D. Christopher Metzger

Platelet reactivity and clinical outcomes after coronary artery implantation of drug-eluting stents (ADAPT-DES): a prospective multicentre registry study

BACKGROUND The relation between platelet reactivity and stent thrombosis, major bleeding, and other adverse events after coronary artery implantation of drug-eluting stents has been incompletely characterised. We aimed to determine the relation between platelet reactivity during dual therapy with aspirin and clopidogrel and clinical outcomes after successful coronary drug-eluting stent implantation. METHODS ADAPT-DES was a prospective, multicentre registry of patients successfully treated with one or more drug-eluting stents and given aspirin and clopidogrel at 10-15 US and European hospitals. We assessed platelet reactivity in those patients after successful percutaneous coronary intervention using VerifyNow point-of-care assays, and assigned different cutoffs to define high platelet reactivity. The primary endpoint was definite or probable stent thrombosis; other endpoints were all-cause mortality, myocardial infarction, and clinically relevant bleeding. We did a propensity-adjusted multivariable analysis to determine the relation between platelet reactivity and subsequent adverse events. This study is registered with ClinicalTrials.gov, number NCT00638794. FINDINGS Between Jan 7, 2008, and Sept 16, 2010, 8665 patients were prospectively enrolled at 11 sites, of which 8583 were eligible. At 1-year follow-up, stent thrombosis had occurred in 70 (0·8%) patients, myocardial infarction in 269 (3·1%), clinically relevant bleeding in 531 (6·2%), and death in 161 (1·9%) patients. High platelet reactivity on clopidogrel was strongly related to stent thrombosis (adjusted HR 2·49 [95% CI 1·43-4·31], p=0·001) and myocardial infarction (adjusted HR 1·42 [1·09-1·86], p=0·01), was inversely related to bleeding (adjusted HR 0·73 [0·61-0·89], p=0·002), but was not related to mortality (adjusted HR 1·20 [0·85-1·70], p=0·30). High platelet reactivity on aspirin was not significantly associated with stent thrombosis (adjusted HR 1·46 [0·58-3·64], p=0·42), myocardial infarction, or death, but was inversely related to bleeding (adjusted HR 0·65 [0·43-0·99], p=0·04). INTERPRETATION The findings from this study emphasise the counter-balancing effects of haemorrhagic and ischaemic complications after stent implantation, and suggest that safer drugs or tailored strategies for the use of more potent agents must be developed if the benefits of greater platelet inhibition in patients with cardiovascular disease are to be realised. FUNDING Boston Scientific, Abbott Vascular, Medtronic, Cordis, Biosensors, The Medicines Company, Daiichi-Sankyo, Eli Lilly, Volcano, and Accumetrics.

Intracoronary Abciximab and Aspiration Thrombectomy in Patients With Large Anterior Myocardial Infarction The INFUSE-AMI Randomized Trial

CONTEXT Thrombus embolization during percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) is common and results in suboptimal myocardial perfusion and increased infarct size. Two strategies proposed to reduce distal embolization and improve outcomes after primary PCI are bolus intracoronary abciximab and manual aspiration thrombectomy. OBJECTIVE To determine whether bolus intracoronary abciximab, manual aspiration thrombectomy, or both reduce infarct size in high-risk patients with STEMI. DESIGN, SETTING, AND PATIENTS Between November 28, 2009, and December 2, 2011, 452 patients presenting at 37 sites in 6 countries within 4 hours of STEMI due to proximal or mid left anterior descending artery occlusion undergoing primary PCI with bivalirudin anticoagulation were randomized in an open-label, 2 x 2 factorial design to bolus intracoronary abciximab delivered locally at the infarct lesion site vs no abciximab and to manual aspiration thrombectomy vs no thrombectomy. INTERVENTIONS A 0.25-mg/kg bolus of abciximab was administered at the site of the infarct lesion via a local drug delivery catheter. Manual aspiration thrombectomy was performed with a 6 F aspiration catheter. MAIN OUTCOME MEASURES Primary end point: infarct size (percentage of total left ventricular mass) at 30 days assessed by cardiac magnetic resonance imaging (cMRI) in the abciximab vs no abciximab groups (pooled across the aspiration randomization); major secondary end point: 30-day infarct size in the aspiration vs no aspiration groups (pooled across the abciximab randomization). RESULTS Evaluable cMRI results at 30 days were present in 181 and 172 patients randomized to intracoronary abciximab vs no abciximab, respectively, and in 174 and 179 patients randomized to manual aspiration vs no aspiration, respectively. Patients randomized to intracoronary abciximab compared with no abciximab had a significant reduction in 30-day infarct size (median, 15.1%; interquartile range [IQR], 6.8%-22.7%; n = 181, vs 17.9% [IQR, 10.3%-25.4%]; n = 172; P = .03). Patients randomized to intracoronary abciximab also had a significant reduction in absolute infarct mass (median, 18.7 g [IQR, 7.4-31.3 g]; n = 184, vs 24.0 g [IQR, 12.1-34.2 g]; n = 175; P = .03) but not abnormal wall motion score (median, 7.0 [IQR, 2.0-10.0]; n = 188, vs 8.0 [IQR, 3.0-10.0]; n = 184; P = .08). Patients randomized to aspiration thrombectomy vs no aspiration had no significant difference in infarct size at 30 days (median, 17.0% [IQR, 9.0%-22.8%]; n = 174, vs 17.3% [IQR, 7.1%-25.5%]; n = 179; P = .51), absolute infarct mass (median, 20.3 g [IQR, 9.7-31.7 g]; n = 178, vs 21.0 g [IQR, 9.1-34.1 g]; n = 181; P = .36), or abnormal wall motion score (median, 7.5 [IQR, 2.0-10.0]; n = 186, vs 7.5 [IQR, 2.0-10.0]; n = 186; P = .89). CONCLUSION In patients with large anterior STEMI presenting early after symptom onset and undergoing primary PCI with bivalirudin anticoagulation, infarct size at 30 days was significantly reduced by bolus intracoronary abciximab delivered to the infarct lesion site but not by manual aspiration thrombectomy. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00976521.

Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease

BACKGROUND In patients with coronary artery disease who receive metallic drug-eluting coronary stents, adverse events such as late target-lesion failure may be related in part to the persistent presence of the metallic stent frame in the coronary-vessel wall. Bioresorbable vascular scaffolds have been developed to attempt to improve long-term outcomes. METHODS In this large, multicenter, randomized trial, 2008 patients with stable or unstable angina were randomly assigned in a 2:1 ratio to receive an everolimus-eluting bioresorbable vascular (Absorb) scaffold (1322 patients) or an everolimus-eluting cobalt-chromium (Xience) stent (686 patients). The primary end point, which was tested for both noninferiority (margin, 4.5 percentage points for the risk difference) and superiority, was target-lesion failure (cardiac death, target-vessel myocardial infarction, or ischemia-driven target-lesion revascularization) at 1 year. RESULTS Target-lesion failure at 1 year occurred in 7.8% of patients in the Absorb group and in 6.1% of patients in the Xience group (difference, 1.7 percentage points; 95% confidence interval, -0.5 to 3.9; P=0.007 for noninferiority and P=0.16 for superiority). There was no significant difference between the Absorb group and the Xience group in rates of cardiac death (0.6% and 0.1%, respectively; P=0.29), target-vessel myocardial infarction (6.0% and 4.6%, respectively; P=0.18), or ischemia-driven target-lesion revascularization (3.0% and 2.5%, respectively; P=0.50). Device thrombosis within 1 year occurred in 1.5% of patients in the Absorb group and in 0.7% of patients in the Xience group (P=0.13). CONCLUSIONS In this large-scale, randomized trial, treatment of noncomplex obstructive coronary artery disease with an everolimus-eluting bioresorbable vascular scaffold, as compared with an everolimus-eluting cobalt-chromium stent, was within the prespecified margin for noninferiority with respect to target-lesion failure at 1 year. (Funded by Abbott Vascular; ABSORB III ClinicalTrials.gov number, NCT01751906.).

Relationship Between Intravascular Ultrasound Guidance and Clinical Outcomes After Drug-Eluting Stents The Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) Study

Background— Prior small to modest-sized studies suggest a benefit of intravascular ultrasound (IVUS) guidance in noncomplex lesions. Whether IVUS guidance is associated with improved clinical outcomes after drug-eluting stent (DES) implantation in an unrestricted patient population is unknown. Methods and Results— Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter, nonrandomized “all-comers” study of 8583 consecutive patients at 11 international centers designed to determine the frequency, timing, and correlates of stent thrombosis and adverse clinical events after DES. Propensity-adjusted multivariable analysis was performed to examine the relationship between IVUS guidance and 1-year outcomes. IVUS was utilized in 3349 patients (39%), and larger-diameter devices, longer stents, and/or higher inflation pressures were used in 74% of IVUS-guided cases. IVUS guidance compared with angiography guidance was associated with reduced 1-year rates of definite/probable stent thrombosis (0.6% [18 events] versus 1.0% [53 events]; adjusted hazard radio, 0.40; 95% confidence interval, 0.21–0.73; P=0.003), myocardial infarction (2.5% versus 3.7%; adjusted hazard radio, 0.66; 95% confidence interval, 0.49–0.88; P=0.004), and composite adjudicated major adverse cardiac events (ie, cardiac death, myocardial infarction, or stent thrombosis) (3.1% versus 4.7%; adjusted hazard radio, 0.70; 95% confidence interval, 0.55–0.88; P=0.002). The benefits of IVUS were especially evident in patients with acute coronary syndromes and complex lesions, although significant reductions in major adverse cardiac events were present in all patient subgroups those with including stable angina and single-vessel disease. Conclusions— In ADAPT-DES, the largest study of IVUS use to date, IVUS guidance was associated with a reduction in stent thrombosis, myocardial infarction, and major adverse cardiac events within 1 year after DES implantation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Relationship Between Intravascular Ultrasound Guidance and Clinical Outcomes After Drug-Eluting Stents: The ADAPT-DES Study

Background— Prior small to modest-sized studies suggest a benefit of intravascular ultrasound (IVUS) guidance in noncomplex lesions. Whether IVUS guidance is associated with improved clinical outcomes after drug-eluting stent (DES) implantation in an unrestricted patient population is unknown. Methods and Results— Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter, nonrandomized “all-comers” study of 8583 consecutive patients at 11 international centers designed to determine the frequency, timing, and correlates of stent thrombosis and adverse clinical events after DES. Propensity-adjusted multivariable analysis was performed to examine the relationship between IVUS guidance and 1-year outcomes. IVUS was utilized in 3349 patients (39%), and larger-diameter devices, longer stents, and/or higher inflation pressures were used in 74% of IVUS-guided cases. IVUS guidance compared with angiography guidance was associated with reduced 1-year rates of definite/probable stent thrombosis (0.6% [18 events] versus 1.0% [53 events]; adjusted hazard radio, 0.40; 95% confidence interval, 0.21–0.73; P=0.003), myocardial infarction (2.5% versus 3.7%; adjusted hazard radio, 0.66; 95% confidence interval, 0.49–0.88; P=0.004), and composite adjudicated major adverse cardiac events (ie, cardiac death, myocardial infarction, or stent thrombosis) (3.1% versus 4.7%; adjusted hazard radio, 0.70; 95% confidence interval, 0.55–0.88; P=0.002). The benefits of IVUS were especially evident in patients with acute coronary syndromes and complex lesions, although significant reductions in major adverse cardiac events were present in all patient subgroups those with including stable angina and single-vessel disease. Conclusions— In ADAPT-DES, the largest study of IVUS use to date, IVUS guidance was associated with a reduction in stent thrombosis, myocardial infarction, and major adverse cardiac events within 1 year after DES implantation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Long-term impact of chronic kidney disease in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention: the HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction) trial.

OBJECTIVES This study sought to investigate the impact of chronic kidney disease (CKD) in patients undergoing percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) with different antithrombotic strategies. BACKGROUND CKD is associated with increased risk of adverse ischemic and hemorrhagic events after primary PCI for STEMI. METHODS HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction) trial was a multicenter, international, randomized trial comparing bivalirudin monotherapy or heparin plus a glycoprotein IIb/IIIa inhibitor (GPI) during primary PCI in STEMI. CKD, defined as creatinine clearance <60 ml/min, was present at baseline in 554 of 3,397 patients (16.3%). Patients were followed for 3 years. Net adverse cardiac event (NACE) was defined as the composite of death, reinfarction, ischemia-driven target vessel revascularization (TVR), stroke or non-coronary artery bypass grafting (CABG)-related major bleeding. RESULTS Patients with CKD compared with patients without had higher rates of NACE (41.4% vs. 23.8%, p < 0.0001), death (18.7% vs. 4.4%, p < 0.0001), and major bleeding (19.3% vs. 6.7%, p < 0.0001). Multivariable analysis identified baseline creatinine as an independent predictor of death at 3 years (hazard ratio: 1.51, 95% confidence interval: 1.21 to 1.87, p < 0.001). Patients with CKD randomized to bivalirudin monotherapy versus heparin plus GPI had no significant difference in major bleeding (19.0% vs. 19.6%, p = 0.72) or death (19.0% vs. 18.4%, p = 0.88) at 3 years. In patients with CKD, there was no difference in the rates of TVR in bare-metal stents (BMS) versus drug-eluting stents (DES) at 3 years (14.1% vs. 15.1%, p = 0.8). CONCLUSIONS STEMI patients with CKD have significantly higher rates of death and major bleeding compared with those without CKD. In patients with CKD, there appears to be no benefit of bivalirudin compared with heparin + GPI, or DES versus BMS during primary PCI in improving clinical outcomes.

Effect of Supersaturated Oxygen Delivery on Infarct Size After Percutaneous Coronary Intervention in Acute Myocardial Infarction

Background—Myocardial salvage is often suboptimal after percutaneous coronary intervention in ST-segment elevation myocardial infarction. Posthoc subgroup analysis from a previous trial (AMIHOT I) suggested that intracoronary delivery of supersaturated oxygen (SSO2) may reduce infarct size in patients with large ST-segment elevation myocardial infarction treated early. Methods and Results—A prospective, multicenter trial was performed in which 301 patients with anterior ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention within 6 hours of symptom onset were randomized to a 90-minute intracoronary SSO2 infusion in the left anterior descending artery infarct territory (n=222) or control (n=79). The primary efficacy measure was infarct size in the intention-to-treat population (powered for superiority), and the primary safety measure was composite major adverse cardiovascular events at 30 days in the intention-to-treat and per-protocol populations (powered for noninferiority), with Bayesian hierarchical modeling used to allow partial pooling of evidence from AMIHOT I. Among 281 randomized patients with tc-99m-sestamibi single-photon emission computed tomography data in AMIHOT II, median (interquartile range) infarct size was 26.5% (8.5%, 44%) with control compared with 20% (6%, 37%) after SSO2. The pooled adjusted infarct size was 25% (7%, 42%) with control compared with 18.5% (3.5%, 34.5%) after SSO2 (PWilcoxon=0.02; Bayesian posterior probability of superiority, 96.9%). The Bayesian pooled 30-day mean (±SE) rates of major adverse cardiovascular events were 5.0±1.4% for control and 5.9±1.4% for SSO2 by intention-to-treat, and 5.1±1.5% for control and 4.7±1.5% for SSO2 by per-protocol analysis (posterior probability of noninferiority, 99.5% and 99.9%, respectively). Conclusions—Among patients with anterior ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention within 6 hours of symptom onset, infusion of SSO2 into the left anterior descending artery infarct territory results in a significant reduction in infarct size with noninferior rates of major adverse cardiovascular events at 30 days. Clinical Trial Registration—clinicaltrials.gov Identifier: NCT00175058

Randomized Controlled Study of Excimer Laser Atherectomy for Treatment of Femoropopliteal In-Stent Restenosis: Initial Results From the EXCITE ISR Trial (EXCImer Laser Randomized Controlled Study for Treatment of FemoropopliTEal In-Stent Restenosis)

OBJECTIVES The purpose of this study was to evaluate the safety and efficacy of excimer laser atherectomy (ELA) with adjunctive percutaneous transluminal angioplasty (PTA) versus PTA alone for treating patients with chronic peripheral artery disease with femoropopliteal bare nitinol in-stent restenosis (ISR). BACKGROUND Femoropopliteal stenting has shown superiority to PTA for lifestyle-limiting claudication and critical limb ischemia, although treating post-stenting artery reobstruction, or ISR, remains challenging. METHODS The multicenter, prospective, randomized, controlled EXCITE ISR (EXCImer Laser Randomized Controlled Study for Treatment of FemoropopliTEal In-Stent Restenosis) trial was conducted across 40 U.S. centers. Patients with Rutherford Class 1 to 4 and lesions of target lesion length ≥4 cm, vessel diameter 5 to 7 mm were enrolled and randomly divided into ELA + PTA and PTA groups by a 2:1 ratio. The primary efficacy endpoint was target lesion revascularization (TLR) at 6-month follow up. The primary safety endpoint was major adverse event (death, amputation, or TLR) at 30 days post-procedure. RESULTS Study enrollment was stopped at 250 patients due to early efficacy demonstrated at a prospectively-specified interim analysis. A total of 169 ELA + PTA subjects (62.7% male; mean age 68.5 ± 9.8 years) and 81 PTA patients (61.7% male; mean age 67.8 ± 10.3 years) were enrolled. Mean lesion length was 19.6 ± 12.0 cm versus 19.3 ± 11.9 cm, and 30.5% versus 36.8% of patients exhibited total occlusion. ELA + PTA subjects demonstrated superior procedural success (93.5% vs. 82.7%; p = 0.01) with significantly fewer procedural complications. ELA + PTA and PTA subject 6-month freedom from TLR was 73.5% versus 51.8% (p < 0.005), and 30-day major adverse event rates were 5.8% versus 20.5% (p < 0.001), respectively. ELA + PTA was associated with a 52% reduction in TLR (hazard ratio: 0.48; 95% confidence interval: 0.31 to 0.74). CONCLUSIONS The EXCITE ISR trial is the first large, prospective, randomized study to demonstrate superiority of ELA + PTA versus PTA alone for treating femoropopliteal ISR. (Randomized Study of Laser and Balloon Angioplasty Versus Balloon Angioplasty to Treat Peripheral In-stent Restenosis [EXCITE ISR]; NCT01330628).

A randomized trial of a dedicated bifurcation stent versus provisional stenting in the treatment of coronary bifurcation lesions

BACKGROUND Bifurcation lesions are frequent among patients with symptomatic coronary disease treated by percutaneous coronary intervention. Current evidence recommends a conservative (provisional) approach when treating the side branch (SB). OBJECTIVES The TRYTON (Prospective, Single Blind, Randomized Controlled Study to Evaluate the Safety & Effectiveness of the Tryton Side Branch Stent Used With DES in Treatment of de Novo Bifurcation Lesions in the Main Branch & Side Branch in Native Coronaries) bifurcation trial sought to compare treatment of de novo true bifurcation lesions using a dedicated bifurcation stent or SB balloon angioplasty. METHODS We randomly assigned patients with true bifurcation lesions to a main vessel stent plus provisional stenting or the bifurcation stent. The primary endpoint (powered for noninferiority) was target vessel failure (TVF) (cardiac death, target vessel myocardial infarction, and target vessel revascularization). The secondary angiographic endpoint (powered for superiority) was in-segment percent diameter stenosis of the SB at 9 months. RESULTS We randomized 704 patients with bifurcation coronary lesions at 58 centers (30 from Europe and 28 from the United States). At 9 months, TVF was 17.4% in the bifurcation stent group compared with 12.8% in the provisional group (p=0.11), mainly because of a higher periprocedural myocardial infarction rate (13.6% vs. 10.1%, p=0.19). The TVF difference of +4.6% (2-sided 95% confidence interval: -1.0 to 10.3; upper limit of the 1-sided 95% confidence interval: 10.3) was not within the pre-specified noninferiority margin of 5.5% (p=0.42 for noninferiority). The SB in-segment diameter stenosis among the angiographic cohort was lower in the bifurcation stent group compared with the provisional group (31.6% vs. 38.6%, p=0.002 for superiority), with no difference in binary restenosis rates (diameter stenosis≥50%) at 9 months follow-up (22.6% vs. 26.8%, p=0.44). CONCLUSIONS Provisional stenting should remain the preferred strategy for treatment of non-left main true coronary bifurcation lesions. (Prospective, Single Blind, Randomized Controlled Study to Evaluate the Safety & Effectiveness of the Tryton Side Branch Stent Used With DES in Treatment of de Novo Bifurcation Lesions in the Main Branch & Side Branch in Native Coronaries [TRYTON]; NCT01258972).

Safety and Feasibility of Robotic Percutaneous Coronary Intervention : PRECISE (Percutaneous Robotically-Enhanced Coronary Intervention) Study

OBJECTIVES The aim of this study was to evaluate the safety as well as the clinical and technical effectiveness of robotic-assisted percutaneous coronary intervention. BACKGROUND Robotic systems have been suggested to enhance the performance of cardiovascular procedures, as well as to provide protection from the occupational hazards that are associated with interventional practice. METHODS Patients with coronary artery disease and clinical indications for percutaneous intervention were enrolled. The coronary intervention was performed with the CorPath 200 robotic system, which consists of a remote interventional cockpit and a bedside disposable cassette that enables the operator to advance, retract, and rotate guidewires and catheters. The primary endpoints were clinical procedural success, defined as <30% residual stenosis at the completion of the robotic-assisted procedure without major adverse cardiovascular events within 30 days, and device technical success, defined as the successful manipulation of the intracoronary devices using the robotic system only. RESULTS A total of 164 patients were enrolled at 9 sites. Percutaneous coronary intervention was completed successfully without conversion to manual operation, and device technical success was achieved in 162 of 164 patients (98.8%). There were no device-related complications. Clinical procedural success was achieved in 160 of 164 patients (97.6%), whereas 4 (2.4%) had periprocedural non-Q-wave myocardial infarctions. No deaths, strokes, Q-wave myocardial infarctions, or revascularization occurred in the 30 days after the procedures. Radiation exposure for the primary operator was 95.2% lower than the levels found at the traditional table position. CONCLUSIONS This pivotal multicenter study with a robotic-enhanced coronary intervention system demonstrated the safety and feasibility of the system. The robotic remote-control procedure met the expected technical and clinical performance, with significantly lower radiation exposure to the operator. (Evaluation of the Safety and Effectiveness of the CorPath 200 System in Percutaneous Coronary Interventions [PCI] [PRECISE]; NCT01275092).