IS RIGHT HEART FUNCTION ADVERSELY AFFECTED IN BREAST CANCER PATIENTS UNDERGOING ANTHRACYCLINE-BASED CHEMOTHERAPY?

Abstract

Cardiotoxicity from anthracycline-based chemotherapy is the second leading cause of death in breast cancer patients. Left ventricular function is routinely monitored during therapy to identify cardiotoxicity, however, animal studies suggest that right ventricular (RV) function may also be impaired and potentially allow earlier detection of cardiotoxicity because the thinner RV may be more sensitive to the toxic effects. The purpose of this pilot study was to determine if breast cancer patients undergoing anthracycline-based chemotherapy experience RV dysfunction. 50 breast cancer patients undergoing chemotherapy (receiving at least 240mg/m2 of anthracycline) at The Ottawa Hospital with 2 echocardiograms separated by an interval of at least 3 months were retrospectively identified between November 2007 and March 2013. Right atrial area (RAA), Right ventricular fractional area change (RV FAC) and RV longitudinal-strain of the free wall (RV LSFW)(Figure 1) were evaluated according to the American Society of Echocardiography right heart guidelines. The majority (48/50) of patients were females with an average age of 53.4 years (95% CI: 50.2 to 56.6 years). From baseline to follow-up study, average LV ejection fraction (LVEF) decreased from 62.8% (95% CI: 59.3 to 66.3) to 57.8% (95% CI: 54.5 to 61.1) (p<0.01). During the same time period, the mean RAA increased from 12.0cm2 (95% CI: 11.1 to 13.0cm2) to 13.9 cm2 (95% CI: 12.8 to 14.9cm2) (P = 0.0004), mean RV FAC decreased (P = 0.04) from 46.97% (95% CI: 43.20 to 50.73) to 41.75% (95% CI: 38.18 to 45.31%) and mean RV LSFW increased from -15.7% (95% CI: -17.7 to -13.7%) to -13.4% (95% CI: -14.9 to -11.9%)(P = 0.03). This pilot study confirms that RAA, RV FAC and RV LSFW are adversely affected in breast cancer patients undergoing anthracycline-based chemotherapy. Further studies are required to determine the implications of these adverse effects on right heart function and whether they can provide an earlier marker of cardiotoxicity.