Interventional Cardiology. Группа авторов

the main reperfusion strategies. Most recent European Society of Cardiology (ESC) guidelines express a preference for primary PCI as the preferred method of reperfusion, with the caveat that it is performed in a timely manner by an experienced team [3]. Similarly American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommend that “primary PCI of the infarct related artery is preferred to fibrinolytic therapy when time‐to‐treatment delays are short and the patient presents to a high‐volume, well‐equipped center with experienced interventional cardiologists and skilled support staff” [4]. A “timely manner” is defined as the performance of primary PCI within 12 h of symptom onset, and within 120 min from STEMI diagnosis [3]. This target is best achieved by regional networks, consisting of a referral PCI center (hub) and non‐PCI centers (spokes), linked by an effective emergency medical system. Such regional networks appear to perform best when covering an area comprising a population of approximately 0.5 million people. Where possible, pre‐hospital diagnosis should be implemented, and patients transferred immediately to the cath lab, bypassing delays associated with initial assessment of patients in the Emergency Department or Cardiac Intensive Care Unit respectively, of up to 20–40 mins in each case [5].

Procedure technique

      Access site selection

      According to current ESC and AHA/ACC guidelines, use of transradial access during primary PCI should be preferred, if performed by an experienced radial operator [3,4]. This is supported by the results of the RIVAL trial [6], which randomized 7021 patients with acute coronary syndrome (ACS) to either radial or femoral access. The hazard ratio for the primary outcome of death, myocardial infarction, stroke or non‐coronary artery bypass graft (CABG) related bleeding at 30 days in the radial group was 0.92 (95% CI 0.72–1.17; p = 0.50) but with a significant interaction with benefit for radial access in the highest volume radial centers (HR 0.49; 95% CI 0.28–0.87; p = 0.015) and specifically, in STEMI (HR 0.60; 95% CI 0.38–0.94; p = 0.026). The RIFLE‐STEACS trial [7], randomized 1001 STEMI patients to either radial or femoral access at four high volume centers, and found that radial access was associated with significantly lower rates of cardiac mortality (5.2% vs 9.2%, p = 0.020) and bleeding (7.8% vs 12.2%, p = 0.026). The MATRIX trial [8], confirmed this finding for a cohort of 8404 ACS patients including 48% STEMI, revealing a rate ratio for Bleeding Academic Research Consortium (BARC) major bleeding unrelated to CABG of 0.67 (95% CI 0.49–0.92; p = 0.013) for radial access, as well as a rate ratio for all‐cause mortality of 0.72 (95% CI 0.53–0.99; p = 0.045).

      Primary PCI strategy

      Primary PCI should be performed immediately following the diagnostic coronary angiogram. Routine use of stenting is recommended.

      Aspiration thrombectomy

Early studies suggested a mortality benefit with aspiration thrombectomy, and it thus found its way into early iterations of the ESC and ACC/AHA STEMI guidelines. The Thrombus Aspiration during Percutaneous Coronary Intervention in Acute Myocardial Infarction (TAPAS) trial randomized 1071 patients in a single center with acute STEMI, prior to diagnostic angiogram, to either thrombus aspiration or conventional PCI, looking at a primary endpoint of myocardial blush grade [9]. A 6Fr Export thrombus aspiration catheter was used for those patients randomized to the thrombus aspiration arm. A myocardial blush grade of 0 or 1 (i.e. absent or minimal myocardial perfusion) was found in 17.1% of the patients in the thrombus‐aspiration group but 26.3% of those in the conventional PCI group (risk ratio 0.65; 95% CI 0.51 to 0.83; p<0.001). Rates of death and major adverse cardiac events at 30 days were significantly related to myocardial blush grade, resolution of ST‐segment elevation, and ST‐segment deviation (p = 0.003 for death and myocardial blush grade, p<0.001 for all other associations). Note that unless contraindicated, abciximab was used in all patients in this study. Subsequent one year follow‐up revealed a hazard ratio of 1.93 (95% CI 1.11–3.37; p = 0.02) for cardiac death in the thrombus aspiration group compared to the conventional PCI group [10].

      However, the Thrombus Aspiration in ST‐Elevation Myocardial Infarction in Scandinavia (TASTE) trial was a randomized, registry‐based clinical trial which enrolled 7244 patients with STEMI to either manual thrombus aspiration followed by PCI, or PCI only, looking at a primary endpoint of all‐cause mortality at 30 days, rather than a surrogate endpoint such as myocardial blush grade [11]. Results revealed no significant difference in mortality (hazard ratio for thrombectomy of 0.94; 95% CI 0.72–1.22; p = 0.63), as well as no significant differences with respect to the rate of stroke or neurological complications at the time of discharge (p = 0.87). Of note, due to the methodology of the trial being registry‐based, there was no additional monitoring and adjudication of the data for the TASTE trial beyond that of the regular Swedish Coronary Angiography and Angioplasty Registry (SCAAR) data validation. Also, for various reasons, only 59.7% of those patients considered for entry into the trial were actually randomized, and there was a large mortality difference between those who underwent randomization and those who did not (2.9% vs 10.6%). Subsequent one year follow‐up showed a hazard ratio for death from any cause of 0.94 (95% CI 0.78–1.15; p = 0.57) for patients in the thrombus aspiration group as compared to the PCI only group [12].

      The Trial of Routine Aspiration Thrombectomy with PCI versus PCI alone in Patients with STEMI (TOTAL) trial attempted to clarify the conflicting results of the TASTE and TAPAS trials [13]. It recruited 10 732 patients at 87 hospitals in 20 countries undergoing primary PCI to a strategy of routine upfront manual thrombectomy with Export catheters versus PCI alone, looking at a primary outcome composed of a composite of death from CV causes, recurrent MI, cardiogenic shock or NYHA class IV heart failure within 180 days. It also included a safety outcome of stroke within 30 days. Overall, there was no significant difference in rates of the primary outcome (hazard ratio in the thrombectomy group 0.99; 95% CI 0.85–1.15; p = 0.86) however the hazard ratio for stroke within 30 days was 2.06 (95% CI 1.13–3.75; p = 0.02).

      A subsequent meta‐analysis of all three trials combined revealed no improvement in clinical outcomes overall [14].

      In terms of mechanical thrombectomy, the AngioJet Rheolytic Thrombectomy In Patients Undergoing Primary Angioplasty for Acute Myocardial Infarction (AIMI) study was a prospective, multicenter trial that randomly assigned 480 acute STEMI patients to treatment with rheolytic thrombectomy (RT) as an adjunct to conventional PCI or PCI alone [15]. All patients were treated with eptifibatide in addition, and it was recommended a temporary pacemaker was be inserted in the RT group. The routine use of RT did not reduce infarct size compared with primary PCI alone. In fact, final infarct size, as assessed by sestamibi imaging, was higher in the RT group compared with PCI alone (p = 0.03).

      A further study evaluated the efficacy of the Rescue Catheter (Boston Scientific), randomizing 215 patients with STEMI to thrombectomy pretreatment or standard PCI. This again showed an increase in infarct size by sestamibi imaging (median 15% vs 8%; p = 0.004) [16].

      The AngioJet Rheolytic Thrombectomy Before Direct Infarct Artery Stenting With Direct Stenting Alone in Patients With Acute Myocardial Infarct (JETSTENT) study [17], again assessed the Angiojet Rheolytic Thrombectomy device, in a multicenter, randomized study that looked at patients with high grade thrombus (TIMI grade 3 to 5) involving 501 patients, looking at both surrogate endpoints (degree of ST elevation resolution) and a composite of major adverse cardiovascular events at 1, 6, and 12 months. ST segment resolution was more frequent in the RT arm (85.8% vs 78.8%; p = 0.043), however no difference was found in other surrogate markers assessed, while at 6 months, there was a MACE event rate of 11.2% in the thrombectomy arm and 19.4% in the direct stenting arm (p = 0.011). This study suggested that in cases of patients with a high thrombus burden, there may be a role for mechanical thrombectomy.

      On this basis of the overall evidence, both the most recent ESC STEMI guidelines, and the 2015 ACC/AHA/SCAI (Society for Cardiovascular Angiography and Intervention) STEMI guideline update, do not recommend routine use of thrombus aspiration [3,18].

      Stent selection

Early studies have shown the benefit of stenting over balloon angioplasty