Does diastolic dysfunction precede systolic dysfunction in trastuzumab-induced cardiotoxicity? Assessment with multigated radionuclide angiography (MUGA)

Trastuzumab is successfully used for the treatment of her2-positive breast cancer. because of its association with cardiotoxicity, lvef is monitored by muga, though this is a relatively late measure of cardiac function. diastolic dysfunction (dd) is believed to be an early predictor of cardiac impairment. we evaluate the merit of muga-derived diastolic function parameters in the early detection of trastuzumab-induced cardiotoxicity (tic). 77 trastuzumab-treated patients with normal baseline systolic and diastolic function were retrospectively selected (n = 77). all serial muga examinations were re-analyzed for systolic and diastolic function parameters. 36 patients (47%) developed sd and 45 patients (58%) dd during treatment. both systolic and diastolic parameters significantly decreased. of the patients with sd, 24 (67%) also developed dd. dd developed prior to systolic impairment in 54% of cases, in 42% vice versa, while time to occurrence did not differ significantly (p = .52). this also applied to the subgroup of advanced stage breast cancer patients (p = .1). trastzumab-induced sd and dd can be detected by muga. an impairment of muga-derived diastolic parameters does not occur prior to sd and therefore cannot be used as earlier predictors of tic.