Assessment of lateral costal artery with CT angiography: determination of prevalence and vessel length in the general population and its potential impact for coronary artery bypass grafting.

OBJECTIVES: Standard treatment for severe coronary artery disease (CAD) is coronary artery bypass grafting (CABG). An underreported branch of the internal mammary artery, the lateral costal artery (LCA), can cause a steal phenomenon after CABG, resulting in angina. The aim of this study was to determine the prevalence and length of LCA based on CT angiography (CTA). METHODS: This retrospective study included adult patients undergoing a thoracic CTA between January 2016 and August 2018. Exclusion criteria were prior CABG, insufficient clinical information, or inadequate image quality. Two blinded, independent readers reviewed all studies for the prevalence of the LCA. Positive cases were reviewed by two readers (R1/R2) for side distribution and vessel length, measured in intercostal spaces (ICS). Study indication, aortic size, and coronary calcification were noted. RESULTS: LCA was present in up to 42/389 (11%) of studies (60.3 ± 16.7 years, 30 males). The LCA was most commonly unilateral (n = 23, 55%). Median vessel length was 2 ICS (IQR 0; 3). Logistic regression was not significant in vessel distribution for sex (OR 0.6, 95% CI 0.28-1.15; p = 0.11). Inter-observer agreement in detecting LCA was substantial (kappa 0.71, 95% CI 0.59-0.83) and excellent for side/length distribution (kappa 0.94, 95% CI 0.82-1.0; ICC 0.96, 95% CI 0.93-0.98). CONCLUSION: The LCA is uncommon and most often unilateral and extends the third rib. Radiologists should be aware of this vessel and its potential role in angina after CABG, particularly when large. KEY POINTS: • LCA is an uncommon normal variant that is reported to cause angina pectoris after CABG. • CT angiography can reliably detect the LCA. It is most often unilateral and spans two intercostal spaces.

Cardiovascular magnetic resonance based diagnosis of left ventricular non-compaction cardiomyopathy: impact of cine bSSFP strain analysis.

BACKGROUND: Investigation of the myocardial strain characteristics of the left ventricular non-compaction (LVNC) phenotype with cardiovascular magnetic resonance (CMR) feature tracking. METHODS: CMR cine balanced steady-state free precession data sets of 59 retrospectively identified LVNC phenotype patients (40 years, IQR: 28-50 years; 51% male) and 36 healthy subjects (39 years, IQR: 30-47 years; 44% male) were evaluated for LV volumes, systolic function and mass. Hypertrabeculation in patients and healthy subjects was evaluated against established CMR diagnostic criteria. Global circumferential strain (GCS), global radial strain (GRS) and global longitudinal strain (GLS) were evaluated with feature-tracking software. Subgroup analyses were performed in patients (n = 25) and healthy subjects (n = 34) with normal LV volumetrics, and with healthy subjects (n = 18) meeting at least one LVNC diagnostic criteria. RESULTS: All LVNC phenotype patients, as well as a significant proportion of healthy subjects, met morphology-based CMR diagnostic criteria: non-compacted (NC): compacted myocardial diameter ratio > 2.3 (100% vs. 19.4%), NC mass > 20% (100% vs. 44.4%) and > 25% (100% vs. 13.9%), and NC mass indexed to body surface area > 15 g/m2 (100% vs. 41.7%). LVNC phenotype patients demonstrated reduced GRS (26.4% vs. 37.1%; p < 0.001), GCS (- 16.5% vs. -20.5%; p < 0.001) and GLS (- 14.6% vs. -17.1%; p < 0.001) compared to healthy subjects, with statistically significant differences persisting on subgroup comparisons of LVNC phenotype patients with healthy subjects meeting diagnostic criteria. GCS also demonstrated independent and incremental diagnostic value beyond each of the morphology-based CMR diagnostic criteria. CONCLUSIONS: LVNC phenotype patients demonstrate impaired strain by CMR feature tracking, also present on comparison of subjects with normal LV volumetrics meeting diagnostic criteria. The high proportion of healthy subjects meeting morphology-based CMR diagnostic criteria emphasizes the important potential complementary diagnostic value of strain in differentiating LVNC from physiologic hypertrabeculation.

Quantification of myocardial deformation by deformable registration-based analysis of cine MRI: validation with tagged CMR.

OBJECTIVES: To validate deformable registration algorithms (DRAs) for cine balanced steady-state free precession (bSSFP) assessment of global longitudinal strain (GLS) and global circumferential strain (GCS) using harmonic phase (HARP) cardiovascular magnetic resonance as standard of reference (SoR). METHODS: Seventeen patients and 17 volunteers underwent short axis stack and 2-/4-chamber cine bSSFP imaging with matching slice long-axis and mid-ventricular spatial modulation of magnetization (SPAMM) myocardial tagging. Inverse DRA was applied on bSSFP data for assessment of GLS and GCS while myocardial tagging was processed using HARP. Intra- and inter-observer variability assessment was based on repeated analysis by a single observer and analysis by a second observer, respectively. Standard semi-automated short axis stack segmentation was performed for analysis of left ventricular (LV) volumes and ejection fraction (EF). RESULTS: DRA demonstrated strong relationships to HARP for myocardial GLS (R2 = 0.75; p < 0.0001) and endocardial GLS (R2 = 0.61; p < 0.0001). GCS result comparison also demonstrated significant relationships between DRA and HARP for myocardial strain (R2 = 0.61; p < 0.0001) and endocardial strain (R2 = 0.51; p < 0.0001). Both methods demonstrated small systematic errors for intra- and inter-observer variability but DRA demonstrated consistently lower CV. Global LVEF was significantly lower (p = 0.0099) in patients (53.7%; IQR 43.9/64.0%) than in healthy volunteers (62.6%; IQR 61.1/66.2%). DRA and HARP strain data demonstrated significant relationships to LVEF. CONCLUSIONS: Non-rigid deformation method-based DRA provides a reliable measure of peak systolic GCS and GLS based on cine bSSFP with superior intra- and inter-observer reproducibility compared to HARP. KEY POINT: • Myocardial strain can be reliably analyzed using inverse deformable registration algorithms (DRAs) on cine CMR. • Inverse DRA-derived strain shows higher reproducibility than tagged CMR. • DRA and tagged CMR-based myocardial strain demonstrate strong relationships to global left ventricular function.

Immune checkpoint inhibitor-related myocarditis: an illustrative case series of applying the updated Cardiovascular Magnetic Resonance Lake Louise Criteria.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have improved outcomes for many types of cancer. However, ICI therapies are associated with the development of myocarditis, an immune-mediated adverse event associated with a high mortality rate. Therefore, prompt diagnosis and early intervention are of outmost importance. There is limited data on the application of cardiovascular magnetic resonance (CMR)-based modified Lake Louise Criteria (mLLC) with the use of relaxometry techniques for the diagnosis of ICI myocarditis. CASE SUMMARY: Four cancer patients undergoing ICI treatment presented with various clinical symptoms and troponin elevation to emergency/ambulatory clinics within 10-21 days after ICI initiation. On the suspicion of possible ICI-related myocarditis all patients underwent CMR within a few days after admission. Applying mLLC including relaxometry techniques, all patients met 'non-ischaemic injury criteria', while 3/4 patients met 'oedema criteria'. In most patients, quantitative mapping revealed substantially increased T1 values, while T2 values were only mildly increased or normal. In two patients with follow-up, CMR demonstrated improvement in findings after immunosuppressive treatment. However, there was only limited agreement between the degree of high-sensitive troponin levels and T1/T2 levels. DISCUSSION: The application of mLLC with T1/T2 mapping appears useful in the CMR diagnosis of acute ICI myocarditis with non-ischaemic myocardial injury criteria being the most common finding. The sensitivity of native T1 appears higher than T2 mapping in the acute diagnosis as well as in the assessment of treatment response. As troponin elevations may persist for some time with ICI myocarditis, CMR may represent an alternate strategy to monitor treatment response.

Serial Cardiovascular Magnetic Resonance Strain Measurements to Identify Cardiotoxicity in Breast Cancer: Comparison With Echocardiography.

OBJECTIVES: This study sought to compare the prognostic value of cardiovascular magnetic resonance (CMR) and 2-dimensional echocardiography (2DE) derived left ventricular (LV) strain, volumes, and ejection fraction for cancer therapy-related cardiac dysfunction (CTRCD) in women with early stage breast cancer. BACKGROUND: There are limited comparative data on the association of CMR and 2DE derived strain, volumes, and LVEF with CTRCD. METHODS: A total of 125 prospectively recruited women with HER2+ early stage breast cancer receiving sequential anthracycline/trastuzumab underwent 5 serial CMR and 6 of 2DE studies before and during treatment. CMR LV volumes, left ventricular ejection fraction tagged-CMR, and feature-tracking (FT) derived global systolic longitudinal (GLS) and global circumferential strain (GCS) and 2DE-based LV volumes, function, GLS, and GCS were measured. CTRCD was defined by the cardiac review and evaluation committee criteria. RESULTS: Twenty-eight percent of patients developed CTRCD by CMR and 22% by 2DE. A 15% relative reduction in 2DE-GLS increased the CTRCD odds by 133% at subsequent follow-up, compared with 47%/50% by tagged-CMR GLS/GCS and 87% by FT-GCS. CMR and 2DE-LVEF and indexed left ventricular end-systolic volume (LVESVi) were also associated with subsequent CTRCD. The prognostic threshold change in CMR-left ventricular ejection fraction and FT strain for subsequent CTRCD was similar to the known minimum-detectable difference for these measures, whereas for tagged-CMR strain it was lower than the minimum-detectable difference; for 2DE, only the prognostic threshold for GLS was greater than the minimum-detectable difference. Of all strain methods, 2DE-GLS provided the highest increase in discriminatory value over baseline clinical risk factors for subsequent CTRCD. The combination of 2DE-left ventricular ejection fraction or LVESVi and strain provided greater increase in the area under the curve for subsequent CTRCD over clinical risk factors than CMR left ventricular ejection fraction or LVESVi and strain (18% to 22% vs. 9% to 14%). CONCLUSIONS: In women with HER2+ early stage breast cancer, changes in CMR and 2DE strain, left ventricular ejection fraction, and LVESVi were prognostic for subsequent CTRCD. When LVEF can be measured precisely by CMR, FT strain may function as an additional confirmatory prognostic measure, but with 2DE, GLS is the optimal prognostic measure. (Evaluation of Myocardial Changes During BReast Adenocarcinoma Therapy to Detect Cardiotoxicity Earlier With MRI [EMBRACE-MRI]; NCT02306538).

Cardiovascular Magnetic Resonance Imaging: Identifying the Effects of Cancer Therapy.

The era of modern oncology incorporates an ever-evolving personalized approach to hematological malignancies and solid tumors. As a result, patient survival rates have, in part, substantially improved, depending on the specific type of underlying malignancy. However, systemic therapies may come along with potential cardiotoxic effects resulting in heart failure with increased morbidity and mortality. Ultimately, patients may survive their malignancy but die as a result of cancer treatment. Cardiovascular magnetic resonance imaging has long been in use for the assessment of function and tissue characteristics in patients with various nonischemic cardiac diseases. Besides an introductory overview on the general definition of cardiotoxicity including potential underlying mechanisms, this review provides insight into the application of various cardiovascular magnetic resonance imaging techniques in the setting of cancer therapy-related cardiac and vascular toxicity. Early identification of cardiotoxic effects may allow for on-time therapy adjustment and/or cardioprotective measures to avoid subsequent long-term heart failure with increased mortality.