Cardio-oncology & otherCohort study
Cardiac Substructure Radiation Dose and Associations With Tachyarrhythmia and Bradyarrhythmia After Lung Cancer Radiotherapy
- Retrospective cohort study
Authors' conclusion
This study revealed pathophysiologically distinct arrhythmia classes associated with radiotherapy dose to discrete cardiac substructures, including PV dose with AF and SVT, left circumflex coronary artery dose with atrial flutter, right coronary artery dose with bradyarrhythmia, and left main coronary artery dose with VT or asystole, guiding potential risk mitigation approaches.
Study context
- Population
- Patients with locally advanced non-small cell lung cancer treated with radiotherapy
- Participants
- 748 patients
- Exposure
- Cardiac substructure radiation dose and grade ≥3 arrhythmia classes
- Outcome
- CTCAE grade ≥3 AF, atrial flutter, other SVT, bradyarrhythmia, and VT or asystole, by cardiac substructure dose
Main finding
As reported in the abstract
Substructure dose associations with arrhythmia classes (adjusted for baseline CV risk; Fine-Gray, noncardiac death as competing risk)
Estimate (95% CI)P value
PV volume receiving 5 GyAF
sHR 1.04 /mL(1.01–1.08)
P = 0.016Left circumflex coronary artery volume receiving 35 Gyatrial flutter
sHR 1.10 /mL(1.01–1.19)
P = 0.028PV volume receiving 55 GySVT
sHR 1.03 per 1%(1.02–1.05)
P < 0.001Right coronary artery volume receiving 25 Gybradyarrhythmia
sHR 1.14 /mL(1.00–1.30)
P = 0.042Left main coronary artery volume receiving 5 GyVT or asystole
sHR 2.45 /mL(1.21–4.97)
P = 0.013Per 1%, as printed
Observational data: associations, not effects.
Further findings
Any grade ≥3 arrhythmia
- Patients with ≥1 grade ≥3 arrhythmia
- 128 (17.1%)
- Median time to first arrhythmia
- 2.0 years (Q1-Q3: 0.9-4.2 years)
2-year cumulative incidence by arrhythmia group
- Atrial fibrillation (AF)
- 8.0%
- Atrial flutter
- 2.7%
- Other supraventricular tachyarrhythmia (SVT)
- 1.8%
- Bradyarrhythmia
- 1.4%
- Ventricular tachyarrhythmia (VT) or asystole
- 1.1%
Original publication
Cardiac Substructure Radiation Dose and Associations With Tachyarrhythmia and Bradyarrhythmia After Lung Cancer Radiotherapy. JACC CardioOncol. Published 20 August 2024. doi:10.1016/j.jaccao.2024.07.005
Summarised from the published abstract; every number is checked against it