Early multi-chamber atrial dysfunction as a marker of subclinical cardiotoxicity in breast cancer patients: a prospective 2D speckle-tracking study

Background

Chemotherapy-induced cardiotoxicity is traditionally defined by a decline in left ventricular (LV) ejection fraction. However, subclinical injury often precedes LV dysfunction and involves the entire heart. Left atrial (LA) strain has emerged as a potentially sensitive marker for early myocardial remodelling.

Purpose

We aimed to assess the impact of sequential anthracycline and taxane therapy on atrial mechanics using two-dimensional speckle-tracking echocardiography (2D-STE).

Methods

We conducted a prospective, longitudinal study, including 111 women (mean age50.3 ±9.9 years) with invasive breast cancer receiving chemotherapy between September 2024 and December 2025. Patients with baseline structural heart disease, significant valvular disease, or LVEF < 40% were excluded. Echocardiography was performed at baseline (T0) and after chemotherapy completion (T1). The primary endpoint was the 2D-STE-derived LA reservoir strain.

Results

Following therapy, a significant reduction was observed in LA reservoir strain (median 35.0% vs. 31.5%; p < 0.001) and LA contractile strain (-16.0% vs. -14.0%; p < 0.001).

This functional decline was accompanied by significant LA structural remodelling, with an increase in LA volume index (LAVi) from 24.1 to 30.9 mL/m² (p < 0.001).

Atrial involvement was global, characterized by a significant decrease in right atrial reservoir strain (34.0% vs. 32.0%; p = 0.003).

LA conduit strain did not show a significant change (-19.0% vs -17.0%; p = 0.103).

Conclusion

Sequential anthracycline and taxane chemotherapy is associated with early and global atrial involvement. The impairment of both left and right atrial reservoir strains, alongside volumetric remodelling, suggests that atrial mechanics are highly sensitive markers for the detection of subclinical cardiotoxicity.