Assessment of Radiation-Induced Malfunction in Cardiac Implantable Electronic Devices

Cardiac Toxicities in Oncology: Elucidating the Dark Box in the Era of Precision Medicine

Despite current advancements in chemotherapy, immunotherapy and targeted treatments, the potential for major adverse cardiovascular events, regardless of previous cardiac history, persists. Scoring systems, such as the Heart Failure Association-International Cardio-Oncology Society (HFA-ICOS) risk assessment tool, can be utilized to evaluate several factors including prior cardiac history, risk factors and cardiac biomarkers to categorize patients into low, moderate, high, and very high-risk groups. Common cardiotoxicity complications include new or worsening left ventricular ejection fraction (LVEF), QT interval prolongation, myocardial ischaemia, hypertension, thromboembolic disease, cardiac device malfunction and valve disease. Baseline electrocardiogram (ECG) and transthoracic echocardiogram (TTE) are routinely performed for all patients commenced on cardiotoxic treatment, while other imaging modalities and biochemical markers have proven useful for monitoring. Management mainly includes early risk stratification and prompt identification of cardiovascular complications, with patient-specific surveillance throughout treatment. A multidisciplinary approach is crucial in determining the relationship between potential treatment benefits and cardiotoxicity, and whether the continuation of treatment is appropriate on a case-by-case basis. Early risk stratification, optimizing the patient's cardiovascular status prior to treatment, and prompt identification of suspected cardiotoxicity are key in significantly reducing risk. This article provides a comprehensive review of the various types of treatment-related cardiotoxicity, offering guidance on identifying high-risk patients, recognizing early signs of cardiotoxicity, and outlining appropriate treatment approaches and follow-up care for such cases.

Impact of Radiotherapy on Malfunctions and Battery Life of Cardiac Implantable Electronic Devices in Cancer Patients

PURPOSE

This study analyses a large number of cancer patients with CIEDs for device malfunction and premature battery depletion by device interrogation after each radiotherapy fraction and compares different guidelines in regard to patient safety.

METHODS

From 2007 to 2022, a cohort of 255 patients was analyzed for CIED malfunctions via immediate device interrogation after every RT fraction.

RESULTS

Out of 324 series of radiotherapy treatments, with a total number of 5742 CIED interrogations, nine device malfunctions (2.8%) occurred. Switching into back-up/safety mode and software errors occurred four times each. Once, automatic read-out could not be performed. The median prescribed cumulative dose at planning target volume (PTV) associated with CIED malfunction was 45.0 Gy (IQR 36.0-64.0 Gy), with a median dose per fraction of 2.31 Gy (IQR 2.0-3.0 Gy). The median maximum dose at the CIED at time of malfunction was 0.3 Gy (IQR 0.0-1.3 Gy). No correlation between CIED malfunction and maximum photon energy (p = 0.07), maximum dose at the CIED (p = 0.59) nor treatment localization (p = 0.41) could be detected. After excluding the nine malfunctions, premature battery depletion was only observed three times (1.2%). Depending on the national guidelines, 1-9 CIED malfunctions in this study would have been detected on the day of occurrence and in none of the cases would patient safety have been compromised.

CONCLUSION

Radiation-induced malfunctions of CIEDs and premature battery depletion are rare. If recommendations of national safety guidelines are followed, only a portion of the malfunctions would be detected directly after occurrence. Nevertheless, patient safety would not be compromised.

Incidence and Predictors of Cardiac Implantable Electronic Devices Malfunction with Radiotherapy Treatment

Aims: To investigate the incidence of cardiac implantable electronic devices (CIED) malfunction with radiotherapy (RT) treatment and assess predictors of CIED malfunction. Methods: A 6-year retrospective analysis of patients who underwent RT with CIED identified through the radiation oncology electronic database. Clinical, RT (cumulative dose, dose per fraction, beam energy, beam energy dose, and anatomical area of RT) and CIED details (type, manufacturer, and device malfunction) were collected from electronic medical records. Results: We identified 441 patients with CIED who underwent RT. CIED encountered a permanent pacemaker (PPM) (78%), cardiac resynchronization therapy—pacing (CRT-P) (2%), an implantable cardioverter defibrillator (ICD) (10%), and a CRT-defibrillator (CRT-D) (10%). The mean cumulative dose of RT was 36 gray (Gy) (IQR 1.8–80 Gy) and the most common beam energy used was photon ≥10 megavolt (MV) with a median dose of 7 MV (IQR 5–18 MV). We further identified 17 patients who had CIED malfunction with RT. This group had a higher cumulative RT dose of 42.5 Gy (20–77 Gy) and a photon dose of 14 MV (12–18 MV). None of the malfunctions resulted in clinical symptoms. Using logistic regression, the predictors of CIED malfunction were photon beam energy use ≥10 MV (OR 5.73; 95% CI, 1.58–10.76), anatomical location of RT above the diaphragm (OR 5.2, 95% CI, 1.82–15.2), and having a CIED from the ICD group (OR 4.6, 95% CI, 0.75–10.2). Conclusion: Clinicians should be aware of predictors of CIED malfunction with RT to ensure the safety of patients.