Negative predictive value of dipyridamole vs. dobutamine stress echocardiography in the long-term follow-up of patients undergoing major vascular surgery.

INTRODUCTION

Perioperative cardiovascular complications are a significant cause of post-surgical morbidity and mortality in patients undergoing major vascular surgery (MVS). Dobutamine stress echocardiography is the most important method of detecting coronary artery disease in these patients. Although dipyridamole stress echocardiography (SE-DIP) and dobutamine stress echo (SE-DOB) have demonstrated similar negative predictive value (NPV) in the early postoperative period in patients undergoing MVS, there are few data concerning the negative predictive value of SE-DIP in the long-term follow-up of this subgroup of patients.

OBJECTIVE

Our aim was to compare the long-term NPV of these two types of stress echocardiography and to compare it with perioperative NPV, based on the working assumption that they are similar.

PATIENTS AND METHODS

A retrospective study was made of 157 patients based on preoperative evaluations for vascular surgery between February 1997 and February 2000. Clinical history and the results of consecutive stress exams were analyzed. We excluded patients with a positive stress echo and those that performed dobutamine stress echo which was considered inconclusive since they did not reach 85% of the maximum heart rate for their age. Therefore, 110 patients were included, 29 (26.4%) with dobutamine and 81 (73.6%) dipyridamole-atropine. The patients were followed after surgery for a period of 2.2 +/- 1 years. Cardiac events were defined as cardiac death, nonfatal acute myocardial infarction and hospitalization for unstable angina. The cumulative probability of event-free survival was compared.

RESULTS

The patients' mean age was 65 +/- 10 years, and 108 (98.1%) were men. After 2.2 +/- 1 years of follow-up, 7 cardiac events occurred in the group with negative SE-DIP (8.6%) and 3 in patients with negative SE-DOB (10.3%). There were no statistically significant differences between the two groups concerning event-free survival (3.7 +/- 0.2 vs. 3.5 +/- 0.2 years for SE-DIP and SE-DOB respectively; p = 0.91). Negative predictive values for SE for perioperative and long-term cardiac events were 97.3% and 90.9% respectively.

CONCLUSIONS

SE-DIP is a good alternative to SE-DOB in the preoperative evaluation of patients undergoing MVS, with the NPV of SE-DIP being similar to SE-DOB in the perioperative period and in long-term follow-up.