The natural history of dilated cardiomyopathy--a community study

[Epidemiological study of the idiopathic dilated cardiomyopathy in Tunisia]

AIMS OF THE STUDY

Idiopathic dilated cardiomyopathy (IDC) is a complex disease. The interest of this study were to investigate the epidemiology characteristics of the disease and to evaluate the prognostic echocardiographic markers by region in order to highlight the existence of genetic risk factors and/or environmental and to identify those patients who could benefit from early treatment and better care to avoid further complications of the disease.

PATIENTS AND METHODS

This is a retrospective study based on the Fischer exact and bilateral Mann-Whitney test.

RESULTS

We included 526 patients with dilated cardiomyopathies of them we detected 50 cases of IDC including 12 families: The average age was 39,3±15.2 years. The sex ratio was 2.6. Mean left ventricular end-diastolic diameter (DIVGd) was higher in patients from the North East region (44.3±6.2mm/m(2)). Using Receiver Operating Characteristics (ROC) curve, we found a threshold value of 40mm/m(2). The odds ratio associated with this cutoff was 9.2.

CONCLUSION

Our results suggest that the prevalence and severity of IDC were higher in the North East region of Tunisia. Furthermore, large-scale prospective studies are needed to confirm these findings. In confirmation of a higher prevalence, a genetic study should be undertaken in this region.

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%.

Predictors of coronary angiography in patients with idiopathic dilated cardiomyopathy: the Washington, DC Dilated Cardiomyopathy Study

Although a number of clinical and demographic factors have been associated with the performance of angiography in cardiac patients, clinical studies of idiopathic dilated cardiomyopathy (DCM) have often excluded patients who have not undergone coronary angiography to rule out coronary artery disease (CAD). To examine the impact of this diagnostic criterion on population-based studies of idiopathic DCM, we examined characteristics of probable cases of DCM who did or did not have a recorded history of angiography. The cases (n = 129) were ascertained from five medical centers in the Washington, DC metropolitan area over the period 1 July 1990 through 29 February 1992. All of these cases had evidence of ventricular dilation and hypokinesis, with a left ventricular ejection fraction of less than 40%. Cases with a history of known CAD, congenital heart disease, valvular heart disease, or secondary cardiomyopathy were excluded. Sixty-two (48%) of the cases had a recorded history of angiography. Age, educational level, diabetes, alcohol use, insurance status, and type of hospital were significantly associated with angiography in bivariate analysis (p < 0.05). Diabetes and hypertension were inversely associated with history of angiography among black cases, and positively associated with angiography among whites. In logistic regression analysis, age was the strongest independent predictor of angiography (p < 0.025). The associations with educational attainment and alcohol use were of borderline significance (p < 0.10). Thus, in epidemiologic studies of idiopathic DCM, particularly in biracial populations, the exclusion of cases who have not undergone angiography may bias risk estimates and result in the underestimation of incidence and prevalence.

Descriptive epidemiology of idiopathic dilated cardiomyopathy in Washington County, Maryland, 1975-1991

Estimates of the incidence of idiopathic dilated cardiomyopathy (IDC) were obtained by identifying cases from Washington County, Maryland who were hospitalized at local and regional hospitals over a recent 17 year period. All of the verified cases had evidence of ventricular dilatation and hypokinesis, with a left ventricular ejection fraction of less than 40%. A total of 26 cases were hospitalized over the period 1975-1991. The average age of the cases at the time of diagnosis was 55.5 years (range 22-80 years of age). About 58% of the subjects were males. A marked increase in newly diagnosed cases of IDC occurred in this population in recent years; 38% of the cases (10 of 26) were newly diagnosed during 1991 alone. Over the period 1975-1991, the average annual incidence rate of hospitalized cases was 1.6 per 100,000 among men and 1.2 per 100,000 among women. During the last 7 years of the case ascertainment period (1985-1991), the average annual incidence rate was 3.5 per 100,000 among men and 2.5 per 100,000 among women. These results provide additional evidence that IDC is being increasingly recognized by clinicians, and underscore the need for an improved understanding of the distribution and determinants of this often fatal condition.