Prognostic value of echocardiography in children with idiopathic dilated cardiomyopathy

Variability of M-mode versus two-dimensional echocardiography measurements in children with dilated cardiomyopathy

M-mode and 2-dimensional (2D) echocardiographic imaging are routinely used to quantify left-ventricular (LV) size and function in pediatric patients with dilated cardiomyopathy (DCM). The reproducibility of and correlation between these techniques are unknown. This analysis sought to compare interreader, intrareader, and interacquisition reproducibility of M-mode versus 2D measurements in pediatric DCM patients. The Ventricular Volume Variability study of the Pediatric Heart Network is a multicenter, prospective, observational study assessing the course of chronic DCM in children. Two sonographers performed baseline image acquisitions locally, and two readers performed measurements at the echocardiographic core laboratory. One reader repeated measurements 1 month later. These data were used to assess reproducibility and agreement between M-mode and 2D measurements. One hundred sixty-nine subjects were enrolled. M-mode had similar or greater reproducibility in both intrareader and interreader settings for LV dimensions, shortening fraction (SF), and most wall thicknesses. In contrast, 2D reproducibility was similar or better for nearly all variables in the interacquisition setting but not for SF. Interacquisition variability was approximately twice the intrareader variability. LV dimensions by either modality consistently had high reproducibility and had the highest agreement between modalities. In pediatric DCM patients, variability of linear echocardiographic assessment could be minimized by relying on a single reader and using a consistent method (M-mode or 2D) for serial measurements, preferably M-mode when SF is the primary variable of interest. Except for LV dimensions, M-mode and 2D values should not be used interchangeably due to poor agreement.

Long-Term Outcomes of Dilated Cardiomyopathy Diagnosed During Childhood

Background—

Existing studies of childhood dilated cardiomyopathy deal mainly with early survival. This population-based study examines long-term outcomes for children with dilated cardiomyopathy.

Methods and Results—

The diagnosis of dilated cardiomyopathy was based on clinical, echocardiographic, and pathological findings. The primary study end point included time to the combined outcome of death or cardiac transplantation. There were 175 patients 0 to <10 years of age at the time of diagnosis. Survival free from death or transplantation was 74% (95% confidence interval, 67–80) 1 year after diagnosis, 62% (95% confidence interval, 55–69) at 10 years, and 56% (95% confidence interval, 46–65) at 20 years. In multivariable analysis, age at diagnosis <4 weeks or >5 years, familial cardiomyopathy, and lower baseline left ventricular fractional shortening Z score were associated with increased risk of death or transplantation, as was lower left ventricular fractional shortening Z score during follow-up. At 15 years after diagnosis, echocardiographic normalization had occurred in 69% of surviving study subjects. Normalization was related to higher baseline left ventricular fractional shortening Z score, higher left ventricular fractional shortening Z score during follow-up, and greater improvement in left ventricular fractional shortening Z score. Children with lymphocytic myocarditis had better survival and a higher rate of echocardiographic normalization. At the latest follow-up, 100 of 104 of survivors (96%) were free of cardiac symptoms, and 83 (80%) were no longer receiving pharmacotherapy.

Conclusions—

Death or transplantation occurred in 26% of patients with childhood dilated cardiomyopathy within 1 year of diagnosis and ~1% per year thereafter. Risk factors for death or transplantation include age at diagnosis, familial cardiomyopathy, and severity of left ventricular dysfunction. The majority of surviving subjects are well and free of cardiac medication.

Anaemia is a predictor of early death or cardiac transplantation in children with idiopathic dilated cardiomyopathy

INTRODUCTION

The aim of our study was to establish the prevalence and the prognostic value of haematological abnormalities in children with cardiac failure.

PATIENTS AND METHODS

A series of 218 consecutive children with a first diagnosis of idiopathic dilated cardiomyopathy were retrospectively examined. Haematological evaluation was performed at first diagnosis. Death or cardiac transplantation was the main outcome measure.

RESULTS

The median age was 0.6 years, ranging from 1 day to 15.8 years and median follow-up was 2.65 years, ranging from 0 to 17.2 years. After a median interval of 0.2 years, ranging from 0 to 8.7 years, 56 patients died and 25 were transplanted. Event-free survival at 1 and 5 years was 68% (95% confidence interval, 63-75%) and 62% (95% confidence interval, 56-69%). Blood levels of haemoglobin less than 10 grams per decilitre, urea over 8 millimoles per litre, and C-reactive protein over 10 milligrams per litre were found in 24%, 20%, and 24% of patients, respectively. The log-rank test showed that haemoglobin (p = 0.000) and C-reactive protein (p = 0.021) were predictors of death or transplantation. In the multivariate Cox model, haemoglobin (hazard ratio = 0.735; confidence interval = 0.636-0.849; p = 0.000) and urea (hazard ratio = 1.083; confidence interval = 1:002-1:171; p = 0.045) were predictive of poor outcome. Cubic spline functions showed that the positive role of haemoglobin on survival was linear for values less than 12 grams per decilitre and null for values more than 12 grams per decilitre. Adaptive index models for risk stratification and Classification and Regression Tree analysis allowed to identify the cut-off values for haemoglobin (less than 10.2 grams per decilitre) and urea (more than 8.8 millimoles per litre), as well as to derive a predictor model.

CONCLUSIONS

In children with idiopathic dilated cardiomyopathy, anaemia is the strongest independent prognostic factor of early death or transplantation.

Myocardial Doppler velocities as a marker of prognosis in the ICU

Relatively simple measures of echocardiography and Doppler, as left ventricular end-systolic area and volume, should be taken in consideration when performing a Doppler echocardiographic examination, as they could have both clinical and prognostic value.

Outcome Predictors for Pediatric Dilated Cardiomyopathy: A Systematic Review

Dilated cardiomyopathy comprises the largest group of pediatric cardiomyopathy functional types and is the most common indication for heart transplant in children over 5 years old. Prognostic factors for this condition have long been sought by many researchers. In a systematic review of these factors, we found 32 relevant articles published since 1976. Four studies report finding no predictive factors. In the remaining 28 studies, several factors indicating better prognosis stand out across multiple articles: younger age at diagnosis, higher left-ventricular fractional shortening and ejection fraction, and the presence of myocarditis. Results for other factors conflict across studies: severe mitral regurgitation, arrhythmias, and a family history of cardiomyopathy. Elevated left-ventricular end diastolic pressure was statistically significant in two studies, but it may be of limited utility as a result of its invasiveness. Although most children have congestive heart failure at presentation, only two studies found it to be a significant predictor of mortality. The largest study of this factor qualified the increased risk to 1 year after presentation. Other significant predictors that have not been analyzed or reported by more than one study group, are right ventricular failure and impaired cardiac adrenergic innervation, as detected by radiolabeled meta-iodobenzylguanidine imaging. Although 1- and 5-year survival rates have steadily improved, as more children with DCM receive cardiac transplants, event-free survival rates (the absence of "heart death" resulting in death or transplant) are similar to those from decades ago. A unified risk algorithm may assist in clinical decision-making but requires more studies. Other studies are needed to assess the post-transplant survival experience.

Outcome factors of idiopathic dilated cardiomyopathy in children - a long-term follow-up review

BACKGROUND

Idiopathic dilated cardiomyopathy in children has a high rate of mortality. Cardiac transplantation is the treatment of choice in those who fail to respond to therapeutics. Several studies have been carried out to determine unfavourable prognoses, and to provide an early indication for cardiac transplantation. Nevertheless, no consensus has been reached on the matter.

OBJECTIVE

To propose predictors of death in children with idiopathic dilated cardiomyopathy.

METHODS

We reviewed data extending over 22 years from 142 consecutive children with idiopathic dilated cardiomyopathy, of whom 36 died. The criteria for inclusion were the presence of congestive heart failure or cardiomegaly in a routine chest X-ray, confirmed by enlargement and hypo kinesis of the left ventricle in the echocardiogram. We included asymptomatic children in functional class I. Based on Cox's analysis of clinical and laboratory data, we sought any predictors of death.

RESULTS

In univariate analysis, the predictors were functional class IV at presentation (p equal to 0.0001), dyspnoea (p equal to 0.0096), and reduced pedal pulses (p equal to 0.0413). In chest X-ray, they were maximal cardiothoracic ratio (p equal to 0.0001) and pulmonary congestion (p equal to 0.0072). In the electrocardiogram, right atrium overload (p equal to 0.0118), ventricular arrhythmias (p equal to 0.0148) and heart rate (p equal to 0.027). In the echocardiogram, mitral regurgitation of grade 3 to 4 (p equal to 0.002), the left atrial to aortic ratio (p equal to 0.0001), and left ventricle ejection fraction (p equal to 0.0266). In multivariate analysis, the independent predictors were maximum cardiothoracic ratio (p equal to 0.0001), left ventricle ejection fraction (p equal to 0.0013), mitral regurgitation of grade 3 or 4 (p equal to 0.0017), functional class IV at presentation (p equal to 0.0028), and ventricular arrhythmias (p equal to 0.0253).

CONCLUSION

Children, who have these predictors of death should be considered for early heart transplantation when no improvement is observed in clinical treatment.

Indications for Heart Transplantation in Pediatric Heart Disease

Background— Since the initial utilization of heart transplantation as therapy for end-stage pediatric heart disease, improvements have occurred in outcomes with heart transplantation and surgical therapies for congenital heart disease along with the application of medical therapies to pediatric heart failure that have improved outcomes in adults. These events justify a reevaluation of the indications for heart transplantation in congenital heart disease and other causes of pediatric heart failure.

Methods and Results— A working group was commissioned to review accumulated experience with pediatric heart transplantation and its use in patients with unrepaired and/or previously repaired or palliated congenital heart disease (children and adults), in patients with pediatric cardiomyopathies, and in pediatric patients with prior heart transplantation. Evidence-based guidelines for the indications for heart transplantation or retransplantation for these conditions were developed.

Conclusions— This evaluation has led to the development and refinement of indications for heart transplantation for patients with congenital heart disease and pediatric cardiomyopathies in addition to indications for pediatric heart retransplantation.

Echocardiographic predictors of adverse clinical events in children with dilated cardiomyopathy: a prospective clinical study

OBJECTIVES

To compare tissue Doppler (TD) velocities between patients with dilated cardiomyopathy (DCM) and normal controls and to determine whether TD velocities, Tei index, right ventricular fractional area change, and left ventricular ejection fraction (LVEF) predict adverse clinical outcomes in children with DCM.

METHODS

Prospective evaluation of children with DCM.

RESULTS

54 children with DCM and 54 age and sex matched control group participants were studied. Mitral inflow velocities were similar for both groups except for decreased mitral deceleration time in patients with DCM. Systolic and diastolic TD velocities at the mitral annulus (septal and lateral sides) and tricuspid annulus were significantly reduced in children with DCM compared with controls (p < 0.001 for each). By multivariate analysis, after adjustment for Tei index and right ventricular fractional area change, decreased LVEF and tricuspid velocity during early diastole (Ea) were predictors of the primary end point (PEP), a composite end point consisting of need for hospitalisation or the outcome transplantation or death. Tricuspid Ea velocity < 8.5 cm/s had 87% specificity and 60% sensitivity for reaching the PEP. LVEF < 30% had 68% specificity and 74% sensitivity for the PEP. Combined LVEF < 30% and tricuspid Ea < 11.5 cm/s had 100% specificity and 44% sensitivity for the PEP.

CONCLUSIONS

Children with DCM have significantly lower TD velocities than normal controls. In such cases, lower LVEF (< 30%) is more sensitive but less specific than lower tricuspid Ea velocities (< 8.5 cm/s) in predicting which patients are at risk of hospitalisation, transplantation, or death.

Carvedilol in children with cardiomyopathy: 3-year experience at a single institution

BACKGROUND

Carvedilol reduces mortality and hospitalization in adults with congestive heart failure. Limited information is available about its use in children.

METHODS

We reviewed the medical records of 24 children with dilated cardiomyopathy and left ventricular ejection fraction of <or=40%, who were treated with carvedilol as adjunct therapy to angiotensin-converting enzyme inhibitors, digoxin and diuretics.

RESULTS

Carvedilol was initiated 14.3 +/- 23.3 (mean +/- SD) months after the diagnosis of cardiomyopathy. Mean age at initiation of therapy was 7.2 +/- 6.4 years. The mean initial and maximum doses were 0.15 +/- 0.09 and 0.98 +/- 0.26 mg/kg/day. Adverse effects occurred in 5 patients (21%). Two patients (8%) required discontinuation of the drug within 5 weeks of the initial dose. The remaining 22 patients tolerated carvedilol for a mean follow-up period of 26.6 +/- 14.7 months. Among these 22 patients, mean left ventricular ejection fraction improved from 24.6 +/- 7.6% to 42.2 +/- 14.2% (p < 0.001), and mean sphericity index from 0.86 +/- 0.11 to 0.74 +/- 0.10 (p < 0.001). New York Heart Association functional class improved in 15 patients (68%). One patient (4%) died and 3 (14%) were transplanted.

CONCLUSIONS

Carvedilol, in addition to standard therapy for dilated cardiomyopathy in children improves cardiac function and symptoms; it is well tolerated, with minimal adverse effects, but close monitoring is necessary as it might worsen congestive heart failure and precipitate asthma. Control studies are necessary to assess the effect of carvedilol on mortality and hospitalization rates.

Carvedilol as therapy in pediatric heart failure: an initial multicenter experience

OBJECTIVE

The objective was to determine the dosing, efficacy, and side effects of the nonselective beta-blocker carvedilol for the management of heart failure in children.

STUDY DESIGN

Carvedilol use in addition to standard medical therapy for pediatric heart failure was reviewed at 6 centers.

RESULTS

Children with dilated cardiomyopathy (80%) and congenital heart disease (20%), age 3 months to 19 years (n = 46), were treated with carvedilol. The average initial dose was 0.08 mg/kg, uptitrated over a mean of 11.3 weeks to an average maintenance dose of 0.46 mg/kg. After 3 months on carvedilol, there were improvements in modified New York Heart Association class in 67% of patients (P =.0005, chi2 analysis) and improvement in mean shortening fraction from 16.2% to 19.0% (P =.005, paired t test). Side effects, mainly dizziness, hypotension, and headache, occurred in 54% of patients but were well tolerated. Adverse outcomes (death, cardiac transplantation, and ventricular-assist device placement) occurred in 30% of patients.

CONCLUSIONS

Carvedilol as an adjunct to standard therapy for pediatric heart failure improves symptoms and left ventricular function. Side effects are common but well tolerated. Further prospective study is required to determine the effect of carvedilol on survival and to clearly define its role in pediatric heart failure therapy.

Outcomes for children with cardiomyopathy awaiting transplantation

OBJECTIVE

To determine factors associated with outcomes after listing for transplantation in children with cardiomyopathies.

BACKGROUND

Childhood cardiomyopathies form a heterogeneous group of diseases, and in many, the prognosis is poor, irrespective of the etiology. When profound heart failure develops, cardiac transplantation can be the only viable option for survival.

METHODS

We included all children with cardiomyopathy listed for transplantation between 12/89 and 4/98 in this historical cohort study.

RESULTS

We listed 31 patients, 15 male and 16 female, 27 with dilated and 4 with restrictive cardiomyopathy, for transplantation. The median age at listing was 5.7 years, with a range from fetal life to 17.8 years. Transplantation was achieved in 23 (74%), with a median interval from listing of 54 days, and a range from zero to 11.4 years. Of the patients, 14 were transplanted within 30 days of listing. Five patients (16%) died before transplantation. Within the Canadian algorithm, one of these was in the third state, and four in the fourth state. One patient was removed from the list after 12 days, having recovered from myocarditis, and two remain waiting transplantation after intervals of 121 and 476 days, respectively. Patients who died were more likely to be female (5/5 vs. 11/26; p=0.04) and to have been in the third or fourth states at listing (5/5 vs. 15/26; p=0.04). The use of mechanical ventricular assistance, in 10 patients, was not a predictor of an adverse outcome. While not statistically significant, survival to transplantation was associated with treatment using inhibitors of angiotensin converting enzyme, less mitral regurgitation, a higher mean ejection fraction and cardiac index, and lower right ventricular systolic pressure.

CONCLUSIONS

Children with cardiomyopathy awaiting transplantation have a mortality of 16% related to their clinical state at the time of listing.

Late recovery of ventricular function in children with idiopathic dilated cardiomyopathy

BACKGROUND

The prognosis for children with idiopathic dilated cardiomyopathy (IDC) is variable. Patients who fail to exhibit improvement in left ventricular (LV) function have a high 1-year mortality rate, whereas improvement in LV fractional shortening (LVFS) to >15% is associated with better survival. However, complete recovery of LV performance to normal has not been examined.

METHODS AND RESULTS

The clinical features and echocardiograms of 63 children with IDC were reviewed. Sixteen patients (group 1) were identified who demonstrated progressive improvement in LVFS, ultimately recovering to within the normal range. They were compared with 47 patients (group 2) in whom LVFS remained depressed. Group 1 LVFS at first examination was 13.6% +/- 5.1%, z = -10.8 +/- 4.0, and improved to within the normal range (33.7% +/- 3.4%, z = -0.9 +/- 1. 4, P <.001). Group 2 initial LVFS was 13.6 +/- 2.3, z = -8.9 +/- 3.2 and did not change significantly (15.7% +/- 7.3%, z = -7.3 +/- 1.6). The LV was dilated at initial examination in all patients (z = 6.9 +/- 3.0). Recovery in group 1 was associated with a decrease in LV dimension to within the normal range (z = 1.3 +/- 1.6, P <.001), whereas the LV dimension in group 2 patients remained increased (z = 6.2 +/- 3.4). The mean follow-up time at which LV function was noted to be normal was 4.5 +/- 3.6 years (range 0.3 to 14 years). The total duration of follow-up was 6.5 +/- 5.2 years (range 1 to 16 years).

CONCLUSIONS

Complete recovery of LV function is possible in children with IDC. Recovery may occur within the first year after initial examination in some patients, but longer periods are needed in the majority of patients in whom LV function ultimately returned to normal.

Pediatric echocardiography: applications and limitations

Echocardiography is an extraordinarily useful imaging technique in fetuses, infants, children, and adolescents. Recent technologic innovations have expanded its versatility in the pediatric population. However, limited societal resources, limitations inherent to ultrasound imaging, and numerous imaging options even within the field of pediatric echocardiography necessitate the discriminate and thoughtful use of echocardiography in children. The clinical assessment remains a critical prelude to echocardiographic examination of the pediatric cardiovascular system.

Genetic basis of cardiomyopathy

The molecular basis of cardiac growth and development is a fundamental question that has intrigued many investigators in cardiovascular research. Adult cardiomyocytes are terminally differentiated and lose their ability to proliferate shortly after birth; however, in response to injury, myocytes have the capacity to synthesize new DNA and exhibit plasticity by a compensatory growth response, as is shown by re-expression of the fetal isoforms of many muscle-specific genes, which is characteristic of the proliferative response. The long-term effects of these compensatory responses may lead to the development and progression of diseases such as hypertrophic cardiomyopathy and dilated cardiomyopathy, because of a single point mutation. This concept has engaged scientists to investigate human models to explore the molecular basis of hypertrophy or dilation of the myocardium.

Pediatric myocardial disease

Cardiomyopathies are diseases of the heart muscles. This article reviews the causes, clinical presentation, diagnosis, management, and long-term outcomes of dilated and hypertrophic cardiomyopathy.

Left bundle branch block in infants with dilated cardiomyopathy conveys a poor prognosis

We describe three infants <3 months of age seen consecutively with dilated cardiomyopathy who presented initially with left bundle branch block on the surface 12-lead electrocardiogram. Each infant subsequently had a poor outcome: two died and one required heart transplantation. These results suggest that the presence of left bundle branch block on the 12-lead electrocardiogram conveys a poor prognosis in infants with dilated cardiomyopathy.

New theories. Causes of dilated cardiomyopathy

Dilated cardiomyopathy is a heterogeneous disease, both clinically and genetically. Two genes responsible for X-linked DCM have been identified. Five genetic loci responsible for X-linked DCM have been identified. Five genetic loci responsible for autosomal dominant DCM have also been mapped but no genes identified so far. New paradigms may be necessary in order to elucidate the etiology of primary dilated cardiomyopathy.

Assessment of left ventricular function: comparison between radionuclide angiography and semiquantitative two-dimensional echocardiographic analysis

Measurement of global left ventricular function is important in the follow-up of cardiac patients and is a good prognostic indicator in acute cardiac situations. We compared quantitative measurements of global left ventricular function made with radionuclide angiography (RNA) and contrast cardiac ventriculography (CVG) to visual semiquantitative estimates from two-dimensional echocardiographic images (2D-echo). Three hundred and thirty-nine consecutive patients who underwent RNA were assessed with 2D-echo within 3 months. In addition, 92 of these patients also underwent CVG (correlation of ejection fraction between CVG and RNA: r=0.82; P<0.0001). The RNA mean ejection fractions in the four 2D-echo groups (0=normal, 1=slightly, 2=moderate, or 3=severe reduced left ventricular function) differed markedly (P<0.0001); however, there was overlapping among the groups (2D-echo score/RNA ejection fraction: 0=57.3%+/-12.8%; 1=46.0%+/-12.9%; 2=29.6%+/- 12.2%; and 3=24.6%+/-11. 5%) and the difference between 2D-echo scores 2 and 3 was not significant. 2D-echo showed a good concordance in RNA classes (0=>/=505; 1=35%-49%; 2=21%-34%; and 3=</=20% ejection fraction) 0 (133/166; 80%) and 3 (18/30; 60%) but low concordance in classes 1 (27/82; 33%) and 2 (21/61; 34%). For accurate assessment of global left ventricular ejection fraction, visual semiquantitative judgement of a 2D echocardiographic image is limited in comparison to CVG or RNA, especially in patients with a slight or moderate reduction in left ventricular ejection fraction.

Gene mapping of familial autosomal dominant dilated cardiomyopathy to chromosome 10q21-23

Dilated cardiomyopathy (DCM) is the most common form of primary myocardial disorder, accounting for 60% of all cardiomyopathies. In 20-30% of cases, familial inheritance can be demonstrated; an autosomal dominant transmission is the usual type of inheritance pattern identified. Previously, genetic heterogeneity was demonstrated in familial autosomal dominant dilated cardiomyopathy (FDCM). Gene localization to chromosome 1 (1p1-1q1 and 1q32), chromosome 3 (3p25-3p22), and chromosome 9 (9q13-9q22) has recently been identified. We report one family with 26 members (12 affected) with familial autosomal dominant dilated cardiomyopathy in which linkage to chromosome 10 at the 10q21-q23 locus is identified. Using short tandem repeat polymorphism (STR) markers with heterozygosity > 70%, 169 markers (50% of the genome) were used before linkage was found to markers D10S605 and D10S201 with a pairwise LOD score = 3.91, theta = 0, penetrance = 100% for both markers. Linkage to 1p1-1q1, 1q32, 3p25-3p22, and 9q13-9q22 was excluded. We conclude that a new locus for pure autosomal dominant FDCM exists, and that this gene is localized to a 9 cM region of 10q21-10q23. The search for the disease causing gene and the responsible mutation(s) is ongoing.