Mette Nygaard Andersen1, Anne-Marie Schjerning Olsen1, Jesper Clausager Madsen1, Søren Lund Kristensen1, Jens Faber1, Christian Torp-Pedersen1, Gunnar H Gislason1, Christian Selmer1. 1. Department of Cardiology (M.N.A., A.-M.S.O., S.L.K., G.H.G.), Gentofte University Hospital, 2900 Hellerup, Denmark; Elective Laboratory of the Capital Region (J.C.M.), 1112 Copenhagen, Denmark; Department of Endocrinology (J.F.), Herlev University Hospital, 2730 Herlev, Denmark; Faculty of Health Sciences (J.F., G.H.G.), University of Copenhagen, 1165 Copenhagen, Denmark; Department of Health Science and Technology (C.T.-P.), University of Aalborg, 9100 Aalborg, Denmark; The Danish Heart Foundation (G.H.G.), 1120 Copenhagen, Denmark; The National Institute of Public Health (G.H.G.), University of Southern Denmark, 1399 Copenhagen, Denmark; and Department of Endocrinology (C.S.), Amager and Hvidovre University Hospital, 2650 Copenhagen, Denmark.
Abstract
CONTEXT: Subclinical hypothyroidism is a common condition that may lead to impaired cardiac function. OBJECTIVE: This study sought to examine the effects of levothyroxine treatment in patients with subclinical hypothyroidism and heart disease. DESIGN: This was a register-based historical cohort study. SETTING AND PARTICIPANTS: The study was composed of Danish primary care patients and hospital outpatients age 18 years and older with established heart disease who were diagnosed with subclinical hypothyroidism in 1997-2011. Patients were stratified according to whether they claimed a subsequent prescription of levothyroxine. Event rates and incidence rate ratios (IRR) were calculated by use of time-dependent multivariable Poisson regression models. MAIN OUTCOME MEASURES: Measures included all-cause mortality and major adverse cardiac events (MACEs), defined as cardiovascular death, fatal or nonfatal myocardial infaction and stroke, and all-cause hospital admissions. RESULTS: Of 61 611 patients with a diagnosis of cardiac disease having their first time thyroid function testing, 1192 patients with subclinical hypothyroidism (mean age 73.6 [SD ± 13.3] y, 63.8% female) were included, of whom 136 (11.4%) were treated with levothyroxine. During a median follow-up time of 5.6 y (interquartile range, 6.5 y), 694 (58.2%) patients died. Patients treated with levothyroxine displayed no significantly increased risk of all-cause mortality (adjusted IRR, 1.17; 95% confidence interval [CI], 0.90-1.52), MACE (adjusted IRR, 1.08; 95% CI, 0.80-1.45), or hospital admission (adjusted IRR, 0.94; 95% CI, 0.71-1.24), when compared with patients not treated with levothyroxine. CONCLUSION: Levothyroxine treatment in patients with subclinical hypothyroidism and heart disease was not associated with a significant benefit nor risk of all-cause mortality, MACE, or hospital admission in this large real-world cohort study.
CONTEXT: Subclinical hypothyroidism is a common condition that may lead to impaired cardiac function. OBJECTIVE: This study sought to examine the effects of levothyroxine treatment in patients with subclinical hypothyroidism and heart disease. DESIGN: This was a register-based historical cohort study. SETTING AND PARTICIPANTS: The study was composed of Danish primary care patients and hospital outpatients age 18 years and older with established heart disease who were diagnosed with subclinical hypothyroidism in 1997-2011. Patients were stratified according to whether they claimed a subsequent prescription of levothyroxine. Event rates and incidence rate ratios (IRR) were calculated by use of time-dependent multivariable Poisson regression models. MAIN OUTCOME MEASURES: Measures included all-cause mortality and major adverse cardiac events (MACEs), defined as cardiovascular death, fatal or nonfatal myocardial infaction and stroke, and all-cause hospital admissions. RESULTS: Of 61 611 patients with a diagnosis of cardiac disease having their first time thyroid function testing, 1192 patients with subclinical hypothyroidism (mean age 73.6 [SD ± 13.3] y, 63.8% female) were included, of whom 136 (11.4%) were treated with levothyroxine. During a median follow-up time of 5.6 y (interquartile range, 6.5 y), 694 (58.2%) patients died. Patients treated with levothyroxine displayed no significantly increased risk of all-cause mortality (adjusted IRR, 1.17; 95% confidence interval [CI], 0.90-1.52), MACE (adjusted IRR, 1.08; 95% CI, 0.80-1.45), or hospital admission (adjusted IRR, 0.94; 95% CI, 0.71-1.24), when compared with patients not treated with levothyroxine. CONCLUSION:Levothyroxine treatment in patients with subclinical hypothyroidism and heart disease was not associated with a significant benefit nor risk of all-cause mortality, MACE, or hospital admission in this large real-world cohort study.
Authors: Richard Birtwhistle; Kate Morissette; James A Dickinson; Donna L Reynolds; Marc T Avey; Francesca Reyes Domingo; Rachel Rodin; Brett D Thombs Journal: CMAJ Date: 2019-11-18 Impact factor: 8.262
Authors: Nydia Burgos; Freddy J K Toloza; Naykky M Singh Ospina; Juan P Brito; Ramzi G Salloum; Leslie C Hassett; Spyridoula Maraka Journal: Thyroid Date: 2020-12-29 Impact factor: 6.568