Prognostic Value of the Excercise Test in Unstable Angina

pp 613- 618

Abstract

Background The development of new therapeutical strategies has improved substantially the natural history of unstable angina. But even though this improvement has enabled the evaluation of patients who become a symptomatic through non-invasive tests, the number of studies to evaluate the feasibility and prognostic value of exercise testing in these patients is scarse. Methods The safety and the prognostic value of exercise testing were assessed in 104 patients with unstable angina who responded to medical therapy and were followed-up for 4 months.ResultsTwelve tests were negative, 31 positive, and 61insufficient. A favorable outcome was observed in all patients with maximal negative tests, in 85% of patients with insufficient tests, and in 55% of patients with positive tests (p < 0.005). The sensitivity, specificity and the positive predictive value of exercise testing for an unfavorable outcome(recurrent unstable angina, AMI or death) were61%, 79%, and 45% respectively. Considering insufficient and negative tests together, the negative predictive value of exercise testing was 88%. Inpatients with positive tests, the double product at ischemic threshold and the ischemic threshold workload were significantly lower in those patients with unfavorable outcome: 14794 ± 2942 vs 19718 ± 7533 and 246.6 ± 129 vs 340 ± 132 kg, respectively (p< 0.05). Conclusions Exercise testing after stabilization of patients with unstable angina with intensive medical treatment is a safe and useful procedure which offers a simple risk stratification to assess post-discharge clinical outcome.