Evaluation of traditional and novel echocardiographic methods of cardiac diastolic dysfunction post radiotherapy in breast cancer.

BACKGROUND

To investigate alterations in left ventricular (LV) diastolic function using traditional and novel echocardiographic parameters, following radiation therapy (RT) in breast cancer patients in the acute setting.

METHODS

40 chemotherapy-naïve women with left-sided breast cancer undergoing RT were prospectively recruited. A comprehensive transthoracic echocardiogram (TTE) was performed at baseline, during RT and 6weeks post-RT. Traditional echocardiographic diastolic parameters and diastolic strain rate were measured and analysed. The relationship between alterations in diastolic parameters, changes in global longitudinal systolic strain (GLS) and radiation dose were investigated.

RESULTS

Traditional diastolic parameters remained largely unchanged; however diastolic strain parameters, E-Sr and A-Sr were significantly reduced 6weeks post-RT [Longitudinal E-Sr (s) 1.47+/-0.32 vs 1.29+/-0.27*; Longitudinal A-Sr (s) 1.19+/-0.31 vs 1.03+/-0.24*; *p<0.05 vs baseline]. When patients were divided by a reduction ≥10% versus <10% in GLS post-RT, a greater reduction in both traditional diastolic and diastolic strain parameters was observed in the group with >10% reduction in systolic function as evaluated by GLS. When patients were divided by mean v30 dose, a greater % change in E-Sr was noted in those receiving more than mean V30 dose.

CONCLUSION

Diastolic dysfunction was only evident acutely, post-RT with the use of newer methods like strain analysis. A significant reduction in diastolic function was seen in the patient subgroup with ≥10% reduction in systolic function, enhancing the notion of diastolic function as a potential indicator for systolic dysfunction. Future longitudinal studies are required to determine the specific prognostic value of these observations.