Myocardial work index in endurance athletes with lack of expected left ventricular eccentric hypertrophy remodelling
Authors: Di Gioia G , Ortolina D , Maestrini V , Monosilio S , Squeo M R , Lemme E , Serdoz A , Fiore R , Zampaglione D , Pelliccia A 
Published: June 2024

Abstract

Background
Endurance elite athletes are expected to present a cardiac remodelling typically characterized by left ventricle (LV) eccentric hypertrophy (EH). However, clinical practice shows that not all endurance athletes present a cardiac remodelling.
The global myocardial work index (GWI), combining myocardial deformation with non-invasive afterload determination, has proven to be afterload-independent and related to myocardial deformation and contractile function and have been shown to be reliable in distinguishing between physiological adaption and pathological changes in the athletes’ heart.

Purpose
Aim our study was to identify elite endurance athletes without cardiac remodelling and characterize GWI to evaluate as lack of remodelling has subclinical LV pathological aspects.

Methods
We studied 96 endurance Olympic athletes, mean age 27.4±7 years, 63 (67.7%) male. Athletes practiced different disciplines including: 9 athletics (&gt;800 mt, marathon, long-distance track&field), 14 canoeing, 37 rowing, 13 cycling, 11 Kayak, 9 long-distance swimming, 3 pentathlon. Athletes were submitted to clinical, anthropometrics, cardio-pulmonary exercise stress test (CPET) and transthoracic echocardiogram (TTE). Strain rate and GWI was performed and the following parameters collected: global longitudinal strain (GLS), GWI, constructive myocardial work (CMW), wasted myocardial work (WMW) and global cardiac work efficiency (GWE). Left ventricle (LV) remodelling was defined as normal geometry (NG) or concentric remodelling (CR) as left LV mass (LVM) £115 g/m2 in male, £95 g/m2 in female and respectively relative wall thickness (RWT) £0.42 and &gt;0.42; concentric hypertrophy (CH) or eccentric hypertrophy (EH) as LVM &gt;115 g/m2 in male or &gt;95 g/m2 in female and respectively RWT &gt;0.42 and £ 0.42. All athletes were enrolled during off-season period.

Results
Athletes presented the following LV remodelling: 39 (40.6%) EH, 57 (59.4%) NG, 0% CH and CR.
Athletes with NG trained for less hours (21.6±8.2 vs. 25.9±8, p=0.025) and presented lower functional indexes on CPET (lower watt max 310.1±76.5 vs. 382.2±92.5, p=0.0002; lower Vo2 max, mL/min/kg 49.3± 8.1 vs. 53.3±9.3, p=0.037) with similar arrhythmic burden. At TTE, a lower global morphological remodelling was observed in NG with lower bi-ventricular and bi-atrial diameter and volumes, but with similar GLS -20.3±2 vs. -19.3±6.4%, p=0.100) and MWI; GWI: 1852.5±284.7 vs. 1913.3±252.7 mmHg, p=0.295; GCW: 2205.3±330.5 vs. 2300.4±295 mmHg, p=0.160; GWW: 88.6±47.9 vs. 100.4±53.4 mmHg, p=0.272 and GWE: 95.6±2 vs. 95.4±2%, p=0.596).

Conclusions
Athletes showing lack of expected remodelling have reduced morpho-functional parameters but with similar GWI, suggesting absence of pathological substrate. A more individualized assessment, with tailored training strategies could optimize athletic potential. CPET differences. TTE Differences.