Factors associated with prescription of oral anticoagulation for atrial fibrillation in older people living in care homes in Wales: a routine data linkage study 2003–2018

Background

Prescription of oral anticoagulants (OAC) is paramount for stroke prevention in people with atrial fibrillation (AF), but treatment decisions in older care home residents are complicated by frailty, multi-morbidity and heightened stroke and bleeding risk. There is a paucity of data on factors influencing the decision to prescribe OAC in this high-risk population who are under-represented in research studies.

Purpose

To explore the factors associated with OAC prescription for care home residents aged ≥65 years with AF.

Methods

Nationwide retrospective cohort study of people aged ≥65 years entering a care home in Wales between 1 January 2003 and 31 December 2018, using anonymised individual-level electronic health record and administrative data sources available within the Secure Anonymised Information Linkage Databank. Unadjusted and adjusted logistic regression models were used to explore the association between resident characteristics and OAC prescription or non-prescription.

Results

Between 2003 and 2018, 14,493 people with AF aged ≥65 years became new residents in care homes in Wales and 7,057 (48.7%) were prescribed OAC (32.7% in 2003 compared to 72.7% in 2018), Figure 1. Increasing age and prescription of antiplatelet therapy were associated with lower odds of OAC prescription (adjusted odds ratio [aOR] 0.96 per one year age increase [95% confidence interval, 0.95 to 0.96] and aOR 0.91 [0.84 to 0.98], respectively). Conversely, prior venous thromboembolism (aOR 4.06 [3.17 to 5.20]), advancing frailty (mild: aOR 4.61 [3.95 to 5.38]; moderate: aOR 6.69 [5.74 to 7.80]; severe: aOR 8.42 [7.16 to 9.90]) and year of care home entry in the post-non-vitamin K antagonist oral anticoagulant (NOAC) era from 2011 onwards (aOR 1.91 [1.76 to 2.06]) were associated with higher odds of OAC prescription, Figure 2.

Conclusions

The proportion of care home residents prescribed OAC therapy has increased over time with the introduction of NOACs in 2011, but OAC prescription rates are still sub-optimal. Although there is an expected rise in OAC prescribing for increasingly frail people, further work is needed to investigate the interaction with deprivation and other socio-economic and demographic factors to assess potential inequalities in prescribing across these groups. Targeted educational tools for clinicians are needed to address barriers to OAC prescription for AF, such as older age and separate indications for antiplatelet therapy.

Funding Acknowledgement

Type of funding sources: None.

Prevalence and outcomes of atrial fibrillation in older people living in care homes in Wales: a routine data linkage study 2003–2018

Background

Older care home residents are a high-risk group of people with atrial fibrillation (AF) who are under-represented in clinical trials. Improved understanding of AF epidemiology and management in this population is paramount for health and social care organisations to strategically plan services.

Purpose

To determine the trends in AF prevalence and compare adverse health outcomes in older care home residents aged ≥65 years with AF compared to those without AF.

Methods

Retrospective cohort study of people entering a care home between 2003–2018 using nationwide, population-scale anonymised health and administrative data, provisioned from the Secure Anonymised Information Linkage (1 January 2000–31st December 2018). Direct standardisation was used to calculate AF prevalence by year of care entry (2010–2018). Cox regression analyses were used to estimate the risk of adverse health outcomes.

Results

Between 2003 and 2018, 86,602 people aged ≥65 years became new residents in care homes in Wales. Residents with AF (n=14,493) had a significantly higher risk (adjusted hazard ratio [aHR], 95% confidence interval [CI]) of cardiovascular (aHR 1.27 [1.17 to 1.37], p<0.001) and all-cause mortality (aHR 1.14 [1.11 to 1.17], p<0.001), Figure 1. The risk (sub-distribution hazard ratio [sHR], 95% CI) of ischaemic stroke (adjusted sHR 1.55 [1.36 to 1.76], p<0.001) and cardiovascular hospitalisation (adjusted sHR 1.28 [1.22 to 1.34], p<0.001) was also higher in residents with AF, even when mortality was considered a competing event, Figure 1. There was no significant change in age- and sex-standardised prevalence of AF between 2010 and 2018, 16.79% (95% CI 15.85 to 17.94) and 17.02% (95% CI 16.05 to 17.98), respectively (absolute change 2010–2018: 0.06% [95% CI: −1.38 to 1.50], p=0.93), Figure 2.

Conclusions

This study demonstrates unique data on the epidemiology of AF and associated outcomes in older care home residents. Whilst the prevalence of AF remained stable between 2010–2018, residents with AF had significantly higher risk of adverse health events. Treatment of AF in accordance with guidelines is critical in this population to optimise management and reduce adverse health outcomes.

Funding Acknowledgement

Type of funding sources: None.

Asthma and high-intensity interval training have no effect on clustered cardiometabolic risk or arterial stiffness in adolescents

PURPOSE

Cardiometabolic risk, including arterial stiffness, is increasing in youth. Those with asthma are suggested to be particularly at risk of cardiovascular disease. Efficient and effective strategies are required to prevent the atherosclerotic process in youth. The purpose of this study was to investigate the effect of 6 months high-intensity interval training (HIIT) on cardiometabolic risk in youth with and without asthma.

METHODS

65 adolescents (31 mild asthma; 34 non-asthma) were recruited, 32 (16 asthma) of whom were randomly allocated to receive HIIT three times per week for 6 months. At baseline, mid-intervention, post-intervention and at a 3-month follow-up, anthropometric, metabolic and vascular determinants of cardiometabolic risk were assessed. Following principal component analysis (PCA), linear mixed models were used to assess the influence of asthma, HIIT and their interaction.

RESULTS

Seven factors were identified which explained 88% of the common variance shared among the parameters. Those with asthma demonstrated lower arterial stiffness factor scores mid-intervention (P = 0.047) and lower cholesterol factor scores post-intervention (P = 0.022) but there was no effect of the intervention, or interaction effects, on any PCA-identified factor, at any time-point. HIIT was associated with a lower low-density lipoprotein and diastolic blood pressure at mid-intervention.

DISCUSSION

Neither arterial stiffness nor clustered cardiometabolic risk are influenced by HIIT in adolescents with or without asthma, despite important changes in blood lipid and pressure profiles. Blood pressure, augmentation and pulse wave velocity should be considered physiologically distinct constructs and as potential markers of cardiovascular health.

Can people with type 2 diabetes live longer than those without? A comparison of mortality in people initiated with metformin or sulphonylurea monotherapy and matched, non-diabetic controls

AIMS

Clinical and observational studies have shown an increased risk of cardiovascular events and death associated with sulphonylureas versus metformin. However, it has never been determined whether this was due to the beneficial effects of metformin or detrimental effects of sulphonylureas. The objective of this study was therefore to compare all-cause mortality in diabetic patients treated first-line with either sulphonylurea or metformin monotherapy with that in matched individuals without diabetes.

METHODS

We used retrospective observational data from the UK Clinical Practice Research Datalink (CPRD) from 2000. Subjects with type 2 diabetes who progressed to first-line treatment with metformin or sulphonylurea monotherapy were selected and matched to people without diabetes. Progression to all-cause mortality was compared using parametric survival models that included a range of relevant co-variables.

RESULTS

We identified 78,241 subjects treated with metformin, 12,222 treated with sulphonylurea, and 90,463 matched subjects without diabetes. This resulted in a total, censored follow-up period of 503,384 years. There were 7498 deaths in total, representing unadjusted mortality rates of 14.4 and 15.2, and 50.9 and 28.7 deaths per 1000 person-years for metformin monotherapy and their matched controls, and sulphonylurea monotherapy and their matched controls, respectively. With reference to observed survival in diabetic patients initiated with metformin monotherapy [survival time ratio (STR) = 1.0], adjusted median survival time was 15% lower (STR = 0.85, 95% CI 0.81-0.90) in matched individuals without diabetes and 38% lower (0.62, 0.58-0.66) in diabetic patients treated with sulphonylurea monotherapy.

CONCLUSIONS

Patients with type 2 diabetes initiated with metformin monotherapy had longer survival than did matched, non-diabetic controls. Those treated with sulphonylurea had markedly reduced survival compared with both matched controls and those receiving metformin monotherapy. This supports the position of metformin as first-line therapy and implies that metformin may confer benefit in non-diabetes. Sulphonylurea remains a concern.

Survey of physicians’ practices in the control of cardiovascular risk factors: the EURIKA study

Objectives: To assess the practices of physicians in 12 European countries in the primary prevention of cardiovascular disease (CVD).

Methods: In 2009, 806 physicians from 12 European countries answered a questionnaire, delivered electronically or by post, regarding their assessment of patients with cardiovascular risk factors, and their use of risk calculation tools and clinical practice guidelines (ClinicalTrials.gov number: NCT00882336). Approximately 60 physicians per country were selected (participation rate varied between 3.1% in Sweden and 22.8% in Turkey).

Results: Among participating physicians, 85.2% reported using at least one clinical guideline for CVD prevention. The most popular were the ESC guidelines (55.1%). Reasons for not using guidelines included: the wide choice available (47.1%), time constraints (33.3%), lack of awareness of guidelines (27.5%), and perception that guidelines are unrealistic (23.5%). Among all physicians, 68.5% reported using global risk calculation tools. Written charts were the preferred method (69.4%) and the most commonly used was the SCORE equation (35.4%). Reasons for not using equations included time constraints (59.8%), not being convinced of their usefulness (21.7%) and lack of awareness (19.7%). Most physicians (70.8%) believed that global risk-equations have limitations; 89.8% that equations overlook important risk factors, and 66.5% that they could not be used in elderly patients. Only 46.4% of physicians stated that their local healthcare framework was sufficient for primary prevention of CVD, while 67.2% stated that it was sufficient for secondary prevention of CVD.

Conclusions: A high proportion of physicians reported using clinical guidelines for primary CVD prevention. However, time constraints, lack of perceived usefulness and inadequate knowledge were common reasons for not using CVD prevention guidelines or global CVD risk assessment tools.

How Do We Approach Low High-density Lipoprotein Cholesterol in 2011?

The prevalence of obesity and of the metabolic syndrome is increasing worldwide, and the management of global cardiovascular disease (CVD) risk requires strategies for the treatment of complex, pro-atherogenic dyslipidaemia. Considerable evidence provides a scientific rationale for the role of high-density lipoprotein (HDL) in atheroprotection. Although HDL function can become altered in pathological states, the quantitative evaluation of HDL cholesterol (HDL-C) in addition to total cholesterol (TC) levels improves the accuracy of CVD risk prediction, and is therefore a component of most global CVD risk assessment models. Non-pharmacological lifestyle interventions, such as diet and exercise for weight loss and smoking cessation, are the mainstay of raising HDL in clinical practice. Several HDL-raising medications are available but, beyond statin therapy, evidence of an incremental clinical benefit is limited. Potent novel HDL therapeutics are emerging that not only increase HDL-C levels but may also improve HDL function. Early data have restored some confidence in the potential of new cholesteryl ester transfer protein (CETP) antagonists in clinical practice. It is essential that clinical trials address vascular burden and patient outcomes, and data from large outcome trials are eagerly awaited.

Impact of aortic stenting on peripheral vascular function and daytime systolic blood pressure in adult coarctation

OBJECTIVES

To determine the relation of ambulatory systolic blood pressure to aortic obstruction and more extensive vascular dysfunction, assessed by central aortic, peripheral conduit arterial and resistance vessel function.

METHODS

12 adults (5 native, 7 recoarctation) were studied before, and 2 weeks and 6 months after aortic stenting. Systolic blood pressure was measured during normal daily living by 24-hour ambulatory monitoring. Central aortic function was assessed by pulse wave analysis (augmentation index). Brachial artery flow-mediated dilatation and dilatation in response to 25 mug of sublingual glyceryl trinitrate was assessed by ultrasound to measure peripheral conduit arterial and resistance vessel function. Baseline vascular measures were compared with those of 12 matched controls.

RESULTS

Patients had a higher augmentation index, impaired endothelium-dependent and -independent dilatation, and forearm vascular resistance (p<0.02). After successful gradient relief by stenting, daytime ambulatory systolic blood pressure (151 (134, 166) mm Hg vs 138 (130, 150) mm Hg, p = 0.01) and the augmentation index (26 (15, 34) vs 23 (13, 30), p = 0.03) fell progressively over 6 months, but did not completely normalise. Endothelium-dependent and -independent dilatation, and forearm vascular resistance remained unchanged and impaired.

CONCLUSION

Relief of aortic obstruction is associated with improvement in central aortic function and results in reduction of daytime ambulatory systolic blood pressure. Peripheral vascular dysfunction, however, remains unchanged and may contribute to residual hypertension.

Coronary vasodilation and improvement in endothelial dysfunction with endothelin ET(A) receptor blockade

The endothelium-derived peptide endothelin-1 (ET-1) causes vasoconstriction predominantly via smooth muscle ET(A) receptor activation. We hypothesized that ET(A) receptor inhibition would improve human coronary vascular function. We studied unobstructed coronary arteries of 44 patients with atherosclerosis or its risk factors. Epicardial diameter (D) and Doppler flow velocity were measured, and coronary vascular resistance (CVR) was calculated during intracoronary infusions of acetylcholine (ACH) and sodium nitroprusside (SNP), and during cold pressor testing, before and after a 60-minute intracoronary infusion of the ET(A) receptor antagonist BQ-123. BQ-123 dilated the coronary circulation; D increased by 5.6+/-1.0% (P<0.0001), and CVR fell by 12+/-3% (P<0.01). The D response to ACH, corrected for the SNP response, improved in segments that constricted with ACH at baseline (P=0.03), whereas segments that initially dilated with ACH did not change with BQ-123 (P=NS). Improvement in D and CVR responses to ACH with BQ-123 inversely correlated with baseline ACH responses (r=-0.44 [P=0.006] and r=-0.78 [P=0.001], respectively), indicating greater improvement in those with endothelial dysfunction. Similarly, cold pressor testing-mediated epicardial vasoconstriction (-2.0+/-1.1%) was reversed after BQ-123 (+1.0+/-0.7%), especially in dysfunctional segments (from -5.6+/-0.9% to +2.2+/-0.9%, P<0.001). There was no correlation between any risk factor and the response to BQ-123. An arteriovenous difference in ET-1 levels developed after BQ-123, which was consistent with enhanced cardiac clearance of ET-1, probably via ET(B) receptors. Thus, ET-1 acting via the ET(A) receptor contributes to basal human coronary vasoconstrictor tone and endothelial dysfunction. This suggests that ET(A) receptor antagonism may have therapeutic potential in the treatment of endothelial dysfunction and atherosclerosis.

Angiotensin type 1 receptor antagonism reverses abnormal coronary vasomotion in atherosclerosis

OBJECTIVES

This study was performed to determine whether angiotensin type 1 (AT1) receptor inhibition improves abnormal coronary vasomotion and endothelial dysfunction in patients with atherosclerosis or its risk factors.

BACKGROUND

Endothelial dysfunction, an early feature of atherosclerosis, contributes to abnormal vasomotion during stress. Angiotensin II may contribute to endothelial dysfunction in atherosclerosis.

METHODS

In 25 patients, mean age 59 +/- 2 years, with atherosclerosis or its risk factors, we measured coronary vasomotion during flow-mediated dilation (FMD) in response to adenosine, cold pressor test (CPT) and exercise before and after AT1 receptor blockade with intracoronary losartan (5 mg).

RESULTS

Losartan did not alter resting coronary vascular tone, but epicardial FMD improved from 5.6 +/- 1.5% to 8.9 +/- 1.8% (p = 0.02). Abnormal epicardial vasomotion during CPT and exercise also improved with losartan from -1.7 +/- 0.8% to 1.5 +/- 0.1% (p = 0.02) and -0.6 +/- 0.9% to 3.4 +/- 1.2% (p = 0.009), respectively. Improvement in epicardial vasomotion was most prominent in segments with baseline endothelial dysfunction evidenced as constriction during stress. Microvascular dilation during adenosine, an endothelium-independent response, was unchanged with losartan.

CONCLUSIONS

Inhibition of the coronary vascular AT1 receptors in patients with atherosclerosis improves epicardial vasomotion during stress, probably by improving endothelial dysfunction. Whether AT1 receptor blockade will provide long-term therapeutic benefits in atherosclerosis needs further investigation.

Association between polymorphism in the chemokine receptor CX3CR1 and coronary vascular endothelial dysfunction and atherosclerosis

Fractalkine, a chemokine expressed by inflamed endothelium, induces leukocyte adhesion and migration via the receptor CX3CR1, and the CX3CR1 polymorphism V249I affects receptor expression and function. Here we show that this polymorphism is an independent risk factor for atherosclerotic coronary artery disease (CAD). Genotyping of the CX3CR1-V249I polymorphism was performed in a cohort of 339 white individuals who underwent cardiac catheterization (n=197 with and n=142 without CAD, respectively). In 203 patients, intracoronary acetylcholine 15 microg/min) and sodium nitroprusside (20 microg/min) were administered to test endothelium-dependent and -independent coronary vascular function, respectively. Change in coronary vascular resistance (DeltaCVR) was measured as an index of microvascular dilation. An association was observed between presence of the CX3CR1 I249 allele and reduced prevalence of CAD, independent of established CAD risk factors (odds ratio=0.54 [95% confidence interval, 0.30 to 0.96], P=0.03). Angiographic severity of CAD was also lower in these subjects (P=0.01). Furthermore, endothelium-dependent vasodilation was greater in these individuals compared with individuals homozygous for the CX3CR1-V249 allele (DeltaCVR during acetylcholine = -46+/-3% versus -36+/-3%, respectively, P=0.02), whereas DeltaCVR with sodium nitroprusside was similar in both groups (-55+/-2% versus -53+/-2%, P=0.45). The association between CX3CR1 genotype and endothelial function was independent of established risk factors and presence of CAD by multivariate analysis (P=0.02). Thus, the CX3CR1 I249 allele is associated with decreased risk of CAD and improved endothelium-dependent vasodilation. This suggests that CX3CR1 may be involved in the pathogenesis of CAD.

Characterization of endothelium-derived hyperpolarizing factor in the human forearm microcirculation

The identity of endothelium-dependent hyperpolarizing factor (EDHF) in the human circulation remains controversial. We investigated whether EDHF contributes to endothelium-dependent vasomotion in the forearm microvasculature by studying the effect of K+ and miconazole, an inhibitor of cytochrome P-450, on the response to bradykinin in healthy human subjects. Study drugs were infused intra-arterially, and forearm blood flow was measured using strain-gauge plethysmography. Infusion of KCl (0.33 mmol/min) into the brachial artery caused baseline vasodilation and inhibited the vasodilator response to bradykinin, but not to sodium nitroprusside. Thus the incremental vasodilation induced by bradykinin was reduced from 14.3 ± 2 to 7.1 ± 2 ml · min−1 · 100 g−1( P < 0.001) after KCl infusion. A similar inhibition of the bradykinin ( P = 0.014), but not the sodium nitroprusside (not significant), response was observed with KCl after the study was repeated during preconstriction with phenylephrine to restore resting blood flow to basal values after KCl. Miconazole (0.125 mg/min) did not inhibit endothelium-dependent or -independent responses to ACh and sodium nitroprusside, respectively. However, after inhibition of cyclooxygenase and nitric oxide synthase with aspirin and N G-monomethyl-l-arginine, the forearm blood flow response to bradykinin ( P = 0.003), but not to sodium nitroprusside (not significant), was significantly suppressed by miconazole. Thus nitric oxide- and prostaglandin-independent, bradykinin-mediated forearm vasodilation is suppressed by high intravascular K+ concentrations, indicating a contribution of EDHF. In the human forearm microvasculature, EDHF appears to be a cytochrome P-450 derivative, possibly an epoxyeicosatrienoic acid.