Increased levels of cardiac troponin-T in outpatients with heart failure and preserved systolic function are related to adverse clinical findings and outcome.
BACKGROUND
The implications of increased levels of cardiac troponin T in congestive heart failure with preserved systolic function have been poorly evaluated. We hypothesized that its presence might be related to disease severity and prognosis in this setting.


METHODS
Clinical, echocardiographic, 6-min walking test and laboratory data were prospectively obtained in 69 congestive heart failure outpatients with ejection fraction > or = 40%. Serial blood samples were assayed for cardiac troponin T with a third-generation immunoassay and values > or = 0.02 ng/ml were considered abnormal.


RESULTS
Abnormal cardiac troponin T levels in at least one sample were found in 27 patients (39%, group 1). These patients were older (71.7 +/- 11 vs. 63 +/- 12.4 years, P = 0.002); more frequently hospitalized during the previous year (63 vs. 26.2%, P = 0.003), had lower systolic blood pressure (129.3 +/- 19.6 vs. 140.4 +/- 23.5 mmHg, P = 0.04), but had similar proportion of ischemic etiology (55.6 vs. 42.9%, P = 0.21) than those with normal cardiac troponin T (group 2). In groups 1 and 2, the functional class was 2.8 +/- 0.8 and 2.1 +/- 0.9 (P = 0.03), and the distance covered in 6 min was 339 +/- 100 and 386 +/- 103 m (P = 0.05), respectively. In groups 1 and 2, the 18-month congestive heart failure hospitalization-free survival was 22 and 87%, respectively (log-rank test P = 0.0003). In a Cox-proportional hazard model, functional class III-IV (hazard ratio = 5.21, 95% confidence interval: 1.43-18.96) and myocardial injury (hazard ratio = 5.51, confidence interval: 1.58-19.24) were independently associated with prognosis.


CONCLUSIONS
Increased levels of cardiac troponin T were detected in one out of three congestive heart failure outpatients with preserved systolic function and correlated with clinical measures of disease severity and poor outcome. These findings suggest a link between ongoing myocardial injury and progressive impairment in congestive heart failure despite preserved systolic function.
Macin
Stella M
SM
Heart Failure Clinic, Instituto de Cardiologia J.F. Cabral, Corrientes, Argentina. stellam@gigared.com
Perna
Eduardo R
ER
Cimbaro Canella
Juan P
JP
Augier
Natalia
N
Riera Stival
Jorge L
JL
Cialzeta
Jorge
J
Pitzus
Ariel E
AE
Obregon
Ricardo
R
Garcia
Edgar
E
Medina
Fernanda
F
Badaracco
Reynaldo J
RJ
D000368:Aged; D015415:Biomarkers / Q000097:blood; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D010045:Outpatients; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D013599:Systole; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D020107:Troponin T