Myocardial infarction risk and hormone replacement: differences between products.

Area of Science:

• Cardiovascular Health
• Endocrinology
• Pharmacology

Background:

• Hormone replacement therapy (HRT) is widely used for menopausal symptoms.
• The association between HRT and cardiovascular events, particularly myocardial infarction (MI), remains a significant area of research.
• Understanding the comparative risks across different HRT regimens is crucial for clinical practice.

Purpose of the Study:

• To determine the risk of myocardial infarction (MI) in hormone replacement therapy (HRT) users versus non-users.
• To compare the risk of MI among various HRT regimens, modes of administration, and durations of use.

Main Methods:

• A population-based cohort and case-control study design was employed.
• Data were sourced from the UK General Practice Research Database.
• Confounding factors were adjusted for, and analyses examined differences in HRT regimen, administration, and duration.

Main Results:

• Both current and past HRT use were associated with a reduced risk of MI compared to no prior use.
• Myocardial infarctions were less likely to be fatal in HRT users (OR(adj) 0.58; 95% CI 0.45-0.75).
• No significant differences in MI risk were observed between current and past use, oral versus transdermal HRT, or different HRT regimens.

Conclusions:

• Findings support the hypothesis that postmenopausal HRT use is associated with a decreased risk of acute myocardial infarction (AMI).
• A protective effect of HRT is suggested by the difference in case fatality between users and non-users.
• This study did not identify significant differences in MI risk among various HRT regimens.