P1564Atrial fibrillation and thromboembolic prophylaxis: focus on the frail oldest patient. how net clinical benefit influences anticoagulant therapy

Background

Atrial fibrillation is highly prevalent among the elderly population, which is also frequently prone to thromboembolic complications. Anticoagulant prophylaxis is underused in the elderly due to fear of bleeding, which tends to be more frequent and severe within this group. Randomized controlled trials and several observational studies have shown the comparative effectiveness of direct oral anticoagulant (DOAC) against vitamin K antagonists (VKA), and their superior safety, at least in terms of intracranial bleeding. However, for patients aged 85 or older, there is still insufficient literature, leaving unanswered the question of which prophylaxis to use.

Purpose

The aim of the study is to compare the incidence of established outcomes and to investigate the net clinical benefit between DOAC and VKA in patients aged ≥85 years.

Methods

A cohort of 553 outpatients from the real world began treatment using DOACs at our clinic. The prospective follow-up on average lasted 1.97 years. Main endpoints were stroke and systemic thromboembolism, major hemorrhage, myocardial infarction and mortality for all causes. A sample of the 160 patients aged ≥85 years was compared with the remaining younger ones and with a second cohort of 298 outpatients aged ≥85 years. Retrospectively analyzed, with follow-ups at our center, who started VKAs; the average time was 2.03 years. The “net clinical benefit” of DOACs against VKAs was calculated as the difference between thromboembolic events with VKAs and with DOACs, minus the difference (weighted by 1.5) between spontaneous intracranial bleeding with DOACs and VKAs.

Results

In terms of thromboembolic events, DOACs and VKAs (2.43% p-y vs. 1.82% p-y, p=0.975) have shown comparable efficacy in a higher risk sample (CHA2DS2-VASc score: 5.2 vs. 4.5; p<0.001). There were no differences in spontaneous intracranial hemorrhages (0.81% p-y vs. 1.16% p-y; p=0.419). Major bleeding was more frequent in DOACs (10.11% p-y vs. 4.13% p-y, p<0.05), although they are comparable if we consider patients in VKAs achieving a time in therapeutic range (TTR) <60%. Mortality, in all cases similar (13.75% p-y vs. 9.92% p-y; p=0.778), but was reduced in patients with VKAs therapy, with a TTR ≥60%. The net clinical benefit of DOACs compared to VKAs is noticeable in patients with a previous stroke or with CHA2DS2-VASc score <6, while VKAs may be more beneficial to patients with vascular disease or with CHA2DS2-VASc score ≥6.

Conclusions

DOACs are as effective in very old patients with atrial fibrillation compared to very old patients receiving VKAs, but they are associated with increased major bleeding. The same is true when compared with younger DOACs users. TTR, representing quality achieved by the anticoagulation with a VKA, can influence the comparison with DOACs. Considering ischemic strokes and spontaneous intracranial hemorrhages, there is however a net benefit for DOACs use in specific categories of elderly patients.

P6258Direct oral anticoagulants in non-valvular atrial fibrillation: accuracy of traditional bleeding scores in the elderly

Background

Due to the fear of increased risk of bleeding, anticoagulation treatment is underutilized in the prevention of stroke in elderly patients with non-valvular atrial fibrillation (NVAF). Although direct oral anticoagulants (DOAC) are safer than VKA, still little is known about the risk factors associated with bleeding in elderly patients treated with DOAC. Furthermore, it is still uncertain whether the risk scores that are currently used can serve to effectively identify higher bleeding risk in elderly subjects.

Purpose

The aim of this study was to identify predictors of bleeding in a cohort of elderly people affected by NVAF treated with DOAC, and to evaluate the accuracy of risk scores for bleeding used at present.

Methods

Data on outpatients aged ≥75 years, naïve for DOAC therapy, who started therapy with Dabigatran, Rivaroxaban, Apixaban or Edoxaban for the prevention of thromboembolism during FANV were analyzed. HASBLED, ATRIA, OBRI and ORBIT scores were calculated for each patient. Patients had follow-up for 12 months during which deaths, therapy discontinuation and adverse events such as thromboembolism and bleeding were reported. Potential predictors of bleeding and the predictive value of each bleeding score were tested using univariate Cox regression; testing accuracy was evaluated using ROC curves.

Results

A total of 291 patients (52.9% female, mean age 82.85±5.18 years) had a median follow-up time of 11 (10–12) months. The incidence rate of major bleeding was 4.7 per 100 patient-years, the rate of intracranial bleeding was 0.4 per 100 patient-years. Patients who had major bleeding were more often affected by heart failure (63.6% vs 25%; p=0.009) and thrombocytopenia (36.4% vs 7.4%; p=0,009). However in the multivariate analysis only heart failure remained statistically associated with major bleeding (HR 3.83, 95% CI 1.06–13.85; p=0.041). None of tested bleeding risk scores was able to predict major bleeding in our cohort. HASBLED and ORBIT scores were able to predict major and non-major clinically relevant bleeding (HR 1.32; 95% CI 1.01–1.71; p=0.042 and HR 1.20; 95% CI 1.00- 1.43; p=0.046); only the ORBIT score was found to be statistically significant, but with weak discriminatory power at ROC curves (AUC 0.59; 95% CI 0.51–0.68; p=0.041).

Conclusions

In our cohort of elderly patients aged 75 or older, anticoagulated for NVAF, heart failure history was the only effective predictor of major bleeding risk during DOAC treatment. None of the bleeding risk scores used currently have demonstrated a good discriminatory power in our cohort. As predictive factors of bleedings in DOAC-treated patients may not be the same as those for VKA-treated patients and those in elderly may also be differ in younger people, it calls for more investigation on the topic.

Consequences of warfarin suspension after major bleeding in very elderly patients with non valvular atrial fibrillation

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

Anthropometric parameters and the incidence of atrial fibrillation in older people: the PRO.V.A study

BACKGROUND

Atrial fibrillation (AF) has been associated with body size and central obesity, but the impact of different anthropometric measures in this relationship has been inadequately investigated.

HYPOTHESIS

In this study, we examined the association between baseline anthropometric parameters with the incidence of AF in older people, hypothesizing that body size could impact the onset of AF more than fat distribution.

METHODS

Our study included 1764 participants with a mean age of 74.3 ± 6.9 years and no AF at baseline. Body mass index (BMI), body height, body surface area (BSA), waist and hip circumference, waist-to-stature ratio, waist-to-hip ratio, and mid-upper arm circumference (MUAC) were measured by trained physicians. AF was assessed after a 4.4-year follow-up.

RESULTS

There were 115 new cases of AF observed after the follow-up. Taking lower values of these measures for reference, the adjusted AF risk was 2.42 (95% confidence interval [CI]:1.88-3.12) for the highest stature quartile, 1.36 (95% CI:1.15-1.62) for BMI ≥30 kg/m2 , 2.12 (95% CI:1.73-2.59) for the highest BSA quartile, 1.38 (95% CI: 1.21-1.56) for higher MUAC, and 1.39 (95% CI: 1.23-1.58, P < 0.0001) for higher hip circumference values. Central obesity did not seem to relevantly predict the onset of AF in our sample. Stature revealed the strongest impact on the onset of AF (5% higher risk of developing AF per 1 cm increase in height).

CONCLUSIONS

Body size, particularly tall stature and obesity, but not fat distribution, seems to be associated with the risk of AF in the elderly.

Impact of residual pulmonary obstruction on the long-term outcome of patients with pulmonary embolism

The impact of residual pulmonary obstruction on the outcome of patients with pulmonary embolism is uncertain.We recruited 647 consecutive symptomatic patients with a first episode of pulmonary embolism, with or without concomitant deep venous thrombosis. They received conventional anticoagulation, were assessed for residual pulmonary obstruction through perfusion lung scanning after 6 months and then were followed up for up to 3 years. Recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension were assessed according to widely accepted criteria.Residual pulmonary obstruction was detected in 324 patients (50.1%, 95% CI 46.2-54.0%). Patients with residual pulmonary obstruction were more likely to be older and to have an unprovoked episode. After a 3-year follow-up, recurrent venous thromboembolism and/or chronic thromboembolic pulmonary hypertension developed in 34 out of the 324 patients (10.5%) with residual pulmonary obstruction and in 15 out of the 323 patients (4.6%) without residual pulmonary obstruction, leading to an adjusted hazard ratio of 2.26 (95% CI 1.23-4.16).Residual pulmonary obstruction, as detected with perfusion lung scanning at 6 months after a first episode of pulmonary embolism, is an independent predictor of recurrent venous thromboembolism and/or chronic thromboembolic pulmonary hypertension.

Reasons for and consequences of vitamin K antagonist discontinuation in very elderly patients with non-valvular atrial fibrillation

Essentials Anticoagulation in the elderly is still a challenge and suspension of warfarin is common. This is an observational study reporting reasons and consequences of warfarin suspension. Vascular disease, age, time in therapeutic range, and bleedings are associated with suspension. After suspension for bleeding or frailty, patients remain at high-risk of death or complications.

SUMMARY

Background Anticoagulation in elderly patients with non-valvular atrial fibrillation (NVAF) is still a challenge, and discontinuation of warfarin is common. The aim of this study was to analyze the aspects related to warfarin discontinuation in a real-world population. Methods This was an observational cohort study on very elderly NVAF patients naive to warfarin therapy (VENPAF). The included subjects were aged at least 80 years, and started using warfarin after a diagnosis of NVAF. Warfarin discontinuation was assessed, and the reason reported for discontinuation, the person who decided to stop treatment, subsequent antithrombotic therapy and mortality, ischemic and bleeding events were collected. Results Over a period of 5 years, warfarin was discontinued in 148 of 798 patients. Despite similar CHA2 DS2 -VASc scores, the frequencies of thromboembolic and major bleeding events were significantly higher (P = 0.01 and P = 0.001, respectively) and the time in therapeutic range (TTR) was significantly lower (P < 0.001) in patients who discontinued warfarin. Independent risk factors for warfarin discontinuation were vascular disease (hazard ratio [HR] 2.5, P < 0.001), age ≥ 85 years (HR 1.4, P = 0.04), TTR < 60% (HR 1.8, P = 0.001), and bleeding events (HR 2.3, P < 0.001). The main reasons for warfarin discontinuation were physician-perceived frailty or low life-expectancy (45.9%), bleeding complications (19.6%), and sinus rhythm restoration (16.9%). Event and death rates were very high, especially in frail patients and in those with bleeding complications. Conclusions Warfarin discontinuation is frequent in very elderly patients, and is associated with increased risks of death and adverse events. Identification of elderly patients who are at high risk of bleeding and the poor quality of anticoagulation during warfarin are still unsolved clinical problems.

A Randomized Trial of Pharmacogenetic Warfarin Dosing in Naïve Patients with Non-Valvular Atrial Fibrillation

Genotype-guided warfarin dosing have been proposed to improve patient’s management. This study is aimed to determine whether a CYP2C9- VKORC1- CYP4F2-based pharmacogenetic algorithm is superior to a standard, clinically adopted, pharmacodynamic method. Two-hundred naïve patients with non-valvular atrial fibrillation were randomized to trial arms and 180 completed the study. No significant differences were found in the number of out-of-range INRs (INR<2.0 or >3.0) (p = 0.79) and in the mean percentage of time spent in the therapeutic range (TTR) after 19 days in the pharmacogenetic (51.9%) and in the control arm (53.2%, p = 0.71). The percentage of time spent at INR>4.0 was significantly lower in the pharmacogenetic (0.7%) than in the control arm (1.8%) (p = 0.02). Genotype-guided warfarin dosing is not superior in overall anticoagulation control when compared to accurate clinical standard of care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01178034.

To treat or not to treat very elderly naïve patients with atrial fibrillation with vitamin K antagonists (VKA): results from the VENPAF cohort

Despite the recommendations in the guidelines, physicians still underuse warfarin in very elderly patients with non-valvular atrial fibrillation (NVAF). The risks of stroke and major bleeding both increase with age, but it is still not clear whether the beneficial effects of vitamin K antagonists (VKA) in preventing stroke outweigh the related bleeding risks in fragile, very elderly patients. The bleeding rates reported in real-world observational studies differ considerably. The aim of this study was to retrospectively assess the incidence of major bleeding in VKA-naïve patients over 80 years old with NVAF at a large anticoagulation clinic. Significant predictors of major bleeding were also investigated. Sixty-five major bleeding events (3.4 per 100 patient-years) and 25 thromboembolic events (1.3 per 100 patient-years) were recorded in a sample of 798 patients with a median follow-up of 2.2 years. Patients over 85 years old had significantly more major bleeding events than the 80- to 84-year olds (4.7 vs. 2.6 per 100 patient-years, p 0.014). Spontaneous bleeding was also significantly more common (3.0 vs. 1.3 per 100 patient-years, p 0.008) in the very elderly group. Age and diabetes were the only independent risk factor for bleeding on multivariate Cox analysis (Age HR 1.80, 95% CI 1.10-2.93; diabetes HR 1.76, 95% CI 1.00-3.09). These data show a sharp increase in major bleeding episodes among the very elderly with atrial fibrillation. Further studies are warranted with a view to identifying patients at risk.

Standardized low-molecular-weight heparin bridging regimen in outpatients on oral anticoagulants undergoing invasive procedure or surgery: an inception cohort management study

BACKGROUND

Bridging therapy with low-molecular-weight heparin is usually recommended in patients who must stop oral anticoagulants before surgical or invasive procedures. To date, there is no universally accepted bridging regimen tailored to the patient's thromboembolic risk. This prospective inception cohort management study was designed to assess the efficacy and safety of an individualized bridging protocol applied to outpatients.

METHODS AND RESULTS

Oral anticoagulants were stopped 5 days before the procedure. Low-molecular-weight heparin was started 3 to 4 days before surgery and continued for 6 days after surgery at 70 anti-factor Xa U/kg twice daily in high-thromboembolic-risk patients and prophylactic once-daily doses in moderate- to low-risk patients. Oral anticoagulation was resumed the day after the procedure with a boost dose of 50% for 2 days and maintenance doses afterward. The patients were followed up for 30 days. Of the 1262 patients included in the study (only 15% had mechanical valves), 295 (23.4%) were high-thromboembolic-risk patients and 967 (76.6%) were moderate- to low-risk patients. In the intention-to-treat analysis, there were 5 thromboembolic events (0.4%; 95% confidence interval, 0.1 to 0.9), all in high-thromboembolic-risk patients. There were 15 major (1.2%; 95% confidence interval, 0.7 to 2.0) and 53 minor (4.2%; 95% confidence interval, 3.2 to 5.5) bleeding episodes. Major bleeding was associated with twice-daily low-molecular-weight heparin administration (high-risk patients) but not with the bleeding risk of the procedure.

CONCLUSIONS

This management bridging protocol, tailored to patients' thromboembolic risk, appears to be feasible, effective, and safe for many patients, but safety in patients with mechanical prosthetic valves has not been conclusively established.

Facioscapulohumeral muscular dystrophy and occurrence of heart arrhythmia

BACKGROUND

Subjects with facioscapulohumeral muscular dystrophy (FSHD) do not generally suffer from significant cardiac symptoms. Although with heterogeneous results, studies reported to date indicate that heart alterations unrelated to cardiomyopathy are possible in FSHD.

PATIENTS AND METHODS

We describe the findings of a multicenter investigation aimed at detecting cardiac abnormalities in 83 FSHD patients, 44 males and 39 females with a mean age of 47 years. All patients underwent clinical heart examination, 12-lead electrocardiography and 24-hour Holter monitoring; echocardiography was also performed on most patients.

RESULTS

Among the 83 patients, 62 with no cardiovascular risk factors were identified. Ten of them manifested clinical or subclinical cardiac involvement: 5 reported symptoms represented mostly by frequent palpitations secondary to supraventricular arrhythmia and another 5 exhibited electrocardiographic signs of short runs of supraventricular paroxysmal tachycardia. In the absence of cardiovascular risk factors, we found symptoms or signs of heart involvement of mainly arrhythmic origin in 10 of our 83 FSHD patients (12%).

CONCLUSIONS

Considering our data and those available in the literature as a whole, arrhythmic alterations seem to be detected more frequently than expected in FSHD patients.

Effectiveness of fixed minidose warfarin in the prevention of thromboembolism and vascular death in nonrheumatic atrial fibrillation

Adjusted-dose warfarin is effective for stroke prevention in patients with nonrheumatic atrial fibrillation (AF), but the risk of bleeding is high, especially among the elderly. Fixed minidose warfarin is effective in preventing venous thromboembolism with low risk of bleeding and no need for frequent clinical monitoring. Patients > 60 years with nonrheumatic AF were randomized in an open-labeled trial to receive fixed minidose warfarin (1.25 mg/day) or standard adjusted-dose warfarin (International Normalized Ratio [INR] between 2.0 and 3.0). Primary outcome events were ischemic stroke, peripheral or visceral embolism, cerebral or fatal bleeding, and vascular death. Secondary end points were major bleeding, myocardial infarction, and death. This study was discontinued before completion in light of publication of the Stroke Prevention in Atrial Fibrillation III trial, which indicated that low-intensity fixed-dose warfarin treatment (i.e., INR < 1.5) was insufficient for stroke prevention in high-risk patients with nonrheumatic AF. From a total of 1,209 considered patients, 303 were randomized to be studied (150 in the minidose group and 153 in the adjusted-dose group). Mean follow-up was 14.5 months. The rate of cumulative primary events was 11.1% (95% confidence intervals [CI] 4.0 to 18.2) in the fixed minidose group and 6.1% (95% CI 1.1 to 11.1) in the adjusted-dose group (p = 0.29). The rate of ischemic stroke was significantly higher in the minidose group (3.7% vs 0% per year, p = 0.025). Major bleedings were more frequent in standard treatment group (2.6% vs 1% per year, p = 0.19). Most thromboembolic complications occurred at INRs < 1.2, whereas the majority of hemorrhages occurred at INRs > 3.0. No significant difference in primary outcome events was observed in the abbreviated study. However, the significantly increased occurrence of ischemic stroke in the fixed minidose warfarin group suggests that this regimen does not protect patients with nonrheumatic AF.