Atrial fibrillation type and renal dysfunction: new challenges in thromboembolic risk assessment

Clinical prediction scores and early anticoagulation therapy for new-onset atrial fibrillation in critical illness: a post-hoc analysis

Purpose

This study sought to describe the epidemiology of anticoagulation therapy for critically ill patients with new-onset atrial fibrillation (NOAF) according to CHA2DS2-VASc and HAS-BLED scores and to assess the efficacy of early anticoagulation therapy.

Method

Adult patients who developed NOAF during intensive care unit stay were included. We compared the patients who were treated with and without anticoagulation therapy within 48 h from AF onset. The primary outcome was a composite outcome that included mortality and ischemic stroke during the period until hospital discharge.

Results

In total, 308 patients were included in this analysis. Anticoagulants were administered to 95 and 33 patients within 48 h and after 48 h from NOAF onset, respectively. After grouping the patients into four according to their CHA2DS2-VASc and HAS-BLED bleeding scores, we found that the proportion of anticoagulation therapy administered was similar among all groups. After adjustment using a multivariable Cox regression model, we noted that early anticoagulation therapy did not decrease the composite outcome (adjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.47‒1.23). However, in patients without rhythm control drugs, early anticoagulation was significantly associated with better outcomes (adjusted HR 0.46; 95% CI; 0.22‒0.87, P = 0.041).

Conclusions

We found that clinical prediction scores were supposedly not used in the decision to implement anticoagulation therapy and that early anticoagulation therapy did not improve clinical outcomes in critically ill patients with NOAF.

Trial registration UMIN-CTR UMIN000026401. Registered 5 March 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02235-8.

Decreased left atrial appendage emptying velocity as a link between atrial fibrillation type, heart failure and older age and the risk of left atrial thrombus in atrial fibrillation

INTRODUCTION

Decreased left atrial appendage emptying velocity (LAAV) is a known predictor of LAA thrombus in atrial fibrillation (AF). The aim of our study was to identify which of the clinical risk factors for LAA thrombus are associated with decreased LAAV.

METHODS

The study included 1476 consecutive AF patients who underwent transesophageal echocardiography (TEE) before AF direct current cardioversion or ablation in two high-reference cardiology departments. Patients were divided into two groups: 71 (4.8%) patients with LAAV < 20 cm/s and 1405 patients (95%) with LAAV ≥ 20 cm/s.

RESULTS

Compared with patients with LAAV ≥ 20 cm/s, those with decreased LAAV were older, more often had non-paroxysmal AF, were burdened with more concomitant diseases (including hypertension, diabetes, vascular disease, and heart failure [HF]) with higher median CHA₂ DS₂ -VASc score (3 [2-4] vs 2 [1-3], P < .0001), and had lower glomerular filtration rate (GFR). Prevalence of LAA thrombus was higher in patients with decreased LAAV compared with those with LAAV ≥ 20cm/s (20% vs 4.6%, P < .0001). In patients with decreased LAAV, there was no difference in the frequency of LAA thrombus between those treated with VKA and those receiving NOAC, while in patients with LAAV ≥ 20 cm/s a trend was observed towards a benefit with NOAC. In multivariate logistic regression, non-paroxysmal AF, HF and age ≥ 65 years predicted both LAAV < 20 cm/s and LAA thrombus, while GFR < 60 mL/min/1.73 m² predicted only the presence of LAA thrombus.

CONCLUSION

One in five AF patients with decreased LAAV had LAA thrombus, regardless of the type of OAC. Non-paroxysmal AF, HF and age ≥ 65 years might increase LAA thrombus risk via reduced LAAV.

Impact of Glomerular Filtration Rate on the Incidence and Prognosis of New-Onset Atrial Fibrillation in Acute Myocardial Infarction

Background: Atrial fibrillation (AF) is a frequent complication of acute myocardial infarction (AMI) and is associated with a worse prognosis. Patients with chronic kidney disease are more likely to develop AF. Whether the association between AF and glomerular filtration rate (GFR) is also true in AMI has never been investigated. Methods: We prospectively enrolled 2445 AMI patients. New-onset AF was recorded during hospitalization. Estimated GFR was estimated at admission, and patients were grouped according to their GFR (group 1 (n = 1887): GFR >60; group 2 (n = 492): GFR 60–30; group 3 (n = 66): GFR <30 mL/min/1.73 m²). The primary endpoint was AF incidence. In-hospital and long-term (median 5 years) mortality were secondary endpoints. Results: The AF incidence in the population was 10%, and it was 8%, 16%, 24% in groups 1, 2, 3, respectively (p < 0.0001). In the overall population, AF was associated with a higher in-hospital (5% vs. 1%; p < 0.0001) and long-term (34% vs. 13%; p < 0.0001) mortality. In each study group, in-hospital mortality was higher in AF patients (3.5% vs. 0.5%, 6.5% vs. 3.0%, 19% vs. 8%, respectively; p < 0.0001). A similar trend was observed for long-term mortality in three groups (20% vs. 9%, 51% vs. 24%, 81% vs. 50%; p < 0.0001). The higher risk of in-hospital and long-term mortality associated with AF in each group was confirmed after adjustment for major confounders. Conclusions: This study demonstrates that new-onset AF incidence during AMI, as well as the associated in-hospital and long-term mortality, increases in parallel with GFR reduction assessed at admission.

Left Atrial Structural Remodelling in Non-Valvular Atrial Fibrillation: What Have We Learnt from CMR?

Left atrial structural, functional and electrical remodelling are linked to atrial fibrillation (AF) pathophysiology and mirror the phrase “AF begets AF”. A structurally remodelled left atrium (LA) is fibrotic, dysfunctional and enlarged. Fibrosis is the hallmark of LA structural remodelling and is associated with increased risk of stroke, heart failure development and/or progression and poorer catheter ablation outcomes with increased recurrence rates. Moreover, increased atrial fibrosis has been associated with higher rates of stroke even in sinus-rhythm individuals. As such, properly assessing the fibrotic atrial cardiomyopathy in AF patients becomes necessary. In this respect, late-gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard in imaging myocardial fibrosis. LA structural remodelling extension offers both diagnostic and prognostic information and influences therapeutic choices. LGE-CMR scans can be used before the procedure to better select candidates and to aid in choosing the ablation technique, during the procedure (full CMR-guided ablations) and after the ablation (to assess the ablation scar). This review focuses on imaging several LA structural remodelling CMR parameters, including size, shape and fibrosis (both extension and architecture) and their impact on procedure outcomes, recurrence risk, as well as their utility in relation to the index procedure timing.