PT - JOURNAL ARTICLE AU - Kaspar Broch AU - Arne K Andreassen AU - Einar Hopp AU - Trond P Leren AU - Helge Scott AU - Fredrik Müller AU - Svend Aakhus AU - Lars Gullestad TI - Results of comprehensive diagnostic work-up in ‘idiopathic’ dilated cardiomyopathy AID - 10.1136/openhrt-2015-000271 DP - 2015 Oct 01 TA - Open Heart PG - e000271 VI - 2 IP - 1 4099 - http://openheart.bmj.com/content/2/1/e000271.short 4100 - http://openheart.bmj.com/content/2/1/e000271.full SO - Open Heart2015 Oct 01; 2 AB - Objective Dilated cardiomyopathy (DCM) is characterised by left ventricular dilation and dysfunction not caused by coronary disease, valvular disease or hypertension. Owing to the considerable aetiological and prognostic heterogeneity in DCM, an extensive diagnostic work-up is recommended. We aimed to assess the value of diagnostic testing beyond careful physical examination, blood tests, echocardiography and coronary angiography.Methods From October 2008 to November 2012, we prospectively recruited 102 patients referred to our tertiary care hospital with a diagnosis of ‘idiopathic’ DCM based on patient history, physical examination, routine blood tests, echocardiography and coronary angiography. Extended work-up included cardiac MRI, exercise testing, right-sided catheterisation with biopsies, 24 h ECG and genetic testing.Results In 15 patients (15%), a diagnosis other than ‘idiopathic’ DCM was made based on additional tests. In 10 patients (10%), a possibly disease-causing mutation was detected. 2 patients were found to have non-compaction cardiomyopathy based on MRI findings; 2 patients had systemic inflammatory disease with cardiac involvement; and in 1 patient, cardiac amyloidosis was diagnosed by endomyocardial biopsy. Only in 5 cases did the results of the extended work-up have direct therapeutic consequences.Conclusions In patients with DCM, in whom patient history and routine work-up carry no clues to the aetiology, the diagnostic and therapeutic yield of extensive additional testing is modest.