Objectives Previous studies have reported that low final thrombolysis in myocardial infarction (TIMI) flow and/or myocardial blush grade (MBG) are independent predictors of mortality in patients with ST-elevation myocardial infarction (STEMI). Several studies with thrombus aspiration (TA) showed different results, mainly due to use of TA as an additional device not instead of balloon predilatation (BP). The aim of the present study was to assess impact of TA followed by direct stenting during primary percutaneous coronary intervention (PPCI).
Methods Between Dec 2008 and Jun 2011, a total of 429 patients (107 patients in TA group and 322 patients in BP group) who were eligible for the observation criteria, admitted with STEMI (within 9 h from symptoms onset) and candidates for PPCI were enrolled. Exclusion criteria were a previous PCI on infarct-related artery, infarct-related artery < 2.5 mm in diameter, previous coronary artery bypass graft, cardiogenic shock, 3-vessel disease, left main disease, infarct-related lesion treated with balloon predilatation and TA simultaneously, and calcium or tortuous infarct-related lesion. The main indexes of this study were the TIMI flow grade, MBG, and the rate of 60-min ST-segment resolution > 50% after PCI and in-hospital major adverse cardiac events (MACE). Secondary indexes included distal embolizations of infarct-related artery, peak CK-MB release, and MACE after one year.
Results Baseline clinical and angiographic characteristics, initial TIMI flow and initial MBG did not differ between the two groups. Procedural success was obtained in all patients. Stent length, number of stents per patient, and stent/vessel ratio were similar between both groups. The rate of 60-min ST-segment resolution > 50% was significantly more frequent in TA group than in BP group (69.2% vs 48.5%, P < 0.01). The TIMI flow grade after PCI was significantly higher among patients in TA group compared with BP group (2.65 ± 0.49 vs 2.44 ± 0.61, P < 0.01). Also the MBG was significantly higher among patients in TA group compared with BP group (2.86 ± 0.34 vs 2.41 ± 0.56, P < 0.01). There were 23 patients with evident distal embolizations in the group without TA and two patients in the group with TA (1.9% vs 7.1%, P < 0.05). The peak CK-MB release was significantly lower in TA group compared with the BP group (660 ± 144 U/L vs 711 ± 165 U/L, P < 0.01). There was no difference in between the groups in in-hospital MACE (0.9% vs 2.8%, P > 0.05), in 12-month cardiac mortality (1.2% vs 2.2%, P > 0.05), reinfarction rate (0.9% vs 3.1%,P > 0.05) and target vessel revascularisation (2.8 vs 6.5%, P > 0.05). But Total MACE was significantly higher in BP group compared with the TA group (6.5% vs 14.5%, P < 0.05).
Conclusions Compared with conventional PCI, TA and direct stenting before primary PCI improved final myocardial reperfusion and the long-term outcome for STEMI patients.