On Oral Anticoagulation Research Articles

LO40: Safe anticoagulation initiation for atrial fibrillation in the emergency department (the SAFE pathway)

Background: Atrial fibrillation (AF) is a risk for stroke. The Canadian Cardiovascular Society advises patients who are CHADS65 positive should be started on oral anticoagulation (OAC). Our local emergency department (ED) review showed that only 16% of CHADS65 positive patients were started on OAC and that 2% of our patients were diagnosed with stroke within 90 days. We implemented a new pathway for initiation of OAC in the ED (the SAFE pathway). Aim Statement: We report the effectiveness and safety of the SAFE pathway for initiation of OAC in patients treated for AF in the ED. Measures & Design: A multidisciplinary group of physicians and pharmacist developed the SAFE pathway for patients who are discharged home from the ED with a diagnosis of AF. Step 1: contraindications to OAC, Step 2: CHADS65 score, Step 3: OAC dosing if indicated. The pathway triggers referral to AF clinic, family physician letter and follow up call from the ED pharmacist. Patients are followed for 90 days by a structured medical record review and a structured telephone interview. We record persistence with OAC, stroke, TIA, systemic arterial embolism and major bleeding (ISTH criteria). Patient outcomes are fed back to the treating ED physician. Evaluation/ Results: The SAFE pathway was introduced in two EDs in June 2018. In total, 177 patients have had the pathway applied. The median age was 70 (interquartile range (IQR) 61-78), 48% male, median CHADS2 score 2 (IQR 0-2). 19/177 patients (11%) had a contraindication to initiating OAC. 122 patients (69%) had no contraindication to OAC and were CHADS65 positive. Of these 122 patients, 109 were given a prescription for OAC (96 the correct dose, 9 too high a dose and 4 too low a dose). 6 patients declined OAC and the physician did not want to start OAC for 7 patients. 73/122 were contacted by phone at 90 days, 15 could not be reached and 34 have not completed 90 days of follow up since their ED visit. Of the 73 who were reached by phone after 90 days, 65 were still taking an anticoagulant. To date, 1 patient who declined OAC (CHADS2 score of 2) had a stroke within 90 days and one patient prescribed OAC had a gastrointestinal bleed. Discussion/Impact: The SAFE pathway appears safe and effective although we continue to evaluate and improve the process.

GI Bleed? Don't Blame the Anticoagulant!

Gastrointestinal (GI) bleeding in patients with atrial fibrillation (AF) on oral anticoagulants (OAC) is not uncommon. In an industry-supported study,

Abstract WMP115: Hemorrhagic and Ischemic Stroke in Patients on Oral Anticoagulants for Nonvalvular Atrial Fibrillation With and Without Antiplatelet Therapy

Introduction: Antiplatelet (APT) therapy is challenging in patients on oral anticoagulants (OACs) for nonvalvular atrial fibrillation (NVAF) who have coronary artery diseases (CAD). Analyzing large scale registry of consecutive patients with NVAF should provide further guide for the safety and efficacy of combination therapy. Methods: We conducted historical multicenter registry at 71 centers in Japan between March 2017 and March 2018. The eligibility criteria were patients on OACs for NVAF on February 2013. There were no exclusion criteria and consecutive patients who met the eligibility criteria were registered. All patients were followed until March 2017. Co-primary endpoints were ischemic strokes including transient ischemic attack and hemorrhagic stroke including subarachnoid hemorrhage. The secondary endpoints were all-cause mortality, ischemic events (acute coronary syndrome, ischemic strokes, or systemic embolism), and major bleedings defined by ISTH and TIMI criteria. We estimated HRs of OACs and APT combination relative to OACs alone by Cox proportional hazard model adjusting for clinically relevant confounders. Results: Median age was 74 (range 20-101) years of 7826 registered patients. Sustained NVAF accounted for 49% and 73% of patients had history of CAD. Cumulative incidences of ischemic stroke and hemorrhagic stroke at 4 years were 3.8% and 0.91% in No-APT group while 5.3% and 1.2% in APT group, respectively (Figure). Adjusted HRs (95%CI) of APT group for ischemic stroke and hemorrhagic stroke were 1.03 (0.76-1.40) and 1.27 (0.67-2.4), respectively. Adjusted HRs (95%CI) for all-cause mortality, ischemic events, and major bleedings were 0.98 (0.79-1.23), 0.98 (0.74-1.32), and 1.25 (1.00-1.57), respectively. Conclusions: Adding APT in patients on AOC for NVAF did not decrease ischemic strokes and not increase hemorrhagic strokes. Because combination therapy might increase the risk of major bleedings, OAC alone should be prioritized.

Oral Anticoagulant Prescription Trends, Profile Use, and Determinants of Adherence in Patients with Atrial Fibrillation.

Data on oral anticoagulant (OAC) uptake and pattern of use are limited. Real-life data in patients with atrial fibrillation (AF) are important for understanding patient exposure. A cohort study of new OAC users was built to assess trends of drug use from 2011 to 2017, persistence rate, switching rate, adherence level, and predictors of adherence. We built a cohort using the Régie d'Assurance Maladie du Québec (RAMQ) and Med-Echo administrative databases of new adult OAC users within 1year following hospitalization with a diagnosis of AF. New users of OAC were defined as having no OAC claims in the year before cohort entry. We assessed trends of OAC use; persistence rate, defined as a gap between refills of no longer than two times the duration of the previous prescriptions; and adherence level, defined as the proportion of days covered (PDC) over a 1-year period following initiation. Predictors of nonadherence (PDC less than 80%) were analyzed using logistic regression models. The cohort consisted of 33,311 incident OAC users. Of total OAC claims, the proportions of warfarin claims decreased from 77.9% in 2011 to 12.7% in 2017, with direct oral anticoagulants (DOACs) accounting for 87.3% of claims, of which apixaban and rivaroxaban accounted for 60.1% and 23.4%, respectively, by the end of 2017. One year after OAC initiation, persistence rates ranged from 53% with warfarin to 77% with a high dose of apixaban. Approximately 75% of incident OAC users were considered "adherent" (PDC 80% or more), with a mean PDC of 95.6-98.1%, compared with "nonadherent," with a mean PDC varying between 43.1% and 50.7%. Older age, female sex, higher CHA2 DS2 -VASc score (to predict thromboembolic risk in AF), prior stroke, and treatment with chronic cardiovascular disease drugs were associated with high adherence levels. The clinical uptake of DOACs increased over time, accounting for 87.3% of prescriptions in 2017. In our study, 25% of new OAC users presented a low adherence level. Adherence to OACs remains a significant challenge in patients with AF.

P6536Implementation of a mass atrial fibrillation screening program in Canadian community practice

Abstract Background Atrial fibrillation is the most common arrhythmia seen in clinical practice, and is an important cause of stroke. In up to 10% of patients, stroke is the first clinical manifestation of undiagnosed atrial fibrillation (AF). Early detection of AF is therefore desirable, as it would provide an opportunity to initiate appropriate stroke prevention with anticoagulation. While European guidelines recommend screening for AF as part of routine care in patients with risk factors, the optimal modality has not yet been determined. Smartphone enabled single lead ECG devices have been shown to be highly accurate and could prove to be an effective point of care tool for uncovering AF in the community and may facilitate implementation of screening recommendations. Purpose We sought to describe the integration of a smartphone enabled single lead ECG device into the practice of selected Canadian community-based physicians and its impact on patient care. Methods Canadian community-based physicians were provided with a smartphone enabled single lead ECG device for a period of six months. Physicians were instructed to perform a single 30 second ECG recording in patients over the age of 65 who present for a regular follow-up visit. Patients with previous AF diagnosis were excluded. Outcomes related to screening, and stroke prevention-treatment initiation were prospectively ascertained and documented using a patient flow tracker. Results Among 612 physicians who were invited to participate in the program, 315 (51%) agreed to track and report the use of the device that was provided to them. During this program, 315 physicians screened a total of 15,538 patients. AF was detected 1103 patients (7.1%). The majority of patients with a positive screen underwent a subsequent 12-lead ECG confirmatory exam (79%). AF could not be confirmed in 277 patients (31.7% of patients undergoing 12-lead ECG). A total of 677 patients were initiated on oral anticoagulation (OAC), with 262 patients (24%) being initiated on OAC prior to ECG confirmation. Conclusion Undiagnosed AF is common in patients >65 years of age in community practice. The results of this program indicate that single lead mobile ECG devices can be integrated into routine point of care use for Canadian physicians and, can be a valuable tool to detect previously undiagnosed AF. While this approach identified a large number of undiagnosed AF patients eligible for OAC therapy, undertreatment with OAC remains a concern. Acknowledgement/Funding Bristol-Myers Squibb/Pfizer Alliance

P2794Real-world reasons and outcomes for 1-month versus longer dual antiplatelet therapy strategies with a polymer-free biolimus A9-coated stent: insights from the all-comers FREEDOM registry

Abstract Background The LEADERS FREE trial established the favourable clinical profile of a new polymer-free biolimus A9-eluting stent (PF-BES) in patients at high bleeding risk when used with a 1-month dual anti-platelet therapy (DAPT) strategy. Purpose This is the first study evaluating real-world reasons and outcomes for a 1-month versus longer DAPT strategies following PF-BES percutaneous coronary intervention (PCI). Methods FREEDOM is an all-comers registry including all patients who underwent PCI with at least one PF-BES at 10 sites, between January 2016 and July 2018. Patients were stratified according to DAPT strategy at discharge (1-month vs >1-month). Baseline features, reasons for PF-BES as reported by the treating physician, and outcomes were compared between groups. Primary outcomes were the 390-day estimates of a patient-oriented composite endpoint (POCE: death, myocardial infarction (MI) or target vessel revascularization) and of a device-oriented composite endpoint (DOCE: cardiac death, target vessel-MI or ischemia-driven target lesion revascularization). Incidence rates were adjusted for clinically relevant factors and outcome predictors. To avoid survival bias, landmark analyses starting from 1-month post-PCI were further carried. Results Following PF-BES PCI, 328 (40.3%) patients were discharged with 1-month DAPT and 485 (59.6%) patients with longer DAPT (median 12 months, IQR 6–12 months). Patients with hypertension or on oral anticoagulation (OAT) were more likely and patients with a previous or an index MI were less likely to be discharged on 1-month DAPT. Patients prescribed with 1-month DAPT were more likely to have had a PF-BES for a LEADERS FREE high bleeding risk criterium than those with longer DAPT (90.2% vs 69.9%, p=0.001). The same association was observed when the reason for PF-BES was a planned major surgery (13.1% vs 6.2%; p=0.001) or OAC to be continued after PCI (38.7% vs 16.5%, p<0.001). Conversely, patients with planned longer DAPT were more likely to have had a PF-BES following the operator preference (2.4% vs 15.5%, p<0.001) or for a reason other than a LEADERS FREE criterium or operator preference (5.2% vs 11.3%, p<0.001). No between-groups differences in the occurrence of the primary outcomes (1-month vs >1-month DAPT: POCE 11.9% vs 13.2%, p=0.747; adj-HR 1.29 [95% CI 0.78–2.10]; DOCE: 4.8% vs 8.1%, p=0.500; adj-HR 1.01 [95% CI 0.50–2.07]) and of bleedings (any: 11.3% vs 9.4%, p=0.472; adj-HR 0.87 [95% CI 0.51–1-50]; BARC 3–5: 4.2% vs 2.2%; p=0.108; adj-HR 1.50 [95% CI 0.58–3.87]) were observed. Landmark analyses showed similar results. Conclusions In a large contemporary all-comers registry, factors reflecting the operator-perceived patient high bleeding risk were the main drivers of a very-short DAPT strategy following PF-BES PCI. We found no interaction of DAPT duration with outcomes following PF-BES PCI, an observation warranting investigation in adequately powered randomised studies.

Use of pulsed electron avalanche knife (PEAK) PlasmaBlade™ in patients undergoing implantation of subcutaneous implantable cardioverter-defibrillator

IntroductionSurgical implantation of subcutaneous implantable cardioverter-defibrillators (S-ICD) requires preparation of a deeper and larger pocket. Infection and bleeding complications are reported, particularly in patients requiring antiplatelet therapy (APT) or being on oral anticoagulation (OAC), with rates up to 25%. The pulsed electron avalanche knife (PEAK) PlasmaBlade™ has been reported to reduce bleeding complications. The purpose of this study was to evaluate the safety and feasibility of a PEAK guided S-ICD implantation with respect to perioperative complications. Methods and resultsWe enrolled 36 consecutive patients (75% male; mean age 52.1 ± 14.4 years) undergoing S-ICD implantation. Periprocedural safety endpoints comprised major complications including pocket hematomas, wound infections, bleeding (BARC ≥2) or events requiring interventions. Patients were divided into three groups according to management of their anticoagulation: i.) APT, n = 15 (41.7%); ii.) OAC, n = 10 patients (27.8%); iii.) none (neither OAC nor APT), n = 11 (30.6%). Mean procedure duration was 33.1 ± 13.4 min. Mean length of hospital stay was 3.3 ± 2.1 days. Overall analysis showed no differences between the 3 groups with respect to major complications, major bleeding episodes or other procedural parameters, beside a trend towards more minor hematomas in the OAC group (OAC: 22.2% vs. APT: 11.4% vs. none: 9.1%; p = 0.15). ConclusionThe results of our pilot study suggest that intermuscular S-ICD implantation using PEAK is safe and potentially beneficial in patients receiving OAC or APT with respect to prevention of bleeding complications. These results support the rationale for large prospective controlled trials evaluating a beneficial effect of PEAK use in S-ICD implantation procedures.

Rivaroxaban Versus Warfarin in Patients With Nonvalvular Atrial Fibrillation and Severe Kidney Disease or Undergoing Hemodialysis

BackgroundPatients with nonvalvular atrial fibrillation with stage 4 or 5 chronic kidney disease or undergoing hemodialysis were excluded from phase III randomized trials of nonvitamin K antagonist oral anticoagulants (NOACs). We sought to evaluate the effectiveness and safety of rivaroxaban compared with warfarin in patients with nonvalvular atrial fibrillation and stage 4 or 5 chronic kidney disease or undergoing hemodialysis in routine practice. MethodsUsing MarketScan data from January 2012 to December 2017, we identified patients on oral anticoagulant (OAC) with naïve nonvalvular atrial fibrillation and stage 4 or 5 chronic kidney disease or undergoing hemodialysis and with ≥12 months of insurance coverage before OAC initiation. Differences in baseline covariates between the rivaroxaban and warfarin cohorts were adjusted using inverse probability-of-treatment weights based on propensity scores calculated using generalized boosted models and 10,000 regression trees (absolute standardized differences <0.1 achieved for all covariates after adjustment). Patients were followed until a stroke/systemic embolism or major bleeding event, OAC discontinuation/switch, insurance disenrollment, or end of data availability. Hazard ratios (HRs) and 95% confidence intervals (CIs) comparing the OAC cohorts were calculated using Cox regression. ResultsWe identified 1896 rivaroxaban (38.7% received a dose <20 mg/d) and 4848 warfarin users. Eighty-eight percent of included patients had stage 5 chronic kidney disease or were undergoing hemodialysis. Rivaroxaban did not significantly reduce stroke or systemic embolism (HR = 0.55, 95% CI = 0.27-1.10) or ischemic stroke (HR = 0.67, 95% CI = 0.30-1.50) alone, but it was associated with a significant 32% (95% CI = 1-53%) reduction in major bleeding risk compared with warfarin. ConclusionAmong patients with nonvalvular atrial fibrillation and stage 4 or 5 chronic kidney disease or undergoing hemodialysis, rivaroxaban appears associated with significantly less major bleeding compared to warfarin.

Hospitalization affects the anticoagulation patterns of patients with atrial fibrillation.

Scarce data are available on the effects of hospitalization on oral anticoagulation (OAC) patterns in patients with atrial fibrillation (AF). This study aimed to capture the evolving OAC patterns of patients with known non-valvular AF at high risk for stroke (CHA2DS2-Vasc score ≥ 2 for males and ≥ 3 for females) during hospitalization. A total of 561 eligible patients who were admitted to the cardiology ward of a tertiary hospital were studied. Pre- and post-hospitalization OAC patterns [vitamin-K antagonist (VKA), non-vitamin K oral anticoagulants (NOAC), no OAC], changes between these patterns (initiation, switch, discontinuation, no change) and the respective patient profiles and discharge diagnoses were assessed. During hospitalization, OAC administration increased from 73.1 to 86.6% of patients (p for trend < 0.001). NOAC use increased significantly (42.2-56.1%, p for trend < 0.001), whereas VKA use remained stable (30.8-30.5%). Of patients, 17.3% initiated OAC, 7.1% switched between OACs, 3.7% discontinued OAC treatment, while the rest underwent no change in anticoagulation status. Bleeding risk, use of concomitant antiplatelet therapy and incidence of primary dischargediagnosis of AF or ST-elevation myocardial infarction differed significantly between groups of initiation, switch, discontinuation and no change in OAC therapy. In conclusion, in patients with known AF at high risk for stroke, hospitalization was associated with an increase in OAC uptake, driven mainly by NOAC initiation. Three out of 10 patients initiated, switched or discontinued OAC treatment during hospitalization and this was associated with discrete epidemiologic parameters.

DURATION OF ANTIPLATELET THERAPY AFTER PERCUTANEOUS CORONARY INTERVENTION IN PATIENTS ON ORAL ANTICOAGULANTS IN CLINICAL PRACTICE

The optimal duration of dual antiplatelet therapy following percutaneous coronary intervention (PCI) in patients on oral anticoagulation (OAC) is controversial and requires consideration of ischemic and bleeding risk. Prescribing patterns for P2Y12 inhibitors in these patients have not been

Impact of Heart Failure Type on Thromboembolic and Bleeding Risk in Patients With Atrial Fibrillation on Oral Anticoagulation

Heart failure (HF) increases stroke risk in atrial fibrillation (AF) patients. Differential impact of HF category on thromboembolic and bleeding risk in AF patients on oral anticoagulation (OAC) is unknown. We used Medicare data for beneficiaries with new AF diagnosed between 2011 and 2013 to identify patients with HF with reduced ejection fraction (HFrEF), HF with preserved ejection fraction (HFpEF), and no HF. The primary endpoint of admission for ischemic stroke was evaluated using Cox proportional hazards regression models that controlled for patient demographics, comorbidities (including CHA2DS2-VASc and HASBLED scores), and OAC use as a time-dependent covariate. Secondary endpoints included all-cause mortality, admissions for gastrointestinal bleeding (GIB), intracranial hemorrhage (ICH), acute myocardial infarction (AMI), or HF. The 3groups included 47840, 32360, and 718392 patients respectively. Patients with HFrEF and HFpEF had higher comorbidity burden, CHA2DS2-VASc and HASBLED scores compared with patients without HF. In multivariable analysis adjusting for patient comorbidities and OAC, HFrEF and HFpEF were associated with higher risk of ischemic stroke, HF and AMI compared with no HF. HFrEF was associated with higher all-cause mortality and HF-hospitalization risk compared with HFpEF. In conclusion, in AF patients, HFrEF and HFpEF are both associated with higher risk of ischemic stroke, HF and AMI admissions, even after adjusting for OAC use, compared with patients without HF.

Perioperative Safety in Patient Under Oral Anticoagulation During Holmium Laser Enucleation of the Prostate.

To evaluate the safety of holmium laser enucleation of the prostate (HoLEP) in patients on oral anticoagulation (OA) with respect to intra- and postoperative bleeding complications. Between January 2013 and October 2016, 2178 patients were included in this study, of whom 94 received direct oral anticoagulants (DOACs) and 151 received vitamin K antagonists (VKAs) before HoLEP. All patients either ceased OA (DOACs) or were bridged subtherapeutically (VKAs, international normalized ratio <2) during surgery. These patients were compared to a sample size of 1933 nonanticoagulated patients. A significant longer postoperative stay was noted for the patients on DOACs (5.2 [4-6] days) and VKAs (5.3 [4-5] days) compared to the control group (4.5 [4-4] days). The mean drop in hemoglobin was significantly higher in the VKA group compared to the DOAC and control group. There was a significantly higher rate of postoperative bladder tamponades/secondary coagulation in patients on OA with 6 (7.9%)/3 (3.9%) patients in the DOAC group, 10 (7.4%)/6 (4.4%) patients in the VKA group compared to 37 (2.2%)/21 (2.1%) patients in the control group, respectively (p < 0.001). Eight patients required blood transfusions with a distribution of 1 (1.3%), 3 (2.2%), and 4 (0.2%) patients in the DOAC, VKA, and control group, respectively (p < 0.001). Our findings indicate that bridged patients who's DOACs and VKAs were ceased before HoLEP are at higher risk of intra- and postoperative bleeding complications. Nonetheless, HoLEP appears to be a safe and effective procedure in those patients.

Australian Experience with Left Atrial Appendage Closure in Atrial Fibrillation Post Medicare Benefits Scheme (MBS) Approval

Introduction: Percutaneous left atrial appendage closure (LAAC) was approved by the Therapeutic Goods Administration as an alternative therapy for non-valvular AF patients who are eligible for/or contraindicated to anticoagulation. MBS listing followed, expanding access for patients with restricted indications. An increase in new operators was noted. This study evaluates the procedural success and complication rates following a broader adoption of the WATCHMAN device. Methods: First 200 consecutive cases using the WATCHMAN device (Boston Scientific) post MBS listing were analysed. Data on clinical characteristics, device parameters, acute procedural outcomes and complications were available. Results: Mean age was 78 years (range 59–95), with a male predominance. AF was paroxysmal, persistent and permanent, in 52%, 16%, and 32%, respectively. Median CHA2DS2-VASc score was 4 (range 2–7). Indication for LAAC was bleeding or stroke on oral anticoagulation (OAC) in 62%, contraindication to OAC in 10%, intolerant to OAC in 4%, personal choice in 2% and unknown in 22%. Devices used per case was 1.2 (range 1–3), median device size was 27 mm, with 40% performed by inexperienced implanters. Deployment was successful in all patients. Absence of peri-implant leak was seen in 196 patients. Complications included 1 case of pericardial effusion and 1 case of the device been inadvertently disconnected from the core wire. Conclusions: Safety concerns relating to real world experience of therapeutic devices are warranted. Despite an increase in inexperienced operators, procedural success with the WATCHMAN device was high with a low incidence of complications. Continued surveillance is required to establish long-term clinical outcomes.

Evaluation of anticoagulation use and subsequent stroke in patients with atrial fibrillation after empiric surgical left atrial appendage closure: A retrospective case-control study.

Surgical exclusion of the left atrial appendage (LAA) can be performed at the time of cardiac operation as a potential modality to decrease cardioembolic risk attributable to atrial fibrillation (AF), but it remains unclear if this decreases stroke incidence. Furthermore, it is not known whether LAA exclusion impacts the decision to discontinue anticoagulation impacting subsequent stroke risk. LAA exclusion does not significantly alter subsequent anticoagulation use or stroke incidence. We studied 124 patients from Olmsted County with prior history of AF who underwent cardiac surgery at our institution between 1993 and 2015. Patients were divided into two groups on the basis of LAA exclusion and matched (1:1) according to 16 pretreatment variables using propensity scores obtained from a logistic regression model. Outcome data collected through chart review for survival, stroke, and the presence and duration of anticoagulation were compared between groups. The proportion of patients receiving anticoagulation at discharge and at 5 years was not significantly different between patients who underwent LAA exclusion and those who did not; 90% vs 81%, P = 0.156, 48% vs 49%, P = 0.722, respectively. On Kaplan-Meier analysis there were no significant differences in time free from stroke between cases and controls. Patients discharged on oral anticoagulation (OAC) had significantly lower risk of stroke (HR = 0.19, 95% confidence interval [CI] = 0.06-0.59, P = 0.004), independent of whether LAA closure was used. LAA exclusion did not appear to reduce early or late stroke. Only OAC was associated with a reduction in stroke risk, underscoring the need for continued anticoagulation in high-risk patients.

Safety and efficacy of mechanical thrombectomy with stent-retrievers in anticoagulated patients with anterior circulation stroke

To assess the safety and efficacy of mechanical thrombectomy (MT) with stent-retrievers in anterior circulation stroke (ACS) patients due to the occlusion of major cerebral arteries, and to compare the results achieved in patients on oral anticoagulation (OAC) and those not on OAC. The present retrospective study comprised 285 consecutive patients (115 males; mean age 74±13 years). The following data were collected: baseline characteristics, occurrence of risk factors, pre-event treatment with OAC, neurological deficit at the time of treatment, time to therapy, recanalisation rate (successful recanalisation defined as Thrombolysis in Cerebral Infarction score ≥2b), post-treatment imaging findings. The 90-day clinical outcome was assessed using modified Rankin scale (good outcome defined as 0-2). The following statistically insignificant differences were found in 26 patients on OAC versus 259 patients without OAC: occurrence of symptomatic intracerebral haemorrhage 7.7% versus 8.1%, achievement of successful recanalisation 69.2% versus 82.6%, good 90-day clinical outcome 34.6% versus 56.8%, 90-day mortality 26.9% versus 20.8% (p>0.05 in all cases). Age and neurological deficit at the time of treatment were identified as independent negative predictors of good 90-day clinical outcome (odds ratio [OR]=0.90, 95% confidence interval [CI]: 0.88-0.94 and OR=0.83, 95% CI: 0.77-0.90, respectively) and as independent positive predictors of mortality (OR=1.12, 95% CI: 1.06-1.18 and, OR=1.17, 95% CI: 1.07-1.27, respectively; p<0.05 in all cases). MT with stent-retrievers is safe and effective in ACS patients on OAC.

Causes and predictors of early readmission after percutaneous coronary intervention among patients discharged on oral anticoagulant therapy.

Patients discharged on oral anticoagulant (OAC) therapy after percutaneous coronary intervention (PCI) represent a complex population and are at higher risk of early readmission. The reasons and predictors of early readmission in this group have not been well characterized. We identified patients in an integrated health care system who underwent PCI between 2009 and 2014 and were readmitted within 30 days within this health care system. Of the 9,357 patients surviving to discharge after the index PCI, 692 were readmitted within 30 days (7.4%). At the time of readmission, 143 had been discharged from the index PCI hospitalization on OACs (96.5% on warfarin) and 549 had not been discharged on OACs, with readmission rates of 12.9% and 6.7%, respectively (p<0.01). The most common reason for readmission among all patients was chest pain syndromes (21.7% on OACs, 34.4% not on OACs). However, bleeding represented the next most frequent cause of readmission among patients on OACs (14.0% on OACs vs 6.0% not on OACs, p<0.01). Among patients on OAC therapy, peripheral arterial disease (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.07–2.57, p = 0.02) and nonelective PCI (OR 1.91, 95% CI 1.17–3.12, p<0.01) were found to be independent predictors of 30-day readmission. During rehospitalization, compared to patients not on OACs, patients on OACs suffered a higher unadjusted rate of mortality (6.3% vs 1.8%, p<0.01) and a longer length of stay (6.4 ± 7.1 days vs 4.9 ± 6.8 days, p = 0.02). In conclusion, patients discharged on OAC therapy after PCI are commonly readmitted, with bleeding representing a major reason. These readmissions are associated with high mortality and longer lengths of stay. Interventions targeted towards optimizing discharge planning for these complex patients are needed to potentially reduce readmissions.

Pharmacodynamic safety of clopidogrel monotherapy in patients under oral anticoagulation with a vitamin K antagonist undergoing coronary stent implantation

Current guidelines recommend as treatment option in patients on oral anticoagulation (OAC) undergoing percutaneous coronary intervention (PCI) an antiplatelet monotherapy with clopidogrel if there is an increased risk for bleeding. However, retrospective data suggested a potential interaction of clopidogrel and the vitamin K antagonist (VKA) phenprocoumon leading to a diminished antiplatelet effect. This would increase the ischemic risk of patients treated with this combination. Thus, this prospective study sought to evaluate the pharmacodynamic effect of clopidogrel monotherapy in patients on phenprocoumon undergoing PCI and assessed clinical outcomes.This study enrolled 100 patients on aspirin plus clopidogrel (DAPT-cohort, without indication for VKA) and 100 patients on clopidogrel monotherapy plus phenprocoumon (OAC-cohort) undergoing elective PCI. Platelet reactivity was assessed by impedance aggregometry on day 1 following PCI. Ischemic (death, stroke, or myocardial infarction) and bleeding (BARC 2–5) events within 12 months were compared in a propensity score adjusted model.Platelet reactivity was not different in the OAC- and DAPT-cohort (187 [127–242] vs. 167 [126–218] AU×min; p = 0.23). Overall, 17 ischemic and 34 bleeding events were recorded during follow-up. The OAC-cohort showed a nonsignificant trend to an 80% higher incidence for ischemic and bleeding events in unadjusted analyses, which disappeared following adjustment (ischemic events HR 1.07, 95%-CI 0.32–3.59, p = 0.91; bleeding events HR 1.25, 95%-CI 0.46–3.40, p = 0.67).Following PCI, the pharmacodynamic effect of a clopidogrel monotherapy together with phenprocoumon is similar as compared to DAPT without a VKA, and not associated with an increased risk for ischemic events beyond the higher underlying baseline risk.

Effect of Heart Failure Type on Thromboembolic and Bleeding Risk in Atrial Fibrillation Patients on Oral Anticoagulation

Background Heart failure (HF) increases ischemic stroke (IS) risk in atrial fibrillation (AF) patients. Differential effect of heart failure type on thromboembolic and bleeding risk while on oral anticoagulation (OAC) is unknown. Methods We used Medicare data for beneficiaries with new AF diagnosed during 2011-13 to identify patients with HF with reduced ejection fraction (HFrEF), HF with preserved ejection fraction (HFpEF), and no HF. The primary outcome of admission for IS was evaluated using Cox proportional hazards regression models that controlled for patient demographics, comorbidities (including CHA2DS2-Vasc score), and OAC use. Secondary outcomes included mortality, admissions for gastrointestinal bleeding (GIB), intracranial hemorrhage (ICH), acute myocardial infarction (AMI), or HF. Results The 3 groups included 47840, 32360 and 718392 patients respectively. Patients with HFrEF and HFpEF had higher comorbidity burden, thromboembolic and bleeding risk ( Table 1 ). In multivariable analysis adjusting for patient characteristics and OAC as a time-dependent covariate, HFrEF and HFpEF were associated with higher risk of IS, HF and AMI compared to no HF ( Table 2 ). HFrEF was associated with higher all-cause mortality and HF-hospitalization risk compared with HFpEF ( Table 2 ) Conclusion In AF patients, HFrEF and HFpEF are both associated with higher risk of stroke, HF and AMI admissions, even after adjusting for OAC, compared with patients without HF.

Antithrombotic therapy for patients with an indication for oral anticoagulation undergoing percutaneous coronary intervention with stent: The case of venous thromboembolism

The management of antithrombotic therapy in patients on oral anticoagulation (OAC) for atrial fibrillation (AF) undergoing percutaneous coronary intervention with stent (PCI) is currently addressed by expert consensus documents and official Guidelines. No specific data, nor management suggestions, are available for OAC patients undergoing PCI in whom the indication for OAC is venous thromboembolism (VTE). In this article, the available evidence on VTE patients undergoing PCI, as obtained from studies where patients with various indications for PCI were included, is evaluated, and an algorithm for the management of antithrombotic therapy in this unique population is proposed.

2135 Impact of primary care physician gatekeeping on medication prescriptions for atrial fibrillation

OBJECTIVES/SPECIFIC AIMS: Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice, and has widely varying treatments for stroke prevention and rhythm management. Some of these therapies are increasingly being prescribed by primary care physicians (PCPs). We therefore sought to investigate if healthcare plans with PCP gatekeeping for access to specialists are associated with different pharmacologic treatment strategies for the disease. In particular, we focused on oral anticoagulants (OACs), non-vitamin K-dependent oral anticoagulants (NOACs), rate control, and rhythm control medications. METHODS/STUDY POPULATION: We examined a commercial pharmaceutical claims database (Truven Marketscan™) to compare the prescription frequency of OAC, rate control, and rhythm control medications used to treat AF between patients with PCP-gated health plans (where the PCP is the gatekeeper to specialist referral—i.e., HMO, EPO, POS) and patients with non-PCP-gatekeeper health plans (i.e., comprehensive, PPO, CHDP, HDHP). To control for potential confounders, we also used multivariable logistic regression models to calculate adjusted odds ratios which accounted for age, sex, region, Charlson comorbidity index, CHADS2Vasc score, hypertension, diabetes, stroke/transient ischemic attack, prior myocardial infarction, peripheral artery disease, and antiplatelet medication use. We also calculated median time to therapy to determine if there was a difference in time to new prescription of these medications. RESULTS/ANTICIPATED RESULTS: We found only small differences between patients in PCP-gated and non-PCP-gated plans regarding prescription proportion of anticoagulants at 90 days following new AF diagnosis (OAC 44.2% vs. 42%, p&lt;0.01; warfarin 39.1% vs. 37.1%, p&lt;0.01; NOAC 5.9% vs. 6.0%, p=0.64). We observed similar trends for rate control agents (76.4% vs. 73.4%, p&lt;0.01) and rhythm control agents (24.4% vs. 24.6%, p=0.83). We found similar odds of OAC prescription at 90 days following new AF diagnosis between patients in PCP-gated and non-PCP-gated plans (adjusted OR for PCP-gated plans relative to non-gated plans: OAC 1.006, p=0.84; warfarin 1.054, p=0.08; NOAC 0.815, p=0.001; dabigatran 0.833, p=0.004; and rivaroxaban 0.181, p=0.02). We observed similar trends for rate control agents (1.166, p&lt;0.0001) and rhythm control agents (0.927, p=0.03). Elapsed time until receipt of medication was similar between PCP-gated and non-gated groups [OAC 4±14 days (interquartile range) vs. 5±16 days, p&lt;0.0001; warfarin 4±14 vs. 5±14, p&lt;0.0001; NOAC 7±26 vs. 6±23, p=0.2937; rhythm control 13±35 vs. 13±34, p=0.8661; rate control 10±25 vs. 11±30, p&lt;0.0001]. DISCUSSION/SIGNIFICANCE OF IMPACT: We found that plans with PCP gatekeeping to specialist referrals were not associated with clinically meaningful differences in prescription rates or delays in time to prescription of oral anticoagulation, rate control, and rhythm control drug therapy. In some cases, PCP gatekeeping plans had very small but statistically significant lower odds of being prescribed NOACs. These findings suggest that PCP gatekeeping does not appear to be a major structural barrier in receipt of medications for AF, although non-PCP-gated plans may vary slightly favor facilitating the prescription of NOACs. Our findings that overall OAC prescriptions did not differ by PCP gating status may suggest completion of the rapid dissemination and uptake phase for most AF treatments. The small but statistically significant odds ratios favoring the non-PCP-gated populations in NOACs further suggests that in this newer drug group, the process is ongoing, with more specialists representing early adopters. Interestingly, the low primary care odds ratio of rivaroxaban use, relative to dabigatran, may be indicative of a gradient of uptake of later-generation NOACs, although interpretability is limited by the small number of patients in the rivaroxaban group.