Coronary artery spasm and dobutamine stress echocardiography in patients without known coronary disease: prevalence, predictors and outcomes

Background and objective Given its high diagnostic and prognostic value and good safety profile, dobutamine stress echocardiography (DSE) is widely used in patients with known or suspected coronary artery disease (CAD); it may however, occasionally induce coronary vasospasm. In this study, we aimed to evaluate the prevalence of dobutamine-related coronary spasm in patients without known CAD, to determine the potential predictors of spasm amongst those with positive DSE and to assess mid-term clinical outcomes.Methods 3,952 patients referred to our echocardiography laboratory for DSE between January 2010 and May 2012 were prospectively investigated. Those with positive DSE underwent coronary angiograms with systematic methylergometrine intracoronary injection in case of absence of significant coronary stenosis or spontaneous occlusive coronary spasm. Patients with spontaneous occlusive coronary spasm or a positive methylergometrine test but no significant stenoses were enrolled and compared with those with positive DSE and significant coronary lesions at angiograms but no history of CAD.Results Twenty-nine patients with DSE-related vasospasm (19.4% of positive DSE without known CAD) were compared with 64 patients with significant coronary lesions. They were significantly younger (56 vs 67.7 years; P < 0.001), had less frequently hypertension (27.6% vs 64.1%; P = 0.01) and diabetes mellitus (31% vs 68.8%; P = 0.01); conversely they had more frequently dyslipidaemia (79.3% vs 53.1%; P = 0.021); they also had a lower ischaemic area at peak DSE (< 4 involved segments) at 79.3% vs 48.4% (P = 0.006). On multivariate analysis, dyslipidaemia (HR = 21.3; 95% CI = [3.45-131.7]; P = 0.001), and less than 4 ischaemic segments at peak DSE (HR = 4.3; 95% CI = [1.14-16.23]; P = 0.034) were found to be independent predictors of coronary spasm rather than significant coronary lesions. Conversely, hypertension, DM and age > 60 were predictors of significant coronary lesions rather than spasm. Long-term actuarial survival free from adverse events was significantly higher in the group of patients with coronary spasm at 93% versus 70% (log rank P = 0.037) in patients with significant coronary disease.Conclusion DSE-induced coronary spasm is an important condition associated with a good mid-term prognosis; dyslipidaemia and lower ischaemic area at peak DSE predicted spasm rather than significant stenoses in patients with positive DSE and no history of CAD.