Aim: In this study we sought to determine the safety, feasibility and prognostic value of pharmacological stress echocardiography performed in a primary care cardiology centre, populated by unselected patients evaluated with the aid of limited financial and technological resources.
Methods and results: The study population was 1082 patients undergoing pharmacological stress echocardiography with either dipyridamole (n=714) or dobutamine (n=368) for the evaluation of known or suspected coronary artery disease. The echocardiogram was positive in 284 (26%) patients. Two sustained ventricular tachycardias, reversible by antidote, occurred during stress testing. Limiting ischaemia-independent side effects occurred in 1.5% dipyridamole and in 2.4% dobutamine stress echocardiograms. During follow-up (33+/-18 months), 17 cardiac deaths and 27 non-fatal myocardial infarctions occurred. One hundred and twenty-seven patients underwent coronary revascularization, of whom 105 (37%) had a positive and 22 (3%) a negative stress testing result (P<0.0001). At Cox analysis, allowing for 14 clinical and stress-echo variables. the independent predictors of cardiac death were, in decreasing order, a positive stress testing result (Odds ratio [OR]=6.0), resting wall motion score index (OR=5.7), age greater than 65 years (OR=4.9), previous Q-wave myocardial infarction (OR=3.5), and hypercolesterolaemia (OR=2.7). The 4-year survival rate was 99.2% for patients with a negative and 89.8% for patients with a positive stress testing result (P=0.0000). When cardiac hard events (cardiac death and non-fatal myocardial infarction) were considered as end-points, the following variables were independently associated with prognosis: positive result of stress testing (OR=3.1), hypercolesterolaemia (OR=2.4), and resting wall motion score index (OR=2.7). The 4-year infarction-free survival rate was 97.0% for patients with a negative and 81.4% for patients with a positive stress testing result (P=0.0000).
Conclusions: Pharmacological stress echocardiography with either dipyridamole or dobutamine was safe and feasible, providing an excellent tool for prognostic assessment of coronary artery disease in a primary care cardiology centre.