Short- and long-term prognostic value of cardiac troponin I and dobutamine echocardiography in patients with stabilized acute coronary syndromes

Background: This study investigated the short- and long-term prognostic values of cardiac troponin I (cTnI) and dobutamine echocardiography (DE) in patients with acute coronary syndrome (ACS) who stabilized after medical treatment. Methods and results: 171 consecutive patients of ACS accepted blood sampling for cTnI at the emergency department and DE at 4.9±0.6 days after admission. The prognostic values of cTnI, DE, and combined cTnI and DE were separately investigated at follow up periods of 30 days, 1 year and 3 years for hard events (cardiac death and non-fatal myocardial infarction) and all spontaneous events. CTnI was elevated in 55 (32%) patients and DE was positive in 114 (67%) patients. Elevated cTnI with positive DE were found in 44 (26%) patients. Within 30 days, the combination of elevated cTnI and positive DE provided more accurate prognostic information than each test result alone, and was the only independent predictor for both hard (p=0.014) and all events (p=0.012). After 1 year, cTnI alone had no prognostic value. The combination of an elevated cTnI level and a positive DE only had a prognostic value for all events (p=0.015). However, DE was an independent predictor for both hard (p=0.006) and all events (p=0.002). Neither cTnI alone nor cTnI combined with DE had a significant 3-year prognostic value. However, DE maintained its prognostic value and was still an independent predictor after 3 years for both hard (p=0.024) and all events (p=0.004). Conclusions: For patients with stabilized ACS, the diagnostic finding of elevated cTnI combined with a positive DE has a better short-term prognostic value than each test alone. However, DE alone has a better long-term prognostic value.