Direct Stenting after Thrombus Removal before Primary Angioplasty in Acute Myocardial Infarction

Comparison of direct stenting with conventional strategy on myocardial impairments in ST-segment elevation myocardial infarction: a cardiac magnetic resonance imaging study

Direct stenting (DS) without pre-dilatation of the culprit lesion might improve myocardial perfusion and prognosis in patients undergoing percutaneous coronary intervention for ST-elevation myocardial infarction (STEMI); however, some studies report conflicting results. We investigated whether DS provides incremental myocardial benefits over conventional stenting (CS) in STEMI patients based on cardiac magnetic resonance imaging (CMR) measures. Reperfused patients who underwent CMR examinations within 1 week of STEMI onset were selected from a multicenter CMR registry of STEMI (NCT: 03768453). Patients were stratified into either a DS or CS group. Each group comprised 137 patients after 1:1 propensity score matching. Major adverse events (MACEs), including death, myocardial re-infarction, re-admission for heart failure, and stroke were noted during a median period of 44 months (interquartile range 32-58 months). DS was associated with larger (p = 0.007) and shorter (p = 0.005) stent sizes than CS. DS and CS achieved comparable angiographic TIMI-3 flow grades (p = 0.86) and myocardial blush grades (p = 0.70). There were no group differences regarding the incidence of CMR manifestations of microvascular dysfunction, including microvascular obstruction (MVO) (p = 0.89) and intramyocardial hemorrhage (p = 0.47), the extent of MVO (p = 0.21), infarction size (p = 0.83), or left ventricular ejection fraction (p = 0.57). Kaplan-Meier analysis revealed similar risks of MACEs (log rank p = 0.909), which occurred in 23.4% of DS and 26.3% of CS patients (p = 0.576). DS did not show any incremental benefits over CS on myocardial impairments as evaluated using CMR.Clinical Trial Registration: Clinicaltrials.gov, NCT: 03768453.

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.

Impact of direct stenting on myocardial injury assessed by cardiac magnetic resonance imaging and prognosis in ST-elevation myocardial infarction

BACKGROUND

The results of studies investigating the clinical benefit of a direct stenting (DS) strategy in ST-elevation myocardial infarction (STEMI) are inconsistent and data regarding cardiac magnetic resonance (CMR) parameters of myocardial injury are lacking. The aim of this study was to investigate the effect of DS on myocardial damage in comparison to a conventional stenting technique (CS) with predilation in patients with reperfused STEMI.

METHODS

In a subanalysis of the randomized LIPSIA CONDITIONING trial (NCT02158468), STEMI patients were stratified according to the percutaneous coronary intervention technique into the DS (n = 171) or CS (n = 171) group after matching the patients for age (±5 years), gender, and TIMI flow before coronary intervention. Patients underwent CMR imaging within one week after infarction. Clinical outcome (death, reinfarction, hospitalization for heart failure) was assessed within 6 months after the index event.

RESULTS

Patients in the DS group had significantly lower infarct size (16 vs. 19% of left ventricular mass; p = 0.046) and microvascular obstruction with significant improvement of left ventricular parameters, which was associated with favorable clinical outcome with a lower incidence of heart failure hospitalizations (4% vs. 11%, p = 0.011) and mortality (5% vs. 12%, p = 0.034) as compared to patients with CS. In multivariate Cox regression analysis, DS was identified as an independent predictor of reduced mortality (HR 0.30, 95% CI 0.11-0.87, p = 0.026).

CONCLUSION

In patients with acute reperfused STEMI, DS is safe and feasible with a significant reduction of infarct size compared to CS and subsequent lower incidence of heart failure hospitalizations and mortality.

ST-elevation myocardial infarction, thrombus aspiration, and different invasive strategies. A TASTE trial substudy

BACKGROUND

The clinical effect of thrombus aspiration in ST-elevation myocardial infarction may depend on the type of aspiration catheter and stenting technique.

METHODS AND RESULTS

The multicenter, prospective, randomized, open-label trial Thrombus Aspiration in ST-Elevation myocardial infarction in Scandinavia (TASTE) did not demonstrate a clinical benefit of thrombus aspiration compared to percutaneous coronary intervention alone. We assessed the effect of type of aspiration device, stent type, direct stenting, and postdilatation on outcomes at 1 year. There was no difference in all-cause mortality, between the 3 most frequently used aspiration catheters (Eliminate [Terumo] 5.4%, Export [Medtronic] 5.0%, Pronto [Vascular Solutions] 4.5%) in patients randomized to thrombus aspiration. There was no difference in mortality between directly stented patients randomized to thrombus aspiration compared to patients randomized to percutaneous coronary intervention only (risk ratio 1.08, 95% CI 0.70 to 1.67, P=0.73). Similarly, there was no difference in mortality between the 2 randomized groups for patients receiving drug-eluting stents (risk ratio 0.89, 95% CI 0.63 to 1.26, P=0.50) or for those treated with postdilation (risk ratio 0.72, 95% CI 0.49 to 1.07, P=0.11). Furthermore, there was no difference in rehospitalization for myocardial infarction or stent thrombosis between the randomized arms in any of the subgroups.

CONCLUSIONS

In patients with ST-elevation myocardial infarction randomized to thrombus aspiration, the type of aspiration catheter did not affect outcome. Stent type, direct stenting, or postdilation did not affect outcome irrespective of treatment with thrombus aspiration and percutaneous coronary intervention or percutaneous coronary intervention alone.

CLINICAL TRIAL REGISTRATION

URL: ClinicalTrials.gov. Unique identifier: NCT01093404, https://clinicaltrials.gov/ct2/show/NCT01093404.

Comparing Direct Stenting With Conventional Stenting in Patients With Acute Coronary Syndromes

Our aim was to compare direct stenting (DS) with conventional stenting (CS) in patients with acute coronary syndrome (ACS). We searched PubMed, EMBASE, and ISI web of science for eligible studies. Primary end point was major adverse cardiac events (MACEs) in short term. Secondary end points were 1-year mortality and after-procedural no-reflow phenomenon. Twelve trials in 8998 patients were included. The odds ratios (ORs) were pooled using the Mantel-Haenszel fixed effect model. Short-term MACEs were significantly reduced in the DS arm in contrast to the CS (5.00% vs 8.08%, DS vs CS, respectively, OR [95% confidence interval] = 0.61 [0.46-0.80], P = .0004). One-year mortality and after-procedural no-reflow phenomenon were significantly lower in the DS group. No heterogeneity was observed through I2 test ( Phet = .81, .89, and .77 for each end point, respectively). This meta-analysis demonstrated that in selected patients with ACS, DS is not only safe and feasible but also reduces short-term and 1-year mortality as well as the occurrence of after-procedural no-reflow phenomenon.

Synergistic effect of thrombus aspiration and abciximab in primary percutaneous coronary intervention

BACKGROUND

Previous studies failed to assess the individual prognostic role of thrombus aspiration (TA) or abciximab in primary percutaneous coronary intervention (pPCI), due their prevalent combined use.

METHODS AND RESULTS

A total of 644 consecutive ST-segment elevation myocardial infarction patients treated with pPCI were included in this retrospective registry from January 2006 to December 2008. Patients were divided in: (a) Group 1, with conventional pPCI; (b) Group 2, with pPCI and abciximab; (c) Group 3, with pPCI and TA; (d) Group 4, with pPCI and abciximab plus TA. Primary end point was the composite of major adverse cardiovascular events (MACEs, defined as overall mortality, myocardial infarction, target vessel revascularization, and major bleedings) at 1 year. Baseline clinical and angiographic characteristics were not different among the groups, with the exception of a younger age in group 4. The two groups of patients treated with TA (group 3 and 4) received more frequently direct stenting (P < 0.001 vs. group 1 for both), presented higher rate of end-procedural TIMI flow grade 3 (P < 0.001 vs. group 1 for both), and lower rate of no-reflow (P = 0.016 and P < 0.001 vs. group 1, respectively). Patients of group 2 presented a borderline nonsignificant trend toward higher rate of end-procedural TIMI flow grade 3 (P = 0.083 vs. group 1). MACEs at 1 year were 43 (29%) in group 1 versus 25 (22%) in group 2 versus 24 (19%) in group 3 versus 32 (13%) in group 4 (log-rank P = 0.001). At the multivariate Cox regression analysis, combined TA plus abciximab in group 4 [hazard ratio (HR): 0.48, confidence interval (CI) 95% 0.28-0.84, P = 0.01] and a higher left ventricular ejection fraction (HR: 0.97, CI 95% 0.95-0.98, P < 0.001) were significantly associated with lower MACE rate.

CONCLUSIONS

The combination of pharmacologic and mechanic antithrombotic treatment during pPCI was associated with better 1-year clinical outcome.

[Thrombectomy in the acute myocardial infarction: A success in the fight against incomplete myocardial perfusion]

Currently, the preferred treatment of persistent ST-segment elevation acute myocardial infarction is primary angioplasty. After successful primary angioplasty, up to 30% of patients develop left ventricular dilation and heart failure, as a result of incomplete microvascular reperfusion. The pathophysiology of the microvascular dysfunction in the setting of primary angioplasty is complex and not completely known. Distal embolization of necrotic and thrombotic material acts as a mayor factor. No treatment has so far demonstrated proven efficacy in this scenario. However, several prophylactic measures have been identified. Among them, the rheolytic trombectomy offers interesting benefits both in surrogate and clinical outcome variables.

Coronary microembolization: from bedside to bench and back to bedside

Coronary microembolization from the erosion or rupture of a vulnerable atherosclerotic plaque occurs spontaneously in acute coronary syndromes and iatrogenically during percutaneous coronary interventions. Typical consequences of coronary microembolization are microinfarcts with an inflammatory response, contractile dysfunction, and reduced coronary reserve. Apart from transient elevations of creatine kinase and troponin, microemboli can be visualized by intracoronary Doppler and the resulting microinfarcts by late-enhancement nuclear magnetic resonance. Statins, antiplatelet agents, and coronary vasodilators protect against microembolization and microinfarction when started before percutaneous coronary interventions. Distal protection devices can retrieve atherothrombotic debris and prevent its embolization into the microcirculation, but their effect on clinical outcome has been disappointing so far, except for saphenous vein bypass grafts. Devices for aspiration of thrombi and thrombus-derived vasoconstrictor, thrombogenic, and inflammatory substances, however, reduce thrombus burden, improve perfusion, and provide protection in patients with acute myocardial infarction.