RESUMEN
Patients of chronic exudative pericardial effusion are frequently treated with antitubercular treatment on presumptive grounds in developing countries, in a hope to prevent constrictive pericarditis. To assess the impact of antitubercular treatment on development of constrictive pericarditis in chronic large exudative pericarditis effusion of undetermined etiology, 25 patients above 12 years of age, with large pericarditis effusion beyond 12 weeks duration, were randomized in a prospective 2:1 fashion, to receive either 3-drug antitubercular treatment (group A) or placebo (group B) for six months. End points studied were, development of pericardial thickness as diagnosed by CT scan and constrictive pericarditis as diagnosed by cardiac catheterization. Twenty-one patients (14 in group A and 7 in group B) completed the study protocol. In all, five (23.8%) patients developed constrictive pericarditis/pericardial thickening. Histopathological examination of pericardiectomy specimens in over five patients were negative for tubercular pathology. Pericardial effusion resolved completely in another 10 (47.8%) patients. There was no significant difference in both the groups in development of constrictive pericarditis/pericardial thickening (group A: n = 3, 21.4% and group B: n = 2, 29.6%, p = NS). On multivariate analysis, development of constrictive pericarditis/pericardial thickening was associated with recurrent tamponade (p = 0.01), presence of tamponade at admission (p = 0.07) and haemorrhagic pericardial effusion (p = 0.08). Thus, antitubercular treatment does not prevent the development of constrictive pericarditis in patients of large chronic pericardial effusion of undetermined etiology.