Effect of stress-induced reversible ischemia on serum concentrations of ischemia-modified albumin, natriuretic peptides and placental growth factor

Objective There is controversy whether new biomarkers are able to identify myocardial ischemia in the absence of myonecrosis. Method We measured NT-pro BNP, NT-pro ANP, ischemia-modified albumin (IMA) and placental growth factor (PlGF) in patients undergoing nuclear stress testing for suspected ischemic heart disease. A thallium scan was used for detection of reversible myocardial ischemia and cardiac troponin T (cTnT) for exclusion of stress-induced myonecrosis. Of 195 patients, 24 with reversible and 62 with no perfusion defect were included in the analysis. Plasma levels were measured before, 18 min and 4 h after stress testing. Results Of the 86 patients, 52 received an exercise stress and 34 dipyridamol. New myonecrosis indicated by cTnT could be excluded in all patients. Plasma levels of NT-pro BNP and NT-pro ANP before testing were significantly higher in patients who later developed reversible perfusion defects (NT-pro BNP 139.00 (58.25/367.01) pg/mL vs 327.45 (120.50/972.85) pg/mL, p < 0.05; NT-pro ANP 732.5 (470.0/ 1220.0) pg/mL vs 1470.0 (694.0/ 1910.0) pg/mL, p < 0.05). Plasma levels of NT-pro BNP, NT-pro ANP and PIGF did not change significantly after stress testing, IMA levels rose significantly after 4 h in patients with and without reversible perfusion defects. Conclusion The elevation of NTpro BNP and NT-pro ANP at baseline may represent the cumulative effect of repeated bouts of myocardial ischemia. A single brief episode of provoced ischemia does not cause a significant increase of the measured biomarkers beside from IMA after exercise stress test potentially indicating skeletal muscle ischemia.