Delayed Stenting for ST-Elevation Acute Myocardial Infarction in Daily Practice: A Single-Centre Experience

Advances in the treatment of ST Elevation Myocardial Infarction in the UK

The treatment of acute coronary occlusion with Primary PCI has been a major factor in improving outcomes of patients suffering STEMI in the last 15 years, and is the standard treatment for patients suffering STEMI in the UK.

Treatment is beneficial for patients presenting within 12 hours of the onset of symptoms, with the goal being opening of the occluded artery within 150 min of the call for help.

Opening of the occluded artery is typically completed with a drug-eluting stent followed by administration of antiplatelet medications for 12 months. Procedures are performed using the radial artery which is associated with improved outcomes compared to vascular access via the femoral artery.

Evidence is growing to support full revascularisation including the treatment of severe narrowing in other blood vessels as well as the culprit vessel.

Stenting deferral in primary percutaneous coronary intervention: exploring benefits and suitable interval in heavy thrombus burden

BACKGROUND

Deferred stenting, despite being successful in early studies, showed no benefit in recent trials. However, these trials were testing routine deferral; not in patients with heavy thrombus burden.

RESULTS

This is a prospective, Randomized Clinical Trial that included 150 patients who presented with STEMI, patients were allocated into three equal groups after the coronary angiography ± primary intervention and before stenting of the culprit lesion; group (A) included 50 patients with early deferral of stenting, group (B) included 50 patients with late deferral and group (C) included 50 patients with immediate stenting. No-reflow was significantly higher in group C, while Final TIMI flow grade 3 and MBG grade 3 were significantly higher in group A and B than group C; p = 0.019 and < 0.001 respectively, with no significant difference between groups A and B, only the thrombus resolution in group B was significantly higher than group A; p < 0.001. Finally, 6-months, over-all MACE was significantly higher in group C (34.7% vs. 14.6% and 16.3%, p = 0.029).

CONCLUSIONS

Stent deferral was proved to be better than immediate stenting after recanalization of IRA, in achieving TIMI III flow, reducing risk of 6 months MACE, and restoration of myocardial function in a subset of STEMI patients presenting with large thrombus burden. While, no significant difference was found between both deferral times in final TIMI flow, or clinical outcomes.

Factors Associated with the Prognosis of Patients with Acute Myocardial Infarction and Cardiogenic Shock

BACKGROUND Patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) usually have high mortality. This study aimed to identify factors related to the short-term survival of patients with AMI and CS treated by percutaneous coronary intervention (PCI) under intra-aortic balloon pump (IABP) support. MATERIAL AND METHODS This retrospective study included consecutive patients with AMI and CS treated with PCI under IABP support. Clinical characteristics, including the infarct-related artery, lesion number, aspiration catheter usage, conventional or delayed stenting, and thrombolysis in myocardial infarction (TIMI) flow grade before and after PCI, were collected. Patients were followed up postoperatively for 30 days. Multivariate logistic regression was used to identify factors associated with the 30-day mortality. RESULTS There were marked differences between the nonsurvival group (n=49) and the survival group (n=92) in the no-reflow after surgery (49.0% vs 14.1%, P<0.001), postoperative TIMI grade 3 flow (65.3% vs 91.3%, P<0.001), and delayed stent implantation (18.4% vs 37.0%, P=0.022). Factors associated with 30-day mortality were postoperative TIMI grade 3 flow (odds ratio [OR]: 0.227; 95% confidence interval [CI]: 0.076-0.678; P=0.008), delayed stent implantation (OR: 0.371; 95% CI: 0.139-0.988; P=0.047), and intraoperative no-reflow (OR: 2.737; 95% CI: 1.084-6.911; P=0.033). CONCLUSIONS For patients with AMI complicated by CS treated with emergent PCI under IABP support, prevention of no-reflow during surgery by delayed stent implantation can reduce postoperative 30-day mortality in selected cases.

Deferred Stenting for Heavy Thrombus Burden During Percutaneous Coronary Intervention for ST-Elevation MI

Patients with ST-elevation MI (STEMI) usually have a huge thrombus burden in the infarct-related artery. Stenting may lead to high chances of the slow-flow/no-reflow phenomenon that leads to periprocedural MI and adverse cardiovascular events. Deferred stenting may be beneficial in this situation as the thrombus burden will reduce, mitigating the slow-flow/no-reflow phenomenon. However, routine deferral of stenting in patients with STEMI has not been found to be beneficial, but when the patient is properly selected, deferred stenting has the potential for reducing the final infarct size. The authors report the safety and feasibility of deferred stenting after 5 days of prolonged anticoagulation in a 45-year-old smoker with STEMI who had a large thrombus load shown on an angiogram. They review the registries, trials and meta-analyses on deferred stenting in the literature and analyse the benefits and harms of the strategy. They also propose an algorithm for applying a strategy for deferred stenting in clinical practice based on the available data.

Effectiveness of deferred coronary artery stenting in the prevention of no-reflow in patients with acute ST-segment elevation myocardial infarction

It is known that even in spite of timely revascularization of the infarct-related artery, the myocardium in some patients remains hypoperfused. This condition is known as the no-reflow phenomenon, which is associated with an unfavorable prognosis. The systematic review is devoted to the effectiveness of deferred stenting in noreflow prevention. In patients with severe thrombosis, the two-stage revascularization technique is very promising. It is a primary intervention in the form of aspiration thrombectomy and/or balloon angioplasty followed by stenting after a certain period of time. This interval represents a certain therapeutic space, which allows various drugs to act resulting in reduction of blood clot size and risk of procedure-related distal embolization.

Microcatheter-Facilitated Primary Angioplasty in ST-Segment Elevation Myocardial Infarction

BACKGROUND

Direct stenting is the best method for achieving reperfusion in primary percutaneous coronary intervention (PPCI). We hypothesized that the use of a microcatheter (MC) during PPCI when Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 1 after wire crossing would allow visualization of the downstream artery with an optimal TIMI 3 flow at the end of the procedure.

METHODS

In this pilot study, PPCI patients with TIMI flow ≤ 1 after wire crossing formed the MC group (n = 60); the MC was positioned in the distal part of the culprit artery and a small amount of contrast was injected through it to determine stent size and length to treat the culprit lesion. The MC group was compared with previous consecutive patients treated using standard PPCI (n = 94; similar characteristics except for the rate of previous percutaneous coronary intervention).

RESULTS

In the MC group, downstream arteries were visualized in 98% of cases and direct stenting was achieved in 72% vs 31% (P < 0.0001). Final TIMI 3 flow was similar in both groups (97%). There was less manual thrombectomy (20% vs 63%; P < 0.001) and bailout glycoprotein IIb/IIIa inhibitor use (6.7% vs 29.8%; P < 0.002). The incidence of major adverse events (death, shock, severe arrhythmia) and left ventricular ejection fraction were similar. The peak cardiac enzymes level was significantly lower in the MC group.

CONCLUSIONS

The MC strategy appears feasible and safe. It could allow exploring new strategies on the basis of more systematic direct stenting and prepared reperfusion by injecting drugs through the MC before reperfusion.

Management of ST-elevation myocardial infarction in young patients by limiting implantation of durable intracoronary devices and guided by optical frequency domain imaging: "proof of concept" study

AIMS

The aim of this study was to demonstrate the feasibility and safety of ST-elevation myocardial infarction (STEMI) management in young patients by limiting implantation of durable intracoronary devices (using a bioresorbable stent or medical treatment alone).

METHODS AND RESULTS

Patients <50 years old admitted for STEMI with single-vessel disease received a two-stage management strategy. During a second coronary angiography performed between day 2 and day 7, optical frequency domain imaging (OFDI) guided the decision on therapeutic management, i.e., i) in the case of a stenosis greater than 70% or plaque prolapse, implantation of a BVS; or ii) in the other cases, continuation of medical management alone without stenting. All patients underwent systematic angiographic control with OFDI imaging at six months. Among the 653 patients admitted for STEMI, 124 patients were under 50 years old and 45 patients were included. Early management was performed on average at day 3.9 (day 2 - day 7). Thirty-four (34) patients received BVS implantation and 11 were treated medically. Only one major adverse cardiac event (MACE) had occurred at six months.

CONCLUSIONS

In a selected younger population, the management of STEMI guided by OFDI and based on the concept of limiting implantation of durable intracoronary devices appears to be a feasible and safe therapeutic option.

Role of deferred stenting in patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention: A systematic review and meta-analysis

OBJECTIVES

We conducted a meta-analysis of studies comparing deferred stenting strategy versus the conventional approach with immediate stenting in patients with ST elevation myocardial infarction.

BACKGROUND

Deferring stent after mechanical flow restoration has been proposed as a strategy to reduce the risk of "no reflow" in patients with STEMI undergoing primary percutaneous coronary intervention (pPCI). Conflicting evidence is available currently, especially after the recent publication of three randomized clinical trials.

METHODS

Searches in electronic databases were performed. Comparisons between the two strategies were performed for both hard clinical endpoints (all cause-mortality, cardiovascular mortality, unplanned revascularization, myocardial infarction and readmission for heart failure) and surrogate angiographic endpoints (TIMI flow < 3 and myocardial blush grade (MBG) < 2).

RESULTS

Eight studies (three randomized and five non-randomized) were deemed eligible, accounting for a total of 2101 patients. No difference in terms of hard clinical endpoints was observed between deferred and immediate stenting (OR [95% CI]: 0.79 [0.54-1.15], for all-cause mortality; odds ratio (OR) [95% CI]: 0.79 [0.47-1.31] for cardiovascular mortality; OR [95% CI]: 0.95 [0.64-1.41] for myocardial infarction; OR [95% CI]: 1.37 [0.87-2.16], for unplanned revascularization and OR [95% CI]: 0.50 [0.21-1.17] for readmission for heart failure). Notably, the deferred stenting approach was associated with improved outcome of the surrogate angiographic endpoints (OR [95% CI]: 0.43 [0.18-0.99] of TIMI flow < 3 and OR [95% CI]: 0.25 [0.11-0.57] for MBG < 2.

CONCLUSIONS

A deferred stenting strategy could be a feasible alternative to the conventional approach with immediate stenting in "selected" STEMI patients undergoing pPCI.

Deferred Versus Immediate Stenting in Patients With ST-Segment Elevation Myocardial Infarction: A Systematic Review and Meta-Analysis

Background

A number of studies have evaluated the efficacy of deferred stenting vs immediate stenting in patients with ST‐segment elevation myocardial infarction, but the findings were not consistent across these studies. This meta‐analysis aims to assess optimal treatment strategies in patient with ST‐segment elevation myocardial infarction.

Methods and Results

We searched the PubMed, EMBASE, and the Cochrane Library for studies that assessed deferred vs immediate stenting in patients with ST‐segment elevation myocardial infarction. Nine studies including 1456 patients in randomized controlled trials and 719 patients in observational studies were included in the meta‐analysis. No significant differences were observed in the incidence of no‐ or slow‐reflow between deferred stenting and immediate stenting in randomized controlled trials (odds ratio [OR] 0.51, 95%CI 0.17‐1.53, P=0.23, I²=70%) but not in observational studies (OR 0.13, 95%CI 0.06‐0.31, P<0.0001, I²=0%). Deferred stenting was associated with an increase in long‐term left ventricular ejection fraction (weighted mean difference 1.90%, 95%CI 0.77‐3.03, P=0.001, I²=0%). No significant differences were observed in the rates of major adverse cardiovascular events (OR 0.53, 95%CI 0.27‐1.01, P=0.06 [randomized OR 0.98, 95%CI 0.73‐1.30, P=0.87, I²=0%; nonrandomized OR 0.30, 95%CI 0.15‐0.58, P=0.0004, I²=0%]), major bleeding (OR=0.1.61, 95%CI 0.70‐3.69, P=0.26, I²=0%), death (OR=0.78, 95%CI 0.53‐1.15, P=0.22, I²=0%), MI (OR=0.97, 95%CI 0.34‐2.78, P=0.96, I²=35%) and target vessel revascularization (OR 0.97, 95%CI 0.40‐2.37, P=0.95, I²=24%), between deferred and immediate stenting.

Conclusions

Compared with immediate stenting, a deferred‐stenting strategy did not reduce the occurrence of no‐ or slow‐reflow, death, myocardial infarction, or repeat revascularization compared with immediate stenting in patients with ST‐segment elevation myocardial infarction, but showed an improved left ventricular function in the long term.

Primary angioplasty: Effect of deferred stenting on stent size

BACKGROUND

Primary angioplasty with immediate stenting (IS) is the gold standard for ST-segment elevation myocardial infarction (STEMI). Deferred stenting (DS) has been proposed to limit periprocedural complications, and may influence stent size because of thrombus and spasm alleviation.

AIM

We sought to study the effect of DS on stent size.

METHODS

Over the study period, 258 patients underwent primary angioplasty for STEMI (DS, n=84; IS, n=174). An informative coronary angiogram run - i.e. allowing for proper lesion analysis - was selected and anonymized by an independent operator. Two experienced operators randomly analysed these runs, and proposed stent dimensions after having measured vessel diameter and lesion length by quantitative coronary analysis. The primary objective was the variation in stent size between the two coronary angiograms.

RESULTS

The median delay between the two coronary angiograms was 2 days. Overall, the stent length was shorter (-1.64mm; P=0.030) and its diameter was larger (+0.13mm; P<0.001) during the second coronary angiogram, especially in the right coronary arteries.

CONCLUSIONS

DS led to the implantation of a larger and shorter stent; this is probably because DS allows for more accurate assessment of the residual lesion after relief of spasm and thrombus, and may have clinical consequences in terms of stent thrombosis and restenosis.