Optimizing Longitudinal Cardiac Monitoring in Breast Cancer Chemotherapy

Chemotherapy-induced cardiotoxicity (CIC) remains a significant barrier to treatment adherence and long-term quality of life for patients with breast cancer. Presented at the 2026 American Psychosocial Oncology Society (APOS) Annual Meeting, a Brazilian prospective study conducted from 2022 to 2024 followed 50 patients with stage I to III breast cancer through 6 cycles of chemotherapy to assess the evolution of cardiac injury. By comparing baseline (T1) and post-treatment (T6) data, researchers aimed to validate the use of Troponin I, C-reactive protein (CRP), and electrocardiographic (ECG) parameters as early indicators of cardiovascular risk.

Top 5 Clinical Takeaways

1. Significant Doubling of QTc Prolongation Risk

   1. The prevalence of QTc prolongation increased significantly from 13.04% at baseline to 26.09% after 6 cycles of chemotherapy (P <.001). This doubling of prevalence suggests a substantial increase in arrhythmic risk during the standard course of treatment.

2. Marked Elevation of Myocardial Injury Markers

   1. Troponin I levels showed a 5-fold increase, rising from a mean of 2.22 ± 4.05 ng/mL at T1 to 11.43 ± 25.91 ng/mL at T6 (P <.001). The peak recorded value of 126.1 ng/mL underscores the presence of progressive myocardial injury in this population.

3. Increased Arrhythmia Prevalence

   1. The study observed a 3-fold increase in arrhythmias, which rose from 4.35% to 13.04% over the treatment period. Despite these electrical changes, heart rate remained stable in the vast majority (93.48%) of patients, suggesting that rhythm disturbances may be more sensitive indicators than heart rate alone.

4. Inflammatory Markers Remained Statistically Stable

   1. While CRP levels did trend upward—increasing from 3.25 ± 3.56mg/L to 5.69 ± 11.56 mg/L—the change was not statistically significant (P = 0.238). This suggests that Troponin I and ECG changes may be more specific early markers for CIC than general inflammatory markers like CRP.

5. Requirement for Integrated Cardiac Surveillance

   1. The findings highlight a critical need for routine cardiologic assessment and continuous monitoring throughout the chemotherapy journey. Early detection through Troponin I and ECG monitoring allow for the implementation of cardioprotective strategies, which are essential to improving oncological outcomes and reducing long-term complications.

“Patients [with breast cancer] undergoing chemotherapy showed Troponin I elevation and QTc prolongation, raising the risk of CIC. The increase in arrhythmias and ECG abnormalities highlights the need for continuous cardiac monitoring and early intervention. Routine cardiologic assessment and cardioprotective strategies may improve outcomes and reduce complications,” lead study author Naira Santos D’Agostini, from Federal University of Espírito Santo in Brazil, wrote with coauthors in the poster. “Further research is needed to optimize cardiac surveillance in oncology populations.”

Investigators evaluated patients at a Brazilian oncology referral center. Statistical analyses were performed via McNemar and Wilcoxon signed-rank tests to assess variables including heart rhythm, heart rate, QTc interval, T-wave abnormalities, atrioventricular blocks, and atrial fibrillation.

Patients had a mean age of 53.3 ± 11.4 years. There was an equal distribution of patients with ductal carcinoma in situ and those with invasive ductal carcinoma (50%). Most of the study population had stage II disease (62%). Additionally, most patients received adjuvant chemotherapy regimens (58%) followed by neoadjuvant regimens (42%).

Reference

D’Agnostini NS, Batista de Azevedo L, Neto LCBS, et al. Cardiotoxicity in breast cancer patients undergoing chemotherapy: longitudinal evaluation of electrocardiographic alteration and cardiac biomarkers. Presented at the 2026 American Psychosocial Oncology Society Annual Meeting, New Orleans, LA; March 18-20, 2026. Poster 87.