Thromboembolism after coronavirus disease 2019 vaccination in atrial fibrillation/flutter: a self-controlled case series study.

BACKGROUND AND AIMS: Concerns about the safety of coronavirus disease 2019 (COVID-19) vaccines in patients with atrial fibrillation/flutter (AF/AFL) have arisen due to reports of thrombo-embolic events following COVID-19 vaccination in the general population. This study aimed to evaluate the risk of thrombo-embolic events after COVID-19 vaccination in patients with AF/AFL. METHODS: This was a modified self-controlled case-series study using a comprehensive nationwide-linked database provided by the National Health Insurance Service in South Korea to calculate incidence rate ratios (IRRs) of thrombo-embolic events. The study population included individuals aged ≥12 years who were either vaccinated (e.g. one or two doses) or unvaccinated during the period from February to December 2021. The primary outcome was a composite of thrombo-embolic events, including ischaemic stroke, transient ischaemic attack, and systemic thromboembolism. The risk period was defined as 0-21 days following COVID-19 vaccination. RESULTS: The final analysis included 124 127 individuals with AF/AFL. The IRR of thrombo-embolic events within 21 days after COVID-19 vaccination, compared with that during the unexposed control period, was 0.93 [95% confidence interval (CI) 0.77-1.12]. No significant risk variations were noted by sex, age, or vaccine type. However, patients without anticoagulant therapy had an IRR of 1.88 (95% CI 1.39-2.54) following vaccination. CONCLUSIONS: In patients with AF/AFL, COVID-19 vaccination was generally not associated with an increased risk of thrombo-embolic events. However, careful individual risk assessment is required when advising vaccination for those not on oral anticoagulant, as these patients exhibited an increased risk of thrombo-embolic events post-vaccination.

Management of atrial arrhythmias identified by cardiac devices.

Implantable cardiac devices have shown that atrial fibrillation (AF) is more frequent than previously assumed, with subclinical, asymptomatic, self-limiting manifestations called atrial high-rate events (AHREs) or subclinical AF. The clinical significance and correct therapeutic management of these episodes of subclinical AF is less well defined than in the case of clinically manifest AF. Two important randomized studies on the topic have recently been published, NOAH-AFNET 6 and ARTESIA, which, however, have not definitively clarified the topic. In patients with AHRE or subclinical AF, the average thrombo-embolic risk is lower than that in patients with clinically manifest AF and is ∼1%. For this reason, in these patients, the possibility that the benefit of anticoagulant therapy is overshadowed by the risk of bleeding is very high. Therefore, while waiting for new tools that allow a better stratification of low-risk patients, we must rely on individual clinical evaluation and overcome the qualitative dichotomy (AHRE yes vs. AHRE no), preferring instead an approach that is as quantitative as possible and takes into account the number of episodes, their duration, and the patient's CHADSVASC score, before deciding, in each individual case, whether or not to use anticoagulant therapy.

The influence of atrial high-rate episodes on stroke and cardiovascular death: an update.

Atrial high-rate episodes (AHRE) are atrial tachyarrhythmias detected by continuous rhythm monitoring by pacemakers, defibrillators, or implantable cardiac monitors. Atrial high-rate episodes occur in 10-30% of elderly patients without atrial fibrillation. However, it remains unclear whether the presence of these arrhythmias has therapeutic consequences. The presence of AHRE increases the risk of stroke compared with patients without AHRE. Oral anticoagulation would have the potential to reduce the risk of stroke in patients with AHRE but is also associated with a rate of major bleeding of ∼2%/year. The stroke rate in patients with AHRE appears to be lower than the stroke rate in patients with atrial fibrillation. Wearables like smart-watches will increase the absolute number of patients in whom atrial arrhythmias are detected. It remains unclear whether anticoagulation is effective and, equally important, safe in patients with AHRE. Two randomized clinical trials, NOAH-AFNET6 and ARTESiA, are expected to report soon. They will provide much-needed information on the efficacy and safety of oral anticoagulation in patients with AHRE.

How much does the presentation pattern of atrial fibrillation affect thrombo-embolic risk and mortality?

Atrial fibrillation (AF) is associated with a substantial increase in mortality and morbidity. Systemic thrombo-embolism is the most serious complication associated with this arrhythmia. The use of anticoagulant drugs is the cornerstone of therapy for the prophylaxis of stroke and peripheral ischaemia in these patients. The current guidelines recommend the use of anticoagulant drugs based on the thrombo-embolic risk profile of each individual patient calculated by SCORE based on the presence or absence of clinical risk factors and regardless of the presentation pattern of AF. A review of literature data investigating the effect of AF presentation pattern on thrombo-embolic risk and mortality showed an increased risk of both thrombo-embolic events and death in patients with non-paroxysmal AF compared to patients with paroxysmal AF. Most of these studies, however, consist of post-hoc analyses of large trials or observational studies and meta-analyses derived from these, resulting in an important limitation in the interpretation of data derived from such studies. At the same time, these data suggest the need for both new therapies to prevent AF progression and for further studies to explore the integration of AF presentation pattern into models of thrombo-embolic risk.

What do we do about atrial high rate episodes?

Atrial high rate episodes (AHREs) are defined as asymptomatic atrial tachyarrhythmias detected by cardiac implantable electronic devices with atrial sensing, providing automated continuous monitoring and tracings storage, occurring in subjects with no previous clinical atrial fibrillation (AF) and with no AF detected at conventional electrocardiogram recordings. AHREs are associated with an increased thrombo-embolic risk, which is not negligible, although lower than that of clinical AF. The thrombo-embolic risk increases with increasing burden of AHREs, and moreover, AHREs burden shows a dynamic pattern, with tendency to progression along with time, with potential transition to clinical AF. The clinical management of AHREs, in particular with regard to prophylactic treatment with oral anticoagulants (OACs), remains uncertain and heterogeneous. At present, in patients with confirmed AHREs, as a result of device tracing analysis, an integrated, individual and clinically-guided assessment should be applied, taking into account the patients' risk of stroke (to be reassessed regularly) and the AHREs burden. The use of OACs, preferentially non-vitamin K antagonists OACs, may be justified in selected patients, such as those with longer AHREs durations (in the range of several hours or ≥24 h), with no doubts on AF diagnosis after device tracing analysis and with an estimated high/very high individual risk of stroke, accounting for the anticipated net clinical benefit, and informed patient's preferences. Two randomized clinical trials on this topic are currently ongoing and are likely to better define the role of anticoagulant therapy in patients with AHREs.

Complex percutaneous transcatheter closure of incomplete surgical ligation of the left atrial appendage: a case report.

Background: Incomplete surgical left atrial appendage (LAA) closure, in the form of incompletely surgically ligated LAA (ISLL), increases thrombo-embolic risk in patients with atrial fibrillation (AF). Although its management is not standardized, the percutaneous closure of ISLL could be an alternative in patients with contraindication for anticoagulants. We present the case of a percutaneous transcatheter LAA device implantation in a patient with AF and ISLL, complicated by severe anaemia. Case summary: A 83-year-old woman, with permanent AF and a history of previous surgical LAA ligation, was referred to our hospital for fatigue and worsening dyspnoea. Laboratory tests showed severe microcytic anaemia, with a haemoglobin level of 4.9 g/dL (normal reference: 13.8-18.0 g/dL). Oesophagogastroduodenoscopy and colonoscopy excluded signs of either recent or ongoing haemorrhage. After achieving clinical improvement by haemotransfusions, we performed a transoesophageal echocardiography that showed an ISLL with a narrow neck of 5 mm. Since the patient had high thrombo-embolic and haemorrhagic risk (CHA2DS2-VASc risk score of 4 and a HAS-BLED score of 4), we decided to discontinue anticoagulant therapy and perform elective percutaneous transcatheter LAA occlusion (LAAO) with an Amplatzer Amulet device. Patient was discharged in good clinical status. After three months, the stability of haemoglobin level and the absence of device thrombosis allowed the discontinuation of antithrombotic therapy. Discussion: We described the first experience of percutaneous ISLL closure with Amulet device (Abbott Vascular, Santa Clara, CA, USA), a commercially available device for LAAO. The procedure was feasible and safe, without long-term complications.

NOAC in "real world" patients with atrial fibrillation in Italy: results from the ISPAF-2 (Indagine Sicoa Paziente Con Fibrillazione Atriale) survey study.

In the past few years, new oral anticoagulants (NOACs) targeting directly a single activated clotting factor, have been developed for the treatment of non-valvular atrial fibrillation (AF), which are currently recommended as first-line therapy in AF. The aim of this study is to provide an overall picture on the extent to which oral anticoagulation (OAC) with NOACs correspond to actually prescribed OAC therapy in an unselected, real world, population of consecutive patients with AF in Italy. Compliance with the therapy and quality of life were also assessed. A 50 cardiology unit network located in different geographic areas of Italy enrolled a total of 1742 consecutive outpatients with AF (54.6% males, 45.4% females, mean age 72.5 years). NOACs were prescribed in 56.1% patients and VKA in 43.9% (P < 0.0001). NOACs were significantly more prescribed than VKA in patients with high thrombo-embolic risk score (i.e., CHA2DS2-VASc > 2) (78.2 vs 67.3%, P < 0.0001), but also patients at low risk (i.e., CHA2DS2-VASc < 1 and HAS-BLED < 3) were still under OAC therapy with either NOACs (27%) or VKA (73%). Adherence to therapy (Morisky test) was greater in patients taking NOACs as was the quality of life. The ISPAF-2 study shows that in an Italian population of real-world patients with AF the prescription of OAC according to current guidelines and stroke-risk scoring system is rather high although it still needs to be improved. Contrary to recommendations, in a high proportion of low-risk patients, anticoagulation therapy, with either NOACs and VKA is still prescribed, and this exposes patients to unjustified risks.

Anticoagulation in "real world" patients with atrial fibrillation in Italy: results from the ISPAF (Indagine Sicoa Paziente Con Fibrillazione Atriale) survey study.

BACKGROUND: Atrial fibrillation (AF) is associated with a high risk of stroke and other thrombo-embolic events and their prevention relies on antithrombotic therapy, at present mainly with vitamin K antagonists (VKA). The aim of this study was to provide an overall picture on the extent to which current recommendations on oral anticoagulation (OAC) therapy with VKA in AF correspond to actually prescribed OAC in an unselected, real world, population of consecutive patients with AF in Italy. Secondary objective was to assess the rate of "optimal" anticoagulation. METHODS: Sixty-three cardiology units located in different geographic areas of Italy enrolled a total of 2046 outpatients with nonvalvular AF (54% males and 46% females, age 73.3±10.2 years). RESULTS: OAC with VKAs was prescribed in 1394 (68%) of patients and was progressively more frequent on going from paroxysmal (46%) to persistent (71%) and permanent AF (78%)(P<0.001). A high prescription rate (88%) occurred in patients with CHA2DS2-VASc >2. In patients with CHA2DS2-VASc=0 and HAS-BLED<3, still 59% were on OAC, whereas in 33% of patients with CHA2DS2-VASc ≥2 and HAS-BLED<3, OAC therapy was not prescribed. In patients with CHA2DS2-VASc ≥2 and HAS-BLED>3, the preference was towards OAC prescription. 66% of patients were at target for INR. CONCLUSIONS: The ISPAF study shows that in an Italian population of real world patients with AF adherence to current guidelines on OAC therapy based on stroke-risk scoring system is rather high, although rate of prescription should be increased. However, contrary to recommendations, in a high proportion of low-risk patients OAC therapy is still prescribed, and this might expose patients to unjustified risks.