Table 15.
Risk of AF in thyroid dysfunction
| Study | Design | Subjects | FU | Thyroid function | AF,% | Risk (95%CI) |
|---|---|---|---|---|---|---|
| Selmer et al249 | Cohort | 586460 | 5.5 yrs | Euthyroid | 2.9 | Reference |
| Overt Hyperthyroid | 4.6 | IRR 1.42 (1.22–1.63) | ||||
| Subclinical Hyperthyroid | – | IRR 1.31 (1.19–1.44) | ||||
| Overt Hypothyroid | 2.5 | IRR 0.67 (0.5–0.9) | ||||
| Subclinical Hypothyroid TSH levels | – | IRR 0.87 (0.7–0.97) | ||||
| Reduced TSH | – | IRR 1.16 (0.99–1.36) | ||||
| Suppressed TSH | – | IRR 1.41 (1.35–1.89) | ||||
| High-normal Euthyroid (TSH levels) | – | IRR 1.12 (1.03–1.21) | ||||
| Cappola et al.251 | Cohort | 3233 | 13 yrs | Euthyroid | 5.2 | Reference |
| Cardiovascular Health study | >65 yrs | Subclinical Hyperthyroid | 8.5 | HR 1.98 (1.29–3.03)a | ||
| Overt Hypothyroid | 4.8 | HR 0.96 (0.52–1.79)a | ||||
| Subclinical Hypothyroid | 3.9 | HR 1.13 (0.94–1.36)a | ||||
| Frost et al.250 | Cohort | 40628 | 30 days | Overt Hyperthyoid | 8.3 | – |
| Auer et al.253 | Retrospective | 23 638 elderly | – | Euthyroid | 2.3 | – |
| Overt Hyperthyroid | 13.8 | – | ||||
| Subclinical Hyperthyroid | 12.7 | RR 5.2 (2.1–8.7) | ||||
| Gammage et al254 | Cohort | 5860 | – | Euthyroid | 4.7 | Reference |
| >65 yrs | Subclinical Hyperthyroid | 9.5 | OR 1.87(1.01—3.57)b | |||
| Subclinical Hypothyroid | 4.2 | – | ||||
| Serum free T4 | – | OR 1.09 (1.03–1.15) | ||||
| Sawin et al.255 | Cohort | 2007 | 10 yrs | Euthyroid | 8.4 | |
| Framingham Heart study | Reduced TSH 0.1–0.4 μU/L | 12.2 | RR 1.6 (1.0–2.5) | |||
| Suppressed TSH <0.1 μU/L | 21.3 | RR 3.8 (1.7–8.3) | ||||
| Colett et al256 | Meta-analysis | 52674 | 8.8 yrs | Subclinical Hyperthyroid | – | HR 1.68 (1.16–2.43) |
| Thyroid studies collaborators | Reduced TSH | – | HR 1.63 (1.1 –2.4) | |||
| Suppressed TSH | – | HR 2.54 (1.08–5.99) | ||||
| Heeringa et al257 | Registry | 1426 | 8 yrs | High-normal Euthyroid (TSH levels) TSH - 0.4–1.04 mU/L |
7.3 | HR 1.94 (1.13–3.34)c |
| Kim et al252 | Cohort | 5055 | 10 yrs | TSH 0.45–4.5 μU/L | 5.4 | Reference |
| Framingham Heart study | TSH 4.5–10.0 μU/L | 7.0 | HR 1.23 (0.77–1.97) | |||
| TSH 10.0–19.9 μU/L | 4.0 | HR 0.57 (0.21–1.54) |
Definitions of thyroid dysfunction.249
Euthyroidism: TSH 0.2–5.0 mlU/L free thyroxine 9–22 pmol/L total thyroxine 60–140 mmol/L
Overt hypothyroidism: TSH >5.0 mlU/L free thyroxine <9 pmol/L; total thyroxine <60 mmol/L
Subclinical hypothyroidism: TSH >5.0 mlU/L; free thyroxine 9–22 pmol/L total thyroxine 60–140 mmol/L
Overt hyperthyroidism: TSH <0.2 mlU/L; free thyroxine >22 pmol/L; total thyroxine >140 mmol/L.
Subclinical hyperthyroidism: TSH <0.2 mlU/L; free thyroxine 9–22 pmol/L total thyroxine 60–140 mmol/L
TSH level dependent thyroid dysfunction.249
Euthyroidism: TSH 0.4–5.0 MiU/L; free thyroxine 9–22 pmol/L total thyroxine 60–140 mmol/L
High normal euthyroidism: TSH 0.2–0.4 mlU/L; free thyroxine 9–22 pmol/L total thyroxine 60–140 mmol/L
Subclinical hyperthyroidism (reduced TSH): TSH 0.1 –0.2 mlU/L; free thyroxine 9–22 pmol/L; total thyroxine 60–140 mmol/L.
Subclinical hyperthyroidism (suppressed TSH): TSH <0.1 mlU/L; free thyroxine 9–22 pmol/L total thyroxine 60–140 mmol/L
AF, atrial fibrillation; BMI, body mass index; Cl, confidence interval; CVD, cardiovascular disease; d, days; DM, diabetes mellitus; HF, heart failure; HR, hazard ratio; HT, hypertension; IRR, incidence rate ratio; LVF, left ventricular function; Ml, myocardial infarction; OR, odds ratio; pts, patients; RR, relative risk; SBP, systolic blood pressure; TSH, thyroid stimulating hormone; VHD, valvular heart disease; yrs, years.
Adjusted for age, sex, CVD, thyroid medication use, atrial size, SBP, fasting glucose. VHD, β-blockers and diuretics use.
Adjusted for male, age >70, DM, HF, HT.
Adjusted for age, sex, smoking, BMI, SBP, HT, HF, Ml, LVF, DM.