Left ventricular hypertrophy (LVH) is a risk factor for cardiovascular disease. Elevated natriuretic peptides in LVH have spurred interest that biomarkers may play a role in screening programs. Adrenomedullin (ADM) is a 52-amino acid peptide mediating vasorelaxation, natriuresis, and diuresis. The midregional portion of proADM (MRproADM) is secreted stoichiometrically with ADM; hence, it can be used as a surrogate marker of ADM. We compared the diagnostic performance of MRproADM for the detection of LVH with N-terminal pro-Btype natriuretic peptide (NTproBNP). Two hundred fifty-three hypertensive patients were derived from a local screening study. The MRproADM and NTproBNP levels were assayed using immunoluminometric assays. The MRproADM levels were significantly elevated in patients with LVH than those without (mean [SD]: 0.73 [0.25] vs 0.59 [0.18] nmol/L, P b .001). In multivariate analyses, male sex (P b .001) and log MRproADM (P = .003) retained significance for detecting LVH. Receiver operating characteristic curve for MRproADM yielded an area under the curve of 0.71; confidence interval, 0.62-0.81; P b .001, superior to NTproBNP. An optimal cutoff value for RproADM as an indicator of LVH was 0.50 nmol/L, with a sensitivity, specificity, and negative redictive value of 90.5%, 36.5%, and 95.1%, respectively. The high negative predictive value of the MRproADM assay allows it to be used as a rule-out test for LVH when stratifying patients into high or low risk. Patients who test positive would necessitate echocardiography, enabling better resource allocation. ; Metadata. Full text of this item is not currently available on the LRA.