Risk-stratified changes in left atrial strain during chemotherapy: preliminary data

Background Alterations in left atrial strain (LAS) may reflect early functional changes not captured by conventional cancer-therapy-related cardiac dysfunction indices. However, how LAS evolves during chemotherapy and whether its trajectory differs according to baseline cardiovascular risk remain unclear. Purpose To evaluate longitudinal changes in LAS during chemotherapy and to determine whether these changes differ according to baseline cardiovascular risk. Methods In a prospective cohort study, 71 women with breast cancer undergoing anthracycline based potentially cardiotoxic chemotherapy were stratified into low-risk (n=40) and moderate/high-risk (n=31) groups according to the HFA-ICOS risk assessment. LAS components corresponding to reservoir, conduit, and contractile function—expressed as peak atrial longitudinal strain (PALS), peak atrial conduit strain, and peak atrial contraction strain (PACS)—were assessed using speckle-tracking echocardiography at baseline, after 4 cycles, and after 8 cycles of chemotherapy following a standardized acquisition protocol. Longitudinal changes were analysed using linear mixed-effects models with random intercepts, including time, risk group, and time×group interaction as fixed effects. Where appropriate, within-group temporal changes were explored using Friedman tests with Bonferroni-adjusted post hoc comparisons. Results Across the entire cohort, significant time effects were observed for all LAS components (all p<0.001). PALS demonstrated similar trajectories in both risk groups, characterised by an early decline after 4 cycles with partial recovery by 8 cycles, with no evidence of a differential trajectory according to baseline risk (time×group p=0.927). In contrast, peak atrial conduit strain showed a significant time×group interaction (p=0.012), with greater impairment by the end of chemotherapy in the moderate/high-risk group compared with the low-risk group (Figure 1). Similarly, PACS demonstrated a significant time×group interaction (p=0.008), indicating more pronounced deterioration in atrial contractile function among patients with higher baseline cardiovascular risk (Figure 2). Conclusions LAS components exhibit dynamic changes during chemotherapy with distinct risk-dependent patterns. While LA reservoir function follows comparable trajectories regardless of baseline cardiovascular risk, conduit and contractile strain components demonstrate greater impairment in patients at moderate to high risk. These findings suggest that LAS analysis provides complementary information for early cardiac functional assessment in cardio-oncology beyond conventional ventricular indices.