Temporal trends in lifetime risks of atrial fibrillation and its complications between 2000 and 2022: Danish, nationwide, population based cohort study

OBJECTIVES

To examine how the lifetime risks of atrial fibrillation and of complications after atrial fibrillation changed over time.

DESIGN

Danish, nationwide, population based cohort study.

SETTING

Population of Denmark from 1 January 2000 to 31 December 2022.

PARTICIPANTS

3.5 million individuals (51.7% women and 48.3% men) who did not have atrial fibrillation at 45 years of age or older were followed up until incident atrial fibrillation, migration, death, or end of follow-up, whichever came first. All 362 721 individuals with incident atrial fibrillation (46.4% women and 53.6% men), but with no prevalent complication, were further followed up until incident heart failure, stroke, or myocardial infarction.

MAIN OUTCOME MEASURES

Lifetime risk of atrial fibrillation and lifetime risks of complications after atrial fibrillation over two prespecified periods (2000-10 v 2011-22).

RESULTS

The lifetime risk of atrial fibrillation increased from 24.2% in 2000-10 to 30.9% in 2011-22 (difference 6.7% (95% confidence interval 6.5% to 6.8%)). After atrial fibrillation, the most frequent complication was heart failure with a lifetime risk of 42.9% in 2000-10 and 42.1% in 2011-22 (-0.8% (-3.8% to 2.2%)). Individuals with atrial fibrillation lost 14.4 years with no heart failure. The lifetime risks of stroke and of myocardial infarction after atrial fibrillation decreased slightly between the two periods, from 22.4% to 19.9% for stroke (-2.5% (-4.2% to -0.7%)) and from 13.7% to 9.8% for myocardial infarction (-3.9% (-5.3% to -2.4%). No evidence was reported of a differential decrease between men and women.

CONCLUSION

Lifetime risk of atrial fibrillation increased over two decades of follow-up. In individuals with atrial fibrillation, about two in five developed heart failure and one in five had a stroke over their remaining lifetime after atrial fibrillation diagnosis, with no or only small improvement over time. Stroke risks and heart failure prevention strategies are needed for people with atrial fibrillation.

Efficacy and safety of oral anticoagulants according to kidney function among patients with atrial fibrillation

BACKGROUND AND AIMS

Patients with severely reduced kidney function have been excluded from randomized controlled trials and data on safety and efficacy of direct oral anticoagulants (DOACs) according to kidney function remain sparse. The aim was to evaluate safety and efficacy of the DOACs across subgroups of kidney function.

METHODS

Using multiple Danish nationwide registers and laboratory databases, we included patients initiated on oral anticoagulants (OACs) with atrial fibrillation and available creatinine level and followed patients for 2 years to evaluate occurrence of stroke/thromboembolism (TE) and major bleeding.

RESULTS

Among 26,686 included patients, 3667 (13.7%) had an estimated glomerular filtration rate (eGFR) of 30-49 mL/min/1.73m2 and 596 (2.2%) had an eGFR below 30 mL/min/1.73m2. We found no evidence of differences regarding the risk of stroke/TE between the OACs (p-value interaction>0.05 for all). Apixaban was associated with a lower 2-year risk of major bleeding compared to VKA (risk ratio 0.79, 95% confidence interval (CI) 0.67-0.93), and the risk difference was significantly larger among patients with reduced kidney function (p-value interaction 0.018). Rivaroxaban was associated with higher risk of bleeding compared to apixaban (risk ratio 1.78, 95%CI 1.32-2.39) among patients with eGFR 30-49 mL/min/1.73m2.

CONCLUSIONS

Overall, we found no differences regarding the risk of stroke/TE, but apixaban was associated with a 21% lower relative risk of major bleeding compared to VKA. This risk reduction was even greater when comparing apixaban and rivaroxaban among patients with eGFR 15-30 mL/min/1.73m2, and when comparing apixaban to dabigatran and rivaroxaban among patients with eGFR 30-49 mL/min/1.73m2.

Novel Risk Modeling Approach of Atrial Fibrillation With Restricted Mean Survival Times: Application in the Framingham Heart Study Community-Based Cohort

BACKGROUND

Risk prediction models for atrial fibrillation (AF) do not give information about when AF might develop. Restricted mean survival time (RMST) quantifies risk into the time domain. Our objective was to use RMST to re-express individualized AF risk predictions.

METHODS AND RESULTS

We included AF-free participants from the Framingham Heart Study community-based cohorts. We predicted new-onset AF over 10-year follow-up according to baseline covariates: age, height, weight, systolic blood pressure, diastolic blood pressure, current smoking, antihypertensive treatment, diabetes mellitus, prevalent heart failure, and prevalent myocardial infarction. First, we fitted a Cox regression model and estimated the 10-year predicted risk of AF. Second, we fitted an RMST model and estimated the predicted mean time free of AF and alive over a time horizon of 10 years. We included 7586 AF-free participants contributing to 11 088 examinations (mean age 61±11 years, 44% were men). During 10-year follow-up, 822 participants developed AF. The Cox and RMST models were in agreement regarding the direction, strength, and statistical significance of associations for all covariates. Low (<5%), intermediate (5%-15%), and high (>15%) 10-year predicted risk of AF corresponded to predicted mean time alive and free of AF of 9.9, 9.6, and 8.8 years, respectively. A 60-year-old woman with a body mass index of 25 kg/m2, no use of hypertension treatment and no history of heart failure had a predicted mean time alive and free of AF of 9.9 years, whereas a 70-year-old man with a body mass index of 30 kg/m2, use of hypertension treatment, and with prevalent heart failure had a predicted mean time alive and free of AF of 7.9 years.

CONCLUSIONS

The RMST can be used to develop risk prediction models to express results in a time scale. RMST may offer a complementary risk communication tool for AF in clinical practice.

Rivaroxaban Versus Apixaban for Stroke Prevention in Atrial Fibrillation

Background:

The comparative effectiveness of non-vitamin K antagonist oral anticoagulants (NOACs) is uncertain, as they have not been compared directly in randomized trials. Previous observational comparisons of NOACs are likely to be biased by unmeasured confounders. We sought to compare the efficacy and safety of rivaroxaban and apixaban for stroke prevention in patients with atrial fibrillation (AF), using practice variation in preference for NOAC as an instrumental variable.

Methods and Results:

Patients started on apixaban or rivaroxaban after newly diagnosed AF were identified using Danish nationwide registries. Patients were categorized according to facility preferences for type of NOAC, independent of actual treatment, measured as fraction of the prior 20 patients with AF initiated on rivaroxaban in the same facility. Facility preference for NOAC was used as an instrumental variable. The occurrence of stroke/thromboembolism, major bleeding, myocardial infarction, and all-cause mortality over 2 years of follow-up were investigated using adjusted Cox regressions. We analyzed 6264 patients with AF initiated on rivaroxaban or apixaban. NOAC preference was strongly related to actual choice of treatment but not associated with any other measured baseline characteristics. Patients treated in facilities that had preference for rivaroxaban had more major bleeding: compared with patients treated in facilities that used rivaroxaban in 0% to 20% of cases, the adjusted hazard ratio for bleeding was 1.06 when treated in a facility with 25% to 40% use; 1.41 with 45% to 60% use; 1.51 with 65% to 80% use; and 1.81 with 0% to 100% use ( P trend =0.01). Higher facility preference for rivaroxaban was not significantly associated with increased risk of stroke/thromboembolism ( P trend =0.06), myocardial infarction ( P trend =0.65), or all-cause mortality ( P trend =0.89). When we used the instrumental variable to model the causal relationship between choice of NOAC and major bleeding, relative risk with rivaroxaban was 1.89 (95% CI, 1.06–2.72) compared with apixaban.

Conclusions:

Using instrumental variable estimation in a cohort of patients with AF, rivaroxaban was associated with higher risk of major bleeding compared with apixaban. No significant associations to other outcomes were found in main analyses.

All-cause mortality, stroke, and bleeding in patients with atrial fibrillation and valvular heart disease

AIMS 

To compare the risk of all-cause mortality, stroke, and bleeding in patients with atrial fibrillation (AF) and valvular heart disease (VHD) treated with vitamin K antagonist (VKA) or factor Xa-inhibitors (FXa-I; rivaroxaban and apixaban).

METHODS AND RESULTS 

We cross-linked data from Danish nationwide registries identifying patients with AF and VHD (aortic stenosis/insufficiency, mitral insufficiency, bioprosthetic heart valves, mitral-, and aortic valve repair) initiating VKA or FXa-I between January 2014 and June 2017. Outcomes were all-cause mortality, stroke, and bleeding. Using cause-specific Cox regression, we reported the standardized absolute 2-year risk of the outcomes and absolute risk differences (ARD). We identified 1115 (41.7%), 620 (23.1%), and 942 (35.2%) patients initiating treatment with VKA, rivaroxaban, and apixaban, respectively. The standardized absolute risk (95% confidence interval) of all-cause mortality associated with VKA treatment was 34.1% (30.4-37.8%) with corresponding ARD for FXa-I of -2.7% (-6.7% to 1.4%). The standardized absolute risk of stroke for VKA was 3.8% (2.2-5.4%) with corresponding ARD for FXa-I of -0.1% (-2.0% to 1.8%). The standardized risk of bleeding for VKA was 10.4% (7.2-12.9%) with corresponding ARD for FXa-I of -2.0% (-5.1% to 1.1%). The risk of bleeding was significantly reduced in subgroup analyses of apixaban compared with VKA [ARD: -3.9% (-7.0% to -0.9%)] and rivaroxaban [ARD: -5.6% (-9.5% to -1.7%)].

CONCLUSION 

In this nationwide cohort study, there were no significant differences in the risks of all-cause mortality, stroke, and bleeding in patients with AF and VHD treated with VKA compared with FXa-I.

Protein Biomarkers and Risk of Atrial Fibrillation: The FHS

BACKGROUND

Identification of protein biomarkers associated with incident atrial fibrillation (AF) may improve the understanding of the pathophysiology, risk prediction, and development of new therapeutics for AF. We examined the associations between 85 protein biomarkers and incident AF.

METHODS

We included participants ≥50 years of age from the FHS (Framingham Heart Study) Offspring and Third Generation cohorts, who had 85 fasting plasma proteins measured using Luminex xMAP platform. Hazard ratios (per 1 SD increment of rank-normalized biomarker [hazard ratio]) and 95% CIs for incident AF were calculated using Cox regression models adjusted for age, sex, height, weight, current smoking, systolic blood pressure, diastolic blood pressure, hypertension treatment, diabetes mellitus, valvular heart disease, prevalent myocardial infarction, and prevalent heart failure. We used the false discovery rate to account for multiple testing.

RESULTS

The study sample comprised 3378 participants (54% women) with mean (SD) age of 61.5 (8.4) years. In total, 401 developed AF over a mean follow-up of 12.3±3.8 years. We observed lower hazard of incident AF associated with higher mean levels of IGF1 (insulin-like growth factor 1; hazard ratio per 1 SD increment in protein level, 0.84 [95% CI, 0.76-0.93]), and higher hazard of incident AF associated with higher mean levels of both IGFBP1 (insulin-like growth factor-binding protein 1; hazard ratio, 1.24 [95% CI, 1.1-1.39]) and NT-proBNP (N-terminal pro-B-type natriuretic peptide; hazard ratio, 1.73 [95% CI, 1.52-1.96]).

CONCLUSIONS

Decreased levels of IGF1 and increased levels of IGFBP1 and NT-proBNP were associated with higher risk of incident AF.

Resumption of oral anticoagulation following traumatic injury and risk of stroke and bleeding in patients with atrial fibrillation: a nationwide cohort study

Aims

We examined the risks of all-cause mortality, stroke, major bleeding, and recurrent traumatic injury associated with resumption of vitamin K antagonists (VKAs) and non-VKAs oral anticoagulants (NOACs) following traumatic injury in atrial fibrillation (AF) patients.

Methods and results

This was a Danish nationwide registry-based study (2005-16), including 4541 oral anticoagulant (OAC)-treated AF patients experiencing traumatic injury (defined as traumatic brain injury, hip fracture, or traumatic torso or abdominal injury). Within 90 days following discharge from traumatic injury, 60.6% resumed VKA (median age = 80, CHA2DS2-VASc = 4, HAS-BLED = 2), 16.7% resumed NOAC (median age = 81, CHA2DS2-VASc = 4, HAS-BLED = 2), and 22.7% did not resume OAC treatment (median age = 81, CHA2DS2-VASc = 4, HAS-BLED = 3). Switch from VKA to NOAC occurred among 9.5%. Since 2009, the trend in OAC resumption increased (P-value <0.0001), in particular with NOACs (P-value <0.0001). Follow-up started 90 days after discharge, and time-varying multiple Cox regression analyses were used for comparisons. Compared with non-resumption, VKA and NOAC resumption were associated with lower hazard [95% confidence interval (CI)] of all-cause mortality [hazard ratio (HR) 0.48 (0.42-0.53) and HR 0.55 (0.47-0.66), respectively] and ischaemic stroke [HR 0.56 (0.43-0.72) and HR 0.54 (0.35-0.82), respectively], increased major bleeding hazard [HR 1.30 (1.03-1.64) and HR 1.15 (0.81-1.63), respectively], and similar hazard of recurrent traumatic injury [HR 0.93 (0.73-1.18) and HR 0.87 (0.60-1.27), respectively].

Conclusion

AF patients resuming VKA and NOAC treatment following traumatic injury have lower hazard of all-cause mortality and ischaemic stroke, increased hazard of major bleeding but without additional hazards of recurrent traumatic injury. Withholding OAC following a traumatic injury in AF patients may not be warranted.

Risk of gastrointestinal bleeding associated with oral anticoagulation and non-steroidal anti-inflammatory drugs in patients with atrial fibrillation: a nationwide study

Aims

Non-vitamin K antagonist oral anticoagulants (NOACs) are displacing vitamin K antagonists (VKAs) for stroke prophylaxis in patients with atrial fibrillation (AF). Concomitant use of non-steroidal anti-inflammatory drugs (NSAIDs) could increase gastrointestinal bleeding (GIB) risks among these patients. The aim of this study was to examine the risk of GIB among Danish AF patients taking oral anticoagulants (OACs) and NSAIDs.

Methods and results

Using nationwide administrative registries, we determined concomitant NSAID use among anticoagulant-naïve patients with AF initiating OACs between August 2011 and June 2017. We calculated short-term absolute risks differences and hazard ratios (HRs) for GIB based on multiple adjusted cause-specific Cox regressions with time-dependent NSAID treatment. Among 41 183 patients [median age 70 years (interquartile range 64–78); 55% men], 21% of patients on NOACs and 18% on VKA were co-prescribed NSAIDs. The differences in absolute risk [95% confidence interval (CI)] of GIB within 14 days of commencing concomitant NSAID therapy (vs. no concomitant NSAID therapy) were 0.10% (0.04–0.18%) for NOACs and 0.13% (0.03–0.24%) for VKA. NOACs overall were associated with less GIB than VKA [HR 0.77 (95% CI 0.69–0.85)]. Compared with OACs alone, concomitant NSAIDs doubled the GIB risk associated with NOACs overall [HR 2.01 (95% CI 1.40–2.61)] and with VKA [HR 1.95 (95% CI 1.21–2.69)].

Conclusion

Among this nationwide AF population taking OACs, concomitant NSAID therapy increased the short-term absolute risk of GIB. Non-vitamin K antagonist oral anticoagulants alone were associated with lower GIB risks than VKA but concomitant NSAIDs abolished this advantage. The findings align with post hoc analyses from randomized studies. Physicians should exercise appropriate caution when prescribing NSAIDs for patients with AF taking NOACs or VKA.

Switching from vitamin K antagonist to dabigatran in atrial fibrillation: differences according to dose

AIMS

In atrial fibrillation (AF) patients 150 mg b.i.d. dabigatran is the standard dose, yet guidelines recommend 110 mg b.i.d. when bleeding risk is high. It is unknown to which extend these recommendations are followed in patients switching from vitamin K antagonist (VKA) to dabigatran. The aim of this study was to investigate if AF patients are switched from VKA to the appropriate dose of dabigatran.

METHODS AND RESULTS

Using nationwide registries (22 August 2011 to 31 December 2012), we identified VKA-experienced AF patients with available creatinine values who switched to dabigatran. European guidelines criteria 2012 on dabigatran dosing were examined: age ≥80 years, HAS-BLED ≥3, estimated glomerular filtration rate (eGFR)<50 mL/min/1.73 m2, or use of interacting drugs. We identified 1626 VKA-experienced AF patients who switched to dabigatran 110 mg (820 patients) or 150 mg (806 patients). Patients who switched to 110 mg compared with 150 mg were older [median age 82 years (Q1-Q3: 77-86) vs. 68 years (Q1-Q3: 64-74)], more often females (54% vs. 35%), had a higher comorbidity burden, higher proportion with CHA2DS2-VASc score ≥2 (98% vs. 80%), and more with a HAS-BLED score ≥3 (46% vs. 28%). Patients switched to 110 mg had a higher absolute risk of mortality compared with patients switched to 150 mg. Overall, 26% were inappropriately dosed and 14% were switched to 110 mg although the higher dose was indicated. Furthermore, 39% of patients switched to 150 mg fulfilled one or more criteria for 110 mg, this mostly driven by high HAS-BLED scores (28.2% of patients on 150 mg). Female sex, age ≥80 years, eGFR < 50 mL/min/1.73 m2, drugs interacting with dabigatran, and prior bleeding were associated with switch to 110 mg. Patients inappropriately dosed had similar risk of mortality as patients appropriately dosed.

CONCLUSION

Among VKA-experienced AF patients one in four were switched to a dabigatran dose contrary to guideline recommendations.

Non-vitamin K antagonist oral anticoagulants vs. vitamin-K antagonists in patients with atrial fibrillation and chronic kidney disease: a nationwide cohort study

Background

We aimed to compare effectiveness and safety of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin-K antagonists (VKA) in atrial fibrillation (AF) patients with chronic kidney disease (CKD) not receiving dialysis.

Methods

By using personal identification numbers, we cross-linked individual-level data from Danish administrative registries. We identified every citizen with a prior diagnosis of AF and CKD who initiated NOAC or VKA (2011–2017). An external analysis of 727 AF patients with CKD (no dialysis) was performed to demonstrate level of kidney function in a comparable population. Study outcomes included incidents of stroke/thromboembolisms (TEs), major bleedings, myocardial infarctions (MIs), and all-cause mortality. We used Cox proportional hazards models to determine associations between oral anticoagulant treatment and outcomes.

Results

Of 1560 patients included, 1008 (64.6%) initiated VKA and 552 (35.4%) initiated NOAC. In a comparable population we found that 95.3% of the patients had an estimated glomerular filtration rate (eGFR) < 59 mL/min. Patients treated with NOAC had a significantly decreased risk of major bleeding (hazard ratio (HR): 0.47, 95% confidence interval (CI): 0.26–0.84) compared to VKA. There was not found a significant association between type of anticoagulant and risk of stroke/TE (HR: 0.83, 95% CI: 0.39–1.78), MI (HR: 0.45, 95% CI: 0.18–1.11), or all-cause mortality (HR: 0.99, 95% CI: 0.77–1.26).

Conclusion

NOAC was associated with a lower risk of major bleeding in patients with AF and CKD compared to VKA. No difference was found in risk of stroke/TE, MI, and all-cause mortality.

P4792Dabigatran versus vitamin K antagonists in patients with atrial fibrillation and valvular heart disease

Background

Atrial fibrillation (AF) and valvular heart disease (VHD) are both associated with an increased risk of stroke. Outside post-hoc analyses of randomized controlled trials, knowledge on the effectiveness and safety of dabigatran in patients with AF and VHD is scarce.

Objectives

To compare the risk of all-cause mortality, stroke, and bleeding in patients with AF and VHD treated with dabigatran or a vitamin K antagonist (VKA).

Methods

All Danish residents are provided a unique personal identification number enabling cross-linking of data from Danish nationwide registries. We identified all patients with AF and VHD initiating treatment with dabigatran or VKA between the 22nd of August 2011 and the 31st of December 2014. We defined VHD as aortic stenosis/regurgitation, mitral regurgitation, bioprosthetic heart valves, mitral-, and aortic valve repair. Outcomes were all-cause mortality, stroke, and bleeding. 2-year standardized absolute risks were calculated from cause-specific Cox regression models with death as competing risk.

Results

In total, 599 (27.3%) and 1,596 (72.7%) patients initiated treatment with dabigatran and VKA. The 2-year standardized absolute risk of all-cause mortality (95% CI) for VKA was 27.6% (25.1% to 30.1%) and 25.4% (21.8% to 29.0%) for dabigatran with a corresponding absolute risk difference of −2.2% (−6.3% to 1.9%) (Figure 1). The 2-year standardized absolute risk of stroke for VKA was 3.4% (2.3% to 4.5%) and 3.9% (2.2% to 5.5%) for dabigatran with a corresponding absolute risk difference of 0.5% (−1.6% to 2.5%). Lastly, the 2-year standardized absolute risk of bleeding for VKA was 8.2% (6.6% to 9.7%) and 7.6% (5.1% to 10.1%) for dabigatran with a corresponding absolute risk difference of −0.5% (−3.4% to 2.4%).

Figure 1

Conclusions

In this nationwide cohort study, we found no significant difference in the risk of all-cause mortality, stroke, or bleeding in patients with AF and VHD when comparing VKA to dabigatran.

P4779High facility preference for rivaroxaban in atrial fibrillation increases risk of major bleeding compared to facility preference for apixaban

Background

No randomized trial has compared efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) in atrial fibrillation (AF). Previous real-world comparisons could be biased by patient characteristics of importance for treatment selection, but instrumental variables could potentially account for measured and unmeasured confounders.

Purpose

To compare efficacy and safety of rivaroxaban and apixaban using facility preference for type of NOAC as instrumental variable.

Methods

AF patients started on apixaban or rivaroxaban were identified using nationwide registries. We categorized patients according to facility preference for type of NOAC, measured as percentage of the prior 20 AF patients started on rivaroxaban in the same facility. Occurrence of stroke/thromboembolism (TE), major bleeding, myocardial infarction and all-cause mortality during two years of follow-up were investigated using adjusted Cox regressions. To further examine general frailty according to facility preferences we also investigated occurrence of cancer, urogenital tract infection, dehydration and fracture.

Results

We analyzed 6264 AF patients initiated on rivaroxaban or apixaban. Compared with patients treated in facilities that used rivaroxaban in 0–20% of cases, the adjusted hazard ratio for bleeding was 1.05 when treated in a facility with 25–40% use; 1.40 with 45–60% use; 1.50 with 65–80% use; and 1.81 for 85–100% use (Ptrend=0.002). Higher facility level use of rivaroxaban was not associated with increased risk of stroke/TE (Ptrend=0.06), myocardial infarction (Ptrend=0.87) or all-cause mortality (Ptrend=0.91), and there was no association between facility preference for rivaroxaban and risk of cancer (Ptrend=0.83), urogenital tract infection (Ptrend=0.49), dehydration (Ptrend=0.91) or fracture (Ptrend=0.47).

Characteristics by facility preference Percent of previous AF patients from facility started on rivaroxaban P for trend 0–20% 25–40% 45–60% 65–80% 85–100% No. of patients 1406 1421 1551 930 956 Received rivaroxaban, (%) 279, (19.8) 499, (35.1) 711, (45.8) 632, (68.0) 774, (81.0) <0.001 Standard dose, (%) 1216, (86.5) 1232, (86.7%) 1366, (88.1%) 793, (85.3%) 824, (86.2%) 0.62 Median age, (interquartile range) 70, (63.3–74) 69, (63–74) 70, (64–74) 70, (64–75) 70, (63–75) 0.11 Below median income, (%) 740, (52.6) 699, (49.2) 764, (49.3) 458, (49.3) 471, (49.3) 0.31 Prior stroke, (%) 99, (7.0) 115, (8.1) 134, (8.6) 69, (7.4) 74, (7.7) 0.56 Prior bleeding, (%) 136, (9.7) 141, (9.9) 163, (10.5) 91, (9.8) 97, (10.1) 0.51 Antiplatelet therapy, (%) 445, (31.7) 465, (32.7) 491, (31.7) 303, (32.6) 317, (33.2) 0.49

Rate of events according to instrument

Conclusion

High facility preference for rivaroxaban increases risk of major bleeding compared to facility preference for apixaban.

Acknowledgement/Funding

This study was funded by an unrestricted grant from the Capital Region of Denmark, Foundation for Health Research.

P4757Vitamin k antagonists are associated with higher risk of osteoporotic fractures compared to non-vitamin k antagonist oral anticoagulants among atrial fibrillation patients: a nationwide cohort study

Background/Introduction

Osteoporotic fractures are associated with high mortality and reduced life quality in an elderly population. Several studies report an increased risk of fractures among patients treated with oral anticoagulants (OAC), however, only sparse research has been made to clarify the difference between treatment with vitamin K antagonists (VKA) and non-VKA oral anticoagulants (NOACs) regarding the risk of osteoporotic fractures.

Purpose

The purpose of this study was to evaluate the risk of osteoporotic fractures among patients with atrial fibrillation (AF) in long-term VKA or NOAC treatment.

Methods

Patients with AF were identified using Danish national registries and were included when they had undergone 180 days OAC treatment, and only if they had no prior use of osteoporosis medication. The study period was from 1 January 2013 until 30 June 2017, and patients were followed for 2 years, or until death, outcome or emigration. Outcomes were hip fracture, major osteoporotic fracture, any fracture, initiation of osteoporosis medication, and a combined endpoint. G-formula was used to determine standardized absolute risk, and multiple covariate adjusted Cox regressions were used to calculate hazard ratios (HR).

Results

Overall, 37,350 patients with AF were included; 32.6% received VKA treatment (median age 72 years, 61.8% men) and 67.4% received NOAC treatment (median age 73 years, 55.9% men). The standardized absolute 2-year risk of any fracture was low among NOAC treated patients (3.1%; 95% CI: 2.9% to 3.3%), and among VKA treated patients (3.8%; 95% CI: 3.4% to 4.2%).

NOAC was associated with a significantly lower relative risk of any fracture (HR: 0.85; 95% CI: 0.74 to 0.97), of major osteoporotic fractures (HR: 0.85; 95% CI: 0.72 to 0.99), and of initiating osteoporotic medication (HR: 0.82; 95% CI: 0.71 to 0.95). A combined endpoint showed that patients treated with NOAC had a significantly lower risk of suffering from any fracture or initiating osteoporosis medication (HR: 0.84; 95% CI: 0.76 to 0.93).

Adjusted relative two-year risks

Conclusion

In a nationwide population, the absolute risk of osteoporotic fractures was low among AF patients on OAC, but NOAC was associated with a significantly lower risk of osteoporotic fractures compared to VKA.

Acknowledgement/Funding

Scholarship from The Copenhagen University Hospital Herlev and Gentofte

3154The incidence of atrial fibrillation continues to increase across all socioeconomic subgroups: 30-year time trends from a Nationwide cohort

Introduction

The incidence rate of atrial fibrillation (AF) has increased substantially throughout the last decades. Socioeconomic factors such as income and education are well known to be associated with the development of cardiovascular disease, however, the impact on long-term trends of AF incidence rates is yet to be described.

Purpose

This nationwide cohort study examined the temporal trends of AF incidence rates over a span of 30 years (from 1987 to 2016) in Denmark. Furthermore, the impact of income and education was outlined.

Method

Patients were identified through linkage across Danish national registries from 1987 to 2016. We extracted data on the total number of inhabitants in Denmark aged ≥18 years, and used their age, sex, civil status, income and educational level for each calendar year. Data on socio economics were available from 1994. Income was defined by the average income over the prior 5 years and grouped into low (&lt;q1),&gt;Q3). Educational level was divided into primary school, high school, bachelor's degree, or master's degree. We defined incident AF as all first-time in- and outpatient diagnoses of AF. The incidence rates of AF were age-standardized per 1000 person-years for each calendar year and calculated for men and women separately.

Results

A total of 6,968,997 Danish inhabitants aged ≥18 years contributed to the study population from 1987 to 2016, and 393,183 (6%) developed AF over the study period. The age-standardized incidence rates of AF per 1000 person-years increased from 1.23 (CI 1.15:1.30) to 4.05 (CI 3.93:4.17) for men and from 1.13 (CI 1.06:1.30) to 3.56 (CI 3.44:3.68) for women from 1987 to 2016. Income status and educational level influenced the age-standardized incidence rates more significantly in women than men. The incidence rate from 1994 to 2016 for women with low income increased by a factor of 2.1 from 2.0 (CI 1.89:2.21) to 4.36 (CI 4.03:4.73). However, the high income group increased by a factor of 1.6 (from 1.74 (CI 1.10:3.32) to 2.83 (CI 2.29:3.55) per 1000 person-years). Moreover, the incidence rate for women with low educational level increased from 1.60 (CI 0.95:5.97) to 4.01 (CI 3.80:4.23) per 1000 person-years. The high educational group increased only by 1.2 (from 2.55 (CI 0.77:10.38) to 3.1 (CI 3.32:4.11) per 1000 person-years).

Conclusion

In a nationwide population, the incidence rate of AF continued to increase during a 30-year period. All socioeconomic subgroups experienced an increase in AF incidence, but the impact of low socioeconomic status was more significant among women than among men. The progressive growth in AF incidence has significant public health implications.

Acknowledgement/Funding

Danish Heart Foundation

Outcomes Among Patients With Atrial Fibrillation and Appropriate Anticoagulation Control

BACKGROUND

Atrial fibrillation (AF) patients on a vitamin K antagonist (VKA) with time in therapeutic range (TTR) ≥70% are not recommended to switch to a direct oral anticoagulant according to guidelines.

OBJECTIVES

This study sought to assess future TTR and risk of stroke/thromboembolism and major bleeding among AF patients on VKA with TTR ≥70%.

METHODS

The authors used Danish nationwide registries to identify AF patients on VKA from 1997 to 2011 with available international normalized ratio values. Patients were included 6 months after VKA initiation, divided according to TTR, and followed for 12 months after inclusion. Cox proportional hazard models estimated hazard ratios (HRs). TTR was examined both as a baseline variable and as a time-dependent covariate in the Cox models.

RESULTS

Of the 4,772 included AF patients still on VKA 6 months after initiation, 1,691 (35.4%) had a TTR ≥70%, and 3,081 (65.6%) had a TTR <70%. Among patients with prior TTR ≥70% still on treatment 12 months after inclusion, only 513 (55.7%) still had a TTR ≥70%. Compared with prior TTR ≥70%, prior TTR <70% was not associated with a higher risk of stroke/thromboembolism (HR: 1.14; 95% confidence interval [CI]: 0.77 to 1.70) or major bleeding (HR: 1.12; 95% CI: 0.84 to 1.49). When the authors estimated TTR time-dependently during follow-up, TTR <70% was associated with an increased risk of stroke/thromboembolism (HR: 1.91; 95% CI: 1.30 to 2.82) and major bleeding (HR: 1.34; 95% CI: 1.02 to 1.76).

CONCLUSIONS

Among AF patients on VKA, almost one-half of patients with prior TTR ≥70% had TTR <70% during the following year. Prior TTR ≥70% per se had limited long-term prognostic value.

Thiazolidinediones are associated with a decreased risk of atrial fibrillation compared with other antidiabetic treatment: a nationwide cohort study

Aim

The aim of this study was to investigate the association between thiazolidinediones (TZDs) vs. other antidiabetic drugs and risk of atrial fibrillation (AF) in diabetic patients.

Method and results

Diabetes mellitus (diabetes) increases the risk of AF by approximately 34%. TZD is an insulin sensitizer that also has anti-inflammatory effects, which might decrease the risk of AF compared with other antidiabetic drugs. We used data from the Danish nationwide registries to study 108 624 patients with diabetes and without prior AF who were treated with metformin or sulfonylurea as first-line drugs. The incidence of AF was significantly lower with TZD as the second-line antidiabetic treatment compared with other second-line antidiabetic drugs (P < 0.001). The 10 year cumulative incidence [95% confidence interval (95% CI)] of AF was 6.2% (3.1-9.3%) with TZD vs. 10.2% (9.8-10.6%) with other antidiabetic drugs. The decreased risk of AF remained significant after adjusting for age, sex, and comorbidities with a hazard ratio (95% CI) of 0.76 (0.57-1.00), P = 0.047 associated with TZD treatment compared with other antidiabetic drugs.

Conclusion

Use of a TZD to treat diabetes was associated with reduced risk of developing AF compared with other antidiabetic drugs as second-line treatment.

Ischaemic and haemorrhagic stroke associated with non-vitamin K antagonist oral anticoagulants and warfarin use in patients with atrial fibrillation: a nationwide cohort study

Background

Non-vitamin K antagonist (VKA) oral anticoagulants (NOACs) are widely used as stroke prophylaxis in non-valvular atrial fibrillation (AF), but comparative data are sparse.

Purpose

To compare dabigatran, rivaroxaban, and apixaban vs. VKA and the risk of stroke/thromboembolism (TE) and intracranial bleeding in AF.

Methods

Using Danish nationwide registries (2011-15), anticoagulant-naïve AF patients were identified when initiating VKA or an NOAC. Outcomes were stroke/TE and intracranial bleeding. Multiple outcome-specific Cox regression was performed to calculate average treatment effects as standardized differences in 1-year absolute risks.

Results

Overall, 43 299 AF patients initiated VKA (42%), dabigatran (29%), rivaroxaban (13%), and apixaban (16%). Mean CHA2DS2-VASc (SD) score was: VKA 2.9 (1.6), dabigatran 2.7 (1.6), rivaroxaban 3.0 (1.6), and apixaban 3.1 (1.6). Within patient-specific follow-up limited to the first 2 years, 1054 stroke/TE occurred and 261 intracranial bleedings. Standardized absolute risk (95% CI) of stroke/TE at 1 year after initiation of VKA was 2.01% (1.80% to 2.21%). In relation to VKA, the absolute risk differences were for dabigatran 0.11% (-0.16% to 0.42%), rivaroxaban 0.05% (-0.33% to 0.48%), and apixaban 0.45% (-0.001% to 0.93%). For the intracranial bleeding outcome, the standardized absolute risk at 1 year was for VKA 0.60% (0.49% to 0.72%); the corresponding absolute risk differences were for dabigatran -0.34% (-0.47% to - 0.21%), rivaroxaban -0.13% (-0.33% to 0.08%), and apixaban -0.20% (-0.38% to - 0.01%).

Conclusions

Among anticoagulant-naïve AF patients, treatment with NOACs was not associated with significantly lower risk of stroke/TE compared with VKA, but intracranial bleeding risk was significantly lower with dabigatran and apixaban.

Increased use of oral anticoagulants in patients with atrial fibrillation: temporal trends from 2005 to 2015 in Denmark

Aim

The aim of this study is to examine temporal trends in the use oral anticoagulants (OAC) as stroke prophylaxis in patients with atrial fibrillation (AF) and to examine factors associated with OAC initiation.

Methods and results

From Danish nationwide registries, we identified patients diagnosed with AF at Danish hospitals and outpatient clinics between January 2005 and June 2015. OAC initiation was assessed from prescription fills ±180 days from date of AF diagnosis. We identified a total of 108 410 patients with newly diagnosed AF. Before 2010, 40-50% initiated OAC treatment. From 2010, OAC initiation rates increased (P < 0.0001 for trend) and by June 2015, 66.5% of the incident AF patients were initiated on OAC (74.5% increase since December 2009). Increased OAC prescription was especially seen among females and 'fragile' patients (age > 75 years and high risk of stroke). The increased OAC initiation was accompanied by introduction and increased uptake of the NOACs. By the end of the study, NOACs accounted for 72.5% of all OACs prescribed in newly diagnosed AF patients. OAC initiation was associated with male gender, age 65-74 years, few comorbidities and increased risk of stroke.

Conclusion

Since 2010, more incident AF patients in Denmark were initiated on OAC therapy with predominant NOAC prescription. The increase was pronounced among females, among patients at high risk of stroke, and among older patients.

Lifetime risk of atrial fibrillation according to optimal, borderline, or elevated levels of risk factors: cohort study based on longitudinal data from the Framingham Heart Study

OBJECTIVE

To examine the association between risk factor burdens-categorized as optimal, borderline, or elevated-and the lifetime risk of atrial fibrillation.

DESIGN

Community based cohort study.

SETTING

Longitudinal data from the Framingham Heart Study.

PARTICIPANTS

Individuals free of atrial fibrillation at index ages 55, 65, and 75 years were assessed. Smoking, alcohol consumption, body mass index, blood pressure, diabetes, and history of heart failure or myocardial infarction were assessed as being optimal (that is, all risk factors were optimal), borderline (presence of borderline risk factors and absence of any elevated risk factor), or elevated (presence of at least one elevated risk factor) at index age.

MAIN OUTCOME MEASURE

Lifetime risk of atrial fibrillation at index age up to 95 years, accounting for the competing risk of death.

RESULTS

At index age 55 years, the study sample comprised 5338 participants (2531 (47.4%) men). In this group, 247 (4.6%) had an optimal risk profile, 1415 (26.5%) had a borderline risk profile, and 3676 (68.9%) an elevated risk profile. The prevalence of elevated risk factors increased gradually when the index ages rose. For index age of 55 years, the lifetime risk of atrial fibrillation was 37.0% (95% confidence interval 34.3% to 39.6%). The lifetime risk of atrial fibrillation was 23.4% (12.8% to 34.5%) with an optimal risk profile, 33.4% (27.9% to 38.9%) with a borderline risk profile, and 38.4% (35.5% to 41.4%) with an elevated risk profile. Overall, participants with at least one elevated risk factor were associated with at least 37.8% lifetime risk of atrial fibrillation. The gradient in lifetime risk across risk factor burden was similar at index ages 65 and 75 years.

CONCLUSIONS

Regardless of index ages at 55, 65, or 75 years, an optimal risk factor profile was associated with a lifetime risk of atrial fibrillation of about one in five; this risk rose to more than one in three a third in individuals with at least one elevated risk factor.

Restarting oral anticoagulant therapy after major bleeding in atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Use of oral anticoagulant (OAC) therapy in atrial fibrillation (AF) is associated with an inherited risk of bleeding. Benefits and risks of OAC restarting after a major bleeding are still uncertain. We aimed to assess effectiveness and safety of restarting OAC in AF patients after a major bleeding event.

METHODS

We performed a systematic review and meta-analysis of all studies reporting data about AF patients that sustained a major bleeding, reporting data on restarting or not restarting OAC therapy.

RESULTS

A total of seven studies were included, involving 5685 patients. No significant difference was found in "any stroke" occurrence between OAC restarters and non-restarters (odds ratio [OR]: 0.75, 95% confidence interval [CI]: 0.37-1.51), with a significant 46% relative risk reduction (RRR) (p < 0.00001) for "any thromboembolism" in OAC restarters, with consistent results when the index bleeding event was an intracranial or gastrointestinal bleeding. A significantly higher risk of recurrent major bleeding was seen (OR: 1.85, 95% CI: 1.48-2.30), but no difference in risk for recurrence of index event. OAC restarters had a 10.8% absolute risk reduction for all-cause death (OR: 0.38, 95% CI: 0.24-0.60); p < 0.00001). Net clinical benefit (NCB) analysis demonstrated that restarting OAC therapy after a major bleeding was significantly associated with a clinical advantage (NCB: 0.11, 95% CI: 0.09-0.14; p < 0.001).

CONCLUSIONS

Restarting OAC therapy after a major bleeding event in AF was associated with a positive clinical benefit when compared to non-restarting OAC, with a significant reduction in any thromboembolism and all-cause mortality.

Standard and reduced doses of dabigatran, rivaroxaban and apixaban for stroke prevention in atrial fibrillation: a nationwide cohort study

BACKGROUND

Comparative data of non-vitamin K antagonist oral anticoagulants (NOAC) are lacking in patients with atrial fibrillation (AF).

OBJECTIVE

We compared effectiveness and safety of standard and reduced dose NOAC in AF patients.

METHODS

Using Danish nationwide registries, we included all oral anticoagulant-naïve AF patients who initiated NOAC treatment (2012-2016). Outcome-specific and mortality-specific multiple Cox regressions were combined to compute average treatment effects as 1-year standardized differences in stroke and bleeding risks (g-formula).

RESULTS

Amongst 31 522 AF patients, the distribution of NOAC/dose was as follows: dabigatran standard dose (22.4%), dabigatran-reduced dose (14.0%), rivaroxaban standard dose (21.8%), rivaroxaban reduced dose (6.7%), apixaban standard dose (22.9%), and apixaban reduced dose (12.2%). The 1-year standardized absolute risks of stroke/thromboembolism were 1.73-1.98% and 2.51-2.78% with standard and reduced NOAC dose, respectively, without statistically significant differences between NOACs for given dose level. Comparing standard doses, the 1-year standardized absolute risk (95% CI) for major bleeding was for rivaroxaban 2.78% (2.42-3.17%); corresponding absolute risk differences (95% CI) were for dabigatran -0.93% (-1.45% to -0.38%) and apixaban, -0.54% (-0.99% to -0.05%). The results for major bleeding were similar for reduced NOAC dose. The 1-year standardized absolute risk (95% CI) for intracranial bleeding was for standard dose dabigatran 0.19% (0.22-0.50%); corresponding absolute risk differences (95% CI) were for rivaroxaban 0.23% (0.06-0.41%) and apixaban, 0.18% (0.01-0.34%).

CONCLUSIONS

Standard and reduced dose NOACs, respectively, showed no significant risk difference for associated stroke/thromboembolism. Rivaroxaban was associated with higher bleeding risk compared with dabigatran and apixaban and dabigatran was associated with lower intracranial bleeding risk compared with rivaroxaban and apixaban.

Renal Function, Time in Therapeutic Range and Outcomes in Warfarin-Treated Atrial Fibrillation Patients: A Retrospective Analysis of Nationwide Registries

Patients with severely reduced renal function have been excluded from randomized controlled trials of oral anticoagulation in atrial fibrillation (AF). Warfarin treatment in this population is controversial and data on anticoagulation control and the impact on adverse outcomes are needed. By individual-level linkage of nationwide registries, we identified all patients discharged from hospitals with AF in Denmark between 1997 and 2011. Patients with available serum creatinine tests were categorized according to the estimated glomerular filtration rate (eGFR). Time in therapeutic range (TTR) was calculated using the Rosendaal method. The risk of stroke and bleeding was estimated using multivariable Cox regression analyses with eGFR and TTR estimated time dependently throughout follow-up. We identified 10,423 warfarin-treated AF patients with available international normalized ratio and creatinine tests; 5,527 with eGFR > 60 mL/min/1.73 m2, 4,524 with eGFR 30–60 mL/min/1.73 m2 and 372 with eGFR < 30 mL/min/1.73 m2. Median TTR was 66.7, 61.2 and 49.7% in patients with eGFR > 60, 30–59 and <30 mL/min/1.73 m2, respectively. A TTR < 70% was associated with a higher risk of stroke/thromboembolism (hazard ratio [HR]: 1.39; 95% confidence interval [CI]: 1.20–1.60) and bleeding (HR: 1.22; 95% CI: 1.05–1.42) among patients with eGFR of 30 to 59 and a trend towards higher risk of stroke/thromboembolism (HR: 1.24; 95% CI: 0.86–1.80) and bleeding (HR: 1.17; 95% CI: 0.83–1.65) among patients with eGFR < 30 mL/min/1.73 m2. In conclusion, warfarin-treated AF patients with reduced renal function have suboptimal anticoagulation control which was related to the risk of adverse outcomes.

Comparative safety and effectiveness of rivaroxaban versus VKAs in patients with venous thromboembolism

The approval of rivaroxaban has changed the landscape of treatment of venous thromboembolism (VTE). Little is known about the effect of rivaroxaban compared with vitamin K antagonists (VKA), when used in the everyday clinical practice. The aim of this study was to investigate the safety and effectiveness of rivaroxaban compared with VKAs among patients with VTE, using the Danish nationwide registries. All patients diagnosed with VTE and treated with either rivaroxaban or VKAs between 2013 and 2015 were included. A total of 12,318 patients were diagnosed with VTE and treated with VKAs [n=6,907] or rivaroxaban [n=5,411.]. Combined Cox regression analyses showed that the standardised absolute six-month risk of recurrent VTE was 3.03 % [95 % CI: 2.57 % to 3.48 %] in the rivaroxaban group and 3.13 % [95 % CI: 2.70 % to 3.56 %] in the VKA group (absolute risk difference of –0.11 % [95 % CI: –0.76 % to 0.54 %]). The standardised absolute six-months risk of bleeding was 2.28 % [95 % CI: 1.87 % to 2.67 %] for patients in the rivaroxaban group and 2.10 % [95 % CI: 1.78 % to 2.43 %] in the VKA group (absolute risk difference of 0.18 % [95 % CI: –0.34 % to 0.67]). In conclusion, rivaroxaban was associated with similar risk of recurrent VTE and bleeding compared with VKA.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Association Between Leukocyte Telomere Length and the Risk of Incident Atrial Fibrillation: The Framingham Heart Study

Background

Advancing age is a prominent risk factor for atrial fibrillation (AF). Shorter telomere length is a biomarker of biological aging, but the link between shorter telomere length and increased risk of AF remains unclear. We examined the association between shorter leukocyte telomere length (LTL) and incident AF.

Methods and Results

We included AF‐free participants from the observational Framingham Heart Study Offspring cohort from 1995 to 1998, who had LTL measurements. We examined the association between baseline LTL and incident AF with multivariable Cox models adjusted for age, sex, current smoking, height, weight, systolic and diastolic blood pressure, use of antihypertensive medication, diabetes mellitus, history of myocardial infarction, and history of heart failure. The study sample comprised 1143 AF‐free participants (52.8% women), with mean age of 60±8 years. The mean LTL at baseline was 6.95±0.57 kb. During 15.1±4.2 years mean follow‐up, 184 participants (64 women) developed AF. Chronological age was associated with increased risk of AF (hazard ratio per 10‐year increase, 2.16; 95% confidence interval, 1.71–2.72). There was no significant association between LTL and incident AF (hazard ratio per 1 SD decrease LTL, 1.01; 95% confidence interval, 0.86–1.19). Our study was observational in nature; hence, we could not exclude residual confounding and we were unable to establish causal pathways.

Conclusions

In our moderate‐sized community‐based cohort, we did not find evidence for a significant association between LTL and risk of incident AF.

Genetic Predisposition, Clinical Risk Factor Burden, and Lifetime Risk of Atrial Fibrillation

BACKGROUND

The long-term probability of developing atrial fibrillation (AF) considering genetic predisposition and clinical risk factor burden is unknown.

METHODS

We estimated the lifetime risk of AF in individuals from the community-based Framingham Heart Study. Polygenic risk for AF was derived using a score of ≈1000 AF-associated single-nucleotide polymorphisms. Clinical risk factor burden was calculated for each individual using a validated risk score for incident AF comprised of height, weight, systolic and diastolic blood pressure, current smoking status, antihypertensive medication use, diabetes mellitus, history of myocardial infarction, and history of heart failure. We estimated the lifetime risk of AF within tertiles of polygenic and clinical risk.

RESULTS

Among 4606 participants without AF at 55 years of age, 580 developed incident AF (median follow-up, 9.4 years; 25th-75th percentile, 4.4-14.3 years). The lifetime risk of AF >55 years of age was 37.1% and was substantially influenced by both polygenic and clinical risk factor burden. Among individuals free of AF at 55 years of age, those in low-polygenic and clinical risk tertiles had a lifetime risk of AF of 22.3% (95% confidence interval, 15.4-9.1), whereas those in high-risk tertiles had a risk of 48.2% (95% confidence interval, 41.3-55.1). A lower clinical risk factor burden was associated with later AF onset after adjusting for genetic predisposition (P<0.001).

CONCLUSIONS

In our community-based cohort, the lifetime risk of AF was 37%. Estimation of polygenic AF risk is feasible and together with clinical risk factor burden explains a substantial gradient in long-term AF risk.

Use of oral anticoagulants in combination with antiplatelet(s) in atrial fibrillation

Objectives

To investigate temporal trends in the use of non-vitamin K oral anticoagulants (NOACs) and vitamin K antagonists (VKAs) in combination with aspirin and/or clopidogrel in patients with atrial fibrillation (AF) following acute myocardial infarction (MI) and/or percutaneous coronary intervention (PCI).

Methods

Using Danish nationwide registries, all patients with AF who survived 30 days after discharge from MI and/or PCI between 22 August 2011 and 30 September 2016 were identified.

Results

A total of 2946 patients were included in the study population, of whom 1967 (66.8%) patients were treated with VKA in combination with antiplatelet(s) (VKA+aspirin n=477, VKA+clopidogrel n=439, VKA+aspirin+clopidogrel n=1051) and 979 (33.2%) patients were treated with NOAC in combination with antiplatelet(s) (NOAC+aspirin n=252, NOAC+clopidogrel n=218, NOAC+aspirin+clopidogrel n=509). The overall study population had a median age of 76 years [IQR: 69–82] and consisted of 1995 (67.7%) men. Patients with MI as inclusion event accounted for 1613 patients (54.8%). Patients with high CHA2DS2-VASc score(congestive heart failure, hypertension, age ≥75 years (2 points), diabetes mellitus, history of stroke/transient ischemic attack/systemic thromboembolism (2 points), vascular disease, age 65-75 years, and female sex) accounted for 132 2814 (95.5%) of patients, and patients with high HAS-BLED score (hypertension, abnormal renal/liver function, history of stroke, history of bleeding, age >65 years, non-steroidal anti-inflammatory drug usages, or alcohol abuse, leaving out labile international normalized ratio (not available), and use of antiplatelets (exposure variable)) accounted for 934 (31.7%) of patients. There was an increase from 10% in 2011 to 52% in 2016 in the use of NOACs in combination with antiplatelet(s).

Conclusion

From 2011 to 2016, the use of NOAC in combination with antiplatelet(s) increased in patients with AF following MI/PCI and exceeded the use of VKA in combination with antiplatelet(s) by 2016.

Predicted risk of stroke and bleeding and use of oral anticoagulants in atrial fibrillation: Danish nationwide temporal trends 2011-2016

INTRODUCTION, MATERIALS AND METHODS

We used Danish nationwide registries to examine temporal trends in the predicted stroke and bleeding risks (mean CHA₂DS₂-VASc and HAS-BLED scores per year, respectively) as well as the combination of selected stroke and bleeding risk factors per year among atrial fibrillation (AF) patients initiated for the first time between 2011 and 2016 on vitamin K antagonists (VKAs), dabigatran, rivaroxaban, or apixaban.

RESULTS

In total, 53,860 AF patients were included (VKA 37.7%, dabigatran 24.4%, rivaroxaban 16.9%, apixaban 21.0%). For standard dose dabigatran initiators, during almost all of the study period, the mean CHA₂DS₂-VASc and HAS-BLED scores were the lowest and decreased (2.6 and 2.2 in 2011 vs. 2.1 and 1.8 in 2016, respectively). Reduced dose apixaban initiators had rather stable mean CHA₂DS₂-VASc scores during the study period and the highest mean CHA₂DS₂-VASc score in 2016 (4.1). The mean HAS-BLED scores were similarly high among reduced dose apixaban and rivaroxaban initiators in years 2013-2016. From 2011 to 2014, a decrease in the frequency of prior stroke (p<0.001), age≥75years (p<0.001), and prior bleeding (p=0.007) was observed among dabigatran initiators. In the study period, apixaban initiators in general had the highest frequency of prior stroke and age≥75years.

CONCLUSIONS

Danish AF patients receiving standard dose dabigatran had the lowest and decreasing predicted stroke and bleeding risks during almost all study years. Patients receiving reduced dose apixaban had rather stable predicted risk of stroke during the study period and the highest mean CHA₂DS₂-VASc score in 2016.

Initiation of anticoagulation in atrial fibrillation: which factors are associated with choice of anticoagulant?

BACKGROUND

The use of non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prophylaxis in atrial fibrillation (AF) is increasing rapidly. We compared characteristics of AF patients initiated on NOACs versus vitamin K antagonists (VKAs).

METHODS

Using Danish nationwide registry data, we identified AF patients initiating either a VKA or a NOAC from 22 August 2011 until 30 September 2016. We compared patient characteristics including age, gender, comorbidities, concomitant pharmacotherapy and CHA₂ DS₂ -VASc and HAS-BLED scores in patients initiated on a VKA, dabigatran, rivaroxaban or apixaban. Differences were examined using multivariable logistic regression models.

RESULTS

The study population comprised 51 981 AF patients of whom 19 989 (38.5%) were initiated on a VKA, 13 242 (25.5%) on dabigatran, 8475 (16.3%) on rivaroxaban and 10 275 (19.8%) on apixaban. Those patients initiated on apixaban had higher mean ± SD CHA₂ DS₂ -VASc scores than those initiated on a VKA (3.1 ± 1.6 vs. 2.9 ± 1.6). Those initiated on dabigatran had lower mean CHA₂ DS₂ -VASc scores (2.7 ± 1.6) than all other groups. Patients with a history of a prior stroke were significantly more likely to be initiated on a NOAC compared with a VKA [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.28-1.43]. By contrast, patients with a history of myocardial infarction were less likely to be initiated on a NOAC compared with a VKA (OR 0.72, 95% CI 0.67-0.77).

CONCLUSIONS

Atrial fibrillation patients who were initiated on apixaban had higher stroke risk scores than patients initiated on VKAs. Interestingly, opposite results were found for dabigatran.

Relations of Liver Fat With Prevalent and Incident Atrial Fibrillation in the Framingham Heart Study

Background

Obesity is an important risk factor for nonalcoholic fatty liver disease and atrial fibrillation (AF). Less is known about the relations between nonalcoholic fatty liver disease and AF. We sought to evaluate the association between fatty liver and prevalent and incident AF in the community.

Methods and Results

We examined Framingham Heart Study participants who underwent a study‐directed computed tomography scan, had hepatic steatosis (HS) evaluated, and did not report heavy alcohol use between 2002 and 2005. We evaluated cross‐sectional associations between liver fat and prevalent AF with logistic regression models. We assessed the relations between liver fat and incident AF during 12‐year follow‐up with Cox proportional hazards models. Of 2122 participants (53% women; mean age, 59.0±9.6 years), 20% had HS. AF prevalence (n=62) among individuals with HS was 4% compared to 3% among those without HS. There was no significant association between HS (measured as continuous or dichotomous variables) and prevalent AF in age‐ and sex‐adjusted or multivariable‐adjusted models. Incidence of AF (n=153) among participants with and without HS was 8.7 cases and 7.8 cases per 1000 person‐years, respectively. In age‐ and sex‐adjusted and multivariable‐adjusted models, there were no significant associations between continuous or dichotomous measures of HS and incident AF.

Conclusions

In our community‐based, longitudinal cohort study, liver fat by computed tomography scan was not significantly associated with increased prevalence or incidence of AF over 12 years of follow‐up.

Atrial Fibrillation: Epidemiology, Pathophysiology, and Clinical Outcomes

The past 3 decades have been characterized by an exponential growth in knowledge and advances in the clinical treatment of atrial fibrillation (AF). It is now known that AF genesis requires a vulnerable atrial substrate and that the formation and composition of this substrate may vary depending on comorbid conditions, genetics, sex, and other factors. Population-based studies have identified numerous factors that modify the atrial substrate and increase AF susceptibility. To date, genetic studies have reported 17 independent signals for AF at 14 genomic regions. Studies have established that advanced age, male sex, and European ancestry are prominent AF risk factors. Other modifiable risk factors include sedentary lifestyle, smoking, obesity, diabetes mellitus, obstructive sleep apnea, and elevated blood pressure predispose to AF, and each factor has been shown to induce structural and electric remodeling of the atria. Both heart failure and myocardial infarction increase risk of AF and vice versa creating a feed-forward loop that increases mortality. Other cardiovascular outcomes attributed to AF, including stroke and thromboembolism, are well established, and epidemiology studies have championed therapeutics that mitigate these adverse outcomes. However, the role of anticoagulation for preventing dementia attributed to AF is less established. Our review is a comprehensive examination of the epidemiological data associating unmodifiable and modifiable risk factors for AF and of the pathophysiological evidence supporting the mechanistic link between each risk factor and AF genesis. Our review also critically examines the epidemiological data on clinical outcomes attributed to AF and summarizes current evidence linking each outcome with AF.

Major Bleeding Complications and Persistence With Oral Anticoagulation in Non-Valvular Atrial Fibrillation: Contemporary Findings in Real-Life Danish Patients

BACKGROUND

The nonvitamin K antagonist oral anticoagulants have recently become available as an alternative to warfarin as stroke prophylaxis in atrial fibrillation, but data on real-life patient experience, including bleeding risk, are lacking. Our objective was to compare major bleeding events and nonpersistence between the nonvitamin K antagonist oral anticoagulant apixaban and other nonvitamin K antagonist oral anticoagulants (dabigatran and rivaroxaban) and warfarin in a contemporary, nation-wide cohort of patients with nonvalvular atrial fibrillation.

METHODS AND RESULTS

Of 54 321 patients (median age, 73 years; 56% male; mean CHA₂DS₂-VASc score, 2.9), 7963, 6715, 15 413, and 24 230 patients initiated apixaban, rivaroxaban, dabigatran, and warfarin, respectively. Apixaban and rivaroxaban initiators were older, less often male, with higher HAS-BLED and CHA₂DS₂-VASc scores compared with dabigatran and warfarin initiators. A total of 2418 patients (4.5%) experienced a major bleeding event over all available follow-up. In this period, rivaroxaban (hazard ratio [HR] [95% CI], 1.49 [1.27-1.77]), dabigatran (HR, 1.17 [1.00-1.38]), and warfarin (HR, 1.23 [1.05-1.43]) users were significantly more likely to bleed than apixaban users. Findings were similar when restricted to the first 30 days after OAC initiation. Risk of nonpersistence was higher for dabigatran (HR, 1.45 [1.33-1.59]) and warfarin initiators (HR, 1.22 [1.12-1.33]), but not for rivaroxaban initiators (HR, 1.07 [0.96-1.20]) compared with apixaban initiators.

CONCLUSIONS

In a real-world cohort of nonvalvular atrial fibrillation patients, apixaban had a lower adjusted major bleeding risk compared with rivaroxaban, dabigatran, and warfarin. Apixaban had a lower risk of nonpersistence compared with dabigatran and warfarin and similar risk compared with rivaroxaban.

Outcomes Associated With Familial Versus Nonfamilial Atrial Fibrillation: A Matched Nationwide Cohort Study

Background

We examined all‐cause mortality and long‐term thromboembolic risk (ischemic stroke, transient ischemic attack, systemic thromboembolism) in patients with and without familial atrial fibrillation (AF).

Methods and Results

Using Danish nationwide registry data, we identified all patients diagnosed with AF (1995–2012) and divided them into those with familial AF (having a first‐degree family member with a prior AF admission) and those with nonfamilial AF. We paired those with and without familial AF according to age, year of AF diagnosis, and sex in a 1:1 match. Using cumulative incidence and multivariable Cox models, we examined the risk of long‐term outcomes. We identified 8658 AF patients (4329 matched pairs) with and without familial AF. The median age was 50 years (interquartile range 43–54 years), and 21.4% were women. Compared with nonfamilial AF patients, those with familial AF had slightly less comorbid illness but similar overall CHA₂DS₂‐VASc score (P=0.155). Median follow‐up was 3.4 years (interquartile range 1.5–6.5 years). Patients with familial AF had risk of death and thromboembolism similar to those with nonfamilial AF (adjusted hazard ratio 0.91 [95% CI 0.79–1.04] for death and 0.90 [95% CI 0.71–1.14] for thromboembolism).

Conclusions

Although family history of AF is associated with increased likelihood for development of AF, once AF developed, long‐term risks of death and thromboembolic complications were similar in familial and nonfamilial AF patients.

Renal Function and the Risk of Stroke and Bleeding in Patients With Atrial Fibrillation

Background and Purpose—

We sought to determine the risk of stroke/thromboembolism and bleeding associated with reduced renal function in patients with atrial fibrillation and the risk of stroke and bleeding associated with warfarin treatment in specific estimated glomerular filtration rate (eGFR) groups.

Methods—

We conducted a register-based cohort study and included patients discharged with nonvalvular atrial fibrillation from 1997 to 2011 with available eGFR.

Results—

A total of 17 349 patients were identified with eGFR available at baseline. All levels of lower eGFR were associated with higher risk of stroke/thromboembolism and bleeding. Use of warfarin was associated with higher bleeding risk in all eGFR groups; hazard ratios 1.23 (95% confidence interval [CI], 0.97–1.56), 1.26 (95% CI, 1.14–1.40), 1.18 (95% CI, 1.07–1.31), 1.11 (95% CI, 0.87–1.42), 2.01 (95% CI, 1.14–3.54) in patients with eGFR ≥90, 60 to 89, 30 to 59, 15 to 29, and <15 mL/min per 1.73 m 2 , respectively. Use of warfarin was associated with lower risk of stroke/thromboembolism in patients with eGFR ≥15 mL/min per 1.73 m 2 ; hazard ratios 0.57 (95% CI, 0.43–0.76), 0.57 (95% CI, 0.51–0.64), 0.48 (95% CI, 0.44–0.54), 0.60 (95% CI, 0.45–0.80) in patients with eGFR ≥90, 60 to 89, 30 to 59, and 15 to 29 mL/min per 1.73 m 2 , respectively. Use of warfarin was not associated with lower risk of stroke/thromboembolism in patients with eGFR<15 mL/min per 1.73 m 2 ; hazard ratio 1.18 (95% CI, 0.58–2.40).

Conclusions—

In patients with atrial fibrillation, the risk of stroke and bleeding was associated with levels of renal function. Warfarin treatment was associated with higher risk of bleeding in all eGFR groups and lower risk of stroke in patients with eGFR≥15 mL/min per 1.73 m 2 .

Risk of Ischemic Stroke, Hemorrhagic Stroke, Bleeding, and Death in Patients Switching from Vitamin K Antagonist to Dabigatran after an Ablation

Background

Safety regarding switching from vitamin K antagonist (VKA) to dabigatran therapy in post-ablation patients has never been investigated and safety data for this is urgently needed. The objective of this study was to examine if switch from VKA to dabigatran increased the risk of stroke, bleeding, and death in patients after ablation for atrial fibrillation.

Methods

Through the Danish nationwide registries, patients with non-valvular atrial fibrillation undergoing ablation were identified, in the period between August 22nd 2011 and December 31st 2015. The risk of ischemic stroke, hemorrhagic stroke, bleeding, and death, related to switching from VKA to dabigatran was examined using a multivariable Poisson regression model, where Incidence rate ratios (IRR) were estimated using VKA as reference.

Results

In total, 4,236 patients were included in the study cohort. The minority (n = 470, 11%) switched to dabigatran in the follow up period leaving the majority (n = 3,766, 89%) in VKA treatment. The patients in the dabigatran group were older, were more often males, and had higher CHA2DS2-VASc, and HAS-BLED scores. The incident rates of bleeding and death were almost twice as high in the dabigatran group compared with the VKA group. When adjusting for the individual components included in the CHA2DS2-VASc and HAS-BLED scores, the multivariable Poisson analyses yielded a non-significant IRR (95%CI) of 1.64 (0.72–3.75) for bleeding and of 1.41 (0.66–3.00) for death associated with the dabigatran group, compared to the VKA group. A significant increased risk of bleeding was found in the 110mg bid group with an IRR (95%CI) of 4.49(1.40–14.5).

Conclusion

Shifting from VKA to dabigatran after ablation was associated with twice as high incidence of bleeding compared to the incidence in patients staying in VKA treatment. The only significant increased risk found in the adjusted analyses was for bleeding with 110mg bid dabigatran and not for 150mg bid. Since there was no dose-response for bleeding, the switch from VKA to dabigatran in itself was not a risk factor for bleeding.

Non-vitamin K antagonist oral anticoagulation usage according to age among patients with atrial fibrillation: Temporal trends 2011-2015 in Denmark

Among atrial fibrillation (AF) patients, Danish nationwide registries (2011–2015) were used to examine temporal trends of initiation patterns of oral anticoagulation (OAC) treatment according to age. Overall, 43,299 AF patients initiating vitamin K antagonists (VKA) (42%), dabigatran (29%), rivaroxaban (13%), or apixaban (16%) were included with mean age (SD) 72.1 (11.3), 71.5 (11.0), 74.3 (11.1), and 75.3 (11.1) years, respectively. Patients aged ≥85 years comprised 15%. Trend tests showed increase in patients ≥85 years initiating OAC (p < 0.0001). VKA usage decreased from 92% to 24% (p < 0.0001). This decrease was independent of age. Dabigatran was the most common non-VKA OAC (NOAC) (40% users), but usage decreased from 2014 until study end (6%) (p < 0.0001). Apixaban was the most used OAC at study end (41%), in particular among those ≥85 years (44%). Compared with patients aged <65 years, the odds ratios associated with initiating VKA, dabigatran, rivaroxaban, or apixaban for patients aged ≥85 years were 0.81 (95% CI 0.75–0.86), 0.65 (95% CI 0.60–0.70), 1.52 (95% CI 1.38–1.67), and 2.09 (95% CI 1.89–2.30), respectively. In conclusion, substantial increase in NOAC usage has occurred. Increasing age was associated with upstart of rivaroxaban or apixaban with reference to age <65 within the specific agent.

Stroke and recurrent haemorrhage associated with antithrombotic treatment after gastrointestinal bleeding in patients with atrial fibrillation: nationwide cohort study

STUDY QUESTION

What are the risks of all cause mortality, thromboembolism, major bleeding, and recurrent gastrointestinal bleeding associated with restarting antithrombotic treatment after gastrointestinal bleeding in patients with atrial fibrillation?

METHODS

This Danish cohort study (1996-2012) included all patients with atrial fibrillation discharged from hospital after gastrointestinal bleeding while receiving antithrombotic treatment. Restarted treatment regimens were single or combined antithrombotic drugs with oral anticoagulation and antiplatelets. Follow-up started 90 days after discharge to avoid confounding from use of previously prescribed drugs on discharge. Risks of all cause mortality, thromboembolism, major bleeding, and recurrent gastrointestinal bleeding were estimated with competing risks models and time dependent multiple Cox regression models.

STUDY ANSWER AND LIMITATIONS

4602 patients (mean age 78 years) were included. Within two years, 39.9% (95% confidence interval 38.4% to 41.3%, n=1745) of the patients had died, 12.0% (11.0% to 13.0%, n=526) had experienced thromboembolism, 17.7% (16.5% to 18.8%, n=788) major bleeding, and 12.1% (11.1% to 13.1%, n=546) recurrent gastrointestinal bleeding. 27.1% (n=924) of patients did not resume antithrombotic treatment. Compared with non-resumption of treatment, a reduced risk of all cause mortality was found in association with restart of oral anticoagulation (hazard ratio 0.39, 95% confidence interval 0.34 to 0.46), an antiplatelet agent (0.76, 0.68 to 0.86), and oral anticoagulation plus an antiplatelet agent (0.41, 0.32 to 0.52), and a reduced risk of thromboembolism was found in association with restart of oral anticoagulation (0.41, 0.31 to 0.54), an antiplatelet agent (0.76, 0.61 to 0.95), and oral anticoagulation plus an antiplatelet agent (0.54, 0.36 to 0.82). Restarting oral anticoagulation alone was the only regimen with an increased risk of major bleeding (1.37, 1.06 to 1.77) compared with non-resumption of treatment; however, the difference in risk of recurrent gastrointestinal bleeding was not significant between patients who restarted an antithrombotic treatment regimen and those who did not resume treatment.

WHAT THIS STUDY ADDS

Among patients with atrial fibrillation who experience gastrointestinal bleeding while receiving antithrombotic treatment; subsequent restart of oral anticoagulation alone was associated with better outcomes for all cause mortality and thromboembolism compared with patients who did not resume treatment. This was despite an increased longitudinal associated risk of bleeding.

FUNDING, COMPETING INTERESTS, DATA SHARING

This study was supported by a grant from Boehringer-Ingelheim. Competing interests are available in the full paper on bmj.com. The authors have no additional data to share.