Effect of thrombus aspiration on microcirculatory resistance and ventricular function in patients with high thrombus burden

BACKGROUND: Studies have not demonstrated consistent outcomes following thrombus aspiration in Primary Percutaneous Coronary Intervention (PPCI). We investigated the relationship between thrombus aspiration and microvascular obstruction as measured using Index of Microcirculatory Resistance (IMR) immediately following PPCI and Left Ventricle Function Improvement measured using Global Longitudinal Strain (GLS) six months following PPCI. Our aim is to determine microvascular obstruction and left ventricle function improvement six months following thrombus aspiration during PPCI. METHODS: This was a single-center, observational, prospective non-randomized study involving 45 patients with thrombus score 4-5 (defined as high thrombus burden) and Thrombolysis in Myocardial Infarction (TIMI) flow of 0-2 who subsequently underwent PPCI. Thrombus aspiration was conducted based on physician discretion. The IMR was measured immediately following the procedure. All patients underwent echocardiography to measure GLS at 24 h, 3 months and 6 months following PPCI. RESULTS: Thirty-three (73%) patients underwent thrombus aspiration during PPCI and twelve (27%) patients underwent the conventional PPCI. No significant difference in IMR was found between the group that underwent thrombus aspiration and the group that underwent conventional PCI (51.9 ± 41.5 vs 47.1 ± 35.6 p = 0.723). TIMI flow after PPCI was worse in thrombus aspiration group (OR 5.2 [1.2-23.2], p = 0.041). There was no difference in GLS between two groups at 6-month follow-up (- 13.0 ± 3.4 vs - 12.8 ± 4.6, p = 0.912). CONCLUSION: This study indicates no benefit of thrombus aspiration during PPCI in reducing either microvascular obstruction or left ventricular function at 6-month follow-up for patients with high thrombus burden. Nevertheless, further studies are required before definite conclusions can be made.