The Utility of Advanced Cardiovascular Imaging in Cancer Patients-When, Why, How, and the Latest Developments

Redefining anthracycline-related subclinical cardiotoxicity: 'Absolute' and 'relative' change in longitudinal strain

AIMS

Anthracycline chemotherapy (AC) for breast cancer can cause cancer therapy-related cardiac dysfunction (CTRCD) with resultant heart failure, traditionally defined as a reduction in left ventricular (LV) ejection fraction on echocardiography. In recent years, global longitudinal systolic strain (GLS) has been used to identify subclinical cardiac dysfunction prior to development of overt CTRCD. Recent harmonized guidelines have incorporated GLS into definitions for CTRCD to identify cardiac dysfunction and inform decisions regarding cardioprotective strategies.

METHODS AND RESULTS

We evaluated subclinical dysfunction in breast cancer patients treated with AC and determined the echocardiographic and patient factors associated with significant GLS changes. One hundred fourteen HER2 negative patients treated with AC were prospectively recruited and underwent serial echocardiograms (LVEF and LVGLS) at three time points (prior to AC, 3 months, and 1 year). CTRCD was defined as an asymptomatic reduction in LVEF of 10% or symptomatic drop of 5% to LVEF <53%. Subclinical LV dysfunction was defined as a reduction of ≥10% in GLS compared with baseline, recognizing that this cut off identified an 'at risk cohort' rather than patients with established CTRCD. No participant demonstrated CTRCD by reduction in LVEF. Forty-three patients (38%) demonstrated a ≥10% relative reduction in GLS at 12 months; 20/43 (47%) had a reduced absolute GLS to <16%, and were older, had hypertension, increased LV mass, lower baseline e' velocity and GLS. GLS ≥20.5% at baseline yielded a sensitivity of 79% and specificity of 87% for a normal GLS (i.e., ≥16%) at 1 year despite a ≥10% reduction from baseline.

CONCLUSIONS

We present a stepwise evaluation for subclinical LV dysfunction using both a relative reduction in GLS combined with an absolute reduction in GLS. We believe our findings may re-stratify patients with a high baseline GLS into a lower risk group despite transient relative GLS decrements ≥10%.

Diastolic function assessment with left atrial strain in long-term survivors of childhood acute lymphoblastic leukemia

INTRODUCTION AND OBJECTIVES

Survivors of childhood cancer might be at increased risk of diastolic dysfunction at follow-up due to exposure to cardiotoxic treatment. Although assessment of diastolic function is challenging in this relatively young population, left atrial strain might provide a novel insight in this evaluation. Our aim was to examine diastolic function in a cohort of long-term survivors of childhood acute lymphoblastic leukemia by using left atrial strain and conventional echocardiographic parameters.

METHODS

Long-term survivors who were diagnosed at a single center between 1985 and 2015 and a control group of healthy siblings were recruited. Conventional diastolic function parameters and atrial strain were compared, and the latter was measured during the 3 atrial phases: reservoir (PALS), conduit (LACS) and contraction (PACS). Inverse probability of treatment weighting was used to account for differences between the groups.

RESULTS

We analyzed 90 survivors (age, 24.6±9.7 years, time since diagnosis 18 [11-26] years) and 58 controls. PALS and LACS were significantly reduced compared with the control group: 46.4±11.2 vs 52.1±11.7; P=.003 and 32.5±8.8 vs 38.2±9.3; P=.003, respectively. Conventional diastolic parameters and PACS were similar between the groups. The reductions in PALS and LACS were associated with exposure to cardiotoxic treatment in age- and sex-adjusted analysis (≥ moderate risk, low risk, controls): 45.4±10.5, 49.5±12.9, 52.1±11.7; Padj=.003, and 31.7±9.0, 35.2±7.5, 38.2±9.3; Padj=.001, respectively.

CONCLUSIONS

Long-term childhood leukemia survivors showed a subtle impairment of diastolic function that was detected with atrial strain but not with conventional measurements. This impairment was more pronounced in those with higher exposure to cardiotoxic treatment.

Development of a comprehensive cardiac atlas on a 1.5 Tesla Magnetic Resonance Linear Accelerator

Background and purpose

The 1.5 Tesla (T) Magnetic Resonance Linear Accelerator (MRL) provides an innovative modality for improved cardiac imaging when planning radiation treatment. No MRL based cardiac atlases currently exist, thus, we sought to comprehensively characterize cardiac substructures, including the conduction system, from cardiac images acquired using a 1.5 T MRL and provide contouring guidelines.

Materials and methods

Five volunteers were enrolled in a prospective protocol (NCT03500081) and were imaged on the 1.5 T MRL with Half Fourier Single-Shot Turbo Spin-Echo (HASTE) and 3D Balanced Steady-State Free Precession (bSSFP) sequences in axial, short axis, and vertical long axis. Cardiac anatomy was contoured by (AS) and confirmed by a board certified cardiologist (JR) with expertise in cardiac MR imaging.

Results

A total of five volunteers had images acquired with the HASTE sequence, with 21 contours created on each image. One of these volunteers had additional images obtained with 3D bSSFP sequences in the axial plane and additional images obtained with HASTE sequences in the key cardiac planes. Contouring guidelines were created and outlined. 15-16 contours were made for the short axis and vertical long axis. The cardiac conduction system was demonstrated with eleven representative contours. There was reasonable variation of contour volume across volunteers, with structures more clearly delineated on the 3D bSSFP sequence.

Conclusions

We present a comprehensive cardiac atlas using novel images acquired prospectively on a 1.5 T MRL. This cardiac atlas provides a novel resource for radiation oncologists in delineating cardiac structures for treatment with radiotherapy, with special focus on the cardiac conduction system.

Challenges in Cardiovascular Imaging in Women with Breast Cancer

Cardiovascular imaging in breast cancer patients is paramount for the surveillance of cancer therapy-related cardiac dysfunction (CTRCD); however, it comes with specific limitations. PURPOSE OF REVIEW: This review aims to describe the unique challenges faced in cardiovascular imaging of breast cancer patients, discuss evidence to support the utility of various imaging modalities, and provide solutions for improvement in imaging this unique population. RECENT FINDINGS: Updated clinical society guidelines have introduced more unifying surveillance of CTRCD, although there remains a lack of a universally accepted definition. Traditional and novel multi-modality imaging can be used to detect CTRCD and myocarditis in breast cancer patients. Cardiovascular imaging in breast cancer patients is difficult due to reconstructive surgery. Although echocardiography with myocardial strain is the cornerstone, multi-modality imaging can be used to evaluate for CTRCD and myocarditis. Novel imaging techniques to improve the diagnosis of cardiotoxicities in breast cancer patients are needed.

Cardiac magnetic relaxometry versus ejection fraction in anthracycline-related cardiac changes: a systematic review and meta-analysis

PURPOSE

The purpose of this meta-analysis is to compare the magnitude of the changes in left ventricular ejection fraction (LVEF) and cardiac magnetic resonance (CMR) relaxometry techniques soon after the completion of anthracycline therapy. Anthracyclines are associated with myocardial functional and morphological changes. LVEF is currently used to identify the functional changes. Anthracyclines can also cause myocardial inflammation and oedema. This can be assessed using CMR relaxometry techniques; T1 and T2 mapping and extracellular volume (ECV) fraction.

METHODS

Three databases were systematically searched for studies evaluating CMR relaxometry parameter at baseline and 1±1 months after anthracycline completion (the last search date 17 March 2023). CMR parameters pre and post anthracycline-based chemotherapy were abstracted. A random effects model was used to pool mean difference (MD) in LVEF and ECV. Standardised mean difference (SMD) was also calculated for T1 and T2 mapping due to the variations in techniques, normal ranges and for the comparison among the parameters.

RESULTS

A total of 296 patients were included from 10 studies. 84% were female with a mean age of 54.9 years. Statistically significant alterations were observed in LVEF (MD -3.38% (95% CI -5.13%, -1.62%)) and ECV (1.92% (1.30%, 2.53%)). The pooled SMDs were also significant in LVEF, T1, T2 and ECV with -0.61 (-0.91, -0.30), 0.53 (0.16, 0.90), 0.59 (0.22, 0.96) and 0.74 (0.41, 1.06), respectively.

CONCLUSIONS

Our meta-analysis demonstrated small but significant alterations in CMR relaxometry parameters soon after anthracycline therapy, where ECV was superior to LVEF and T1 or T2 mapping. However, these short-term MDs were below the minimal detectable differences.

PROSPERO REGISTRATION NUMBER

CRD42020196296.

The Role of Multimodality Cardiac Imaging in Patients Undergoing Cancer Treatment

PURPOSE OF REVIEW

Modern therapeutics have led to improved survival for many types of cancer but have also been associated with adverse effects including potentially life-threatening cardiotoxicities. We sought to review the uses of multimodality cardiac imaging for risk stratification, prevention, and identification of cardiotoxicities in patients undergoing cancer treatment.

RECENT FINDINGS

Advancements in both echocardiography and emerging modalities, like cardiac magnetic resonance imaging and cardiac computed tomography, continue to improve the pre- and during therapy cardiac evaluation of cancer patients. Echocardiography and cardiac magnetic resonance imaging, with the incorporation of global longitudinal strain, can identify overt and subclinical cancer therapy-related cardiac dysfunction and myocarditis, and stress echocardiography and cardiac computed tomography can noninvasively screen and monitor for coronary artery disease. Multimodality cardiac imaging is an evolving and critical tool for the pre-therapy screening and risk stratification, as well as during therapy surveillance of cancer treatment-related cardiotoxicity.

Increased Prevalence of Fragmented QRS in Randomly Selected Group of Multiple Myeloma Patients: A Pilot Study to Assess Prevalence

The presence of fragmented QRS (fQRS) on surface electrocardiograms (ECGs) has been associated with the myocardial scar in certain cardiac conditions and has been proposed as a potential marker of adverse cardiac outcomes. Since myocardial fibrosis not only has been recognized as a side effect of certain cancer therapies but also, fQRS have been shown in some breast cancer and lymphoma survivors post-chemotherapy treatment, we decided to investigate if fQRS could also be seen in multiple myeloma (MM) patients since this association has never been described. For this pilot study, we analyzed ECGs from 137 randomly selected MM patients during different stages of their treatment, and fRQS was found in 42% of these cases. The prevalence was much higher than the reported prevalence for the general population (19.0%) but closer to that reported for patients with myocardial infarction (39.5%). We also found that female MM patients are more commonly affected than women in the general population. Based on this small random sampling analysis, fQRS appears highly prevalent among unselected MM patients. This novel finding of fQRS in MM patients certainly adds to the growing data of cases among different cancer patients, opening the door to conduct larger prospective studies that undoubtedly will help to create a more robust database regarding the potential utility of this ECG abnormality.