Atrial fibrillation: an epidemic in the elderly

Biomarkers for predicting atrial fibrillation: An explorative sub-analysis of the randomised SCREEN-AF trial

BACKGROUND

Atrial fibrillation (AF) is a common treatable risk factor for stroke. Screening for paroxysmal AF in general practice is difficult, but biomarkers might help improve screening strategies.

OBJECTIVES

We investigated six blood biomarkers for predicting paroxysmal AF in general practice.

METHODS

This was a pre-specified sub-study of the SCREEN-AF RCT done in Germany. Between 12/2017-03/2019, we enrolled ambulatory individuals aged 75 years or older with a history of hypertension but without known AF. Participants in the intervention group received active AF screening with a wearable patch, continuous ECG monitoring for 2x2 weeks and usual care in the control group. The primary endpoint was ECG-confirmed AF within six months after randomisation. High-sensitive Troponin I (hsTnI), brain natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (NT-pro BNP), N-terminal pro atrial natriuretic peptide (NT-ANP), mid-regional pro atrial natriuretic peptide (MR-pro ANP) and C-reactive protein (CRP) plasma levels were investigated at randomisation for predicting AF within six months after randomisation.

RESULTS

Blood samples were available for 291 of 301 (96.7%) participants, including 8 with AF (3%). Five biomarkers showed higher median results in AF-patients: BNP 78 vs. 41 ng/L (p = 0.012), NT-pro BNP 273 vs. 186 ng/L (p = 0.029), NT-proANP 4.4 vs. 3.5 nmol/L (p = 0.027), MR-pro ANP 164 vs. 125 pmol/L (p = 0.016) and hsTnI 7.4 vs. 3.9 ng/L (p = 0.012). CRP levels were not different between groups (2.8 vs 1.9 mg/L, p = 0.1706).

CONCLUSION

Natriuretic peptide levels and hsTnI are higher in patients with AF than without and may help select patients for AF screening, but larger trials are needed.

Tachycardia-bradycardia syndrome in a patient with atrial fibrillation: a case report

An 83-year-old woman was scheduled for a second transurethral resection of a bladder tumor. The preoperative electrocardiogram evaluation revealed atrial fibrillation with a slow ventricular response (ventricular rate: 59 /min). After intravenous injection of 1% lidocaine 40 mg and propofol 60 mg, the ventricular rate increased to 113 beats/min and then fell rapidly to 27 beats/min. Blood pressure was 70/40 mmHg. Later an atrial fibrillation rhythm, with a ventricular rate of 100-130 beats/min, was observed together with a sinus pause and sinus rhythm with a ventricular rate of 40-50 beats/min. An external pacemaker was applied and set at 60 mA, 40 counts. After the patient regained consciousness, she presented an alert mental state and had no chest symptoms. She was discharged 2 weeks later without complications after insertion of a permanent pacemaker.

Preferences for oral anticoagulants in atrial fibrillation: a best-best discrete choice experiment

BACKGROUND

Atrial fibrillation (AF) is recognised as a growing clinical and public health problem in many countries, owing to disability and death from stroke associated with the condition, high hospitalisation costs and an increasing prevalence with ageing populations. Under-treatment with oral anticoagulants has been a significant challenge of treatment, historically related to patient concerns over the safety and convenience of warfarin, which until recently was the only oral anticoagulant available.

OBJECTIVES

The aim of this study is to examine: (1) patient preferences for attributes of warfarin and the new oral anticoagulants (dabigatran, rivaroxaban, apixaban) in AF; (2) which attributes are most important; and (3) whether current under-treatment is likely to improve with the new oral anticoagulants.

METHODS

This study was conducted in Melbourne, Australia, with members of the general public with or without AF aged ≥40 years, where those without AF proxy for newly-diagnosed patients. Participants completed a computerised best-best discrete choice experiment (and follow-up interview) as if they had AF with a moderate-to-high risk of stroke. Choice data were modelled using mixed rank-ordered logit. Relative value was explored via estimation of marginal rates of substitution with predicted probability analysis used to simulate potential uptake of oral anticoagulants.

RESULTS

Seventy-six participants were recruited and completed the study. Efficacy (stroke risk) was more important than safety (bleed risk, antidote), which were both considerably more important than convenience factors (blood tests, dose frequency, drug or food interactions). Cost was also important. Predicted use of the new oral anticoagulants (and under-treatment of AF) using simulation, given moderate-to-high risk of stroke, is 25 % (52 %), 54 % (29 %) and 70 % (21 %) assuming a market price of AUD$120/month, AUD$30/month (subsidised price) and AUD$30/month with an antidote, respectively.

CONCLUSIONS

Based on the study sample and the modelled attributes, the overall profiles of the new oral anticoagulants were preferred to warfarin as their cost decreased. Public subsidisation and the development of antidotes (such as vitamin K for warfarin) for the new oral anticoagulants may have a positive effect on the under-treatment of AF.

Atrial fibrillation and microRNAs

Atrial fibrillation (AF) is the most common sustained arrhythmia, especially in the elderly, and has a significant genetic component. Recently, several independent investigators have demonstrated a functional role for small non-coding RNAs (microRNAs) in the pathophysiology of this cardiac arrhythmia. This report represents a systematic and updated appraisal of the main studies that established a mechanistic association between specific microRNAs and AF, focusing both on the regulation of electrical and structural remodeling of cardiac tissue.

Heart dysfunction in patients with acute ischemic stroke or TIA does not predict all-cause mortality at long-term follow-up

BACKGROUND

Despite heart failure being a substantial risk factor for stroke, few studies have evaluated the predictive value of heart dysfunction for all-cause mortality in patients with acute ischemic stroke, in particular in the elderly. The aim of this study was to investigate whether impaired heart function in elderly patients can predict all-cause mortality after acute ischemic stroke or transient ischemic attack (TIA).

METHODS

A prospective long-term follow-up analysis was performed on a hospital cohort consisting of n = 132 patients with mean age 73 ± 9 years, presenting with acute ischemic stroke or transient ischemic attack, without atrial fibrillation. All patients were examined by echocardiography during the hospital stay. Data about all-cause mortality were collected at the end of the follow-up period. The mean follow-up period was 56 ± 22 months.

RESULTS

In this cohort, 58% of patients with acute ischemic stroke or TIA had heart dysfunction. Survival analysis showed that heart dysfunction did not predict all-cause mortality in this cohort. Furthermore, in multivariate regression analysis age (HR 5.401, Cl 1.97-14.78, p < 0.01), smoking (HR 3.181, Cl 1.36-7.47, p < 0.01), myocardial infarction (HR 2.826, Cl 1.17-6.83, p < 0.05) were independent predictors of all-cause mortality.

CONCLUSION

In this population with acute ischemic stroke or TIA and without non-valvular atrial fibrillation, impaired heart function does not seem to be a significant predictor of all-cause mortality at long-term follow-up.

National observatory on the therapeutic management in ambulatory care patients aged 65 and over, with type 2 diabetes, chronic pain or atrial fibrillation

The primary objective of the S.AGES cohort is to describe the real-life therapeutic care of elderly patients. Patients and methods. This is a prospective observational cohort study of 3 700 non-institutionalized patients over the age of 65 years with either type 2 diabetes mellitus (T2DM), chronic pain or atrial fibrillation (AF) recruited by French general practitioners (GPs). Follow-up is planned for 3 years. Baseline characteristics. In the chronic pain sub-cohort, 33% of patients are treated with only grade 1 analgesics, 29% with grade 2 analgesics and 3% with grade 3 analgesics, and 22% have no pain treatment. In the T2DM sub-cohort, 61% of patients have well-controlled diabetes (Hb1c<7%) and 18% are treated with insulin. In the AF sub-cohort, 65% of patients have a CHADS2 score greater than 2, 77% are treated with oral anticoagulants, 17% with platelet inhibitors, 40% with antiarrhythmic drugs and 56% with rate slowing medications. Conclusion. The S.AGES cohort presents a unique opportunity to clarify the real-life therapeutic management of ambulatory elderly subjects and will help to identify the factors associated with the occurrence of major clinical events.

Warfarin slows deterioration of renal function in elderly patients with chronic kidney disease and atrial fibrillation

Background

The purpose of this study was to examine whether long-term use of anticoagulants in elderly patients with atrial fibrillation (AF) and chronic kidney disease (CKD) influences renal function.

Methods

In this retrospective observational study, we reviewed the records of 2023 patients who attended our institution for treatment of CKD between January 2001 and September 2012. Inclusion criteria were having been under review for three months or more, age older than 60 years, permanent AF, a CHADS2 score > 2, and National Kidney Foundation Kidney Disease Outcomes Quality Initiative CKD stage 3–5. Sixty-one patients fulfilled these criteria, and were divided into those receiving antiplatelet anticoagulation (group A) and those receiving warfarin (group B). The results of laboratory investigations and estimated glomerular filtration rate (GFR) were recorded at months 3, 6, 12, and 18 from treatment initiation. We also recorded the occurrence of serious cardiovascular and neurological events, significant bleeding, and survival beyond 12 years.

Results

Of the 61 patients enrolled, 35 were in group A and 26 were in group B. The mean international normalized ratio (INR) was 1.95 ± 1.01 (goal < 3.0). After adjustment for potential confounding variables, we found that patients in group B had a higher estimated GFR (6.06 ± 2.36 mL per minute, P = 0.01). Over a 12-year observation period, group B patients had significantly (P = 0.013) better survival than group A, with an adjusted hazard ratio for mortality of 0.318 (P = 0.022).

Conclusion

Warfarin therapy may delay deterioration in renal function and improve survival of elderly patients with CKD and AF.

Managing atrial fibrillation in the elderly: critical appraisal of dronedarone

Atrial fibrillation is the most commonly seen arrhythmia in the geriatric population and is associated with increased cardiovascular morbidity and mortality. Treatment of the elderly with atrial fibrillation remains challenging for physicians, because this unique subpopulation is characterized by multiple comorbidities requiring chronic use of numerous medications, which can potentially lead to severe drug interactions. Furthermore, age-related changes in the cardiovascular system as well as other physiological changes result in altered drug pharmacokinetics. Dronedarone is a new drug recently approved for the treatment of arrhythmias, such as atrial fibrillation and/or atrial flutter. Dronedarone is a benzofuran amiodarone analog which lacks the iodine moiety and contains a methane sulfonyl group that decreases its lipophilicity. These differences in chemical structure are responsible for making dronedarone less toxic than amiodarone which, in turn, results in fewer side effects. Adverse events for dronedarone include gastrointestinal side effects and rash. No dosage adjustments are required for patients with renal impairment. However, the use of dronedarone is contraindicated in the presence of severe hepatic dysfunction.