Mediastinal radiation therapy for breast cancer in female patients is an independent risk factor for atrial fibrillation recurrence post-catheter ablation

Atrial Fibrillation in Patients with Breast Cancer: A Literature Review

In addition to traditional risk factors, patients with breast cancer are at an increased risk of atrial fibrillation due to cancer itself and certain cancer therapies. Atrial fibrillation in these patients adds to their morbidity and mortality. The precise mechanisms leading to the increased atrial fibrillation in patients with breast cancer are not well understood. The main goal of atrial fibrillation management in this population is to facilitate uninterrupted cancer treatment while addressing the arrhythmia and other cardiovascular sequelae of cancer treatment. Rhythm control is often challenging to implement in patients with breast cancer during active antineoplastic therapy because of the need for uninterrupted anticoagulation, potential drug-drug interactions between cancer treatments and antiarrhythmic medications, and the increased likelihood of atrial fibrillation recurrence. Prevention of thromboembolism and anticoagulation can also be challenging in patients with breast cancer as a result of the increased risk of cancer-related procoagulant state and coagulopathies. The integration of a cardio-oncology team and a multidisciplinary approach are crucial for better outcomes. The therapeutic interventions should be tailored toward individual patients' profiles through a shared decision-making approach. The precise mechanisms leading to the increased atrial fibrillation in patients with breast cancer are not well understood, highlighting the gaps in our knowledge. More research is required to reduce these gaps, refine risk stratification, and optimize treatment strategies in these patients.

Epidemiology, risk factors and mechanism of breast cancer and atrial fibrillation

Cancer and cardiovascular diseases are leading causes of death worldwide. Among them, breast cancer is one of the most common malignancies in women, while atrial fibrillation is one of the most extensively studied arrhythmias, with significant public health implications. As the global population ages and advancements in cancer treatments continue, the survival rates of breast cancer patients have significantly improved, leading to an increasing coexistence of breast cancer and atrial fibrillation. However, the mechanisms underlying this coexistence remain insufficiently studied, and there is no consensus on the optimal treatment strategies for these patients. This review consolidates existing research to systematically explore the epidemiological characteristics, risk factors, and pathophysiological mechanisms of both breast cancer and atrial fibrillation. It focuses on the unique signaling pathways associated with different molecular subtypes of breast cancer and their potential impact on the mechanisms of atrial fibrillation. Additionally, the relationship between atrial fibrillation treatment medications and breast cancer is discussed. These insights not only provide essential evidence for the precise prevention and management of atrial fibrillation in breast cancer patients but also lay a solid theoretical foundation for interdisciplinary clinical management practices.

Significant Influence of Cardiac Radiation Dose on the Risk of Cardiotoxicity in Patients Receiving Adjuvant Trastuzumab and Radiation Therapy for Breast Cancer

PURPOSE

This study aimed to analyze the incidence of cancer therapy-related cardiovascular toxicity (CTRCVT) and identify the radiation dosimetric and clinical risk factors for these events in patients with human epidermal growth factor receptor 2-positive breast cancer.

METHODS AND MATERIALS

Data from 1378 patients who were treated with curative surgery and adjuvant trastuzumab for breast cancer were retrospectively analyzed. A total of 959 patients underwent postoperative radiation therapy (RT), whereas 419 patients were managed without RT (no-RT). CTRCVT were categorized according to the time of occurrence in relation to trastuzumab as follows: during trastuzumab cycles (CTRCVT-during T) or after completing trastuzumab (CTRCVT-after T). The cardiac radiation dose was extracted from the RT plan of each individual patient. The incidence of and contributing factors for CTRCVT-during T and -after T were evaluated.

RESULTS

After a median follow-up of 95.8 months (range, 4.3-181.1 months), 69 patients (5.0%) had experienced CTRCVT. CTRCVT-during T was detected in 41 patients (3.0%), and the 8-year rate of CTRCVT-after T was 2.2%. Of the patients developing CTRCVT-during T, 27 (2.0%) discontinued trastuzumab. The cardiac radiation doses were significantly associated with the risk of both CTRCVT-during T (odds ratio, 1.087; P = .001) and -after T (hazard ratio, 1.177; P < .001). The 8-year rates of CTRCVT-after T were not significantly different between the no-RT and RT groups (2.0% vs 2.4%, P = .956). However, the rate was significantly higher in patients with heart V25Gy ≥3% compared with those with heart V25Gy <3% (5.7% vs 1.5%, P = .019). Patients who received <17 cycles of trastuzumab had worse oncological outcomes than those who received ≥17 cycles.

CONCLUSIONS

Both CTRCVT-during T and -after T were associated with the cardiac radiation dose. Therefore, evaluation of the cardiac radiation dose is necessary to prevent early termination of trastuzumab treatment, which could lead to worse outcomes.

Radiation-associated cardiovascular disease in patients with cancer: current insights from a cardio-oncologist

Radiation-associated cardiovascular disease (RACD), a complex disease characterized with pericarditis, myocardial damage, valvular heart diseases, heart failure, vasculopathy and ischemic heart disease, has a generally poor prognosis. While RACD may be acute, it often manifests in the late years or even decades following radiation exposure to the chest. With an increasing number of cancer survivors, RACD is likely to become an important issue in cardio-oncology. This review discusses pre-radiation therapy (RT) preparation, peri-RT patient management and long follow-up planning post-RT from a cardiology perspective. Additionally, a novel technique of stereotactic radiotherapy, which has been applied for the treatment of intractable cardiac arrhythmias, is presented. Appropriate patient examination and management during and after RT are essential to support patients undergoing cancer treatment to improve long life expectancy. A multidisciplinary team is needed to determine how to manage patients who receive RT to reduce RACD, to detect early phases of RACD and to provide the best treatment for RACD. Recent studies increasingly report advances in diagnosis using new equipment that has the potential to detect early phases of RACD, along with growing evidence for the optimal treatment for RACD. This review provides an overview of recent studies and guidelines to report on the latest findings, and to identify unresolved issues surrounding RACD that require validation in future studies.

Safety and efficacy of catheter ablation for atrial fibrillation in cancer survivors: a systematic review and meta-analysis

BACKGROUND

Cancer survivors are at increased risk for atrial fibrillation (AF). However, data on the efficacy and safety of catheter ablation (CA) in this population remain limited. Therefore, we aimed to perform a systematic review and meta-analysis comparing outcomes after CA for AF in patients with versus without prior or active cancer.

METHODS

We systematically searched PubMed, Cochrane Library, and Embase from inception to April 2023 for studies comparing the safety and efficacy of CA for AF in cancer survivors. Outcomes of interest were bleeding events, late AF recurrence, and need for repeat ablation. Statistical analyses were performed using Review Manager 5.4.1. We pooled odds ratios (OR) with 95% confidence intervals (CI) for binary endpoints.

RESULTS

We included 5 retrospective cohort studies comprising 998 patients, of whom 41.4% had a history of cancer. Cancer survivors were at significantly higher risk of clinically relevant bleeding (OR 2.17; 95% CI 1.17-4.0; p=0.01) as compared with those without cancer. The efficacy of CA for AF was similar between groups. Late AF recurrence at 12 months was not significantly different between patients with vs. without a history of cancer (OR 1.29; 95% CI 0.78-2.13; p=0.32). Similar findings were observed in the outcome of repeat ablations (OR 0.71; 95% CI 0.37-1.37; p=0.31).

CONCLUSIONS

These findings suggest that cancer survivors have an increased risk of bleeding after CA for AF relative to patients without cancer, with no significant difference in the efficacy of CA for maintenance of sinus rhythm between groups.

STUDY REGISTRATION

This systematic review is registered in the International Prospective Register of Systematic Reviews (PROSPERO) under registration number CRD42023394538.

Interventional Cardio-Oncology: Unique Challenges and Considerations in a High-Risk Population

OPINION STATEMENT

Patients with cancer are at risk of developing cardiovascular disease (CVD) including atherosclerotic heart disease (AHD), valvular heart disease (VHD), and atrial fibrillation (AF). Advances in percutaneous catheter-based treatments, including percutaneous coronary intervention (PCI) for AHD, percutaneous valve replacement or repair for VHD, and ablation and left atrial appendage occlusion devices (LAAODs) for AF, have provided patients with CVD significant benefit in the recent decades. However, trials and registries investigating outcomes of these procedures often exclude patients with cancer. As a result, patients with cancer are less likely to undergo these therapies despite their benefits. Despite the inclusion of cancer patients in randomized clinical trial data, studies suggest that cancer patients derive similar benefits of percutaneous therapies for CVD compared with patients without cancer. Therefore, percutaneous interventions for CVD should not be withheld in patients with cancer, as they may still benefit from these procedures.