Cardiovascular magnetic resonance imaging to assess myocardial fibrosis in valvular heart disease

Recent updates on asymptomatic and symptomatic aortic valve stenosis its diagnosis, pathogenesis, management and future perspectives

Aortic stenosis (AS) is very common in mid-aged and elderly patients, and it has been reported to have a negative impact on both short and long-term survival with a high mortality rate. The current study identified methods of diagnosis, incidence, and causes of AS, pathogenesis, intervention and management and future perspectives of Asymptomatic and Symptomatic Aortic stenosis. A systematic literature search was conducted using PubMed, Scopus and CINAHL, using the Mesh terms and key words "Aortic stenosis", "diagnostic criteria", "pathogenesis", "incidence and causes of AS" and" intervention and management strategies". Studies were retained for review after meeting strict inclusion criteria that included studies evaluating Asymptomatic and Symptomatic AS. Studies were excluded if duplicate publication, overlap of patients, subgroup studies of a main study, lack of data on AS severity, case reports and letters to editors. Forty-five articles were selected for inclusion. Incidence of AS across the studies ranged from 3 % to 7 %. Many factors have been associated with incidence and increased risk of AS, highest incidence of AS was described after aortic valve calcification, rheumatic heart disease, degenerative aortic valve disease, bicuspid aortic valve and other factors. AS is common and can be predicted by aortic root calcification volume, rheumatic heart disease, degenerative aortic valve disease, bicuspid aortic valve. Intervention and management for AS patients is a complex decision that takes into consideration multiple factors. On the other hand, there is not enough progress in preventive pharmacotherapy to slow the progression of AS.

Left Ventricular Fibrosis by Cardiac Magnetic Resonance Tissue Characterization in Chronic Mitral Regurgitation Patients

Background: Left ventricular remodeling in chronic mitral regurgitation (MR) encompasses two types of myocardial fibrosis: replacement fibrosis, identified by late gadolinium enhancement (LGE), and diffuse interstitial fibrosis, assessed by pre- and postcontrast T1 mapping techniques. These may explain irreversible LV dysfunction after MR correction. We aimed to assess the presence of myocardial fibrosis in patients with moderate and severe MR with no criteria for surgery versus mild MR controls. Methods: We enrolled 137 patients with chronic primary MR and 130 controls; all underwent cardiac magnetic resonance, and were followed up in a median of 2.9 years to assess mortality and the need for mitral valve replacement. Results: Patients in the study group displayed significantly higher degrees of LGE (28.4% vs 7.69%, p < 0.05), higher native T1 values (1167 ± 58.5 versus 971 ± 51.4 (p < 0.05)), and higher extracellular volumes compared to controls (32.3% ± 3.5 versus 23.9 ± 2.2, (p < 0.05)). The composite outcome occurred in 28 patients in the study group (20.4%), and significantly higher with LGE+ (78.5%). Replacement fibrosis (HR = 1.83, 95% CI, p < 0.01) and interstitial fibrosis (HR = 1.61, 95% CI, p < 0.01) were independent predictors for the composite outcome. Conclusions: Patients with moderate and severe MR with no criteria for surgery still exhibit a significant degree of both replacement and interstitial fibrosis, with prognostic implications.

Imaging at the nexus: how state of the art imaging techniques can enhance our understanding of cancer and fibrosis

Both cancer and fibrosis are diseases involving dysregulation of cell signaling pathways resulting in an altered cellular microenvironment which ultimately leads to progression of the condition. The two disease entities share common molecular pathophysiology and recent research has illuminated the how each promotes the other. Multiple imaging techniques have been developed to aid in the early and accurate diagnosis of each disease, and given the commonalities between the pathophysiology of the conditions, advances in imaging one disease have opened new avenues to study the other. Here, we detail the most up-to-date advances in imaging techniques for each disease and how they have crossed over to improve detection and monitoring of the other. We explore techniques in positron emission tomography (PET), magnetic resonance imaging (MRI), second generation harmonic Imaging (SGHI), ultrasound (US), radiomics, and artificial intelligence (AI). A new diagnostic imaging tool in PET/computed tomography (CT) is the use of radiolabeled fibroblast activation protein inhibitor (FAPI). SGHI uses high-frequency sound waves to penetrate deeper into the tissue, providing a more detailed view of the tumor microenvironment. Artificial intelligence with the aid of advanced deep learning (DL) algorithms has been highly effective in training computer systems to diagnose and classify neoplastic lesions in multiple organs. Ultimately, advancing imaging techniques in cancer and fibrosis can lead to significantly more timely and accurate diagnoses of both diseases resulting in better patient outcomes.

Primary mitral regurgitation: Toward a better quantification on left ventricular consequences

BACKGROUND

Left ventricular end-systolic diameter (LVESD) and ejection fraction (LVEF) are the parameters to look for when discussing repair in asymptomatic patients with a primary mitral regurgitation (PMR). Loading conditions are altering LV-function quantification. LV-myocardial work (LVMW) is a method based on pressure-strain loops.

HYPOTHESIS

We sought to evaluate the additive value of the LVMW for predicting clinical events in patients with PMR.

METHODS

103 patients (66% men, median age 57 years) with asymptomatic severe PMR were explored at rest and during an exercise stress echocardiography. LV myocardial global work index (GWI), constructive work (GCW), wasted work (GWW), and work efficiency (GWE) were measured with speckle-tracking echocardiography at rest and low workload. The indication for surgery was based on the heart teams' decision. The median follow-up was 670 days.

RESULTS

Clinical events occurred for 50 patients (48.5%) with a median of event-free survival distribution of 289 days. Systolic pulmonary artery pressure (sPAP) at rest was 32.61 ± 8.56 mmHg and did not predict the risk of event like LVEF and LVESD. Changes in, GLS (hazard ratio [HR] 0.55; 95% confidence interval (Cl): 0.36-0.83; p = .005), GWI (HR 1.01; 95% Cl: 1.00-1.02; p = .002) and GCW (HR 1.85; 95% Cl: 1.28-2.68; p = .001) in addition to Left Atrial Volume Index (HR 1.73; 95% CI: 1.28 - 2.33; p < 0,001) were independent predictors of events.

CONCLUSION

Changes in myocardial work indices related to low-dose exercise are relevant to best predict PMR patient prognosis It might help to better select patient's candidate for "early-surgery."

CMR Mapping: The 4th-Era Revolution in Cardiac Imaging

Cardiac magnetic resonance (CMR) imaging has witnessed substantial progress with the advent of parametric mapping techniques, most notably T1 and T2 mapping. These advanced techniques provide valuable insights into a wide range of cardiac conditions, including ischemic heart disease, cardiomyopathies, inflammatory cardiomyopathies, heart valve disease, and athlete's heart. Mapping could be the first sign of myocardial injury and oftentimes precedes symptoms, changes in ejection fraction, and irreversible myocardial remodeling. The ability of parametric mapping to offer a quantitative assessment of myocardial tissue properties addresses the limitations of conventional CMR methods, which often rely on qualitative or semiquantitative data. However, challenges persist, especially in terms of standardization and reference value establishment, hindering the wider clinical adoption of parametric mapping. Future developments should prioritize the standardization of techniques to enhance their clinical applicability, ultimately optimizing patient care pathways and outcomes. In this review, we endeavor to provide insights into the potential contributions of CMR mapping techniques in enhancing the diagnostic processes across a range of cardiac conditions.

Assessment of the Severity of Aortic Regurgitation by Noninvasive Imaging : Non-invasive MMI for AR

PURPOSE OF THE REVIEW

The role of multimodality imaging in the evaluation of patients with aortic regurgitation is summarized in this review.

RECENT FINDINGS

The etiology (mechanism) of the aortic regurgitation and the severity of aortic regurgitation and hemodynamic consequences are key in the decision making of patients with severe aortic regurgitation. While echocardiography remains as the leading technique to assess all these parameters, other imaging techniques have become essential for the accurate assessment of aortic regurgitation severity and the timing of aortic intervention. The anatomic suitability of transcatheter aortic valve implantation in inoperable patients with severe aortic regurgitation is usually assessed with computed tomography. Aortic regurgitation is a prevalent disease with various pathophysiological mechanisms that need a personalized treatment. The evaluation of the mechanism and severity of aortic regurgitation can be initially performed with echocardiography. Three-dimensional techniques, including echocardiography, have become very relevant for accurate assessment of the regurgitation severity and its hemodynamic consequences. Assessment of myocardial tissue characteristics with cardiac magnetic resonance is key in the risk stratification of patients and in the timing of aortic intervention. Computed tomography is important in the assessment of aortic dimensions and selection of patients for transcatheter aortic valve implantation.

Prognostic Value of Cardiac Magnetic Resonance Imaging in Chronic Aortic Regurgitation: A Systematic Review and Meta-Analysis

Background

Chronic aortic regurgitation (AR) is a common valvular disease characterized by an overload of left ventricular volume and pressure. Accurate assessment of the heart from all angles is crucial for effective clinical management and prognostic evaluation of AR patients. As an advanced imaging technique, cardiac magnetic resonance (CMR) has become the gold standard for assessing cardiac volume and function. Accordingly, this study aimed to evaluate the prognostic value of CMR in chronic AR.

Methods

EMBASE, Cochrane Library, PubMed, and Web of Science were searched for clinical studies published between inception and July 19, 2022. Only studies that used CMR to assess patients with chronic isolated AR and provided prognostic data were included.

Results

For our analysis, 11 studies, which involved 1702 subjects and follow-up periods of 0.6-9.7 years, were eligible. We identified 13 CMR-related parameters associated with AR prognosis. With aortic valve surgery as the outcome, we estimated the pooled hazard ratios (HRs) for four of these parameters: aortic regurgitation fraction (ARF), aortic regurgitation volume (ARV), left ventricle end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV). The pooled HR for ARF was found to be 4.31 (95% confidence interval [CI]: 1.12-16.59, p = 0.034), while that for ARV was 3.88 (95% CI: 0.71-21.04, p = 0.116). Additionally, the combined HRs of LVEDV and LVESV were estimated to be 2.20 (95% CI: 1.04-4.67, p = 0.039) and 3.14 (95% CI: 1.22-8.07, p = 0.018), respectively.

Conclusions

The assessment of ARF, LVEDV, and LVESV via CMR has significant prognostic value in predicting the prognosis of AR patients with aortic valve surgery as an endpoint. It is recommended to consider using multi-parameter CMR in the clinical management of AR patients for timely interventions and effective prognostic evaluation.

Left ventricular myocardial work for the prediction of postoperative outcomes in patients with bicuspid aortic stenosis

Chronic elevation of left ventricular (LV) afterload contributes to adverse LV remodeling and myocardial impairment in bicuspid aortic valve (BAV) patients with severe aortic stenosis (AS). Incorporating LV afterload into global longitudinal strain (GLS) analysis, myocardial work facilitates early detection of LV dysfunction. The present study was to evaluate myocardial work in BAV patients with severe AS undergoing surgical aortic valve replacement (SAVR) and to evaluate its prognostic impact on early postoperative outcomes. Between January 2021 and March 2022, BAV patients with severe AS scheduled for SAVR were included and underwent comprehensive transthoracic echocardiography. Quantification of LV myocardial work was performed to obtain LV global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). Clinical outcome was defined as a composite of major cardiovascular events including mortality, myocardial infarction, stroke, acute kidney injury, low cardiac output syndrome and vascular complications during hospitalization or within 30 days after operation. Among 103 BAV patients with severe AS undergoing SAVR (mean age of 65 ± 9 years, 57.3% male), 22 experienced postoperative major cardiovascular events. BAV patients with major cardiovascular events demonstrated lower LV GWI (P < 0.001) and GCW (P = 0.002) along with elder age (P = 0.030), decreased LVGLS (P = 0.026) and right ventricular longitudinal strain (P = 0.019), and higher prevalence of abnormal average E/e' ratio (P = 0.029) than those without major events. Decreased LV GWI and GCW was independently associated with the occurrence of major cardiovascular events (P < 0.01 for adjusted OR). Multivariable logistic regression model including LV GWI demonstrated superior power than the model including LVGLS and yielded best discrimination for BAV patients with and without major cardiovascular events during early postoperative period. Echocardiography-based LV myocardial work overcomes the limitations of LVGLS and presents as a promising novel index for the early detection of functional myocardial damage and the optimization of intervention timing among BAV patients with severe AS.

High-sensitivity cardiac troponin T in infants exposed to anti-Ro antibodies

OBJECTIVES

Cardiac involvement in neonatal lupus erythematosis (NLE) can present as myocarditis/endocardial fibroelastosis (EFE). It is unknown whether high-sensitivity cardiac troponin T (hs-cTnT) is useful in identifying subclinical myocardial inflammation in infants exposed prenatally to anti-Ro antibodies. This study reports hs-cTnT levels in infants exposed to anti-Ro antibodies with/without cardiac NLE and reports cardiac MRI (CMR) findings in a subset of these children.

METHODS

The study included 45 consecutive infants exposed prenatally to anti-Ro antibodies with (n = 7) or without (n = 38) cardiac NLE, who were seen at the SickKids NLE Clinic between 2012 and 2014. Hs-cTnT levels were measured at least once, and those infants with values of ≥30 ng/l were offered the opportunity to undergo CMR. Descriptive statistics were performed.

RESULTS

Of 38 infants without cardiac NLE, 25 had a hs-cTnT level of ≥30 ng/l (including 1 of >113 ng/l); of these, 8 underwent CMR (all without myocarditis/EFE). All 7 infants with cardiac NLE had at least one hs-cTnT level of ≥30 ng/l, but only 2/7 had a level of >113 ng/l; 4/7 infants with cardiac NLE had CMR (all without myocarditis/EFE); 6/7 infants with cardiac NLE had their steroid treatment adjusted based on the trend in their hs-cTnT levels.

CONCLUSION

Only 3/45 anti-Ro antibodies-exposed infants had hs-cTnT values outside the reference range reported in healthy infants. None of 12 infants who had CMR had subclinical myocarditis/EFE. Routine measurement of hs-cTnT in every anti-Ro antibody-exposed infant is not indicated. Further studies are needed to define the role of hs-cTnT as a biomarker for cardiac NLE.

Latest Updates in Heart Failure Imaging

Heart failure (HF), a challenging and heterogeneous syndrome, still remains a major health problem worldwide, despite all the advances in prevention, diagnosis, and treatment of cardiovascular disease. Cardiac imaging plays a pivotal role in the classification of HF, accurate diagnosis of underlying etiology and decision-making. Integration of other imaging techniques such as cardiac magnetic resonance, nuclear imaging, and exercise imaging testing is important to characterize HF accurately. This article reviews the role of multimodality imaging to diagnose patients with HF.

Speckle-Tracking Echocardiography Predicts Adverse Left Ventricular Remodeling After Valve Replacement in Rheumatic Mitral Stenosis

Background

Rheumatic mitral stenosis(RMS) may leads to left ventricular remodeling (LVR), which can persist even after valve surgery. Identifying markers for early structure and function in patients with rheumatic heart disease who are at risk for adverse LVR after surgery can help determine the optimal timing of intervention. This study aimed to investigate whether preoperative parameters of global left ventricular long-axis strain (LVGLS) and mechanical discretization (MD) could predict postoperative adverse LVR.

Methods

A total of 109 adult patients with RMS and 50 healthy controls were enrolled in this study. Baseline clinical features, conventional echocardiography results, LVGLS, and MD were compared between the two groups. Pre- and post-surgery echocardiography measurements were collected, and adverse LVR was defined as a>15% increase in left ventricular end-diastolic volume or >10% decrease in left ventricular ejection fraction. Binary regression analysis was used to determine independent predictors of poor left ventricular remodeling.

Results

The variables associated with adverse LVR in this study were LVGLS (P<0.001, odds ratio: 1.996, 95% CI: 1.394-2.856) and MD (P=0.011, odds ratio: 1.031, 95% CI: 1.007-1.055). The poorly reconstructed group had lower absolute values of LVGLS and higher MD than the healthy control group and the non-poorly reconstructed group. A LVGLS cutoff of -15.0% was the best predictor for patients with poorly reconstructed LVR (sensitivity: 75.7%; specificity: 100.0%; AUC: 0.93), and a MD cutoff of 63.8ms was the best predictor (sensitivity: 63.8%; specificity: 98.6%; AUC: 0.88).

Conclusion

Speckle tracking echocardiography has potential value for predicting the progression of adverse LVR and for identifying non-responders among patients with RMS undergoing surgery.

Myocardial fibrosis in rheumatic heart disease: emerging concepts and clinical implications

Rheumatic heart disease (RHD) remains a significant cardiovascular burden in the world even though it is no longer common in affluent countries. Centuries of history surrounding this disease provide us with a thorough understanding of its pathophysiology. Infections in the throat, skin, or mucosa are the gateway for Group A Streptococcus (GAS) to penetrate our immune system. A significant inflammatory response to the heart is caused by an immunologic cascade triggered by GAS antigen cross-reactivity. This exaggerated immune response is primarily responsible for cardiac dysfunction. Recurrent inflammatory processes damage all layers of the heart, including the endocardium, myocardium, and pericardium. A vicious immunological cycle involving inflammatory mediators, angiotensin II, and TGF-β promotes extracellular matrix remodeling, resulting in myocardial fibrosis. Myocardial fibrosis appears to be a prevalent occurrence in patients with RHD. The presence of myocardial fibrosis, which causes left ventricular dysfunction in RHD, might be utilized to determine options for treatment and might also be used to predict the outcome of interventions in patients with RHD. This emerging concept of myocardial fibrosis needs to be explored comprehensively in order to be optimally utilized in the treatment of RHD.

Molecular Imaging of Myocardial Fibroblast Activation in Patients with Advanced Aortic Stenosis Before Transcatheter Aortic Valve Replacement: A Pilot Study

Using multimodal imaging, we investigated the extent and functional correlates of myocardial fibroblast activation in patients with aortic stenosis (AS) scheduled for transcatheter aortic valve replacement (TAVR). AS may cause myocardial fibrosis, which is associated with disease progression and may limit response to TAVR. Novel radiopharmaceuticals identify upregulation of fibroblast activation protein (FAP) as a cellular substrate of cardiac profibrotic activity. Methods: Twenty-three AS patients underwent ⁶⁸Ga-FAP inhibitor 46 (⁶⁸Ga-FAPI) PET, cardiac MRI, and echocardiography within 1-3 d before TAVR. Imaging parameters were correlated and then were integrated with clinical and blood biomarkers. Control cohorts of subjects without a history of cardiac disease and with (n = 5) and without (n = 9) arterial hypertension were compared with matched AS subgroups. Results: Myocardial FAP volume varied significantly among AS subjects (range, 1.54-138 cm³, mean ± SD, 42.2 ± 35.6 cm³) and was significantly higher than in controls with (7.42 ± 8.56 cm³, P = 0.007) and without (2.90 ± 6.67 cm³; P < 0.001) hypertension. FAP volume correlated with N-terminal prohormone of brain natriuretic peptide (r = 0.58, P = 0.005), left ventricular ejection fraction (r = -0.58, P = 0.02), mass (r = 0.47, P = 0.03), and global longitudinal strain (r = 0.55, P = 0.01) but not with cardiac MRI T1 (spin-lattice relaxation time) and extracellular volume (P = not statistically significant). In-hospital improvement in left ventricular ejection fraction after TAVR correlated with pre-TAVR FAP volume (r = 0.440, P = 0.035), N-terminal prohormone of brain natriuretic peptide, and strain but not with other imaging parameters. Conclusion: FAP-targeted PET identifies varying degrees of left ventricular fibroblast activation in TAVR candidates with advanced AS. ⁶⁸Ga-FAPI signal does not match other imaging parameters, generating the hypothesis that it may become useful as a tool for personalized selection of optimal TAVR candidates.

CARdioimaging in Lung Cancer PatiEnts Undergoing Radical RadioTherapy: CARE-RT Trial

BACKGROUND

Non-small-cell lung cancer (NSCLC) is a common, steady growing lung tumour that is often discovered when a surgical approach is forbidden. For locally advanced inoperable NSCLC, the clinical approach consists of a combination of chemotherapy and radiotherapy, eventually followed by adjuvant immunotherapy, a treatment that is useful but may cause several mild and severe adverse effect. Chest radiotherapy, specifically, may affect the heart and coronary artery, impairing heart function and causing pathologic changes in myocardial tissues. The aim of this study is to evaluate the damage coming from these therapies with the aid of cardiac imaging.

METHODS

This is a single-centre, prospective clinical trial. Patients with NSCLC who are enrolled will undergo computed tomography (CT) and magnetic resonance imaging (MRI) before chemotherapy 3 months, 6 months, and 9-12 months after the treatment. We expect to enrol 30 patients in 2 years.

CONCLUSIONS

Our clinical trial will be an opportunity not only to highlight the timing and the radiation dose needed for pathological cardiac tissue changes to happen but will also provide useful data to set new follow-up schedules and strategies, keeping in mind that, more often than not, patients affected by NSCLC may present other heart- and lung-related pathological conditions.

Valvular heart disease: shifting the focus to the myocardium

Adverse cardiac remodelling is the main determinant of patient prognosis in degenerative valvular heart disease (VHD). However, to give an indication for valvular intervention, current guidelines include parameters of cardiac chamber dilatation or function which are subject to variability, do not directly reflect myocardial structural changes, and, more importantly, seem to be not sensitive enough in depicting early signs of myocardial dysfunction before irreversible myocardial damage has occurred. To avoid irreversible myocardial dysfunction, novel biomarkers are advocated to help refining indications for intervention and risk stratification. Advanced echocardiographic modalities, including strain analysis, and magnetic resonance imaging have shown to be promising in providing new tools to depict the important switch from adaptive to maladaptive myocardial changes in response to severe VHD. This review, therefore, summarizes the current available evidence on the role of these new imaging biomarkers in degenerative VHD, aiming at shifting the clinical perspective from a valve-centred to a myocardium-focused approach for patient management and therapeutic decision-making.

Radiotherapy-Induced Cardiotoxicity: The Role of Multimodality Cardiovascular Imaging

Radiotherapy (RT) is one of the pillars of cancer therapy. High-dose radiation exposure on the thorax is mainly used in the context of adjuvant RT after breast surgery, in lung and esophageal cancer, and as a complement to systemic treatment in lymphoma. Due to the anatomical proximity, the heart inevitably receives some radiation that can result in acute and chronic cardiotoxicity, leading to heart failure, coronary artery disease, pericardial and valvular heart disease. Current evidence suggests there is no safe radiation dose to the heart, which poses a need for early recognition of RT-induced cardiac injury to initiate cardioprotective treatment and prevent further damage. Multimodality cardiac imaging provides a powerful tool to screen for structural and functional abnormalities secondary to RT. Left ventricular ejection fraction, preferably with three-dimensional echocardiography or cardiovascular magnetic resonance (CMR), and global longitudinal strain with speckle-tracking echocardiography are currently the key parameters to detect cardiotoxicity. However, several novel imaging parameters are tested in the ongoing clinical trials. CMR parametric imaging holds much promise as T1, T2 mapping and extracellular volume quantification allow us to monitor edema, inflammation and fibrosis, which are fundamental processes in RT-induced cardiotoxicity. Moreover, the association between serum biomarkers, genetic polymorphisms and the risk of developing cardiovascular disease after chest RT has been demonstrated, providing a platform for an integrative screening approach for cardiotoxicity. The present review summarizes contemporary evidence of RT-induced cardiac injury obtained from multimodality imaging—echocardiography, cardiovascular computed tomography, CMR and nuclear cardiology. Moreover, it identifies gaps in our current knowledge and highlights future perspectives to screen for RT-induced cardiotoxicity.

Functional and structural reverse myocardial remodeling following transcatheter aortic valve replacement: a prospective cardiovascular magnetic resonance study

BACKGROUND

Since cardiovascular magnetic resonance (CMR) imaging allows comprehensive quantification of both myocardial function and structure we aimed to assess myocardial remodeling processes in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR).

METHODS

CMR imaging was performed in 40 patients with severe AS before and 1 year after TAVR. Image analyses comprised assessments of myocardial volumes, CMR-feature-tracking based atrial and ventricular strain, myocardial T1 mapping, extracellular volume fraction-based calculation of left ventricular (LV) cellular and matrix volumes, as well as ischemic and non-ischemic late gadolinium enhancement analyses. Moreover, biomarkers including NT-proBNP as well as functional and clinical status were documented.

RESULTS

Myocardial function improved 1 year after TAVR: LV ejection fraction (57.9 ± 16.9% to 65.4 ± 14.5%, p = 0.002); LV global longitudinal (- 21.4 ± 8.0% to -25.0 ± 6.4%, p < 0.001) and circumferential strain (- 36.9 ± 14.3% to - 42.6 ± 11.8%, p = 0.001); left atrial reservoir (13.3 ± 6.3% to 17.8 ± 6.7%, p = 0.001), conduit (5.5 ± 3.2% to 8.4 ± 4.6%, p = 0.001) and boosterpump strain (8.2 ± 4.6% to 9.9 ± 4.2%, p = 0.027). This was paralleled by regression of total myocardial volume (90.3 ± 21.0 ml/m2 to 73.5 ± 17.0 ml/m2, p < 0.001) including cellular (55.2 ± 13.2 ml/m2 to 45.3 ± 11.1 ml/m2, p < 0.001) and matrix volumes (20.7 ± 6.1 ml/m2 to 18.8 ± 5.3 ml/m2, p = 0.036). These changes were paralleled by recovery from heart failure (decrease of NYHA class: p < 0.001; declining NT-proBNP levels: 2456 ± 3002 ng/L to 988 ± 1222 ng/L, p = 0.001).

CONCLUSION

CMR imaging enables comprehensive detection of myocardial remodeling in patients undergoing TAVR. Regression of LV matrix volume as a surrogate for reversible diffuse myocardial fibrosis is accompanied by increase of myocardial function and recovery from heart failure. Further data are required to define the value of these parameters as therapeutic targets for optimized management of TAVR patients. Trial registration DRKS, DRKS00024479. Registered 10 December 2021-Retrospectively registered, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00024479.

The Role of Cardiac Magnetic Resonance in Aortic Stenosis and Regurgitation

Cardiac magnetic resonance (CMR) imaging is a well-set diagnostic technique for assessment of valvular heart diseases and is gaining ground in current clinical practice. It provides high-quality images without the administration of ionizing radiation and occasionally without the need of contrast agents. It offers the unique possibility of a comprehensive stand-alone assessment of the heart including biventricular function, left ventricle remodeling, myocardial fibrosis, and associated valvulopathies. CMR is the recognized reference for the quantification of ventricular volumes, mass, and function. A particular strength is the ability to quantify flow, especially with new techniques which allow accurate measurement of stenosis and regurgitation. Furthermore, tissue mapping enables the visualization and quantification of structural changes in the myocardium. In this way, CMR has the potential to yield important prognostic information predicting those patients who will progress to surgery and impact outcomes. In this review, the fundamentals of CMR in assessment of aortic valve diseases (AVD) are described, together with its strengths and weaknesses. This state-of-the-art review provides an updated overview of CMR potentials in all AVD issues, including valve anatomy, flow quantification, ventricular volumes and function, and tissue characterization.

Mitral Annular Disjunction: Pathophysiology, Pro-Arrhythmic Profile and Repair Pearls

Mitral annular disjunction (MAD) is a structural abnormality defined by a distinct separation of the mitral valve annulus-left atrial wall continuum and the basal aspect of the posterolateral left ventricle. This anomaly is often observed in patients with myxomatous mitral valve prolapse. Importantly, MAD has been strongly associated with serious ventricular arrhythmias and predisposes to sudden cardiac death. Therefore, we have to emphasize the need to diagnose this morphologic and functional abnormality in routine practice in order to facilitate optimal mitral valve repair and minimize patient risks. Nevertheless, clinical knowledge regarding MAD still remains limited. In the present review, we aim to shed light on several aspects of MAD, including distinct anatomical and pathophysiological characteristics, imaging modalities, association with ventricular arrhythmias, and current methods of treatment.

Valvular Cardiomyopathy: The Value of Cardiovascular Magnetic Resonance Imaging

Cardiovascular magnetic resonance (CMR) imaging has had a vast impact on the understanding of a wide range of disease processes and pathophysiological mechanisms. More recently, it has contributed significantly to the diagnosis and risk stratification of patients with valvular heart disease. With its increasing use, CMR allows for a detailed, reproducible, qualitative, and quantitative evaluation of left ventricular volumes and mass, thereby enabling assessment of the haemodynamic impact of a valvular lesion upon the myocardium. Postprocessing of the routinely acquired images with feature tracking CMR methodology can give invaluable information about myocardial deformation and strain parameters that suggest subclinical ventricular impairment that remains undetected by conventional measures such as the ejection fraction (EF). T1 mapping and late gadolinium enhancement (LGE) imaging provide deep myocardial tissue characterisation that is changing the approach towards risk stratification of patients as an increasing body of evidence suggests that the presence of fibrosis is related to adverse events and prognosis. This review summarises the current evidence regarding the utility of CMR in the left ventricular assessment of patients with aortic stenosis or mitral regurgitation and its value in diagnosis, risk stratification, and management.

Long Term Prognostic Value of Contractile Reserve Assessed by Global Longitudinal Strain in Patients with Asymptomatic Severe Aortic Stenosis

Background. Left ventricle (LV) global longitudinal strain (GLS) at rest has shown prognostic value in patients (pts) with severe aortic stenosis (SAS). Contractile reserve (CR) during exercise stress echo (ESE) estimated via GLS (CR-GLS) could better stratify the asymptomatic patients who could benefit from early intervention. Aims. To determine the long-term prognostic value of CR-GLS in patients with asymptomatic SAS with an ESE without inducible ischemia. Additionally, to compare the prognostic value of CR assessed via ejection fraction (CR-EF) and CR-GLS. Methods. In a prospective, single-center, observational study between 2013 and 2019, 101 pts with asymptomatic SAS and preserved left ventricular ejection fraction (LVEF) > 55% were enrolled. CR was considered present with an exercise-rest increase in LVEF (Simpson’s rule) ≥ 5 points and > 2 absolute points in GLS. Patients were assigned to 2 groups (G): G1: 56 patients with CR-GLS present; and G2: 45 patients CR-GLS absent. All patients were followed up. Results. G2 Patients were older, with lower exercise capability, less aortic valve area (AVA), a higher peak aortic gradient, and less LVEF (71.5% ± 5.9 vs. 66.8% ± 7.9; p = 0.002) and GLS (%) at exercise (G1: −22.2 ± 2.8 vs. G2: −18.45 ± 2.4; p = 0.001). During mean follow-up of 46.6 ± 3.4 months, events occurred in 45 pts., with higher incidence in G2 (G2 = 57.8% vs. G1 = 42.2%, p < 0.01). At Cox regression analysis, CR-GLS was an independent predictor of major cardiovascular events (HR: 1.98, 95% CI 1.09–3.58, p = 0.025). Event-free survival was lower for patients with CR-GLS absent (log rank test p = 0.022). CR-EF was not outcome predictive (log rank test p 0.095). Conclusions: In patients with asymptomatic SAS, the absence of CR-GLS during ESE is associated with worse prognosis. Additionally, CR-GLS was a better predictor of events than CR-EF.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

BACKGROUND

 Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles.

METHOD

 The review is based on a PubMed literature search using the search terms "transcatheter heart valve", "TAVI", "TAVR", "CT", "imaging", "MR" over a period from 2010-2020, combined with personal comments based on the author's experience.

RESULTS AND CONCLUSION

 CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration.

KEY POINTS

  · CT plays a crucial role in evaluating transcatheter heart valve candidates. · Evaluation must include the dimensions of the aortic root and access paths. · The exact post-procedural role of CT and MRI has not yet been determined..

CITATION FORMAT

· Salgado R, El Addouli H, Budde RP. Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021. Fortschr Röntgenstr 2021; 193: 1411 - 1425.

Pregnancy related changes in Doppler gradients and left ventricular mechanics in women with sub-valvular or valvular aortic stenosis

BACKGROUND

The aim of our study was to characterize echocardiographic changes during pregnancy in women with known LVOT obstruction or AS compared to the healthy pregnancy controls, and to assess the relationship with pregnancy outcomes.

METHODS

We retrospectively studied 34 pregnant patients with congenital LVOT obstruction or AS with healthy age-matched pregnant controls. Patients with other significant valvular lesions, structural heart disease (LVEF < 40%), or prior valve surgery were excluded. All LVOTO/AS patients underwent a minimum of two consecutive echocardiograms between 1 year pre-conception and 1 year postpartum, with at least two studies during the pregnancy. Comprehensive echocardiographic evaluation was performed including speckle-tracking LV global longitudinal strain.

RESULTS

A total of 83 echocardiograms from the study group and 34 echocardiograms from the control group were evaluated. Over the range of LVOTO/AS, a significantly greater increase in the AV gradients and LV and LA volumes were observed as compared with the controls. In the sub-group of LVOTO/AS pregnant women with ≥ moderate (n = 8) versus < moderate LVOTO/AS (n = 26), averaged 2^nd /3^rd trimester LVEF was lower (51 ± 12)% versus (58 ± 4)%, (p = 0.02) and GLS was lower (-19.5 ± 2.8) versus (21.2 ± 2.4), (p = 0.06). Pregnancy was well tolerated despite these changes.

CONCLUSION

Among pregnant women with even milder forms of LVOTO/AS, increases in cardiac volumes and AV gradients can be expected over the course of pregnancy. Significant decreases in LV function and mechanics were only observed in women with moderate or greater LVOTO/AS, although still remained in normal range.

Myocardial Involvement in COVID-19: an Interaction Between Comorbidities and Heart Failure with Preserved Ejection Fraction. A Further Indication of the Role of Inflammation

PURPOSE OF THE REVIEW

Coronavirus Disease 2019 (COVID-19) and cardiovascular (CV) disease have a close relationship that emerged from the earliest reports. The aim of this review is to show the possible associations between COVID-19 and heart failure (HF) with preserved ejection fraction (HFpEF).

RECENT FINDINGS

In hospitalized patients with COVID-19, the prevalence of HFpEF is high, ranging from 4 to 16%, probably due to the shared cardio-metabolic risk profile. Indeed, comorbidities including hypertension, diabetes, obesity and chronic kidney disease - known predictors of a severe course of COVID-19 - are major causes of HFpEF, too. COVID-19 may represent a precipitating factor leading to acute decompensation of HF in patients with known HFpEF and in those with subclinical diastolic dysfunction, which becomes overt. COVID-19 may also directly or indirectly affect the heart. In otherwise healthy patients, echocardiographic studies showed that the majority of COVID-19 patients present diastolic (rather than systolic) impairment, pulmonary hypertension and right ventricular dysfunction. Such abnormalities are observed both in the acute or subacute phase of COVID-19. Cardiac magnetic resonance reveals myocardial inflammation and fibrosis in up to the 78% of patients in the chronic phase of the disease. These findings suggest that COVID-19 might be a novel independent risk factor for the development of HFpEF, through the activation of a systemic pro-inflammatory state. Follow-up studies are urgently needed to better understand long-term sequelae of COVID-19 inflammatory cardiomyopathy.

Collagen fiber regulation in human pediatric aortic valve development and disease

Congenital aortic valve stenosis (CAVS) affects up to 10% of the world population without medical therapies to treat the disease. New molecular targets are continually being sought that can halt CAVS progression. Collagen deregulation is a hallmark of CAVS yet remains mostly undefined. Here, histological studies were paired with high resolution accurate mass (HRAM) collagen-targeting proteomics to investigate collagen fiber production with collagen regulation associated with human AV development and pediatric end-stage CAVS (pCAVS). Histological studies identified collagen fiber realignment and unique regions of high-density collagen in pCAVS. Proteomic analysis reported specific collagen peptides are modified by hydroxylated prolines (HYP), a post-translational modification critical to stabilizing the collagen triple helix. Quantitative data analysis reported significant regulation of collagen HYP sites across patient categories. Non-collagen type ECM proteins identified (26 of the 44 total proteins) have direct interactions in collagen synthesis, regulation, or modification. Network analysis identified BAMBI (BMP and Activin Membrane Bound Inhibitor) as a potential upstream regulator of the collagen interactome. This is the first study to detail the collagen types and HYP modifications associated with human AV development and pCAVS. We anticipate that this study will inform new therapeutic avenues that inhibit valvular degradation in pCAVS and engineered options for valve replacement.

Non-contrast cardiovascular magnetic resonance detection of myocardial fibrosis in Duchenne muscular dystrophy

BACKGROUND

Duchenne muscular dystrophy (DMD) leads to progressive cardiomyopathy. Detection of myocardial fibrosis with late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) is critical for clinical management. Due to concerns of brain deposition of gadolinium, non-contrast methods for detecting and monitoring myocardial fibrosis would be beneficial.

OBJECTIVES

We hypothesized that native T1 mapping and/or circumferential (εcc) and longitudinal (εls) strain can detect myocardial fibrosis.

METHODS

156 CMRs with gadolinium were performed in 66 DMD boys and included: (1) left ventricular ejection fraction (LVEF), (2) LGE, (3) native T1 mapping and myocardial tagging (εcc-tag measured using harmonic phase analysis). LGE was graded as: (1) presence/absence by segment, slice, and globally; (2) global severity from 0 (no LGE) to 4 (severe); (3) percent LGE using full width half maximum (FWHM). εls and εcc measured using feature tracking. Regression models to predict LGE included native T1 and either εcc-tag or εls and εcc measured at each segment, slice, and globally.

RESULTS

Mean age and LVEF at first CMR were 14 years and 54%, respectively. Global εls and εcc strongly predicted presence or absence of LGE (OR 2.6 [1.1, 6.0], p = 0.029, and OR 2.3 [1.0, 5.1], p = 0.049, respectively) while global native T1 did not. Global εcc, εls, and native T1 predicted global severity score (OR 2.6 [1.4, 4.8], p = 0.002, OR 2.6 [1.4, 6.0], p = 0.002, and OR 1.8 [1.1, 3.1], p = 0.025, respectively). εls correlated with change in LGE by severity score (n = 33, 3.8 [1.0, 14.2], p = 0.048) and εcc-tag correlated with change in percent LGE by FWHM (n = 34, OR 0.2 [0.1, 0.9], p = 0.01).

CONCLUSIONS

Pre-contrast sequences predict presence and severity of LGE, with εls and εcc being more predictive in most models, but there was not an observable advantage over using LVEF as a predictor. Change in LGE was predicted by εls (global severity score) and εcc-tag (FWHM). While statistically significant, our results suggest these sequences are currently not a replacement for LGE and may only have utility in a very limited subset of DMD patients.

Prognostic significance of myocardial fibrosis and CMR characteristics in bicuspid aortic valve with moderate and severe aortic insufficiency

OBJECTIVES

This study attempted to evaluate the characteristics and prognostic value of myocardial fibrosis (MF) in aortic insufficiency (AI) patients with bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV) by cardiac magnetic resonance (CMR).

METHODS

A total of 314 adults with CMR-diagnosed AI were retrospectively retrieved. Of them, 166 patients with moderate or severe AI were included and divided into two groups: BAV group (N = 46) and a TAV group (N = 120). The presence and characteristics of MF were assessed with CMR. The patients were followed for adverse clinical events. The prognostic capability of the parameters was assessed using Cox regression model.

RESULTS

LV fibrosis was more common in the BAV group than in the TAV group (65.2% vs. 45.0%; p = 0.020). There was a strong association between BAV and MF even after adjusting for clinical and imaging variables (odds ratio: 3.57; p = 0.031). Kaplan-Meier analysis showed a higher rate of clinical adverse events in AI+BAV patients with MF during a median follow-up of 4.7 years. Multivariate Cox regression analysis showed that late gadolinium enhancement (LGE) was an independent predictor of clinical adverse outcome.

CONCLUSION

MF is more common in AI with BAV than with TAV and is a predictor of clinical adverse events.

KEY POINTS

• The presence and extent of late gadolinium enhancement of left ventricular were more common and severer in the bicuspid aortic valve group than in the tricuspid aortic valve group in aortic insufficiency patients. • Bicuspid aortic valve was an independent factor for myocardial fibrosis in aortic insufficiency patients. • Late gadolinium enhancement could be used as an independent predictor of adverse clinical events in this population.

Myocardial Fibrosis in Pediatric Patients With Ebstein's Anomaly

BACKGROUND

Left ventricular dysfunction in Ebstein's anomaly (EA) is associated with higher mortality. The health of the left ventricular myocardium in children and adolescents with EA has not been investigated in detail.

METHODS

Patients with unrepaired EA who had undergone cardiac magnetic resonance imaging including T1 mapping were retrospectively reviewed. Patients were compared with age- and sex-matched controls. EA severity index was calculated using volumetric measurements at end diastole ([right atrial+atrialized right ventricular volumes]/[functional right ventricular+left atrial+left ventricular volumes]). Global circumferential and radial strain and as well as strain rate were examined using cardiac magnetic resonance feature tracking.

RESULTS

Twelve EA patients and an equal number of controls were included. Functional and atrialized right ventricular end-diastolic volumes were 84±15 and 21±13 mL/m², respectively. Late gadolinium enhancement, confined to the right ventricle, was found in 2 patients (16%). Left ventricular native T1 values and extracellular volume fractions were higher in patients compared with controls (1026±47 versus 956±40 ms, P=0.0004 and 28.5±3.4% versus 22.5±2.6%, P<0.001, respectively). Native T1 times correlated inversely with patients' age, body surface area, and O₂ saturations (r=-0.63, -0.62, and -0.91, respectively; P=0.02, P=0.02, and P<0.0001, respectively). EA severity index ranged between 0.15 and 0.94 and correlated with T1 values (r=0.76, P=0.003). Native T1 correlated with global circumferential strain (r=0.58, P=0.04) but not ejection fraction (EF). EA patients had reduced maximum oxygen uptake (Vo₂max). Vo₂max correlated inversely with T1 values (r=-0.79, P=0.01).

CONCLUSIONS

Children and adolescents with EA experience an abnormal degree of diffuse myocardial fibrosis. Its association with O₂ saturation points toward a role of hypoxemia in the pathogenesis of fibrosis. Larger and prospective studies are needed to evaluate the value of T1 mapping for risk stratification and monitoring in EA.

Importance of Myocardial Fibrosis in Functional Mitral Regurgitation: From Outcomes to Decision-Making

Functional mitral regurgitation (FMR) is a common and complex valve disease, in which severity and risk stratification is still a conundrum. Although risk increases with FMR severity, it is modulated by subjacent left ventricular (LV) disease. The extent of LV remodeling and dysfunction is traditionally evaluated by echocardiography, but a growing body of evidence shows that myocardial fibrosis (MF) assessment by cardiac magnetic resonance (CMR) may complement risk stratification and inform treatment decisions. This review summarizes the current knowledge on the comprehensive evaluation that CMR can provide for patients with FMR, in particular for the assessment of MF and its potential impact in clinical decision-making.

Myxomatous Mitral Valve Disease with Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical and Functional Significance of the Coincidence

The morphological changes that occur in myxomatous mitral valve disease (MMVD) involve various components, ultimately leading to the impairment of mitral valve (MV) function. In this context, intrinsic mitral annular abnormalities are increasingly recognized, such as a mitral annular disjunction (MAD), a specific anatomical abnormality whereby there is a distinct separation between the mitral annulus and the left atrial wall and the basal portion of the posterolateral left ventricular myocardium. In recent years, several studies have suggested that MAD contributes to myxomatous degeneration of the mitral leaflets, and there is growing evidence that MAD is associated with ventricular arrhythmias and sudden cardiac death. In this review, the morphological characteristics of MAD and imaging tools for diagnosis will be described, and the clinical and functional aspects of the coincidence of MAD and myxomatous MVP will be discussed.

Predictors of moderate to severe ischemic mitral regurgitation after myocardial infarction: a cardiac magnetic resonance study

OBJECTIVES

The purpose of this study is to explore the predictors of moderate to severe ischemic mitral regurgitation (IMR) after myocardial infarction with cardiovascular magnetic resonance (CMR).

METHODS

From January 2016 to September 2018, 109 patients (mean age 60 ± 8 years) with IMR were studied retrospectively. All patients underwent CMR-cine with True-FISP sequence and late gadolinium enhancement (LGE) with a phase-sensitive inversion recovery sequence. The presence of papillary muscle infarction (PMI), global left ventricular (LV) infarcted extent, LV functional parameters, and LV myocardial strain were assessed. Univariate and multivariate analyses were performed to identify factors in the development of moderate to severe IMR.

RESULTS

Mild IMR was present in 61 patients (56%), and moderate to severe IMR was present in 48 patients (44%). PMI was identified in 22 patients (20.1%); 14 of them (63.63%) showed a moderate or severe IMR. Global LV infarcted extent was increased in patients with moderate to severe IMR (p < 0.001). LV functional parameters of patients with moderate to severe IMR were statistically different from those of the patients with mild IMR (all p < 0.001), except the LV SV index (p = 0.142) and LV CI (p = 0.447). The global longitudinal strain (GLS), regional radial strain (RS), and circumferential strain (CS) of the moderate-to-severe IMR group were significantly decreased compared with those of the mild IMR group (p < 0.05). In multivariable analyses, age (OR = 1.11; p = 0.001), global LV infarct extent (OR = 1.14; p = 0.000), and GLS (OR = 1.31; p = 0.000) were associated with moderate-to-severe chronic IMR.

CONCLUSIONS

The incidence of PMI was higher in patients with moderate-to-severe IMR. The extent of global LV infarcted extent and GLS were independent predictors of moderate-to-severe IMR.

KEY POINTS

• Cardiovascular magnetic resonance late gadolinium enhancement and feature-tracking imaging provide reliable information on LV function, myocardial viability, and papillary muscle morphology. • Papillary muscle infarction is not an independent predictor of moderate-to-severe IMR. • The extent of global LV infarction and LV global longitudinal strain were independent predictors of moderate-to-severe chronic IMR.

Strain patterns in primary mitral regurgitation due to rheumatic heart disease and mitral valve prolapse

OBJECTIVE

Left atrial (LA) and left ventricular (LV) remodelling are the adaptive changes that occur in primary mitral regurgitation (MR) and are related to its clinical outcomes. Despite the pathophysiological differences in MR in rheumatic heart disease (RHD) and mitral valve prolapse (MVP), whether the pattern of LV and LA remodelling is different between the two conditions remains unknown. Hence, we compared the LA and LV strain pattern in MR due to RHD, the predominant etiology in developing countries topatients with MVP and age and sex-matched controls.

METHODS

A total of 50 patients of severe MR which included 30 MVP MR and 20 RHD MR were assessed by strain imaging by speckle tracking echocardiography (STE) and were compared with age and sex-matched controls. 2D STE was used for LA and 3D STE was used for LV strain analysis. LA and LV strain parameters were compared between MVP MR and RHD MR groups.

RESULTS

30 patients with MVP and 20 with RHD were studied. 60% (n = 30) were symptomatic. Mean GLS was -17.2 ± 4.4% compared to -20 ± 3.2% among controls and mean LA strain was 17.35 ± 10.3% compared to 51.34 ± 11.5% among controls which were significantly lower (both p < 0.01). No significant difference in LA strain and GLS was found between MVP and RHD subgroups (LA strain 20.45 ± 11.9% and 14.63 ± 8.85%; p = 0.08; GLS - 18.25 ± 4.3% and-16.2 ± 4.6%; p = 0.12). PALS in the RHD group was lower compared to MVP(p = 0.08) which showed a trend towards significance. LV strain parameters showed no significant difference among the MVP and RHD groups.

CONCLUSION

LA and LV strain parameters showed no significant difference in MR due to either RHD or MVP. There was a trend towards lower LA strain in RHD which needs validation with large multicentric studies. The current strain parameters from MVP with the prognostic value may be applied to MR of RHD etiology, pending confirmation of our results by other groups.

Functional mitral regurgitation and cardiac resynchronization therapy in the "era" of trans-catheter interventions: Is it time to move from a staged strategy to a tailored therapy?

Cardiac resynchronization therapy (CRT) has been associated to left ventricle (LV) remodelling, reduction of functional mitral regurgitation (FMR) and clinical improvement in patients with heart failure and reduced ejection fraction (HFrEF). The prevalence of significant FMR in patients with LV dyssynchrony that are candidate to CRT is up to 40%. Current approach in patients with FMR undergoing CRT consists of re-evaluation of the amount of FMR following a waiting period of at least 3 months after the implant. In case of persistent significant FMR despite CRT and guideline directed medical therapy, trancatheter Mitral Valve repair (TMVR) is an important option to improve quality of life and prognosis. This stepwise approach does not take into account the probability of the individual response to CRT and the availability of TMVR solutions that are safe and effective in high risk patients. We reviewed the effects of CRT on FMR, the prognostic role of persistence of FMR after CRT treatment and the impact of treatment of FMR in patients CRT non responders. We aimed to point out the limits of current step-wised approach in light on more recent evidence regarding FMR treatment. A new, "tailored" approached is proposed.

Echocardiographic Analysis of Correlation Between Right Ventricle Load and Function and Left Ventricle Diastolic Malfunction in Symptomless Valvular Cardiovascular Disease Patients

Background

Left ventricle diastolic malfunction (LVDMf) is a valvular cardiovascular disease. Here, we assessed the correlation between right ventricle (RV) load and function (L&F) and diastolic malfunction (DMf) in symptomless valvular cardiovascular disease patients.

Material/Methods

We enrolled 59 subjects who underwent right-heart catheterization, assessing their echocardiographic analysis results while performing exercises in supine position, comparing results at rest and during maximum exercise. Subjects were furthermore stratified according to resting DMf. Using cardiac resonance imaging (CRM), we assessed cardiac morphology and chamber size. RV stroke, pulmonary artery conformation, pulmonary artery elastance, pulmonary artery pulsatility, and right atrial (pRA) pressure were indexed for supine exercises.

Results

We observed that DMf grade 1 (G-1) and grade 2 (G-2) were present in 28 patients and 16 patients, respectively, while the remaining 15 patients had a normal filling pattern in the left ventricle. In comparison to patients with DMf of G-1, patients with normal diastolic filling pattern had higher volume index for RV end-diastolic (endD) (81±14 mL/m²vs. 68±12 mL/m², P=0.08) and for RV end-systolic (endS) (34±11 mL/m²vs. 27±8 mL/m², P=0.07). We also observed that in G-2 DMf pulmonary artery, pressure and elastance of the pulmonary artery were enhanced and were correlated with optimum oxygen intake and RV volume (r=−0.69, P<0.001).

Conclusions

We found that enhancement in RV afterload, which returns to normal at rest, is correlated with mild DMf. Additionally, despite maximum exercise, it is reciprocally associated with maximum oxygen intake and right atrial pressure.

Clinical use of 4D flow MRI for quantification of aortic regurgitation

Objective

The main objective of the present study was to compare the use of four-dimensional (4D) flow MRI with the habitual sequence (two-dimensional phase-contrast (2DPC) MRI) for the assessment of aortic regurgitation (AR) in the clinical routine.

Methods

This was a retrospective, observational cohort study of patients with varying grades of AR. For the purposes of the present study, we selected all the cases with a regurgitant fraction (RF)>5% as determined by 2DPC MRI (n=34). In all cases, both sequences (2DPC and 4D flow MRI) were acquired in a single session to ensure comparability. We compared the results of the two techniques by evaluating forward flow, regurgitant flow and regurgitation fraction. Then, the patients were divided into subgroups to determine if these factors had any influence on the measurements: aortic diameter (≤ vs >38 mm), valve anatomy (tricuspid vs bicuspid/quadricuspid), stenosis (gradient ≥15 vs <15) and region of interest location (aortic valve vs sinotubular junction).

Results

No statistically significant differences were observed between the two techniques with Pearson’s correlation coefficients (r) of forward flow (r=0.826/p value<0001), regurgitant flow (r=0.866/p value<0001) and RF (r=0.761/p value<0001).

Conclusions

The findings of this study confirm the value of 4D flow MRI for grading AR in clinical practice with an excellent correlation with the standard technique (2DPC MRI).

Advanced cardiac MRI techniques for evaluation of left-sided valvular heart disease

The most common types of left‐sided valvular heart disease (VHD) in the Western world are aortic valve stenosis, aortic valve regurgitation, and mitral valve regurgitation. Comprehensive clinical evaluation entails both hemodynamic analysis and structural as well as functional characterization of the left ventricle. Cardiac magnetic resonance imaging (MRI) is an established diagnostic modality for assessment of left‐sided VHD and is progressively gaining ground in modern‐day clinical practice. Detailed flow visualization and quantification of flow‐related biomarkers in VHD can be obtained using 4D flow MRI, an imaging technique capable of measuring blood flow in three orthogonal directions over time. In addition, recent MRI sequences enable myocardial tissue characterization and strain analysis. In this review we discuss the emerging potential of state‐of‐the‐art MRI including 4D flow MRI, tissue mapping, and strain quantification for the diagnosis and prognosis of left‐sided VHD.

Level of Evidence: 1

Technical Efficacy Stage: 1

J. Magn. Reson. Imaging 2018. J. MAGN. RESON. IMAGING 2018;48:318–329.

Aortic valvular imaging with cardiovascular magnetic resonance: seeking for comprehensiveness

Cardiovascular magnetic resonance (CMR) has an emerging role in aortic valve disease evaluation, becoming an all-in-one technique. CMR evaluation of the anatomy and flow through the aortic valve has a higher reproducibility than echocardiography. Its unique ability of in vivo myocardial tissue characterization, significantly improves the risk stratification and management of patients. In addition, CMR is equivalent to cardiac CT angiography for trans-aortic valvular implantation and surgical aortic valve replacement planning; on the other hand, its role in the evaluation of ventricular function improving and post-treatment complications is undisputed. This review encompasses the existing literature regarding the role of CMR in aortic valve disease, exploring all the aspects of the disease, from diagnosis to prognosis.

Imaging and Impact of Myocardial Fibrosis in Aortic Stenosis

Aortic stenosis is characterized both by progressive valve narrowing and the left ventricular remodeling response that ensues. The only effective treatment is aortic valve replacement, which is usually recommended in patients with severe stenosis and evidence of left ventricular decompensation. At present, left ventricular decompensation is most frequently identified by the development of typical symptoms or a marked reduction in left ventricular ejection fraction <50%. However, there is growing interest in using the assessment of myocardial fibrosis as an earlier and more objective marker of left ventricular decompensation, particularly in asymptomatic patients, where guidelines currently rely on nonrandomized data and expert consensus. Myocardial fibrosis has major functional consequences, is the key pathological process driving left ventricular decompensation, and can be divided into 2 categories. Replacement fibrosis is irreversible and identified using late gadolinium enhancement on cardiac magnetic resonance, while diffuse fibrosis occurs earlier, is potentially reversible, and can be quantified with cardiac magnetic resonance T1 mapping techniques. There is a substantial body of observational data in this field, but there is now a need for randomized clinical trials of myocardial imaging in aortic stenosis to optimize patient management. This review will discuss the role that myocardial fibrosis plays in aortic stenosis, how it can be imaged, and how these approaches might be used to track myocardial health and improve the timing of aortic valve replacement.

Imaging of Myocardial Fibrosis and Its Functional Correlates in Aortic Stenosis: A Review and Clinical Potential

Patients with severe aortic stenosis (AS) show progressive fibrotic changes in the myocardium, which may impair cardiac function and patient outcomes even after successful aortic valve replacement. Detection of patients who need an early operation remains a diagnostic challenge as myocardial functional changes may be subtle. In recent years, speckle tracking echocardiography (STE) and cardiac magnetic resonance mapping have been shown to provide complementary information for the assessment of left ventricular mechanics and identification of subtle damage by focal or diffuse myocardial fibrosis, respectively. Little is known, however, about how focal and diffuse myocardial fibrosis occurring in severe AS are related to measurable functional changes by echocardiography and to which extent both parameters have prognostic and diagnostic value. The aims of this review are to discuss the occurrence of focal and diffuse myocardial fibrosis in patients with severe AS and to explore their relation with myocardial function, determined by STE, as well as the prognostic and diagnostic potential of both parameters.

Role of Cardiac Magnetic Resonance Imaging in Valvular Heart Disease: Diagnosis, Assessment, and Management

PURPOSE OF REVIEW

This article will review the current techniques in cardiac magnetic resonance imaging (CMR) for diagnosing and assessing primary valvular heart disease.

RECENT FINDINGS

The recent advancements in CMR have led to an increased role of this modality for qualifying and quantifying various native valve diseases. Phase-contrast velocity encoded imaging is a well-established technique that can be used to quantify aortic and pulmonic flow. This technique, combined with the improved ability for CMR to obtain accurate left and right ventricular volumetrics, has allowed for increased accuracy and reproducibility in assessing valvular dysfunction. Advancements in CMR technology also allows for improved spatial and temporal resolution imaging of various valves and their regurgitant or stenotic jets. Therefore, CMR can be a powerful tool in evaluation of native valvular heart disease. The role of CMR in assessing valvular heart disease is growing and being recognized in recent guidelines. CMR has the ability to assess valve morphology along with qualifying and quantifying valvular disease. In addition, the ability to obtain accurate volumetric measurements may improve more precise management strategies and may lead to improvements in mortality and morbidity.

Sudden Cardiac Death Risk Prediction: The Role of Cardiac Magnetic Resonance Imaging

Sudden cardiac death (SCD) accounts for more than 4 million global deaths per year. While it is most commonly caused by coronary artery disease, a final common pathway of ventricular arrhythmias is shared by different etiologies. The most effective primary and secondary prevention strategy is an implantable cardioverter-defibrillator (ICD). The decision to implant an ICD for primary prevention is largely based on a left ventricular ejection fraction ≤ 35%, but this criterion in isolation is neither sensitive nor specific. Novel imaging parameters hold promise to improve ICD candidate selection. Cardiac magnetic resonance (CMR) imaging is a powerful and versatile technique, with the ability to comprehensively assess cardiac structure and function. A range of variables based on CMR techniques (late gadolinium enhancement, T₁ mapping, T₂* relaxometry, deformation imaging) have been associated with ventricular arrhythmias and SCD risk. The role of CMR in the estimation of ventricular arrhythmias and SCD risk in coronary artery disease, nonischemic cardiomyopathies, cardiac transplant, iron-overload cardiomyopathy and valvular heart disease is reviewed in this article. Prospective, randomized trials and standardization of CMR techniques are required before its routine use can be recommended for guiding SCD prevention strategies.

Specific biomarkers of myocardial inflammation and remodeling processes as predictors of mortality in high-risk patients undergoing percutaneous mitral valve repair (MitraClip)

BACKGROUND

Specific matrix metalloproteinases (MMP-2, MMP-9) and inflammatory biomarkers (hsCRP, IL-6) were found to be consistently up-regulated in severe mitral valve regurgitation (MR) and are associated with mortality in heart failure patients. The aim of the present study was to examine the prognostic value of biomarkers of cardiac inflammation and remodeling processes in predicting mortality in patients with MR undergoing percutaneous mitral valve repair (PMVR).

HYPOTHESIS

We hypothesize that increased cardiac inflammation and extracellular matrix turnover is predictive for mortality in patients with severe mitral regurgitation undergoing MitraClip.

METHODS

A total of 210 consecutive patients undergoing PMVR were included. PMVR was performed according to standard clinical practice. Venous blood samples for biomarker analyses were collected prior to and 6 months after PMVR. Physiological parameters, medication use, safety events, and all-cause mortality were followed over 12 months.

RESULTS

PMVR was performed successfully in all patients. Twelve months after PMVR there was an effective reduction in the severity of MR (P < 0.001), and an improvement in New York Heart Association class (P < 0.01) was documented. Elevated inflammatory biomarkers (AUC_hsCRP : 0.738 [IQR, 0.626-0.849], P = 0.001; AUC_IL-6 : 0.811 [IQR, 0.724-0.899], P = 0.001) and biomarkers reflecting cardiac remodeling processes (AUC_MMP-2 : 0.723 [IQR, 0.641-0.804], P = 0.001; AUC_MMP-9 : 0.618 [IQR, 0.534-0.701], P = 0.01) were predictors of adverse cardiac events and mortality in patients with congestive heart failure undergoing PMVR.

CONCLUSIONS

The present study is the first to identify biomarkers reflecting inflammation (hsCRP, IL-6) and cardiac remodeling processes (MMP-2, MMP-9) as predictors of mortality in high-risk patients undergoing PMVR.