Jaffe, Allan S.

Background— There is controversy about the diagnostic and prognostic significance of percutaneous coronary intervention–related myocardial infarction, especially with the use of cardiac troponin T (cTnT). This analysis was designed to address the question of the presence and the level of a prognostic cTnT threshold. Methods and Results— We evaluated 5268 consecutive patients who underwent nonemergent percutaneous coronary intervention between 2000 and 2009 with a preprocedural cTnT level below the upper limit of normal (ULN, ≤0.01 ng/mL). Postprocedural cTnT and creatine kinase-MB mass levels (ULN, 6.7 ng/mL in men and 3.8 ng/mL in women) were found to be associated with 3-month mortality in Cox proportional hazard models (hazard ratio per doubling of cTnT, 1.24; 95% confidence interval, 1.08–1.43; P =0.003 and hazard ratio per doubling of creatine kinase-MB, 1.30; 95% confidence interval, 1.05–1.60; P =0.018), adjusted for the Mayo Clinic risk scores for in-hospital and postdischarge mortality. The optimal prognostic threshold for 3-month mortality was 25× ULN for cTnT (hazard ratio, 4.53; 99% confidence interval, 1.59–12.9; P <0.001), which provided similar information as a value of 5× ULN for creatine kinase-MB (hazard ratio, 4.31; 99% confidence interval, 1.27–14.6; P =0.002). The cumulative mortality rate was 0.6% at 91 days. Conclusions— A significant association of postpercutaneous coronary intervention cardiac biomarker elevation with a small number of postpercutaneous coronary intervention outcomes was noted for the early (first 91 days) follow-up period with an identifiable optimal threshold of 25× ULN (0.25, ng/mL) for cTnT, which provided similar early outcome information as a cutoff of 5× ULN for creatine kinase-MB.

Abstract INTRODUCTION High-sensitivity cardiac troponin assays have potent prognostic value in stable cardiovascular disease cohorts. Our objective was to assess the prognostic utility of a novel cardiac troponin I (cTnI) high-sensitivity assay, independently and in combination with amino-terminal pro–B-type natriuretic peptide (NT-proBNP), for the future development of heart failure and mortality in the general community. METHODS A well-characterized community-based cohort of 2042 participants underwent clinical assessment and echocardiographic evaluation. Baseline measurements of cTnI with a high-sensitivity assay and NT-proBNP were obtained in 1843 individuals. Participants were followed for new-onset heart failure and mortality with median (25th, 75th percentile) follow-up of 10.7 (7.9, 11.6) and 12.1 (10.4, 13.0) years, respectively. RESULTS When measured with a high-sensitivity assay, cTnI greater than the sex-specific 80th percentile was independently predictive of heart failure [hazard ratio 2.56 (95% confidence interval 1.88–3.50), P &lt; 0.001] and mortality [1.91(1.49–2.46), P &lt; 0.001] beyond conventional risk factors in this community-based cohort, with significant increases in the net reclassification improvement for heart failure. The prognostic utility of cTnI measured with a high-sensitivity assay goes beyond NT-proBNP, yet our data suggest that these 2 assays are complementary and most beneficial when evaluated together in identifying at-risk individuals in the community. CONCLUSIONS Our findings lay the foundation for prospective studies aimed at identification of individuals at high risk by use of a multimarker approach, followed by aggressive prevention strategies to prevent subsequent heart failure.

Objectives To define whether the high sensitivity cardiac troponin T (hs-cTnT) assay in patients with immunoglobulin light chain amyloidosis (AL) improves risk prediction. Background Cardiac involvement is the major cause of death in patients with AL amyloidosis. Risk stratification is facilitated by cardiac biomarkers such as cardiac troponin T (cTnT) and N-terminal pro B-type natriuretic peptide (NT-proBNP). Methods Stored serum from patients with newly diagnosed AL was used to measure hs-cTnT, cTnT, and NT-proBNP. Survival modelling was performed. Results The direct numeric result from hs-cTnT measurement cannot merely be substituted for a cTnT measurement in the Mayo AL staging system. The performance of the receiver operator curve derived an hs-cTnT cut-point of 54 ng/L which improves on the value of 35 ng/L validated with the prior iteration of the assay. An alternate staging option using hs-cTnT alone—using the two thresholds 14 ng/L and 54 ng/L—performs as well as either the original Mayo AL staging system or other systems incorporating hs-cTnT. On multivariate analysis, an hs-cTnT alone staging system was independent of period of diagnosis, type of therapy, and NT-proBNP value, the last of which dropped out of the model. Alternate models were explored, but none performed better than the original system or the new hs-cTnT system. Thus, hs-cTnT can be used alone for the staging of disease prognosis. Conclusions A survival model based on hs-cTnT improves the prognostic staging of patients with AL amyloidosis, relegating NT-proBNP to a measure of cardiac response.