To investigate the effect and significance of ischemic postconditioning methods on serum nerve growth factor (NGF) and myocardial infarction area in patients with acute myocardial infarction (AMI).

From January 2016 to December 2019, 200 cases with AMI within 12 hours in Cardiology Department of Jilin Central Hospital were selected, and percutaneous coronary intervention (PCI) treatment was performed in the Emergency Department. They were randomly divided into ischemic postconditioning group (n=100) and control group (n=100) by random number table method. The ischemic postconditioning group used balloon pre-expansion and repeated filling and re-inhalation to achieve reperfusion ischemia treatment of infarct-related arteries, while the control group was given conventional PCI. The serum markers of myocardial injury levels, NGF levels and myocardial infarction areas were compared between the two groups.

At admission, the serum levels of creatine kinase isoenzyme (CK-MB), cardiac troponin I (cTnI) and NGF of ischemic postconditioning group were (96.55±4.68)U/L, (21.03±2.25)μg/L and (0.13±0.06)ng/L, respectively. Comparing with the control group [(97.38±5.46)U/L, (21.24±2.36)μg/L, (0.12±0.04)ng/L], the differences were not statistically significant (t=1.15, 0.64, 1.39, all P>0.05). Three days after admission, cTnI level [(22.96±2.46)μg/L] in the ischemic postconditioning group was lower than that in the control group [(39.85±3.68)μg/L], CK-MB [(101.28±3.46)U/L] and serum NGF [ (0.22±0.03)ng/L] levels were higher than those in the control group [ (93.50±5.68)U/L, (0.14±0.06)ng/L], the differences were statistically significant (t=38.16, 11, 70, 11.93, all P<0.05). Seven days and 14 days after admission, CK-MB [(13.43±2.35)U/L, (4.23±1.38)U/L], cTnI[(6.33±1.38)μg/L, (0.78±0.14)μg/L] and serum NGF [(0.14±0.04)ng/L, (0.12±0.04)ng/L] levels of ischemic postconditioning group were lower than those in the control group [CK-MB (15.48±4.96)U/L, (6.47±1.35)U/L, cTnI (7.75±2.47)μg/L, (1.15±0.39)μg/L, NGF (0.22±0.05)ng/L, (0.19±0.05)ng/L], the differences were statistically significant (t=3.74, 11.60, 5.02, 8.93, 12.49, 10.93, all P<0.05). After 6 months, the number of cases with different myocardial infarction areas between the two groups was statistically significant (χ²=50.08, P<0.05).

Serum NGF level in AMI patients undergoing ischemic postconditioning shows a dynamic change, and the peak of NGF level comes earlier, which can be used as an indicator of effectivity and prognosis. The ischemic postconditioning can effectively reduce the area of myocardial infarction in patients with AMI.