Aims: We sought to identify predictors of distal embolization (DE) occurring during primary percutaneous coronary intervention (p-PCI) as well as to assess its impact on both myocardial reperfusion and necrosis, according to time-to-treatment.
Methods and results: Clinical and angiographic characteristics were prospectively assessed in 400 consecutive patients who underwent p-PCI, in order to identify predictors of DE. The impact of DE on Thrombolysis in Myocardial Infarction (TIMI) flow, myocardial blush, and troponin I (TnI) was assessed according to symptom onset-to-balloon time. DE occurred in 64 (16%) patients and did not change with time-to-treatment (P = 0.87). The occlusion pattern of infarct-related artery (IRA), treatment of right coronary artery, higher TIMI thrombus score, longer lesion, and large IRA diameter were predictors of DE. The rate of TIMI 0/1 and myocardial blush 0/1 was higher in patients exhibiting DE when time-to-treatment was < or =6 h (P < 0.0001), while TnI was higher in patients with DE when time-to-treatment was <3 h.
Conclusion: DE during p-PCI occurs more often in the presence of high thrombus burden lesion. It reduces the effectiveness of myocardial reperfusion within 6 h and enhances myocardial damage within 3 h after symptom onset. Afterwards, it does not affect myocardial reperfusion or the extent of myocardial damage.