Non-invasive Cardiovascular Magnetic Resonance Research Articles

Increased Aortic Stiffness With Acute Exercise in Heart Failure: Assessment by Cardiovascular Magnetic Resonance

This study aimed to investigate the acute changes in proximal aortic distensibility, a measure of aortic stiffness, induced by acute exercise in participants with and without heart failure (HF). Participants with HF (n = 24) and without HF (n = 26) underwent cardiovascular magnetic resonance (CMR) (1.5 T) imaging at rest and after submaximal supine bicycle ergometry. The participants were further categorized into HF with reduced ejection fraction (HFrEF) (n = 14) and HF with preserved ejection fraction (n = 10) based on the left ventricular ejection fraction. At rest and immediately after exercise, cine CMR images of the cross-sectional ascending and descending aorta at the pulmonary artery bifurcation level were obtained to determine aortic distensibility (AoD), with lower AoD indicating greater aortic stiffness. Differences in means of values at rest and before and after exercise were compared using the nonparametric Wilcoxon sign test. There was no significant difference in AoD at rest between subjects with HF and controls. However, immediately after exercise, participants with HF but not controls exhibited a significant reduction in AoD, indicating higher aortic stiffness related to exercise (median [interquartile range] for the ascending aorta: 3.16 (1.26) × 10-3 mm Hg-1 to 2.39 (1.57) × 10-3 mm Hg-1 and the descending aorta: 4.19 (2.58) × 10-3 mm Hg-1 to 2.96 (1.79) × 10-3 mm Hg-1) (both p = 0.023). This decrease was particularly observed in participants with HFrEF but not in those with HF with preserved ejection fraction. Exercise-induced aortic stiffness, detectable by noninvasive CMR, may contribute to unfavorable ventricular-vascular interactions during exercise in participants with HF, especially HFrEF.

Real-time cardiovascular magnetic resonance imaging for non-invasive characterisation of heart failure with preserved ejection fraction: final outcomes of the HFpEF stress trial

BackgroundThe diagnosis of heart failure with preserved ejection fraction (HFpEF) remains challenging. Recently, the HFpEF Stress Trial demonstrated feasibility and accuracy of non-invasive cardiovascular magnetic resonance (CMR) real-time (RT) exercise-stress atrial function imaging for early identification of HFpEF. However, no outcome data have yet been presented.MethodsThe HFpEF Stress Trial (DZHK-17) prospectively recruited 75 patients with dyspnea on exertion and echocardiographic preserved EF and signs of diastolic dysfunction (E/eʹ > 8). 68 patients entered the final study cohort and were characterized as HFpEF (n = 34) or non-cardiac dyspnea (n = 34) according to pulmonary capillary wedge pressure (HFpEF: PCWP rest: ≥ 15 mmHg stress: ≥ 25 mmHg). These patients were contacted by telephone and hospital charts were reviewed. The clinical endpoint was cardiovascular events (CVE).ResultsFollow-up was performed after 48 months; 1 patient was lost to follow-up. HFpEF patients were more frequently compared to non-cardiac dyspnea (15 vs. 8, p = 0.059). Hospitalised patients during follow-up had higher H2FPEF scores (5 vs. 3, p < 0.001), and impaired left atrial (LA) function at rest (p ≤ 0.002) and stress (p ≤ 0.006). Impairment of CMR-derived atrial function parameters at rest and during exercise-stress (p ≤ 0.003) was associated with increased likelihood for CVE. CMR-Feature Tracking LA Es/Ee (p = 0.016/0.017) and RT-CMR derived LA long axis strain (p = 0.003) were predictors of CVE independent of the presence of atrial fibrillation.ConclusionsLeft atrial function emerged as the strongest predictor for 4-year outcome in the HFpEF Stress Trial. A combination of rest and exercise-stress LA function quantification allows accurate diagnostic and prognostic stratification in HFpEF.Clinicaltrials.gov: NCT03260621.Graphical abstract

Non-invasive cardiovascular magnetic resonance assessment of pressure recovery distance after aortic valve stenosis

BackgroundDecisions in the management of aortic stenosis are based on the peak pressure drop, captured by Doppler echocardiography, whereas gold standard catheterization measurements assess the net pressure drop but are limited by associated risks. The relationship between these two measurements, peak and net pressure drop, is dictated by the pressure recovery along the ascending aorta which is mainly caused by turbulence energy dissipation. Currently, pressure recovery is considered to occur within the first 40–50 mm distally from the aortic valve, albeit there is inconsistency across interventionist centers on where/how to position the catheter to capture the net pressure drop. MethodsWe developed a non-invasive method to assess the pressure recovery distance based on blood flow momentum via 4D Flow cardiovascular magnetic resonance (CMR). Multi-center acquisitions included physical flow phantoms with different stenotic valve configurations to validate this method, first against reference measurements and then against turbulent energy dissipation (respectively n = 8 and n = 28 acquisitions) and to investigate the relationship between peak and net pressure drops. Finally, we explored the potential errors of cardiac catheterisation pressure recordings as a result of neglecting the pressure recovery distance in a clinical bicuspid aortic valve (BAV) cohort of n = 32 patients. ResultsIn-vitro assessment of pressure recovery distance based on flow momentum achieved an average error of 1.8 ± 8.4 mm when compared to reference pressure sensors in the first phantom workbench. The momentum pressure recovery distance and the turbulent energy dissipation distance showed no statistical difference (mean difference of 2.8 ± 5.4 mm, R2 = 0.93) in the second phantom workbench. A linear correlation was observed between peak and net pressure drops, however, with strong dependences on the valvular morphology. Finally, in the BAV cohort the pressure recovery distance was 78.8 ± 34.3 mm from vena contracta, which is significantly longer than currently accepted in clinical practise (40–50 mm), and 37.5% of patients displayed a pressure recovery distance beyond the end of the ascending aorta. ConclusionThe non-invasive assessment of the distance to pressure recovery is possible by tracking momentum via 4D Flow CMR. Recovery is not always complete at the ascending aorta, and catheterised recordings will overestimate the net pressure drop in those situations. There is a need to re-evaluate the methods that characterise the haemodynamic burden caused by aortic stenosis as currently clinically accepted pressure recovery distance is an underestimation.

Influence of right ventricular pressure and volume overload on right and left ventricular diastolic function

BackgroundVentricular interdependence may account for altered ventricular mechanics in congenital heart disease. The present study aimed to identify differences in load-dependent right ventricular (RV)–left ventricular (LV) interactions in porcine models of pulmonary stenosis (PS) and pulmonary insufficiency (PI) by invasive admittance-derived hemodynamics in conjunction with noninvasive cardiovascular magnetic resonance (CMR). MethodsSeventeen pigs were used in the study (7 with PS, 7 with PI, and 3 controls). Progressive PS was created by tightening a Teflon tape around the pulmonary artery, and PI was created by excising 2 leaflets of the pulmonary valve. Admittance catheterization data were obtained for the RV and LV at 10 to 12 weeks after model creation, with the animal ventilated under temporary diaphragm paralysis. CMR was performed in all animals immediately prior to pressure–volume catheterization. ResultsIn the PS group, RV contractility was increased, manifested by increased end-systolic elastance (mean difference, 1.29 mm Hg/mL; 95% confidence interval [CI], 0.57-2.00 mm Hg/mL). However, in the PI group, no significant changes were observed in RV systolic function despite significant changes in RV diastolic function. In the PS group, LV end-systolic volume was significantly lower compared with controls (mean difference, 25.1 mL; 95% CI, -40.5 to -90.7 mL), whereas in the PI group, the LV showed diastolic dysfunction, demonstrated by an elevated isovolumic relaxation constant and ventricular stiffness (mean difference, 0.03 mL−1; 95% CI, -0.02 to 0.09 mL−1). ConclusionsThe LV exhibits systolic dysfunction and noncompliance with PI. PS is associated with preserved LV systolic function and evidence of some LV diastolic dysfunction. Interventricular interactions influence LV filling and likely account for differential effects of RV pressure and volume overload on LV function.

A 25-Year-Old Man with Refractory Schizophrenia and Clozapine-Induced Myocarditis Diagnosed by Non-Invasive Cardiovascular Magnetic Resonance

Patient: Male, 25-year-oldFinal Diagnosis: Clozapine-induced myocarditisSymptoms: Elevated troponin • fever • leukocytosis • somnolence • tachycardiaMedication: —Clinical Procedure: Cardiovascular magnetic resonance • electrocardiogram • transthoracic echocardiogramSpecialty: Cardiology • General and Internal MedicineObjective:Rare diseaseBackground:Clozapine, a second-generation antipsychotic, is often prescribed for refractory schizophrenia; however, it can cause life-threatening adverse events including agranulocytosis and myocarditis. Making the diagnosis of clozapine-induced myocarditis can be challenging given the non-specific presentation as well as risk involved in obtaining an endomyocardial biopsy. As clozapine-induced myocarditis carries a mortality risk of up to 30%, timely recognition, diagnosis, and management are vital. This report presents a case of clozapine-induced myocarditis in a 25-year-old man with refractory schizophrenia who was diagnosed using non-invasive imaging with cardiovascular magnetic resonance (CMR).Case Report:A 25-year-old man with refractory schizophrenia was admitted with severe psychotic symptoms and started on a rapid titration of clozapine. During his hospitalization he developed somnolence, fever, and tachycardia with leukocytosis, elevated inflammatory markers, and cardiac biomarkers concerning for clozapine-induced myocarditis. Alternative etiologies were ruled out and CMR was used to confirm the diagnosis. The patient’s symptoms resolved following discontinuation of clozapine and initiation of supportive therapies.Conclusions:Clozapine-induced myocarditis is challenging to diagnose due to a lack of consensus on diagnostic criteria, reliance on voluntary reporting, and non-specific presentation. This report highlights that myocarditis can be associated with clozapine pharmacotherapy in patients with schizophrenia and demonstrates the value of diagnosis using non-invasive CMR. Additional studies are needed to understand the mechanism of clozapine-induced myocarditis and how clozapine titration may affect risk.

Diagnostic and prognostic significance of cardiovascular magnetic resonance native myocardial T1 mapping in patients with pulmonary hypertension

BackgroundNative T1 may be a sensitive, contrast-free, non-invasive cardiovascular magnetic resonance (CMR) marker of myocardial tissue changes in patients with pulmonary artery hypertension. However, the diagnostic and prognostic value of native T1 mapping in this patient group has not been fully explored. The aim of this work was to determine whether elevation of native T1 in myocardial tissue in pulmonary hypertension: (a) varies according to pulmonary hypertension subtype; (b) has prognostic value and (c) is associated with ventricular function and interaction.MethodsData were retrospectively collected from a total of 490 consecutive patients during their clinical 1.5 T CMR assessment at a pulmonary hypertension referral centre in 2015. Three hundred sixty-nine patients had pulmonary hypertension [58 ± 15 years; 66% female], an additional 39 had pulmonary hypertension due to left heart disease [68 ± 13 years; 60% female], 82 patients did not have pulmonary hypertension [55 ± 18; 68% female]. Twenty five healthy subjects were also recruited [58 ±4 years); 51% female]. T1 mapping was performed with a MOdified Look-Locker Inversion Recovery (MOLLI) sequence. T1 prognostic value in patients with pulmonary arterial hypertension was assessed using multivariate Cox proportional hazards regression analysis.ResultsPatients with pulmonary artery hypertension had elevated T1 in the right ventricular (RV) insertion point (pulmonary hypertension patients: T1 = 1060 ± 90 ms; No pulmonary hypertension patients: T1 = 1020 ± 80 ms p < 0.001; healthy subjects T1 = 940 ± 50 ms p < 0.001) with no significant difference between the major pulmonary hypertension subtypes. The RV insertion point was the most successful T1 region for discriminating patients with pulmonary hypertension from healthy subjects (area under the curve = 0.863) however it could not accurately discriminate between patients with and without pulmonary hypertension (area under the curve = 0.654). T1 metrics did not contribute to prediction of overall mortality (septal: p = 0.552; RV insertion point: p = 0.688; left ventricular free wall: p = 0.258). Systolic interventricular septal angle was a significant predictor of T1 in patients with pulmonary hypertension (p < 0.001).ConclusionsElevated myocardial native T1 was found to a similar extent in pulmonary hypertension patient subgroups and is independently associated with increased interventricular septal angle. Native T1 mapping may not be of additive value in the diagnostic or prognostic evaluation of patients with pulmonary artery hypertension.

Non-invasive methods for estimating mPAP in COPD using cardiovascular magnetic resonance imaging

PurposePulmonary hypertension (PH) is associated with a poor outcome in chronic obstructive pulmonary disease (COPD) and is diagnosed invasively. We aimed to assess the diagnostic accuracy and prognostic value of non-invasive cardiovascular magnetic resonance (CMR) models.MethodsPatients with COPD and suspected PH, who underwent CMR and right heart catheter (RHC) were identified. Three candidate models were assessed: 1, CMR-RV model, based on right ventricular (RV) mass and interventricular septal angle; 2, CMR PA/RV includes RV mass, septal angle and pulmonary artery (PA) measurements; 3, the Alpha index, based on RV ejection fraction and PA size.ResultsOf 102 COPD patients, 87 had PH. The CMR-PA/RV model had the strongest diagnostic accuracy (sensitivity 92%, specificity 80%, positive predictive value 96% and negative predictive value 63%, AUC 0.93, p<0.0001). Splitting RHC-mPAP, CMR-RV and CMR-PA/RV models by 35mmHg gave a significant difference in survival, with log-rank chi-squared 5.03, 5.47 and 7.10. RV mass and PA relative area change were the independent predictors of mortality at multivariate Cox regression (p=0.002 and 0.030).ConclusionCMR provides diagnostic and prognostic information in PH-COPD. The CMR-PA/RV model is useful for diagnosis, the RV mass index and PA relative area change are useful to assess prognosis.Key Points• Pulmonary hypertension is a marker of poor outcome in COPD.• MRI can predict invasively measured mean pulmonary artery pressure.• Cardiac MRI allows for estimation of survival in COPD.• Cardiac MRI may be useful for follow up or future trials.• MRI is potentially useful to assess pulmonary hypertension in patients with COPD.

Diagnostic value of global myocardial perfusion reserve assessment based on coronary sinus flow measurements using cardiovascular magnetic resonance in addition to myocardial stress perfusion imaging.

Myocardial perfusion reserve (MPR) is defined as the maximal possible increase in myocardial blood flow (MBF) above baseline conditions. Global MBF can be measured non-invasively by means of coronary sinus flow velocity encoded cine (VENC) cardiovascular magnetic resonance (CMR). We aimed to explore the relationship between global MBF/MPR and the extent and severity of coronary artery disease (CAD) in patients referred for CAD work-up by adenosine-stress CMR. Fifty-eight patients with suspected obstructive CAD underwent both adenosine-stress CMR and invasive coronary angiography. In addition to standard cine- and late gadolinium enhancement (LGE)-imaging, first-pass myocardial perfusion imaging (MPI) and coronary sinus flow measurements (VENC) were performed at rest and during peak stress (after 140 µg/kg/min adenosine), respectively. Nineteen young patients with a very low CAD pre-test probability and normal adenosine-stress CMR formed the control group. Fifty-nine percent (n = 34) of the study group showed segmental, adenosine-induced myocardial perfusion defects compared to none of the control group (P < 0.001). Global MPR was lower in the study group compared to the control group: 2.3 (1.5-3.1) vs. 3.1 (2.0-4.3), P = 0.016. The SYNTAX score was higher in the study group patients with an impaired MPR (<2) compared to those with a preserved MPR (3.0 vs. 16.0, P = 0.01)-mainly due to higher prevalence of proximal epicardial stenoses (60% vs. 27%, P = 0.02) and multi-vessel disease (56% vs. 24%, P = 0.017). The diagnostic yield of stress CMR for the diagnosis of CAD (>50% stenosis) increased from 65to 88% when global MPR assessment was considered in addition to MPI (P = 0.025). Global MBF and MPR values correlate with the anatomical extent and complexity of CAD and increase the diagnostic yield of non-invasive stress CMR in the work-up of CAD. CMR-based MBF and MPR measurements may play a future role in the evaluation of the total ischaemic burden-particularly in patients with multi-vessel disease.

Pericardial Effusion Is a Marker of Increased Mortality in Thalassemia Major Patients

Introduction. In different types of not-hematological diseases the presence of a small pericardial effusion (PE) was associated with worse survival even after adjustment for patient characteristics, suggesting that it is a marker of underlying disease.In thalassemia major (TM) pericardial effusion was shown to be one of the manifestations of heart disease but its potential prognostic importance has never been investigated in the modern era. Cardiovascular Magnetic Resonance (CMR) by cine SSFP sequences was demonstrated to be extremely sensitive to even a small amount of PE.This is the first prospective study evaluating if the presence of pericardial effusion is associated with increased mortality in TM.Methods. 1259 patients (648 females, mean age 31.02 ± 8.64 years) enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) were prospectively followed from their first Magnetic Resonance Imaging (MRI) scan. CMR was used to quantify myocardial iron (MIO) overload by a multislice multiecho T2* approach and to assess biventricular function parameters and to detect PE by cine SSFP sequences.Results. PE was present in 25 (2.0%) patients.Patients with and without PE were comparable for age and ratio of men/women. At the baseline, the percentage of patients with MIO (global heart T2* value < 20 ms) was comparable between patients with and without PE (12.0 % vs 28.7%; P=0.074) and left ventricular and right ventricular ejection fractions were not significantly different between the two groups.Mean follow-up (FU) time was 44.55 ± 20.35 months and there were 15 deaths.Mortality was greater for patients with PE compared to those without an effusion (8.0% vs 1.1%, P=0.034).PE was a significant predictive factor for death (hazard ratio-HR=12.64, 95%CI=2.78-57.42, P=0.001). PE remained a significant prognosticator for death also in a multivariate model including MIO ms (PE: HR=17.36, 95%CI=3.65-82.62, P<0.0001and global heart T2* < 20 ms: HR=3.07, 95%CI=1.07-8.75, P=0.036).Conclusions. PE is quite rare in TM patients and it is not related to myocardial iron overload. An important role in the development of PE could be played by the 'iron-induced’ pericardial siderosis but, due to the limitations of the current non-invasive CMR techniques, we were not able to address this issue.PE was found to be a strong predictor for death, independently by the presence of myocardial iron overload. The non-invasive diagnosis of pericardial effusion is important for a more complete definition of the cardiac involvement of TM patients. The increased risk of death associated with PE may be used along with other clinical characteristics when estimating a patient’s prognosis and monitoring. DisclosuresPepe:Chiesi: Speakers Bureau; ApoPharma Inc.: Speakers Bureau; Novartis: Speakers Bureau.

Radiology and pathology correlation in common infiltrative cardiomyopathies

Infiltrative cardiomyopathies generally pose a diagnostic dilemma as current diagnostic tools are imprecise. Invasive endomyocardial biopsy is considered as the gold standard however it has some limitations. Recently cardiovascular magnetic resonance (CMR) is emerging as an excellent technique in diagnosing infiltrative cardiomyopathies and is increasingly being used. Characteristic pathologic and radiologic findings in most common infiltrative cardiomyopathies (amyloid, sarcoid and Fabry's) are discussed and correlated with relative CMR and histologic examples. There is fairly good correlation between the non-invasive radiologic and the invasive histologic findings in common infiltrative cardiomyopathies. Non-invasive CMR with its high sensitivity and specificity has an excellent role in establishing the diagnosis and improving the prognosis of common infiltrative cardiomyopathies.

Diagnostic synergy of non-invasive cardiovascular magnetic resonance and invasive endomyocardial biopsy in troponin-positive patients without coronary artery disease

Diagnostic synergy of non-invasive cardiovascular magnetic resonance and invasive endomyocardial biopsy in troponin-positive patients without coronary artery disease

Diagnostic synergy of non-invasive cardiovascular magnetic resonance and invasive endomyocardial biopsy in troponin-positive patients without coronary artery disease

Only few data are available regarding a direct comparison of both non-invasive CMR and invasive EMB with respect to conformity of procedure-derived diagnoses in the same patients. The aim of this study was to elucidate the diagnostic performance of non-invasive cardiovascular magnetic resonance imaging (CMR) and endomyocardial biopsy (EMB) in patients with troponin-I (TnI) positive acute chest pain in the absence of significant coronary artery disease (CAD). One thousand one hundred and seventy-four consecutive patients who were admitted with TnI-positive acute chest pain between March 2004 and July 2007 underwent coronary angiography. In 1012 patients (86%), significant CAD (stenosis >50%) was detected as underlying reason for the acute chest pain. In 82 out of the remaining 162 patients without significant CAD, further workup was performed including both CMR and EMB. Cardiovascular magnetic resonance imaging alone enabled a diagnosis in 66/82 (80%) and EMB alone in 72/82 (88%) patients (P = 0.31). Myocarditis was the most frequent diagnosis by both CMR and EMB in this cohort and was detected with a higher frequency by EMB (58 vs. 81%; P < 0.001). With the combined approach comprising CMR and EMB, a final diagnosis could be established applying the 'Believe-The-Positive-Rule' in 78/82 patients (95%). This combined approach turned out to yield more diagnoses than either CMR (P < 0.001) or EMB (P = 0.03) as single techniques, respectively. Comparison of diagnostic CMR procedures with the corresponding diagnostic EMBs demonstrated a substantial match of diagnoses (kappa = 0.70). Cardiovascular magnetic resonance imaging and EMB have good diagnostic performances as single techniques in patients with TnI-positive acute chest pain in the absence of CAD. The combined application of CMR and EMB yields a considerable diagnostic synergy by overcoming some limitations of CMR and EMB as individually applied techniques.

Stellenwert der kardiovaskulären Magnetresonanztomographie in der Diagnostik der koronaren Herzerkrankung

Currently, the main focus of non-invasive cardiovascular magnetic resonance imaging for diagnosis of coronary artery disease is twofold: first, functional imaging with assessment of the hemodynamic consequences of obstructive coronary artery disease and second, anatomical imaging with direct visualization of the coronary arterial tree. This manuscript will provide an overview of the cardiovascular magnetic resonance imaging modules used to detect coronary artery disease and will update the reader on its current clinical indications with a special focus on functional versus anatomical imaging.

Age and sex distribution of subclinical aortic atherosclerosis: a magnetic resonance imaging examination of the Framingham Heart Study.

Autopsy data demonstrate a correlation between subclinical aortic atherosclerosis and cardiovascular disease. Therefore, noninvasive cardiovascular magnetic resonance (CMR) of subclinical atherosclerosis may provide a novel measure of cardiovascular risk, but it has not been applied to an asymptomatic population-based cohort to establish age- and sex-specific normative data. Participants in the Framingham Heart Study offspring cohort who were free of clinically apparent coronary disease were randomly sampled from strata of sex, quartiles of age, and quintiles of Framingham Coronary Risk Score. Subjects (n=318, aged 60+/-9 years, range 36 to 78 years, 51% women) underwent ECG-gated T2-weighted black-blood thoracoabdominal aortic CMR scanning. CMR evidence of aortic atherosclerosis was noted in 38% of the women and 41% of the men. Plaque prevalence and all measures of plaque burden increased with age group and were greater in the abdomen than in the thorax for both sexes and across all age groups. In addition, the Framingham Coronary Risk Score was significantly correlated with all plaque prevalence and burden measures for women but only for men after age adjustment. These noninvasive CMR data extend the prior autopsy-based prevalence estimates of subclinical atherosclerosis and may help to lay the foundation for future studies of risk stratification and treatment of affected individuals.