Effect of Short Procedural Duration With Bivalirudin on Increased Risk of Acute Stent Thrombosis in Patients With STEMI: A Secondary Analysis of the HORIZONS-AMI Randomized Clinical Trial

Importance

Bivalirudin has been associated with reduced bleeding and mortality during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). However, increased rates of acute stent thrombosis (AST) have been noted when bivalirudin is discontinued at the end of the procedure, which is perhaps related to this medication's short half-life.

Objectives

To evaluate the clinical effect of procedure duration on AST when either bivalirudin or heparin plus glycoprotein IIb/IIIa receptor inhibitor (GPI) is used.

Design, Setting, and Participants

An ad hoc analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) clinical trial was performed between March 1, 2015, and April 30, 2016, on patients who underwent primary percutaneous coronary intervention with stents and were randomized 1:1 to bivalirudin or heparin plus GPI. Defined as the difference between the patient's arrival at the catheterization laboratory and the patient's final angiogram. Participants included 3602 patients with STEMI, aged 18 years or older, who were undergoing primary percutaneous coronary intervention and presenting less than 12 hours from symptom onset.

Main Outcomes and Measures

Clinical events committee-adjudicated definite AST (occurring ≤24 hours after percutaneous coronary intervention).

Results

Among patients included in this analysis, procedure time was identified in 1286 receiving bivalirudin and 1412 receiving heparin plus GPI. Shorter procedures were defined as the lowest quartile of duration (<45 minutes). Patients undergoing shorter procedures were younger and less likely to be hypertensive and smokers. Shorter procedures were less complicated with fewer stents implanted, less multivessel stenting, less thrombus, and less no-reflow. An increased risk of definite AST was associated with shorter than with longer procedures with bivalirudin (7 [2.1%] vs 7 [0.7%]; relative risk, 2.87; 95% CI, 1.01-8.17; P = .04) but not with heparin plus GPI (0 vs 3 [0.3%]; P = .30).

Conclusions and Relevance

Despite less procedural complexity, shorter primary percutaneous coronary intervention time was associated with an increased risk of AST in patients treated with bivalirudin but not patients treated with heparin plus GPI, possibly because of the rapid offset of bivalirudin's antithrombotic effect during a window of limited oral antiplatelet action.

Trial Registration

clinicaltrials.gov Identifier: NCT00433966.

Impact of Aspirin and Clopidogrel Hyporesponsiveness in Patients Treated With Drug-Eluting Stents: 2-Year Results of a Prospective, Multicenter Registry Study

OBJECTIVES

In this analysis of 2-year outcomes in the ADAPT-DES (Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents) study, the authors sought to examine the independent associations between platelet reactivity to both aspirin and clopidogrel and subsequent outcomes.

BACKGROUND

The relationship between platelet reactivity and long-term adverse events following implantation of drug-eluting stents (DES) has been incompletely characterized.

METHODS

The ADAPT-DES study was a multicenter registry of patients undergoing routine platelet function testing following percutaneous coronary intervention with DES. The primary study endpoint was definite or probable stent thrombosis (ST); other endpoints were all-cause mortality, myocardial infarction, and clinically relevant bleeding.

RESULTS

A total of 8,582 patients were enrolled between 2008 and 2010; 46.3% of patients were on dual antiplatelet therapy at 2 years without discontinuation. At 2 years, definite or probable ST occurred in 92 patients (1.07%). In patients treated with dual antiplatelet therapy continuously for 2 years, high platelet reactivity on clopidogrel was independently associated with definite or probable ST (adjusted hazard ratio [HR]: 2.16; 95% confidence interval [CI]: 1.27 to 3.67; p = 0.003), myocardial infarction (adjusted HR: 1.35; 95% CI: 1.05 to 1.74; p = 0.02), freedom from clinically relevant bleeding (adjusted HR: 0.74; 95% CI: 0.62 to 0.90; p = 0.002), and all-cause mortality (adjusted HR: 1.36; 95% CI: 1.01 to 1.85; p = 0.04). Between years 1 and 2, high platelet reactivity was not associated with the very late ST and in patients on aspirin monotherapy, aspirin hyporesponsiveness was not associated with adverse outcomes.

CONCLUSIONS

The present study confirms the strong relationship of high platelet reactivity on clopidogrel to 2-year ischemic and bleeding outcomes after DES. The majority of stent-related events occurred within the first year.

Relation Between Renal Function and Coronary Plaque Morphology (from the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Virtual Histology-Intravascular Ultrasound Substudy)

We sought to examine the relation between various degrees of renal function and coronary plaque morphology by grayscale and virtual histology intravascular ultrasound (IVUS). ADAPT-DES was a prospective, multicenter registry of 8,582 consecutive patients treated using coronary drug-eluting stents with a prespecified grayscale and virtual histology-IVUS substudy. A lesion-level analysis of study participants was performed by comparing IVUS parameters of culprit and nonculprit lesions across tertiles of estimated creatinine clearance (CrCl). Preintervention IVUS imaging of 762 patients identified 898 culprit and 752 nonculprit native coronary artery lesions. Patients in the lowest CrCl tertile were older, more often women, and more often presented with stable angina. Compared with the middle and upper tertiles, the lowest tertile was significantly associated with culprit lesion smaller mean external elastic membrane cross-sectional area (12.9 vs 14.2 mm³/mm vs 14.9 mm³/mm, p <0.0001), smaller mean lumen cross-sectional area (5.5 mm³/mm vs 5.8 mm³/mm vs 6.1 mm³/mm, p = 0.002), and more dense calcium volume (11.5% vs 10.2% vs 9.7%, p = 0.02). Similar trends were found in the nonculprit lesions. Plaque rupture was least common in patients in the lowest tertile. On multivariable analysis, independent predictors of greater dense calcium volume were lower CrCl, hyperlipidemia, female gender, and presentation without ST-segment elevation myocardial infarction. In conclusion, in the present large-scale IVUS study diminishing renal function was associated with increased coronary calcification and decreased coronary vessel and lumen sizes, with a graded response according to the reduction in CrCl. In addition, these patients were more likely to present with stable angina versus patients with normal renal function who were more likely to present with an acute coronary syndrome.

Comparison of Dabigatran and Warfarin in Patients With Atrial Fibrillation and Valvular Heart Disease

Background:

The RE-LY trial (Randomized Evaluation of Long-Term Anticoagulant Therapy) compared dabigatran 150 and 110 mg twice daily with warfarin in 18 113 patients with atrial fibrillation. Those with prosthetic heart valves, significant mitral stenosis, and valvular heart disease (VHD) requiring intervention were excluded. Others with VHD were included.

Methods:

This is a post hoc analysis of the RE-LY trial.

Results:

There were 3950 patients with any VHD: 3101 had mitral regurgitation, 1179 with tricuspid regurgitation, 817 had aortic regurgitation, 471 with aortic stenosis, and 193 with mild mitral stenosis. At baseline, patients with any VHD had more heart failure, coronary disease, renal impairment, and persistent atrial fibrillation. Patients with any VHD had higher rates of major bleeds (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.16–1.5) but similar stroke or systemic embolism event rates (HR, 1.09; 95% CI, 0.88–1.33). For patients receiving dabigatran 110 mg, major bleed rates were lower than for patients taking warfarin (HR, 0.73; 95% CI, 0.56–0.95 with VHD; HR, 0.84; 95% CI, 0.71–0.99 without VHD), and major bleed rates for dabigatran 150 mg were similar to those for warfarin in patients with VHD (HR, 0.82; 95% CI, 0.64–1.06) or without VHD (HR, 0.98; 95% CI, 0.83–1.15). For dabigatran 150 mg, stroke/systemic embolic event rates were lower compared with warfarin in those with VHD (HR, 0.59; 95% CI, 0.37–0.93) and those without VHD (HR, 0.67; 95% CI, 0.52–0.86), and stroke/systemic embolic event rates were similar for warfarin and dabigatran 110 mg regardless of the presence of VHD (HR, 0.97; 95% CI, 0.65–1.45; and HR, 0.88; 95% CI, 0.70–1.10). Intracranial bleeds and death rates for dabigatran 150 and 110 mg were lower compared with warfarin independently of the presence of VHD.

Conclusions:

The presence of any VHD did not influence the comparison of dabigatran with warfarin.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00262600.

Relation Between Platelet Count and Platelet Reactivity to Thrombotic and Bleeding Risk: From the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Study

Whether the association between platelet count (PC) and thrombotic and bleeding risk is independent of or varies by residual platelet reactivity to antiplatelet therapies is unclear. We sought to investigate the independent and combined effects of PC and platelet reactivity on thrombotic and bleeding risk after coronary artery implantation of drug-eluting stents (DES). Patients enrolled in the prospective, multicenter Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents study were stratified by PC tertiles. The study cohort comprised 8,402 patients. By linear regression analysis, lower PC was strongly and independently associated with higher platelet reactive units (PRUs) on clopidogrel. After multivariable adjustment (including PRU and aspirin reactive units), high, but not low, PC tertile was independently associated with higher risk of thrombotic complications, including spontaneous myocardial infarction and stent thrombosis. Although no independent association was observed between PC tertiles and hemorrhagic risk, both high and low PC tertiles were associated with increased risk for all-cause mortality. After stratification of PC tertiles by tertiles of PRUs, the crude risk of thrombotic complications was highest in patients in the high PC and high PRU tertiles. By multivariable adjustment, PRU increases were uniformly associated with higher risk of thrombotic events across PC tertiles, without evidence of interaction. In conclusion, higher PCs and higher PRUs act independently and synergistically in determining thrombotic risk. Alongside PRU, PCs could be a simple hematological parameter to consider for risk stratification and in tailoring duration and potency of pharmacologic platelet inhibition after DES implantation.

Coronary Thrombosis and Major Bleeding After PCI With Drug-Eluting Stents: Risk Scores From PARIS

BACKGROUND

Dual-antiplatelet therapy with aspirin and clopidogrel after percutaneous coronary intervention reduces the risk for coronary thrombotic events (CTEs) at the expense of increasing risk for major bleeding (MB). Metrics to accurately predict the occurrence of each respective event and inform clinical decision making are lacking.

OBJECTIVES

The aim of this study was to develop and validate separate models to predict risks for out-of-hospital thrombotic and bleeding events after percutaneous coronary intervention with drug-eluting stents.

METHODS

Using data from 4,190 patients treated with drug-eluting stents and enrolled in the PARIS (Patterns of Non-Adherence to Anti-Platelet Regimen in Stented Patients) registry, separate risk scores were developed to predict CTE (defined as the composite of stent thrombosis or myocardial infarction) and MB (defined as the occurrence of a Bleeding Academic Research Consortium type 3 or 5 bleed). External validation was performed in the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) registry.

RESULTS

Over 2 years, CTEs occurred in 151 patients (3.8%) and MB in 133 (3.3%). Independent predictors of CTEs included acute coronary syndrome, prior revascularization, diabetes mellitus, renal dysfunction, and current smoking. Independent predictors of MB included older age, body mass index, triple therapy at discharge, anemia, current smoking, and renal dysfunction. Each model displayed moderate levels of discrimination and adequate calibration.

CONCLUSIONS

Simple risk scores of baseline clinical variables may be useful to predict risks for ischemic and bleeding events after PCI with DES, thereby facilitating clinical decisions surrounding the optimal duration of DAPT. (Patterns of Non-Adherence to Anti-Platelet Regimen in Stented Patients [PARIS]; NCT00998127).

Impact of Hemoglobin A1c Levels on Residual Platelet Reactivity and Outcomes After Insertion of Coronary Drug-Eluting Stents (from the ADAPT-DES Study)

An increasing hemoglobin A1c (HbA1c) level portends an adverse cardiovascular prognosis; however, the association between glycemic control, platelet reactivity, and outcomes after percutaneous coronary intervention (PCI) with drug-eluting stents (DES) is unknown. We sought to investigate whether HbA1c levels are associated with high platelet reactivity (HPR) in patients loaded with clopidogrel and aspirin, thereby constituting an argument for intensified antiplatelet therapy in patients with poor glycemic control. In the prospective, multicenter Assessment of Dual Antiplatelet Therapy With Drug Eluting Stents registry, HbA1c levels were measured as clinically indicated in 1,145 of 8,582 patients, stratified by HbA1c <6.5% (n = 551, 48.12%), 6.5% to 8.5% (n = 423, 36.9%), and >8.5% (n = 171, 14.9%). HPR on clopidogrel and aspirin was defined after PCI as P2Y12 reaction units (PRU) >208 and aspirin reaction units >550, respectively. HPR on clopidogrel was frequent (48.3%), whereas HPR on aspirin was not (3.9%). Patients with HbA1c >8.5% were younger, more likely non-Caucasian, had a greater body mass index, and more insulin-treated diabetes and acute coronary syndromes. Proportions of PRU >208 (42.5%, 50.2%, and 62.3%, p <0.001) and rates of definite or probable stent thrombosis (ST; 0.9%, 2.7%, and 4.2%, p = 0.02) increased progressively with HbA1c groups. Clinically relevant bleeding was greatest in the intermediate HbA1c group (8.2% vs 13.1% vs 9.5%, p = 0.04). In adjusted models that included PRU, high HbA1c levels (>8.5) remained associated with ST (hazard ratio 3.92, 95% CI 1.29 to 12.66, p = 0.02) and cardiac death (hazard ratio 4.24, 95% CI 1.41 to 12.70) but not bleeding at 2-year follow-up. There was no association between aspirin reaction units >550 and HbA1c levels. In conclusion, in this large-scale study, HbA1c and HPR were positively associated, but the clinical effect on adverse outcome was driven by poor glycemic control, which predicted ST and cardiac death after PCI regardless of PRU levels, warranting efforts to improve glycemic control after DES implantation in patients with diabetes mellitus.

Hippocampal sclerosis after febrile status epilepticus: the FEBSTAT study

OBJECTIVE

Whether febrile status epilepticus (FSE) produces hippocampal sclerosis (HS) and temporal lobe epilepsy (TLE) has long been debated. Our objective is to determine whether FSE produces acute hippocampal injury that evolves to HS.

METHODS

FEBSTAT and 2 affiliated studies prospectively recruited 226 children aged 1 month to 6 years with FSE and controls with simple febrile seizures. All had acute magnetic resonance imaging (MRI), and follow-up MRI was obtained approximately 1 year later in the majority. Visual interpretation by 2 neuroradiologists informed only of subject age was augmented by hippocampal volumetrics, analysis of the intrahippocampal distribution of T2 signal, and apparent diffusion coefficients.

RESULTS

Hippocampal T2 hyperintensity, maximum in Sommer's sector, occurred acutely after FSE in 22 of 226 children in association with increased volume. Follow-up MRI obtained on 14 of the 22 with acute T2 hyperintensity showed HS in 10 and reduced hippocampal volume in 12. In contrast, follow-up of 116 children without acute hyperintensity showed abnormal T2 signal in only 1 (following another episode of FSE). Furthermore, compared to controls with simple febrile seizures, FSE subjects with normal acute MRI had abnormally low right to left hippocampal volume ratios, smaller hippocampi initially, and reduced hippocampal growth.

INTERPRETATION

Hippocampal T2 hyperintensity after FSE represents acute injury often evolving to a radiological appearance of HS after 1 year. Furthermore, impaired growth of normal-appearing hippocampi after FSE suggests subtle injury even in the absence of T2 hyperintensity. Longer follow-up is needed to determine the relationship of these findings to TLE.

Risk factors for febrile status epilepticus: a case-control study

OBJECTIVE

To identify risk factors for developing a first febrile status epilepticus (FSE) among children with a first febrile seizure (FS).

STUDY DESIGN

Cases were children with a first FS that was FSE drawn from the Consequences of Prolonged Febrile Seizures in Childhood and Columbia cohorts. Controls were children with a first simple FS and separately, children with a first complex FS that was not FSE. Identical questionnaires were administered to family members of the 3 cohorts. Magnetic resonance imaging protocol and readings were consistent across cohorts, and seizure phenomenology was assessed by the same physicians. Risk factors were analyzed using logistic regression.

RESULTS

Compared with children with simple FS, FSE was associated with younger age, lower temperature, longer duration (1-24 hours) of recognized temperature before FS, female sex, structural temporal lobe abnormalities, and first-degree family history of FS. Compared with children with other complex FS, FSE was associated with low temperature and longer duration (1-24 hours) of temperature recognition before FS. Risk factors for complex FS that was not FSE were similar in magnitude to those for FSE but only younger age was significant.

CONCLUSIONS

Among children with a first FS, FSE appears to be due to a combination of lower seizure threshold (younger age and lower temperatures) and impaired regulation of seizure duration. Clinicians evaluating FS should be aware of these factors as many episodes of FSE go unnoticed. Further work is needed to develop strategies to prevent FSE.

Design and phenomenology of the FEBSTAT study

PURPOSE

Febrile status epilepticus (FSE) has been associated with hippocampal injury and subsequent hippocampal sclerosis (HS) and temporal lobe epilepsy. The FEBSTAT study was designed to prospectively examine the association between prolonged febrile seizures and development of HS and associated temporal lobe epilepsy, one of the most controversial issues in epilepsy. We report on the baseline phenomenology of the final cohorts as well as detailed aims and methodology.

METHODS

The "Consequences of Prolonged Febrile Seizures in Childhood" (FEBSTAT) study is a prospective, multicenter study. Enrolled are children, aged 1 month to 6 years of age, presenting with a febrile seizure lasting 30 min or longer based on ambulance, emergency department, and hospital records, and parental interview. At baseline, procedures included a magnetic resonance imaging (MRI) study and electroencephalography (EEG) recording done within 72 h of FSE, and a detailed history and neurologic examination. Baseline development and behavior are assessed at 1 month. The baseline assessment is repeated, with age-appropriate developmental testing at 1 and 5 years after enrollment as well as at the development of epilepsy and 1 year after that. Telephone calls every 3 months document additional seizures. Two other groups of children are included: a "control" group consisting of children with a first febrile seizure ascertained at Columbia University and with almost identical baseline and 1-year follow-up examinations and a pilot cohort of FSE from Duke University.

KEY FINDINGS

The FEBSTAT cohort consists of 199 children with a median age at baseline of 16.0 months (interquartile range [IQR] 12.0-24.0) and a median duration of FSE of 70.0 min (IQR 47.0-110.0). Seizures were continuous in 57.3% and behaviorally intermittent (without recovery in between) in 31.2%; most were partial (2.0%) or secondary generalized (65.8%), and almost all (98.0%) culminated in a generalized tonic-clonic seizure. Of the 199 children, 86.4% had normal development and 20% had prior febrile seizures. In one third of cases, FSE was unrecognized in the emergency department. The Duke existing cohort consists of 23 children with a median age of FSE onset of 18.0 months (IQR 14.0-28.0) and median duration of FSE of 90.0 min (IQR 50.0-170.0). The Columbia control cohort consists of 159 children with a first febrile seizure who received almost the same workup as the FEBSTAT cohort at baseline and at 1 year. They were followed by telephone every 4 months for a median of 42 months. Among the control cohort, 64.2% had a first simple FS, 26.4% had a first complex FS that was not FSE, and 9.4% had FSE. Among the 15 with FSE, the median age at onset was 14.0 months (IQR 12.0-20.0) and the median duration of FSE was 43.0 min (IQR 35.0-75.0).

SIGNIFICANCE

The FEBSTAT study presents an opportunity to prospectively study the relationship between FSE and acute hippocampal damage, the development of mesial temporal sclerosis, epilepsy (particularly temporal lobe epilepsy), and impaired hippocampal function in a large cohort. It is hoped that this study may illuminate a major mystery in clinical epilepsy today, and permit the development of interventions designed to prevent the sequelae of FSE.