Risk factors for heart disease change heart structure and appearance

Radiomics analysis of cardiac MRI scans.

Risk factors for heart disease including male sex, diabetes, high blood pressure, high cholesterol and smoking were linked to a darker appearance of the heart muscle, as well as a change in its texture.

For the study, researchers analysed images from heart magnetic resonance imaging (MRI) scans using a new toolkit called radiomics, developed in collaboration with the University of Barcelona, to get highly detailed information about the shape and texture of the heart.

Using their novel approach, the researchers studied heart MRI scans from almost 30,000 people from the UK Biobank - a large-scale biomedical database and research resource – to look at the overall shape and structure of the heart in detail. They found that for all the key risk factors studied the heart muscle was darker in appearance and had a smoother, less complex texture.  

Men were found to have larger hearts with the heart muscle appearing smoother and less texturally complex in comparison to women. The heart muscle in healthy women was brighter than male hearts with a more complex appearance of the muscle architecture, according to researchers.

Visualising the heart in greater detail

Current methods used to image the heart in hospitals are not able to fully reflect the complexity of the heart’s structure. By applying their new imaging toolkit to MRI scans the researchers were able to look at the structure and texture of the heart in much greater detail than is possible using existing standard techniques.

Dr Zahra Raisi-Estabragh, NIHR Clinical Lecturer in Cardiology at Queen Mary and lead author, said: “Our findings provide new insights into the impact of risk factors on the heart and identify differences in the size, structure, and appearance of hearts between healthy men and women. The study forms part of our wider research programme aimed at developing the radiomics imaging toolkit to transform patient care. Our novel approach has the potential to provide faster, more accurate diagnosis of heart disease, improve our estimations of future risk of heart conditions, and better understand the processes underlying cardiovascular disease.”

The researchers are now exploring whether the observed changes in heart muscle translate to higher risk of having significant heart problems, such as heart attacks. “As we’ve shown that these changes are associated with known major risk factors for heart disease, it’s very likely that they represent unhealthy changes to the heart muscle. However more research is needed to confirm this,” added Dr Raisi-Estabragh.

Using MRI scans to detect and predict disease

Imaging the heart is very important for the detection and prediction of heart disease. And the current gold standard method for imaging the heart is with a heart magnetic resonance imaging (MRI) scan.

As the main pumping chamber of the heart is the left ventricle, this has been the focus for both research and decision making in hospital to date. The smaller left atrium, which sits above and is in direct communication with the left ventricle, is highly sensitive to pressure changes in the left ventricle and it is thought that changes in the structure and function of the left atrium may precede those in the left ventricle. However, until now the value of heart MRI measures of the left atrium for detection and prediction of disease independent of the left ventricle had not been studied in large samples.

In a recent study, Dr Raisi-Estabragh and colleagues examined measures of these two heart chambers from heart MRI scans taken from 26,000 participants from the UK Biobank and assessed their relationship to key heart diseases and to the risk of death.

“We found that measures from both the left ventricle and left atrium were good indicators of both current and future disease. Our findings suggest that paying greater attention to changes in structure and function of the left atrium could be important for predicting and detecting disease in both research and clinical settings,” concludes Dr Raisi-Estabragh.

More information

• Research publication: ‘Cardiac magnetic resonance radiomics reveal differential impact of sex, age, and vascular risk factors on cardiac structure and myocardial tissue’ Raisi-Estabragh et al. Frontiers in Cardiovascular Medicine (2021) DOI:10.3389/fcvm.2021.763361
• More information on radiomics image analysis technique can be found in the following review paper: ‘Cardiac magnetic resonance radiomics: basic principles and clinical perspectives,’ Raisi-Estabragh et al. (2020) DOI: 10.1093/ehjci/jeaa028