66 Comparing Conventional and High Sensitivity Troponin in Predicting a Major Acute Coronary Event in Chest Pain Patients with Intact Renal Function

Abstract

This study determined whether high sensitivity troponin outperformed its predecessor in predicting a major adverse coronary event (MACE) in intact kidney function patients. This retrospective cohort study of ED patients diagnosed with chest pain, angina, unstable angina, or myocardial infarction (ICD-10 codes R07, I20, I21) was conducted from January 1 to November 27, 2018 at a tertiary care academic ED center (annual volume 95,000). Inclusion criteria was intact renal function (eGFR > 60 ml/min/1.72m2). The Roche® 4th generation conventional troponin (cTnT) was used until June 12 with a negative troponin defined as <0.06ng/mL and positive as ≥0.06ng/mL. Then, the Roche® 5th generation high sensitivity troponin (hsTnT) was used with a negative troponin defined as ≤14ng/L and a positive as ≥52ng/L. All patients were then reviewed for a MACE, defined as cardiac-related mortality, need for a coronary stent or bypass graft, or clinically diagnosed myocardial infarction type 1 or 2 within 6 weeks of initial ED visit. 6360 ED chest pain patient records were reviewed. 5063 had normal renal function. Of these, 2,655 patients (51±15 years, 56% female) had conventional troponin drawn, of which 147 patients had a MACE (prevalence = 5.5%) (see Table). 53 patients had a positive cTnT, of which 44 patients developed a MACE (PPV = 83.0%). The remaining 2,602 patients had negative cTnT, of which 103 patients developed a MACE (NPV = 96%). The positive likelihood ratio (+LR) of an elevated cTnT detecting a MACE was very high at 83 (95% CI 42, 168). The negative likelihood ratio (-LR) of a negative cTnT excluding a MACE was moderate at 0.70 (95% CI 0.63, 0.78). 2174 patients (49±15 years, 59% female) had a positive or negative high sensitivity troponin, of which 99 patients had a MACE (prevalence = 4.6%). 77 patients had a positive hsTnT of which 51 developed a MACE (PPV = 66.2%). Of the 2097 patients with a negative hsTnT, 48 developed a MACE (NPV = 97.7%). The +LR of a positive hsTnT detecting a MACE was significant at 41 (95% CI 41, 63) but lower than that of cTnT. The -LR of a negative hsTnT excluding a MACE was more significant at 0.49 (95% CI 0.40, 0.60) than that of a negative cTnT. In patients with normal renal function, a negative high sensitivity troponin is more likely than conventional troponin to exclude a MACE event. However, this comes at a slight cost, as a positive high sensitivity troponin has a lesser chance to detect MACE than a positive conventional troponin.Tabled 1Intact Renal ED CP Pts# PtsSensSpecPPV (95% CI)NPV (95% CI)+LR [95% CI]-LR [95% CI]cTnT265529.9%99.6%83.0% (81.5-84.5%)96.0% (95.2-96.8%)83 [42, 168]0.70 [0.63, 0.78]hsTnT217451.5%98.7%66.2% (64.3-68.1%)97.7% (97.1-98.3%)41 [27, 63]0.49 [0.40, 0.60] Open table in a new tab