Cardiovascular Magnetic Resonance Measurements Research Articles

Bone health, cardiovascular disease, and imaging outcomes in UK Biobank: a causal analysis.

This study examined the association of estimated heel bone mineral density (eBMD, derived from quantitative ultrasound) with: (1) prevalent and incident cardiovascular diseases (CVDs: ischemic heart disease (IHD), myocardial infarction (MI), heart failure (HF), non-ischemic cardiomyopathy (NICM), arrhythmia), (2) mortality (all-cause, CVD, IHD), and (3) cardiovascular magnetic resonance (CMR) measures of left ventricular and atrial structure and function and aortic distensibility, in the UK Biobank. Clinical outcomes were ascertained using health record linkage over 12.3yr of prospective follow-up. Two-sample Mendelian randomization (MR) was conducted to assess causal associations between BMD and CMR metrics using genetic instrumental variables identified from published genome-wide association studies. The analysis included 485 257 participants (55% women, mean age 56.5±8.1yr). Higher heel eBMD was associated with lower odds of all prevalent CVDs considered. The greatest magnitude of effect was seen in association with HF and NICM, where 1-SD increase in eBMD was associated with 15% lower odds of HF and 16% lower odds of NICM. Association between eBMD and incident IHD and MI was non-significant; the strongest relationship was with incident HF (SHR: 0.90 [95% CI, 0.89-0.92]). Higher eBMD was associated with a decreased risk in all-cause, CVD, and IHD mortality, in the fully adjusted model. Higher eBMD was associated with greater aortic distensibility; associations with other CMR metrics were null. Higher heel eBMD is linked to reduced risk of a range of prevalent and incident CVD and mortality outcomes. Although observational analyses suggest associations between higher eBMD and greater aortic compliance, MR analysis did not support a causal relationship between genetically predicted BMD and CMR phenotypes. These findings support the notion that bone-cardiovascular associations reflect shared risk factors/mechanisms rather than direct causal pathways.

Non-invasive pressure-volume loops using the elastance model and CMR: a porcine validation at transient pre-loads.

Pressure-volume (PV) loops have utility in the evaluation of cardiac pathophysiology but require invasive measurements. Recently, a time-varying elastance model to derive PV loops non-invasively was proposed, using left ventricular (LV) volume by cardiovascular magnetic resonance (CMR) and brachial cuff pressure as inputs. Validation was performed using CMR and pressure measurements acquired on the same day, but not simultaneously, and without varying pre-loads. This study validates the non-invasive elastance model used to estimate PV loops at varying pre-loads, compared with simultaneous measurements of invasive pressure and volume from real-time CMR, acquired concurrent to an inferior vena cava (IVC) occlusion. We performed dynamic PV loop experiments under CMR guidance in 15 pigs (n = 7 naïve, n = 8 with ischaemic cardiomyopathy). Pre-load was altered by IVC occlusion, while simultaneously acquiring invasive LV pressures and volumes from real-time CMR. Pairing pressure and volume signals yielded invasive PV loops, and model-based PV loops were derived using real-time LV volumes. Haemodynamic parameters derived from invasive and model-based PV loops were compared. Across 15 pigs, 297 PV loops were recorded. Intra-class correlation coefficient (ICC) agreement was excellent between model-based and invasive parameters: stroke work (bias = 0.007 ± 0.03 J, ICC = 0.98), potential energy (bias = 0.02 ± 0.03 J, ICC = 0.99), ventricular energy efficiency (bias = -0.7 ± 2.7%, ICC = 0.98), contractility (bias = 0.04 ± 0.1 mmHg/mL, ICC = 0.97), and ventriculoarterial coupling (bias = 0.07 ± 0.15, ICC = 0.99). All haemodynamic parameters differed between naïve and cardiomyopathy animals (P < 0.05). The invasive vs. model-based PV loop dice similarity coefficient was 0.88 ± 0.04. An elastance model-based estimation of PV loops and associated haemodynamic parameters provided accurate measurements at transient loading conditions compared with invasive PV loops.

Assessment of right ventricular diastolic function in pediatric patients with repaired tetralogy of Fallot by cardiovascular magnetic resonance and echocardiography.

Cardiovascular magnetic resonance (CMR) imaging is routinely performed for assessing right ventricular (RV) systolic but not diastolic function. We aimed to investigate CMR-based assessment of RV diastolic function in pediatric patients with repaired tetralogy of Fallot (rTOF), compared to transthoracic echocardiography (TTE) measurements. A total of 130 consecutive pediatric patients with rTOF who underwent clinically indicated CMR and same-day TTE were included. Forty-three controls were recruited. Phase-contrast images were used to measure trans-tricuspid valve flow velocities during early (E) and late diastolic (A) phases (measured in cm/s). Feature tracking of the tricuspid annulus was performed to derive early (e') and late diastolic (a') myocardial velocities (measured in cm/s). RV diastolic function was evaluated by E/A ratio, E/e' ratio, and E-wave deceleration time (measured in milliseconds). Regression analyses were utilized to identify potential variables associated with RV diastolic dysfunction (DD). The performance of CMR-derived parameters in diagnosing RV DD was assessed using receiver-operating characteristic analyses. Good agreement was found between CMR and TTE measurements (ICC 0.70-0.89). Patients with RV DD (n = 67) showed significantly different CMR-derived parameters including E and e' velocities, and E/A and E/e' ratio, compared to patients without DD (n = 63) (all p < 0.05). CMR-derived E and e' velocities and E/e' ratio were independent predictors of RV DD. E/e' of 5.8 demonstrated the highest discrimination of RV DD (AUC 0.76, sensitivity 70%, specificity 86%). CMR-derived parameters showed good agreement with TTE parameters in determining RV DD. CMR-derived E/e' was proved to be the most effective in identifying RV DD. This study demonstrated the feasibility and efficacy of CMR in assessing diastolic function in pediatric patients. RV DD was presented in over half of patients according to current TTE guidelines, highlighting the need for assessing RV diastolic function during follow-up. • Routinely acquired cine and phase-contrast cardiovascular magnetic resonance (CMR) images yielded right ventricular (RV) diastolic parameters which demonstrated good agreement with transthoracic echocardiography (TTE) measurements. • There was a high prevalence of RV diastolic function impairment in pediatric patients with repaired tetralogy of Fallot (rTOF). • CMR is a reliable complementary modality of TTE for RV diastolic function evaluation.

Mitral valve orifice area predicts outcome after biventricular repair in patients with hypoplastic left ventricles

BackgroundIdentification of risk factors for biventricular (BiV) repair in children with hypoplastic left ventricles (HLV) has been challenging. We sought to identify preoperative cardiovascular magnetic resonance (CMR) predictors of outcome in patients with HLVs who underwent BiV repair, with a focus on the mitral valve (MV). MethodsSingle center retrospective analysis of preoperative CMRs on patients with HLV (≤50ml/m2) and no endocardial fibroelastosis who underwent BiV repair from 2005-2022. CMR measurements included MV orifice area in diastole. The primary composite outcome included time to death, transplant, BiV takedown, heart failure admission, left atrial decompression, or unexpected reoperation; and the secondary outcome included ≥ moderate mitral stenosis and/or regurgitation. ResultsMedian follow-up was 0.7 (IQR 0.1, 2.2) years. Of 122 patients [48% atrioventricular canal (AVC) and 52% non-AVC] age 3 ± 2.8 years at the time of BiV repair, freedom from the primary outcome at 2 years was 53% for AVC and 69% for non-AVC (log rank p=0.12), and freedom from the secondary outcome at 2 years was 49% for AVC and 79% for non-AVC (log rank p<0.01). Independent predictors of primary outcome for AVC patients included MV orifice area z-score < -2 and transitional AVC; for non-AVC patients, predictors included MV orifice area z-score < -2, abnormal MV anatomy, and conal-septal ventricular septal defect. Independent predictors of secondary outcome for AVC patients included older age at surgery, transitional AVC, and transposition of the great arteries. ConclusionsIn children with HLV, low MV orifice area and pre-existing MV pathology are risk factors for adverse outcome after BiV repair.

Myocardial Fibrosis Improves in Young Patients with Sickle Cell Disease after Hematopoietic Cell Transplantation

Introduction: Cardiovascular complications are a leading cause of early mortality in patients with sickle cell disease (SCD). Chronic anemia, iron overload and repeated microvascular ischemic insults with reperfusion injury often result in progressive myocardial injury and maladaptive remodeling in SCD patients. Patients with SCD develop diffuse myocardial fibrosis, which can be detected by quantifying the myocardial extracellular volume (ECV) using cardiovascular magnetic resonance (CMR) imaging. Our group and others have previously shown that diffuse myocardial fibrosis is highly prevalent in both children and young adults with SCD, including those who have normal ventricular size and function by echocardiography. Additionally, we have shown that the disease modifying therapies (DMT) such as hydroxyurea or chronic transfusions do not appear to be protective against development of diffuse myocardial fibrosis. In a retrospective study, we found no difference in the myocardial ECV in patients who began DMT early (less than 6 years of age) versus later in life (at least 6 years or after) (Morin CE and Sharma A et al. Blood 2023.). Hematopoietic cell transplantation (HCT) can cure SCD, but myocardial effects of the therapy are unknown. Our goal was to evaluate cardiovascular parameters of function and injury, especially the progression of diffuse myocardial fibrosis, by comparing serial CMR studies performed before and after HCT in patients with SCD. Methods: We performed prospective CMR evaluation of children and young adults with SCD who received a matched sibling donor (MSD) or haploidentical donor (HAPLO) HCT following a reduced toxicity conditioning on a clinical trial (NCT04362293). CMR was performed pre-HCT, and at 1 month, and 12 months post-HCT. CMR-derived ventricular and atrial volumes were calculated. ECV was measured from T1 maps with a modified Look-Locker inversion recovery (MOLLI) sequence in short-axis. T2 and T2* maps were obtained. Regions of interest in the mid-ventricular septum were identified for analysis. We report descriptive statistics for CMR measures along with paired t-tests comparing patient ECV levels at 1-month and 12-months post-HCT to their respective baseline ECV. Results: Our study cohort consisted of 14 patients with SCD who underwent HCT and had serial CMR evaluations available. Thirteen patients had HbSS genotype and one had HbSC genotype. All patients were receiving DMT, either with hydroxyurea or chronic transfusions prior to HCT. Participants were majority male (57%) with median age of 15.2 years (range 6.8-21.3) at the pre-HCT CMR. Six received an MSD HCT and 8 received a HAPLO HCT. Ten patients each had follow up CMR evaluations performed at 1 month, and 12 months post-HCT. At 1 and 12 months post-HCT ejection fraction was preserved while biventricular volume and cardiac index decreased (Table 1). Compared to pre-HCT, ECV decreased from median 29% [range 27-38] to 28% (range 21-35, P= 0.061) at 1 month and 27% (range 24-31, P= 0.043) at 12 months post-HCT. There was no difference in the cardiac chamber sizes or the ECV measurements of those who received a MSD versus HAPLO HCT. Conclusions: We observed an improvement in cardiac chamber sizes with preservation of cardiac function as early as one month after HCT in patients with SCD. We further noted a reduction in ECV indicating a decrease in diffuse myocardial fibrosis in these young patients with SCD. To our knowledge, this is the first study to show that diffuse myocardial fibrosis can improve in patients with SCD after HCT. In addition to further corroborating the organ function protective effects of HCT in patients with SCD, these data further demonstrate the use of CMR as an essential non-invasive tool to assess the effects of therapeutic interventions on SCD-cardiac injury.

Higher subclinical cardiac fibrosis in South African youth with HIV: results from the CTAAC-heart study

Abstract Background Few data exist on cardiac fibrosis and inflammation in youth with HIV, particularly in sub-Saharan Africa. Purpose Our objective was to assess the association between HIV status and cardiovascular magnetic resonance (CMR) measures of subclinical cardiac fibrosis, inflammation, and function. Methods We performed CMR on a cross-section of youth in South Africa: youth with perinatally acquired HIV (YPHIV), youth with non-perinatally acquired HIV (YNPHIV), and HIV-seronegative youth (YHIV-). Subclinical fibrosis [late gadolinium enhancement (LGE) mass and fraction, extracellular volume (ECV)], inflammation [native T1 and T2 mapping], and cardiac function (cine, strain, and strain rate) were assessed. CD4, viral load (VL), and fasting glucose, insulin [for Homeostatic Model Assessment-Insulin Resistance (HOMA)] and lipids were obtained. Unadjusted and adjusted quantile regression models were used to assess the association between HIV status and CMR outcomes. In sub-group analyses of youth with HIV, we additionally adjusted for HIV factors. Results Of 464 youth, 287 were YPHIV, 87 YNPHIV, and 90 YHIV-. YNPHIV were older with a higher proportion self-identifying as female than YPHIV and YHIV- (median age 20 vs 18 and 17 years; 85% vs 50% and 49%, respectively). YPHIV had lower body surface area (1.6 vs 1.7 and 1.7m2) and a higher proportion with prior TB disease (70% vs. 20% vs 8%) compared to YNPHIV and YHIV-. Tobacco use, HOMA, total cholesterol, and low-density lipoproteins were similar between groups. Among youth with HIV, YPHIV had a higher proportion with CD4&amp;lt;200 cells/mm3 (10% vs 4%) or VL&amp;gt;50 copies/mL (39% vs 13%) but lower proportion on integrase inhibitors (33% vs 84%). LGE mass (0.13 vs 0.12 vs 0.07g respectively) and fraction (0.3% vs 0.3% vs. 0.2% respectively) were higher in YPHIV and YNPHIV than YHIV-; native T1 was highest in YNPHIV compared to YPHIV and YHIV- (Table). In adjusted analyses, compared to YHIV-, median LGE mass was higher in YPHIV and YNPHIV (β:0.06, p=0.01 for YPHIV, β:0.05, p=0.03 for YNPHIV) and LGE% was higher in YPHIV (β:0.14, p=0.02); native T1 and ECV did not differ between groups in adjusted analyses. Among youth with HIV, CMR outcomes did not differ significantly for persons with perinatal vs non-perinatal HIV. Findings did not vary in analyses restricted to females. Conclusion In one of the largest studies of CMR among youth with HIV in sub-Saharan Africa, we found that despite their young age, YPHIV and YNPHIV appear to have higher subclinical cardiac fibrosis than YHIV- and healthy adults in South Africa. Youth with HIV may benefit from early screening and long-term monitoring for cardiovascular disease.TableFigure

Abstract 17366: Effects of Acute Maternal Supplemental Oxygen on the Fetal Circulation in Transposition of the Great Arteries

Introduction: The presence of a restrictive atrial septum in the setting of transposition of the great arteries (TGA) is associated with a high risk of hypoxic ischemic injury upon transition to postnatal circulation. Fetal cardiovascular magnetic resonance (CMR) measures of vessel flow and oxygen saturation provide a unique opportunity to study fetal TGA hemodynamics at baseline and during acute maternal hyperoxygenation. Methods: Thirty-one pregnant mothers with fetuses diagnosed with TGA and an intact ventricular septum (n=23) or small ventricular septal defect (n=8) were recruited and underwent fetal CMR in room air and during administration of 10L/min of oxygen by face mask for up to 45 minutes. Blood flow and oxygen saturations were measured in the major fetal vessels using cine phase contrast MRI and MR relaxometry at baseline and during hyperoxygenation. Results: Two patients exhibited severe restriction at the atrial septum, one undergoing fetal atrial septostomy at 37 weeks and one requiring cannulation onto ECMO shortly after birth. Both revealed reversal of the usual relationship of oxygen saturation between the aorta and the main pulmonary artery at baseline and during hyperoxygenation, i.e. in TGA with restrictive atrial septum the saturations are higher in the aorta than pulmonary. Acute maternal supplemental oxygen was associated with increased pulmonary blood flow (p=0.008) and reduced foramen ovale (p=0.01) and ductus arteriosus shunting (p=0.01). There were no significant changes in umbilical vein, descending aorta and superior vena cava flow. Fetal oxygen saturations increased throughout fetal circulation (p&lt;0.0001) with an associated increase in fetal oxygen delivery (p=0.007), but no increase in fetal cerebral oxygen delivery (p=0.58). Conclusions: This study characterized the effects of acute maternal supplemental oxygen on the fetal circulation in patients with TGA and confirmed the redistribution of flow toward the fetal pulmonary circulation. We observed higher oxygen saturations in the aorta than main pulmonary artery in fetuses with TGA with an intact or highly restrictive atrial septal communication. This finding could be helpful in selecting patients for prenatal or emergency neonatal balloon atrial septostomy.

Physical exercise and cardiovascular response: design and implementation of a pediatric CMR cohort study

To examine feasibility and reproducibility and to evaluate the cardiovascular response to an isometric handgrip exercise in low-risk pediatric population using Cardiovascular Magnetic Resonance measurements. In a subgroup of 207 children with a mean age of 16 years participating in a population-based prospective cohort study, children performed an isometric handgrip exercise. During rest and exercise, continuous heart rate and blood pressure were measured. Cardiovascular magnetic resonance (CMR) measurements included left ventricular mass, aortic distensibility and pulse wave velocity at rest and left ventricular end-diastolic and end-systolic volumes, ejection fraction, stroke volume and cardiac output during rest and exercise. 207 children had successful CMR measurements in rest and 184 during exercise. We observed good reproducibility for all cardiac measurements. Heart rate increased with a mean ± standard deviation of 42.6% ± 20.0 and blood pressure with 6.4% ± 7.0, 5.4% ± 6.1 and 11.0% ± 8.3 for systolic, diastolic and mean arterial blood pressure respectively (p-values < 0.05). During exercise, left ventricular end-diastolic and end-systolic volumes and cardiac output increased, whereas left ventricular ejection fraction slightly decreased (p-values < 0.05). Stroke volume did not change significantly. A sustained handgrip exercise of 7 min at 30–40% maximal voluntary contraction is a feasible exercise-test during CMR in a healthy pediatric population, which leads to significant changes in heart rate, blood pressure and functional measurements of the left ventricle in response to exercise. This approach offers great novel opportunities to detect subtle differences in cardiovascular health.

Neuroticism personality traits are linked to adverse cardiovascular phenotypes in the UK Biobank.

To evaluate the relationship between neuroticism personality traits and cardiovascular magnetic resonance (CMR) measures of cardiac morphology and function, considering potential differential associations in men and women. The analysis includes 36 309 UK Biobank participants (average age = 63.9 ± 7.7 years; 47.8% men) with CMR available and neuroticism score assessed by the 12-item Eysenck Personality Questionnaire-Revised Short Form. CMR scans were performed on 1.5 Tesla scanners (MAGNETOM Aera, Siemens Healthcare, Erlangen, Germany) according to pre-defined protocols and analysed using automated pipelines. We considered measures of left ventricular (LV) and right ventricular (RV) structure and function, and indicators of arterial compliance. Multivariable linear regression was used to estimate association of neuroticism score with individual CMR metrics, with adjustment for age, sex, obesity, deprivation, smoking, diabetes, hypertension, hypercholesterolaemia, alcohol use, exercise, and education. Higher neuroticism scores were associated with smaller LV and RV end-diastolic volumes, lower LV mass, greater concentricity (higher LV mass to volume ratio), and higher native T1. Greater neuroticism was also linked to poorer LV and RV function (lower stroke volumes) and greater arterial stiffness. In sex-stratified analyses, the relationships between neuroticism and LV stroke volume, concentricity, and arterial stiffness were attenuated in women. In men, association (with exception of native T1) remained robust. Greater tendency towards neuroticism personality traits is linked to smaller, poorer functioning ventricles with lower LV mass, higher myocardial fibrosis, and higher arterial stiffness. These relationships are independent of traditional vascular risk factors and are more robust in men than women.

Association of cardiovascular magnetic resonance diastolic indices with arrhythmia in repaired Tetralogy of Fallot

BackgroundPatients with repaired Tetralogy of Fallot (rTOF) experience a high burden of long-term morbidity, particularly arrhythmias. Cardiovascular magnetic resonance (CMR) is routinely used to assess ventricular characteristics but the relationship between CMR diastolic function and arrhythmia has not been evaluated. We hypothesized in rTOF, left ventricular (LV) diastolic dysfunction on CMR would correlate with arrhythmias and mortality. MethodsAdolescents and adults with rTOF who underwent CMR were compared to healthy controls (n = 58). Standard ventricular parameters were assessed and manual planimetry was performed to generate filling curves and indices of diastolic function. Chart review was performed to collect outcomes. Univariate and multivariable logistic regression was performed to identify outcome associations. ResultsOne-hundred sixty-seven subjects with rTOF (mean age 32 years) and 58 healthy control subjects underwent CMR. Patients with rTOF had decreased LV volumes and increased right ventricular (RV) volumes, lower RV ejection fraction (RVEF), lower peak ejection rate (PER), peak filling rate (PFR) and PFR indexed to end-diastolic volume (PFR/EDV) compared to healthy controls. Eighty-three subjects with rTOF had arrhythmia (63 atrial, 47 ventricular) and 11 died. Left atrial (LA) volumes, time to peak filling rate (tPFR), and PFR/EDV were associated with arrhythmia on univariate analysis. PER/EDV was associated with ventricular (Odds ratio, OR 0.43 [0.24–0.80], p = 0.007) and total arrhythmia (OR 0.56 [0.37–0.92], p = 0.021) burden. A multivariable predictive model including diastolic covariates showed improved prediction for arrhythmia compared to clinical and conventional CMR measures (area under curve (AUC) 0.749 v. 0.685 for overall arrhythmia). PFR/EDV was decreased and tPFR was increased in rTOF subjects with mortality as compared to those without mortality. ConclusionsSubjects with rTOF have abnormal LV diastolic function compared to healthy controls. Indices of LV diastolic function were associated with arrhythmia and mortality. CMR diastolic indices may be helpful in risk stratification for arrhythmia.

Subclinical Systemic Sclerosis Primary Heart Involvement by Cardiovascular Magnetic Resonance Shows No Significant Interval Change.

Subclinical systemic sclerosis (SSc) primary heart involvement is commonly described. Whether these findings progress over time is not clear. The study aimed to investigate cardiovascular magnetic resonance (CMR) interval change of subclinical SSc primary heart involvement. Patients with SSc with no cardiovascular disease underwent two CMR scans that included T1 mapping and quantitative stress perfusion. The CMR change (mean difference) and association between CMR measures and clinical phenotype were assessed. The study had a prospective design. Thirty-one patients with SSc participated, with a median (interquartile range) follow-up of 33 (17-37) months (10 [32%] in the diffuse subset, 16 [52%] with interstitial lung disease [ILD], and 11 [29%] who were Scl-70+). Four of thirty-one patients had focal late gadolinium enhancement (LGE) at visit 1; one of four had an increase in LGE scar mass between visits. Two patients showed new focal LGE at visit 2. No change in other CMR indices was noted. The three patients with SSc with increased or new LGE at visit 2 had diffuse cutaneous SSc with ILD, and two were Scl-70+. A reduction in forced vital capacity and total lung capacity was associated with a reduction in left ventricular ejection fraction (ρ= 0.413, P= 0.021; ρ= 0.335, P= 0.07) and myocardial perfusion reserve (MPR) (ρ= 0.543, P= 0.007; ρ= 0.627, P= 0.002). An increase in the N-terminal pro-brain natriuretic peptide level was associated with a reduction in MPR (ρ= -0.448, P= 0.042). Patients on disease-modifying antirheumatic drugs (DMARDs) had an increase in native T1 (mean [SD] 1208 [65] vs. 1265 [56] milliseconds, P= 0.008). No other clinically meaningful CMR change in patients receiving DMARDs or vasodilators was noted. Serial CMR detects interval subclinical SSc primary heart involvement progression; however, this study suggests abnormalities remain largely stable with follow-up.

Cross-Sectional Relationships of Proximal Aortic Stiffness and Left Ventricular Diastolic Function in Adults in the Community.

Background Stiffness of the proximal aorta may play a critical role in adverse left ventricular (LV)-vascular interactions and associated LV diastolic dysfunction. In a community-based sample, we sought to determine the association between proximal aortic stiffness measured by cardiovascular magnetic resonance (CMR) and several clinical measures of LV diastolic mechanics. Methods and Results Framingham Heart Study Offspring adults (n=1502 participants, mean 67±9 years, 54% women) with available 1.5T CMR and transthoracic echocardiographic measures were included. Measures included proximal descending aortic strain and aortic arch pulse wave velocity by CMR (2002-2006) and diastolic function (mitral Doppler E and A wave velocity, E wave area, and LV tissue Doppler e' velocity) by echocardiography (2005-2008). Multivariable linear regression analysis was used to relate CMR aortic stiffness measures to measures of echocardiographic LV diastolic function. All continuous variables were standardized. In multivariable-adjusted regression analyses, aortic strain was inversely associated with E wave deceleration time (estimated β=-0.10±0.032, P=0.001), whereas aortic arch pulse wave velocity was inversely associated with E/A ratio (estimated β=-0.094±0.027, P=0.0006), E wave area (estimated β=-0.070±0.027, P=0.010), and e' (estimated β=-0.061±0.027, P=0.022), all indicating associations of higher aortic stiffness by CMR with less favorable LV diastolic function. Compared with men, women had a larger inverse relationship between pulse wave velocity and E/A ratio (interaction β=-0.085±0.031, P=0.0064). There was no significant effect modification by age or a U-shaped (quadratic) relation between aortic stiffness and LV diastolic function measures. Conclusions Higher proximal aortic stiffness is associated with less favorable LV diastolic function. Future studies may clarify temporal relations of aortic stiffness with varying patterns and progression of LV diastolic dysfunction.

“Innocent” ventricular arrhythmia – can cardiovascular magnetic resonance augment diagnosis of structural heart disease?

Abstract Background Ventricular arrhythmias (VA) include a spectrum that ranges from premature ventricular beats (VPBs) to ventricular fibrillation (VF) and account for approximately 50% of all cardiovascular deaths. Echocardiography is commonly used to identify structural heart disease (SHD), the most frequent substrate of VA. Cardiovascular magnetic resonance (CMR) is recommended to complement echocardiography when image quality is suboptimal. Purpose This study sought to determine whether CMR may identify SHD in patients (pts) with VA, who had normal baseline ECGs and whose echocardiogram with fair technical conditions, ruled out pathological findings. Methods We included consecutive pts followed in arrythmia outpatient clinic of one clinical center from June 2014 to June 2021 for significant VA; this was categorized as &amp;gt;1,000 but &amp;lt;10,000 VPBs/24 h; ≥10,000 VPBs/24 h; nonsustained ventricular tachycardia (NSVT), sustained VT, or a history of resuscitated cardiac arrest, and no pathological findings at echocardiography, requiring a clinically indicated CMR. Primary endpoint was CMR detection of SHD. Data were collected at the end of the study. Results A total of 75 pts were included (no SHD: N=59; 45±15 years old; SHD: N=16, 53±15 years). All pts performed CMR, and Table 1 shows pts' baseline characteristics, VA diagnosis and CMR measurements. Definite SHD was diagnosed in 8 patients (11%): ischemic cardiopathy (three pts), myocarditis (1 pt), hypertrophic cardiomyopathy (1 pt), right ventricle arrhythmogenic disease (1 pt), non-compaction cardiomyopathy (1 pt); 1 patient presented higher myocardial T2 signal and was later diagnosed with sarcoidosis. Furthermore, abnormal findings not specific for a definite SHD diagnosis were found in other 8 pts (10%) who showed unspecific intra-myocardium enhancement. Discussion and conclusion CMR imaging identified SHD in around 20% of patients with normal ECG and echocardiogram. Among patients with identified SHD, ischemic cardiopathy was the most common finding, differently from the largest study that showed myocarditis as the main diagnosis. This may be associated to higher age in the SHD group. In conclusion, CMR allowed diagnosis of clinically relevant SHD even when echocardiography excluded it. Funding Acknowledgement Type of funding sources: None.

Peripheral microvascular function is linked to cardiac involvement on CMR in systemic sclerosis-related pulmonary arterial hypertension patients

Abstract Background Systemic sclerosis (SSc) is characterized by vasculopathy, inflammation and fibrosis, and carries one of the worst prognosis in patients who also develop pulmonary arterial hypertension (PAH). Although PAH is a known prognosticator, SSc-PAH patients demonstrate disproportionately high morbidity and mortality, presumably due to cardiac involvement. Purpose To determine the pathophysiology of cardiac involvement in SSc, cardiovascular magnetic resonance (CMR) measures of perfusion, inflammation and fibrosis were compared between SSc-PAH and idiopathic PAH (IPAH) patients. In addition, the correlation between myocardial involvement on CMR and known markers of peripheral microvascular function was assessed. Methods Consecutive patients with SSc-PAH and IPAH of similar age and gender, consecutively underwent CMR imaging, and nailfold capillaroscopy (NC) with post-occlusive reactivity hyperaemia-test (PORH-test). CMR imaging included T2 mapping (inflammation), pre- and postcontrast T1 mapping to calculate the extracellular volume fraction (ECV, fibrosis), and adenosine-stress perfusion imaging to measure the relative myocardial upslope (microvascular perfusion), all measurements were performed on the left ventricle. These CMR markers were related to peripheral microvascular function by NC and PORH-test. Results Twenty SSc-PAH patients (71 [62–77] years, 14% male) and 5 IPAH patients (69 [47–77] years, 20% male) were included. SSc-PAH patients had higher ECV and T2 values than IPAH patients. NC showed lower average capillary density and reduced recruitment of capillaries after PORH in SSc-PAH patients, corresponding to impaired microvascular structure and function. Both higher ECV and T2 values correlated with lower average capillary density (r=−0.454 and −0.583, respectively, p&amp;lt;0.05 for both). Additionally, higher T2 values and lower relative myocardial upslope correlated with worse peripheral microvascular function measured by PORH-test (r=−0.471 and r=0.421, respectively, p&amp;lt;0.05 for both). Conclusion SSc-PAH patients showed higher markers of cardiac fibrosis and inflammation, compared to IPAH patients. These markers correlated well with worse peripheral microvascular function, suggesting that SSc-driven inflammation and vasculopathy concurrently affect peripheral microcirculation and the heart. This may have important therapeutic implications, for which future studies are warranted evaluating the role of anti-inflammatory/anti-fibrotic therapy. Funding Acknowledgement Type of funding sources: None.

Towards automatic classification of cardiovascular magnetic resonance Task Force Criteria for diagnosis of arrhythmogenic right ventricular cardiomyopathy

BackgroundArrhythmogenic right ventricular cardiomyopathy (ARVC) is diagnosed according to the Task Force Criteria (TFC) in which cardiovascular magnetic resonance (CMR) imaging plays an important role. Our study aims to apply an automatic deep learning-based segmentation for right and left ventricular CMR assessment and evaluate this approach for classification of the CMR TFC.MethodsWe included 227 subjects suspected of ARVC who underwent CMR. Subjects were classified into (1) ARVC patients fulfilling TFC; (2) at-risk family members; and (3) controls. To perform automatic segmentation, a Bayesian Dilated Residual Neural Network was trained and tested. Performance of automatic versus manual segmentation was assessed using Dice-coefficient and Hausdorff distance. Since automatic segmentation is most challenging in basal slices, manual correction of the automatic segmentation in the most basal slice was simulated (automatic−basal). CMR TFC calculated using manual and automatic−basal segmentation were compared using Cohen’s Kappa (κ).ResultsAutomatic segmentation was trained on CMRs of 70 subjects (39.6 ± 18.1 years, 47% female) and tested on 157 subjects (36.9 ± 17.6 years, 59% female). Dice-coefficient and Hausdorff distance showed good agreement between manual and automatic segmentations (≥ 0.89 and ≤ 10.6 mm, respectively) which further improved after simulated correction of the most basal slice (≥ 0.92 and ≤ 9.2 mm, p < 0.001). Pearson correlation of volumetric and functional CMR measurements was good to excellent (automatic (r = 0.78–0.99, p < 0.001) and automatic−basal (r = 0.88–0.99, p < 0.001) measurements). CMR TFC classification using automatic−basal segmentations was comparable to manual segmentations (κ 0.98 ± 0.02) with comparable diagnostic performance.ConclusionsCombining automatic segmentation of CMRs with correction of the most basal slice results in accurate CMR TFC classification of subjects suspected of ARVC.Graphical abstract

405 Automated Assessment Of Global Left Ventricular Function And Mass By Cine Computed Tomography Angiography

Introduction: Cine Cardiovascular Computed Tomography Angiography (CTA) provides exceptional spatial resolution for the assessment of left ventricular (LV) contractile function. However, reliable measurement of LV volume and myocardial mass (LVM) over different cardiac phases imposes a major burden for manual delineation. We propose an artificial intelligent (AI) system to automatically segment the LV and LVM from Cine CTA images and compare the results with Cine Cardiovascular Magnetic Resonance (CMR) measurements.

Combined Analysis of Myocardial Deformation and Oxygenation Detects Inducible Ischemia Unmasked by Breathing Maneuvers in Chronic Coronary Syndrome.

IntroductionIn patients with chronic coronary syndromes, hyperventilation followed by apnea has been shown to unmask myocardium susceptible to inducible deoxygenation. The aim of this study was to assess whether such a provoked response is co-localized with myocardial dysfunction.MethodsA group of twenty-six CAD patients with a defined stenosis (quantitative coronary angiography > 50%) underwent a cardiovascular magnetic resonance (CMR) exam prior to revascularization. Healthy volunteers older than 50 years served as controls (n = 12). Participants hyperventilated for 60s followed by brief apnea. Oxygenation-sensitive images were analyzed for changes in myocardial oxygenation and strain.ResultsIn healthy subjects, hyperventilation resulted in global myocardial deoxygenation (-10.2 ± 8.2%, p < 0.001) and augmented peak circumferential systolic strain (-3.3 ± 1.6%, p < 0.001). At the end of apnea, myocardial signal intensity had increased (+9.1 ± 5.3%, p < 0.001) and strain had normalized to baseline. CAD patients had a similar global oxygenation response to hyperventilation (−5.8 ± 9.6%, p = 0.085) but showed no change in peak strain from their resting state (-1.3 ± 1.6%), which was significantly attenuated in comparison the strain response observed in controls (p = 0.008). With apnea, the CAD patients showed an attenuated global oxygenation response to apnea compared to controls (+2.7 ± 6.2%, p < 0.001). This was accompanied by a significant depression of peak strain (3.0 ± 1.7%, p < 0.001), which also differed from the control response (p = 0.025). Regional analysis demonstrated that post-stenotic myocardium was most susceptible to de-oxygenation and systolic strain abnormalities during respiratory maneuvers. CMR measures at rest were unable to discriminate post-stenotic territory (p > 0.05), yet this was significant for both myocardial oxygenation [area under the curve (AUC): 0.88, p > 0.001] and peak strain (AUC: 0.73, p = 0.023) measured with apnea. A combined analysis of myocardial oxygenation and peak strain resulted in an incrementally higher AUC of 0.91, p < 0.001 than strain alone.ConclusionIn myocardium of patients with chronic coronary syndromes and primarily intermediate coronary stenoses, cine oxygenation-sensitive CMR can identify an impaired vascular and functional response to a vasoactive breathing maneuver stimulus indicative of inducible ischemia.

Sex-based differences in left ventricular remodeling in patients with chronic aortic regurgitation: a multi-modality study

BackgroundSignificant aortic regurgitation (AR) leads to left ventricular (LV) remodeling; however, little data exist regarding sex-based differences in LV remodeling in this setting. We sought to compare LV remodeling and AR severity, assessed by echocardiography and cardiovascular magnetic resonance (CMR), to discern sex-based differences.MethodsPatients with ≥ moderate chronic AR by echocardiography who underwent CMR within 90 days between December 2005 and October 2015 were included. Nonlinear regression models were built to assess the effect of AR regurgitant fraction (RF) on LV remodeling. A generalized linear model and Bland Altman analyses were constructed to evaluate differences between CMR and echocardiography. Referral for surgical intervention based on symptoms and LV remodeling was evaluated.ResultsOf the 243 patients (48.3 ± 16.6 years, 58 (24%) female), 119 (49%) underwent surgical intervention with a primary indication of severe AR, 97 (82%) men, 22 (18%) women. Significant sex differences in LV remodeling emerged on CMR. Women demonstrated significantly smaller LV end-diastolic volume index (LVEDVI) (96.8 ml/m2 vs 125.6 ml/m2, p < 0.001), LV end-systolic volume index (LVESVI) (41.1 vs 54.5 ml/m2, p < 0.001), blunted LV dilation in the setting of increasing AR severity (LVEDVI p value < 0.001, LVESVI p value 0.011), and LV length indexed (8.32 vs 9.69 cm, p < 0.001). On Bland Altman analysis, a significant interaction with sex and LV diameters was evident, demonstrating a significant increase in the difference between CMR and echocardiography measurements as the LV enlarged in women: LVEDVI (p = 0.006), LVESVI (p < 0.001), such that echocardiographic measurements increasingly underestimated LV diameters in women as the LV enlarged. LV length was higher for males with a linear effect from RF (p < 0.001), with LV length increasing at a higher rate with increasing RF for males compared to females (two-way interaction with sex p = 0.005). Sphericity volume index was higher for men after adjusting for a relative wall thickness (p = 0.033).ConclusionsCMR assessment of chronic AR revealed significant sex differences in LV remodeling and significant echocardiographic underestimation of LV dilation, particularly in women. Defining optimal sex-based CMR thresholds for surgical referral should be further developed.Trial registration: NA.

Assessment of right ventricular size and function from cardiovascular magnetic resonance images using artificial intelligence

BackgroundTheoretically, artificial intelligence can provide an accurate automatic solution to measure right ventricular (RV) ejection fraction (RVEF) from cardiovascular magnetic resonance (CMR) images, despite the complex RV geometry. However, in our recent study, commercially available deep learning (DL) algorithms for RVEF quantification performed poorly in some patients. The current study was designed to test the hypothesis that quantification of RV function could be improved in these patients by using more diverse CMR datasets in addition to domain-specific quantitative performance evaluation metrics during the cross-validation phase of DL algorithm development.MethodsWe identified 100 patients from our prior study who had the largest differences between manually measured and automated RVEF values. Automated RVEF measurements were performed using the original version of the algorithm (DL1), an updated version (DL2) developed from a dataset that included a wider range of RV pathology and validated using multiple domain-specific quantitative performance evaluation metrics, and conventional methodology performed by a core laboratory (CORE). Each of the DL-RVEF approaches was compared against CORE-RVEF reference values using linear regression and Bland–Altman analyses. Additionally, RVEF values were classified into 3 categories: ≤ 35%, 35–50%, and ≥ 50%. Agreement between RVEF classifications made by the DL approaches and the CORE measurements was tested.ResultsCORE-RVEF and DL-RVEFs were obtained in all patients (feasibility of 100%). DL2-RVEF correlated with CORE-RVEF better than DL1-RVEF (r = 0.87 vs. r = 0.42), with narrower limits of agreement. As a result, DL2 algorithm also showed increasing accuracy from 0.53 to 0.80 for categorizing RV function.ConclusionsThe use of a new DL algorithm cross-validated on a dataset with a wide range of RV pathology using multiple domain-specific metrics resulted in a considerable improvement in the accuracy of automated RVEF measurements. This improvement was demonstrated in patients whose images were the most challenging and resulted in the largest RVEF errors. These findings underscore the critical importance of this strategy in the development of DL approaches for automated CMR measurements.

Impact of ferumoxytol vs gadolinium on 4D flow cardiovascular magnetic resonance measurements in small children with congenital heart disease

BackgroundCardiovascular magnetic resonance (CMR) allows for time-resolved three-dimensional phase-contrast (4D Flow) analysis of congenital heart disease (CHD). Higher spatial resolution in small infants requires thinner slices, which can degrade the signal. Particularly in infants, the choice of contrast agent (ferumoxytol vs. gadolinium) may influence 4D Flow CMR accuracy. Thus, we investigated the accuracy of 4D Flow CMR measurements compared to gold standard 2D flow phase contrast (PC) measurements in ferumoxytol vs. gadolinium-enhanced CMR of small CHD patients with shunt lesions.MethodsThis was a retrospective study consisting of CMR studies from complex CHD patients less than 20 kg who had ferumoxytol or gadolinium-enhanced 4D Flow and standard two-dimensional phase contrast (2D-PC) flow collected. 4D Flow clinical software (Arterys) was used to measure flow in great vessels, systemic veins, and pulmonary veins. 4D Flow accuracy was defined as percent difference or correlation against conventional measurements (2D-PC) from the same vessels. Subgroup analysis was performed on two-ventricular vs single-ventricular CHD, arterial vs venous flow, as well as low flows (defined as < 1.5 L/min) in 1V CHD.ResultsTwenty-one ferumoxytol-enhanced and 23 gadolinium-enhanced CMR studies were included, with no difference in age (2.1 ± 1.6 vs. 2.3 ± 1.9 years, p = 0.70), patient body surface area (0.50 ± 0.2 vs. 0.52 ± 0.2 m2, p = 0.67), or vessel diameter (11.4 ± 5.2 vs. 12.4 ± 5.6 mm, p = 0.22). Ten CMR studies with single ventricular CHD were included. Overall, ferumoxytol-enhanced 4D flow CMR measurements demonstrated less percent difference to 2D-PC when compared to gadolinium-enhanced 4D Flow CMR studies. In subgroup analyses of arterial vs. venous flows (high velocity vs. low velocity) and low flow in single ventricle CHD, ferumoxytol-enhanced 4D Flow CMR measurements had stronger correlation to 2D-PC CMR. The contrast-to-noise ratio (CNR) in ferumoxytol-enhanced studies was higher than the CNR in gadolinium-enhanced studies.ConclusionsFerumoxytol-enhanced 4D Flow CMR has improved accuracy when compared to gadolinium 4D Flow CMR, particularly for infants with small vessels in CHD.