Clinical Markers Predict Myocardial Infarction and Death in Unstable Angina

pp. 63-71

Abstract

Physicians have attempted to identify clinical markers to dictate practical guidelines for therapeutic decision making in unstable angina (UA).

Objectives
The aim was to assess the prognostic value of clinical markers which identify high risk patients for major in-hospital events (ME) such as myocardial infarction (MI) and/or death .

Methods

1022 patients with UA defined by electrocardiographic (ECG) changes and/or coronary history included in the "Enalapril en la Angina Inestable" trial (ENAI) were analyzed. Baseline clinical markers on and after admission were related to ME. Recurrent angina was based on the presence of symptoms with ECG or hemodynamic disturbance and refractory angina was defined as recurrent angina under maximal medical treatment . Both were defined as recurrent ischemia (RI). The latter was analyzed within the first 48 hours .

Results
Mean age was 62.4 ± 11.5, female 31 .4%, 75% with ECG changes . The prevalence of RI was 22.1%, 14.8% within 48 hours . In 42 patients, a ME was diagnosed (2.8% MI, death 1.6%). Univariate analysis : previous angina (last 24 hours): odds ratio 0.36, 95% CI 0.18-0.70, p 0 .0008; > 2 episodes of angina (last 24 hours): odds ratio 1.85,95% CI 0.94-3.63, p 0.052; no pain relief after nitrites : odds ratio 2.78, 95% CI 1.26-5 .99, p 0.003; history of heart failure : odds ratio 2.67, 95% CI 0.87-7.59, p 0.056; ECG changes (ST changes) : odds ratio 2.59, 95% CI 1.21-5.67, p 0 .007; recurrence of ischemia: odds ratio 3 .78, 95% CI 1.93- 7.41, p 0.000008; recurrence of ischemia (< 48 hours): odds ratio 4.29, 95% CI 2.14-8 .57, p 0 .000004. The absense of previous angina, bad response to nitrites, ECG and RI were predictors of ME in the multivariate analysis .

Conclusions

In UA, baseline clinical markers as well as the characteristic of previous angina and ECG identify a group with higher risk of evolving into MI or death. The lack of response to initial medical treatment and RI within the first 48 hours were the best predictors of unfavorable prognosis .