Frequency and Patterns of Brain Infarction in Patients With Embolic Stroke of Undetermined Source: NAVIGATE ESUS Trial.

BACKGROUND AND PURPOSE: The spectrum of brain infarction in patients with embolic stroke of undetermined source (ESUS) has not been well characterized. Our objective was to define the frequency and pattern of brain infarcts detected by magnetic resonance imaging (MRI) among patients with recent ESUS participating in a clinical trial. METHODS: In the NAVIGATE ESUS trial (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source), an MRI substudy was carried out at 87 sites in 15 countries. Participants underwent an MRI using a specified protocol near randomization. Images were interpreted centrally by those unaware of clinical characteristics. RESULTS: Among the 918 substudy cohort participants, the mean age was 67 years and 60% were men with a median (interquartile range) of 64 (26-115) days between the qualifying ischemic stroke and MRI. On MRI, 855 (93%) had recent or chronic brain infarcts that were multiple in 646 (70%) and involved multiple arterial territories in 62% (401/646). Multiple brain infarcts were present in 68% (510/755) of those without a history of stroke or transient ischemic attack before the qualifying ESUS. Prior stroke/transient ischemic attack (P<0.001), modified Rankin Scale score >0 (P<0.001), and current tobacco use (P=0.01) were associated with multiple infarcts. Topographically, large and/or cortical infarcts were present in 89% (757/855) of patients with infarcts, while in 11% (98/855) infarcts were exclusively small and subcortical. Among those with multiple large and/or cortical infarcts, 57% (251/437) had one or more involving a different vascular territory from the qualifying ESUS. CONCLUSIONS: Most patients with ESUS, including those without prior clinical stroke or transient ischemic attack, had multiple large and/or cortical brain infarcts detected by MRI, reflecting a substantial burden of clinical stroke and covert brain infarction. Infarcts most frequently involved multiple vascular territories. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

Potential Embolic Sources and Outcomes in Embolic Stroke of Undetermined Source in the NAVIGATE-ESUS Trial.

Background and Purpose- Emboli in embolic stroke of undetermined source (ESUS) may originate from various potential embolic sources (PES), some of which may respond better to anticoagulation, whereas others to antiplatelets. We analyzed whether rivaroxaban is associated with reduction of recurrent stroke compared with aspirin in patients with ESUS across different PES and by number of PES. Methods- We assessed the presence/absence of each PES (atrial cardiopathy, atrial fibrillation, arterial atherosclerosis, left ventricular dysfunction, cardiac valvulopathy, patent foramen ovale, cancer) in NAVIGATE-ESUS (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source) participants. Prevalence of each PES, as well as treatment effect and risk of event for each PES were determined. Results by number of PES were also determined. The outcomes were ischemic stroke, all-cause mortality, cardiovascular mortality, and myocardial infarction. Results- In 7213 patients (38% women, mean age 67years) followed for a median of 11 months, the 3 most prevalent PES were atrial cardiopathy (37%), left ventricular disease (36%), and arterial atherosclerosis (29%). Forty-one percent of all patients had multiple PES, with 15% having ≥3 PES. None or a single PES was present in 23% and 36%, respectively. Recurrent ischemic stroke risk was similar for rivaroxaban- and aspirin-assigned patients for each PES, except for those with cardiac valvular disease which was marginally higher in rivaroxaban-assigned patients (hazard ratio, 1.8 [95% CI, 1.0-3.0]). All-cause mortality risks were similar across treatment groups for each PES while too few myocardial infarctions and cardiovascular deaths occurred for meaningful assessment. Increasing number of PES was not associated with increased stroke recurrence nor all-cause mortality, and outcomes did not vary between rivaroxaban- and aspirin-assigned patients by number of PES. Conclusions- A large proportion of patients with ESUS had multiple PES which could explain the neutral results of NAVIGATE-ESUS. Recurrence rates between rivaroxaban- and aspirin-assigned patients were similar across the spectrum of PES. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

Atrial Cardiopathy and Nonstenosing Large Artery Plaque in Patients With Embolic Stroke of Undetermined Source.

Background and Purpose- Atrial cardiopathy and atherosclerotic plaque are two potential mechanisms underlying embolic strokes of undetermined source (ESUS). The relationship between these two mechanisms among ESUS patients remains unclear. A better understanding of their association may inform targeted secondary prevention strategies. Methods- We examined the association between atrial cardiopathy and atherosclerotic plaque in the NAVIGATE ESUS trial (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source), which enrolled 7213 patients with recent ESUS during 2014 to 2017. For this analysis, we included patients with data on left atrial dimension, location of brain infarction, and cervical large artery plaque. The variables of primary interest were left atrial diameter and cervical plaque ipsilateral to brain infarction. Secondary markers of atrial cardiopathy were premature atrial contractions on Holter monitoring and newly diagnosed atrial fibrillation. For descriptive purposes, left atrial enlargement was defined as ≥4.7 cm. Multivariable logistic regression was used to examine the association between atrial cardiopathy markers and ipsilateral plaque after adjustment for age, sex, body mass index, hypertension, diabetes mellitus, current smoking, and hyperlipidemia. Results- Among 3983 eligible patients, 235 (5.9%) had left atrial enlargement, 939 (23.6%) had ipsilateral plaque, and 94 (2.4%) had both. Shared risk factors for left atrial enlargement and ipsilateral plaque were male sex, white race, hypertension, tobacco use, and coronary artery disease. Despite shared risk factors, increasing left atrial dimension was not associated with ipsilateral plaque after adjustment for covariates (odds ratio per cm, 1.1 [95% CI, 1.0-1.2]; P=0.08). We found no consistent associations between secondary markers of atrial cardiopathy and ipsilateral plaque. Conclusions- In a large population of patients with ESUS, we did not observe a notable association between atrial cardiopathy and atherosclerotic plaque, and few patients had both conditions. These findings suggest that atrial cardiopathy and atherosclerotic plaque may be distinct, nonoverlapping risk factors for stroke among ESUS patients.

Predictors of Recurrent Ischemic Stroke in Patients with Embolic Strokes of Undetermined Source and Effects of Rivaroxaban Versus Aspirin According to Risk Status: The NAVIGATE ESUS Trial.

BACKGROUND: Embolic stroke of undetermined source (ESUS) identifies patients with cryptogenic ischemic stroke presumed due to embolism from several unidentified sources. Among patients with recent ESUS, we sought to determine independent predictors of recurrent ischemic stroke during treatment with aspirin or rivaroxaban and to assess the relative effects of these treatments according to risk. METHODS: Exploratory analyses of 7213 participants in the NAVIGATE ESUS international trial who were randomized to aspirin 100 mg/day or rivaroxaban 15 mg/day and followed for a median of 11 months, during which time there were 309 first recurrent ischemic strokes (4.6% per year). Baseline features were correlated with recurrent stroke by multivariate analysis. RESULTS: The 7 independent predictors of recurrent stroke were stroke or transient ischemic attack (TIA) prior to the qualifying stroke (hazard ratio [HR] 2.03 95% confidence internal [CI] 1.58-2.60), current tobacco user (HR 1.62, 95% CI 1.24-2.12), age (HR 1.02 per year increase, 95%CI 1.01-1.03), diabetes (HR 1.28, 95% CI 1.01-1.64), multiple acute infarcts on neuroimaging (HR 1.49, 95% CI 1.09-2.02), aspirin use prior to qualifying stroke (HR 1.34, 95% CI 1.02-1.70), and time from qualifying stroke to randomization (HR .98, 95% CI .97-.99). The rate of recurrent stroke rate was 2.6% per year for participants without any of these risk factors, and increased by an average of 45% for each independent predictor (P < .001). There were no significant interactions between treatment effects and independent stroke predictors or stroke risk status. CONCLUSIONS: In this large cohort of ESUS patients, several features including prior stroke or TIA, advanced age, current tobacco user, multiple acute infarcts on neuroimaging, and diabetes independently identified those with an increased risk of ischemic stroke recurrence. The relative effects of rivaroxaban and aspirin were similar across the spectrum of independent stroke predictors and recurrent stroke risk status.

P2Y12 Inhibitor Switching in Response to Routine Notification of CYP2C19 Clopidogrel Metabolizer Status Following Acute Coronary Syndromes.

Importance: Physician behavior in response to knowledge of a patient's CYP2C19 clopidogrel metabolizer status is unknown. Objective: To investigate the association of mandatory reporting of CYP2C19 pharmacogenomic testing, provided to investigators with no direct recommendations on how to use these results, with changes in P2Y12 inhibitor use, particularly clopidogrel, in the Randomized Trial to Compare the Safety of Rivaroxaban vs Aspirin in Addition to Either Clopidogrel or Ticagrelor in Acute Coronary Syndrome (GEMINI-ACS-1) clinical trial. Design, Setting, and Participants: The GEMINI-ACS-1 trial compared rivaroxaban, 2.5 mg twice daily, with aspirin, 100 mg daily, plus open-label clopidogrel or ticagrelor (provided), in patients with recent acute coronary syndromes (ACS). The trial included 371 clinical centers in 21 countries and 3037 patients with ACS. Data were analyzed between May 2017 and February 2019. Interventions: Investigators were required to prestipulate their planned response to CYP2C19 metabolizer status. In response to a regulatory mandate, results for all patients were reported to investigators approximately 1 week after randomization. Main Outcomes and Measures: Reasons for switching P2Y12 inhibitors and occurrence of bleeding and ischemic events were collected. Results: Of 3037 patients enrolled (mean [SD] age, 62.8 [9.0] years; 2275 men [74.9%], and 2824 white race/ethnicity [93.0%]), investigators initially treated 1704 (56.1%) with ticagrelor and 1333 (43.9%) with clopidogrel. Investigators prestipulated that they would use CYP2C19 metabolizer status to change P2Y12 inhibitor in 48.5% of genotyped clopidogrel-treated patients (n = 642 of 1324) and 5.5% of genotyped ticagrelor-treated patients (n = 93 of 1692). P2Y12 inhibitor switching for any reason occurred in 197 patients and was more common in patients treated with ticagrelor (146 of 1704 [8.6%]) compared with clopidogrel (51 of 1333 [3.8%]). Of patients initially treated with ticagrelor, only 1 (0.1% overall; 0.7% of all who switched) was switched based on CYP2C19 status. Of patients initially treated with clopidogrel, 23 (1.7% overall,;45.1% of all who switched) were switched owing to metabolizer status. Of 48 patients (3.6%) with reduced metabolizer status treated initially with clopidogrel, 15 (31.3%) were switched based on metabolizer status, including 48.1% (13 of 27) in which switching was prestipulated. Conclusions and Relevance: Physicians were evenly split on how to respond to knowledge of CYP2C19 metabolizer status in clopidogrel-treated patients. Mandatory provision of this information rarely prompted P2Y12 inhibitor switching overall, including a minority of patients with reduced metabolizer status. These findings highlight the clinical equipoise among physicians regarding use of this information and the reluctance to use information from routine genotyping in the absence of definitive clinical trial data demonstrating the efficacy of this approach. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02293395.

Characterization of Patients with Embolic Strokes of Undetermined Source in the NAVIGATE ESUS Randomized Trial.

BACKGROUND: The New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial vs. ASA to Prevent Embolism in Embolic Stroke of Undetermined Source (NAVIGATE-ESUS) trial is a randomized phase-III trial comparing rivaroxaban versus aspirin in patients with recent ESUS. AIMS: We aimed to describe the baseline characteristics of this large ESUS cohort to explore relationships among key subgroups. METHODS: We enrolled 7213 patients at 459 sites in 31 countries. Prespecified subgroups for primary safety and efficacy analyses included age, sex, race, global region, stroke or transient ischemic attack prior to qualifying event, time to randomization, hypertension, and diabetes mellitus. RESULTS: Mean age was 66.9 ± 9.8 years; 24% were under 60 years. Older patients had more hypertension, coronary disease, and cancer. Strokes in older subjects were more frequently cortical and accompanied by radiographic evidence of prior infarction. Women comprised 38% of participants and were older than men. Patients from East Asia were oldest whereas those from Latin America were youngest. Patients in the Americas more frequently were on aspirin prior to the qualifying stroke. Acute cortical infarction was more common in the United States, Canada, and Western Europe, whereas prior radiographic infarctions were most common in East Asia. Approximately forty-five percent of subjects were enrolled within 30 days of the qualifying stroke, with earliest enrollments in Asia and Eastern Europe. CONCLUSIONS: NAVIGATE-ESUS is the largest randomized trial comparing antithrombotic strategies for secondary stroke prevention in patients with ESUS. The study population encompasses a broad array of patients across multiple continents and these subgroups provide ample opportunities for future research.

Clinically significant bleeding with low-dose rivaroxaban versus aspirin, in addition to P2Y12 inhibition, in acute coronary syndromes (GEMINI-ACS-1): a double-blind, multicentre, randomised trial.

BACKGROUND: Dual antiplatelet therapy (DAPT), aspirin plus a P2Y12 inhibitor, is the standard antithrombotic treatment following acute coronary syndromes. The factor Xa inhibitor rivaroxaban reduced mortality and ischaemic events when added to DAPT, but caused increased bleeding. The safety of a dual pathway antithrombotic therapy approach combining low-dose rivaroxaban (in place of aspirin) with a P2Y12 inhibitor has not been assesssed in acute coronary syndromes. We aimed to assess rivaroxaban 2·5 mg twice daily versus aspirin 100 mg daily, in addition to clopidogrel or ticagrelor (chosen at investigator discretion before randomisation), for patients with acute coronary syndromes started within 10 days after presentation and continued for 6-12 months. METHODS: In this double-blind, multicentre, randomised trial (GEMINI-ACS-1) done at 371 clinical centres in 21 countries, eligible patients were older than 18 years with unstable angina, non-ST segment elevation myocardial infarction (NSTEMI) or ST segment elevation myocardial infarction (STEMI), with positive cardiac biomarkers and either ischaemic electrocardiographic changes or an atherosclerotic culprit lesion identified during angiography. Participants were randomly assigned (1:1) within 10 days after admission for the index acute coronary syndromes event to either aspirin or rivaroxaban based on a computer-generated randomisation schedule. Randomisation was balanced by using randomly permuted blocks with size of four and was stratified based on the background P2Y12 inhibitor (clopidogrel or ticagrelor) intended to be used at the time of randomisation. Investigators and patients were masked to treatment assignment. Patients received a minimum of 180 days of double-blind treatment with rivaroxaban 2·5 mg twice daily or aspirin 100 mg daily. The choice of clopidogrel or ticagrelor during trial conduct was not randomised and was based on investigator preference. The primary endpoint was thrombolysis in myocardial infarction (TIMI) clinically significant bleeding not related to coronary artery bypass grafting (CABG; major, minor, or requiring medical attention) up to day 390. Primary analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT02293395. FINDINGS: Between April 22, 2015, and Oct 14, 2016, 3037 patients with acute coronary syndromes were randomly assigned; 1518 to receive aspirin and 1519 to receive rivaroxaban. 1704 patients (56%) were in the ticagrelor and 1333 (44%) in the clopidogrel strata. Median duration of treatment was 291 days (IQR 239-354). TIMI non-CABG clinically significant bleeding was similar with rivaroxaban versus aspirin therapy (total 154 patients [5%]; 80 participants [5%] of 1519 vs 74 participants [5%] of 1518; HR 1·09 [95% CI 0·80-1·50]; p=0·5840). INTERPRETATION: A dual pathway antithrombotic therapy approach combining low-dose rivaroxaban with a P2Y12 inhibitor for the treatment of patients with acute coronary syndromes had similar risk of clinically significant bleeding as aspirin and a P2Y12 inhibitor. A larger, adequately powered trial would be required to definitively assess the efficacy and safety of this approach. FUNDING: Janssen Research & Development and Bayer AG.

A randomized trial to compare the safety of rivaroxaban vs aspirin in addition to either clopidogrel or ticagrelor in acute coronary syndrome: The design of the GEMINI-ACS-1 phase II study.

Dual antiplatelet therapy (DAPT), the combination of aspirin and a P2Y12 inhibitor, given for 12 months remains the standard of care after presentation with acute coronary syndrome (ACS) because it has been shown to be associated with a significant reduction in ischemic events compared with aspirin monotherapy. The factor Xa inhibitor rivaroxaban was shown to be associated with a significant reduction in the composite of cardiovascular death, myocardial infarction, and stroke, and resulted in a nominal reduction in cardiovascular death, when added to background DAPT in the ATLAS ACS 2-TIMI 51 trial; however, there was excessive bleeding with this "triple-therapy" approach. The combination of rivaroxaban with P2Y12 inhibition in a "dual-pathway" approach may be an effective therapeutic regimen for the treatment of ACS, given the known importance of P2Y12 inhibition after stenting and intriguing data that the combination of an anticoagulant with clopidogrel after stenting in patients with atrial fibrillation appears an attractive option to this patient population. GEMINI-ACS-1 is a prospective, randomized, double-dummy, double-blind, active-controlled trial that will assess the safety of dual antithrombotic therapy (rivaroxaban [2.5 mg twice daily] + P2Y12 inhibitor) as compared with DAPT (aspirin [100 mg] + P2Y12 inhibitor) within 10 days of an ACS event in 3,000 patients. Patients will be randomized in a 1:1 ratio stratified by intended P2Y12 inhibitor use (clopidogrel 75 mg daily or ticagrelor 90 mg twice daily), with 1500 patients expected in each P2Y12 inhibitor strata. The primary end point is Thrombolysis in Myocardial Infarction clinically significant bleeding (major, minor, or requiring medical attention). The exploratory efficacy determination will be a composite of cardiovascular death, myocardial infarction, ischemic stroke, and stent thrombosis. GEMINI-ACS-1 will assess the safety and feasibility of dual antithrombotic therapy with rivaroxaban and a P2Y12 inhibitor compared with conventional DAPT for the treatment for patients with recent ACS.

Fasting triglycerides predict recurrent ischemic events in patients with acute coronary syndrome treated with statins.

BACKGROUND: Most patients with acute coronary syndrome (ACS) are treated with statins, which reduce atherogenic triglyceride-rich lipoproteins. It is uncertain whether triglycerides predict risk after ACS on a background of statin treatment. OBJECTIVES: This study examined the relationship of fasting triglyceride levels to outcomes after ACS in patients treated with statins. METHODS: Long-term and short-term relationships of triglycerides to risk after ACS were examined in the dal-OUTCOMES trial and atorvastatin arm of the MIRACL (Myocardial Ischemia Reduction with Acute Cholesterol Lowering) trial, respectively. Analysis of dal-OUTCOMES included 15,817 patients (97% statin-treated) randomly assigned 4 to 12 weeks after ACS to treatment with dalcetrapib (a cholesteryl ester transfer protein inhibitor) or placebo and followed for a median 31 months. Analysis of MIRACL included 1,501 patients treated with atorvastatin 80 mg daily beginning 1 to 4 days after ACS and followed for 16 weeks. Fasting triglycerides at initial random assignment were related to risk of coronary heart disease death, nonfatal myocardial infarction, stroke, and unstable angina in models adjusted for age, sex, hypertension, smoking, diabetes, high-density lipoprotein cholesterol, and body mass index. RESULTS: Fasting triglyceride levels were associated with both long-term and short-term risk after ACS. In dal-OUTCOMES, long-term risk increased across quintiles of baseline triglycerides (p<0.001). The hazard ratio in the highest/lowest quintile (>175/≤80 mg/dl) was 1.61 (95% confidence interval: 1.34 to 1.94). There was no interaction of triglycerides and treatment assignment on the primary outcome. In the atorvastatin group of MIRACL, short-term risk increased across tertiles of baseline triglycerides (p=0.03), with a hazard ratio of 1.50 [corrected] (95% confidence interval: 1.05 to 2.15) in highest/lowest tertiles (>195/≤135 mg/dl). The relationship of triglycerides to risk was independent of low-density lipoprotein cholesterol in both studies. CONCLUSIONS: Among patients with ACS treated effectively with statins, fasting triglycerides predict long-term and short-term cardiovascular risk. Triglyceride-rich lipoproteins may be an important additional target for therapy. (A Study of RO4607381 in Stable Coronary Heart Disease Patients With Recent Acute Coronary Syndrome; NCT00658515).