Detectable serum cardiac troponin T as a marker of poor prognosis among patients with chronic precapillary pulmonary hypertension.
BACKGROUND
Right ventricular failure is a leading cause of death in patients with chronic pulmonary hypertension (PH). We checked whether detection of cardiac troponin T (cTnT), a specific marker of myocyte injury, could be useful in prognostic stratification of those patients.


RESULTS
Initial evaluation of 56 clinically stable patients (age 41+/-15 years) with pulmonary arterial (51 patients) or inoperable chronic thromboembolic (5 patients) PH (mean pulmonary arterial pressure 60+/-18 mm Hg) included cTnT test, allowing detection of its serum levels > or =0.01 ng/mL [cTnT(+)]. cTnT was detectable in 8 of 56 (14%) patients (mean+/-SD, 0.034+/-0.022; range, 0.010 to 0.077 ng/mL). Despite similar pulmonary hemodynamics, they had higher heart rate (92+/-15 versus 76+/-14 bpm, P=0.004), lower mixed venous oxygen saturation (50+/-10% versus 57+/-9%, P=0.04), and higher serum N-terminal pro-B-type natriuretic peptide (4528+/-3170 versus 2054+/-2168 pg/mL, P=0.03) and walked less during the 6-minute walk test (298+/-132 versus 396+/-101 m, P=0.02). Cumulative survival estimated by Kaplan-Meier curves was significantly worse at 24 months in cTnT(+) compared with cTnT(-) (29% versus 81%, respectively, log-rank test P=0.001). Multivariate analysis revealed cTnT status (hazard ratio, 4.89; 95% CI, 1.18 to 20.29; P=0.03), 6-minute walk test (hazard ratio, 0.93 for each 10 m; P=0.01), and pulmonary vascular resistance (hazard ratio, 1.13; P=0.01) as independent markers of mortality. All 3 cTnT(+) patients who survived the follow-up period converted to cTnT(-) during treatment.


CONCLUSIONS
Detectable cTnT is a so-far ignored independent marker of increased mortality risk in patients with chronic precapillary PH, supporting the role of progressive myocyte injury in the vicious circle leading to hemodynamic destabilization.
Torbicki
Adam
A
Department of Chest Medicine, Institute of Tuberculosis and Lung Diseases, Medical University of Warsaw, Poland. torbi@pol.pl
Kurzyna
Marcin
M
Kuca
Paweł
P
Fijałkowska
Anna
A
Sikora
Jarosław
J
Florczyk
Michał
M
Pruszczyk
Piotr
P
Burakowski
Janusz
J
Wawrzyńska
Lilianna
L
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002196:Capillaries / Q000503:physiopathology*; D002908:Chronic Disease; D018450:Disease Progression; D004452:Echocardiography; D017079:Exercise Tolerance; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood* / Q000175:diagnosis* / Q000503:physiopathology; D008168:Lung / Q000098:blood supply*; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D015996:Survival Rate; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D020107:Troponin T