Table 1.
Patient characteristics
| Variables | AF group n = 230 |
Amyloid group n = 12 |
Excluded n = 107 |
|---|---|---|---|
| Clinical parameters | |||
| Age (range), years | 67 ± 12 (21–91) | 77 ± 7 (62–89) | 68 ± 11 (35–97) |
| Female sex, n (%) | 69 (30) | 4 (33) | 40 (37) |
| BSA, m2 | 1.72 ± 0.20 | 1.61 ± 0.19 | 1.69 ± 0.18 |
| Underlying heart disease, n (%) | 16 (7) | — | 10 (9) |
| Ischaemic cardiomyopathy | 3 (1) | — | 1 (1) |
| Dilated cardiomyopathy | 5 (2) | — | 5 (5) |
| Hypertrophic cardiomyopathy | 8 (3) | — | 4 (4) |
| CHA2DS2-VASc, median (IQR) | 2 (1–3) | 3 (3–5) | 2 (1–3) |
| History of heart failure, n (%) | 56 (24) | 9 (75) | 29 (27) |
| HFrEF | 22 (10) | 0 (0) | 13 (12) |
| HFmrEF | 9 (4) | 2 (17) | 3 (3) |
| HFpEF | 25 (11) | 7 (58) | 13 (12) |
| Hypertension, n (%) | 129 (56) | 8 (67) | 55 (51) |
| Diabetes mellitus, n (%) | 42 (18) | 3 (25) | 18 (17) |
| History of stroke, n (%) | 19 (8) | 1 (8) | 14 (13) |
| eGFR, mL/min/1.73 m2 | 63 ± 18 | 51 ± 13 | 63 ± 16 |
| AF type, n (%) | |||
| PAF | 86 (37) | 5 (42) | 45 (42) |
| PeAF | 78 (34) | 6 (50) | 44 (41) |
| LS-PeAF | 66 (29) | 1 (8) | 18 (17) |
| Medication at baseline, n (%) | |||
| ACEi or ARB | 86 (37) | 7 (58) | 42 (39) |
| MRA | 15 (7) | 0 (0) | 5 (5) |
| Diuretics (other than MRA) | 30 (21) | 3 (25) | 17 (16) |
| Class I antiarrhythmic drugs | 34 (15) | 3 (25) | 20 (19) |
| Beta blockers | 119 (52) | 6 (50) | 53 (50) |
| Amiodarone | 19 (8) | 4 (33) | 11 (10) |
| Bepridil | 15 (7) | 1 (8) | 9 (8) |
| LA volume/BSA, mL/m2 | 96 ± 27 | 93 ± 12 | 99 ± 30 |
| LA diameter, mm | 41 ± 6 | 40 ± 5 | 42 ± 7 |
| LV ejection fraction, % | 62 ± 12 | 59 ± 15 | 63 ± 13 |
| E/e’ | 9.4 ± 4.1 | 14.2 ± 6.4 | 9.9 ± 4.6 |
| Voltage parameters | |||
| Vbiopsy, mV | 8.5 ± 3.0 | 5.3 ± 3.1 | 7.7 ± 3.0 |
| VGLA, mV | 6.0 ± 2.2 | 3.5 ± 2.2 | 5.3 ± 2.1 |
| LVA, n (%) | 31 (13) | 6 (50) | 16 (15) |
| Histological parameters | |||
| Tissue samples, n, median (IQR) | 4 (3–5) | 5 (3–5) | 3 (2–4) |
| Long diameter, mm, median (IQR) | 1.5 (1.2–1.9) | 1.4 (1.1–1.8) | 1.4 (1.1–1.7) |
| Short diameter, mm, median (IQR) | 1.0 (0.7–1.2) | 0.9 (0.7–1.2) | 0.7 (0.5–0.9) |
| Myocardium (+)a, n, median (IQR) | 2 (1–3) | — | — |
| Amyloid (+), n, median (IQR) | — | 3 (2–4) | — |
| Analysis area, µm2 | 762 325 ± 583 116 | — | — |
| %Fibrosis, % | 7.0 ± 3.8 | — | — |
| %Intercellular space, % | 20.8 ± 8.4 | — | — |
| %Myofibrillar loss, % | 20.9 ± 10.4 | — | — |
| %Adipocyte, %, median (IQR) | 0.4 (0.2–0.7) | — | — |
| Myocyte size, µm | 16.8 ± 3.9 | — | — |
| Nuclear density, /mm2 | 384 ± 141 | — | — |
| Myocyte disarray, median (IQR) | 2 (1–2) | — | — |
ACEi, angiotensin-converting enzyme inhibitor; AF, atrial fibrillation; ARB, angiotensin II receptor blocker; BSA, body surface area; eGFR, estimated glomerular filtration rate; HFmrEF, heart failure with mid-range ejection fraction; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; IQR, interquartile range; LA, left atrium; LS-PeAF, long-standing persistent AF; LV, left ventricle; LVA, presence of low-voltage area defined as <0.5 mV and ≥3.0 cm2; MRA, mineralocorticoid receptor antagonist; PAF, paroxysmal AF; PeAF, persistent AF; Vbiopsy, voltage at the biopsy site; VGLA, global left atrial voltage; %Adipocyte, extent of adipocyte; %Fibrosis, extent of fibrosis; %Intercellular space, extent of intercellular space; %Myofibrillar loss, severity of myofibrillar loss.
Number of tissue samples containing cardiomyocytes; LA volume was measured by computed tomography.