The prognostic value of myocardial perfusion (MP), assessed during stress echocardiography (SE) by myocardial contrast echocardiography (MCE), has been shown in research studies but is untested in a ‘real-world’ clinical SE service.Methods
Patients clinically referred for SE undergoing pharmacological stress, and those doing exercise stress in whom we suspected target heart rate may not be attained, underwent MCE using Sonovue contrast. We documented prospectively patient demographics and SE results by wall motion (WM)and MP. Patients were followed-up for the outcomes of death, myocardial infarction (MI) and late revascularisation.Results
Of 220 patients that underwent MCE during SE, 204(93%) were followed-up. Mean age was 66yrs, 74% were male and 66% had known CAD. Over a mean follow-up period of 16 ± 7 months, there were 35 (17%) events (6 deaths,6 non-fatal MIs and 23 revascularizations). Univariate Cox regression revealed that a history of CAD, inducible ischemia by WM and by MP predicted outcome. On multivariate analysis, inducible ischemia by MP was the strongest predictor of outcome (HR 3.92, p = 0.016) and ischemia by WM did not predict outcome. Kaplan-Meier survival curves showed that patients with abnormal MP (in isolation or combined with WM) had significantly worse outcome than patients with normal MP and WM (Log-rank score 12.6, p = 0.006).Conclusion
Simultaneous MP assessment by MCE, incorporated into a real-world clinical SE service, has incremental prognostic value beyond WM analysis alone.