Use of myocardial strain imaging by echocardiography for the early detection of radiotherapy-induced cardiotoxicity in breast cancer patients (BACCARAT Study)

Sophie Jacob (1) , Valentin Walker (1) , Olivier Fondard (2) , Christian Chevelle (3) , Gaëlle Jimenez (3) , Marie Odile Bernier (1) , Dominique Laurier (4) , Jean Ferrieres (5) , Olivier Lairez (6)

1 IRSN/PSE-SANTE/SESANE/LEPID - Laboratoire d épidémiologie des rayonnements ionisants
2 Cardiologie générale et interventionnelle
3 RADIOTHÉRAPIE (ONCORAD)
4 IRSN/PSE-SANTE/SESANE - Service de recherche sur les effets biologiques et Sanitaires des rayonnements ionisants
5 Department of Cardiology B and Epidemiology
6 Service Cardiologie [CHU Toulouse]

Background: Radiotherapy (RT) is a major component of breast cancer treatment . However, breast RT is associated with long-term cardiac toxicity with clinical detection only relevant 10 to 15 years after RT. Early surrogate endpoints, predictive for the development of later cardiac events, would be useful. Purpose : To evaluate echocardiographic strain imaging for the detection of subclinical myocardial dysfunction arising after breast cancer RT. Methods: BACCARAT is a monocentric prospective cohort study of unilateral breast cancer patients treated with RT but without chemotherapy. They are followed for 2 years with repeated cardiac imaging examinations, including 2-dimensional speckle strain imaging for the detection of subclinical left ventricular abnormalities. Results : Between October 2015 and December 2017, this study prospectively included 114 women (95 left-sided and 19 right-sided) aged 58±8 years. Cardiac evaluations with strain imaging are performed before RT, 6 months and 24 months after RT. At this stage of the study, strain imaging measurements before RT and RT+6 months are available for 65 patients. Mean heart and left ventricle doses were 2.9 ± 1.3 Gy and 6.1 ± 2.9 Gy for the left-sided patients , 0.4 ± 0.1 Gy and 0.1 ± 0.04 Gy , respectively, for the right-sided patients. A decrease in global longitudinal strain was observed at 6 months post-RT for left-sided patients (-14.1% ±3.6% at 6 months after RT vs -15.4% ± 3.2% before RT, percentage of change 9.2%, P=0.02) but not for right-sided patients. No significant change was observed with conventional echocardiography left ventricular ejection fraction measurement. Conclusion : These preliminary results demonstrate a statistically significant reduction of global longitudinal strain 6 months after RT. Further investigation of BACCARAT study could illustrate strain imaging may have a potential role for screening and identification of patients at risk to develop cardiac complications.

Domaines: Sciences du Vivant [q-bio]

Sophie Jacob, Valentin Walker, Olivier Fondard, Christian Chevelle, Gaëlle Jimenez, et al.. Use of myocardial strain imaging by echocardiography for the early detection of radiotherapy-induced cardiotoxicity in breast cancer patients (BACCARAT Study). 29es Journées Européennes de la Société Française de Cardiologie / 29th European Days of the French Society of Cardiology, JESFC, Jan 2019, PARIS, France. pp.49-50, ⟨10.1016/j.acvdsp.2018.10.107⟩. ⟨hal-02463772⟩