A new international, multi-center study has developed a cardiac magnetic resonance imaging model to predict "functional heart age" and quantify premature cardiovascular aging in patients with common risk factors, such as hypertension, diabetes mellitus, and obesity.
The researchers analyzed cardiac magnetic resonance (CMR) data from 563 subjects across five centers globally to create a mathematical model that estimates heart age based on left atrial (LA) measurements. The derivation cohort included 191 healthy individuals with normal body mass index (BMI) and no cardiovascular risk factors, whereas 366 patients with risk factors (BMI greater than 25 kg/m², hypertension, diabetes mellitus (DM), atrial fibrillation [AF], and hyperlipidaemia) comprised the group for validation. The age range for participants spanned 10 to 85 years and was stratified by decade.
“This study highlights the time course of structural and physiological changes in the heart during healthy and unhealthy ageing,” wrote the authors, led by Hosamadin S. Assadi of the University of East Anglia.
In healthy individuals, CMR-derived functional heart age closely matched chronological age. In contrast, in patients with cardiovascular risk factors, functional heart age exceeded chronological age by a mean of 4.6 years.
The researchers found a dose-dependent relationship between obesity severity and heart aging. While normal-weight and overweight subjects showed no significant difference between functional and chronological heart age, individuals with obesity exhibited progressive premature aging: 4 years older in Class I obesity, 5 years in Class II, and 45 years in Class III.
“We propose simple equations that should help communicate subtle changes in heart assessment with ageing,” the researchers noted in their conclusion.
Methodology and Key Findings
The study used artificial intelligence (AI)-integrated batch segmentation to process CMR images, which ensured precise automated measurement of cardiac parameters. After comprehensive analysis, LA end-systolic volume (ESV) and LA ejection fraction (EF) emerged as the strongest predictors of functional heart age. The final model used three regression equations to estimate heart age based on LA ESV ranges (less than 15 mL, 15 to 50 mL, more than 50 mL), with additional correction thresholds for LA EF. For example, when LA EF was less than 55%, 20 years were added to the estimated heart age.
Disease-specific patterns of functional heart age were identified:
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Patients with hypertension exhibited premature aging until the seventh decade of life.
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Diabetic patients showed an initial exaggeration of heart age in the third decade, which peaked in the fourth decade and then declined gradually.
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Patients with AF had significantly higher functional heart age across all age groups.
“By demonstrating the discrepancy in cardiac and functional age, CMR-derived functional heart age might highlight patients in need of risk factor interventions and help simplify concepts for patients,” the authors remarked on the clinical potential.
Cardiac Chamber-Specific Aging
The study documented detailed age-related changes across the four cardiac chambers:
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Left atrium: Volume progressively increased across the lifespan, with steep rises in the third and eighth decades, while LA EF declined from 66% to 55%.
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Right atrium: Volume increased linearly with age, and efficiency as both reservoir and pump declined from the end of the second decade.
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Left ventricle: End-systolic and end-diastolic volumes declined across the lifespan, while EF rose gradually, with a steep increase after the seventh decade.
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Right ventricle: Volumes oscillated with peaks in the third and seventh decades and a trough in the fifth decade.
“Present guidelines set a dichotomous LVEF threshold of 50%, above which the LVEF, and therefore the systolic function, is considered preserved,” the authors wrote. “Our findings raise the question of whether these thresholds need to be adjusted according to the patient’s age.”
Source: European Heart Journal Open