IMPAIRED SYSTOLIC BLOOD-PRESSURE RESPONSE TO DOBUTAMINE STRESS-TESTING - A MARKER OF MORE SEVERE FUNCTIONAL ABNORMALITIES IN PATIENTS WITH MYOCARDIAL-INFARCTION

Dobutamine-induced hypotension has been disregarded as a marker of mor e severe functional abnormalities in patients with suspected coronary artery disease. However, its functional significance in patients with myocardial infarction has not been studied. The aim of this study was to define the predictors of systolic blood pressure (SBP) response to dobutamine in patients with previous myocardial infarction. Dobutamine stress (up to 40 mu g/kg per minute) echocardiography was performed i n 326 patients with prior myocardial infarction referred for evaluatio n of myocardial ischemia. A 16-segment, four-grade score model was use d to assess left ventricular function. Wall motion score index was der ived by summation of wall motion score divided by 16. SEP and heart ra te increased from rest to peak dobutamine stress (127 +/- 22 vs 134 +/ - 27 mm Hg and 72 +/- 14 vs 122 +/- 24 bpm, p < 0.00001 in both). An i ncrease of SEP greater than or equal to 30 mm Hg occurred in 50 patien ts (15%). By multivariate analysis, independent predictors of failure of SEP increase were higher peak wall motion score index (p < 0.001), higher resting SEP (P < 0.01), and medication with calcium channel blo ckers (p < 0.05). SEP drop greater than or equal to 20 mm Hg occurred in 54 patients (17%). Independent predictors of SEP drop were higher r esting wall motion score index (p < 0.001), higher resting SEP (P < 0. 0001), and older age (P < 0.05). In patients with myocardial infarctio n, left ventricular function and baseline systolic blood pressure are powerful predictors of SEP response to dobutamine stress testing.