WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: General use of hormone replacement therapy (HRT) dropped drastically after 2002 when pivotal randomized trials showed increased risk of coronary artery disease and other complications with HRT. HRT is not recommended for primary or secondary prevention of coronary heart disease and guidelines recommend discontinuation of HRT after myocardial infarction (MI). It is unknown whether women actually discontinue HRT after MI.