Bart J. G. L. de Smet

Thrombus aspiration during primary percutaneous coronary intervention.

BACKGROUND Primary percutaneous coronary intervention (PCI) is effective in opening the infarct-related artery in patients with myocardial infarction with ST-segment elevation. However, the embolization of atherothrombotic debris induces microvascular obstruction and diminishes myocardial reperfusion. METHODS We performed a randomized trial assessing whether manual aspiration was superior to conventional treatment during primary PCI. A total of 1071 patients were randomly assigned to the thrombus-aspiration group or the conventional-PCI group before undergoing coronary angiography. Aspiration was considered to be successful if there was histopathological evidence of atherothrombotic material. We assessed angiographic and electrocardiographic signs of myocardial reperfusion, as well as clinical outcome. The primary end point was a myocardial blush grade of 0 or 1 (defined as absent or minimal myocardial reperfusion, respectively). RESULTS A myocardial blush grade of 0 or 1 occurred in 17.1% of the patients in the thrombus-aspiration group and in 26.3% of those in the conventional-PCI group (P<0.001). Complete resolution of ST-segment elevation occurred in 56.6% and 44.2% of patients, respectively (P<0.001). The benefit did not show heterogeneity among the baseline levels of the prespecified covariates. At 30 days, the rate of death in patients with a myocardial blush grade of 0 or 1, 2, and 3 was 5.2%, 2.9%, and 1.0%, respectively (P=0.003), and the rate of adverse events was 14.1%, 8.8%, and 4.2%, respectively (P<0.001). Histopathological examination confirmed successful aspiration in 72.9% of patients. CONCLUSIONS Thrombus aspiration is applicable in a large majority of patients with myocardial infarction with ST-segment elevation, and it results in better reperfusion and clinical outcomes than conventional PCI, irrespective of clinical and angiographic characteristics at baseline. (Current Controlled Trials number, ISRCTN16716833.)

Use of clopidogrel with or without aspirin in patients taking oral anticoagulant therapy and undergoing percutaneous coronary intervention: an open-label, randomised, controlled trial

BACKGROUND If percutaneous coronary intervention (PCI) is required in patients taking oral anticoagulants, antiplatelet therapy with aspirin and clopidogrel is indicated, but such triple therapy increases the risk of serious bleeding. We investigated the safety and efficacy of clopidogrel alone compared with clopidogrel plus aspirin. METHODS We did an open-label, multicentre, randomised, controlled trial in 15 centres in Belgium and the Netherlands. From November, 2008, to November, 2011, adults receiving oral anticoagulants and undergoing PCI were assigned clopidogrel alone (double therapy) or clopidogrel plus aspirin (triple therapy). The primary outcome was any bleeding episode within 1 year of PCI, assessed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00769938. FINDINGS 573 patients were enrolled and 1-year data were available for 279 (98·2%) patients assigned double therapy and 284 (98·3%) assigned triple therapy. Mean ages were 70·3 (SD 7·0) years and 69·5 (8·0) years, respectively. Bleeding episodes were seen in 54 (19·4%) patients receiving double therapy and in 126 (44·4%) receiving triple therapy (hazard ratio [HR] 0·36, 95% CI 0·26-0·50, p<0·0001). In the double-therapy group, six (2·2%) patients had multiple bleeding events, compared with 34 (12·0%) in the triple-therapy group. 11 (3·9%) patients receiving double therapy required at least one blood transfusion, compared with 27 (9·5%) patients in the triple-therapy group (odds ratio from Kaplan-Meier curve 0·39, 95% CI 0·17-0·84, p=0·011). INTERPRETATION Use of clopiogrel without aspirin was associated with a significant reduction in bleeding complications and no increase in the rate of thrombotic events. FUNDING Antonius Ziekenhuis Foundation, Strect Foundation.

Cardiac death and reinfarction after 1 year in the Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS): a 1-year follow-up study

BACKGROUND Percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction can be complicated by spontaneous or angioplasty-induced embolisation of atherothrombotic material. Distal blockage induces microvascular obstruction and can result in less than optimum reperfusion of viable myocardium. The Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS) found that thrombus aspiration resulted in improved myocardial reperfusion compared with conventional PCI, but whether this benefit improves clinical outcome is unknown. We aimed to investigate whether the early efficacy of thrombus aspiration seen in TAPAS translated into clinical benefit after 1 year. METHODS Patients with ST-elevation myocardial infarction enrolled at the University Medical Centre Groningen were randomly assigned in a 1:1 ratio to either thrombus aspiration or conventional treatment, before undergoing initial coronary angiography. Exclusion criteria were rescue PCI after thrombolysis and known existence of a concomitant disease with life expectancy less than 6 months. Of the 1071 patients enrolled between January, 2005, and December, 2006, vital status at or beyond 1 year after randomisation was available for 1060 (99%). The primary endpoint was cardiac death or non-fatal reinfarction after 1 year, and analysis was by intention to treat. The TAPAS trial is registered with Current Controlled Trials number ISRCTN16716833. FINDINGS Cardiac death at 1 year was 3.6% (19 of 535 patients) in the thrombus aspiration group and 6.7% (36 of 536) in the conventional PCI group (hazard ratio [HR] 1.93; 95% CI 1.11-3.37; p=0.020). 1-year cardiac death or non-fatal reinfarction occurred in 5.6% (30 of 535) of patients in the thrombus aspiration group and 9.9% (53 of 536) of patients in the conventional PCI group (HR 1.81; 95% CI 1.16-2.84; p=0.009). INTERPRETATION Compared with conventional PCI, thrombus aspiration before stenting of the infarcted artery seems to improve the 1-year clinical outcome after PCI for ST-elevation myocardial infarction.

Culprit Vessel Only Versus Multivessel and Staged Percutaneous Coronary Intervention for Multivessel Disease in Patients Presenting With ST-Segment Elevation Myocardial Infarction : A Pairwise and Network Meta-Analysis

OBJECTIVES The purposes of this study were to investigate whether, in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD), percutaneous coronary intervention (PCI) should be confined to the culprit or also nonculprit vessels and, when performing PCI for nonculprit vessels, whether it should take place during primary PCI or staged procedures. BACKGROUND A significant percentage of STEMI patients have MVD. However, the best PCI strategy for nonculprit vessel lesions is unknown. METHODS Pairwise and network meta-analyses were performed on 3 PCI strategies for MVD in STEMI patients: 1) culprit vessel only PCI strategy (culprit PCI), defined as PCI confined to culprit vessel lesions only; 2) multivessel PCI strategy (MV-PCI), defined as PCI of culprit vessel as well as ≥1 nonculprit vessel lesions; and 3) staged PCI strategy (staged PCI), defined as PCI confined to culprit vessel, after which ≥1 nonculprit vessel lesions are treated during staged procedures. Prospective and retrospective studies were included when research subjects were patients with STEMI and MVD undergoing PCI. The primary endpoint was short-term mortality. RESULTS Four prospective and 14 retrospective studies involving 40,280 patients were included. Pairwise meta-analyses demonstrated that staged PCI was associated with lower short- and long-term mortality as compared with culprit PCI and MV-PCI and that MV-PCI was associated with highest mortality rates at both short- and long-term follow-up. In network analyses, staged PCI was also consistently associated with lower mortality. CONCLUSIONS This meta-analysis supports current guidelines discouraging performance of multivessel primary PCI for STEMI. When significant nonculprit vessel lesions are suitable for PCI, they should only be treated during staged procedures.

Clinical ResearchInterventional CardiologyCulprit Vessel Only Versus Multivessel and Staged Percutaneous Coronary Intervention for Multivessel Disease in Patients Presenting With ST-Segment Elevation Myocardial Infarction: A Pairwise and Network Meta-Analysis

OBJECTIVES The purposes of this study were to investigate whether, in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD), percutaneous coronary intervention (PCI) should be confined to the culprit or also nonculprit vessels and, when performing PCI for nonculprit vessels, whether it should take place during primary PCI or staged procedures. BACKGROUND A significant percentage of STEMI patients have MVD. However, the best PCI strategy for nonculprit vessel lesions is unknown. METHODS Pairwise and network meta-analyses were performed on 3 PCI strategies for MVD in STEMI patients: 1) culprit vessel only PCI strategy (culprit PCI), defined as PCI confined to culprit vessel lesions only; 2) multivessel PCI strategy (MV-PCI), defined as PCI of culprit vessel as well as ≥1 nonculprit vessel lesions; and 3) staged PCI strategy (staged PCI), defined as PCI confined to culprit vessel, after which ≥1 nonculprit vessel lesions are treated during staged procedures. Prospective and retrospective studies were included when research subjects were patients with STEMI and MVD undergoing PCI. The primary endpoint was short-term mortality. RESULTS Four prospective and 14 retrospective studies involving 40,280 patients were included. Pairwise meta-analyses demonstrated that staged PCI was associated with lower short- and long-term mortality as compared with culprit PCI and MV-PCI and that MV-PCI was associated with highest mortality rates at both short- and long-term follow-up. In network analyses, staged PCI was also consistently associated with lower mortality. CONCLUSIONS This meta-analysis supports current guidelines discouraging performance of multivessel primary PCI for STEMI. When significant nonculprit vessel lesions are suitable for PCI, they should only be treated during staged procedures.

Metalloproteinase Inhibition Reduces Constrictive Arterial Remodeling After Balloon Angioplasty A Study in the Atherosclerotic Yucatan Micropig

BACKGROUND Arterial remodeling after balloon angioplasty has been recognized as a major determinant of restenosis. Perturbation of collagen metabolism might be important. After balloon injury, matrix metalloproteinase (MMP) expression is upregulated. We investigated the effect of Batimastat, a nonspecific MMP inhibitor, on late lumen loss, arterial remodeling, and neointima formation after balloon dilation. METHODS AND RESULTS In atherosclerotic iliac arteries of 12 Yucatan micropigs, balloon dilation was performed, with intravascular ultrasound and quantitative angiography used before and after balloon dilation and at 42-day follow-up. The animals were randomly divided into 2 groups, the Batimastat group (n=6) and the vehicle group (n=6). All animals were intraperitoneally injected with either Batimastat or a vehicle immediately after balloon dilation and at 2 weeks and 4 weeks after balloon dilation. Angiographic and echographic late lumen loss in the Batimastat group versus the vehicle group was 0.3+/-0.1 versus 0.8+/-0.1 mm (P=0.01) and 2.2+/-0.5 versus 4.9+/-0.7 mm(2) (P=0.004), respectively. Late media-bounded area loss was used as a measure of remodeling after balloon dilation and was 0.9+/-0.6 mm(2) in the Batimastat group compared with 3.8+/-0.8 mm(2) in the vehicle group (P=0.003, mixed model analysis P=0.01). Neointima formation was 1.3+/-0.3 mm(2) in the Batimastat group and 1.0+/-0.2 mm(2) in the vehicle group (P=0. 542). CONCLUSIONS Metalloproteinase inhibition by Batimastat significantly reduced late lumen loss after balloon angioplasty by inhibition of constrictive arterial remodeling, whereas neointima formation was not inhibited by MMP inhibition.

Arterial Remodeling After Balloon Angioplasty or Stenting in an Atherosclerotic Experimental Model

BACKGROUND Recent studies have indicated that coronary restenosis after balloon angioplasty is the sum of geometric remodeling and neointimal formation. A proportional relationship between acute gain and late lumen loss has been observed in clinical trials. The aims of this study were to evaluate (1) the contribution of geometric remodeling and neointimal formation to the proportional gain-loss relationship after PTA or stenting and (2) the relationship between geometric remodeling and neointimal formation. METHODS AND RESULTS In atherosclerotic iliac arteries of 29 Yucatan micropigs, PTA or stenting was performed, with serial intravascular ultrasound (IVUS) and quantitative angiography before and after intervention and at 2 or 42 days of follow-up, followed by histomorphometrical analysis. For PTA at 42 days, late lumen loss by IVUS correlated strongly with geometric remodeling, expressed as late media-bounded area (MBA) loss (R2=.843, P<.001, n=20), and correlated weakly with intimal hyperplasia area (R2=.214, P=.02). For stented arteries, however, late lumen loss correlated moderately with intimal hyperplasia (R2=.367, P=.01, n=18) and only weakly with geometric remodeling (R2=.195, P=.04). Late lumen loss and late MBA loss of reference segments were observed at 42 days, especially in PTA arteries. Intimal hyperplasia and geometric remodeling were not correlated. CONCLUSIONS In this experimental model, the proportional relationship between acute gain and late lumen loss is mainly due to the proportional relationship between acute gain and geometric remodeling for PTA and between acute gain and intimal hyperplasia for stents. Finally, neointimal formation and remodeling seem to be unrelated processes.

Intracoronary Versus Intravenous Administration of Abciximab in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention With Thrombus Aspiration: The Comparison of Intracoronary Versus Intravenous Abciximab Administration During Emergency Reperfusion of ST-Segment Elevation Myocardial Infarction (CICERO) Trial

Background— Administration of the glycoprotein IIb/IIIa inhibitor abciximab is an effective adjunctive treatment strategy during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. Although small-scale studies have suggested beneficial effects of intracoronary over intravenous administration of abciximab, this has not been investigated in a medium-scale randomized clinical trial. Methods and Results— A total of 534 ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention with thrombus aspiration within 12 hours of symptom onset were randomized to either an intracoronary or an intravenous bolus of abciximab (0.25 mg/kg). Patients were pretreated with aspirin, heparin, and clopidogrel. The primary end point was the incidence of restored myocardial reperfusion, defined as complete ST-segment resolution. Secondary end points included myocardial reperfusion as assessed by myocardial blush grade, enzymatic infarct size, and major adverse cardiac events at 30 days. The incidence of complete ST-segment resolution was similar in the intracoronary and intravenous groups (64% versus 62%; P=0.562). However, the incidence of myocardial blush grade 2/3 was higher in the intracoronary group than in the intravenous group (76% versus 67%; P=0.022). Furthermore, enzymatic infarct size was smaller in the intracoronary than in the intravenous group (P=0.008). The incidence of major adverse cardiac events was similar in both groups (5.5% versus 6.1%; P=0.786). Conclusions— In ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention with thrombus aspiration, intracoronary administration of abciximab compared with intravenous administration does not improve myocardial reperfusion as assessed by ST-segment resolution. However, intracoronary administration is associated with improved myocardial reperfusion as assessed by myocardial blush grade and a smaller enzymatic infarct size. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00927615.

Impact of Pretreatment With Clopidogrel on Initial Patency and Outcome in Patients Treated With Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction. A Systematic Review

Background— The main goal of the initial treatment of ST-segment elevation myocardial infarction is prompt reperfusion of the infarct-related artery. The value of pretreatment with clopidogrel before primary percutaneous coronary intervention is currently unclear. Methods and Results— Studies were retrieved through MEDLINE and Cochrane Controlled Trials Register searches over the past 20 years. Two authors independently performed the study selection and data extraction. Randomized controlled studies were included when the research subjects were unselected patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. Pilot trials, studies that enrolled patients undergoing rescue percutaneous coronary intervention, and studies with angiographic assessment not performed by a core laboratory or 2 blinded investigators were excluded. Thirty-eight treatment groups, including 8429 patients, were included. Initial patency was higher in treatment groups in which patients received pretreatment with clopidogrel (34.3%; 95% confidence interval, 32.9 to 35.8) compared with those in which patients did not receive clopidogrel before initial coronary angiography (25.8%; 95% confidence interval, 24.5 to 27.1). In multivariate-weighted logistic regression analysis, pretreatment with clopidogrel was an independent predictor of early reperfusion (odds ratio, 1.51; 95% confidence interval, 1.31 to 1.74; P<0.0001) and improved clinical outcome. Conclusions— Initial patency and clinical outcome were improved in treatment groups that received pretreatment with clopidogrel. These results in patients undergoing primary percutaneous coronary intervention are in line with the experience of pretreatment with clopidogrel in elective patients, non–ST-elevation coronary syndromes, and thrombolytic studies.

Effect of metformin on left ventricular function after acute myocardial infarction in patients without diabetes: the GIPS-III randomized clinical trial

IMPORTANCE Metformin treatment is associated with improved outcome after myocardial infarction in patients with diabetes. In animal experimental studies metformin preserves left ventricular function. OBJECTIVE To evaluate the effect of metformin treatment on preservation of left ventricular function in patients without diabetes presenting with ST-segment elevation myocardial infarction (STEMI). DESIGN, SETTING, AND PARTICIPANTS Double-blind, placebo-controlled study conducted among 380 patients who underwent primary percutaneous coronary intervention (PCI) for STEMI at the University Medical Center Groningen, The Netherlands, between January 1, 2011, and May 26, 2013. INTERVENTIONS Metformin hydrochloride (500 mg) (n = 191) or placebo (n = 189) twice daily for 4 months. MAIN OUTCOMES AND MEASURES The primary efficacy measure was left ventricular ejection fraction (LVEF) after 4 months, assessed by magnetic resonance imaging. A secondary efficacy measure was the N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration after 4 months. The incidence of major adverse cardiac events (MACE; the combined end point of death, reinfarction, or target-lesion revascularization) was recorded until 4 months as a secondary efficacy measure. RESULTS At 4 months, all patients were alive and none were lost to follow-up. LVEF was 53.1% (95% CI, 51.6%-54.6%) in the metformin group (n = 135), compared with 54.8% (95% CI, 53.5%-56.1%) (P = .10) in the placebo group (n = 136). NT-proBNP concentration was 167 ng/L in the metformin group (interquartile range [IQR], 65-393 ng/L) and 167 ng/L in the placebo group (IQR, 74-383 ng/L) (P = .66). MACE were observed in 6 patients (3.1%) in the metformin group and in 2 patients (1.1%) in the placebo group (P = .16). Creatinine concentration (79 µmol/L [IQR, 70-87 µmol/L] vs 79 µmol/L [IQR, 72-89 µmol/L], P = .61) and glycated hemoglobin (5.9% [IQR, 5.6%-6.1%] vs 5.9% [IQR, 5.7%-6.1%], P = .15) were not significantly different between both groups. No cases of lactic acidosis were observed. CONCLUSIONS AND RELEVANCE Among patients without diabetes presenting with STEMI and undergoing primary PCI, the use of metformin compared with placebo did not result in improved LVEF after 4 months. The present findings do not support the use of metformin in this setting. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01217307.