Interdisciplinary Department of Internal Medicine, University of Bari "A. Moro", Bari, Italy.
Department of Translational Medical Sciences, Federico II University, Naples, Italy.
Front Endocrinol (Lausanne). 2022 Nov 15;13:1013641. doi: 10.3389/fendo.2022.1013641. eCollection 2022.
Chronic heart failure (CHF) affects the health care system with high social and economic costs due to recurrent hospital admissions or frequent ambulatory reassessments. Subclinical hypothyroidism (SCH) is commonly observed in patients with CHF and negatively affects myocardial function and remodeling and, ultimately, increases the risk of hospitalizations and all-cause and cardiovascular (CV) mortality. The role of levothyroxine replacement on relevant CV outcomes in patients with SCH and CHF is unclear.
To assess the effect of levothyroxine (compared to placebo or no treatment) on the incidence of all-cause and CV mortality, major adverse CV events, and heart failure in patients with SCH and CHF.
PubMed/MEDLINE, Cochrane Library, and ClinicalTrial.gov were searched for randomized clinical trials, non-randomized observational, multicentric, and comparative studies. No language restrictions were included. After duplicate removal, articles were screened and extracted for the synthesis according to a hierarchical strategy that included title, abstract, and full-text appraisal. The risk of bias was assessed by RoB2 and ROBIN-I tools. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was applied to rate the quality of evidence and grade the strength of recommendations.
Two trials were included in the systematic review with considerable indirectness and inaccuracy that down-graded the level of evidence.
No evidence supports the use of levothyroxine for treating SCH in CHF due to the lack of reliable and well-designed clinical trials.
CV outcome and dose-response trials are needed to understand better the role of levothyroxine replacement treatment for a safer prescription in this clinical setting.
慢性心力衰竭（CHF）由于反复住院或频繁门诊评估，给医疗保健系统带来了高社会和经济成本。亚临床甲状腺功能减退症（SCH）在 CHF 患者中很常见，会对心肌功能和重塑产生负面影响，并最终增加住院和全因及心血管（CV）死亡率的风险。SCH 和 CHF 患者中左甲状腺素替代治疗对相关 CV 结局的作用尚不清楚。
评估左甲状腺素（与安慰剂或不治疗相比）对 SCH 和 CHF 患者全因和 CV 死亡率、主要不良 CV 事件和心力衰竭发生率的影响。
检索了 PubMed/MEDLINE、Cochrane 图书馆和 ClinicalTrials.gov 中的随机临床试验、非随机观察性、多中心和比较研究。未包括语言限制。重复去除后，根据包括标题、摘要和全文评估的分层策略筛选和提取文章进行综合。使用 RoB2 和 ROBIN-I 工具评估偏倚风险。应用推荐评估、制定和评估（GRADE）方法学对证据质量进行分级，并对建议的强度进行分级。
系统评价纳入了两项试验，但存在较大的间接性和不准确性，降低了证据水平。
由于缺乏可靠和精心设计的临床试验，没有证据支持使用左甲状腺素治疗 CHF 中的 SCH。
需要进行 CV 结局和剂量反应试验，以更好地了解左甲状腺素替代治疗在这种临床情况下的作用，以实现更安全的处方。
