title: Association of cardiac troponin I with disease severity and outcomes in patients with pulmonary hypertension.
abstract: Previous studies have identified cardiac troponin I (cTnI) as an important marker in pulmonary hypertension (PH) prognosis. However, traditional assays are limited by poor sensitivity, even among patients at high risk. cTnI was measured in 255 PH patients using a new highly sensitive (hs) assay. Other measures included demographics, creatinine, 6-minute walk distance, hemodynamics, cardiac magnetic resonance imaging, and B-type natriuretic peptide level. The association between cTnI and survival was assessed using Kaplan-Meier analysis and Cox regression. cTnI was detectable with the hs assay in 95% of the patients with a median level of 6.9 pg/ml (IQR 2.7-12.6 pg/ml). Higher cTnI levels associated with higher levels of B-type natriuretic peptide, shorter 6-minute walk distance, and more severe hemodynamic and cardiac magnetic resonance imaging abnormalities. During a median follow-up of 3.5 years, 60 individuals died. Unadjusted event rates increased across higher cTnI quartiles (3, 5, 13, 17 events/100 person-years, respectively, p trend = 0.002). cTnI in the fourth (vs first) quartile remained associated with death in a final stepwise multivariable model that included clinical variables and hemodynamics (adjusted hazard ratio 5.3, 95% confidence interval 1.8-15.6). In conclusion, cTnI levels, detectable with a novel hs assay, identify patients with PH who have more severe hemodynamic and cardiac structural abnormalities and provide novel and independent prognostic information. This hs assay has the potential to detect more at-risk patients and improve current risk-stratification algorithms.
authors.affiliation: Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA. mariella.velez-martinez@phhs.org
authors.forename: Mariella
authors.initials: M
authors.lastname: Vélez-Martínez
authors.forename: Colby
authors.initials: C
authors.lastname: Ayers
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Mishkin
authors.forename: Sonja B
authors.initials: SB
authors.lastname: Bartolome
authors.forename: Christine K
authors.initials: CK
authors.lastname: García
authors.forename: Fernando
authors.initials: F
authors.lastname: Torres
authors.forename: Mark H
authors.initials: MH
authors.lastname: Drazner
authors.forename: James A
authors.initials: JA
authors.lastname: de Lemos
authors.forename: Aslan T
authors.initials: AT
authors.lastname: Turer
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Chin
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I