Efficacy and safety of routine aspiration thrombectomy during primary PCI for ST-segment elevation myocardial infarction: A meta-analysis of large randomized controlled trials

Manual Thrombus Aspiration and its Procedural Stroke Risk in Myocardial Infarction

Background

The previous large‐scale randomized controlled trial showed that routine thrombus aspiration (TA) during percutaneous coronary intervention (PCI) was associated with an increased risk of stroke. However, real‐world clinical evidence is still limited.

Methods and Results

We investigated the association between manual TA and stroke risk during primary PCI in the OACIS (Osaka Acute Coronary Insufficiency Study) database (N=12 093). The OACIS is a prospective, multicenter registry of myocardial infarction. The primary end point of the present study is stroke at 7 days. A total of 9147 patients who underwent primary PCI within 24 hours of hospitalization were finally analyzed (TA group, n=4448, versus non‐TA group, n=4699 patients). TA was independently associated with risk of stroke at 7 days (odds ratio [OR], 1.92 [95% CI, 1.19‒3.12]; P=0.008) in the simple logistic regression model, while the multilevel random effects logistic regression model with hospital treated as a random effect showed that manual TA was not associated with incremental risk of stroke at 7 days (OR, 0.91 [95% CI, 0.71‒1.16]; P=0.435). The 7‐day stroke risk of manual TA was significantly heterogeneous in different institutions (P_{for interaction}=0.007).

Conclusions

Manual TA during primary PCI for patients with acute myocardial infarction was independently associated with the overall increased risk of periprocedural stroke. However, this result was substantially skewed because of institution specific risk variation, suggesting that the periprocedural stroke may be preventable by prudent PCI procedure or appropriate periprocedural management.

Registration

URL: https://upload.umin.ac.jp/cgi‐open‐bin/ctr_e/ctr_view.cgi?recptno=R000005464. Unique identifier: UMIN000004575.

Rationale and design of a prospective, observational study for the QUantitative EStimation of Thrombus burden in patients with ST-Elevation Myocardial Infarction using micro-computed tomography: the QUEST-STEMI trial

Background

Although the presence of thrombus in patients with ST-elevation myocardial infarction (STEMI) has been linked to adverse outcomes, routine thrombus aspiration has not been proven effective. A potential explanation is that these patients should be risk-stratified. Traditional clinical, laboratory and angiographic parameters used in clinical trials have been proven inadequate to classify patients. Aspirated thrombotic material characteristics might be an additional important parameter that has not yet been addressed. In this report, we aim to describe a methodological analysis of thrombus aspirated from coronary arteries during primary PCI using micro-Computed Τomography (micro-CT). These data will be combined with traditional factors to develop a risk-stratification system with high discriminative power for these patients.

Methods

Eighty-seven patients with STEMI undergoing thrombus aspiration in AHEPA University Hospital, Greece, will be enrolled in the study. The first patient was enrolled in June 2018. After being aspirated, thrombi are preserved in formalin and their volume and density are calculated with micro-CT. Micro-CT allows us to create 3D models of thrombi from a series of x-ray projection images. These models are further analyzed to find the volume and density of extracted thrombi and to assess potential differences in their structure. Association of these variables with clinical parameters and angiographic outcomes will be explored.

Discussion

QUEST-STEMI is-to our knowledge-the first study of volumetric coronary thrombus assessment by micro-CT. This method could be used in larger, clinically-oriented trials to help stratify patients with thrombus burden according to their risk for adverse outcomes.

Trial registration

QUEST-STEMI trial ClinicalTrials.gov number: NCT03429608 Date of registration: February 12, 2018. The study was prospectively registered (registered prior to enrollment of the first participant).

Results of PCI with Drug-Eluting Stents in an All-Comer Population Depending on Vessel Diameter

Long-term outcome after percutaneous coronary intervention (PCI) depends on vessel diameter; however, there is insufficient evidence on particular drug-eluting stent (DES) types in this setting. The aim of the study was to assess long-term performance of PCI depending on stented vessel size and DES generations. This observational study from a prospective Registry of PCI with DES assessed safety (stent thrombosis) and efficacy (major adverse cardiac and cerebrovascular event (MACCE)) of the implantation of first- (DES1) or second-generation DESs (DES2) in small and large vessels. Of 699 patients included in the analysis, 337 (48%) patients underwent PCI in small vessels. PCI in small vessels, especially the left anterior descending artery (LAD) (hazard ratio (HR) 2.6, 95% confidence interval (CI) 1.5-4.5), was associated with a higher rate of MACCEs than that in large vessels (20% vs. 14%, p = 0.025) with no difference in the rate of stent thrombosis (ST). No significant difference in safety and efficacy was found between DES1 and DES2 in small vessels. For large vessels, a higher incidence of MACCEs (21% vs. 9.2%, p = 0.002) driven by a higher rate of re-PCI (15% vs. 6%, p = 0.006) and a higher rate of cumulative stent thrombosis (3.5% vs. 0.5%, p = 0.04) was shown for DES1 than DES2. In multivariate analysis, DES1 was a significant risk factor for MACCEs in large, but not in small vessels. The risk of PCI in small vessels, especially LAD, remains high independent of the type of DES. In contrast, DES2 as a modifiable variable during PCI of a large lesion might improve long-term prognosis.