Prognostic Importance of Persistent Elevations in High-Sensitivity Troponin T in the Early Convalescent Phase (two Weeks) Following High-Risk Myocardial Infarction: Insights from the PARADISE-MI Trial

Abstract Introduction Myocardial infarction (MI) is defined by a rise and fall in cardiac troponin (cTn) with clinical evidence of acute myocardial ischemia. How often cTn remains elevated in high-risk patients stabilized following MI and the relation between convalescent cTn levels and subsequent clinical outcomes in these patients is unknown. Aims To evaluate the prognostic importance of high-sensitivity cTn T (hs-cTnT) in the early convalescent phase of a MI for a range of cardiovascular (CV) outcomes in patients enrolled in the Prospective ARNI vs ACE inhibitor trial to DetermIne Superiority in reducing heart failure Events after Myocardial Infarction (PARADISE-MI). Methods Patients ≥18 years without prior heart failure (HF) (n=5661) were randomized to sacubitril/valsartan or ramipril within 0.5 to 7 days of MI complicated by transient pulmonary congestion, LVEF ≤40%, or both. Hs-cTnT was measured using the Roche Elecsys Troponin T-high-sensitive assay in 1093 patients two weeks after randomization (median 2.6 weeks after the index MI). Associations between log (2)-transformed hs-cTnT and clinical outcomes were investigated in landmark analyses using Cox regression models adjusted for clinical covariates of known prognostic importance and NT-proBNP (Figure). Results Median week 2 hs-cTnT concentration was 34 ng/L [IQR 17-94 ng/L] and exceeded the 99th percentile upper reference limit in 69% of patients. Patients with persistently elevated hs-cTnT concentrations (n=753) were older, more likely men, more commonly had atrial fibrillation and lower estimated glomerular filtration rate and less likely had a prior MI. They more commonly had presented with ST-segment elevation MI and pulmonary congestion and had higher concentrations of NT-proBNP. Rates of primary reperfusion were similar. Log(2)-transformed hs-cTnT was only weakly correlated with LVEF (rho = -0.15, p<0.001), irrespective of the type of MI. hs-cTnT was independently and linearly associated with the primary composite outcome of CV death or incident HF (adj HR 1.17 per doubling; 95% CI, 1.03 – 1.34), all-cause death (adj HR 1.20; 95% CI, 1.01 – 1.44) and CV death (adj HR 1.25; 95% CI, 1.02 – 1.52) but not with non-CV death (adj HR 1.04; 95% CI, 0.70-1.54). hs-cTnT was not significantly associated with recurrent fatal or non-fatal MI (adj HR 1.00; 95% CI, 0.85-1.18) (Figure). Concentrations of week 2 hs-cTnT were not altered by sacubitril/valsartan relative to ramipril (+4%; 95% CI, -8% to 18%). Conclusions Persistent elevations in hs-cTnT during the early convalescent phase following high-risk MI are common and are associated with heightened risk of all-cause death, CV death and incident HF but not of recurrent MI or non-CV death. hs-cTnT measured ~2.5 weeks after high-risk MI provides incremental prognostic information beyond traditional risk factors and NT-proBNP.