Assessment of Time Delay Threshold Values till Primary Percutaneous Coronary Intervention and their Effects on Coronary Artery Flow, Myocardial Perfusion and Left Ventricular Systolic Function

Background: Primary percutaneous coronary artery intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI) leads to myocardial salvage.

Objectives: To test whether shorter periods to primary PCI improve coronary flow, myocardial perfusion and left ventricular systolic function. Methods: 170 patients with acute anterior STEMI treated by primary PCI were evaluated. Time periods from onset of chest pain to first medical contact (FMC) and from FMC to primary PCI (FMC- PCI) and from pain to primary PCI (Pain - PCI) were recorded.

Results: Patients with pain-PCI<300 min, tended to achieve TIMI grade III more frequently (51%vs 33%), p=0.06 and more frequent MBG≥2, (53% vs 36%), p=0.08. Partial ST-elevation resolution was achieved more frequently in patients with pain- PCI<180min (87% vs 65%), p<0.05. Lower peak troponin levels were found in patients with pain- PCI<300 min (49.2±45.2 vs 84.2 ±43 ng/ml), p=0.03. In patients with pain-PCI< 180min, left ventricular ejection fraction (LVEF) increased by 10±8% vs 5.5±5%, p<0.05. In patients with pain-FMC < 90 and < 120 min the increase in LVEF was larger than in others, p<0.05. FMC- PCI less< 180min was associated with larger increase in LVEF, p<0.05.

Conclusion: Decreasing pain to PCI intervals, improves myocardial perfusion and LVEF.

Keywords: STEMI; Primary coronary angioplasty; coronary flow; Left ventricular function.