Male participants (n = 2356), female participants not reporting having undergone menopause (n = 693), participants reporting myocardial infarction, angina, heart failure, arrhythmias (including atrial fibrillation), cardiomyopathy, stroke or peripheral vascular disease (n = 76), and participants using MHT for < 3 years or with missing duration data (n = 246) were excluded from the analysis leaving a study population of 1604.