Contrast-enhanced Cardiovascular Magnetic Resonance Imaging Research Articles

Nonischemic or Dual Cardiomyopathy in Patients With Coronary Artery Disease.

Randomized trials in obstructive coronary artery disease (CAD) have largely shown no prognostic benefit from coronary revascularization. Although there are several potential reasons for the lack of benefit, an underexplored possible reason is the presence of coincidental nonischemic cardiomyopathy (NICM). We investigated the prevalence and prognostic significance of NICM in patients with CAD (CAD-NICM). We conducted a registry study of consecutive patients with obstructive CAD on coronary angiography who underwent contrast-enhanced cardiovascular magnetic resonance imaging for the assessment of ventricular function and scar at 4 hospitals from 2004 to 2020. We identified the presence and cause of cardiomyopathy using cardiovascular magnetic resonance imaging and coronary angiography data, blinded to clinical outcomes. The primary outcome was a composite of all-cause death or heart failure hospitalization, and secondary outcomes were all-cause death, heart failure hospitalization, and cardiovascular death. Among 3023 patients (median age, 66 years; 76% men), 18.2% had no cardiomyopathy, 64.8% had ischemic cardiomyopathy (CAD+ICM), 9.3% had CAD+NICM, and 7.7% had dual cardiomyopathy (CAD+dualCM), defined as both ICM and NICM. Thus, 16.9% had CAD+NICM or dualCM. During a median follow-up of 4.8 years (interquartile range, 2.9, 7.6), 1116 patients experienced the primary outcome. In Cox multivariable analysis, CAD+NICM or dualCM was independently associated with a higher risk of the primary outcome compared with CAD+ICM (adjusted hazard ratio, 1.23 [95% CI, 1.06-1.43]; P=0.007) after adjustment for potential confounders. The risks of the secondary outcomes of all-cause death and heart failure hospitalization were also higher with CAD+NICM or dualCM (hazard ratio, 1.21 [95% CI, 1.02-1.43]; P=0.032; and hazard ratio, 1.37 [95% CI, 1.11-1.69]; P=0.003, respectively), whereas the risk of cardiovascular death did not differ from that of CAD+ICM (hazard ratio, 1.15 [95% CI, 0.89-1.48]; P=0.28). In patients with CAD referred for clinical cardiovascular magnetic resonance imaging, NICM or dualCM was identified in 1 of every 6 patients and was associated with worse long-term outcomes compared with ICM. In patients with obstructive CAD, coincidental NICM or dualCM may contribute to the lack of prognostic benefit from coronary revascularization.

Long-term outcomes after coronary artery bypass graft with or without surgical ventricular reconstruction in patients with severe left ventricular dysfunction.

Patients with chronic myocardial infarction (MI) and severe left ventricular (LV) dysfunction have poor clinical outcomes. This study aimed to determine whether coronary artery bypass graft (CABG) with surgical ventricular reconstruction (SVR) leads to further improvement in long-term patient outcomes compared with isolated CABG (I-CABG). From April 2010 to June 2013, 140 consecutive patients with chronic MI and severe LV dysfunction who received contrast-enhanced cardiovascular magnetic resonance imaging (CE-CMR) within 1 month before surgery were enrolled in this study. The cardiovascular events (CVEs) and long-term survival of patients who underwent CABG and SVR were compared with those who met the criteria for SVR but received I-CABG. A total of 140 patients were included in the final analysis, including 70 patients who underwent CABG and SVR and 70 patients who underwent I-CABG. No differences were observed in the baseline characteristics, LV function, and late gadolinium enhancement (LGE) between the two groups. CABG+SVR patients experienced a longer cardiopulmonary bypass (CPB) time (116.0±35.0 vs. 100.2±23.8 minutes, P=0.002) and ventilation time [median (interquartile range): 22.0 (17.0, 37.0) vs. 20.0 (15.0, 24.0) hours, P=0.019] than I-CABG patients. During a mean follow-up of 123.1±12.7 months (range, 102-140 months), the CABG+SVR group had fewer rehospitalizations for congestive heart failure (CHF) (4.3% vs. 19.1%, P=0.007), but no statistical difference in the mortality rate was observed (2.9% vs. 4.4%, P=0.987). The cumulative CVE-free survival rate was significantly higher in CABG+SVR patients (87.0% vs. 67.6%, P=0.007). Our findings indicated that patients with chronic MI and severe LV dysfunction experienced similar perioperative outcomes after CABG+SVR or I-CABG. However, the CABG+SVR group resulted in fewer rehospitalizations for CHF and a higher cumulative CVE-free survival rate.

Cardiac involvement in patients 1 year after recovery from moderate and severe COVID-19 infections.

Some patients suffered persistent cardiac symptoms after hospital discharge following COVID-19 infection, including chest tightness, chest pain, and palpitation. However, the cardiac involvement in these patients remains unknown. The purpose of this study was to investigate the effect of COVID-19 infection on the cardiovascular system after 1 year of recovery in patients hospitalized with persistent cardiac symptoms. In this prospective observational study, a total of 32 patients who had COVID-19 (11 diagnosed as severe COVID-19 and 21 as moderate) with persistent cardiac symptoms after hospital discharge were enrolled. Contrast-enhanced cardiovascular magnetic resonance (CMR) imaging was performed on all patients. Comparisons were made with age- and sex-matched healthy controls (n = 13), and age-, sex- and risk factor-matched controls (n = 21). Further analysis was made between the severe and moderate COVID-19 cohorts. The mean time interval between acute COVID-19 infection and CMR was 462 ± 18 days. Patients recovered from COVID-19 had reduced left ventricular ejection fraction (LVEF) (p = 0.003) and increased extracellular volumes (ECVs) (p = 0.023) compared with healthy controls. Focal late gadolinium enhancement (LGE) was found in 22 (68.8%) patients, mainly distributed linearly in the septal mid-wall or patchily in RV insertion point. The LGE extent in patients with severe COVID-19 was higher than that in patients with moderate COVID-19 (p = 0.009). This 1-year follow-up study revealed that patients with persistent cardiac symptoms, after recovering from COVID-19, had decreased cardiac function and increased ECV compared with healthy controls. Patients with COVID-19 predominately had a LGE pattern of septal mid-wall or RV insertion point. Patients with severe COVID-19 had greater LGE extent than patients with moderate COVID-19.

Prevalence and clinical impact of major incidental findings detected on routine cardiovascular resonance imaging prior to catheter ablation of atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Preprocedural contrast-enhanced cardiovascular magnetic resonance (CMR) or computed tomography (CT) imaging of the left atrium (LA) and pulmonary veins (PVs) is usually employed to facilitate catheter mapping and ablation of atrial fibrillation (AF). Incidental findings (IFs) are common on cardiac imaging prior to AF catheter ablation (AFCA). However, previous studies were of small size and have mainly focused on radiological extracardiac IFs detected on preprocedural CT scan. Purpose To assess the prevalence of major cardiac and extracardiac IFs on routine preprocedural CMR in a large cohort of consecutive patients scheduled for first-time AFCA, and to report its impact on clinical decision-making and management. Methods All consecutive patients who underwent routine preprocedural CMR prior to first-time AFCA between April 2015 and March 2019 were considered for analysis. Main exclusion criteria were referral for repeat AFCA; prior cardiac CT or CMR imaging; and general contraindication to CMR or AFCA. All CMR examinations consisted of survey images with full thoracic coverage, cardiac cine and late-gadolinium enhancement imaging, and three-dimensional contrast-enhanced CMR angiography of the LA/PVs. An IF was defined as major when any newly detected finding either resulted in cancellation of the AFCA procedure or intentional deviation from the standard AFCA protocol. In patients with accessory or anomalous PVs the ablation strategy was individually tailored aiming at isolation of all PVs. Results Two thousand consecutive patients (62±10 years; 59% male) with paroxysmal (48%) or persistent (52%) AF were included. Among the entire study cohort 172 patients (8.6%) had a total of 184 cardiac (75%) and extracardiac (25%) major IFs (Fig. A+B). Preprocedural detection of a major IF resulted in cancellation of the scheduled AFCA procedure in 88 patients (4.4%). Forty-two patients (2.1%) have thereupon never been ablated, 46 patients (2.3%) underwent postponed AFCA after a median time from CMR imaging of 83 (32-213) days. The remaining 84 patients with major IF (4.2%) underwent an individualized approach to AFCA (Fig. A). The most common major IFs were accessory or anomalous PVs in 76 (3.8%), extracardiac abnormalities suspicious of malignancy in 29 (1.5%), and positive stress perfusion imaging in 19 (1.0% overall; 7.2% of 261 tested) patients. In 19 patients (1.0%) preprocedural CMR detected a previously unknown intracardiac thrombus or structural cardiac disease. Conclusion Unexpected major IFs on routine preprocedural CMR affected clinical decision-making and therapeutic management in 8.6% of patients scheduled for first-time AFCA at our institution. Whether preprocedural CMR imaging may improve safety and outcome of AFCA needs to be addressed in future research.

196 Cardiovascular magnetic resonance characterization of myocardial injury in recovered COVID-19 patients with elevated troponins during hospital stay

AimsDespite being a common finding in hospitalized COVID-19 patients, cardiac troponin elevation remains a nonspecific detection of myocardial injury and further in-hospital investigation into the cause of myocardial injury is rarely done. COVID-19 patients with myocardial injury show a significantly higher in-hospital mortality rate compared with those without myocardial injury and among those with myocardial injury, greater degrees of troponin elevation are associated with higher mortality rates. There are still many questions regarding possible cardiovascular sequelae and prognostic significance in these patients. Being able to distinguish between inflammatory and ischaemic causes of myocardial injury cardiovascular magnetic resonance (CMR) is the non-invasive modality of choice to investigate myocardial involvement in these patients. Presented are the preliminary single-centre results from a multicentre study aimed to characterize the prevalence, type and extent of COVID-19-related cardiovascular sequelae using CMR imaging.Methods and resultsIn this single-centre prospective observational cohort study, patients hospitalized with confirmed COVID-19 and at least one value of high sensitivity I troponin (hs-Tnl) >99th percentile during hospitalization were eligible for follow-up contrast-enhanced CMR imaging. Patients with any standard CMR contraindications were excluded. Images were acquired using a standardized myocarditis protocol including late gadolinium enhancement (LGE) and T1 and T2 mapping. Cutoff values of 1015 ms and 50 ms were used for abnormal T1 and T2 measurements, respectively. Of the 21 patients (65 ± 11.85 years) who underwent imaging, 15 (71.4%) were male. The mean follow-up duration from the date of confirmed COVID-19 diagnosis was 169 ± 19 days. The mean left ventricular ejection fraction was 64.1 ± 13.87 and 3 (14.3%) patients had evidence of wall motion abnormalities. LGE was seen in 9/20 (45.0%) patients, reflecting myocardial fibrosis. Increased native T1 signal representing myocardial fibrosis and/or oedema was seen in 9/20 (45.0%) patients. While increased native T2 signal, being more specific for oedema was observed in 3/20 (15.0%) patients. Considering CMR findings, 6 (28.6%) patients showed evidence of previous myocarditis.ConclusionsIn this single centre Italian study of patients hospitalized with COVID-19 and elevated cardiac enzymes, myocarditis-like injury was evident in about a quarter of the patients. Whether these findings will lead to long-term cardiac complications is still to be confirmed.

Myocardial motion-corrected phase-sensitive inversion recovery late gadolinium enhancement in free breathing paediatric patients: a comparison with single-shot coherent gradient echo (“TrueFISP”) phase-sensitive inversion recovery

To investigate the value of motion-corrected (MOCO) phase-sensitive inversion recovery (PSIR) late gadolinium enhancement (LGE) compared with single-shot balanced steady-state gradient echo ("TrueFISP", Siemens) PSIR in free breathing paediatric patients. In this retrospective study, 238 paediatric patients underwent clinical contrast-enhanced cardiovascular magnetic resonance imaging (CMRI). Both the single-shot TrueFISP PSIR and MOCO PSIR sequences were performed on each child. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Two radiologists rated the quality of the images on a scale of 1-5 (1=poor, 5=very good). Bland-Altman, linear regression, and intraclass correlation coefficient were used to compared the extent of LGE of the single-shot TrueFISP PSIR and MOCO PSIR. Imaging artefacts were described and compared. Children ranged in age from 60 days to 17 years with an average age of 8.1±3.8 years. MOCO PSIR had higher SNR and CNR than the single-shot TrueFISP PSIR (p<0.001). Mean quality ratings for short-axis imaging were 4 (interquartile range, 3-4) for single-shot TrueFISP PSIR and 4 (interquartile range, 4-5) for MOCO PSIR (p<0.001). The scan time was faster for single-shot TrueFISP PSIR than for MOCO PSIR. The myocardial LGE results were similar with high agreement between the single-shot TrueFISP PSIR and MOCO PSIR (ICC=0.955-0.986). The MOCO PSIR sequence is feasible in children. MOCO PSIR is robust at high heart rates and can be performed without breath-holding with higher image-quality ratings than the single-shot TrueFISP PSIR.

Interatrial septal aneurysm mimicking an atrial myxoma on multiparametric cardiovascular magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Interatrial septal aneurysm (IASA) appears as a localised saccular deformity usually detected during routine echocardiography or stroke evaluation. Imaging hallmarks are &amp;gt;15mm prolapsing motion across the interatrial septum (IAS) and identical content to blood-pool, which are in contrast to this patient. Clinical case An 81-year-old asymptomatic man underwent transesophageal echocardiographic (TEE) right atrial mass assessment revealing a well-circumscribed, mobile mass attached to the interatrial septum suggestive of myxoma. Given previously-excised renal cell carcinoma, gadolinium contrast-enhanced cardiovascular magnetic resonance (CMR) imaging was performed for mass characterisation. Mass signal intensity (SI) was distinct to blood-pool, in keeping with mass content not being blood. Cine imaging revealed an isointense, mobile mass (Figure 1, Video 1) attached to the fossa ovalis. The mass was of intermediate SI isointense to myocardium on T1-weighted, and bright and hyperintense on T2-weighted imaging. First-pass perfusion (Video 2) and early enhancement imaging demonstrated a hypointense, non-perfusing mass. The mass hyperenhanced on late enhancement imaging excluding the differential of thrombus. Imaging findings were entirely consistent with atrial myxoma. Intraoperatively, the excised mass was actually confirmed as an IASA with exquisitely tight neck. Discussion This is the first case of IASA mimicking atrial myxoma on CMR imaging. We postulate that it behaved like a non-perfusing mass as its uniquely narrow neck resulted in extremely slow flow in and out. This permitted minimal blood with contrast entry which remained ‘trapped’ within, resulting in distinct SI to blood pool, and late hyperenhancement. Left atrial pressures forced the mass into the right atrium, preventing typical lateral IASA motion. Conclusion The diagnosis of IASA is best established with TEE while CMR imaging is the reference standard imaging modality for tissue characterization. It is vital to be able to identify and differentiate such entities to avoid misdiagnosis of an IASA as a cardiac myxoma or a malignant cardiac tumour. Nevertheless, we recognize the presence of limitation of imaging in this extraordinary case. Abstract Figure 1

Risk Stratification Guided by the Index of Microcirculatory Resistance and Left Ventricular End-Diastolic Pressure in Acute Myocardial Infarction.

The index of microcirculatory resistance (IMR) of the infarct-related artery and left ventricular end-diastolic pressure (LVEDP) are acute, prognostic biomarkers in patients undergoing primary percutaneous coronary intervention. The clinical significance of IMR and LVEDP in combination is unknown. IMR and LVEDP were prospectively measured in a prespecified substudy of the T-TIME clinical trial (Trial of Low Dose Adjunctive Alteplase During Primary PCI). IMR was measured using a pressure- and temperature-sensing guidewire following percutaneous coronary intervention. Prognostically established thresholds for IMR (>32) and LVEDP (>18 mm Hg) were predefined. Contrast-enhanced cardiovascular magnetic resonance imaging (1.5 Tesla) was acquired 2 to 7 days and 3 months postmyocardial infarction. The primary end point was major adverse cardiac events, defined as cardiac death/nonfatal myocardial infarction/heart failure hospitalization at 1 year. IMR and LVEDP were both measured in 131 patients (mean age 59±10.7 years, 103 [78.6%] male, 48 [36.6%] with anterior myocardial infarction). The median IMR was 29 (interquartile range, 17-55), the median LVEDP was 17 mm Hg (interquartile range, 12-21), and the correlation between them was not statistically significant (r=0.15; P=0.087). Fifty-three patients (40%) had low IMR (≤32) and low LVEDP (≤18), 18 (14%) had low IMR and high LVEDP, 31 (24%) had high IMR and low LVEDP, while 29 (22%) had high IMR and high LVEDP. Infarct size (% LV mass), LV ejection fraction, final myocardial perfusion grade ≤1, TIMI (Thrombolysis In Myocardial Infarction) flow grade ≤2, and coronary flow reserve were associated with LVEDP/IMR group, as was hospitalization for heart failure (n=18 events; P=0.045) and major adverse cardiac events (n=21 events; P=0.051). LVEDP>18 and IMR>32 combined was associated with major adverse cardiac events, independent of age, estimated glomerular filtration rate, and infarct-related artery (odds ratio, 5.80 [95% CI, 1.60-21.22] P=0.008). The net reclassification improvement for detecting major adverse cardiac events was 50.6% (95% CI, 2.7-98.2; P=0.033) when LVEDP>18 was added to IMR>32. IMR and LVEDP in combination have incremental value for risk stratification following primary percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02257294.

Pixel-wise quantification of myocardial perfusion using spatial Tikhonov regularization

Quantification of myocardial perfusion by contrast-enhanced cardiovascular magnetic resonance imaging (CMR) aims for an observer independent and reproducible risk assessment of cardiovascular disease. Currently, the data used for the pixel-wise analysis of cardiac perfusion are either filtered prior to a fitting procedure, which inherently reduces the spatial resolution of data; or all pixels are considered without any regularization or prior filtering, which yields an unstable fit in the presence of low signal-to-noise ratio. Here, we propose a new pixel-wise analysis based on spatial Tikhonov regularization which exploits the spatial smoothness of the data and ensures accurate quantification even for images with low signal-to-noise ratio. The regularization parameter is determined automatically by an L-curve criterion. We study the performance of our method on a numerical phantom and demonstrate that the method reduces significantly the root-mean square error in the perfusion estimate compared to a non-regularized fit. In patient data our method allows us to recover the myocardial perfusion and to distinguish between healthy and ischemic regions.

Myocardial blood flow estimates from dynamic contrast-enhanced magnetic resonance imaging: three quantitative methods

Dynamic contrast-enhanced cardiovascular magnetic resonance imaging can be used to quantitatively assess the myocardial blood flow (MBF), recovering the tissue impulse response function for the transit of a gadolinium bolus through the myocardium. Several deconvolution techniques are available, using various models for the impulse response. The method of choice may influence the results, producing differences that have not been deeply investigated yet. Three methods for quantifying myocardial perfusion have been compared: Fermi function modelling (FFM), the Tofts model (TM) and the gamma function model (GF), with the latter traditionally used in brain perfusion MRI. Thirty human subjects were studied at rest as well as under cold pressor test stress (submerging hands in ice-cold water), and a single bolus of gadolinium weighing 0.1 ± 0.05 mmol kg−1 was injected. Perfusion estimate differences between the methods were analysed by paired comparisons with Student’s t-test, linear regression analysis, and Bland–Altman plots, as well as also using the two-way ANOVA, considering the MBF values of all patients grouped according to two categories: calculation method and rest/stress conditions.Perfusion estimates obtained by various methods in both rest and stress conditions were not significantly different, and were in good agreement with the literature. The results obtained during the first-pass transit time (20 s) yielded p-values in the range 0.20–0.28 for Student’s t-test, linear regression analysis slopes between 0.98–1.03, and R values between 0.92–1.01. From the Bland–Altman plots, the paired comparisons yielded a bias (and a 95% CI)—expressed as ml/min/g—for FFM versus TM, −0.01 (−0.20, 0.17) or 0.02 (−0.49, 0.52) at rest or under stress respectively, for FFM versus GF, −0.05 (−0.29, 0.20) or −0.07 (−0.55, 0.41) at rest or under stress, and for TM versus GF, −0.03 (−0.30, 0.24) or −0.09 (−0.43, 0.26) at rest or under stress. With the two-way ANOVA, the results were p = 0.20 for the method effect (not significant), p < 0.0001 for the rest/stress condition effect (highly significant, as expected), whereas no interaction resulted between the rest/stress condition and method (p = 0.70, not significant). Considering a wider time-frame (60 s), the estimates for both rest and stress conditions were 25%–30% higher (p in the range 0.016–0.025) than those obtained in the 20 s time-frame.MBF estimates obtained by various methods under rest/stress conditions were not significantly different in the first-pass transit time, encouraging quantitative perfusion estimates in DCE-CMRI with the used methods.

Increased Prognostic Value of Query Amyloid Late Enhancement Score in Light-Chain Cardiac Amyloidosis.

Late gadolinium enhancement (LGE) pattern is a powerful imaging biomarker for prognosis of cardiac amyloidosis. It is unknown if the query amyloid late enhancement (QALE) score in light-chain (AL) amyloidosis could provide increased prognostic value compared with LGE pattern.Methods and Results:Seventy-eight consecutive patients with AL amyloidosis underwent contrast-enhanced cardiovascular magnetic resonance imaging. Patients with cardiac involvement were grouped by LGE pattern and analyzed using QALE score. Receiver operating characteristic curve was used to identify the optimal cut-off for QALE score in predicting all-cause mortality. Survival of these patients was analyzed with the Kaplan-Meier method and multivariate Cox regression. During a median follow-up of 34 months, 53 of 78 patients died. The optimal cut-off for QALE score to predict mortality at 12-month follow-up was 9.0. On multivariate Cox analysis, QALE score ≥9 (HR, 5.997; 95% CI: 2.665-13.497; P<0.001) and log N-terminal pro-brain natriuretic peptide (HR, 1.525; 95% CI: 1.112-2.092; P=0.009) were the only 2 independent predictors of all-cause mortality. On Kaplan-Meier analysis, patients with subendocardial LGE can be further risk stratified using QALE score ≥9. The QALE scoring system provides powerful independent prognostic value in AL cardiac amyloidosis. QALE score ≥9 has added value to differentiate prognosis in AL amyloidosis patients with a subendocardial LGE pattern.

Left Ventricular Non-Compaction: Mid-myocardial Distribution of Late Gadolinium Enhancement in Compacted Segments

Background: Cardiovascular Magnetic Resonance (CMR) with Late Gadolinium Enhancement (LGE) is a proven method for detecting myocardial fibrosis. Previous CMR studies described the distribution of LGE in patients with LVNC; however, it still remains unclear. The purpose of the study was to describe the distribution of LGE in patients meeting cardiovascular magnetic resonance criteria for Left Ventricular Non-Compaction (LVNC). Methods: We retrospectively enrolled 15 patients adult patients (11 males and 4 females; mean age, 42 ± 13 years) considered to meet standard CMR criteria for LVNC. For each patient, cine and contrast-enhanced CMR images were analyzed to evaluate LV systolic function and the prevalence and ex-tent of LGE. The presence or absence of LGE was qualitatively determined for each left ventricular myocardial segment. Results: The mean NC/C ratio was 4.6 ± 0.9. The areas of non-compaction were most commonly observed at the apex, the anterior and the lateral walls, mainly on their apical and mid-cavity segments. LGE was present in 11 of the 15 patients (73%). LGE was observed most frequently in the ventricular septum commonly on basal and mid-cavity segments. The distribution of LGE was midmyocardial (n=42; 67%), subepicardial (n=11; 18%), transmural (n=6; 10%) and subendocardial (n=3; 5%), in total of 62 LGE (+) left ventricular segments. No association was found between LGE and non-compaction at left ventricular segmental level (phi coefficient 0,021; p= 0.191). Conclusion: LGE was most often observed in the ventricular septum with mid-myocardial distribution. Distribution of LGE in patients with LVNC is observed in both non-compacted and compacted segments with prevalence of compacted zones. This maintenance the concept that LVNC is a diffuse process including both non-compacted and morphologically normal segments.

Remote magnetic targeting of iron oxide nanoparticles for cardiovascular diagnosis and therapeutic drug delivery: where are we now?

Magnetic resonance imaging (MRI) allows for an accurate assessment of both functional and structural cardiac parameters, and thereby appropriate diagnosis and validation of cardiovascular diseases. The diagnostic yield of cardiovascular MRI examinations is often increased by the use of contrast agents that are almost exclusively based on gadolinium compounds. Another clinically approved contrast medium is composed of superparamagnetic iron oxide nanoparticles (IONs). These particles may expand the field of contrast-enhanced cardiovascular MRI as recently shown in clinical studies focusing on acute myocardial infarction (AMI) and atherosclerosis. Furthermore, IONs open up new research opportunities such as remote magnetic drug targeting (MDT). The approach of MDT relies on the coupling of bioactive molecules and magnetic nanoparticles to form an injectable complex. This complex, in turn, can be attracted to and retained at a desired target inside the body with the help of applied magnetic fields. In comparison to common systemic drug applications, MDT techniques promise both higher concentrations at the target site and lower concentrations elsewhere in the body. Moreover, concurrent or subsequent MRI can be used for noninvasive monitoring of drug distribution and successful delivery to the desired organ in vivo. This review does not only illustrate the basic conceptual and biophysical principles of IONs, but also focuses on new research activities and achievements in the cardiovascular field, mainly in the management of AMI. Based on the presentation of successful MDT applications in preclinical models of AMI, novel approaches and the translational potential of MDT are discussed.

Myocardial adaptation to high-intensity (interval) training in previously untrained men with a longitudinal cardiovascular magnetic resonance imaging study (Running Study and Heart Trial).

To prospectively evaluate whether short-term high-intensity (interval) training (HI(I)T) induces detectable morphological cardiac changes in previously untrained men in cardiovascular magnetic resonance imaging. Eighty-four untrained volunteers were randomly assigned to a HI(I)T group (n=42; 44.1±4.7 years) or an inactive control group (n=42; 42.3±5.6 years). HI(I)T focused on interval runs (intensity: 95%-105% of individually calculated heart rate at the anaerobic threshold). Before and after 16 weeks, all subjects underwent physiological examination, stepwise treadmill test with blood lactate analysis, and contrast-enhanced cardiovascular magnetic resonance imaging (cine, tagging, and delayed enhancement). Indexed left ventricular (LV) and right ventricular (RV) volume (LV, 77.1±8.5-83.9±8.6; RV, 80.5±8.5-86.6±8.1) and mass (LV, 58.2±6.4-63.4±8.1; RV, 14.8±1.7-16.1±2.1) significantly increased with HI(I)T. Changes in LV and RV morphological parameters with HI(I)T were highly correlated with an increase in maximal aerobic capacity (VO2max) and a decrease in blood lactate concentration at the anaerobic threshold. Mean LV and RV remodeling index of HI(I)T group did not alter with training (0.76 ±0.09 and 0.24±0.10 g/mL, respectively [P=0.97 and P=0.72]), indicating balanced cardiac adaptation. Myocardial circumferential strain decreased after HI(I)T within all 6 basal segments (anteroseptal, P=0.01 and anterolateral, P<0.001). There was no late gadolinium enhancement in any of the participants before or post HI(I)T. Sixteen weeks of HI(I)T lead to measurable changes in cardiac atrial and ventricular morphology and function in previously untrained men. This correlates with improvements in parameters of endurance capacity. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01406730.

Contrast enhanced-cardiovascular MRI in patients with cor pulmonale

Objective To determine the characteristics of contrast enhanced-cardiovascular magnetic resonance imaging (CE-CMRI) in patients with cor pulmonale.Methods Twenty-one patients with cor pulmonale were prospectively included and underwent CMRI.Short-axis cine images of the heart were obtained for ventricular function assessment using a steady-state free precession sequence.For first-pass perfusion,a Turbo FLASH was performed after intravenous administration of 0.2 mmol/kg Gadopentetate dimeglumine.For delayed contrast enhancement (DCE),a short-axis phase-sensitive inversion recovery sequence was performed.Right ventricular function and myocardial contrasted volume in DCE were measured with Argus software.Spearman correlation analysis was conducted to examine the association between myocardial contrasted volume and right ventricular function.Results CMRI showed the enlarged right atrium and ventricle,bowing ventricular septum in 21 patients.Septal angle was (70± 11)°,Right ventricular end diastolic volume (RVEDV)and end systolic volume RVESV respectively were (205 ± 48) and (141±33) ml,stroke volume(RVSV) was (64±21) ml and ejection fraction RVEF was (32± 11)％.Average RV myocardial mass was (100±37) g.No abnormal lesions were observed in the first-pass perfusion imaging.All patients showed triangular DCE in the insertion points (IP) of the right ventricular free wall to the interventricular septum and one in middle layer of interventricular septum.The DCE myocardial volume was (13±3) ml.Spearman correlation showed DCE myocardial volume correlated with septal angle (r=0.419,P=0.033),RVESV (r=0.598,P=0.001),RVEF (r=-0.709,P=0.001)and average RV myocardial mass (r=0.441,P=0.024).Conclusions Negative first-pass perfusion and positive DCE are mainly present in patients with cor pulmonale.DCE is mainly present within the insertion points of the right ventricular free wall to the interventricular septum.DCE extent correlates with RV function. Key words: Pulmonary heart disease; Heart; Magnetic resonance imaging

Subclinical diastolic dysfunction in young adults with Type 2 diabetes mellitus: a multiparametric contrast-enhanced cardiovascular magnetic resonance pilot study assessing potential mechanisms.

To assess the cardiac, vascular, anthropometric, and biochemical determinants of subclinical diastolic dysfunction in younger adults with Type 2 diabetes mellitus (T2DM) using multiparametric contrast-enhanced cardiovascular magnetic resonance (CMR) imaging. Twenty adults <40 years with T2DM [mean age 31.8(6.6) years, T2DM duration 4.7(4.0) years] and 20 age and sex-matched controls [10 obese non-diabetic controls and 10 lean controls (LC)] were studied. Cardiac volumes and function, circumferential strain and peak early diastolic strain rate (PEDSR), myocardial perfusion reserve, aortic stiffness (distensibility, pulse-wave velocity), focal fibrosis on late gadolinium enhancement, and pre- and post-contrast T1 mapping for contrast agent partition coefficient (subset, n = 26) were determined by CMR. In the T2DM cohort, mean aortic distensibility correlated with PEDSR (r = 0.564, P = 0.023) and diabetes duration correlated inversely with PEDSR (r = -0.534, P = 0.015) on univariate analysis. There was a close association between PEDSR and peak systolic strain (r = -0.580, P = 0.007). In young adults with T2DM, diabetes duration and aortic distensibility were associated with diastolic dysfunction. Interventional studies are required to assess whether cardiac dysfunction can be reversed in this phenotype of patients.

Myocardial perfusion defects in scleroderma detected by contrast-enhanced cardiovascular magnetic resonance.

The authors investigated whether contrast-enhanced cardiovascular magnetic resonance (CMR) imaging may be used to detect early cardiac involvement in patients with systemic sclerosis (SSc). Twenty-six SSc patients (nine with diffuse cutaneous SSc and 17 with limited cutaneous SSc) and 13 sex- and age-matched healthy controls (HC) were studied. Contrast-enhanced CMR allowed the analysis of first-pass images (areas of hypo-enhancement indicating perfusion defects) and delayed images (persistent hyper-enhancement indicating fibrosis). Clinical variables including disease duration and presence of major visceral complications of SSc were investigated in each patient. Perfusion defects were detected in 53.8% of SSc patients but in none of the HC. Perfusion abnormalities were detected in 28.6% of SSc patients with disease duration less than 2years and in 29.2% of asymptomatic SSc patients. Delayed contrast enhancement was present in 25% of SSc patients but not in HC. All patients with delayed contrast enhancement showed first-pass hypoperfusion. Right ventricular wall thickness was significantly increased in all SSc patients when compared to HC (p<0.001); a similar trend was observed when SSc patients without pulmonary arterial hypertension were analysed (p<0.04). A trend to lower end-diastolic and end-systolic right ventricular volumes in SSc versus HC was observed (p<0.05 and p<0.04, respectively). Myocardial hypoperfusion is common in SSc and occurs early in the course of the disease. Co-localisation of perfusion defects and delayed contrast enhancement indicative of fibrosis suggests that myocardial hypoxia may play a role in the pathogenesis of myocardial fibrosis.

Fragmented QRS complexes are not hallmarks of myocardial injury as detected by cardiac magnetic resonance imaging in patients with acute myocardial infarction

Q waves on a 12-lead electrocardiography (ECG) are considered to be classic hallmarks of prior myocardial infarction. However, one study suggested that the fragmented QRS complex (fQRS) on ECG is a highly sensitive and specific marker of myocardial scarring on a nuclear stress test. The study aimed to investigate the diagnostic accuracy of fragmented QRS complexes compared with Q waves for myocardial injury detected by delayed contrast-enhanced cardiovascular magnetic resonance imaging (DE-CMRI) in subjects with acute myocardial infarction. Electrocardiograms of 190 subjects with myocardial infarction who underwent DE-CMR were analyzed. fQRS was defined by the presence of an additional R wave (R″), or notching of the S wave, or more than one R' in two contiguous leads. Delayed enhancement was observed in 180 (94.7%) patients. Transmural enhancement was noted in 78 (43.3%) and subendocardial enhancement in 102 (56.7%) patients. The sensitivity and specificity of Q waved and fQRS for diagnosing delayed enhancement were 59.4% vs. 66.7% and 90.0% vs. 40.0%. The area under the receiver-operator characteristics curve of delayed enhancement was 0.75 for Q waves and 0.53 for fQRS (p=0.04). The areas under the ROC curves of the transmurality of delayed enhancement were 0.44 for fQRS and 0.58 for Q waves (p=0.73). fQRS has poor accuracy for the detection of myocardial injury compared with Q waves. fQRS and Q waves are not valuable tools for the diagnosis transmural irreversible myocardial injury in acute myocardial infarction.

Myocardial late gadolinium enhancement in systemic lupus erythematosus as a marker of chronic inflammation

Background Cardiac involvement of patients with systemic lupus erythematosus (SLE) is one of the main complications contributing to morbidity and mortality, however a significant portion of patients presents with subclinical disease. Non-invasive contrast-enhanced cardiovascular magnetic resonance (CMR) imaging is a well-established diagnostic tool to identify myocardial tissue alterations and morphological and functional changes. In this study, we aimed to assess cardiac abnormalities in SLE patients using LGE-CMR and, furthermore, the relation of serological inflammatory biomarkers to the cardiac LGE-CMR findings.

Infarct tissue characterization in implantable cardioverter-defibrillator recipients for primary versus secondary prevention following myocardial infarction: a study with contrast-enhancement cardiovascular magnetic resonance imaging

Knowledge about potential differences in infarct tissue characteristics between patients with prior life-threatening ventricular arrhythmia versus patients receiving prophylactic implantable cardioverter-defibrillator (ICD) might help to improve the current risk stratification in myocardial infarction (MI) patients who are considered for ICD implantation. In a consecutive series of (ICD) recipients for primary and secondary prevention following MI, we used contrast-enhanced (CE) cardiovascular magnetic resonance (CMR) imaging to evaluate differences in infarct tissue characteristics. Cine-CMR measurements included left ventricular end-diastolic and end-systolic volumes (EDV, ESV), left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and mass. CE-CMR images were analyzed for core, peri, and total infarct size, infarct localization (according to coronary artery territory), and transmural extent. In this study, 95 ICD recipients were included. In the primary prevention group (n = 66), LVEF was lower (23 ± 9 % vs. 31 ± 14 %; P < 0.01), ESV and WMSI were higher (223 ± 75 ml vs. 184 ± 97 ml, P = 0.04, and 1.89 ± 0.52 vs. 1.47 ± 0.68; P < 0.01), and anterior infarct localization was more frequent (P = 0.02) than in the secondary prevention group (n = 29). There were no differences in infarct tissue characteristics between patients treated for primary versus secondary prevention (P > 0.6 for all). During 21 ± 9 months of follow-up, 3 (5 %) patients in the primary prevention group and 9 (31 %) in the secondary prevention group experienced appropriate ICD therapy for treatment of ventricular arrhythmia (P < 0.01). There was no difference in infarct tissue characteristics between recipients of ICD for primary versus secondary prevention, while the secondary prevention group showed a higher frequency of applied ICD therapy for ventricular arrhythmia.