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Page 8 of 14 Porcari et al. Vessel Plus 2022;6:33 https://dx.doi.org/10.20517/2574-1209.2021.134

[40]
ventricular arrhythmias and bradyarrhythmias (sometimes requiring PM implantation) . The rates of
recurrent arrhythmia can vary from 61% at 30 days to 48%-80% at 1 year following DCCV, depending on
the considered populations and median follow-up time [31,40,41] .

There is a paucity of clinical experience and data in the literature about the safety and efficacy of AF
ablation in CA. In small retrospective cohorts, including both AL and ATTR patients, the procedure was
safe and well tolerated, and it was associated with amelioration of the New York Heart Failure (NYHA)
functional class and quality of life [42,43] . However, the outcome of CA patients undergoing AF ablation
demands further investigation. The recurrence rates of AF following ablation in patients with ATTR-CA are
variable: 25% at 12 months, 40% at 36 months, and 58% at 40 months [31,42,43] . The lower is the ATTR-CA
[44]
stage , the lower is the arrhythmia recurrence rate. In a recent investigation, AF ablation was associated
with lower rates of hospitalization for HF or arrhythmias and improved survival over a mean follow up of
39 months . If some prognostic benefit exists in treating AF in CA, it is likely that rhythm control
[31]
[31]
strategies are substantially more effective when performed earlier in disease course .

When rate control is not tolerated and rhythm control is ineffective, AV node ablation followed by PM
implantation could be an option to relief AF symptoms . Placement of the right ventricular lead in the
[42]
high septal/para-His regions or biventricular pacing should be preferred to prevent deleterious effects of
ventricular dyssynchrony from long-term right ventricular pacing [45,46] .

Arterial thromboembolism and anticoagulant therapy
Post-mortem and in vivo studies using transesophageal echocardiography and cardiac magnetic resonance
demonstrated an increased prevalence of intracardiac thrombosis and arterial thromboembolism in patients
with CA, even in sinus rhythm or in AF under anticoagulation therapy [40,47,48] . According to current
recommendations, patients with non-valvular AF and increased CHA DS -VASc score have a class I
2
2
indication to start anticoagulation preferably with direct oral anticoagulants (DOACs) as first-line therapy
[33]
or with vitamin K antagonists (warfarin) . Although this score is widely used for the prediction of
thromboembolic events in AF , its accuracy has been recently questioned in CA in light of the high
[49]
[50]
prevalence of left atrial appendage (LAA) thrombosis in patients with low CHA DS -VASc score .
2
2
Therefore, Anticoagulation is indicated in most CA patients with AF, regardless of the CHA DS -VASc
2
2
score, and might also be considered in those in sinus rhythm, especially AL-CA, at increased
thromboembolic risk [40,51] revealed by spontaneous echo contrast, transmitral A wave < 20 cm/s, and LAA
velocities < 40 cm/s or lower . A CHA DS -VASc score ≥ 3 has been associated with an almost three-fold
[51]
[52]
2
2
[48]
increased risk of thromboembolic events in CA patients in sinus rhythm , as previously reported in
patients without CA . However, the decision to start empirical anticoagulation and its benefit are largely
[53]
debated.
There are limited data on the optimal anticoagulant strategy in CA. A recent retrospective study comparing
the efficacy of anticoagulant regimens reported no differences in the rate of strokes and transient ischemic
attack in patients with ATTR-CA treated with DOACs and warfarin (2.9 vs. 3.9/100 person/years,
respectively). The decision to initiate anticoagulant therapy should be based on the global assessment of the
risk-benefit ratio in each patient [Table 1]. The selection of the specific anticoagulant regimen cannot be
supported by evidence in CA yet. While waiting results from further prospective studies with larger CA
[33]
cohorts, it is reasonable to consider DOACs as first-line therapy, in line with latest guidelines , and
warfarin in the case of prosthetic mechanical heart valves, moderate-sever mitral stenosis, or recurrent
thrombosis while under DOACs. In the case of prohibitive bleeding risks or contraindications to
anticoagulation (i.e., active major bleeding or severe thrombocytopenia < 50 platelets/μL), LAA closure