Blood pressure and heart rate during an episode of unstable angina as predictors of in-hospital outcome.

PURPOSE: Risk stratification in patients with unstable angina remains a challenging task. Troponins, electrocardiographic changes and clinical characteristics are the most widely employed parameters. Blood pressure and heart rate are proven predictors of short-term outcome; no study, however, has investigated the dynamics of these variables. We postulated that measurements of these parameters performed at the beginning of an ischemic episode would reflect the extent of coronary disease and would predict short-term outcome.

METHODS

Analysis of variance and multivariate logistic regression were used to analyze the relationship of systolic blood pressure and heart rate during ischemic episodes with the occurrence of adverse ischemic events (death, infarction, need for revascularization) prior to hospital discharge.

RESULTS

In a group of 193 patients mortality rate was 4.2%, infarction rate 8.4% and revascularization rate 42.4%. Systolic blood pressure increased during ischemic episodes compared to baseline values in the group of survivors (p < 0.0001), while there were no significant changes in the group of non-survivors. The rise in heart rate during ischemic episodes was greater in non-survivors, even though significant changes were observed in both groups. Systolic pressure and heart rate were independent predictors of mortality (p = 0.01 and p = 0.003, respectively), but were not predictive of infarction or revascularization.

CONCLUSION

Low systolic blood pressure and high heart rate at the beginning of an ischemic episode predict higher in-hospital mortality in patients with unstable angina. Clinical presentation during the ischemic episode should be considered in risk stratification.