The combination of carboxy-terminal propeptide of procollagen type I blood levels and late gadolinium enhancement at cardiac magnetic resonance provides additional prognostic information in idiopathic dilated cardiomyopathy - A multilevel assessment of myocardial fibrosis in dilated cardiomyopathy

Aims To determine the prognostic value of multilevel assessment of fibrosis in dilated cardiomyopathy (DCM) patients. Methods and results We quantified fibrosis in 209 DCM patients at three levels: (i) non-invasive late gadolinium enhancement (LGE) at cardiac magnetic resonance (CMR); (ii) blood biomarkers [amino-terminal propeptide of procollagen type III (PIIINP) and carboxy-terminal propeptide of procollagen type I (PICP)], (iii) invasive endomyocardial biopsy (EMB) (collagen volume fraction, CVF). Both LGE and elevated blood PICP levels, but neither PIIINP nor CVF predicted a worse outcome defined as death, heart transplantation, heart failure hospitalization, or life-threatening arrhythmias, after adjusting for known clinical predictors [adjusted hazard ratios: LGE 3.54, 95% confidence interval (CI) 1.90-6.60; P < 0.001 and PICP 1.02, 95% CI 1.01-1.03; P = 0.001]. The combination of LGE and PICP provided the highest prognostic benefit in prediction (likelihood ratio test P = 0.007) and reclassification (net reclassification index: 0.28, P = 0.02; and integrated discrimination improvement index: 0.139, P = 0.01) when added to the clinical prediction model. Moreover, patients with a combination of LGE and elevated PICP (LGE+/PICP+) had the worst prognosis (log-rank P < 0.001). RNA-sequencing and gene enrichment analysis of EMB showed an increased expression of pro-fibrotic and pro-inflammatory pathways in patients with high levels of fibrosis (LGE+/PICP+) compared to patients with low levels of fibrosis (LGE-/PICP-). This would suggest the validity of myocardial fibrosis detection by LGE and PICP, as the subsequent generated fibrotic risk profiles are associated with distinct cardiac transcriptomic profiles. Conclusion The combination of myocardial fibrosis at CMR and circulating PICP levels provides additive prognostic value accompanied by a pro-fibrotic and pro-inflammatory transcriptomic profile in DCM patients with LGE and elevated PICP

Predictive imaging for thoracic aortic dissection and rupture:moving beyond diameters

Acute aortic syndromes comprise a group of potentially fatal conditions that result from weakening of the aortic vessel wall. Pre-emptive surgical intervention is currently reserved for patients with severe aortic dilatation, although abundant evidence describes the occurrence of dissection and rupture in aortas with diameters below surgical thresholds. Modern imaging techniques (such as hybrid PET-CT and 4D flow MRI) afford the non-invasive assessment of anatomic, hemodynamic, and molecular features of the aorta, and may provide for a more accurate selection of patients who will benefit from preventative surgical intervention. In the current review, we summarize evidence and considerations regarding predictive aortic imaging and highlight evolving imaging modalities that have shown promise to improve risk assessment for the occurrence of dissection and rupture.Key PointsGuidelines for the preventative management of aortic disease depend on maximal vessel diameters, while these have shown to be poor predictors for the occurrence of catastrophic acute aortic events.Evolving imaging modalities (such as 4D flow MRI and hybrid PET-CT) afford a more comprehensive insight into anatomic, hemodynamic, and molecular features of the aorta and have shown promise to detect vessel wall instability at an early stage.Cardiovascular Aspects of Radiolog

A clinician’s guide to understanding aortic 4D flow MRI

Abstract Four-dimensional flow magnetic resonance imaging is an emerging technique which may play a role in diagnosis and risk-stratification of aortic disease. Some knowledge of flow dynamics and related parameters is necessary to understand and apply this technique in clinical workflows. The purpose of the current review is to provide a guide for clinicians to the basics of flow imaging, frequently used flow-related parameters, and their relevance in the context of aortic disease. Clinical relevance statement Understanding normal and abnormal aortic flow could improve clinical care in patients with aortic disease. Graphical abstrac

Correlation between Cardiac MRI and Voltage Mapping in Evaluating Atrial Fibrosis:A Systematic Review

PURPOSE: To provide an overview of existing literature on the association between late gadolinium enhancement (LGE) cardiac MRI and low voltage areas (LVA) obtained with electroanatomic mapping (EAM) or histopathology when assessing atrial fibrosis. MATERIALS AND METHODS: A systematic literature search was conducted in the PubMed, Embase, and Cochrane Library databases to identify all studies published until June 7, 2022, comparing LGE cardiac MRI to LVA EAM and/or histopathology for evaluation of atrial fibrosis. The study protocol was registered at PROSPERO (registration no. CRD42022338243). Two reviewers independently evaluated the studies for inclusion. Risk of bias and applicability for each included study were assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) criteria. Data regarding demographics, electrophysiology, LGE cardiac MRI, and study outcomes were extracted. RESULTS: The search yielded 1048 total results, of which 22 studies were included. Nineteen of the 22 included studies reported a significant correlation between high signal intensity at LGE cardiac MRI and LVA EAM or histopathology. However, there was great heterogeneity between included studies regarding study design, patient samples, cardiac MRI performance and postprocessing, and EAM performance. CONCLUSION: Current literature suggests a correlation between LGE cardiac MRI and LVA EAM or histopathology when evaluating atrial fibrosis but high heterogeneity between studies, demonstrating the need for uniform choices regarding cardiac MRI and EAM acquisition in future studies.Keywords: Cardiac, MR Imaging, Left Atrium Supplemental material is available for this article. © RSNA, 2022

Extending Aortic Replacement Beyond the Proximal Arch in Acute Type A Aortic Dissection:A Meta-Analysis of Short Term Outcomes and Long Term Actuarial Survival

OBJECTIVE: The extent of aortic replacement during surgery for acute type A aortic dissection (ATAAD) is an important matter of debate. This meta-analysis aimed to evaluate the short and long term outcomes of a proximal aortic repair (PAR) vs. total arch replacement (TAR) in the treatment of ATAAD. DATA SOURCES: A systematic search of PubMed and Embase was performed. Studies comparing PAR to TAR for ATAAD were included. REVIEW METHODS: The primary outcomes were early death and long term actuarial survival at one, five, and 10 years. Random effects models in conjunction with relative risks (RRs) were used for meta-analyses. RESULTS: Nineteen studies were included, comprising 5 744 patients (proximal: n = 4 208; total arch: n = 1 536). PAR was associated with reduced early mortality (10.8% [95% confidence interval (CI) 8.4 - 13.7] vs. 14.0% [95% CI 10.4 - 18.7]; RR 0.73 [95% CI 0.63 - 0.85]) and reduced post-operative renal failure (10.4% [95% CI 7.2 - 14.8] vs. 11.1% [95% CI 6.7 - 17.5]; RR 0.77 [95% CI 0.66 - 0.90]), but there was no difference in stroke (8.0% [95% CI 5.9 - 10.7] vs. 7.3% [95% CI 4.6 - 11.3]; RR 0.87 [95% CI 0.69 - 1.10]). No statistically significant difference was found for survival after one year (83.2% [95% CI 77.5 - 87.7] vs. 78.6% [95% CI 69.7 - 85.5]; RR 1.05 [95% CI 0.99 - 1.11]), which persisted after five years (75.4% [95% CI 71.2 - 79.2] vs. 74.5% [95% CI 64.7 - 82.3]; RR 1.02 [95% CI 0.91 - 1.14]). After 10 years, there was a significant survival benefit for patients who underwent TAR (64.7% [95% CI 61.1 - 68.1] vs. 72.4% [95% CI 67.5 - 76.7]; RR 0.91 [95% CI 0.84 - 0.99]). CONCLUSION: PAR appears to lead to an improved early mortality rate and a reduced complication rate. In the current meta-analysis, the suggestion of an improved 10 year survival benefit of TAR was found, which should be interpreted in the context of potential confounders such as age at presentation, comorbidities, and haemodynamic stability. In any case, PAR seems to be intuitive in older patients with limited dissections, and in those presenting in less stable conditions

Clinical assessment of aortic valve stenosis:Comparison between 4D flow MRI and transthoracic echocardiography

Background The prevalence of valvular aortic stenosis (AS) increases as the population ages. Echocardiographic measurements of peak jet velocity (V-peak), mean pressure gradient (P-mean), and aortic valve area (AVA) determine AS severity and play a pivotal role in the stratification towards valvular replacement. A multimodality imaging approach might be needed in cases of uncertainty about the actual severity of the stenosis. Purpose To compare four-dimensional phase-contrast magnetic resonance (4D PC-MR), two-dimensional (2D) PC-MR, and transthoracic echocardiography (TTE) for quantification of AS. Study Type Prospective. Population Twenty patients with various degrees of AS (69.3 +/- 5.0 years). Field Strength/Sequences 4D PC-MR and 2D PC-MR at 3T. Assessment We compared V-peak, P-mean, and AVA between TTE, 4D PC-MR, and 2D PC-MR. Flow eccentricity was quantified by means of normalized flow displacement, and its influence on the accuracy of TTE measurements was investigated. Statistical Tests Pearson's correlation, Bland-Altman analysis, paired t-test, and intraclass correlation coefficient. Results 4D PC-MR measured higher V-peak (r = 0.95, mean difference + 16.4 +/- 10.7%,

Evaluating a Phase-Specific Approach to Aortic Flow:A 4D Flow MRI Study

Background: Aortic flow parameters can be quantified using 4D flow MRI. However, data are sparse on how different methods of analysis influence these parameters and how these parameters evolve during systole.Purpose: To assess multiphase segmentations and multiphase quantification of flow-related parameters in aortic 4D flow MRI.Study Type: Prospective.Population: 40 healthy volunteers (50% male, 28.9 +/- 5.0 years) and 10 patients with thoracic aortic aneurysm (80% male, 54 +/- 8 years).Field Strength/Sequence: 4D flow MRI with a velocity encoded turbo field echo sequence at 3 T.Assessment: Phase-specific segmentations were obtained for the aortic root and the ascending aorta. The whole aorta was segmented in peak systole. In all aortic segments, time to peak (TTP; for flow velocity, vorticity, helicity, kinetic energy, and viscous energy loss) and peak and time-averaged values (for velocity and vorticity) were calculated.Statistical Tests: Static vs. phase-specific models were assessed using Bland-Altman plots. Other analyses were performed using phase-specific segmentations for aortic root and ascending aorta. TTP for all parameters was compared to TTP of flow rate using paired t-tests. Time-averaged and peak values were assessed using Pearson correlation coefficient. P &lt; 0.05 was considered statistically significant.Results: In the combined group, velocity in static vs. phase-specific segmentations differed by 0.8 cm/sec for the aortic root, and 0.1 cm/sec (P = 0.214) for the ascending aorta. Vorticity differed by 167 sec(-1) mL(-1) (P = 0.468) for the aortic root, and by 59 sec(-1) mL(-1) (P = 0.481) for the ascending aorta. Vorticity, helicity, and energy loss in the ascending aorta, aortic arch, and descending aorta peaked significantly later than flow rate. Time-averaged velocity and vorticity values correlated significantly in all segments.Data Conclusion: Static 4D flow MRI segmentation yields comparable results as multiphase segmentation for flow-related parameters, eliminating the need for time-consuming multiple segmentations. However, multiphase quantification is necessary for assessing peak values of aortic flow-related parameters

Evaluating the diagnostic accuracy of maximal aortic diameter, length and volume for prediction of aortic dissection

Objective Management of thoracic aortic aneurysms (TAAs) comprises regular diameter follow-up until the indication criterion for prophylactic surgery is reached. However, this approach is unable to predict the majority of acute type A aortic dissections (ATAADs). The current study aims to evaluate the diagnostic accuracy of ascending aortic diameter, length and volume for occurrence of ATAAD. Methods This two-centre observational cohort study retrospectively screened 477 consecutive patients who presented with ATAAD between 2009 and 2018. Of those, 25 (5.2%) underwent CT angiography (CTA) within 2 years before dissection onset. Aortic diameter, length and volume of these patients ('pre-ATAAD') were compared with those of TAA controls (n=75). Receiver operating curve analysis was performed to evaluate the predictive accuracy of the three different measurements. Results 96% of patients with pre-ATAAD did not meet the surgical diameter threshold of 55 mm before dissection onset. Maximal aortic diameters (45 (40-49) mm vs 46 (44-49) mm, p=0.075) and volume (126 (95-157) cm(3) vs 124 (102-136) cm(3), p=0.909) were comparable between patients with pre-ATAAD and TAA controls. Conversely, ascending aortic length (84 +/- 9 mm vs 90 +/- 16 mm, p=0.031) was significantly larger in patients with pre-ATAAD. All three parameters had an area under the curve of >0.800. At the 55 mm cut-off point, the maximal diameter yielded a positive predictive value (PPV) of 20%. While maintaining same specificity levels, measurements of aortic volume and length showed superior diagnostic accuracy (PPV 55% and 70%, respectively). Conclusion Measurements of aortic volume and length have superior diagnostic accuracy compared with the maximal diameter and could improve the timely identification of patients at risk for ATAAD