Rationale and design of the PREGnancy, HEART Health and Cardiovascular Disease (PREG-HEART) Cohort Study

Abstract Introduction: Cardiovascular disease is a leading cause of maternal and neonatal morbidity and mortality in the UK. Its prevalence in pregnancy continues to rise, driven by both improved survival of women with congenital and inherited heart disease into reproductive age and an increasing burden of acquired cardiovascular risk factors. However, its natural history and optimal management remain poorly defined. Current research is limited by small sample sizes, drawn from highly selected patient cohorts from individual units. The aim of the PREGnancy, HEART Health, and Cardiovascular Disease (PREG-HEART) study is to develop a patient driven, clinically relevant, digital platform to understand the epidemiology of cardiovascular disease in pregnancy and support clinical trials of management strategies. This paper provides the protocol for PREG-HEART, which will start with a 6-month pilot study. Methods and analysis: PREG-HEART will utilise an online, direct-to-patient platform to enrol patients with cardiovascular disease in pregnancy alongside healthy pregnant controls. Enrolled women will be invited to provide self-reported demographic and clinical data and consent to linkage with national health records for long-term follow up. We will also seek consent for storage and analysis of leftover clinical biosamples and to re-contact participants, enabling recruitment into sub-studies and clinical trials. Planned analysis for the pilot study at 6 months will assess feasibility, including recruitment rates, case-mix of cardiovascular diagnoses, and participant geographical, socio-economic, and ethnic background compared to the UK general pregnant population. Findings from the pilot study will inform subsequent phases of PREG-HEART, which will explore associations between different cardiovascular diagnoses and adverse cardiovascular, obstetric, and neonatal events. We will work closely with patients and clinicians to define priority research questions and use the PREG-HEART platform to support a range of observational and interventional studies to address these. Ethics: This study was approved by the West Midlands Solihull Research Ethics Committee. Registration details: PREG-HEART has been registered prospectively on the ISRCTN registry (ISRCTN11700499)