The thesis deals with a new solution for the actual scientific and practical task in
the field of knowledge 22 «Healthcare» (the specialty 222 «Medicine»), namely an
improvement of the approaches to the management of patients with non-valvular «late»
persistent atrial fibrillation (AF) (with the duration of its episode 90 and more days), by
the evaluation of baseline clinical and instrumental characteristics, uncovering the
predictors of sinus rhythm (SR) restoration and maintenance, and assessment the
dynamics of structural and functional parameters of myocardial at 6-months follow-up.
The open prospective non-comparative single-center study analyzed the clinical
and instrumental data from 179 patients with non-valvular persistent AF, consecutively
enrolled during the period Feb 2020 – Dec 2022. The enrolled sample included 130
(72,6 %) males and 49 (27,4 %) females aged from 29 to 82 years ([mean ± standard
deviation] 58±11 years on average). Age of AF onset was (median, interquartile range)
54 (47-60) years, the AF history – 5 (3-6) years, and the duration of its last episode –
95 (53-105) days. According to the duration of AF episode, the enrolled sample was
subdivided into two groups: AF episode 8-89 days (90 days) – 64 (55,7 %) patients
(«early» persistent AF), and AF episode 90 days (up to 12 months) – 115 (64,3 %)
patients («late» persistent AF).
Body mass index (BMI) was 30,7 (26,3-34,3) kg/m2
. Fifty-three (29,6 %)
patients were overweight (BMI 25,0-29,9 kg/m2
), and 100 (55,9 %) were obese (BMI
≥30 kg/m2
).
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Essential hypertension was diagnosed in 157 (87,7 %) patients, stable coronary
artery disease – 77 (43,0 %). Seventeen (9,5 %) suffered previously from myocardial
infarction.
Chronic heart failure (HF) of stage B was verified in 59 (33,0 %) patients, аnd
stage C – in 120 (67,0 %). According to NYHA classification, the HF functional
classes distributed as following: ІІ – 120 (67,0 %), ІІІ – 44 (24,6 %), and IV – in 15
(8,4 %).
The risk of thromboembolic events by CHA2DS2-VASc score was 3 (2-4) units.
The severity of AF-related symptoms by modified EHRA classification distributed as
following: class 2b – 119 (66,5 %) patients, class 3 – 45 (25,1 %), and class 4 – 15
(8,4 %).
Three (1,7 %) patients presented with the history of stroke or transient ischemic
attack, 27 (15,1 %) – diabetes mellitus type 2 (DM), 4 (2,2 %) – chronic obstructive
pulmonary disease, and 22 (12,3 %) – autoimmune thyroiditis.
The laboratory tests were performed according to standardized procedures.
Estimated glomerular filtration rate (eGFR) was calculated by CKD-EPI equation
(version 2021). The distribution of eGFR grades among 179 patients was as following:
≥90 ml/min/1,73 m2 – 28 (15,6 %), 60-89 ml/min/1,73 m2 – 115 (64,3 %), and <60
ml/min/1,73 m2 – 36 (20,1 %).
Structural and functional parameters of myocardium were assessed by means of
transthoracic (TTE) and transesophageal echocardiography (TEE) according to
standardized procedures.
Left ventricular (LV) ejection fraction (EF) grades were distributed as following
(N=177): the majority of patients (n=118 [66,7 %]) presented with LV EF ≥50 %
(preserved systolic function), 29 (16,4 %) – 40-49 % (mildly reduced LV EF), and 30
(16,9 %) – <40 % (reduced LV EF).
The signs of pulmonary hypertension (PH) were detected in 149 (84,2 %) of 177
patients with available data: mild – in 127 (85,2 %) patients, and moderate – 22
(14,8 %). Mitral regurgitation was registered in 147 (83,1 %) patients: mild – in 117
(79,6 %) cases, and moderate – 30 (20,4 %). Tricuspid regurgitation (TR) was found
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out in 137 (77,4 %) patients: mild – 114 (83,2 %), and moderate – in 23 (16,8 %)
cases.
The function of left atrial appendage (LAA) was evaluated by the peak blood
flow velocity (LAAV) (by TEE), being 38 (31-51) cm/s on average among the enrolled
patients, and ≤40 cm/s in 56,4 % (n=101) cases. Left atrial spontaneous echo contrast
(LASEC) was visualized in 80 (44,7 %) patients, including its I-II degree – in 52
(65 %) cases, and ІІІ-IV degree – in 28 (35 %).
The diagnostic invasive coronary angiography was performed in 45,3 % (n=81)
patients. Forty-seven (58 %) patients did not demonstrate the significant stenotic
lesions of subepicardial coronary arteries; single-vessel disease was detected in 17
(21 %) patients, 2-vessel – in 12 (15 %), and 3-vessel – in 5 (6 %) cases. Myocardial
revascularization (either by percutaneous coronary intervention [PCI] or coronary
artery bypass grafting) was previously performed in 28 (15,6 %) patients.
Aiming to reveal the predictors of SR restoration, we analysed the data from 115
patients with long-term episodes (≥90 days) of persistent AF, undergoing elective
direct-current cardioversion (DCCV). The anticoagulants and amiodarone were
prescribed to all the patients for, at least, 3 weeks before cardioversion.
