Ankle brachial index as an independent predictor of mortality in anticoagulated atrial fibrillation

Another possible determinant for ischemic stroke with nonvalvular atrial fibrillation other than conventional oral anticoagulant treatment: The relationship between whole blood viscosity and stroke☆

OBJECTIVES

Patients with nonvalvular atrial fibrillation (NVAF) still experience ischemic stroke despite recommended medications and this could be the consequence of increased whole blood viscosity (WBV). We evaluated the predictive value of WBV for stroke in patients with NVFA despite receiving oral anticoagulant (OAC) therapy.

METHODS

One thousand and forty-three NVAF patients on OAC medication were followed up for median 36.13 ± 18.31 months. WBV was calculated according to the validated de Simone's formula.

RESULTS

WBV was significantly higher in stroke group when compared to non-stroke group at both low shear rate (LSR) and high shear rate (HSR). Multiple regression analysis demonstrated an independent association between WBV and stroke when adjusted for other risk factors.

CONCLUSIONS

WBV appears to be a profitable predictor of ischemic stroke in patients with NVAF receiving OAC.

The Impact of Atrial Fibrillation on Outcomes of Peripheral Arterial Disease: Analysis of Routinely Collected Primary Care Data

BACKGROUND

The combination of peripheral arterial disease and atrial fibrillation is linked with high risk of mortality and stroke. This study aims to investigate the impact of atrial fibrillation on patients with diagnosed peripheral arterial disease.

METHODS

This is a retrospective study using The Health Improvement Network database, which contains prospectively collected data from participating primary care practices. Patients with a new diagnosis of peripheral arterial disease between January 8, 1995 and January 5, 2017 were identified in the database alongside relevant demographic information, clinical history, and medications. Every patient in the dataset with peripheral arterial disease and baseline atrial fibrillation (case) was matched to a patient without atrial fibrillation (control) with similar characteristics using propensity score matching. Cox-regression analysis was performed and hazard ratios (HR) calculated for the outcomes of death, stroke, ischemic heart disease, heart failure, and major amputation.

RESULTS

Prevalence of atrial fibrillation in this cohort was 10.2%. All patients with peripheral arterial disease and atrial fibrillation (n = 5685) were matched with 5685 patients without atrial fibrillation but otherwise similar characteristics. After multivariate analysis, atrial fibrillation was independently associated with mortality (HR 1.18; 95% confidence interval [CI], 1.12-1.26; P < .01), cerebrovascular events (HR 1.35; 95% CI, 1.17-1.57; P < .01), and heart failure (HR 1.87; 95% CI, 1.62-2.15; P < .01), but not with ischemic heart disease or limb loss.

CONCLUSION

In peripheral arterial disease patients, atrial fibrillation is a risk factor for mortality, stroke, and heart failure. This emphasizes the need for proactive surveillance and holistic management of these patients.

Peripheral Arterial Disease in Patients with Atrial Fibrillation: The AFFIRM Study

BACKGROUND

Peripheral arterial disease has been linked with worse outcomes in patients with atrial fibrillation. The aim of this study is to assess the impact of peripheral arterial disease on mortality and stroke in a cohort of patients with atrial fibrillation.

METHODS

This was an ancillary analysis of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. A comparison of baseline characteristics was made between patients with atrial fibrillation with and without diagnosed peripheral arterial disease. Multivariate cox regression analysis was performed to compare the risk of stroke, death, and cardiovascular death among the two groups.

RESULTS

The prevalence of peripheral arterial disease in the whole cohort of 4060 patients with atrial fibrillation was 6.7%. Patients with peripheral arterial disease tended to be older; had higher prevalence of diabetes mellitus, hypertension, and smoking; and were more likely to have a history of coronary artery disease, heart failure, cardiac surgery or cardiac intervention, and stroke or transient ischemic attack (all P < .05). After multivariate adjustment, peripheral arterial disease was significantly associated with overall higher mortality (hazard ratio 1.34, 95% confidence interval 1.06-1.70, P = .016) in patients with atrial fibrillation, but the rates of ischemic stroke were similar in the two groups (3.9% vs 3.5%, P = 0.874). Subgroup analysis confined to the patients with non-anticoagulated atrial fibrillation showed that peripheral arterial disease was an independent predictor of ischemic stroke (hazard ratio 3.37, 95% confidence interval 1.25-9.09, P < .016).

CONCLUSION

Peripheral arterial disease predicts higher mortality in atrial fibrillation, and was an independent predictor of ischemic stroke in patients with non-anticoagulated atrial fibrillation. Proactive surveillance and optimization of medical management in this group of patients is warranted, given the high risks associated with peripheral arterial disease where atrial fibrillation is also present.

Relationship of peripheral and coronary artery disease to cardiovascular events in patients with atrial fibrillation

BACKGROUND

To investigate the impact of concomitant asymptomatic peripheral artery disease (PAD) and pre-existing coronary artery disease (CAD) on cardiovascular events (CVEs) in atrial fibrillation (AF) patients.

METHODS

Prospective multicenter study including 1138 anticoagulated AF patients. PAD was diagnosed by can ankle-brachial index (ABI)≤0.9, and CAD as a documented myocardial infarction (MI) or cardiac revascularization. The cohort was divided into 4 groups: group 0 (n=717) with no previous CAD and ABI >0.9; group 1 (n=168) no previous CAD and ABI≤0.9; group 2 (n=183) previous CAD and ABI >0.9: and group 3 (n=70) previous CAD and ABI≤0.9. The primary endpoint was a composite of CVEs.

RESULTS

Mean age was 72.6years and 41.3% were female. History of CAD was present in 253 (22.2%) patients, and 238 (20.9%) had an ABI≤0.9. Patients with previous CAD were more likely to have a low ABI compared to those without (OR:1.6, 95%CI 1.2-2.3, P=0.003). Median follow-up was 35.9months (IQR 19.2-57.2, 3819 patient-years), and 145 CVEs were recorded (3.8%/year 95%CI 3.2-4.5). Survival analysis showed a progressive increase in the rate of CVEs in the four groups (log-rank test P<0.001). Multivariable Cox regression analysis showed that as compared to group 0, group 1 (HR:1.8, 95%CI 1.1-2.9, P=0.01), group 2 (HR:2.2, 95%CI 1.4-3.4, P=0.001) and group 3 (HR:2.4, 95%CI 1.4-4.4, P=0.003) were associated with progressive greater risk of CVEs.

CONCLUSION

Patients with concomitant CAD and asymptomatic PAD are at high risk of CVEs, with a progressive risk with vascular disease burden where PAD was associated with CAD.

Direct oral anticoagulants and cardiovascular prevention in patients with nonvalvular atrial fibrillation

INTRODUCTION

Patients with atrial fibrillation have an increased risk for stroke, systemic embolism and cardiovascular events, including myocardial infarction and cardiovascular death. However, the majority of studies that have analyzed the efficacy of anticoagulants have been focused only on their effects on the risk of stroke. Areas covered: The available evidence about the association between atrial fibrillation and cardiovascular disease as well as the effects of oral anticoagulation on cardiovascular death and myocardial infarction, with a particular focus on direct oral anticoagulants, was updated in this review. Expert opinion: The management of patients with atrial fibrillation should not be limited to the prevention of stroke, but should also include the prevention of cardiovascular events. Despite treatment with vitamin K antagonists, many patients with atrial fibrillation still develop cardiovascular complications, particularly individuals whose anticoagulation is difficult to control. Direct oral anticoagulants overcome the majority of limitations of vitamin K antagonists and compared with warfarin, they lead to a greater reduction in the risk of stroke or systemic embolism, all-cause mortality, and intracranial hemorrhage. Although these drugs can only be compared indirectly, it seems that not all direct oral anticoagulants are equal with regard to the prevention of myocardial infarction.

Association of Brachial-Ankle Pulse Wave Velocity With Cardiovascular Events in Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) and increased arterial stiffness share several risk factors and the 2 diseases often coexist. However, the prognostic value of increased arterial stiffness remains uncertain in the AF population. We evaluated whether brachial-ankle pulse wave velocity (baPWV), a marker of arterial stiffness, can predict cardiovascular events, and determined that the baPWV is a more favorable prognostic marker compared with conventional clinical and echocardiographic markers in patients with AF.

METHODS

We enrolled 167 patients with persistent AF. Arterial stiffness was assessed using baPWV. Cardiovascular events were defined as cardiovascular death, nonfatal stroke, nonfatal myocardial infarction, and hospitalization for heart failure. The relative risk of cardiovascular events was analyzed using Cox regression models. An improvement in model prediction was determined using the -2 log likelihood ratio statistic.

RESULTS

During a median 26-month follow-up, 42 (24.9%) cardiovascular events were observed. The baPWV emerged as an independent predictor of cardiovascular events (adjusted hazard ratio: 1.152; 95% confidence interval: 1.054-1.259; P = 0.002) in the multivariate analysis. Furthermore, the addition of baPWV to a Cox model comprising standard clinical, biochemical, and echocardiographic parameters improved the prediction of adverse cardiovascular events (P < 0.001).

CONCLUSIONS

In patients with AF, a high baPWV is associated with increased cardiovascular events and improve the prediction of adverse cardiovascular events. Hence, baPWV might be included when examining patients with AF for prediction of adverse cardiovascular outcomes.

CHADS2 Score and Risk of New-onset Peripheral Arterial Occlusive Disease in Patients without Atrial Fibrillation: A Nationwide Cohort Study in Taiwan

AIM

Although our recent cross-sectional study demonstrated that the CHADS2 score is associated with an ankle-brachial index of ＜ 0.9 in patients without atrial fibrillation (AF), the true cause-effect relationship between these parameters remains to be evaluated. Hence, the aim of this study was to investigate whether the CHADS2 score is a useful predictor of new-onset PAOD in non-AF patients.

METHODS

From January 1, 2000 to December 31, 2001, a total of 723,750 patients older than 18 years of age with no past history of PAOD, rheumatic heart disease or AF were surveyed from the "National Health Insurance Research Database." The CHADS2 score was calculated for each patient. Finally, 581,997 (score 0), 84,971 (score 1), 31,473 (score 2), 14,432 (score 3), 8,156 (score 4), 2,430 (score 5) and 291 (score 6) patients were studied and followed for the onset of PAOD. We further divided the study patients into four groups: group 1 (score 0), group 2 (score 1-2), group 3 (score 3-4) and group 4 (score 5-6).

RESULTS

During the follow-up period of 9.83 ± 0.01 years, 24,775 (3.4%) patients experienced new-onset PAOD. The overall incidence of PAOD was 0.6 per 1,000 patient-years. The rate of PAOD increased from 1.8% (group 1) to 18.7% (group 4) (p ＜ 0.001). According to a multivariate analysis, groups 2-4 were significantly associated with new-onset PAOD (all p ＜ 0.001). In addition, the hazard ratio of each two-point increment in the CHADS2 score for predicting PAOD was 2.51 (p ＜ 0.001).

CONCLUSIONS

The CHADS2 score is a useful predictor of new-onset PAOD in non-AF patients.

How does Chronic Atrial Fibrillation Influence Mortality in the Modern Treatment Era?

Atrial fibrillation (AF) continues to impose a significant burden upon healthcare resources. A sustained increase in the ageing population and better survival from conditions such as ischaemic heart disease have ensured that both the incidence and prevalence of AF continue to increase significantly. AF can lead to complications such as embolism and heart failure and these acting in concert with its associated co-morbidities portend increased mortality risk. Whilst some studies suggest that the mortality risk from AF is due to the "bad company it keeps" i.e. the associated co-morbidities rather than AF itself; undoubtedly some of the mortality is also due to the side-effects of various therapeutic strategies (anti-arrhythmic drugs, bleeding side-effects due to anti-coagulants or invasive procedures). Despite several treatment advances including newer anti-arrhythmic drugs and developments in catheter ablation, anti-coagulation remains the only effective means to reduce the mortality due to AF. Warfarin has been used as the oral anticoagulant in the treatment of AF for many years but suffers from disadvantages such as unpredictable INR levels, bleeding risks and need for haematological monitoring. This has therefore spurred a renewed interest in research and clinical studies directed towards developing safer and more efficacious anti-coagulants. We shall review in this article the epidemiological features of AF-related mortality from several studies as well as the cardiovascular and non-cardiac mortality mechanisms. We shall also elucidate why a rhythm control strategy has appeared to be counter-productive and attempt to predict the likely future impact of novel anti-coagulants upon mortality reduction in AF.

R2CHADS2 score is significantly associated with ankle-brachial index <0.9 in patients without atrial fibrillation

OBJECTIVE

Previous studies demonstrated CHADS2 score and impaired renal function were both associated with ankle-brachial index (ABI) < 0.9 in patients without atrial fibrillation (AF). Hence, we hypothesized the R2CHADS2 score had a significant correlation with ABI < 0.9 and the aim of this study was to validate this association in non-AF patients.

METHODS

A total of 1482 patients without AF were included. ABI was measured using an ABI-form device. Peripheral arterial occlusive disease (PAOD) was defined as ABI < 0.9 in either leg.

RESULTS

Of the 1482 subjects, the prevalence of ABI < 0.9 was 5.6%. Multivariate analysis showed that increased age (odds ratio [OR], 1.049; P < 0.001), decreased estimated glomerular filtration rate (OR, 0.978; P = 0.006), and increased R2CHADS2 score (OR, 1.738; P < 0.001) were associated with ABI < 0.9. In addition, in patients with CHADS2 score ≧ 2, the presence of chronic kidney disease (CKD) was significantly associated with ABI < 0.9 (P ≦ 0.006), but in patients with CHADS2 score < 2, there was no such association (P = 0.357).

CONCLUSIONS

Our study demonstrated R2CHADS2 score was positively correlated with ABI < 0.9. In addition, the presence of CKD was a risk factor of ABI < 0.9 in patients with CHADS2 score ≧ 2. Hence, increased R2CHADS2 score in non-AF patients and the presence of CKD in non-AF patients with CHADS2 score ≧ 2 were useful parameters in identifying the high risk group of PAOD.

Association between the CHADS2 score and an ankle-brachial index of ＜0.9 in patients without atrial fibrillation

AIM

The ankle-brachial index(ABI) is an easy-to-use, non-invasive and reliable diagnostic tool for assessing peripheral arterial occlusive disease(PAOD). The CHADS2(congestive heart failure, hypertension, age ≧75 years, diabetes, prior stroke) score is a simple and popular clinical parameter that is used to assess the risk of stroke in patients with atrial fibrillation (AF). Because all five components of the CHADS2 score are risk factors for PAOD, the score should have a strong correlation with the presence of PAOD. However, there are limited studies regarding the association between the CHADS2 score and PAOD in patients without AF. Therefore, the aim of the present study was to investigate whether the CHADS2 score is positively associated with PAOD in patients without AF.

METHODS

A total of 1,320 patients without AF were included in this study. The ABI was measured using an ABI-form device. PAOD was defined as an ABI of ＜0.9 in either leg.

RESULTS

Among the 1,320 subjects (mean age: 60.3±13.4 years), the prevalence of an ABI of ＜0.9 was 5.7%. A multivariate analysis showed that an increased age(odds ratio [OR], 1.054; p＜0.001), decreased estimated glomerular filtration rate (OR, 0.971; p＜0.001) and increased CHADS2 score (OR, 1.861; p＜0.001) were independently associated with an ABI of ＜0.9.

CONCLUSIONS

Our study demonstrated that the CHADS2 score is significantly associated with an ABI of ＜0.9 in non-AF patients. Further prospective studies are needed to examine the ability of the CHADS2 score to predict the incidence of PAOD.

Cardiovascular morbidity-mortality associated to ankle-brachial index in the general population

BACKGROUND AND OBJECTIVES

Abnormal ankle-brachial index (ABI) is associated with a high risk of cardiovascular disease. This study has aimed to investigate the association between low ABI and risk of cardiovascular death in a general population attended in a primary care center.

PATIENTS AND METHODS

A total of 1,361 volunteers aged between 60 and 79 years without any evidence of peripheral artery disease who attended a primary care center participated in the study. They underwent a complete physical examination, together with standard blood tests and ABI was determined. The participants were contacted by telephone 4 years later and asked about any cardiovascular problems for that period. Causes of death and hospitalization were confirmed in the medical records in the primary care center and/or hospital.

RESULTS

Information was obtained about the clinical evolution of 1,300 participants (mean age 69.9 years, 38.2% men). Mean follow-up was 49.8 months. There were 13 cardiovascular death and 49 major cardiovascular events. Low ABI (<0.9) was associated with a significant higher risk of cardiovascular death (adjusted relative risk 6.83; 95% confidence interval 1.36-34.30, P=.020), and with a higher risk of major cardiovascular events (adjusted relative risk 2.42; 95% confidence interval 0.99-5.91, P=.051). High or uncompressible ABI was not associated with higher cardiovascular risk.

CONCLUSIONS

A low ABI was associated with higher risk of cardiovascular death in the general population followed-up in a primary care center.

The prevalence and influence factors of inter-ankle systolic blood pressure difference in community population

Aim

The aim of this study was to investigate the prevalence of interankle systolic blood pressure difference (sIAND) and its influencing factors in community population.

Methods

This study included 2849 (65.1±9.4 y) subjects. Blood pressure (BPs) of four limbs was simultaneously measured with 4 electronic sphygmomanometers after 10 min rest in supine position. The difference of systolic BP (SBP) between two ankles was calculated as DETASBP. The criterion for abnormal sIAND was ≥10 mmHg of absolute DeltaSBP, in which the criterion for 1o sIAND was 10–19 mmHg and for 2o sIAND was ≥20 mmHg. Age, gender, smoking, hypertension, family histories of hypertension and diabetes were recorded. Fasting blood glucose and lipids, circumference of hip and waist, and body mass index (BMI) were measured.

Results

The SBP was higher in the right ankle than in the left ankle (158.9±21.8 vs 157.3±21.6 mmHg, P<0.05) and mean DeltaSBP was 6.08±6.26 mmHg. Similar difference was found in both genders. The prevalence of abnormal was 18.5%, in which, the prevalence 1o sIAND was 15.3% and that of 2o sIAND was 3.1%. Multivariate regression analysis showed that age, waist circumference and blood glucose level were the positive factors for DeltaSBP. The normal upper limit for DeltaSBP was 16.7 mmHg in this population, the prevalence of sIAND by≥16 mmHg was 5.8%.

Conclusion

Aging, hypertension, obesity and abnormal glucose metabolism are positive factors for inter-ankle SBP difference.

The impact of atherosclerotic vascular disease in predicting a stroke, thromboembolism and mortality in atrial fibrillation patients: a systematic review

BACKGROUND

Atrial fibrillation (AF) is commonly associated with vascular disease. Although atherosclerotic vascular disease (for example, defined as a myocardial infarction (MI), complex aortic plaque and peripheral arterial disease) has been proposed as a risk factor for a stroke, the co-existence of the two diseases increases the risk of future cardiovascular events. The objective of this study was to conduct a systematic review to assess the impact of atherosclerotic vascular disease on the primary end-point of a stroke, thromboembolism or mortality, in patients with AF.

METHODS

Literature searches were performed electronically, to identify studies published between January 1990and July 2012 examining stroke and thromboembolism in relation to AF and atherosclerotic vascular disease. Nineteen articles satisfied the pre-inclusion criteria. The bibliographies were subsequently screened to retrieve further relevant studies for this review.

RESULTS

Peripheral arterial disease significantly increased the stroke risk in all 10 observational studies, within a reported risk range of 1.3- to 2.5-fold. Complex aortic plaque on the descending aorta, as identified by trans-oesophageal echocardiography, was also a significant risk factor. Although a prior myocardial infarction (MI) was validated as a significant predictor of the primary end-point amongst five of the six studies, there was a degree of heterogeneity, owing to the marked difference in population sizes and the use of antithrombotic regimens between studies.

CONCLUSION

Atherosclerotic vascular disease (e.g. peripheral arterial disease, complex aortic plaque and prior MI) are significant predictors of a stroke, thromboembolism and mortality in subjects with AF.