Abstract 17722: Ventricular-Vascular Coupling Predicts Cardiotoxicity in Breast Cancer Patients Treated With Doxorubicin or Trastuzumab
Background: Doxorubicin and trastuzumab (Herceptin®) are used widely in the treatment of many cancers and have led to important survival gains, but carry a significant risk of cardiovascular (CV) morbidity. Furthermore, current metrics used to identify patients at increased CV risk, and the perturbations in ventricular-vascular mechanics that occur with cancer therapy remain poorly defined. The objective of this study was to determine if absolute values or interval changes in ventricular-arterial (VA) coupling are associated with cardiotoxicity in patients treated with doxorubicin and/or trastuzumab.
Methods: In 132 breast cancer patients treated with doxorubicin, trastuzumab, or the two agents sequentially, echocardiography was obtained prior to, during, and after completion of therapy at multiple standardized intervals. We derived quantitative measures of ejection fraction (EF), end-systolic elastance (Ees,sb), effective arterial elastance (Ea), and VA coupling (Ea/Ees,sb). Cardiotoxicity was defined by the Cardiac Review and Evaluation Committee criteria. We used generalized estimating equations with an exchangeable correlation structure to determine the association between Ea, Ees,sb, and Ea/Ees,sb and risk of cardiotoxicity.
Results: The mean age was 49±11 years, 65% were Caucasian, and 32% had a history of hypertension. Over a maximum follow-up of 2.2 years, 44% of the participants developed cardiotoxicity. Both the absolute values of Ea/Ees,sb (OR 3.2, 95% CI 1.7-6.0, p<0.001) and baseline changes in Ea/Ees,sb (OR 4.6, 95% CI 1.8, 11.7, p=0.002) were associated with cardiotoxicity (Fig. 1). Similar relationships were observed for Ea (p<0.05), but not Ees,sb (p>0.05).
Conclusions: In breast cancer patients treated doxorubicin and/or trastuzumab, absolute values and baseline changes in VA coupling are associated with cardiotoxicity. With further study, VA coupling may be important indicator of CV prognosis in these patients.
- © 2013 by American Heart Association, Inc.