Left ventricular end-diastolic volume as a new indexation method in athletes with aortic dilatation: a cardiac MRI study

Purpose Exercise-induced cardiac remodeling (EICR) may lead to increased aortic dimensions in athletes. ESC guidelines recommend indexation to BSA and height to correct for the influence of body size (1). However, these indexation methods fail to consider the potential impact of EICR on aortic size in athletes. We therefore aimed to investigate whether indexing aortic dimensions to left ventricular end diastolic volume (LVEDV), a marker of EICR, reclassifies athletes exceeding absolute thresholds for aortic dilatation. Methods Cross-sectional cardiac magnetic resonance imaging (CMR) study among elite-athletes that underwent routine screening (Olympic, national or international; ≥16 years; ≥10h exercise/week without a history of heart disease and no para-athletes). Athletes were categorized by sex and ESC sport category (endurance, mixed, power/skill). CMR included 3D whole heart in diastole (1.5T or 3T) for aortic measurements. Aortic root was measured at the sinus of Valsalva (maximal cusp-cusp measurement), and indexed to BSA, height, and LVEDV. Aortic dilatation was defined as >40 mm in men and >34 mm in women. Sex-specific Z-scores were calculated using the study cohort as reference population. Results In 404 elite athletes (41% women; median age 28.0 [24.0–32.0] years; 46% endurance) aortic root dilatation was present in 37 athletes (9.2%); 20 women (54%); 17 endurance (46%). Aortic root diameter correlated with LVEDV across sport categories (Spearman r = 0.61–0.70; all p < 0.001), also after adjustment for age and BSA (r = 0.28–0.47; p < 0.01). Among athletes exceeding absolute thresholds for aortic dilatation, 17.5% exceeded +2 SD after BSA indexation, 25% using height, and 10% using LVEDV. LVEDV-based indexation placed dilated athletes closer to the sex-specific physiological range. Sixteen endurance athletes with a dilated aortic root remained within 2 SD of normal range when indexed to LVEDV. Conclusion Indexation of aortic root dimensions to LVEDV reclassifies more athletes with an absolute dilated aortic root to normal or near 2SD physiological range than BSA or height indexation. Potentially, LVEDV-indexation might better reflect exercise-induced aortic remodeling, especially in endurance athletes. This may help distinguish physiological enlargement from true aortic pathology in athletes with a dilated root.