Author + information
- Gherardo Finocchiaro, MD,
- Harshil Dhutia, BSc, MBBS,
- Andrew D’Silva, MBBS,
- Aneil Malhotra, MBBS, PhD, MSc,
- Alexandros Steriotis, MD, PhD,
- Lynne Millar, MBBS,
- Keerthi Prakash, MBBS,
- Rajay Narain, MBBS,
- Michael Papadakis, MBBS,
- Rajan Sharma, BSc, MBBS, MD and
- Sanjay Sharma, BSc, MBChB, MD∗ ()
- ↵∗St. George’s University of London, Cardiovascular Sciences, Cranmer Terrace, London SW17 0RE, United Kingdom
We are grateful to Dr. Pressler for his interest in our paper (1). We would like to start by disagreeing that there is a wealth of data on cardiac dimensions in female athletes and would argue the opposite especially when comparisons are made with data on male athletes. The issue of scaling metrics and sex differences in body size composition is challenging, and its application is a source of contention. Our study relates to the effects of sex and sporting discipline on left ventricular (LV) geometry, a parameter without a dimension (1). According to international guidelines (2), LV geometry is calculated using an equation that includes the LV end-diastolic diameter, LV wall thickness, and LV mass. The LV mass is indexed for body surface area (BSA) with different cutoff values for males and females. LV geometry is neither a description of a dimension or a numerical parameter, but it simply defines a shape; therefore, the issue of appropriate scaling is less relevant in this setting. We concede that LV mass indexed for BSA is part of LV geometry calculation, but an intrinsic correction for sex, with different cutoff values is also factored into the formula. Interestingly, in our cohort, the proportion of athletes exceeding LV mass/BSA was 24% both in males and females. The lack of difference between the sexes suggests that scaling LV mass for BSA using the cutoff values of 95 g/m2 in females and 115 g/m2 in males is a reliable method of identifying individuals with truly increased LV mass. This information can be derived easily and applied in day-to-day clinical practice.
Pressler et al. (3) studied 1,051 competitive athletes, including 271 female athletes, and reported that LV mass scaled for fat-free mass (FFM) was higher in male athletes compared with female athletes. However, because of the lack of established cutoff values for LV mass and/or FFM, the investigators were unable to determine the proportion of males and females with increased LV mass. The absence of defined and agreed cutoff values for scaling methods different from BSA are due to the paucity of robust studies in large populations. Moreover, the methods to calculate the FFM varies considerably, from skinfold thickness measurements to dual energy x-ray absorptiometry or use of magnetic resonance, with differing results according to the modality used (4). Finally, there is no solid consensus that FFM is the best method to scale cardiac dimensions. With this degree of uncertainty, we believe that the enthusiasm for using FFM should be moderated until large studies confirm its potential value.
We believe that our study provides an intriguing perspective on sex differences in LV geometry in athletes, suggesting that cardiac adaptation to exercise is different in males and females, particularly those engaged in dynamic sports. Because this may be a key to understanding the strikingly higher prevalence of sudden cardiac death in male athletes, further studies should be focused on this concept.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2017 American College of Cardiology Foundation
- Finocchiaro G.,
- Dhutia H.,
- D’Silva A.,
- et al.
- Giraldeau G.,
- Kobayashi Y.,
- Finocchiaro G.,
- et al.