Journal of Cardiovascular Magnetic Resonance最新文献

Background: Mitral annular disjunction (MAD) is a controversial entity. Recently, a distinction between pseudo-MAD, present in systole and secondary to juxtaposition of the billowing posterior leaflet on the left atrial wall, and true-MAD, where the insertion of the posterior leaflet is displaced on the atrial wall both in diastole or in systole, has been proposed. We investigated the prevalence of pseudo-MAD and true-MAD.

Methods: This was a retrospective study, including consecutive patients referred to cardiovascular magnetic resonance (CMR). MAD was defined as a ≥1 mm displacement between the left atrial wall-mitral valve leaflet junction hinge and the top of the left ventricular wall, measured from cine-CMR images in the three long-axis views. Pseudo-MAD and true-MAD were defined as the presence of MAD only in systole or both in systole and diastole, respectively.

Results: Two hundred and ninety patients (59 [47-71] years; 181/290 men, 62%) were included. Mitral valve prolapse (MVP) and MAD were found in 24/290 (8%) and 145/290 (50%) patients, of which 100/290 (35%) with true-MAD and 45/290 (16%) with pseudo-MAD. In all measurements, systolic MAD extent (2.3 [1.7-3.0] mm) resulted equal to or greater than diastolic MAD extent (2.0 [1.5-2.9] mm). The most frequent MAD location was the inferior wall (117/290, 40%) and the inferolateral wall was the rarest (50/290, 17%). In patients with MVP, the prevalence of MAD was higher (21/24, 88%), mainly driven by a higher prevalence of pseudo-MAD, as the prevalence of true-MAD did not vary significantly in patients with vs without MVP (p = 0.22), except for the inferolateral wall (9/24, 38% vs 20/266, 8%; p < 0.001). The extent of pseudo-MAD was greater in patients with MVP (4.0 [3.0-5.6] mm) than in those without MVP (2.0 [1.5-3.0]; p < 0.001), whereas the extent of true-MAD did not differ significantly (2.5 [2.0-3.2] mm and 1.9 [1.5-2.9] mm; p = 0.06). At the inferolateral wall, the prevalence of pseudo-MAD was 7/24, 29% vs 14/266, 5% (p < 0.001) in patients with vs without MVP.

Conclusion: True-MAD was a common imaging finding in patients undergoing CMR, irrespective of MVP. Patients with MVP showed higher prevalence and extent of pseudo-MAD in all locations and true-MAD in the inferolateral wall.

With a prevalence of 2-3% in the general population, mitral valve prolapse (MVP) is the most common valvular heart disease. The clinical course is benign in the majority of patients, although severe mitral regurgitation, heart failure, and sudden cardiac death affect a non-negligible subset of patients. Imaging of MVP was confined to echocardiography until a few years ago when it became apparent that cardiovascular magnetic resonance (CMR) could offer comparative advantages for detecting and quantifying mitral valve abnormalities alongside tissue myocardial characterization. The present review highlights the growing body of evidence supporting the role of CMR in patients with MVP. Based on the recent literature, CMR appears not as a simple alternative to echocardiography in patients with poor acoustic windows, but as a complementary imaging modality instrumental for better quantifying mitral valve abnormalities, mitral regurgitation severity, ventricular remodeling, and myocardial tissue changes. In this respect, pivotal CMR studies highlight that mitral annular disjunction and myocardial fibrosis by late gadolinium enhancement are associated with a heightened risk of life-threatening ventricular arrhythmias (arrhythmic MVP). We also delineate how these and other markers (e.g., the severity of mitral regurgitation) could enable a personalized risk assessment in patients with MVP and implement clinical decision-making. Here, we provide a comprehensive review of the current literature, with an emphasis on the arrhythmic MVP phenotype. The review also provides some practical suggestions on how to carry out a dedicated CMR protocol in MVP and composes a thorough report to inform clinicians on key aspects of this valvular heart disease.

Background: Multiparametric cardiovascular magnetic resonance (CMR) has an emerging role in non-invasive surveillance of pediatric heart transplant recipients (PHTR). Higher myocardial T2, higher extracellular volume fraction (ECV), and late gadolinium enhancement (LGE) have been associated with adverse clinical outcomes in adult heart transplant recipients. The purpose of this study was to investigate the prognostic value of CMR-derived T1 and T2 mapping, ECV, and LGE for clinical outcomes in PHTR.

Methods: We performed a single-center, retrospective chart review of consecutive, gadolinium-enhanced CMR studies in PHTR over a 7.5-year period, excluding follow-up studies. Standard CMR ventricular volume and function analysis, T1 mapping with ECV, T2 mapping, and LGE assessment were performed. The composite outcome included cardiac death, non-cardiac death, re-transplantation, and cardiac hospitalization.

Results: Among 113 PHTR, mean age was 13.0 ± 5.1 years, with 6.0 ± 4.0 years since transplant. The indication for CMR was surveillance in 79%. Mean native T1 was 1050 ± 48 ms, T2 49.2 ± 3.9 ms, and ECV 29.7 ± 4.5%. Left ventricular LGE was present in 37% (42/113) and right ventricular LGE in 3.5% (4/113). The mean follow-up time was 2.3 years and median was 1.4 years. Cardiac death occurred in 2% (2/113), re-transplantation in 4% (4/113), and cardiac hospitalization in 22% (25/113). Non-cardiac death did not occur. Using Kaplan-Meier analysis, high T1 (≥1061 ms), T2 (≥50.0 ms), and ECV (≥31.4%) were each associated with decreased freedom from the composite outcome in follow-up. In univariable Cox regression analyses, high T1 was associated with increased risk of the composite outcome (hazard ratios [HR] 4.0, 95% confidence interval [CI] 1.7-9.2, p = 0.001), as were high T2 (HR 2.8, 95% CI 1.1-7.1, p = 0.026), and high ECV (HR 3.5, 95% CI 1.5-8.1, p = 0.004).

Conclusion: T1 and T2 mapping are associated with early differences in adverse cardiac events in PHTR. These data suggest a role for a multicenter study with a longer follow-up duration.

Background: Recent evidence underscores the importance of cardiovascular magnetic resonance (CMR) in light chain amyloidosis (AL amyloidosis). We aimed to comprehensively assess the prognostic significance of CMR parametric mapping in AL amyloidosis.

Methods: This prospective study consecutively included AL amyloidosis patients who underwent CMR imaging before therapy. The statistical analyses included T2, extracellular volume, and native T1 as variates under investigation, adjusted for well-established prognostic markers. The outcome was death from any cause.

Results: In total, 195 patients (age, 57.2 ± 9.1 years; male/female, 123/72) were recruited. At the median follow-up time (19 months), the survival probability was approximately 67.2% (131/195). T >44 ms, extracellular volume fraction (ECV) >47%, and native T1 >1468 ms were significantly prognostic (all, P < 0.05) but non-significant after adjustment for N-terminal pro-B-type natriuretic peptide (all, P > 0.05) in AL amyloidosis. T2 >44 ms was independently prognostic after correcting for left ventricle (LV) late gadolinium enhancement, LV ejection fraction, LV longitudinal strain, and therapeutic response (all, P < 0.05). In patients achieving deep hematologic response, T2 >44 ms (hazard ratios [HR] 6.611, 95% confidence interval [CI] 1.723-25.361, P = 0.006) was significantly prognostic for mortality after adjustment for cardiac response. Accordingly, T2 >44 ms was significantly associated with mortality (HR 5.734, 95% CI 1.189-27.656, P = 0.030) and remained independently prognostic after correcting for LV late gadolinium enhancement and LV longitudinal strain (both, P < 0.05) in patients who achieved both deep hematologic response and cardiac response.

Conclusion: This study highlights that T2 is a valuable independent predictor of mortality in an AL amyloidosis population, additive to common CMR risk factors. Moreover, myocardial edema assessment identified patients in need of adjunctive therapies, which is of particular prognostic significance in patients with deep therapeutic response.

Background: Cardiac involvement in light chain amyloidosis (AL) is the main determinant of prognosis. Amyloid can be deposited in the extracellular space and cause an increase in extracellular volume fraction (ECV). At the same time, amyloid can also be deposited in the wall of small vessels and cause microvascular dysfunction. This study sought to investigate the extent of microvascular dysfunction and its incremental prognostic value in cardiac light-chain amyloidosis (AL-CA) by quantitative stress perfusion.

Methods: A total of 126 AL amyloidosis patients (61.13 ± 8.46 years, 81 male) confirmed by pathology were prospectively recruited. All subjects underwent cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE), T1 mapping, and stress perfusion on a 3T scanner. ECV and myocardial perfusion reserve (MPR) were measured semi-automatically using a dedicated CMR software. Clinical, laboratory, and CMR parameters were analyzed for their prognostic value in the assessment of AL-CA patients. Mortality-associated markers were analyzed by univariate and multivariable Cox regression.

Results: The median follow-up time was 37 (33.6-40.4) months, and 62 patients died. The ECV of survivors was significantly reduced, but the stress myocardial blood flow and MPR were higher (P < 0.001). The MPR of the transmural LGE group was significantly lower than that of the no LGE and subendocardial LGE groups (P < 0.001). In multivariable analysis, ECV, MPR, and LGE were independently predictive. MPR of >1.5 and ECV of ≤53.6% were associated with improved overall survival, both of which provided predictive incremental value in patients with advanced disease. With equal Mayo staging and degree of ECV, MPR improves assessment of patient survival.

Conclusion: ECV and MPR showed additive incremental values and further discriminated prognosis of patients in advanced stages. CMR phenotypes with higher ECV and lower MPR had a worse prognosis.

Background: Patients with hypoplastic left ventricles (LV) who undergo volume-loading procedures (recruitment, biventricular [BIV] repair) are at risk for adverse outcomes, including heart failure and death. We investigated pre-BIV LV shape as a predictor of outcome after BIV repair in patients with hypoplastic LVs.

Methods: Baseline and post-recruitment cardiac magnetic resonance imaging and computed tomography data were analyzed in patients with hypoplastic LV (<50 mL/m²). Statistical shape modeling (SSM) was utilized to generate a model of the shape and variability of LVs. Traditional measures of LV sphericity and eccentricity were also measured. Major adverse cardiovascular events (MACE) included heart failure, transplant, and death.

Results: Of 95 patients with baseline mean LV volume 29 ± 13 mL/m², 45/95 (47%) had a right dominant atrioventricular canal defect, 31/95 (33%) had a variant of hypoplastic left heart syndrome, and 18/95 (19%) had endocardial fibroelastosis (EFE). A wide variation in LV shape was found by SSM, and shape modes were associated with right ventricle (RV) and LV size, and diagnosis. BIV repair was achieved in 74/95 (78%) patients; 13/74 (18%) of BIV patients had MACE. Predictors of MACE following BIV repair included EFE, higher RV mass index, and higher RV end-diastolic volume index. No baseline or post-recruitment LV shape parameter was associated with the outcome after BIV repair.

Conclusion: The shape model of hypoplastic LVs demonstrated a wide array of LV shapes. LVs gained sphericity and size and lost eccentricity with recruitment. Though the ventricles changed shape with recruitment, no specific LV shape characteristic at the baseline or post-recruitment stage was predictive of decision to proceed with BIV repair or outcome. Higher RV mass and volume may represent new biomarkers that predict outcomes following BIV repair in patients with hypoplastic LV. Further investigation could determine the reproducibility of these findings.

Background: Coronary microvascular dysfunction (CMD) is a significant complication in type 2 diabetes (T2D) and may be more common in women. We aimed to evaluate the sex differences and sex-specific clinical determinants of CMD in adults with T2D without prevalent cardiovascular disease.

Methods: Single center pooled analysis of four prospective studies comparing asymptomatic people with T2D and controls. All subjects underwent comprehensive cardiovascular phenotyping with myocardial perfusion reserve (MPR) quantified with perfusion cardiovascular magnetic resonance (CMR). Participants with silent coronary disease were excluded. Multivariable linear regression was performed to identify determinants of MPR with an interaction term for sex.

Results: Four hundred and seventy-nine T2D (age 57 ± 11 years, 42% [202/479] women) were compared with 116 controls (age 53 ± 11 years, 41% [48/116] women). Men with T2D, but not women, demonstrated worse systolic function and higher extracellular volume fraction than controls. MPR was significantly lower in T2D than controls (women, 2.6 ± 0.9 vs 3.3 ± 1.0, p < 0.001; men, 3.1 ± 0.9 vs 3.5 ± 1.0, p = 0.004), and lower in women than men with T2D (p < 0.001). More women than men with T2D had MPR <2.5 (46% [79/202] vs 26% [64/277], p < 0.001). There was a significant interaction between sex and body mass index (BMI) for MPR (p interaction <0.001). Following adjustment for clinical risk factors, inverse association with MPR were BMI in women (β = -0.17, p = 0.045) and systolic blood pressure in men (β = -0.14, p = 0.049).

Conclusion: Among asymptomatic adults with T2D, women had a greater prevalence of CMD than men. Risk factors modestly but significantly associated with CMD in asymptomatic people with T2D were BMI among women and systolic blood pressure among men.

Background: Pulmonary hypertension (PH) is a heterogeneous condition and regardless of etiology impacts negatively on survival. Diagnosis of PH is based on hemodynamic parameters measured invasively at right heart catheterization (RHC); however, a non-invasive alternative would be clinically valuable. Our aim was to estimate RHC parameters non-invasively from cardiac magnetic resonance (MR) data using deep learning models and to identify key contributing imaging features.

Methods: We constructed an explainable convolutional neural network (CNN) taking cardiac MR cine series from four different views as input to predict mean pulmonary artery pressure (mPAP). The model was trained and evaluated on 1646 examinations. The model's attention weight and predictive performance associated with each frame, view, or phase were used to judge its importance. Additionally, the importance of each cardiac chamber was inferred by perturbing part of the input pixels.

Results: The model achieved a Pearson correlation coefficient of 0.80 and R² of 0.64 in predicting mPAP and identified the right ventricle region on short-axis view to be especially informative.

Conclusion: Hemodynamic parameters can be estimated non-invasively with a CNN, using MR cine series from four views, revealing key contributing features at the same time.

Background: Contemporary 0.55T magnetic resonance imaging (MRI) is promising for fetal MRI, due to the larger bore, reduced safety concerns, lower acoustic noise, and improved fast imaging capability. In this work, we explore improved fetal cardiovascular magnetic resonance (CMR) without relying on any synchronizing devices, prospective, or retrospective gating, to determine the feasibility of real-time MRI evaluation of fetal cardiac function as well as cardiac and great vessel anatomies by using spiral balanced steady-state free precession (bSSFP) at 0.55T.

Methods: A real-time spiral bSSFP pulse sequence for fetal CMR was implemented and optimized on a 0.55T whole-body MRI. Fetal CMR was prospectively performed between May 2022 and August 2023. The protocol included (1) real-time images at standard cardiac views, for 10-20 s/view and 40-43.6 ms/frame and (2) 4-9 stacks of slices at standard cardiac views that each cover the whole heart, with 15-30 slices/stack, and 2-5 s/slice, at 320-349 ms/frame. Images were evaluated by a fetal cardiologist. Quantitative measurements of cardiothoracic area ratio and cardiac axis were compared with previous reports. Diagnostic accuracy was compared against postnatal echocardiographic findings.

Results: Twenty-nine participants were enrolled for 32 CMR exams, with mean maternal age 33.6 ± 5.8 years (range 22-44 years) and mean gestational age 32.8 ± 3.9 weeks (range 23-38 weeks). The proposed sequence enabled evaluation of the fetal heart in <30 min in all cases (average 22 min). Real-time MRI allowed easy adjustment of scan plan, automatic whole-heart volumetric sweeping, and flexible choice of reconstruction temporal resolution. For key cardiac anatomic features, 60% (315/527) were delineated well. Mean cardiothoracic area ratio and cardiac axis were 0.27 ± 0.04 and 45.8 ± 7.8 degrees. Diagnostic agreement with postnatal echocardiographic findings was 84% (26/31).

Conclusion: A spiral real-time bSSFP pulse sequence at 0.55T can provide both low-framerate and high-framerate fetal heart images without relying on maternal breath-hold, specialized gating devices, or cardiac gating. The low-framerate images offer high diagnostic quality structural evaluations of the fetal heart, while the high-framerate images capture fetal heart motion and may enable functional assessments.

Background: Cardiovascular magnetic resonance (CMR) is an important imaging modality for the assessment of heart disease; however, limitations of CMR include long exam times and high complexity compared to other cardiac imaging modalities. Recently advancements in artificial intelligence (AI) technology have shown great potential to address many CMR limitations. While the developments are remarkable, translation of AI-based methods into real-world CMR clinical practice remains at a nascent stage and much work lies ahead to realize the full potential of AI for CMR.

Methods: Herein we review recent cutting-edge and representative examples demonstrating how AI can advance CMR in areas such as exam planning, accelerated image reconstruction, post-processing, quality control, classification and diagnosis.

Results: These advances can be applied to speed up and simplify essentially every application including cine, strain, late gadolinium enhancement, parametric mapping, 3D whole heart, flow, perfusion and others. AI is a unique technology based on training models using data. Beyond reviewing the literature, this paper discusses important AI-specific issues in the context of CMR, including (1) properties and characteristics of datasets for training and validation, (2) previously published guidelines for reporting CMR AI research, (3) considerations around clinical deployment, (4) responsibilities of clinicians and the need for multi-disciplinary teams in the development and deployment of AI in CMR, (5) industry considerations, and (6) regulatory perspectives.

Conclusions: Understanding and consideration of all these factors will contribute to the effective and ethical deployment of AI to improve clinical CMR.