Dual Antiplatelet Therapy Discontinuation, Platelet Reactivity, and Adverse Outcomes After Successful Percutaneous Coronary Intervention.

OBJECTIVES: The purpose of this study was to assess the extent to which the association between premature dual antiplatelet therapy (DAPT) discontinuation and excess risk of thrombotic events varies according to the reason and timing of DAPT discontinuation and whether high on-treatment platelet reactivity (HPR) influences the risk of thrombotic events after premature DAPT discontinuation. BACKGROUND: DAPT after percutaneous coronary intervention (PCI) suppresses platelet reactivity, and HPR on clopidogrel after PCI is associated with an increased risk of thrombotic events. METHODS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of 8,582 patients successfully treated with coronary drug-eluting stents that assessed HPR on clopidogrel. For patients who discontinued aspirin or clopidogrel at any time during the study, the reasons for discontinuation were systematically categorized. RESULTS: Planned DAPT discontinuation occurred within 2 years in 3,203 (37.3%) patients. One thousand four hundred eighteen (16.5%) patients discontinued DAPT for unplanned reasons, including surgery or trauma (n = 768 [8.9%]), patient nonadherence (n = 321 [3.7%]), bleeding complications (n = 264 [3.1%]), and drug allergy or hypersensitivity (n = 113 [1.3%]). Unplanned but not planned DAPT discontinuation was associated with an increased risk of a major adverse cardiac event (MACE, defined as the composite of cardiac death, myocardial infarction, or stent thrombosis); with highest risk within 3 months after PCI (adjusted HR: 7.65, 95% CI: 2.77-21.10 vs adjusted HR: 2.47, 95% CI: 1.70-3.58 for unplanned DAPT discontinuation ≥3 weeks after PCI). MACE risk after DAPT discontinuation was not moderated by HPR (Pinteraction = 0.91). CONCLUSIONS: In this large-scale all-comers registry, premature DAPT discontinuation for unplanned reasons occurred in approximately 1 of 6 patients after DES implantation and was associated with a markedly increased risk of MACEs. (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents [ADAPT-DES]; NCT00638794).

Impact of Smoking on Platelet Reactivity and Clinical Outcomes After Percutaneous Coronary Intervention: Findings From the ADAPT-DES Study.

BACKGROUND: Smoking is a potent risk factor for coronary artery disease; however, prior studies describe increased platelet inhibition with clopidogrel among smokers, and some studies report improved outcomes among smokers, a finding described as the smoker's paradox. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among current smokers and nonsmokers. METHODS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between current smoking, platelet reactivity, and subsequent adverse events. RESULTS: Among 8582 patients, 22.6% were active smokers at the time of their percutaneous coronary intervention procedure. Current smokers were younger and had fewer comorbidities compared with nonsmokers. Current smokers had lower mean P2Y12 reaction units and lower rates of HPR compared with nonsmokers. Current smokers had similar rates of adverse events compared with nonsmokers. HPR was associated with higher rates of adverse events for both smokers and nonsmokers; however, there was evidence of interaction between smoking status and the effect of HPR. Smokers with HPR had significantly higher rates of stent thrombosis. Adverse event rates were highest among current smokers with HPR. CONCLUSIONS: Current smoking was associated with lower P2Y12 reaction units and lower rates of HPR on average; however, the combination of current smoking and HPR was associated with high rates of stent thrombosis. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Impact of Point-of-Care Platelet Function Testing Among Patients With and Without Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents (from the ADAPT-DES Study).

We sought to examine if the risk conferred by high on-treatment platelet reactivity (HPR) varies based upon clinical presentation. We examined the relation between HPR (P2Y12 reaction units >208) and adverse ischemic and bleeding events among patients with and without acute coronary syndromes (ACS) from ADAPT-DES; 51.7% of patients had ACS. After clopidogrel loading, ACS patients had higher P2Y12 reaction units and a greater prevalence of HPR based on VerifyNow P2Y12 assay. Of 92 definite or probable stent thrombosis (ST) events at 2 years, 65.2% occurred among patients with ACS. HPR was independently associated with ST in ACS patients (adjusted hazard ratio 2.29, 95% confidence interval 1.32 to 3.98) but not with clinically relevant bleeding. Although no statistical interactions between ACS status and these associations were observed, non-ACS patients exhibited an attenuated association between HPR and ST, and an inverse association between HPR and clinically relevant bleeding. HPR was similarly associated with myocardial infarction, but not with overall mortality in ACS and non-ACS patients. In conclusion, the majority of ST events in the 2 years after drug-eluting stent placement occurred in ACS patients; HPR was strongly associated with ST in these patients. These data support current recommendations for using more potent antiplatelet therapies in ACS patients.

Platelet Reactivity and Risk of Ischemic Stroke After Coronary Drug-Eluting Stent Implantation: From the ADAPT-DES Study.

OBJECTIVES: The authors sought to investigate the association between P2Y12 reaction units (PRU) and the risk of ischemic stroke (IS) after successful coronary drug-eluting stents (DES) implantation. BACKGROUND: The association between platelet reactivity on clopidogrel and the risk for ischemic cerebrovascular events remains unclear. METHODS: Incidence, predictors, and prognostic impact of IS were evaluated among patients enrolled in the multicenter, prospective ADAPT-DES (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents) study. By protocol, patients were maintained on aspirin for 2 years and clopidogrel for at least 1 year. Baseline platelet reactivity on clopidogrel and aspirin were assessed by means of VerifyNow point-of-care assay after successful DES implantation. RESULTS: Among 8,582 patients enrolled, 68 (0.8%) had an IS during 2-year follow-up. Across the spectrum of PRU, rates of IS were progressively greater as patients transitioned from the lowest quintile of PRU (more P2Y12 receptor inhibition; 2-year rate of 0.51%) to the highest quintile of PRU (less P2Y12 receptor inhibition; 2-year rate of 1.34%; adjusted p = 0.04). PRU >208 was independently associated with higher risk of IS at 2 years (adjusted hazard ratio 1.81; 95% confidence interval 1.08 to 3.04; p = 0.03). The association between higher PRU and risk for IS was also consistent in patients with versus without high CHA2DS2-VASc score (pinteraction = 0.30) and in those on or off oral anticoagulation at discharge (pinteraction = 0.99). Occurrence of IS was strongly associated with increased risk of all-cause mortality at 2 years (adjusted HR: 4.16; 95% CI: 1.95 to 8.87; p < 0.0001). CONCLUSIONS: Higher PRU was associated with increased risk of IS after coronary DES implantation. Ensuring adequate platelet P2Y12 receptor inhibition may reduce the risk of IS in this patient population. (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents [ADAPT-DES]; NCT00638794).

Platelet Reactivity and Clinical Outcomes After Coronary Artery Implantation of Drug-Eluting Stents in Subjects With Peripheral Arterial Disease: Analysis From the ADAPT-DES Study (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents).

BACKGROUND: Patients with peripheral arterial disease (PAD) have high rates of adverse cardiovascular events after percutaneous coronary intervention and may additionally have heightened platelet reactivity. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among subjects with and without PAD. METHODS AND RESULTS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between PAD, platelet reactivity, and subsequent adverse events (definite or probable stent thrombosis, all-cause mortality, myocardial infarction, and clinically relevant bleeding). Among 8582 patients, 10.2% had a history of PAD. Patients with PAD were older and more likely to have comorbid conditions; however, mean P2Y12 reaction units and HPR were not significantly different between PAD and no PAD groups. Patients with PAD had higher 2-year rates of all-cause mortality, myocardial infarction, stent thrombosis, and clinically relevant bleeding. Associations between HPR and adverse events were similar in PAD and no PAD groups, without evidence of interaction; however, adverse event rates were highest among subjects with both PAD and HPR. In a propensity-adjusted multivariable model, both PAD and HPR were independent predictors of myocardial infarction at 2 years. CONCLUSIONS: A history of PAD was associated with ischemic and bleeding outcomes 2 years after successful coronary drug-eluting stent implantation; however, these associations did not seem to be directly mediated by heightened platelet reactivity. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Sex Differences in the Clinical Impact of High Platelet Reactivity After Percutaneous Coronary Intervention With Drug-Eluting Stents: Results From the ADAPT-DES Study (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents).

BACKGROUND: Sex differences in the outcomes after percutaneous coronary intervention with drug-eluting stents and in the response to clopidogrel therapy have been reported; however, the differential risk of high platelet reactivity (HPR) on clopidogrel in women versus men is unknown. METHODS AND RESULTS: We compared 8448 patients enrolled in the ADAPT-DES study (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) according to sex and the presence/absence of HPR on clopidogrel (defined as P2Y12 reactivity units >208). Study end points were definite and probable stent thrombosis (ST), clinically relevant bleeding, all-cause mortality, myocardial infarction, and major adverse cardiac events (comprising mortality, myocardial infarction, and target lesion revascularization). HPR was more common among women (1118/2163, 51.7%) than men (2491/6285, 39.6%). HPR was associated with a roughly double risk of 1-year ST in both women and men (women with versus without HPR: 1.4% versus 0.7%; hazard ratio [HR], 2.02; 95% confidence interval [CI], 0.82-4.95; P=0.12; and men: 1.2% versus 0.5%; HR, 2.42; 95% CI, 1.36-4.30; P=0.002; Pinteraction=0.73). HPR was associated with almost half the rate of clinically relevant bleeding in women (women: HPR versus no HPR, 5.3% versus 9.8%; HR, 0.54; 95% CI, 0.40-0.74; P<0.001), whereas men had similar rates of bleeding regardless of HPR status (men: HPR versus no HPR, 5.7% versus 5.9%; HR, 0.96; 95% CI, 0.78-1.18; P=0.70; Pinteraction=0.003). In propensity-adjusted models, HPR was an independent predictor of ST and myocardial infarction in men; although both associations were nonsignificant among women, no interaction was observed in the associations between HPR and either ST or myocardial infarction. Conversely, HPR was an independent predictor of reduced bleeding only in women (women: adjusted HR, 0.58; 95% CI, 0.41-0.82; P=0.002; and men: adjusted HR, 0.83; 95% CI, 0.65-1.04; P=0.11; Pinteraction=0.01). CONCLUSIONS: In the current analysis, the associated risk of HPR for ST was similar in both sexes. However, HPR was associated with significantly reduced bleeding only among women. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Fixed and Modifiable Correlates of Drug-Eluting Stent Thrombosis From a Large All-Comers Registry: Insights From ADAPT-DES.

BACKGROUND: Previous studies evaluating correlates of stent thrombosis (ST) have included mostly patients with bare metal stents and early-generation drug-eluting stents (DES) and have not systematically evaluated the role of intravascular ultrasound-guided stenting and high platelet reactivity on clopidogrel. The purpose of this study was to evaluate the frequency and correlates of ST in patients receiving DES, specifically examining the impact of risk factors modifiable by physician and patient behavior. METHODS AND RESULTS: Assessment of Dual Anti-platelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a multicenter, prospective study in patients undergoing successful coronary intervention with DES in whom routine platelet reactivity testing was performed. Definite or probable ST occurred in 92 (1.1%) of 8582 patients within 2 years. Independent baseline correlates of ST included presentation with an acute coronary syndrome (hazard ratio [HR]=1.81, P=0.01), insulin-treated diabetes mellitus (HR=1.91, P=0.02), previous myocardial infarction (HR=1.75, P=0.02), and peripheral arterial disease (HR=2.01, P=0.01). Independent treatment-related correlates included use of early generation DES (HR=1.75, P=0.02), no procedural intravascular ultrasound guidance (HR=1.75, P=0.04), and premature discontinuation of dual antiplatelet therapy (HR=2.67, P=0.003); high platelet reactivity on clopidogrel trended as a correlate of ST (HR=1.49, P=0.08). The 2-year risk of ST ranged from 0.3% to 10.0% when 0 to 3 modifiable risk factors were present. CONCLUSIONS: After successful DES implantation, ST occurred within 2 years in 1.1% of patients and was strongly associated with fixed and modifiable risk factors. The frequency of ST may be reduced with intravascular ultrasound -guided stenting, assiduous adherence to dual antiplatelet therapy, and adequate P2Y12 platelet receptor inhibition. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Age-related effects of smoking on culprit lesion plaque vulnerability as assessed by grayscale and virtual histology-intravascular ultrasound.

BACKGROUND: Although smoking is a risk factor for coronary atherosclerosis, the age-related impact on lesion characteristics and plaque instability remains unclear. PATIENTS AND METHODS: In ADAPT-DES, 780 patients with 916 culprit lesions were evaluated by preprocedural grayscale and virtual histology-intravascular ultrasound. RESULTS: Current smokers (smoking within 1 month) more often presented with acute coronary syndrome (67 vs. 51 vs. 51%, P<0.05) compared with former smokers (no smoking for >1 month) or nonsmokers. In patients 65 or more years of age, current smokers (vs. nonsmokers) showed larger normalized volumes of plaque and media [8.6 (7.8-9.4) vs. 7.2 (6.8-7.7) mm/mm, P=0.016] and external elastic membrane [14.4 (13.2-15.5) vs. 12.8 (12.2-13.4) mm/mm, P=0.05]. At the minimal lumen area site, despite a greater plaque burden, the larger external elastic membrane area [14.4 (13.1-15.7) vs. 12.0 (11.3-12.7) mm, P=0.003] contributed toward preserving the minimal lumen area [2.6 (2.4-2.7) vs. 2.6 (2.5-2.7) mm, P=0.91] in current smokers (vs. nonsmokers) 65 or more years of age. Moreover, current smokers (vs. nonsmokers) 65 or more years of age showed a greater normalized necrotic core volume [1.19 (0.96-1.46) vs. 0.75 (0.66-0.85) mm/mm, P=0.0007], more thin-cap fibroatheromas (61 vs. 48%, P=0.04), and plaque ruptures (38 vs. 26%, P=0.051). Conversely, in patients younger than 65 years of age, there was no significant difference in culprit lesion morphology among current, former, and nonsmokers. CONCLUSION: In patients 65 or more years (not in patients<65 years), smoking increased culprit lesion plaque instability (greater plaque with more necrotic core, thin-cap fibroatheromas, positive remodeling, and plaque ruptures).

Predictors and impact of target vessel revascularization after stent implantation for acute ST-segment elevation myocardial infarction: lessons from HORIZONS-AMI.

BACKGROUND: Target vessel revascularization (TVR) may compromise the benefits of primary percutaneous coronary intervention in ST-segment elevation myocardial infarction (STEMI) We set out to identify the predictors and examine the impact of TVR after STEMI in patients receiving a coronary stent. METHODS: In HORIZONS-AMI, 3,602 patients with STEMI were randomized to bivalirudin versus heparin and a glycoprotein IIb/IIIa inhibitor. Stents were implanted in 3,202 patients (2,982 were randomized to bare-metal stents versus paclitaxel-eluting stents, and 220 received nonrandomized stents). RESULTS: Target vessel revascularization occurred in 219 patients (6.9%) at 1 year and in 437 patients (14.4%) at 3 years. Target vessel revascularization was ischemia-driven in 418 cases (95.7%). Target vessel revascularization was due to restenosis in 219 patients (50.1%), definite stent thrombosis in 124 (28.4%), and disease progression in 94 (21.5%). Independent predictors of TVR were more extensive coronary artery disease, smaller vessel size, longer lesion length and the number of stents implanted, post-percutaneous coronary intervention diameter stenosis, symptom onset to balloon time, treatment with bare-metal stents rather than paclitaxel-eluting stents, and scheduled angiographic follow-up. Target vessel revascularization was an independent predictor of subsequent myocardial infarction (hazard ratio [HR] 5.25, P < .0001), ST (HR 5.98, P < .0001), and major bleeding (HR 5.25, P < .0001) but not mortality (HR 0.88, P = .61). CONCLUSIONS: In HORIZONS-AMI, TVR within 3 years after stent implantation was performed in ~1 of every 7 patients and was associated with more extensive coronary disease, more complex procedures, and bare metal stents. Target vessel revascularization was often due to stent thrombosis and disease progression as well as restenosis and was strongly associated with adverse outcomes but not mortality.

Effect of Ischemia Duration and Door-to-Balloon Time on Myocardial Perfusion in ST-Segment Elevation Myocardial Infarction: An Analysis From HORIZONS-AMI Trial (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction).

OBJECTIVES: This study sought to investigate the effect of treatment delay on microvascular reperfusion in ST-segment elevation myocardial infarction (STEMI) patients from the large, multicenter, prospective HORIZONS-AMI (Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction) trial. BACKGROUND: Despite restoration of epicardial blood flow during primary percutaneous coronary intervention (PCI), one-third of patients do not obtain myocardial perfusion due to impairment in the microvascular circulation. METHODS: We examined the effect of symptom onset-to-balloon time (SBT) and door-to-balloon time (DBT) on myocardial reperfusion during primary PCI in STEMI, utilizing resolution of ST-segment elevation (STR) and the myocardial blush grade (MBG). The primary analysis was the relationships between SBT ≤2, >2 to 4, and >4 h and DBT ≤1, >1 to 1.5, >1.5 to 2, and >2 h with MBG and STR. Clinical risk was assessed using a modified version of the Thrombolysis In Myocardial Infarction risk score for STEMI. RESULTS: In 2,056 patients, absent microvascular perfusion (MBG 0/1) and STR (STR <30%) after primary PCI was significantly more common in patients with longer SBT, in patients with both low and high clinical risk profiles. By multivariable analysis, SBT (p < 0.0001), anterior infarction (p < 0.0001), reference vessel diameter (p = 0.005), lesion minimum lumen diameter (p < 0.0001), hyperlipidemia (p = 0.03), and current smoking (p = 0.001) were independent predictors of MBG 0/1, whereas SBT (p = 0.007), anterior infarction (p < 0.0001), and history of renal insufficiency (p = 0.0002) were independent predictors of absent STR. DBT (p < 0.0001) was an independent predictor of MBG 0/1. MBG 0/1 and STR<30% identified patients with increased 3-year mortality. CONCLUSIONS: The present study suggests that delay in mechanical reperfusion therapy during STEMI is associated with greater injury to the microcirculation.

Is There an Ideal Level of Platelet P2Y12-Receptor Inhibition in Patients Undergoing Percutaneous Coronary Intervention?: "Window" Analysis From the ADAPT-DES Study (Assessment of Dual AntiPlatelet Therapy With Drug-Eluting Stents).

OBJECTIVES: This study sought to determine whether there is an ideal level of platelet reactivity (PR) to optimize safety and efficacy within the large multicenter ADAPT-DES (Assessment of Dual AntiPlatelet Therapy With Drug-Eluting Stents) study of 8,582 patients receiving successful drug-eluting stent implantation. BACKGROUND: Patients with high PR on clopidogrel have a greater incidence of adverse ischemic events after stent implantation, whereas low PR may increase bleeding. Due to limited sample size, previous studies have not been able to adjust for differences in baseline characteristics that may confound the relationship of PR and outcomes. METHODS: In the ADAPT-DES study, routine platelet function testing (VerifyNow) was performed following clopidogrel loading. To characterize the independent association between PR and clinical events, patients were stratified into quintiles of P2Y12 reaction units (PRU). RESULTS: The PRU medians of the 5 quintiles were 57, 130, 187, 244, and 317 (most to least inhibited). There was a monotonic association between successively higher PRU quintiles and stent thrombosis, whereas for clinically relevant bleeding, the greatest risk occurred in the lowest PRU quintile, with similar risks across the 4 higher quintiles. These relationships remained significant in fully adjusted multivariable analyses (adjusted hazard ratio [HR] for stent thrombosis in Q5 versus Q1: 2.32; 95% confidence interval [CI]: 1.17 to 4.59; p = 0.02; adjusted HR for clinically relevant bleeding in Q5 versus Q1: 0.61; 95% CI: 0.47 to 0.77; p < 0.001). However, there were no significant independent associations between the level of PRU and mortality. CONCLUSIONS: In this large observational study, increasing PRU was associated with a monotonic increase in stent thrombosis, whereas bleeding risk was confined to the lowest PRU quintile, suggesting an optimal therapeutic window of platelet inhibition at moderately inhibited PRU. However, there was no demonstrable threshold effect for PRU and mortality in adjusted analyses, perhaps due to the offsetting impact of bleeding and ischemia across the spectrum of platelet inhibition. (Assessment of Dual AntiPlatelet Therapy With Drug-Eluting Stents [ADAPT-DES]; NCT00638794).

Incidence, predictors, and implications of reinfarction after primary percutaneous coronary intervention in ST-segment-elevation myocardial infarction: the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction Trial.

BACKGROUND: Reinfarction after primary percutaneous coronary intervention in patients with ST-segment-elevation myocardial infarction has negative consequences. Little is known about reinfarction after drug-eluting stents and bivalirudin anticoagulation. We, therefore, sought to determine the incidence, predictors, and implications of reinfarction after primary percutaneous coronary intervention in the contemporary era. METHODS AND RESULTS: Outcomes were assessed in 3202 patients undergoing stent implantation for ST-segment-elevation myocardial infarction in the Harmonizing Outcomes with RevascularIZatiON and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial. Independent predictors of reinfarction and mortality were identified by Cox proportional hazards modeling. The cumulative incidence of reinfarction was 1.8% at 30 days, 4.0% at 1 year, and 6.9% at 3 years. Definite stent thrombosis was responsible for 76.3% of reinfarctions occurring within 30 days and 52.0% of all reinfarctions within 3 years. Independent predictors of reinfarction were current smoking, Killip class ≥2, baseline thrombocytosis, multivessel disease, symptom onset-to-balloon time, and total stent length. Randomization to bivalirudin versus heparin plus a glycoprotein IIb/IIIa inhibitor and use of drug-eluting versus bare metal stents were not significant predictors of reinfarction. Reinfarction was a powerful independent predictor of subsequent cardiac mortality (hazard ratio [95% confidence interval]=7.65 [4.47-13.09]; P<0.0001) and all-cause mortality (hazard ratio [95% confidence interval]=2.88 [1.74-4.78]; P<0.0001). CONCLUSIONS: Despite advances in pharmacotherapy and stents, reinfarction after primary percutaneous coronary intervention is not infrequent, in the contemporary era is most often attributable to stent thrombosis, and is strongly associated with subsequent cardiac and all-cause mortality. Further enhancements in drugs and devices to prevent reinfarction are needed to improve outcomes in high-risk patients with ST-segment-elevation myocardial infarction. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00433966.

Frequency, mechanisms, and implications of late peri-stent contrast staining: analysis (from the HORIZONS-AMI Trial).

Previous studies have suggested that angiographically detected persistent contrast staining (PSS) at follow-up may predict subsequent very late stent thrombosis. The Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial was a dual-arm, factorial, randomized trial in patients with ST-segment elevation myocardial infarctions. All follow-up angiograms (1,330 lesions in 1,115 patients, median time 13.3 months) without major cardiovascular events before follow-up angiography were analyzed at a core laboratory blinded to clinical events for the presence of PSS (defined as contrast staining outside the stent contour extending to ≥20% of the stent diameter). Corresponding follow-up intravascular ultrasound (IVUS) data (275 lesions in 248 patients) were also evaluated to assess the mechanisms of PSS. PSS was present in 23 patients (2.1%) at follow-up and was not more common with paclitaxel-eluting than with bare-metal stents. All 6 PSS patients with follow-up IVUS had stent malapposition (vs 41.2% malapposition in the follow-up IVUS cohort). Comparing poststent and follow-up IVUS, 2 patients had late acquired and 4 had persistent malapposition; all 6 showed positive vessel remodeling from baseline to follow-up (mean vessel area 22.0 ± 8.0 to 32.4 ± 11.7 mm(2), p = 0.07). During 3-year follow-up, stent thrombosis developed in no patient with PSS compared with 8 PSS-negative patients (0% vs 0.8%, p = 0.68). The rates of revascularization and major adverse cardiovascular events were also not increased in PSS patients. In conclusion, in the large-scale HORIZONS-AMI trial, PSS at angiographic follow-up was infrequent and was associated with late stent malapposition and positive remodeling but was independent of stent type. Identification of PSS was not associated with subsequent stent thrombosis.

Comparison of outcomes of patients with ST-segment elevation myocardial infarction with versus without previous coronary artery bypass grafting (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction [HORIZONS-AMI] trial).

The present substudy from the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial assessed the outcomes and their relation to different antithrombotic regimens in patients with previous coronary artery bypass grafting (CABG) treated with primary percutaneous coronary intervention. Of 3,599 patients with information regarding a history of CABG, 105 (2.9%) had previously undergone CABG. Of these 105 patients, 46 were randomized to heparin plus a glycoprotein IIb/IIIa inhibitor and 59 to bivalirudin. The patients with versus without previous CABG were less frequently triaged to primary percutaneous coronary intervention (83.8% vs 93.2%, p = 0.0002) and had a longer door-to-balloon time (median 1.9 vs 1.6 hours, p = 0.047), lower rates of final Thrombolysis In Myocardial Infarction flow grade 2 to 3 in the intervened vessel (92.6% vs 97.8%, p = 0.007), and less frequent rates of complete or partial ST-segment resolution (66.3% vs 77.6%, p = 0.019). At 3 years, previous CABG was associated with a significantly greater incidence of major adverse cardiovascular events (36.4% vs 21.4%, p <0.001) owing to greater rates of mortality (11.2% vs 6.7%, p = 0.08), reinfarction (11.6% vs 7.1%, p = 0.09), stroke (5.1% vs 1.8%, p = 0.013), and ischemic target vessel revascularization (23.6% vs 12.9%, p = 0.005). The outcomes did not differ significantly as a function of the antithrombotic regimen. On multivariate analysis, previous CABG was an independent predictor of 3-year ischemic stroke (hazard ratio 3.57, 95% confidence interval 1.09 to 11.66). Intervention on the saphenous vein graft versus the native vessel predicted 3-year major adverse cardiovascular events (hazard ratio 2.69, 95% confidence interval 1.17 to 6.19). In the HORIZONS-AMI trial, previous CABG was associated with a delay to mechanical reperfusion and lower rates of percutaneous coronary intervention and patency of the infarct related vessel along with worse clinical outcomes.

Adverse event rates following primary PCI for STEMI at US and non-US hospitals: three-year analysis from the HORIZONS-AMI trial.

AIMS: To examine outcomes in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) at US sites versus sites outside the US (OUS). METHODS AND RESULTS: In the HORIZONS-AMI trial 3,602 STEMI patients in 11 countries were randomised to primary PCI with bivalirudin versus heparin + glycoprotein IIb/IIIa inhibitors. US patients (n=814) had more diabetes, prior infarction, prior bypass surgery, and renal insufficiency. OUS patients (n=2,788) had longer door-to-balloon times, more radial access, fewer bypass surgeries, and were discharged more often on beta-blockers and statins. At three years US patients had higher mortality (9.7% vs. 6.0%, p=0.0003), reinfarction (10.2% vs. 6.4%, p=0.001), major adverse cardiac events (MACE; 28.2% vs. 20.1%, p<0.0001), major bleeding (16.9% vs. 6.4%, p<0.0001) and net adverse clinical events (NACE; 36.6% vs. 23.8%, p<0.0001), which persisted after adjusting for baseline risk. CONCLUSIONS: In the HORIZONS-AMI trial, STEMI patients undergoing primary PCI at US versus OUS sites had higher rates of adverse events, which persisted after adjusting for baseline risk. The reasons for these differences are not clear but may be due to unmeasured confounders, different thresholds for event reporting, or valid differences in systems of care and treatments.

Are adverse events following an invasive strategy in patients with non-ST-segment elevation acute coronary syndromes more frequent at US sites versus non-US sites? Analysis from the ACUITY trial.

OBJECTIVE: To compare outcomes between US and non-US (OUS) sites in patients with non ST-elevation acute coronary syndromes (NSTEACS) and to evaluate potential reasons for differences in outcomes. BACKGROUND: There are little data comparing outcomes at US versus OUS sites in patients with NSTEACS managed with an invasive strategy. METHODS: The ACUITY trial randomized 13,819 patients with NSTEACS in 17 countries to an invasive approach with one of three strategies: (1) heparin plus glycoprotein platelet inhibitors (GPI), (2) bivalirudin plus GPI, or (3) bivalirudin alone. RESULTS: US patients were more often female, were younger, heavier, and had more diabetes, prior myocardial infarction (MI), and prior bypass surgery. US patients were less often treated with percutaneous coronary intervention but had more frequent drug-eluting stent use. US patients had lower mortality and higher MI rates at 30 days and 1 year and higher composite ischemic outcome at 30 days. After adjusting for differences in baseline variables, US patients had higher rates of MI and composite ischemic outcome at 30 days and higher rates of MI at 1 year {HR [95% confidence interval (CI)] = 1.36 [1.18-1.56], P < 0.0001} with no differences in mortality. There were no differences in treatment effects comparing bivalirudin with the other strategies between US and OUS sites. CONCLUSIONS: US versus OUS patients with NSTEACS had higher adjusted rates of MI and ischemia. The reasons for these differences are not clear but may be due to unmeasured confounders, different thresholds for event reporting, or valid differences in systems of care which may impact outcomes.

Relationship between biomarkers and subsequent bleeding risk in ST-segment elevation myocardial infarction patients treated with paclitaxel-eluting stents: a HORIZONS-AMI substudy.

Major bleeding complications in STEMI patients result in significant mortality, morbidity and healthcare cost. Identification of patients at increased risk of bleeding is therefore essential. New biomarkers might be of incremental value to identify patients at risk for bleeding after primary PCI. A total of 26 biomarkers were measured at enrolment and analyzed at a central core laboratory in 464 STEMI patients in the HORIZONS-AMI trial. We investigated the relationship between tertiles of biomarker and in hospital non-CABG major bleeding. In hospital non-CABG major bleeding occurred in 3.7% of patients (n = 17). Increasing levels of cystatin C and D-dimer at admission were associated with higher rates of in hospital major bleeding. After adjustment for a risk score for bleeding, the odds ratio for in hospital major bleeding was 3.13 for cystatin C > 2.04 mg/L (p = 0.046) and 3.28 for ESAM > 34 ng/mL (p = 0.037). In this exploratory analysis of the HORIZONS-AMI biomarker substudy, high cystatin C and ESAM levels were associated with a higher risk of major bleeding. Larger studies are warranted to confirm the prognostic value of cystatin C and ESAM for major bleeding in STEMI patients.

Long-term prognosis of patients presenting with ST-segment elevation myocardial infarction with no significant coronary artery disease (from the HORIZONS-AMI trial).

The clinical features and prognosis of patients with ST-segment elevation myocardial infarction (STEMI) and no significant coronary artery disease (CAD) have not been well studied. We examined the outcomes of patients with STEMI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial according to the presence or absence of significant CAD. "No-CAD" was defined by the absence of any lesion with a diameter stenosis of ≥30% on quantitative coronary angiography of the baseline coronary angiogram. Of 3,602 patients, 127 (3.5%) had no-CAD. Of these, 86 (67.7%) had angiographically normal coronary arteries, and 41 (32.3%) had mild disease (diameter stenosis <30%). Eight patients had previously been treated with coronary artery bypass grafting. Compared to patients with CAD, patients with no-CAD were younger, had a lower body mass index, were more frequently black, had a lower prevalence of smoking and previous angina, and had a greater left ventricular ejection fraction. Cardiac enzymes were elevated in fewer patients with no-CAD than in those with CAD (63.2% vs 98.7%, p <0.001). At 3 years of follow-up, the patients with no-CAD versus CAD had lower rates of major adverse cardiovascular events (7.7% vs 22.2%, p = 0.002), net adverse clinical events (major adverse cardiovascular events or major bleeding not related to coronary artery bypass grafting, 12.5% vs 26.9%, p = 0.005), and postprocedure coronary revascularization (0% vs 19.5%, p <0.001). The differences in the rates of death or reinfarction, stroke, and major bleeding were not statistically significant. In conclusion, 3.5% of patients with STEMI had no significant CAD. The 3-year prognosis for these patients was favorable compared to that of patients with STEMI and with obstructive CAD.

Incidence and predictors of coronary stent thrombosis: evidence from an international collaborative meta-analysis including 30 studies, 221,066 patients, and 4276 thromboses.

BACKGROUND: Stent thrombosis remains among the most feared complications of percutaneous coronary intervention (PCI) with stenting. However, data on its incidence and predictors are sparse and conflicting. We thus aimed to perform a collaborative systematic review on incidence and predictors of stent thrombosis. METHODS: PubMed was systematically searched for eligible studies from the drug-eluting stent (DES) era (1/2002-12/2010). Studies were selected if including ≥ 2000 patients undergoing stenting or reporting on ≥ 25 thromboses. Study features, patient characteristics, and incidence of stent thrombosis were abstracted and pooled, when appropriate, with random-effect methods (point estimate [95% confidence intervals]), and consistency of predictors was formally appraised. RESULTS: A total of 30 studies were identified (221,066 patients, 4276 thromboses), with DES used in 87%. After a median of 22 months, definite, probable, or possible stent thrombosis had occurred in 2.4% (2.0%; 2.9%), with acute in 0.4% (0.2%; 0.6%), subacute in 1.1% (1.0%; 1.3%), late in 0.5% (0.4%; 0.6%), and very late in 0.6% (0.4%; 0.8%). Similar figures were computed for studies reporting only on DES. From a total of 47 candidate variables, definite/probable stent thrombosis was more commonly and consistently predicted by early antiplatelet therapy discontinuation, extent of coronary disease, and stent number/length, with acute coronary syndrome at admission, diabetes, smoking status, and bifurcation/ostial disease also proving frequent predictors, but less consistently. CONCLUSIONS: Despite numerous possible risk factors, the most common and consistent predictors of stent thrombosis are early antiplatelet therapy discontinuation, extent of coronary disease, and stent number/length.

Relationship between biomarkers and subsequent clinical and angiographic restenosis after paclitaxel-eluting stents for treatment of STEMI: a HORIZONS-AMI substudy.

Drug-eluting stents (DES) reduce the incidence of in-stent restenosis (ISR) after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). Whether the use of biomarkers might be of utility to identify patients who remain at risk for DES ISR after primary PCI has never been examined. A total of 26 biomarkers were measured at enrollment and 30 days and analyzed at a central core laboratory in 501 STEMI patients from the HORIZONS-AMI trial. All patients underwent primary PCI with the TAXUS paclitaxel-eluting stent (PES), were scheduled for routine angiographic follow-up at 13 months, and were followed for 3 years. Mean in-stent late-loss was 0.28 ± 0.57 mm, and target lesion revascularization (TLR) at 3 years occurred in 9.1 % of patients. Low levels of interleukin-6 (IL-6) and placental growth factor (PLGF) at admission were associated with both higher in-stent late loss and ischemia-driven TLR. Additionally, low admission levels of cardiotrophin-1 (CT-1) were associated with higher rates of ischemia-driven TLR. At 30-day follow-up lower values of IL-1ra (IL-1ra), matrix metalloproteinase 9 (MMP9), and myeloperoxidase (MPO), and a decline relative to admission in IL-1ra, monocyte chemotactic protein-1 (MCP-1), and MMP9 were associated with higher in-stent late loss. Low values of IL-6 at 30 days were also associated with ischemia-driven TLR. After multivariate adjustment, only MPO at 30 days and a decline of MCP-1 between admission and 30 days were associated with in-stent late loss, and only CT-1 was associated with TLR. MPO at 30 days and a decline of MCP-1 between admission and 30 days were independently associated with in-stent late loss, and CT-1 was associated with TLR. Additional studies to confirm and validate the utility of these biomarkers are warranted.