< 20 mL/kg/m2) in 30% of survivors. VO2max was correlated with increasing fatigue, increasing shortness of breath (both, r = -0.35; P =. 02), and decreasing physical component score on the SF-36 (r = 0.554; P = .00017). CONCLUSION: A variety of unsuspected, clinically significant cardiovascular abnormalities are common in long-term survivors of HD who are treated at a young age with mediastinal irradiation. We recommend serial, comprehensive cardiac screening of HD survivors who fit this profile.
OBJECTIVES: We studied the outcomes of pediatric patients diagnosed with dilated cardiomyopathy (DCM) and their relation to epidemiologic and echocardiographic variables at the time of presentation. BACKGROUND: The outcome of pediatric DCM patients ranges from recovery to a 50% to 60% chance of death within five years of diagnosis. The impact of heart transplantation and other emerging therapies on the outcomes of pediatric DCM patients is uncertain. METHODS: We performed a retrospective study of the outcomes in 91 pediatric patients diagnosed with DCM from 1990 to 1999. Routine therapy included use of digoxin, diuretics, angiotensin-converting enzyme inhibitors, and heart transplantation. RESULTS: At the time of last follow-up, 11 patients (12%) had died without transplantation; 20 (22%) underwent transplantation; 27 (30%) had persistent cardiomyopathy; and 33 (36%) had recovery of left ventricular systolic function. Overall actuarial one-year survival was 90%, and five-year survival was 83%. However, actuarial freedom from "heart death" (death or transplantation) was only 70% at one year and 58% at five years. Multivariate analysis found age <1 year (hazard ratio 7.1), age >12 years (hazard ratio 4.5), and female gender (hazard ratio 3.0) to be significantly associated with a greater risk of death or transplantation and a higher left ventricular shortening fraction at presentation (hazard ratio 0.92), with a slightly decreased risk of death or transplantation. CONCLUSIONS: Pediatric DCM patients continue to have multiple outcomes, with recovery of left ventricular systolic function occurring most frequently. Utilization of heart transplantation has led to improved survival after the diagnosis of pediatric DCM.
BACKGROUND: Doxorubicin chemotherapy is very effective in children with acute lymphoblastic leukemia (ALL) but also injures myocardial cells. Dexrazoxane, a free-radical scavenger, may protect the heart from doxorubicin-associated damage. METHODS: To determine whether dexrazoxane decreases doxorubicin-associated injury of cardiomyocytes, we randomly assigned 101 children with ALL to receive doxorubicin alone (30 mg per square meter of body-surface area every three weeks for 10 doses) and 105 to receive dexrazoxane (300 mg per square meter) followed immediately by doxorubicin. Serial measurements of serum cardiac troponin T were obtained in 76 of 101 patients in the doxorubicin group and 82 of 105 patients in the group given dexrazoxane and doxorubicin. A total of 2377 serum samples (mean, 15.1 samples per patient) were obtained before, during, and after treatment with doxorubicin. Troponin T levels were evaluated in a blinded fashion to determine whether they were elevated (>0.01 ng per milliliter)--the primary end point--or extremely elevated (>0.025 ng per milliliter). RESULTS: Elevations of troponin T occurred in 35 percent of the patients (55 of 158). Patients treated with doxorubicin alone were more likely than those who received dexrazoxane and doxorubicin to have elevated troponin T levels (50 percent vs. 21 percent, P<0.001) and extremely elevated troponin T levels (32 percent vs. 10 percent, P<0.001). The median follow-up was 2.7 years. The rate of event-free survival at 2.5 years was 83 percent in both groups (P=0.87 by the log-rank test). CONCLUSIONS: Dexrazoxane prevents or reduces cardiac injury, as reflected by elevations in troponin T, that is associated with the use of doxorubicin for childhood ALL without compromising the antileukemic efficacy of doxorubicin. Longer follow-up will be necessary to determine the influence of dexrazoxane on echocardiographic findings at four years and on event-free survival.
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OBJECTIVE: To investigate perinatal predictors of newborn blood pressure. STUDY DESIGN: Among 1059 mothers and their newborn infants participating in Project Viva, a US cohort study of pregnant women and their offspring, we obtained five systolic blood pressure readings on a single occasion in the first few days of life. Using multivariate linear regression models, we examined the extent to which maternal age and other pre- and perinatal factors predicted newborn blood pressure level. RESULTS: Mean (SD) maternal age was 32.0 (5.2) years, and mean (SD) newborn systolic blood pressure was 72.6 (9.0) mm Hg. A multivariate model showed that for each 5-year increase in maternal age, newborn systolic blood pressure was 0.8 mm Hg higher (95% CI, 0.2, 1.4). In addition to maternal age, independent predictors of newborn blood pressure included maternal third trimester blood pressure (0.9 mm Hg [95% CI, 0.2, 1.6] for each increment in maternal blood pressure); infant age at which we measured blood pressure (2.4 mm Hg [95% CI 1.7, 3.0] for each additional day of life); and birth weight (2.9 mm Hg [95% CI, 1.6, 4.2] per kg). CONCLUSIONS: Higher maternal age, maternal blood pressure, and birth weight were associated with higher newborn systolic blood pressure. Whereas blood pressure later in childhood predicts adult hypertension and its consequences, newborn blood pressure may represent different phenomena, such as pre- and perinatal influences on cardiac structure and function.
OBJECTIVE: We explored the association between neuroblastoma and congenital cardiovascular malformations (CCM), previously described in case reports. STUDY DESIGN: Echocardiogram and chart reviews of a series of 158 patients with neuroblastoma and a control group of 192 children with leukemia were performed. The proportion of patients with CCM in each group was compared. RESULTS: Fourteen of the 70 (20%) patients with neuroblastoma and echocardiography had CCM, compared with 7 of the 192 (3.6%) patients with leukemia with echocardiograms (P=.0001). If all of the patients with neuroblastoma without echocardiograms (n=88) are considered to have normal cardiac anatomy, this difference remains significant (14 of 158 patients with neuroblastoma have CCM detected [8.9%] versus 7 of 192 patients with leukemia [3.6%]; P=.045). Neural crest-derived CCM were more common in patients with neuroblastoma, detected in 5 of 70 patients with neuroblastoma versus 2 of 192 patients with leukemia (P=.016). Congenital cardiovascular malformations in patients with neuroblastoma were associated with a cancer diagnosis at age less than 1 year and a lower neuroblastoma stage, but there was no association with tumor MYCN amplification. CONCLUSIONS: Neuroblastoma and CCM may be associated. We recommend echocardiography for CCM screening in patients with newly diagnosed neuroblastoma.
Seroreverters (uninfected children of HIV-infected mothers) have exhibited left ventricular (LV) dysfunction. Mitochondrial toxicity associated with in utero or postnatal exposure to highly active antiretroviral therapy (HAART) is a possible mechanism. Adult and animal models have demonstrated associations between LV abnormalities, cardiomyopathy, and components of HAART. Yet, outcomes in children are poorly understood. In this study, we explore HAART-associated LV abnormalities in seroreverters exposed to HAART (n = 144) or never exposed (n = 252). Subjects are drawn from the Women and Infants Transmission Study and the Pediatric Pulmonary and Cardiovascular Complications of HIV Study, respectively. Data include (1) echocardiographic studies of LV structure and function and (2) serologic cardiac biomarkers (cardiac troponin, probrain natriuretic peptide, high-sensitivity C reactive protein), both collected during the first month of life, and again at 6, 12, 24, 36, and 48 months postnatally. Planned analyses include several regression models. At this time, we have access to data for all 252 unexposed children, and 53 exposed subjects are enrolled. The cohorts are similar in terms of gender and race and the recruited subjects are representative of all eligible subjects in terms of exposure to HAART. Recruitment will continue into 2006.
Over the past decade, the course of human immunodeficiency virus (HIV) infection has been markedly altered by highly active antiretroviral therapy (HAART). As advances in early diagnosis and aggressive therapy, as well as better supportive care, become available to more HIV-infected patients, survival is being prolonged and more patients are experiencing cardiac abnormalities. Cardiovascular manifestations of pediatric HIV infection have especially proven to be an ongoing challenge to practicing physicians, who face cardiac abnormalities ranging from asymptomatic cardiomyopathy to severe heart failure. Antiretroviral therapy has substantially decreased vertical transmission of HIV; however, studies of adults receiving HAART have found increased peripheral and coronary artery disease. Children exposed to this therapy in utero are thus at an increased risk for toxicity and cardiac abnormalities, regardless of their HIV status. Preliminary studies have reported complications including lactic acidosis and mitochondrial toxicity, as well as cardiomyopathy. Further studies are needed to explore the long-term effects and possible toxicities of prophylactic antiretroviral therapy on infants born to HIV-infected mothers.
HIV infection is a global public health issue that is frequently associated with cardiovascular involvement. These HIV-associated cardiovascular manifestations are often clinically occult or attributed incorrectly to other non-cardiac disease processes. A heightened awareness and routine screening for cardiovascular involvement in HIV-infected patients leads to earlier detection and the hope for a reduction in associated morbidity and mortality. Left ventricular dysfunction, an independent predictor of mortality in HIV-infected patients, is the result of many causes in this population and may result in dilated cardiomyopathy and congestive heart failure in about 10% of patients. Other HIV-associated cardiovascular problems include infective endocarditis, cardiovascular malignancy, pulmonary arterial hypertension, vasculitis, pericardial effusion, premature atherosclerosis, and arrhythmias. HIV-associated cardiovascular emergencies include congestive heart failure, pulmonary edema, supraventricular and ventricular arrhythmias, endocarditis, and tamponade. Anti-infective and immunomodulatory therapies may be particularly helpful in this population to reduce associated cardiovascular disease. Highly active antiretroviral therapy may result in lipodystrophy, hyperlipidemia, truncal adiposity, and insulin resistance that can be improved by physical activity and training programs. Cardiovascular complications of therapeutic drugs in HIV-infected patients include torsade de pointes, congestive heart failure, dyslipidemia, accelerated atherosclerosis, and myocardial infarction. In summary, cardiovascular complications are important contributors to morbidity and mortality in HIV-infected patients that can be detected early in many cases and treated effectively.
Exposures to drugs, chemical and biological agents, therapeutic radiation, and other factors before and after birth can lead to pediatric or adult cardiovascular anomalies. Furthermore, nutritional deficiencies in the perinatal period can cause cardiovascular anomalies. These anomalies may affect heart structure, the conduction system, the myocardium, blood pressure, or cholesterol metabolism. Developmental periods before and after birth are associated with different types of risks. The embryonic period is the critical window of vulnerability for congenital malformations. The fetal period seems to have lifelong effects on coronary heart disease and its precursors. During the weeks immediately after birth, susceptibility to myocardial damage seems to be high. Exposure to cancer chemotherapy or radiotherapy in childhood raises the risk of long-term progressive left ventricular dysfunction and other cardiovascular problems. In childhood and adolescence, use of recreational drugs such as cocaine and tobacco poses cardiovascular dangers as well. Where evidence about environmental exposures is limited, we have included models of disease and other exposures that are suggestive of the potential impact of environmental exposures.
OBJECTIVES: The aim of this study was to determine the prevalence of cardiovascular dysfunction and its predictors in children with acquired immunodeficiency syndrome (AIDS). BACKGROUND: Cardiovascular manifestations are common among children with AIDS but may be clinically occult. METHODS: We reviewed the medical records, echocardiograms, electrocardiograms, and Holter monitor studies of 68 children with AIDS. We tested clinical and demographic characteristics at the time of AIDS diagnosis for their ability to predict serious cardiac events, death, and cardiac death. RESULTS: The median time from AIDS diagnosis to death or end of follow-up was 1.0 year (range, 1 week to 7.9 years). Nineteen patients (28%) experienced serious cardiac events after AIDS diagnosis. Of 43 patients who died, 15 (35%) had cardiac dysfunction. Multivariable analyses revealed that recurrent bacterial infections, wasting, encephalopathy, male gender, and an earlier year of AIDS diagnosis were predictors of serious cardiac events (relative risk [RR] = 9.3, 6.9, 4.7, 4.1, and 0.76, respectively, p < 0.05). Wasting, encephalopathy, a low age-adjusted CD4 count, a low age-adjusted immunoglobulin G (IgG) level, and an earlier year of AIDS diagnosis increased the risk of all-cause mortality (RR = 8.9, 5.1, 2.7, 0.82, and 0.8, respectively, p <or= 0.02). Male gender, a low age-adjusted CD4 count, and a low age-adjusted IgG level increased the risk for cardiac death (RR = 16.9, 4.2, and 0.68, respectively, p <or= 0.05). CONCLUSIONS: Serious cardiac events and cardiac death are common among children with AIDS. Factors such as recurrent bacterial infections, wasting, encephalopathy, male gender, low CD4 and IgG levels, and an earlier year at AIDS diagnosis may identify high-risk patients.
BACKGROUND: Population-based data on the incidence of pediatric cardiomyopathy are rare because of the lack of large, prospective studies. METHODS: Since 1996 the Pediatric Cardiomyopathy Registry sponsored by the National Heart, Lung, and Blood Institute has collected data on all children with newly diagnosed cardiomyopathy in New England and the Central Southwest region (Texas, Oklahoma, and Arkansas) of the United States. We report on all children in these regions who received this diagnosis between 1996 and 1999. RESULTS: We identified 467 cases of cardiomyopathy, for an overall annual incidence of 1.13 per 100,000 children (95 percent confidence interval, 1.03 to 1.23). The incidence was significantly higher among infants younger than 1 year old than among children and adolescents who were 1 to 18 years old (8.34 vs. 0.70 per 100,000, P<0.001). The annual incidence of cardiomyopathy was lower among white children (upper-bound estimate, 1.06 cases per 100,000) than among black children (lower-bound estimate, 1.47 per 100,000; P=0.02) and higher among boys than among girls (1.32 vs. 0.92 per 100,000, P<0.001). The incidence also varied significantly by region: 1.44 cases per 100,000 in New England and 0.98 per 100,000 in the Central Southwest region (P<0.001). When categorized according to type, dilated cardiomyopathy made up 51 percent of the cases, hypertrophic cardiomyopathy 42 percent, and restrictive or other types 3 percent; 4 percent were unspecified. There was no significant difference in the incidence rates according to the year. CONCLUSIONS: The estimated incidence of pediatric cardiomyopathy in two large regions of the United States is 1.13 cases per 100,000 children. Most cases are identified at an early age, and the incidence varies according to sex, region, and racial or ethnic origin.
As the number of cancer survivors grows because of advances in therapy, it has become more important to understand the long-term complications of these treatments. This article presents the current knowledge of adverse cardiovascular effects of radiotherapy to the chest. Emphasis is on clinical presentations, recommendations for follow-up, and treatment of patients previously exposed to irradiation. Medline literature searches were performed, and abstracts related to this topic from oncology and cardiology meetings were reviewed. Potential adverse effects of mediastinal irradiation are numerous and can include coronary artery disease, pericarditis, cardiomyopathy, valvular disease and conduction abnormalities. Damage appears to be related to dose, volume and technique of chest irradiation. Effects may initially present as subclinical abnormalities on screening tests or as catastrophic clinical events. Estimates of relative risk of fatal cardiovascular events after mediastinal irradiation for Hodgkin's disease ranges between 2.2 and 7.2 and after irradiation for left-sided breast cancer from 1.0 to 2.2. Risk is life long, and absolute risk appears to increase with length of time since exposure. Radiation-associated cardiovascular toxicity may in fact be progressive. Long-term cardiac follow-up of these patients is therefore essential, and the range of appropriate cardiac screening is discussed, although no specific, evidence-based screening regimen was found in the literature.
Irradiation of the heart incidental to the treatment of malignancies can cause a spectrum of cardiovascular complications. These include pericarditis, myocardial fibrosis, muscular dysfunction, valvular abnormalities, and conduction disturbances. Survivors of Hodgkin's disease and breast cancer survivors treated with radiotherapy after mastectomy appear to be the groups at highest risk for radiation-associated cardiovascular disease. Although modern techniques of chest radiotherapy have decreased its frequency by reducing the dose and volume of radiation exposure to the heart, survivors treated with radiation remain at increased risk of cardiovascular disease. The risk of fatal cardiovascular disease increases with younger age at treatment, longer follow-up, and higher dose volumes of exposure to the heart. Certain chemotherapeutic agents, such as anthracyclines, also increase the risk of damage to the heart. Cardiac damage associated with radiotherapy may be progressive. Screening of survivors may help identify those at highest risk for serious cardiovascular disease. The broad range of radiation-associated cardiovascular disease makes it necessary for survivors to be examined with multiple screening modalities, although data do not exist to support definitive recommendations on test frequency.
BACKGROUND: A shortcoming of the pediatric electrocardiogram (ECG) appears to be its inability to accurately detect left ventricular hypertrophy (LVH). This study prospectively assesses the usefulness of the pediatric ECG as a screening modality for LVH. METHODS: Concomitant echocardiograms and ECGs from a large cohort of children who were exposed to the human immunodeficiency virus (HIV; uninfected) and children who were infected with HIV were compared. By use of the values of Davignon et al, qualitative determination of LVH and quantitative criteria for LVH (RV6, SV1, RV6+SV1, QV6, and Q(III) >98% for age, R/SV1 <98% for age, and [-]TV6) were compared to body surface area adjusted for left ventricular (LV) mass z score. Results were then stratified according to weight and weight-for-height z scores. New age-adjusted predicted values were then constructed from children of a mixed race who were HIV-uninfected, < or =6 years old, and similarly assessed. RESULTS: The sensitivity rate was <20% for detecting increased LV mass, irrespective of HIV status; the specificity rate was 88% to 92%. The sensitivity rate of the individual criteria ranged from 0 to 35%; the specificity rate was 76% to 99%. Test sensitivities remained low when stratified by weight and weight-for-height z scores. Areas under the receiver operator characteristic curves were between 0.59 and 0.70, also suggesting poor accuracy of the ECG criteria. By use of new age-adjusted predicted values, the sensitivity rate decreased to <17%, and the specificity rate increased to 94% to 100%. CONCLUSION: The ECG is a poor screening tool for identifying LVH in children. Sensitivity is not improved with revision of current criteria.