Abstract 3633: N-terminal Pro Brain Natriuretic Peptide is More Useful than Electrocardiograms for Detecting Left Ventricular Hypertrophy in Asymptomatic Patients with Type 2 Diabetes Mellitus from Primary Care
Background: Left ventricular hypertrophy (LVH), an important predictor of cardiovascular disease, is common in patients with type 2 diabetes mellitus (T2DM). Currently there is no routine screening for heart disease, including LVH, in asymptomatic patients with T2DM. The electrocardiogram (ECG) has a low sensitivity for detecting LVH and echocardiography is costly and inaccessible for primary care screening. N-terminal pro brain natriuretic peptide (NT-proBNP) may be increased in patients with LVH.
Objective: To determine whether NT-proBNP was superior to 12-lead ECG for detection of LVH in asymptomatic primary care patients with T2DM.
Methods: Patients with T2DM diagnosed for >5 years and/or on treatment for T2DM were recruited from primary care. Exclusion criteria included: renal dysfunction (GFR<60mL/min) or overt clinical cardiac, cerebrovascular or peripheral vascular disease. Patients underwent comprehensive evaluation including clinical cardiovascular assessment, 12-lead ECG, NT-proBNP measurement (Roche Diagnostics Elecsys assay) and 2D echocardiograms. Either Sokolow-Lyon or Cornell voltage criteria were used. Left ventricular mass was assessed from m-mode or 2D images according to American Society of Echocardiography guidelines (LVH: >45g/m2.7 in women and >49g/m2.7 in men). Receiver operator characteristic curve analysis was carried out and an area under the curve (AUC) was calculated.
Results: 294 patients (149 men) were included. Mean age 58 years (SD 11), body mass index 31.9 kg/m2 (SD 7.0), BP 134/81 mmHg (SD 18/11), HbA1c 7.3% (SD 1.5) and median NT-proBNP 6pmol/L (range <0.6 –175). LVH was diagnosed in 164 patients (56%). In a stepwise multiple regression model age, gender, NT-proBNP were important determinants of left ventricular mass (p<0.05). Only 5 patients with LVH were detected by either ECG voltage criteria. The AUC for NT-proBNP in detecting LVH was 0.68.
Conclusion: LVH was highly prevalent in asymptomatic patients with T2DM. ECG was an inadequate test to identify LVH in this cohort of patients. NT-proBNP was superior to ECG at detecting LVH in patients with T2DM. Given its accessibility, low cost and high patient acceptability, NT-proBNP shows some promise as a potential screening tool for LVH in these patients.