Failed Thrombus Aspiration and Reduced Myocardial Perfusion in Patients With STEMI and Large Thrombus Burden

Thrombus aspiration (TA) is used to decrease large thrombus burden (LTB), but it can cause distal embolization.

The aim of this study was to investigate the impact of TA failure on defective myocardial perfusion in patients with ST-segment elevation myocardial infarction (STEMI) and LTB.

In total, 812 consecutive patients with STEMI and LTB (thrombus grade ≥3) were enrolled, who underwent manual TA during the primary percutaneous coronary intervention. TA failure was defined as the absence of thrombus retrieval, presence of prestenting thrombus residue, or distal embolization. The final TIMI flow grades and other myocardial perfusion parameters of the failed TA group were matched with those of the successful TA group.

The proportion of final TIMI flow grade 3 was lower (74.6% vs 82.2%; P = 0.011) in the failed TA group (n = 279 [34.4%]) than in the successful TA group (n = 533 [65.6%]). The failed TA group also had lower myocardial blush grade, lower ST-segment resolution, and a higher incidence of microvascular obstruction than the successful TA group. TA failure was independently associated with low final TIMI flow grade (risk ratio: 1.525; 95% CI: 1.048-2.218; P = 0.027). Old age, Killip class ≥III, vessel tortuosity, calcification, and a culprit vessel other than the left anterior descending coronary artery were associated with TA failure.

TA failure is associated with reduced myocardial perfusion in patients with STEMI and LTB. Advanced age, hemodynamic instability, hostile coronary anatomy such as tortuosity or calcification, and non-left anterior descending coronary artery status might attenuate TA performance. (Gangwon PCI Prospective Registry [GWPCI]; NCT02038127).