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)

WHAT IS ALREADY KNOWN ON THIS TOPIC

Cardiovascular disease in pregnancy is a leading cause of adverse health outcomes for both mothers and babies in the UK and its prevalence is rising.

Data to guide management of cardiovascular disease in pregnancy are limited, including how to care for women during pregnancy and the postpartum, the impact of maternal disease on pregnancy outcomes, and the effect of pregnancy on long-term cardiovascular health.

Because individual conditions (e.g. specific cardiomyopathies or congenital lesions) are rarely encountered within single maternity units, existing studies are small, underpowered, and restricted to highly selected patient groups from a small number of large units.

WHAT THIS STUDY ADDS

PREGnancy, HEART Health, and Cardiovascular Disease (PREG-HEART) is a planned national, prospective, data-enabled cohort and platform study.

Women with cardiovascular disease in pregnancy and healthy pregnant controls will be recruited via a direct-to-patient online platform, allowing entry of self-reported demographic and clinical data, consent to long-term data linkage, consent to recontact for additional studies and biosample collection.

This direct-to-patient approach is designed to overcome geographical and institutional barriers, ensuring that the cohort is diverse and representative of the wider UK population.

In an initial pilot phase, we will assess the feasibility of recruitment to PREG-HEART and describe the representativeness of our cohort with regards to the geographical, socio-economic and ethnic background of participants compared with the UK pregnant population.

The results of this pilot will inform a larger study which will leverage additional funding and utilise the PREG-HEART platform to enable aetiological studies and clinical trials that answer priority questions of patients and health care providers.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE, OR POLICY

We anticipate that this pilot study will lay vital groundwork and demonstrate the feasibility of direct-to-patient recruitment to an online pregnancy cohort.

This will inform future work to develop PREG-HEART as a unique national resource to support collaborative clinical and translational research, strengthen epidemiological evidence, and inform future strategies for the management of cardiovascular disease in pregnancy.

Graphical Abstract

The authors have declared no competing interest.

Study set-up and initial recruitment is supported by pump-priming funding from the NIHR-BHF Cardiovascular Partnership. This study is being supported by thehearthive.org. The Heart Hive is funded by Cardiomyopathy UK, Sir Jules Thorn Charitable Trust (21JTA), the BHF Big Beat Challenge award (BBC/F/21/220106), and the MRC/NIHR Rare Disease Research UK Cardiovascular Initiative (MR/Y008235/1). Additionally, the authors acknowledge the support of the Medical Research Council (MR/Z505092/1, MR/W023830/1), the British Heart Foundation (RE/18/5/34216, RE/24/130023), the Fetal Medicine Foundation (495237), the NIHR Imperial Biomedical Research Centre, and the Pumping Marvellous Foundation (charity number 1151848) and the EPSRC (EP/X03075X/1). The views expressed in this work are those of the authors and not necessarily those of the funders.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethics: This study was approved by the West Midlands Solihull Research Ethics Committee.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

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↵* KH and RB are co-first authors

↵** UT and ADM are co-senior authors

↵5 Patient co-author

All data produced in the present study are available upon reasonable request to the authors