Background Glucagon-like peptide-1 (GLP-1) is an incretin hormone which has been shown to promote myocardial glucose uptake. Its pharmacological properties as a cardioprotective agent are attractive because it has a short half-life and there is minimal risk of hypoglycaemia.

Objective To assess the hypothesis that intravenous infusion of GLP-1 would protect the heart from ischaemic left ventricular (LV) dysfunction during dobutamine stress echocardiography (DSE) in patients with coronary artery disease (CAD).

Design Randomised crossover study.

Patients and Interventions 14 patients with CAD and good LV function awaiting revascularisation underwent two DSE scans in a randomised order. GLP-1 was infused intravenously at 1.2 pmol/kg/min starting 30 min before the DSE for one of the scans and the other scan acted as a control.

Main outcome measurements Global and regional wall LV function assessed using tissue Doppler imaging at rest, peak stress and 30 min into recovery.

Results Global LV function was greater at peak stress during GLP-1 infusion compared with control (ejection fraction 77.0±4.4 vs 70.8±5.0%, p<0.0001; mitral annular systolic velocity 12.18±3.10 vs 11.31±3.11 cm/s, p=0.0004). GLP-1 infusion improved regional wall LV function in 12 non-apical segments assessed by velocity, strain and strain rate. This beneficial effect was predominantly seen in ischaemic segments. In recovery, infusion of GLP-1 mitigated the post-ischaemic stunning seen in the control scan.

Conclusion Intravenous infusion of GLP-1 protects the heart from ischaemic LV dysfunction induced by dobutamine stress in patients with CAD.

Clinical trial registration URL: http://isrctn.org.

Registration number ISRCTN 69686930.