Dobutamine stress echocardiography after cardiac transplantation: implications of donor–recipient age difference

Dobutamine stress echocardiography (DSE) is widely used during follow-up after cardiac transplant for the diagnosis of allograft vasculopathy. We investigated the effect of donor–recipient age difference on the ability to reach target heart rate (HR) during DSE. All cardiac transplant patients who were undergoing DSE over a 3-year period in a single institution were reviewed. Target HR was specified as 85%×(220 – patient age). Further patient and donor demographics were obtained from the local transplant database. 61 patients (45 male, 55±12 years) were stressed with a median dose of 40 mcg/kg per min dobutamine. Only 37 patients (61%) achieved target HR. Donor hearts were mostly younger (mean 41±14 years, P<0.001), with only 11 patients (18%) having donors who were older than they were. Patients with older donors required higher doses of dobutamine (median 50 vs 30 mcg/kg per min, P<0.001) but achieved a lower percentage target HR (mean 93% vs 101%, P=0.003) than those with younger donors did. Patients with older donors were less likely to achieve target HR (18% vs 67%, P=0.003). In conclusion, donor–recipient age difference affects the likelihood of achieving target HR and should be considered when a patient is consistently unable to achieve ‘adequate’ stress according to the patient's age.