Combination of quantitative ST deviation and troponin elevation provides independent prognostic and therapeutic information in unstable angina and non-ST-elevation myocardial infarction

Abstract

Background: ST deviation and troponin are indicators of risk in unstable angina/non-ST-elevation myocardial infarction with related but distinct pathophysiology. We hypothesized that a combination of the two would offer complementary information regarding the benefit of an invasive strategy.

Methods and results: Electrocardiogram and troponin data were gathered in 1846 patients in TACTICS-TIMI 18. Adjusting for baseline characteristics, the independent odds ratio (OR) (95% CI) for death or myocardial infarction by 6 months was 1.29 (0.78-2.13) for 0.05 to 0.09 mV ST deviation, 1.83 (1.22-2.75) for > or = 0.10 mV ST deviation, 1.69 (0.96-2.97) for troponin T 0.01 to 0.10 ng/mL, and 2.32 (1.52-3.53) for troponin T > 0.10 ng/mL. There was a significant interaction between the magnitude of ST deviation and treatment strategy (P(interaction) = .04). After adjusting for troponin and other baseline characteristics, an early invasive strategy was associated with a 27% greater reduction in the odds of death or myocardial infarction in those with 0.05 to 0.09 mV of ST deviation (OR(interaction) 0.73, 95% CI 0.27-2.02) and a 64% greater reduction in those with > or = 0.10 mV (OR(interaction) 0.36, 95% CI 0.16-0.84) compared with in those without ST deviation.

Conclusions: The magnitude of ST deviation and degree of troponin elevation are graded independent predictors of outcome in unstable angina/non-ST-elevation myocardial infarction. ST deviation complements troponin elevation in selecting patients for early invasive management.