Up to 10% of babies across the world are born before the full 37 weeks of pregnancy are completed. This is known as preterm birth, and large-scale studies have found that people born preterm are at risk of developing heart disease as they reach young adulthood.
A team led by Dr Adam Lewandowski is working to understand how the heart and vascular system develops differently in these people throughout their life-span, compared to their peers born after a full-term pregnancy. Dr Lewandowski and others have previously shown that people born preterm, as a group, have altered left ventricular structure and function of the heart, as well as a higher blood pressure. But the relationship between these two factors was still unclear.
Now, in a study published in JAMA Cardiology, Dr Lewandowski and his team studied magnetic resonance images of the heart from 468 young adults. Two hundred of these adults were born preterm.
In multivariable regression analyses of systolic blood pressure and left ventricular mass, the slope of the relationship was steeper in adults born preterm. In particular, young adults born very and extremely preterm (<32 weeks of gestation, which is known to be put them at greatest risk of heart disease) had a 2.5-fold greater change in left ventricular mass per 1-mmHg systolic blood pressure elevation, compared to their term-born peers. Similarly, left ventricular mass indexed to end-diastolic volume was 3.3-fold greater per 1-mmHg systolic blood pressure elevation compared to adults born at term.
“We had hypothesised that adults born preterm would have greater changes in left ventricular remodelling as blood pressure went up”, said Dr Afifah Mohamed, first author on the study who recently completed her DPhil in RDM. “What surprised us was the magnitude of the change with blood pressure elevation, particularly in those born more preterm.”
Dr Adam Lewandowski, senior author on the study and a PI in RDM’s Division of Cardiovascular Medicine who supervised Dr Mohamed, added: “The current study adds to the growing body of evidence that young adults born preterm have a potentially adverse cardiac phenotype. Our finding that blood pressure elevation may have a greater impact on heart remodelling in the preterm-born population emphasises the importance of long-term clinical follow-up of these individuals.”
Dr Lewandowski and his team are currently working on additional studies to better understand the development of these cardiac changes and underlying mechanisms, including longitudinal follow-up of these young adults as part of the #SELFIE study.
The study was funded by the British Heart Foundation and Wellcome Trust.
Read the full study.