Abstract 19972: Validation of the Universal Definition of Type 4a Myocardial Infarction with High Sensitivity Troponin T in Patients with Non-ST Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Interventions
Introduction: The current Universal Definition of peri-procedural myocardial infarction (PMI) in patients with NSTEACS is arbitrary and remains unsubstantiated by clinical trials. Its relevance in the era of high sensitivity troponin (hsTn) is also undetermined. Validation of this definition with hsTn would therefore have significant implications both for outcome assessment in scientific trials and clinical practice.
Methods: High sensitivity troponin T (hsTnT; Roche Diagnostics; 99th percentile 14ng/L) was introduced at our institution in March 2011. A review of our prospective cohort between May 2011 and April 2012 was performed and outcome data obtained. Patients with NSTEACS undergoing PCI with normal, stable or declining pre-procedural hsTnT were included for analysis.
Results: Of the 221 patients who underwent PCI for NSTEACS during the study period, one hundred and ninety six patients (88.7%) were eligible for analysis. Among them 71% were male, while the mean age was 68.0(+/-11.6). Forty-one percent had NSTEMI, while the rest had UAP. At angiography, single, double and triple vessel diseases were found in 58.2%, 30.1% and 5.1%, respectively. Procedural success was achieved in 98.9%. PMI occurred in 5.6% of the patients based on the Universal Definition. The only predictor of PMI was female sex (OR 4.7; 95% CI 1.3-16.8, p=0.017). Follow up was available in 94.9% at 12 months. MACE (MI, death and revascularisation) occurred in 6.5%. In a multivariate model, PMI was significantly associated with MACE (OR 6.6, 95% CI 1.2-36.9, p=0.03). This was driven primarily by the need for revascularisation. Neither peri-procedural changes in hsTnT nor clinical signs in isolation were predictive of MACE. The absolute level of post procedural hsTnT was significantly higher in those with MACE (Median 320 v.s. 54 ng/L, p = 0.004), and was a fair predictor of MACE at 12 months (AUC = 0.75).
Conclusions: Post procedural hsTnT as a cumulative measure of spontaneous and PCI related myonecrosis is associated with worse clinical outcome at 12 months in patients with NSTEACS undergoing PCI. In addition, PMI as defined by current Universal Definition using hsTnT is an independent contributor to this risk, and remains a key outcome measure in clinical trials and a target for therapy.
Author Disclosures: K. Liou: None. P. Kellar: None. B. Ng: None. J. Isbister: None. R. Giles: None. N. Jepson: None. D. Friedman: None. R. Allan: None. A. Lau: None. M. Pitney: None. S. Ooi: None.
- © 2014 by American Heart Association, Inc.