Risk stratification by pharmacological stress echocardiography in a primary care cardiology centre

Abstract

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 myo-cardial 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.