The Dilated Cardiomyopathies: Clinical Aspects

Blood dendritic cell levels and phenotypic characteristics in relation to etiology of end-stage heart failure: implications for dilated cardiomyopathy

BACKGROUND

Dysregulation of dendritic cell (DC) mediated immune responses towards auto-antigens, is considered an important feature in the maintenance of experimentally induced heart failure (HF). In order to evaluate the role of blood DCs in cardiomyopathies of different origins, we examined myeloid (mDC) and plasmacytoid (pDC) subset levels and maturation characteristics, according to HF severity and etiology in humans.

METHODS

Absolute numbers of mDCs and pDCs in 12 New York Heart Association (NYHA) class-II, 28 NYHA class III-IV HF patients and 18 healthy controls, were studied by 4-colour whole blood flow cytometry.

RESULTS

End-stage (NYHA III-IV) HF patients had comparable circulating DC subset levels to NYHA-II patients and controls. However, within the NYHA III-IV group total DC levels in patients with non-ischemic dilated cardiomyopathy (DCM) were higher (P<0.001) than in patients with coronary artery disease (CAD), hypertrophic cardiomyopathy (HCM) or other HF etiology. This was due to a significant increase of primarily mDCs (P<0.0001) and to a lesser extent of pDCs (P<0.05) in idiopathic DCM patients, independent of systolic or diastolic cardiac dysfunction. Maturation marker CD83 and lymphoid homing chemokine receptor CCR7 surface expression was enhanced only on mDCs, but not pDCs from DCM patients (P<0.05), compared to patients with CAD, HCM or other underlying cardiac pathophysiology.

CONCLUSIONS

Total blood DC levels in end-stage HF are elevated in patients with DCM. Whole blood DC characterisation may lead to new insights into the pathophysiology of idiopathic DCM in humans.

Epidemiology of idiopathic cardiomyopathy in Qatar during 1996-2003

OBJECTIVES

To report the rates of cardiomyopathies in the population below 50 years of age in Qatar.

SUBJECTS AND METHODS

We conducted a retrospective review of clinical data on patients with cardiomyopathy who were hospitalized in Hamad General Hospital, Doha. Data were collected from medical records during the 1996-2002 period and prospectively from the patients who were hospitalized during the year 2003. All cardiomyopathy patients below 50 years of age who were citizens or permanent residents in Qatar were included in this study.

RESULTS

During the study period, a total of 132 cases were recorded with idiopathic cardiomyopathies. Among these, 67.4% were males and 32.6% females; Qatari 31.8%, non-Qatari 68.2%. The consanguinity rate was high among Qatari patients. In the first 7-year study period, 1996-2002, the incidence rate of all types of cardiomyopathies was 2.5/100,000 population per year (95% CI: 1.4-3.5). It increased to 5.2/100,000 population during the year 2003 (95% CI: 3.6-6.7). Dilated cardiomyopathy was most prevalent (75.8%) in all age groups, and the incidence increased remarkably with age. Lower prevalence of hypertrophic cardiomyopathy (13.6%) and left ventricle noncompaction cardiomyopathy (6.1%) was found. In children below 15 years of age, the incidence rate for all types of cardiomyopathies was 2.7/100,000 population. The overall mortality rate was 5.3%.

CONCLUSION

Most cases of cardiomyopathy were identified at an early age: below 15 years and above 35 years of age. Introducing preventive and early diagnosis programs may have an impact on reducing the mortality and morbidity from idiopathic cardiomyopathy.

Cardiac Transplantation

Heart transplantation is a treatment option available to patients with end-stage heart failure who meet standardized selection criteria for transplant. Through a rigorous evaluation process, professionals set out to establish the patient's severity of heart failure, screen for comorbidities that may negatively affect survival, and assess psychosocial variables necessary for successful outcomes following transplantation. Because of a limited donor organ supply, each of these factors must be examined carefully to assure that this scarce resource is used to its greatest potential benefit.

Idiopathic dilated cardiomyopathy in an Omani population of the Arabian Peninsula: prevalence, clinical profile and natural history

We have analysed prospectively the prevalence and clinical profile of idiopathic dilated cardiomyopathy (IDC) in a circumscribed native population of the Sultanate of Oman over 3 years (1992-1994). Identified patients were followed up for a period ranging from 1 to 8 years (median 4 years) and the variables related to outcome determined. IDC was diagnosed in 97 patients, giving a prevalence of 43.2/100,000 population during the study period. 84.5% of patients were aged over 35 years and males outnumbered females (M/F=1.4:1). Factors related to poor outcome were an initial left ventricular ejection fraction </=30% (P=0.01), severe symptoms, i.e. NYHA functional class III or IV at presentation (P=0.04), and significant ventricular tachycardia during follow up (P=0.02). However, multivariate regression analysis yielded only low LVEF as the predictor of poor outcome (P=0.01). When analysed from age of onset of symptoms, survival figures were 94% at 1 year (95% CI 88 to 99%), 76% at 5 years (95% CI 67 to 86%) and 68% at 8 years (95% CI 54 to 82%). Mean survival was 6.5 years (95% CI 6 to 7 years). Patients were still at risk of fatal ventricular arrhythmia even when haemodynamically stable and had left ventricular ejection fraction >30%.

Left ventricular thrombus and subsequent thromboembolism in patients with severe systolic dysfunction

STUDY OBJECTIVES

To determine the frequency of left ventricular (LV) thrombi by echocardiography and to define the predictors of LV thrombus and subsequent thromboembolism.

DESIGN

Retrospective case-control design.

SETTING

Single tertiary care center.

PATIENTS

Twenty-eight patients with LV thrombus in a consecutive series of 144 patients with severe LV dysfunction and follow-up period for a mean of 27.6 months.

MEASUREMENTS AND RESULTS

Thirty-five clinical and echocardiographic variables were evaluated. The mean age of patients with (n = 28) vs patients without (n = 116) LV thrombus was 50.3 +/- 11.0 years vs 54.2 +/- 11.1 years (p = 0.09), with 22 patients (78.6%) and 78 patients (67.2%) being male (p = 0.24), respectively. The mean ejection fraction (EF) for those with vs those without LV thrombus was 17.5 +/- 5.5 vs 20.0 +/- 6.9 (p = 0. 08), with 16 patients (57.1%) and 42 patients (36.2%) having an EF < 20% (p = 0.04), respectively. The groups were similar with respect to other baseline characteristics, comorbid illnesses, and drug therapies other than anticoagulants. All 28 patients with LV thrombus (100%) and 54 of those without LV thrombus (46.6%) were treated with warfarin. Ischemic etiology of the cardiomyopathy (odds ratio, 4.78; 95% confidence interval, 1.51 to 15.11; p = 0.008) and increased LV internal diastolic dimension (LVIDD; odds ratio, 1.10; 95% confidence interval, 1.03 to 1.18; p = 0.004) were found to be independent predictors of thrombus formation. Peripheral embolism occurred in 5 patients (17.9%) vs 13 patients (11.2%) of those with and without LV thrombi, respectively (p = 0.35). Ischemic etiology of the cardiomyopathy (odds ratio, 3.79; 95% confidence interval, 1. 13 to 12.64; p = 0.03) and EF (odds ratio, 0.91; 95% confidence interval, 0.82 to 1.00; p = 0.04) were found to be independent predictors of systemic embolization. The patients with an embolic event suffered a significantly higher mortality (7 of 18 patients; 38.9%) during the follow-up period when compared to those without an embolic event (13 of 126 patients; 10.3%; p < 0.0001).

CONCLUSIONS

We conclude that ischemic cardiomyopathy and dilated LV chamber sizes (LVIDD > 60 mm) are independently associated with LV thrombi. A peripheral embolic event is related to poor long-term survival in this patient group.

Effects of continuous positive airway pressure on cardiac volumes in patients with ischemic and dilated cardiomyopathy

The effects of continuous positive airway pressure (CPAP) on left (LV) and right ventricular (RV) volumes in patients with congestive heart failure (CHF) have not been studied. We hypothesized that CPAP would cause greater reductions in cardiac volumes in CHF patients with idiopathic dilated cardiomyopathy (IDC) than in those with ischemic cardiomyopathy (IsC), because their ventricles are more compliant. The effects of a 30-min CPAP application at 10 cm H(2)O on RV and LV end-diastolic (EDV) and end-systolic volumes (ESV), determined by radionuclide angiography, were therefore tested in 22 patients with CHF due to IsC (n = 13) or IDC (n = 9). CPAP-induced reductions in LVEDV, LVESV, RVEDV, and RVESV were significantly greater (p < 0.05) in the IDC than in the IsC group. Whereas in the IsC group CPAP caused no significant changes in LV or RV volumes, in the IDC group it induced significant reductions in RVEDV (527 +/- 77 ml to 354 +/- 50 ml, p = 0.03) and RVESV (400 +/- 78 ml to 272 +/- 54 ml, p = 0.04) that were greater than any reductions in LVEDV and LVESV. We conclude that CPAP causes greater short-term reductions in RV and LV volumes in CHF patients with IDC than in those with IsC, and that among patients with IDC, CPAP causes greater reductions in RV than in LV volumes.

Comparison of mortality rates and progression of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy and dilated versus nondilated right ventricular cavities

This study assesses the influence of right ventricular (RV) dilation on the progression of left ventricular (LV) dysfunction and survival in patients with idiopathic dilated cardiomyopathy (IDC). Using transthoracic echocardiography, we studied 100 patients with IDC aged 20 to 80 years (mean 55 +/- 14); 67% were men. In the apical 4-chamber view, diastolic LV and RV chamber area measurements classified patients into 2 groups: group RV enlargement+ (RV area/LV area > 0.5) included 54 patients; group RV enlargement- (no RV enlargement) had RV area/LV area < or = 0.5. Echocardiographic studies were repeated in all patients after a mean of 33 +/- 16 months. At the time of the initial study, the 2 groups did not differ in age, gender, incidence of atrial fibrillation and diabetes, left ventricular mass, and LV ejection fraction, but the RV enlargement+ group had more severe tricuspid regurgitation and less LV enlargement. After 47 +/- 22 months (range 12 to 96), patients in group RV enlargement+ had lower LV ejection fraction (29% vs 34%, p = 0.006) than patients with initial RV enlargement-. At clinical follow-up, mortality was higher (43%) in patients with initial RV enlargement+ than the RV enlargement- patients (15%), p = 0.002. For survivors, the mitral deceleration time averaged 157 +/- 36 ms; for nonsurvivors or patients who required transplant, the mitral deceleration time averaged 97 +/- 12 ms (p < 0.0001). With use of a multivariate Cox model adjusting for LV ejection fraction, LV size, and age, the relative risk ratio of mortality from initial RV enlargement+ was 4.4 (95% confidence limits 1.7 to 11.1) (p = 0.002). Thus, patients with significant RV dilation had nearly triple the mortality over 4 years and more rapidly deteriorating LV function than patients with less initial RV dilation. In IDC, RV enlargement is a strong marker for adverse prognosis that may represent a different morphologic subset.

Prevalence of echocardiographic findings in 554 men and in 1,243 women aged > 60 years in a long-term health care facility

The prevalence of mitral regurgitation, valvular aortic stenosis, aortic regurgitation, hypertrophic cardiomyopathy, idiopathic dilated cardiomyopathy, and of left ventricular hypertrophy was not significantly different in older men and women. Older women had a significantly higher prevalence of rheumatic mitral stenosis, mitral annular calcium, and left atrial enlargement than older men, and older men had a significantly higher prevalence of abnormal left ventricular ejection fraction than older women.

Discordance in degree of right and left ventricular dilation in patients with dilated cardiomyopathy: recognition and clinical implications

OBJECTIVES

The purpose of the present study was to assess the influence of variations in the relative degree of dilation of left and right ventricular chambers on the clinical outcome of patients with dilated cardiomyopathy.

BACKGROUND

Dilated cardiomyopathy, a primary myocardial disease characterized by ventricular dilation and systolic dysfunction, is generally associated with a poor prognosis. However, considerable variability has been observed in the clinical course and the morphologic and hemodynamic features in individual patients.

METHODS

We evaluated 67 consecutive patients with dilated cardiomyopathy and without evidence of ischemic or primary valvular heart disease. On the basis of diastolic ventricular chamber area measurements obtained by echocardiography, patients were classified into two groups: 38 patients with a relatively equal degree of left and right ventricular dilation (LV congruent to RV) and 29 patients with predominant and disproportionate dilation of the left ventricle (LV > RV).

RESULTS

The 67 patients ranged in age from 19 to 81 years (mean 56); 49 (73%) were male. The two subsets of patients with dilated cardiomyopathy did not differ with regard to age, left ventricular diastolic dimension, wall thickness and mass or ejection fraction. However, patients in the LV congruent to RV group showed more severe mitral and tricuspid regurgitation by Doppler echocardiography than did those in the LV > RV group (p = 0.01 for mitral and 0.004 for tricuspid regurgitation). Over the follow-up period of 2 to 60 months (mean 28), there were 19 deaths. Survival in the LV > RV group was significantly better than in the LV congruent to RV group (p = 0.03).

CONCLUSIONS

Patients with dilated cardiomyopathy represent a heterogeneous group with regard to both clinical outcome and the relative degree of left and right ventricular chamber dilation. Patients in the LV > RV subset appear to have better overall survival and less severe mitral and tricuspid regurgitation than do patients in the LV congruent to RV subset. Longitudinal studies are needed to determine whether these morphologic subsets in fact represent a continuum within the disease spectrum of dilated cardiomyopathy.

Current expectations in dynamic cardiomyoplasty

Dynamic cardiomyoplasty has been evaluated in the treatment of severe cardiomyopathies. This report outlines the results of this procedure in 21 patients with dilated or ischemic cardiomyopathy who were in New York Heart Association class III or IV before operation. There were no operative deaths. Patients were followed up for a mean of 17.6 months. Eight patients died during late follow-up, and actuarial survival rates were 73.2% at 1 year and 65.9% at 2 years of follow-up. Functional class improvement was documented in the surviving patients. Furthermore, significant improvement in left ventricular function was demonstrated by radioisotopic angiography and by heart catheterization for more than 2 years after the operation. These studies documented that left ventricular ejection fraction increased as a result of global improvement in regional wall motion. Absence of clinical and hemodynamic improvement after cardiomyoplasty seems to be related to muscle flap ischemic compromise, whereas the patient's condition before operation seems to influence the long-term outcome of cardiomyoplasty.

Ventricular thrombi and thromboembolism in dilated cardiomyopathy: a prospective follow-up study

To determine the prevalence and natural history of left ventricular thrombus in dilated cardiomyopathy, we prospectively performed two-dimensional echocardiograms in 25 patients with nonischemic dilated cardiomyopathy who were not receiving anticoagulation. Eighty-five echocardiograms were performed serially over a 9- to 30-month period (mean follow-up 21.5 months). A left ventricular thrombus was present on initial echocardiogram in 11 (44%) patients, became present during follow-up in an additional four, and disappeared in two. Thrombus was significantly more common in patients with fractional shortening of less than or equal to 10% (12 of 15) than in those with a fractional shortening 11% to 25% (3 of 10) (p less than 0.02). Five embolic events (four cerebral) occurred over the follow-up period, four of which were associated with a previously visualized left ventricular thrombus. Three of five thrombi that protruded into the left ventricular cavity subsequently embolized. We conclude that in nonanticoagulated patients with dilated cardiomyopathy left ventricular thrombus and thromboembolism are common. Echocardiography may be helpful in predicting which patients are at risk of thromboembolism.