Prognostic significance of akinesis becoming dyskinesis during dobutamine stress echocardiography.

Background: Akinesis becoming dyskinesis (AKBD) at high-dose dobutamine stress echocardiography (DSE) has been disregarded as a marker of myocardial ischemia. However, its prognostic significance is unknown.

Objectives: We sought to assess the long-term outcome of patients with AKBD during DSE.

Methods: A total of 731 patients (age 62 +/- 15 years, 628 men) with two or more akinetic left ventricular segments at rest underwent DSE and were followed up for a mean period of 5 +/- 2.7 years. The end points considered during follow-up were hard cardiac events (cardiac death and nonfatal myocardial infarction) and heart failure.

Results: Dyskinesis in two or more segments at peak stress developed in 60 patients (8%). Resting wall-motion score index was 2.6 +/- 0.56 in patients with AKBD versus 2.3 +/- 0.55 in patients without AKBD (P = .0002). Ischemia occurred in 197 patients (27%). During follow-up, 254 patients (35%) developed hard cardiac events and 204 patients (28%) developed heart failure. In all, 226 patients (31%) died of various causes (cardiac death in 172 patients). The annualized hard cardiac event rate was 11% in patients with AKBD and 6% in patients without (P = .03). The incidence of heart failure was significantly higher in patients with AKBD than without (47% vs 26%, P < .001). Independent predictors of hard cardiac events were age (hazard ratio [HR] 1.03 [confidence interval {CI} = 1.01-1.04]), previous myocardial infarction (HR 1.4 [CI = 1.1-1.9]), diabetes mellitus (HR 1.8 [CI = 1.3-2.5]), resting wall-motion score index (HR 1.11 [CI = 1.01-1.04]), and AKBD (HR 1.6 [CI = 1.1-2.4]).

Conclusion: AKBD at peak DSE is associated with increased risk of cardiac events in patients with akinetic segments at baseline echocardiogram.