Regadenoson SPECT MPI post-troponin elevation in two different patient populations: A reliable risk-stratification tool

Excerpt

Elevations in cardiac troponins identify multiple high-risk subgroups of patients including those who present with acute myocardial infarction (MI) without ST-segment elevation and those with unclear etiology for troponin rise. Both of these patient subgroups have an increased risk of mortality. In an 895-patient subset in the invasive arm from the Treat Angina With Aggrastat and Determine Cost of Therapy With Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction (TACTICS-TIMI)-18 trial, patients with positive troponin and ≥ 50% stenosis had the highest rate of 6-month mortality or re-infarction (8.6%) vs 3.1% with a positive troponin but no obstruction and 0% with negative troponin.1 In addition, after an acute MI, the risk of heart failure, cardiac death, and re-hospitalization increases. A similar adverse prognosis is appreciated in those with elevated cardiac troponin of unclear etiology, a population whose prevalence has increased in the era of high-sensitivity cardiac troponin. Lee et al found that 1 in 8 patients without suspected ACS seen in the emergency department who received troponin testing had an elevated concentration. They confirmed prior research showing an association of troponin rise with mortality independent of age, sex, and renal function.2 …