The relationship between serum heart fatty acid binding protein levels and dobutamine stress echocardiography

Background: Heart fatty acid binding protein (HFABP) is a low-molecular weight protein which is abundant in the intracytoplasmic space of myocytes and skeletal muscle. Its serum levels may be expected to increase in myocardial ischemia. The aim of this study was to evaluate the effect of myocardial ischemia induced by dobutamine stres echocardiography (DSE) on serum HFABP levels. Methods: Thirty consecutive patients (mean age 54.9 ± 9.6 years , 53 % male) with stable clinical coronary syndromes, who were ordered a DSE examination for the evaluation of myocardial ischemia made up the study population. Levels of HFABP were measured on venous blood samples obtained immediately before and 1 hour after completion of DSE. The patients were grouped into two as DSE positive (ischemia positive) and DSE negative (ischemia negative). The corresponing basal and 1-hour levels of HFABP were compared between the two groups. The effect of ischemia on HFABP levels were evaluated by comparing the basal and 1-hour levels of HFABP in each group by using within-group statistics. Results: DSE was positive in 8 (27 %) and, negative in 22 (73 %) patients. The clinical characteristics and laboratory findings of the two groups were similar except for a significantly higher age and a significantly more frequent history of myocardial infarction and coronary artery by-pass surgery in the DSE positive group. The basal HFABP levels were similar in the two groups (1.66 ± 1.18 vs. 1.61 ± 0.77, p = 0.884 ). The 1-hour HFABP level was significantly higher in the DSE positive group as compared to the DSE negative group (2.65 ± 1.34 vs.1.85 ± 0.76, p = 0.048). When the basal and 1-hour levels of HFABP were grouped within each group, the 1-hour HFABP rose significantly in the DSE positive group (1.66 ± 1.18 vs. 2.65 ± 1.34, p = 0.004), where it remained unchanged in the DSE negative group (1.61 ± 0.77 vs.1.85 ± 0.76, p = 0.066). Conclusion: Serum HFABP levels rose significantly at 1 hour in the presence of ischemia brought out by DSE in patients with stable clinical coronary syndromes. No such increase was evident in the absence of ischemia.