The value of negative stress echocardiography in predicting cardiovascular events among adults with no known coronary disease

Introduction: Stress echocardiography is a safe and cost-effective method of evaluating the patients with suspected coronary artery disease (CAD). However, the risk factors of an adverse cardiovascular event after a normal exercise (ESE) or dobutamine (DSE) stress echocardiography are not well established.
Methods: A cohort of 705 patients without previous history of CAD and a negative ESE/DSE was studied. All studies were performed in a high-volume echocardiologic laboratory and interpreted by two experienced echocardiography-trained cardiologists. Patients with inconclusive studies and those with an evidence of myocardial ischemia were excluded. Demographic, echocardiographic and hemodynamic findings were recorded. Patients were followed for at least 2 years. Independent predictors of major adverse cardiovascular events (MACE) were determined by regression analysis.
Results: During a period of 55.7±17.5 months, MACE occurred in 35 (5.0%) of patients. Negative predictive value (NPV) of DSE was 89.2%, which was significantly less than 96.5% for ESE in predicting the occurrence of MACE (P = 0.001). MACE occurred more frequently among older (≥65 years) men with preexisting diabetes, hypertension, and/or hyperlipidemia. During ESE, a higher maximum blood pressure*heart rate product for the achieved level of metabolic equivalent (METS) of tasks was also an independent predictor of MACE.
Conclusion: Inability of patients to undergo traditional ESE that led to the choice of using DSE alternative reduces the NPV of the stress echocardiography among patients without previous history of CAD. A modest rise of heart rate and blood pressure in response to increased level of activity serves as favorable prognostic value and improves the NPV of stress echocardiography.