Cognitive Decline Over Time in Patients With Systolic Heart Failure: Insights From WARCEF.

OBJECTIVES: This study sought to characterize cognitive decline (CD) over time and its predictors in patients with systolic heart failure (HF). BACKGROUND: Despite the high prevalence of CD and its impact on mortality, predictors of CD in HF have not been established. METHODS: This study investigated CD in the WARCEF (Warfarin versus Aspirin in Reduced Ejection Fraction) trial, which performed yearly Mini-Mental State Examinations (MMSE) (higher scores indicate better cognitive function; e.g., normal score: 24 or higher). A longitudinal time-varying analysis was performed among pertinent covariates, including baseline MMSE and MMSE scores during follow-up, analyzed both as a continuous variable and a 2-point decrease. To account for a loss to follow-up, data at the baseline and at the 12-month visit were analyzed separately (sensitivity analysis). RESULTS: A total of 1,846 patients were included. In linear regression, MMSE decrease was independently associated with higher baseline MMSE score (p < 0.0001), older age (p < 0.0001), nonwhite race/ethnicity (p < 0.0001), and lower education (p < 0.0001). In logistic regression, CD was independently associated with higher baseline MMSE scores (odds ratio [OR]: 1.13; 95% confidence interval [CI]: 1.07 to 1.20]; p < 0.001), older age (OR: 1.37; 95% CI: 1.24 to 1.50; p < 0.001), nonwhite race/ethnicity (OR: 2.32; 95% CI: 1.72 to 3.13 for black; OR: 1.94; 95% CI: 1.40 to 2.69 for Hispanic vs. white; p < 0.001), lower education (p < 0.001), and New York Heart Association functional class II or higher (p = 0.03). Warfarin and other medications were not associated with CD. Similar trends were seen in the sensitivity analysis (n = 1,439). CONCLUSIONS: CD in HF is predicted by baseline cognitive status, demographic variables, and NYHA functional class. The possibility of intervening on some of its predictors suggests the need for the frequent assessment of cognitive function in patients with HF. (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction [WARCEF]; NCT00041938).

Association between mortality and implantable cardioverter-defibrillators by aetiology of heart failure: a propensity-matched analysis of the WARCEF trial.

AIMS: There is debate on whether the beneficial effect of implantable cardioverter-defibrillators (ICDs) is attenuated in patients with non-ischaemic cardiomyopathy (NICM). We assess whether any ICD benefit differs between patients with NICM and those with ischaemic cardiomyopathy (ICM), using data from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) trial. METHODS AND RESULTS: We performed a post hoc analysis using WARCEF (N = 2293; ICM, n = 991 vs. NICM, n = 1302), where participants received optimal medical treatment. We developed stratified propensity scores for having an ICD at baseline using 41 demographic and clinical variables and created 1:2 propensity-matched cohorts separately for ICM patients with ICD (N = 223 with ICD; N = 446 matched) and NICM patients (N = 195 with ICD; N = 390 matched). We constructed a Cox proportional hazards model to assess the effect of ICD status on mortality for patients with ICM and those with NICM and tested the interaction between ICD status and aetiology of heart failure. During mean follow-up of 3.5 ± 1.8 years, 527 patients died. The presence of ICD was associated with a lower risk of all-cause death among those with ICM (hazard ratio: 0.640; 95% confidence interval: 0.448 to 0.915; P = 0.015) but not among those with NICM (hazard ratio: 0.984; 95% confidence interval: 0.641 to 1.509; P = 0.941). There was weak evidence of interaction between ICD status and the aetiology of heart failure (P = 0.131). CONCLUSIONS: The presence of ICD is associated with a survival benefit in patients with ICM but not in those with NICM.

Pulse pressure and prognosis in patients with heart failure with reduced ejection fraction.

BACKGROUND: A high pulse pressure (PP) is associated with adverse cardiovascular (CV) outcomes; however, this relationship may be reversed in patients with heart failure with reduced ejection fraction (HFREF). METHODS: Patients from the WARCEF trial with left ventricular ejection fraction ≤35% were included. PP was divided into tertiles: ≤42, 42-54 and >54 mm Hg. Age and ejection fraction adjusted Kaplan-Meier curves were generated to evaluate the relationship between PP and outcomes [mortality, CV mortality, stroke and HF hospitalizations (HFH)]. Cox proportional hazards models were created incorporating PP as a continuous variable. The interaction of PP with New York Heart Association (NYHA) functional class was examined. Linear and restricted cubic splines were used to study nonlinear association between PP and outcomes. RESULTS: We included 2,299 patients with a mean(±SD) follow-up of 3.5 ± 1.8 years. The lowest tertile of PP (≤42 mm Hg) was associated with significantly higher CV mortality and HFH. Cox proportional hazards models showed a reduction in CV death and HFH with higher PP, with adjusted hazard ratios (HR) of 0.91 (P = 0.02) and 0.93 (P = 0.04) per 10 mm Hg increase in PP. This relationship was more pronounced in subjects with NYHA functional class III-IV. Spline analysis showed that the association between PP and CV mortality and HFH was only seen at PP values lower than 40 mm Hg. CONCLUSIONS: In patients with advanced HFREF, a low PP (<40 mm Hg) portends a worse prognosis, whereas a high PP (>50 mm Hg) predicts a relatively favourable prognosis.

Left atrial volume and cardiovascular outcomes in systolic heart failure: effect of antithrombotic treatment.

AIMS: Left atrium (LA) dilation is associated with adverse cardiovascular (CV) outcomes. Blood stasis, thrombus formation and atrial fibrillation may occur, especially in heart failure (HF) patients. It is not known whether preventive antithrombotic treatment may decrease the incidence of CV events in HF patients with LA enlargement. We investigated the relationship between LA enlargement and CV outcomes in HF patients and the effect of different antithrombotic treatments. METHODS AND RESULTS: Two-dimensional echocardiography with LA volume index (LAVi) measurement was performed in 1148 patients with systolic HF from the Warfarin versus Aspirin in Reduced Ejection Fraction (WARCEF) trial. Patients were randomized to warfarin or aspirin and followed for 3.4 ± 1.7 years. While the primary aim of the trial was a composite of ischaemic stroke, death, and intracerebral haemorrhage, the present report focuses on the individual CV events, whose incidence was compared across different LAVi and treatment subgroups. After adjustment for demographics and clinical covariates, moderate or severe LA enlargement was significantly associated with total death (hazard ratio 1.6 and 2.7, respectively), CV death (HR 1.7 and 3.3), and HF hospitalization (HR 2.3 and 2.6) but not myocardial infarction (HR 1.0 and 1.4) or ischaemic stroke (1.1 and 1.5). The increased risk was observed in both patients treated with warfarin or aspirin. In warfarin-treated patients, a time in therapeutic range >60% was associated with lower event rates, and an interaction between LAVi and time in therapeutic range was observed for death (P = 0.034). CONCLUSIONS: In patients with systolic HF, moderate or severe LA enlargement is associated with death and HF hospitalization despite treatment with antithrombotic medications. The possibility that achieving a more consistent therapeutic level of anticoagulation may decrease the risk of death requires further investigation.

Heart Failure Severity and Quality of Warfarin Anticoagulation Control (From the WARCEF Trial).

Previous studies in patients with atrial fibrillation showed that a history of heart failure (HF) could negatively impact anticoagulation quality, as measured by the average time in therapeutic range (TTR). Whether additional markers of HF severity are associated with TTR has not been investigated thoroughly. We aimed to examine the potential role of HF severity in the quality of warfarin control in patients with HF with reduced ejection fraction. Data from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction Trial were used to investigate the association between TTR and HF severity. Multivariable logistic regression models were used to examine the association of markers of HF severity, including New York Heart Association (NYHA) class, Minnesota Living with HF (MLWHF) score, and frequency of HF hospitalization, with TTR ≥70% (high TTR). We included 1,067 participants (high TTR, N = 413; low TTR, N = 654) in the analysis. In unadjusted analysis, patients with a high TTR were older and less likely to have had strokes or receive other antiplatelet agents. Those patients also had lower NYHA class, better MLWHF scores, greater 6-minute walk distance, and lower frequency of HF hospitalizations. Multivariable analysis showed that NYHA class III and/or IV (Odds ratio [OR] 0.68 [95% confidence intervals [CIs] 0.49 to 0.94]), each 10-point increase in MLWHF score (i.e., worse health-related quality of life) (OR 0.92 [0.86 to 0.99]), and higher number of HF hospitalization per year (OR0.45 [0.30 to 0.67]) were associated with decreased likelihood of having high TTR. In HF patients with systolic dysfunction, NYHA class III and/or IV, poor health-related quality of life, and a higher rate of HF hospitalization were independently associated with suboptimal quality of warfarin anticoagulation control. These results affirm the need to assess the new approaches, such as direct oral anticoagulants, to prevent thromboembolism in this patient population.

Aspirin Does Not Increase Heart Failure Events in Heart Failure Patients: From the WARCEF Trial.

OBJECTIVES: The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalization or death in patients with HF with reduced ejection fraction receiving an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB). BACKGROUND: Because of its cyclooxygenase inhibiting properties, aspirin has been postulated to increase HF events in patients treated with ACE inhibitors or ARBs. However, no large randomized trial has addressed the clinical relevance of this issue. METHODS: We compared aspirin and warfarin for HF events (hospitalization, death, or both) in the 2,305 patients enrolled in the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial (98.6% on ACE inhibitor or ARB treatment), using conventional Cox models for time to first event (489 events). In addition, to examine multiple HF hospitalizations, we used 2 extended Cox models, a conditional model and a total time marginal model, in time to recurrent event analyses (1,078 events). RESULTS: After adjustment for baseline covariates, aspirin- and warfarin-treated patients did not differ in time to first HF event (adjusted hazard ratio: 0.87; 95% confidence interval: 0.72 to 1.04; p = 0.117) or first hospitalization alone (adjusted hazard ratio: 0.88; 95% confidence interval: 0.73 to 1.06; p = 0.168). The extended Cox models also found no significant differences in all HF events or in HF hospitalizations alone after adjustment for covariates. CONCLUSIONS: Among patients with HF with reduced ejection fraction in the WARCEF trial, there was no significant difference in risk of HF events between the aspirin and warfarin-treated patients. (Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial [WARCEF]; NCT00041938).

Resting Heart Rate and Ischemic Stroke in Patients with Heart Failure.

BACKGROUND: Although high resting heart rate (RHR) is known to be associated with an increased risk of mortality and hospital admission in patients with heart failure, the relationship between RHR and ischemic stroke remains unclear. This study is aimed at investigating the relationship between RHR and ischemic stroke in patients with heart failure in sinus rhythm. METHODS: We examined 2,060 patients with systolic heart failure in sinus rhythm from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction trial. RHR was determined from baseline electrocardiogram, and was examined as both a continuous variable and a categorical variable using quartiles. Ischemic strokes were identified during follow-up and adjudicated by physician review. RESULTS: During 3.5 ± 1.8 years of follow-up, 77 patients (5.3% from Kaplan-Meier [KM] curve) experienced an ischemic stroke. The highest incidence of ischemic stroke (21/503 [KM 6.9%]) was observed in the lowest RHR quartile (RHR <64 beats/min) compared to other groups; 22/573 (KM 5.3%) in 64-70 beats/min, 13/465 (KM 3.5%) in 71-79 beats/min, and 21/519 (KM 5.4%) in RHR >79 beats/min (p = 0.693). Multivariable Cox proportional hazards analysis revealed that RHR was significantly associated with ischemic stroke (hazard ratio per unit decrease: 1.07, 95% CI 1.02-1.13, when RHR <64/beats/min; p = 0.038), along with a history of stroke or transient ischemic attack and left ventricular ejection fraction. CONCLUSIONS: In contrast to its beneficial effect on mortality and hospital re-admissions, lower RHR may increase the risk of ischemic stroke in patients with systolic heart failure in sinus rhythm.

CHA2 DS2 -VASc score and adverse outcomes in patients with heart failure with reduced ejection fraction and sinus rhythm.

AIMS: The aim of this study was to determine whether the CHA2 DS2 -VASc score can predict adverse outcomes such as death, ischaemic stroke, and major haemorrhage, in patients with systolic heart failure in sinus rhythm. METHODS AND RESULTS: CHA2 DS2 -VASc scores were calculated for 1101 patients randomized to warfarin and 1123 patients randomized to aspirin. Adverse outcomes were defined as death or ischaemic stroke, death alone, ischaemic stroke alone, and major haemorrhage. Using proportional hazards models, we found that each 1-point increase in the CHA2 DS2 -VASc score was associated with increased hazard of death or ischaemic stroke events [hazard ratio (HR) for the warfarin arm = 1.21, 95% confidence interval (CI) 1.13-1.30, P < 0.001; for aspirin, HR = 1.20, 95% CI 1.11-1.29, P < 0.001]. Similar increased hazards for higher CHA2 DS2 -VASc scores were observed for death alone, ischaemic stroke alone, and major haemorrhage. Overall performance of the CHA2 DS2 -VASc score was assessed using c-statistics for full models containing the risk score, treatment assignment, and score-treatment interaction, with the c-statistics for the full models ranging from 0.57 for death to 0.68 for major haemorrhage. CONCLUSIONS: The CHA2 DS2 -VASc score predicted adverse outcomes in patients with systolic heart failure in sinus rhythm, with modest prediction accuracy.

Left Ventricular Ejection Fraction and Risk of Stroke and Cardiac Events in Heart Failure: Data From the Warfarin Versus Aspirin in Reduced Ejection Fraction Trial.

BACKGROUND AND PURPOSE: In heart failure (HF), left ventricular ejection fraction (LVEF) is inversely associated with mortality and cardiovascular outcomes. Its relationship with stroke is controversial, as is the effect of antithrombotic treatment. We studied the relationship of LVEF with stroke and cardiovascular events in patients with HF and the effect of different antithrombotic treatments. METHODS: In the Warfarin Versus Aspirin in Reduced Ejection Fraction (WARCEF) trial, 2305 patients with systolic HF (LVEF≤35%) and sinus rhythm were randomized to warfarin or aspirin and followed for 3.5±1.8 years. Although no differences between treatments were observed on primary outcome (death, stroke, or intracerebral hemorrhage), warfarin decreased the stroke risk. The present report compares the incidence of stroke and cardiovascular events across different LVEF and treatment subgroups. RESULTS: Baseline LVEF was inversely and linearly associated with primary outcome, mortality and its components (sudden and cardiovascular death), and HF hospitalization, but not myocardial infarction. A relationship with stroke was only observed for LVEF of <15% (incidence rates: 2.04 versus 0.95/100 patient-years; P=0.009), which more than doubled the adjusted stroke risk (adjusted hazard ratio, 2.125; 95% CI, 1.182-3.818; P=0.012). In warfarin-treated patients, each 5% LVEF decrement significantly increased the stroke risk (adjusted hazard ratio, 1.346; 95% CI, 1.044-1.737; P=0.022; P value for interaction=0.04). CONCLUSIONS: In patients with systolic HF and sinus rhythm, LVEF is inversely associated with death and its components, whereas an association with stroke exists for very low LVEF values. An interaction with warfarin treatment on stroke risk may exist. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00041938.

Clinical and Echocardiographic Factors Associated With New-Onset Atrial Fibrillation in Heart Failure　- Subanalysis of the WARCEF Trial.

BACKGROUND: Heart failure (HF) patients have a high incidence of new-onset AF. Given the adverse prognostic influence of AF in HF, identifying patients at high risk of developing AF is important. METHODS AND RESULTS: The incidence and factors associated with new-onset AF were investigated in patients in sinus rhythm with reduced LVEF enrolled in the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) trial. Analyses involved clinical factors alone (n=2,219), and clinical plus echocardiographic findings (n=1,125). During 3.5±1.8 years of follow-up, 212 patients (9.6% of total cohort) developed AF. In both samples, new-onset AF was associated with age, male sex, White race, and IHD. Among echocardiographic variables, only LAD predicted AF. On multivariate Cox modeling, age (HR, 1.02; 95% CI: 1.00-1.03, P=0.008), IHD (HR, 1.37; 95% CI: 1.02-1.84, P=0.036) and LAD (HR, 1.48; 95% CI: 1.15-1.91, P=0.003) remained associated with AF onset. Patients with IHD, LAD>4.5 cm and age>50 years had a 2.5-fold higher risk of AF than patients without any of these characteristics (HR, 2.52; 95% CI: 1.72-3.69, P<0.0001). CONCLUSIONS: Age, IHD and LAD independently predict new-onset AF in HF patients in sinus rhythm, at younger age and smaller LAD than generally believed. This information may be useful to risk-stratify HF patients for AF development, allowing close monitoring and possibly early detection. (Circ J 2016; 80: 619-626).

The first prognostic model for stroke and death in patients with systolic heart failure.

BACKGROUND: Patients with systolic heart failure (HF) are at increased risk of both ischemic stroke and death. Currently, no risk scores are available to identify HF patients at high risk of stroke or death. The Warfarin vs. Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) trial studied 2305 HF patients, in sinus rhythm, followed for up to 6 years (3.5±1.5 years). This trial showed no overall difference in those treated with warfarin vs aspirin with regard to death or stroke. The present study develops the first prognostic model to identify patients at higher risk of stroke or death based on their overall risk profile. METHODS AND RESULTS: A scoring algorithm using 8 readily obtainable clinical characteristics as predictors, age, gender, hemoglobin, blood urea nitrogen, ejection fraction, diastolic blood pressure, diabetes status, and prior stroke or transient ischemic attack (C-index=0.65, 95% CI: 0.613-0.681), was developed. It was validated internally using a bootstrap method. In predicting 1-year survival for death alone, our 8-predictor model had an AUC of 0.63 (95% CI: 0.579-0.678) while the 14-predictor Seattle model had an AUC of 0.72. The Seattle model did not report stroke. CONCLUSIONS: This novel prognostic model predicts the overall risk of ischemic stroke or death for HF patients. This model compares favorably for death with the Seattle model and has the added utility of including stroke as an endpoint. Use of this model will help identify those patients in need of more intensive monitoring and therapy and may help identify appropriate populations for trials of new therapies. CLINICAL TRIAL REGISTRATION: http://www.Clinicatrials.govNCT00041938.

Bleeding Risk and Antithrombotic Strategy in Patients With Sinus Rhythm and Heart Failure With Reduced Ejection Fraction Treated With Warfarin or Aspirin.

We sought to assess the performance of existing bleeding risk scores, such as the Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly (HAS-BLED) score or the Outpatient Bleeding Risk Index (OBRI), in patients with heart failure with reduced ejection fraction (HFrEF) in sinus rhythm (SR) treated with warfarin or aspirin. We calculated HAS-BLED and OBRI risk scores for 2,305 patients with HFrEF in SR enrolled in the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction trial. Proportional hazards models were used to test whether each score predicted major bleeding, and comparison of different risk scores was performed using Harell C-statistic and net reclassification improvement index. For the warfarin arm, both scores predicted bleeding risk, with OBRI having significantly greater C-statistic (0.72 vs 0.61; p = 0.03) compared to HAS-BLED, although the net reclassification improvement for comparing OBRI to HAS-BLED was not significant (0.32, 95% confidence interval [CI] -0.18 to 0.37). Performance of the OBRI and HAS-BLED risk scores was similar for the aspirin arm. For participants with OBRI scores of 0 to 1, warfarin compared with aspirin reduced ischemic stroke (hazard ratio [HR] 0.51, 95% CI 0.26 to 0.98, p = 0.042) without significantly increasing major bleeding (HR 1.24, 95% CI 0.66 to 2.30, p = 0.51). For those with OBRI score of ≥2, there was a trend for reduced ischemic stroke with warfarin compared to aspirin (HR 0.56, 95% CI 0.27 to 1.15, p = 0.12), but major bleeding was increased (HR 4.04, 95% CI 1.99 to 8.22, p <0.001). In conclusion, existing bleeding risk scores can identify bleeding risk in patients with HFrEF in SR and could be tested for potentially identifying patients with a favorable risk/benefit profile for antithrombotic therapy with warfarin.

Quality of anticoagulation control in preventing adverse events in patients with heart failure in sinus rhythm: Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction trial substudy.

BACKGROUND: The aim of this study is to examine the relationship between time in the therapeutic range (TTR) and clinical outcomes in heart failure patients in sinus rhythm treated with warfarin. METHODS AND RESULTS: We used data from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) trial to assess the relationship of TTR with the WARCEF primary outcome (ischemic stroke, intracerebral hemorrhage, or death), with death alone, ischemic stroke alone, major hemorrhage alone, and net clinical benefit (primary outcome and major hemorrhage combined). Multivariable Cox models were used to examine how the event risk changed with TTR and to compare the high TTR, low TTR, and aspirin-treated patients, with TTR being treated as a time-dependent covariate. A total of 2217 patients were included in the analyses; among whom 1067 were randomized to warfarin and 1150 were randomized to aspirin. The median (interquartile range) follow-up duration was 3.6 (2.0-5.0) years. Mean (±SD) age was 61±11.3 years, with 80% being men. The mean (±SD) TTR was 57% (±28.5%). Increasing TTR was significantly associated with reduction in primary outcome (adjusted P<0.001), death alone (adjusted P=0.001), and improved net clinical benefit (adjusted P<0.001). A similar trend was observed for the other 2 outcomes, but significance was not reached (adjusted P=0.082 for ischemic stroke and adjusted P=0.109 for major hemorrhage). CONCLUSIONS: In patients with heart failure in sinus rhythm, increasing TTR is associated with better outcome and improved net clinical benefit. Patients in whom good quality anticoagulation can be achieved may benefit from the use of anticoagulants. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00041938.

Cognitive function in ambulatory patients with systolic heart failure: insights from the warfarin versus aspirin in reduced cardiac ejection fraction (WARCEF) trial.

We sought to determine whether cognitive function in stable outpatients with heart failure (HF) is affected by HF severity. A retrospective, cross-sectional analysis was performed using data from 2, 043 outpatients with systolic HF and without prior stroke enrolled in the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) Trial. Multivariable regression analysis was used to assess the relationship between cognitive function measured using the Mini-Mental Status Exam (MMSE) and markers of HF severity (left ventricular ejection fraction [LVEF], New York Heart Association [NYHA] functional class, and 6-minute walk distance). The mean (SD) for the MMSE was 28.6 (2.0), with 64 (3.1%) of the 2,043 patients meeting the cut-off of MMSE <24 that indicates need for further evaluation of cognitive impairment. After adjustment for demographic and clinical covariates, 6-minute walk distance (ß-coefficient 0.002, p<0.0001), but not LVEF or NYHA functional class, was independently associated with the MMSE as a continuous measure. Age, education, smoking status, body mass index, and hemoglobin level were also independently associated with the MMSE. In conclusion, six-minute walk distance, but not LVEF or NYHA functional class, was an important predictor of cognitive function in ambulatory patients with systolic heart failure.

Stroke in heart failure in sinus rhythm: the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction trial.

BACKGROUND: The Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction trial found no difference between warfarin and aspirin in patients with low ejection fraction in sinus rhythm for the primary outcome: first to occur of 84 incident ischemic strokes (IIS), 7 intracerebral hemorrhages or 531 deaths. Prespecified secondary analysis showed a 48% hazard ratio reduction (p = 0.005) for warfarin in IIS. Cardioembolism is likely the main pathogenesis of stroke in heart failure. We examined the IIS benefit for warfarin in more detail in post hoc secondary analyses. METHODS: We subtyped IIS into definite, possible and noncardioembolic using the Stroke Prevention in Atrial Fibrillation method. Statistical tests, stratified by prior ischemic stroke or transient ischemic attack, were the conditional binomial for independent Poisson variables for rates, the Cochran-Mantel-Haenszel test for stroke subtype and the van Elteren test for modified Rankin Score (mRS) and National Institute of Health Stroke Scale (NIHSS) distributions, and an exact test for proportions. RESULTS: Twenty-nine of 1,142 warfarin and 55 of 1,163 aspirin patients had IIS. The warfarin IIS rate (0.727/100 patient-years, PY) was lower than for aspirin (1.36/100 PY, p = 0.003). Definite cardioembolic IIS was less frequent on warfarin than aspirin (0.22 vs. 0.55/100 PY, p = 0.012). Possible cardioembolic IIS tended to be less frequent on warfarin than aspirin (0.37 vs. 0.67/100 PY, p = 0.063) but noncardioembolic IIS showed no difference: 5 (0.12/100 PY) versus 6 (0.15/100 PY, p = 0.768). Among patients experiencing IIS, there were no differences by treatment arm in fatal IIS, baseline mRS, mRS 90 days after IIS, and change from baseline to post-IIS mRS. The warfarin arm showed a trend to a lower proportion of severe nonfatal IIS [mRS 3-5; 3/23 (13.0%) vs. 16/48 (33.3%), p = 0.086]. There was no difference in NIHSS at the time of stroke (p = 0.825) or in post-IIS mRS (p = 0.948) between cardioembolic, possible cardioembolic and noncardioembolic stroke including both warfarin and aspirin groups. CONCLUSIONS: The observed benefits in the reduction of IIS for warfarin compared to aspirin are most significant for cardioembolic IIS among patients with low ejection fraction in sinus rhythm. This is supported by trends to lower frequencies of severe IIS and possible cardioembolic IIS in patients on warfarin compared to aspirin.

Benefit of warfarin compared with aspirin in patients with heart failure in sinus rhythm: a subgroup analysis of WARCEF, a randomized controlled trial.

BACKGROUND: The Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) trial found no difference in the primary outcome between warfarin and aspirin in 2305 patients with reduced left ventricular ejection fraction in sinus rhythm. However, it is unknown whether any subgroups benefit from warfarin or aspirin. METHODS AND RESULTS: We used a Cox model stepwise selection procedure to identify subgroups that may benefit from warfarin or aspirin on the WARCEF primary outcome. A secondary analysis added major hemorrhage to the outcome. The primary efficacy outcome was time to the first to occur of ischemic stroke, intracerebral hemorrhage, or death. Only age group was a significant treatment effect modifier (P for interaction, 0.003). Younger patients benefited from warfarin over aspirin on the primary outcome (4.81 versus 6.76 events per 100 patient-years: hazard ratio, 0.63; 95% confidence interval, 0.48-0.84; P=0.001). In older patients, therapies did not differ (9.91 versus 9.01 events per 100 patient-years: hazard ratio, 1.09; 95% confidence interval, 0.88-1.35; P=0.44). With major hemorrhage added, in younger patients the event rate remained lower for warfarin than aspirin (5.41 versus 7.25 per 100 patient-years: hazard ratio, 0.68; 95% confidence interval, 0.52-0.89; P=0.005), but in older patients it became significantly higher for warfarin (11.80 versus 9.35 per 100 patient-years: hazard ratio, 1.25; 95% confidence interval, 1.02-1.53; P=0.03). CONCLUSIONS: In patients <60 years, warfarin improved outcomes over aspirin with or without inclusion of major hemorrhage. In patients ≥60 years, there was no treatment difference, but the aspirin group had significantly better outcomes when major hemorrhage was included.

Warfarin and aspirin in patients with heart failure and sinus rhythm.

BACKGROUND: It is unknown whether warfarin or aspirin therapy is superior for patients with heart failure who are in sinus rhythm. METHODS: We designed this trial to determine whether warfarin (with a target international normalized ratio of 2.0 to 3.5) or aspirin (at a dose of 325 mg per day) is a better treatment for patients in sinus rhythm who have a reduced left ventricular ejection fraction (LVEF). We followed 2305 patients for up to 6 years (mean [±SD], 3.5±1.8). The primary outcome was the time to the first event in a composite end point of ischemic stroke, intracerebral hemorrhage, or death from any cause. RESULTS: The rates of the primary outcome were 7.47 events per 100 patient-years in the warfarin group and 7.93 in the aspirin group (hazard ratio with warfarin, 0.93; 95% confidence interval [CI], 0.79 to 1.10; P=0.40). Thus, there was no significant overall difference between the two treatments. In a time-varying analysis, the hazard ratio changed over time, slightly favoring warfarin over aspirin by the fourth year of follow-up, but this finding was only marginally significant (P=0.046). Warfarin, as compared with aspirin, was associated with a significant reduction in the rate of ischemic stroke throughout the follow-up period (0.72 events per 100 patient-years vs. 1.36 per 100 patient-years; hazard ratio, 0.52; 95% CI, 0.33 to 0.82; P=0.005). The rate of major hemorrhage was 1.78 events per 100 patient-years in the warfarin group as compared with 0.87 in the aspirin group (P<0.001). The rates of intracerebral and intracranial hemorrhage did not differ significantly between the two treatment groups (0.27 events per 100 patient-years with warfarin and 0.22 with aspirin, P=0.82). CONCLUSIONS: Among patients with reduced LVEF who were in sinus rhythm, there was no significant overall difference in the primary outcome between treatment with warfarin and treatment with aspirin. A reduced risk of ischemic stroke with warfarin was offset by an increased risk of major hemorrhage. The choice between warfarin and aspirin should be individualized. (Funded by the National Institute of Neurological Disorders and Stroke; WARCEF ClinicalTrials.gov number, NCT00041938.).