Elevated baseline hs-cTnT levels predict exercise-induced myocardial ischemia in patients with peripheral arterial disease.
BACKGROUND
Due to the systemic nature of atherosclerosis, the prevalence of coronary artery disease (CAD) is high in patients with peripheral arterial disease (PAD). A biochemical assay for assessing cardiac risk might improve clinical evaluation of PAD patients. The aim of this study was to investigate whether a new high-sensitivity cardiac Troponin T (hs-cTnT) assay can predict exercise-induced myocardial ischemia in PAD patients without clinical signs of CAD.


METHODS
Sixty-eight ambulatory patients with Fontaine stage II PAD underwent treadmill stress testing to maximum walking distance. Myocardial ischemia was assessed using a 2-lead Holter ECG and ST-segment depression of ≥ 0.2 mV was considered significant. Hs-cTnT was measured from serum samples taken at baseline as well as 5, 10 and 30 min after exercise.


RESULTS
Hs-cTnT baseline levels were significantly higher (19.3 ng/L (5.0; 20.2 ng/L) vs. 6.6 ng/L (4.4; 9.4 ng/L); p=0.037) and increase of serum levels 5 min after cessation of exercise was more pronounced (1.09 ng/L (0.23; 1.80 ng/L) vs. 0.22 ng/L (-0.1; 0.65 ng/L), p=0.032) in ECG positive patients compared to individuals with normal ECG. Logistic regression analysis identified the baseline hs-cTnT serum level as an independent risk factor for developing significant exercise-induced ST-segment depression (odds ratio 1.2 per 1-unit increase, p=0.015).


CONCLUSIONS
In patients with PAD, exercise-induced myocardial ischemia is associated with elevated baseline levels and a significant early increase of hs-cTnT serum levels.
Department of Vascular Surgery, Department of Vascular Surgery, Wilhelminenhospital Vienna, Montleartstrasse 37, 1171 Vienna, Austria. Juergen.Falkensammer@alumni.mayo.edu
Jürgen
J
Falkensammer
Simon
S
Gasteiger
Tatjana
T
Stojakovic
Markus
M
Stühlinger
Hubert
H
Scharnagl
Andreas
A
Frech
Gustav
G
Fraedrich
Andreas
A
Greiner
Kurt
K
Huber
D000368:Aged; D015415:Biomarkers / Q000097:blood; D004562:Electrocardiography; D015444:Exercise; D005080:Exercise Test; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D058729:Peripheral Arterial Disease / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D020107:Troponin T