Article Text
Abstract
Objective: To find out whether B-type natriuretic peptide (BNP) detects silent myocardial ischaemia in patients with type 2 diabetes, since many of these patients have silent ischaemia leading to unexpected cardiac deaths.
Design: Prospective cross-sectional study with consecutive recruitment of patients.
Setting: Outpatient, single centre.
Patients: 219 patients with type 2 diabetes. Patients were excluded if they had a history or evidence of cardiac failure.
Outcome measures: BNP, echocardiography and exercise tolerance test (ETT). BNP was compared with the ETT result in all patients and specifically in those who had no apparent ischaemic heart disease (IHD).
Results: 121 patients had no history of IHD or cardiac failure and of these patients 85 had a clearly abnormal or normal ETT result. BNP was higher in patients with an abnormal than with a normal ETT (mean 58.2 (SD 46.3) v 24.4 (SD 15.7) pg/ml, p < 0.001). In univariate analysis BNP was an independent predictor of an abnormal ETT (p < 0.001). In multivariate analysis BNP remained an independent predictor of the ETT result. BNP concentration over 20 pg/ml predicted an abnormal ETT result with a sensitivity of 87% and specificity of 37%, and BNP over 40 pg/ml had a sensitivity of 63% and a specificity of 81%.
Conclusion: BNP is of value in predicting silent ischaemia on exercise testing in asymptomatic patients with type 2 diabetes.
- ACIP, Asymptomatic Cardiac Ischemia Pilot
- BNP, B-type natriuretic peptide
- ETT, exercise tolerance testing
- EUROASPIRE, European action on Secondary Prevention through Intervention to Reduce Events
- IHD, ischaemic heart disease
- IQR, interquartile range
- LV, left ventricular
- LVEF, left ventricular ejection fraction
- LVMI, left ventricular mass index
- natriuretic peptides
- myocardial ischaemia
- exercise tolerance testing