A clinical study of idiopathic dilated cardiomypathy in an Omani population

This is a clinical study of idiopathic dilated cardiomyopathy (IDC) in an Omani population. Clinical data in this condition has been lacking in Arabia. 1164 patients with heart failure referred to the only secondary care hospital in the Dhakliya region of Oman were evaluated. This region has an indigenous adult population of 225,000 over 12 years of age.;Over a three-year period, 1992 to 1994, 97 patients with idiopathic dilated cardiomyopathy were identified, with a median age of 50 years (range 15 to 69) giving an yearly prevalence of 14.4/100,000. There was a male predominance of 1.4/1. Parental consanguinity was high (30%) but among the 770 (87%) first-degree relatives screened, cases of IDC were found to be few (6.5%). Familial cases were younger at presentation and more often had consanguineous parents. Familial and sporadic forms did not differ in survival. There was no HLA-DR4 association and cardiac specific antibodies were not detected making an autoimmune pathophysiology unlikely in these patients. During a mean follow-up period of 6 years (1 to 8 years) survivals were 94% at 1 year, 76% at 5 years, and 68% at 8 years with a mean overall survival of 9.8 years. As a predictor of poor outcome, severe dyspnoea (NYHA classes III & IV) at presentation, ventricular tachycardia and severe mitral regurgitation were significant on univariate analysis but left ventricular ejection fraction was the only significant factor identified by multivariate analysis. Plasma noradrenaline levels were elevated but did not correlate with the severity of the disease. In children with short duration of illness, such a correlation however, was evident. Mild coronary artery disease was present in 6.3% of cases at angiography but had not correlation with mortality.;No aetiopathogenic mechanisms could be identified and alcohol consumption was not involved. 75% of the patients were from a low socio-economic background. This needs further evaluation. With the completion of this report further research is ongoing into the genetics and autoimmunity of IDC in the Omani population, with studies being extended to other regions of Oman to collect data at a national level.