Primary intervention by stent implantation during acute myocardial infarction is a novel strategy to provide better myocardial perfusion compared to thrombolysis or baloon angioplasty. We aimed to assess the reperfusion achieved by primary stenting, employing TIMI frame count for more objective and quantitative measurement.

Measurements for number of frames required to opacify standardized angiographic landmark branch(TIMI frame count) were determined for the coronary arteries of 77 normal controls and 65 patients with acute myocardial infarction who underwent primary stenting within 12 hours of symptom onset.

In normal subjects, TIMI frame count for left anterior descending artery(LAD) was 1.3 times of mean count of right coronary artery(RCA) and left circumflex artery(LCx), and significant less than that of TIMI study(22.3±4.9 vs 36.2±2.6, p<0.05). TIMI frame count for RCA and LCx was similar to results of TIMI study. In infarct related arteries(IRA), corrected TIMI frame count(CTFC) after primary stenting was similar to those of normal control. Frame counts of RCA was larger compared to that of normal control, but statistically insignificant(23.0±7.5 vs 17.6±3.5, p>0.05). There was no difference of CTFC of non-infarct related arteries between patients and normal controls.

The TIMI frame count of LAD artery in normal Korean subjects was significantly less than that of American counterpart. In patients with acute myocardial infarction, primary stenting appeared to provide improved coronary flow similar to that observed in normal subjects, as measured by TIMI frame counting.