A First Diastolic Function Evaluation in the Personalized Exercise Prescription Program for Solid Organs Transplanted Subjects: Is Atrial Strain Useful?

Abstract

Background/Objectives: Solid organ transplant recipients (OTR) have been recently involved in exercise prescription programs in order to reduce the high prevalence of cardiovascular diseases. The normal systolic and diastolic cardiac function is fundamental to personalizing the prescription. Diastolic dysfunction can be associated to a higher risk of cardiovascular events and left atrial (LA) strain is an emerging parameter in the evaluation of diastolic compromising, especially in subjects with preserved ejection fraction. Left atrial (LA) strain has never been explored in this category. The study aimed to evaluate the contribution of the LA strain in the assessment of diastolic function of OTR and its potential contribution in the exercise program. Methods: 54 solid OTR (liver and kidney transplants) regularly trained for at least 12 months in a home-based, partially supervised model at moderate intensity estimated by cardiopulmonary exercise test, underwent a complete echocardiographic analysis. The measured variables included left ventricle systolic function (ejection fraction, EF), diastolic function (E/A and E/E'), LA indexed volumes, LA peak atrial longitudinal strain (PALS) and LA peak atrial contraction strain (PACS). The data were compared to those of 44 healthy subjects (HS). Results: The OTR showed an overweight condition (BMI: 25.79 ± 2.92 vs. 22.25 ± 2.95; p < 0.01). Both groups showed a preserved systolic function (EF: OTR 63.1 ± 3.5% vs. HS 66.9 ± 6.1; p < 0.001), while diastolic standard parameters were significantly different (E/A, 1.01 ± 0.4 vs. 1.96 ± 0.74; p < 0.001; E/E', 9.2 ± 2.7 vs. 6.9 ± 1.3; p < 0.001, in OTR and HS respectively) despite being normal. LA strain was significantly lower in OTR vs. HS (4C PALS, 33.7 ± 9.7 vs. 45.4 ± 14.19; p < 0.001; 4C PACS, 15.9 ± 6.7 vs. 11.6 ± 7.5; p = 0.006; 2C PALS, 35.3 ± 11.1 vs. 47.6 ± 14.9; p < 0.001; 2C PALS, 17.4 ± 4.9 vs. 13.2 ± 14.97; p = 0.001; in OTR and HS respectively). A specific correlation of two- and four-chamber PACs and PALs with BMI has been observed (R for 4C PALS -0.406 ** and 2C PALS -0.276 *). Conclusions: These findings suggest that the coexistence of increased bodyweight in asymptomatic OTR patients can exacerbate the impairment of LA strains. LA strain detection could be useful in the development of a personalized exercise program for OTRs, especially for asymptomatic subjects and those with elevated cardiovascular risk profile, to potentially manage the exercise program in the long term. Larger studies will confirm the role via an eventual structured clinical score index.