Longitudinal Diastolic strain as Predictor for Systolic Dysfunction Among Active
Breast Cancer Patients

Background: Cardio-toxicity, defined as a left ventricular ejection fraction reduction, is a significant side effect of cancer therapy. Global longitudinal systolic strain (GLS) has been shown to identify early systolic dysfunction in patients with active cancer. Although diastolic dysfunction is common among cancer patients, no evidence has been shown that it predicts systolic dysfunction. Early diastolic strain rate is considered to be a predictor of cardiac events in the general population; however, longitudinal diastolic strain (Ds) was not evaluated among cancer patients.

Objectives: The aim of this study was to evaluate the correlation of Ds with echocardiography filling pressure and to estimate its role in the early detection of cardio-toxicity among breast cancer patients.

Methods: Data were collected as part of the International Cardio-Oncology Registry (ICOR), enrolling all cancer patients evaluated at the cardio-oncology clinic in our institution. All patients preformed serial echocardiography, including GLS and Ds, at baseline and following therapy. GLS relative reduction of ≥11% was considered to be clinically significant. Ds was assessed as the early lengthening rate=diastolic slope (cm/sec²) and measured in 6 segments in each of the 3 apical views.

Results: A total of 69 patients (97% women, mean age 54±13years) with diagnosis of breast cancer were prospectively recruited. Significant GLS reduction was observed in 13% at 2^nd echo and 29% at 3^rd echo. Assessment of all Ds segments at 2^nd echo showed that four chamber mid septum (p=0.003), two chamber mid inferior (p=0.017) and two chamber base inferior (p=0.024) segments were all a significant predictor of GLS reduction at 3^rd echo. All of the mentioned segments had significant correlation with E/e` average (p=0.005, 0.009, 0.003) and E/A (p<0.001, <0.001, 0.005).

Conclusions: Among breast cancer patients, Ds showed high correlation to filling pressure parameters and emerged as significant early predictor for clinically significant systolic dysfunction.