[Echocardiography-dobutamine test in the short-term evaluation of the results of coronary angioplasty].

BACKGROUND

Coronary angioplasty is commonly performed as a means of coronary revascularization, but at present no method has proven to be of definite value in assessing the functional result of a given angiographic procedure.

OBJECTIVES

The purpose of this study was to evaluate whether dobutamine stress echocardiography can detect a reversal of ischemia-induced left ventricular regional wall motion abnormalities 15 days after an angiographically successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS

25 patients underwent dobutamine stress echocardiography 24-48 hours before and 15 days after an elective angiographically successful PTCA. Twelve out of 25 patients (48%) suffered from a previous myocardial infarction. Symptomatic myocardial ischemia was documented before PTCA in 18/25 patients (72%) and asymptomatic ischemia in 7/25 (28%). Dobutamine was infused utilizing incremental steps of 5 mcg/kg/min over 3 minutes, up to a maximal dose of 40 mcg/kg/min. Echocardiographic images were stored on video tape and analyzed in a qualitative manner by two independent and experienced cardiologists without knowledge of the angiographic data. An asynergy score (from 0 = normal to 3 = dyskinesia) was calculated using a 14-segment left ventricular model in basal conditions and at peak stress, before and after PTCA. All tests were performed taking the patients off the antianginal therapy.

RESULTS

One-vessel coronary artery disease was present in 18/25 (72%) patients, and two-vessel disease in 7/25 (28%) four of these 7 patients underwent PTCA on both involved vessels; mean diameter of the stenosis was 91 +/- 6% before PTCA, and was reduced to 22 +/- 8% after PTCA. Dobutamine stress echocardiography induced wall motion abnormalities in 24/25 patients before and in 4/25 after PTCA; the frequency of dobutamine-induced wall motion abnormalities significantly decreased from 96% to 12% before and after angioplasty (p < .01). All patients developed regional wall motion abnormalities in the region supplied by the dilated vessel. Wall motion score at peak dobutamine infusion improved from 8.5 +/- 4.8 before PTCA to 2.6 +/- 4.9 after PTCA (p < .001). There was a significant increase in the rate-pressure product achieved during the test after PTCA (21300 +/- 400 bts/min.mmHg) compared to the test performed before PTCA (19000 +/- 500 bts/min.mmHg) (p < .05). Dobutamine induced angina in 6/25 patients (24%) and ST-segment changes in 19/25 patients (76%) before PTCA, whereas angina occurred only once after PTCA and ST-segment changes 6 times only after PTCA. No major side effects occurred during dobutamine infusion both before and after PTCA.

CONCLUSIONS

Our study indicates that dobutamine stress echocardiography is a feasible and safe method that accurately demonstrates an early improvement in stress-induced regional left ventricular dysfunction after an angiographically successful coronary angioplasty.