Background
Cardiomyopathy (disease of heart muscle) in pregnancy is a potentially life-threatening condition. It is becoming more common as more pregnancies are occurring in women who are older, or have pre-eclampsia (high blood pressure in pregnancy), multiple pregnancies such as twins, and multiple long-term health conditions. Although the short-term outlook is improving, some studies have suggested a link between cardiomyopathy in pregnancy and an increased chance of developing cancer in later life. However, we do not yet know how strong this link is, the types of cancers cardiomyopathy are associated with, or why there might be such a link.
Purpose
This study will assess how strong the link is between cardiomyopathy in pregnancy and developing cancer in the future. We will use routinely collected health information from the Clinical Practice Research Datalink to understand whether women with cardiomyopathy in pregnancy are more likely to develop cancer, and if so, how much more likely are they to develop cancer.
Potential importance of findings
This study will help to improve the health of women after cardiomyopathy by identifying the factors that are linked to increased risk of cancer. It may then be possible to reduce these health risks by follow-up of women following cardiomyopathy, assessment of risk factors for cancer, with intervention to reduce risks.
Background
The incidence of peripartum cardiomyopathy is increasing, which may be due to the rising rates of advanced maternal age, pre-eclampsia, multiple pregnancies (which is partly due to increased use of assisted reproductive technologies) and comorbidities in women of reproductive age. Despite improvements in short-term prognosis, some studies have linked cardiomyopathy in pregnancy with an increased future risk of cancer. However, there have been no large-scale studies to confirm the association and to quantify the level of risk.
Objective
To investigate the associations between peripartum cardiomyopathy and future diagnosis of cancer.
Methods
Using a comparative cohort design, we will compare women with and without cardiomyopathy (exposure), who had pregnancies between 1987 and 2017. They will be followed for future cancer until incident event, 31st December 2019, last data collection or until they no longer contribute to CPRD due to leaving practice, death, or the practice leaving CPRD.
Data analysis
The baseline cancer risk factors will be compared between women with and without cardiomyopathy, using Chi-squared tests for categorical variables and t-tests for continuous variables. The independent associations between peripartum cardiomyopathy and future cancer will be investigated using Cox proportional hazards model, adjusting for other potential risk factors. We will then assess differences in strength of the association of other risk factors with cancer between women with and without peripartum cardiomyopathy using interaction terms.
(1) Any cancer.
(2) Site-specific cancers, to include the top 3 commonest cancers in UK females breast, lung and colon cancers.
(3) Cancer mortality.
Pensee Wu - Chief Investigator - Keele University
James Bailey - Corresponding Applicant - Keele University
Carolyn Chew-Graham - Collaborator - Keele University
Kelvin Jordan - Collaborator - Keele University
Mamas Mamas - Collaborator - Keele University
Pensee Wu - Corresponding Applicant - Keele University
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Pregnancy Register