A recent study from UCL (University College London) suggests that women might be overlooked for a serious heart condition diagnosis because current guidelines fail to consider fundamental differences in sex and body size.
The study, featured in the Journal of the American College of Cardiology and funded by the British Heart Foundation, proposes modifications to existing guidelines, showing that a personalized approach enhances diagnostic precision.
When researchers examined 1,600 patients diagnosed with hypertrophic cardiomyopathy (HCM), they discovered their revised technique significantly aided women, improving identification rates by 20 percentage points.
This fresh method evaluates individuals’ age, sex, and size to assess whether their heart muscle is excessively thick. Not only does this approach prevent missed diagnoses, but it could also lower the chances of misdiagnosing individuals with HCM.
Approximately one in 500 people in the UK suffers from HCM, a hereditary condition characterized by the thickening of the heart’s muscular wall, which impairs its ability to circulate blood. It can lead to severe issues like abnormal heart rhythms, potentially resulting in cardiac arrest and sudden death.
Traditionally, men constitute about two-thirds of HCM diagnoses; however, researchers claim that women have an equal likelihood of having the condition. There isn’t a universal test for diagnosing HCM; doctors rely on various tests and imaging results, with the critical measurement being the thickness of the left ventricle wall, which is the heart’s main pumping chamber.
For the past 50 years, the established threshold for diagnosing HCM has remained at 15 millimeters for everyone. If the muscle exceeds this thickness, a patient is labeled likely to have HCM.
Dr. Hunain Shiwani from the UCL Institute of Cardiovascular Science and St Bartholomew’s Hospital, who led the study, stated, “The existing threshold, which relies on data from studies from the 1970s, requires reevaluation. Having a uniform cut-off for all, regardless of age, sex, or size, overlooks how significantly these factors influence heart wall thickness.”
“This research offers a necessary update, demonstrating that a tailored approach enhances diagnostic precision. With effective HCM treatments becoming available, it’s crucial to accurately identify those who need them.”
The team utilized an AI tool they created to analyze MRI heart scans with remarkable accuracy and efficiency. The tool processed 5,000 MRI scans of healthy hearts and measured the thickness of the left ventricle wall. This enabled the researchers to establish normal wall thickness for various ages, sexes, and sizes, evaluated by body surface area.
This approach helped set thresholds for identifying abnormal wall thickness indicative of HCM based on an individual’s age, sex, and size. The threshold was higher for older and larger individuals or men and lower for younger, smaller individuals or women.
Testing these new thresholds on HCM patients, they then applied them, alongside the existing 15 mm standard, to a dataset of more than 43,000 UK Biobank participants.
Under the current threshold, only one out of every eight individuals identified with potential HCM was a woman. The identified individuals were also typically taller, heavier, and older than the average population.
Applying the new personalized thresholds resulted in a reduced overall number of identified cases, suggesting fewer misdiagnoses. Notably, this method led to a more balanced distribution between genders, with women accounting for 44% of those identified, which aligns more accurately with the equal prevalence of HCM in both sexes.
By factoring in additional important elements like ethnicity and ensuring the new thresholds align with echocardiogram scans — which are more widely used in clinical settings — the research team aims to facilitate the swift adoption of personalized guidelines by medical practitioners across Europe and America.
Dr. Sonya Babu-Narayan, Clinical Director at the British Heart Foundation and a clinical cardiologist, remarked, “Hypertrophic cardiomyopathy is a serious, potentially fatal condition, and missed diagnoses mean patients who could benefit from new and effective treatments may be overlooked. Additionally, receiving a diagnosis can be life-changing, making it imperative to avoid misdiagnoses.”
“By moving away from the traditional one-size-fits-all model, this study redefines the parameters for abnormal heart wall thickness, a significant factor in diagnosing hypertrophic cardiomyopathy. Consequently, more women and smaller individuals are being recognized who would have previously gone underdiagnosed.”
“While other diagnostic criteria are also crucial, this tailored approach to determining abnormal heart muscle thickness marks a new era for accurate diagnoses for patients and families impacted by hypertrophic cardiomyopathy.”
