Abstract 4464: Impact of Thromboaspiration during Primary PCI on Infarcted Segmental Myocardial Function: A Tissue Doppler Imaging Evaluation. EXPIRA Trial Substudy
Background: In the EXPIRA Trial we recently (TCT 2007) observed a MBG 3 and 90’ST resolution achievement in a significantly larger percent of AMI patients treated with manual thrombectomy and stenting compared with standard PCI. TDI quantitatively assess regional myocardial function by measuring systolic strain (SS). We sought to evaluate the impact of thromboaspiration on procedural outcomes and SS by TDI as compared to conventional primary PCI.
Methods: Out of 175 pts from the EXPIRA trial we randomized 75 patients (mean age 66.3±10.6) with Anterior STEMI (≤6 hours from symptoms onset) and an occlusive thrombus at angiography, to Thromboaspiration(Export ®-Medtronic (n=38) (T group)) and standard PCI (n=37) (C group).16 segments model was applied and regional myocardial function was evaluated, ≤ 90’after primary PCI, by measuring peak systolic myocardial strain by TDI. The end-point was the LV function recovery evaluated in terms of global and segmental SS (%) by TDI.
Results: No differences on baseline, clinical and angiographic preprocedural findings were observed between the two groups. After trombectomy a TIMI II flow was present in in 26.3 vs 16.2% (p=ns), TIMI III was 71.5 vs 29.7% (T vs C p= 0.0005). Postprocedural MBG ≥2 was 86.8% vs 59.4% (p=0.009) and 90’ ST-segment resolution was 84.2% vs 40.5% (T vs C, respectively, p= 0.0001).12 pts(16%) were not analyzed because of poor echocardiographic quality. We observed a significative difference (p<0.005) in term of global mean SS between pts treated with thrombectomy (18.1±3.1%) compared with pts treated with standard PCI (15.4±4.2%); considering selectively the infarcted area, the mean SS was 12.2±2.6% in T vs. 8.8±4.3% in C (p< 0.0001).
Conclusions: Compared with conventional stenting, a pretreatment with thrombectomy during primary PCI, improves epicardial flow and procedural outcomes in terms of MBG≥2 and 90’ ST resolution achievement. The difference observed in term of SS between the two groups suggest a rapid and better segmental function recovery in pts treated with Thrombectomy; these data also confirm that SS after primary PCI could be useful to evaluate if primary percutaneus reperfusion has been effective in terms of function recovery.