Background; Acute myocardial infarction is a critical medical illness characterized by an elevated mortality rate. The WHO identifies heart attacks as a predominant cause of mortality globally, with a heightened incidence of serious adverse cardiovascular events in STEMI cases receiving primary percutaneous coronary angiography.

Aims and objectives: to use an easy and noninvasive parameter as assessing pulmonary artery stiffness as a predictor for developing CIN in acute MI patients undergoing primary PCI.

Subjects and methods; This cross-sectional research was performed in the cardiology department of Zagazig University Hospitals commencing in 2024. The present research involved 133 cases with AMI who received primary percutaneous coronary angiography.

Result; A statistically significant difference was found among both groups concerning both after ppci s.creatinine and estimated GFR. Also, negative correlation between post PPCI serum creatinine, and EF by simpson method which was highly statistically significant (p=≤0.001).

Conclusion; pulmonary artery stiffness and PSAP may be an independent indicator for the progress of CIN in acute MI cases participate in primary PCI. The simplicity of PSAP measurement using echocardiography makes it a potentially valuable tool in clinical practice for preventing CIN in acute MI patients undergoing primary PCI.