Histological Validation of Cardiovascular Magnetic Resonance T1 Mapping for Assessing the Evolution of Myocardial Injury in Myocardial Infarction: An Experimental Study

OBJECTIVE

To determine whether T1 mapping could monitor the dynamic changes of injury in myocardial infarction (MI) and be histologically validated.

MATERIALS AND METHODS

In 22 pigs, MI was induced by ligating the left anterior descending artery and they underwent serial cardiovascular magnetic resonance examinations with modified Look-Locker inversion T1 mapping and extracellular volume (ECV) computation in acute (within 24 hours, n = 22), subacute (7 days, n = 13), and chronic (3 months, n = 7) phases of MI. Masson's trichrome staining was performed for histological ECV calculation. Myocardial native T1 and ECV were obtained by region of interest measurement in infarcted, peri-infarct, and remote myocardium.

RESULTS

Native T1 and ECV in peri-infarct myocardium differed from remote myocardium in acute (1181 ± 62 ms vs. 1113 ± 64 ms, p = 0.002; 24 ± 4% vs. 19 ± 4%, p = 0.031) and subacute phases (1264 ± 41 ms vs. 1171 ± 56 ms, p < 0.001; 27 ± 4% vs. 22 ± 2%, p = 0.009) but not in chronic phase (1157 ± 57 ms vs. 1120 ± 54 ms, p = 0.934; 23 ± 2% vs. 20 ± 1%, p = 0.109). From acute to chronic MI, infarcted native T1 peaked in subacute phase (1275 ± 63 ms vs. 1637 ± 123 ms vs. 1471 ± 98 ms, p < 0.001), while ECV progressively increased with time (35 ± 7% vs. 46 ± 6% vs. 52 ± 4%, p < 0.001). Native T1 correlated well with histological findings (R² = 0.65 to 0.89, all p < 0.001) so did ECV (R² = 0.73 to 0.94, all p < 0.001).

CONCLUSION

T1 mapping allows the quantitative assessment of injury in MI and the noninvasive monitoring of tissue injury evolution, which correlates well with histological findings.

Prognostic value of multiple cardiac magnetic resonance imaging parameters in patients with idiopathic dilated cardiomyopathy

PURPOSE

Our study aimed to comprehensively explore efficient prognostic indicators in idiopathic dilated cardiomyopathy (IDCM) patients with reduced left ventricular ejection fraction (LVEF<40%).

BACKGROUND

Prognostic value of cardiac magnetic resonance(CMR) parameters for IDCM have been inconsistent.

METHODS

126 IDCM patients with reduced LVEF (<40%) were retrospectively enrolled. Cardiac function parameters, myocardial strain indices and myocardial fibrosis were evaluated. Laboratory data also were analyzed. The endpoint was a combination of major adverse cardiac events (MACEs), including cardiac death, heart transplantation, and rehospitalization. Prognostic value was evaluated by the Kaplan-Meier method and Cox regression.

RESULTS

During a median follow-up of 31 months, 44 patients experienced MACEs, including 9 deaths, 1 heart transplantation, and 34 rehospitalizations due to heart failure. Univariate and multivariate Cox analyses showed that cardiac function and myocardial strain indexes were not associated with the prognosis of IDCM (all p>0.05). NT-proBNP (HR 1.5, 95%CI: 1.053 to 2.137), Late‑gadolinium enhancement(LGE) mass (HR 1.022, 95%CI: 1.005 to 1.038), and LGE mass/left ventricle mass were significant predictors (HR 1.027, 95%CI: 1.007 to 1.046) for MACEs, all p < 0.05. Besides, poorest prognosis was observed in IDCM patients with positive LGE combined with NT-proBNP (log-rank = 27.261, p ≤ 0.001).

CONCLUSION

NT-proBNP and extent of LGE were reliable predictors in IDCM patients with reduced LVEF. Additionally, presence of LGE combined with NT-proBNP showed the strongest prognostic value in IDCM with reduced LVEF. Myocardial strain parameters seemed to have no prognostic value in IDCM patients with reduced LVEF.

Late gadolinium enhancement is a risk factor for major adverse cardiac events in unrecognised myocardial infarction without apparent symptoms: a meta-analysis

AIM

To assess the prognostic role of unrecognised myocardial infarction (UMI) detected at late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMRII).

MATERIALS AND METHODS

Electronic databases including PubMed, EMBASE, Medline, and Cochrane were searched systematically for studies exploring the predictive value of UMI detected by LGE-CMRI for major adverse cardiac events (MACEs) and all-cause mortality in patients without apparent symptoms. Pooled hazard ratios (HRs) along with their 95% confidence intervals (CIs) were obtained from a random-effects model. Subgroup analyses were performed according to the different participants and outcomes.

RESULTS

Eight studies (2,009 participants) were identified comprising 442 patients with UMI detected at LGE-CMRI and 1,567 without UMI. The presence of UMI on LGE was associated with a significantly increased risk for MACEs (HRs: 3.44, 95% CI: 2.06 to 5.75; p<0.001) and all-cause mortality (HRs: 2.43, 95% CI: 1.00 to 5.87; p=0.05). In the subgroup analysis, the presence of UMI on LGE remained significantly associated with the risk of MACEs in patients with suspected coronary artery disease (HRs: 3.82, 95% CI: 2.49 to 5.85; p<0.01) and diabetes mellitus (HRs: 4.97, 95% CI: 3.02 to 8.18; p<0.01).

CONCLUSION

The presence of UMI detected by LGE-CMRI is associated with an increased risk of MACEs and all-cause mortality in patients without symptoms. LGE-CMRI could provide important prognostic information and guide risk stratification in patients with UMI.

Global longitudinal diastolic strain rate as a novel marker for predicting adverse outcomes in hypertrophic cardiomyopathy by cardiac magnetic resonance tissue tracking

AIM

To examine the prognostic value of global peak diastolic strain rate (PDSR) derived from cardiac magnetic resonance (CMR) tissue tracking (CMR-TT) in predicting adverse outcomes in hypertrophic cardiomyopathy (HCM) patients.

MATERIALS AND METHODS

A total of 98 patients diagnosed with HCM (44 patients had left ventricle [LV] outflow tract obstruction [LVOTO] and 54 patients did not) were enrolled and followed for the specified endpoint. LV global myocardial mechanics was assessed in all participants using CMR-TT at study entry.

RESULTS

Compared with the non-obstructive subgroup, the obstructive subgroup demonstrated deteriorated magnitude of LV global radial, circumferential, and longitudinal PDSR (all p<0.05). After a mean follow-up period of 4.5 years, 24 patients reached an endpoint before the end of the study. Furthermore, when using the specified cut-off value (0.33 1/s) of longitudinal PDSR, the Kaplan-Meier curve demonstrated that patients with lower longitudinal PDSR had a significantly lower freedom from major adverse cardiovascular events (MACE) compared with their counterparts in the non-obstructive, obstructive, and overall cohorts (all log-rank p<0.05). Multivariable analysis showed that longitudinal PDSR remained the strongest predictor of outcome after adjusting for baseline and CMR variables (hazard ratio, 2.65; 95% confidence interval, 2.21-11.44; p<0.05).

CONCLUSION

CMR-TT-derived longitudinal PDSR is probably considered a novel and easy-to-perform marker for predicting adverse outcomes in HCM patients, which is beneficial to risk stratification. Further confirmatory studies are needed.

Effect of prediabetes on the long-term all-cause mortality of patients undergoing percutaneous coronary intervention: A protocol for systematic review and meta analysis

BACKGROUND

Prediabetes is an abnormal metabolic state that develops prior to the onset of diabetes with proven to common comorbid states of coronary artery disease. However, whether prediabetes worsens prognosis after percutaneous coronary intervention remains controversial. The aim of this study is to summarize previous cohort studies and to specify the impact of prediabetes on the long-term outcomes after percutaneous coronary intervention.

METHODS

This meta-analysis will be performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines for conducting and reporting meta-analysis data. Pubmed, Embase and Google scholar will be systematically searched, and supplemented with manual searches of the included reference lists to identify cohort studies. Pooled effects on the discontinuous variables will be expressed by adjusted hazard ratios with 95% confidence intervals. All analyses will be performed with Stata 15.0 (StataCorp LP, College Station, TX).

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

This systematic review will provide new information and help enhance clinical decision-making on management of these patients.

REGISTRATION NUMBER

INPLASY202060079.

Assessment of left ventricular deformation in patients with type 2 diabetes mellitus by cardiac magnetic resonance tissue tracking

To quantify the global and regional left ventricular (LV) myocardial strain in type 2 diabetes mellitus (T2DM) patients using cardiac magnetic resonance (CMR) tissue-tracking techniques and to determine the ability of myocardial strain parameters to assessment the LV deformation. Our study included 98 adult T2DM patients (preserved LV ejection fraction [LVEF], 72; reduced LVEF, 26) and 35 healthy controls. Conventional LV function, volume-time curve parameters and LV remodeling index were measured using CMR. Global and regional LV myocardial strain parameters were measured using CMR tissue tracking and compared between the different sub-groups. Receiver operating characteristic analysis was used to assess the diagnostic accuracy. Regression analyses were conducted to determine the relationship between strain parameters and the LV remodeling index. The results show that global radial peak strain (PS) and circumferential PS were not significantly different between the preserved-LVEF group and control group (P > 0.05). However, longitudinal PS was significantly lower in the preserved-LVEF group than in the control group (P = 0.005). Multivariate linear and logistic regression analyses showed that global longitudinal PS was independently associated (β = 0.385, P < 0.001) with the LV remodeling index. In conclusion, early quantitative evaluation of cardiac deformation can be successfully performed using CMR tissue tracking in T2DM patients. In addition, global longitudinal PS can complement LVEF in the assessment of cardiac function.

Radiation doses in CT examinations from the West China Hospital, Sichuan University and setting local diagnostic references levels

Background

Our study aims to summarize the data of radiation doses collected from consecutive CT examinations by using the Radiometrics software and contributing to the establishment of the region’s diagnostic reference levels (DRLs).

Methods

The radiation doses in 158,463 CT examinations performed on 106,275 adults between April 2017 and April 2019 were retrospectively analyzed. The median value and interquartile range (IQR) of volumetric CT dose index (CTDIvol), dose-length product (DLP), effective dose (ED), and size-specific dose estimate (SSDE) were calculated according to the scanning region.

Results

The median CTDIvol (mGy) for each scanning region was 42.3 (head), 6.2 (chest), and 9.0 (abdomen). The median DLPs (mGy.cm) for single-phase, multi-phase, and all examinations were as follows: 607, 794, and 641 for the head; 220, 393, and 237 for the chest; 298, 1,141, and 570 for the abdomen. The median EDs (mSv) for single-phase, multi-phase, and all examinations are as follows: 1.6, 2.6, and 1.8 for the head; 5.1, 8.1, and 5.3 for the chest; 5.8, 20.3, and 10.4 for the abdomen.

Conclusions

Our study’s results could provide a basis for the evaluation of CT scanning radiation dosage and supply evidence for the establishment of local DRLs in China’s Sichuan Province.

The combined effects of cardiac geometry, microcirculation, and tissue characteristics on cardiac systolic and diastolic function in subclinical diabetes mellitus-related cardiomyopathy

BACKGROUND

Diabetes mellitus-related cardiomyopathy has recently been described as a distinct progression of left ventricular (LV) systolic and diastolic dysfunction. Pathological changes in the myocardium may explain the development of two different phenotypes. We evaluated the effects of LV geometry, myocardial microcirculation, and tissue characteristics on cardiac deformation in patients with subclinical type 2 diabetes mellitus (T2DM) utilizing multiparametric cardiac magnetic resonance (CMR) imaging.

METHODS

A total of 135 T2DM patients and 55 matched controls were prospectively enrolled and performed multiparametric CMR examination. CMR-derived parameters including cardiac geometry, function, microvascular perfusion, T1 mapping, T2 mapping, and strain were analyzed and compared between T2DM patients and controls.

RESULTS

The univariable and multivariable analysis of systolic and diastolic function revealed that longer duration of diabetes was associated with decreased longitudinal peak systolic strain rate (PSSR-L) (β = 0.195, p = .013), and higher remodeling index and higher extracellular volume (ECV) tended to correlate with decreased longitudinal peak diastolic strain rate (PDSR-L) (remodeling index, β = -0.339, p = .000; ECV, β = -0.172, p = .026), whereas microvascular perfusion index and T2 value affected both PSSR-L (perfusion index, β = -0.328, p = .000; T2 value, β = 0.306, p = .000) and PDSR-L (perfusion index, β = 0.209, p = .004; T2 value, β = -0.275, p = .000) simultaneously.

CONCLUSIONS

The LV concentric remodeling and myocardial fibrosis correlated with diastolic function, and perfusion function and myocardial edema were associated with both LV systolic and diastolic function.

Protective role of beta-blockers in chemotherapy-induced cardiotoxicity-a systematic review and meta-analysis of carvedilol

Some randomized controlled trials (RCTs) have tested the efficacy of beta-blockers as prophylactic agents on cancer therapy-induced cardiotoxicity; however, the quality of this evidence remains undetermined. This systematic review and meta-analysis study aims to evaluate the prophylactic effects of beta-blockers, especially carvedilol, on chemotherapy-induced cardiotoxicity. RCTs were identified by searching the MEDLINE (PubMed), Embase (OvidSP), Cochrane CENTRAL (OvidSP), etc., until December 2017. Inclusion criteria were randomized clinical trial and adult cancer patients started beta-blockers before chemotherapy. We evaluated the mean differences (MD) by fixed- or random-effects model and the odds ratio by Peto’s method. Primary outcome was the left ventricular ejection fraction (LVEF) of patients after chemotherapy, and secondary outcomes were all-cause mortality, clinically overt cardiotoxicity, and other echocardiographic measurements. In total, we included six RCTs that used carvedilol as a prophylactic agent in patients receiving chemotherapy. The LVEF was not significantly distinct between those using carvedilol and placebo after chemotherapy (MD, 1.74; 95% confidence interval (CI), − 0.18 to 3.66; P = 0.08). The incidence of clinically overt cardiotoxicity was lower in the carvedilol group compared with the control group (Peto OR, 0.42; 95% CI, 0.20–0.89; P = 0.02). Furthermore, after chemotherapy, the LV end-diastolic diameter did not increase in the carvedilol group compared with the placebo group (MD, − 1.41; 95% CI, − 2.32 to − 0.50; P = 0.002). The prophylactic use of carvedilol exerted no impact on the early asymptomatic LVEF decrease but seemed to attenuate the frequency of clinically overt cardiotoxicity and prevent ventricular remodeling.

The prognostic value of right ventricular deformation derived from cardiac magnetic resonance tissue tracking for all-cause mortality in light-chain amyloidosis patients

Background

Early detection of right ventricular (RV) dysfunction is vital for determining the prognosis of light-chain amyloidosis (AL) patients. While few studies focused on RV deformation due to the limitation of research methods. The aim of this study was to determine the prognostic significance of RV myocardial strain in AL patients assessed by cardiac magnetic resonance (CMR) tissue tracking.

Methods

Sixty-four AL patients (28 females and 36 males, mean age 58±12.8 years old; range 25-81 years old) were enrolled from 1 October 2014 through 31 March 2017 and compared with 20 age- and sex-matched controls. Fifty-one AL patients met the criteria for cardiac amyloidosis (CA). Deformation parameters of both RV and left ventricle (LV) were measured by the CMR tissue tracking technique including myocardial global radial peak strain (GRPS), global circumferential peak strain (GCPS), and global longitudinal peak strain (GLPS). The follow-up time was 20 months or until the occurrence of death.

Results

Thirty-two (50%) had preserved RV ejection fraction (RVEF ≥45%). AL patients had significantly lower RV-GRPS (20.3±2.12 vs. 31.31±7.61), GCPS (-2.12±0.88 vs. -13.71±2.53), and GLPS (-5.33±0.64 vs. -14.239±2.99) than controls even RVEF remain preserved (all P<0.001). Compared with controls and patients without CA, RV-GRPS (12.26±1.26 vs. 29.72±3.54, P<0.001) and RV-GLPS (-3.78±2.25 vs. -5.66±2.08, P<0.05) were significantly lower in patients with CA. Cox multivariate analyses demonstrated that RV-GRPS [hazard ratio (HR) =0.93, 95% CI: 0.88-0.98, P=0.007] and Mayo stage were (HR =3.11, 95% CI: 1.30-7.41, P=0.01) predictors of mortality in AL patients.

Conclusions

CMR tissue tracking is a feasible and highly reproducible technique for the analysis of RV deformation and could aid in the early diagnosis of RV involvement in AL patients. RV-GRPS of RV strain and Mayo stage provides prognostic information about mortality in AL patients.

Left ventricular global function index by magnetic resonance imaging - a novel marker for differentiating cardiac amyloidosis from hypertrophic cardiomyopathy

Differentiating cardiac amyloidosis (CA) from hypertrophic cardiomyopathy (HCM) remains a clinical challenge, particularly in those with preserved left ventricular ejection fraction (LVEF) and similar hypertrophy. This study aimed to use left ventricular global function index (LVGFI) and myocardial contraction fraction (MCF) to discriminate CA from HCM without using contrast agents on cardiovascular magnetic resonance imaging (CMR). In total, we included 68 CA patients, 90 HCM patients, and 35 healthy controls. We found that LVGFI had excellent diagnostic performance in differentiating CA from HCM (area under the curve (AUC) = 0.91, 95% CI [0.86-0.95]), even in the challenging conditions of similar hypertrophy (AUC = 0.92, 95% CI [0.87-0.97]) and preserved LVEF (AUC = 0.90, 95% CI [0.84-0.96]). LVGFI also had significant correlations with LGE extent, NT-proBNP and troponin T (all p < 0.001). Multiple logistic regression analysis revealed that LVGFI was an independent predictor of CA (odds ratio: 1.11, 95% CI: 1.01-1.23; p = 0.034). In conclusion, LVGFI is a novel and clinically useful parameters with excellent ability in determining myocardial function and differentiating cardiac amyloidosis from hypertrophic cardiomyopathy.

Assessing right ventricular deformation in hypertrophic cardiomyopathy patients with preserved right ventricular ejection fraction: a 3.0-T cardiovascular magnetic resonance study

To assess the global and regional right ventricular (RV) deformation in hypertrophic cardiomyopathy (HCM) patients with preserved right ventricular ejection fraction (RVEF) using 3.0-T cardiovascular magnetic resonance tissue tracking (CMR-TT). Eighty-two HCM patients and 32 age- and sex-matched healthy controls were enrolled. HCM patients were divided into groups depending on the presence or absence of right ventricular hypertrophy (RVH), RV late gadolinium enhancement (RV-LGE), and left ventricular outflow tract obstruction (LVOTO), respectively. The RV global and apical longitudinal peak strain (LPS) in HCM patients with RVH were significantly lower than that in HCM patients without RVH and controls (P < 0.05). The global, apical and mid-ventricular LPS in HCM patients with RV-LGE were significantly lower than that in HCM patients without RV-LGE and controls (P < 0.05). Lower LPS was demonstrated in HCM patients without RV-LGE compared with controls in apical and mid-ventricular levels (P < 0.05). No significant difference was found regarding global and regional LPS in HCM patients with LVOTO compared without LVOTO (all P > 0.05). CMR-TT was able to detect subclinical RV myocardial deformation prior to RVEF impairment, which was more severe in the presence of RVH and RV-LGE.

Prognostic value of dual-source computed tomography (DSCT) angiography characteristics in anomalous coronary artery from the opposite sinus (ACAOS) patients: a large-scale retrospective study

Background

Most reported cases of right anomalous coronary artery from the opposite sinus (R-ACAOS) have benign clinical outcomes. However, patients with left ACAOS (L-ACAOS) and some of the patients with R-ACAOS are more at risk for arrhythmias and sudden cardiac death, which remains a major concern. Here we report the prevalence and anatomical features of ACAOS patients. Moreover, we explore the high-risk morphological signs and evaluate their mid-term prognostic value in R-ACAOS patients without surgical intervention.

Methods

Data from coronary computed tomography angiography (CTA) of 30,593 patients, pertaining to a single center over 5 consecutive years, were retrospectively analyzed. The image analysis included stenosis severity ranking and high-risk anatomy evaluation, based on the commercially available image post-processing software OsirX. Patients with R-ACAOS and without evidence of coronary atherosclerosis (CAD) were followed-up, with recording of the cardiovascular clinical events. Cox regression analysis was performed to identify the potential anatomical risk factors of cardiovascular clinical events for non-CAD R-ACAOS patients, using R project.

Results

The prevalence of ACAOS in the study population was 0.69% (211/30593). Significant differences were found between patients with mild (< 50%) and severe (> 50%) stenosis, in terms of height-to-weight ratio (HW ratio), take-off angle, and proximal stenosis length. A total of 54 cardiovascular clinical events were observed among 108 non-CAD R-ACAOS patients and an average follow-up of 27.8 ± 18.7 months. Among those patients’ anatomical features, stenosis severity was the main risk factor for cardiovascular clinical events during the mid-term follow-up, with a risk ratio of 4.14 (95% CI: 1.78 to 9.63, P < 0.001).

Conclusions

Among patients referred to coronary CTA, the overall incidence of ACAOS was 0.69%. For patients with R-ACAOS, severe stenosis was the independent risk factor of adverse clinical events in the mid-term follow-up, and positive clinical intervention might be needed to help them avoid the malignant clinical events.

Prognostic value of heart failure in hemodialysis-dependent end-stage renal disease patients with myocardial fibrosis quantification by extracellular volume on cardiac magnetic resonance imaging

Background

End-stage renal disease (ESRD) patients are at high cardiovascular risk, and myocardial fibrosis (MF) accounts for most of their cardiac events. The purpose of this study is to investigate the prognostic value and risk stratification of MF as measured by extracellular volume (ECV) on cardiac magnetic resonance (CMR) for heart failure (HF) in patients with hemodialysis-dependent ESRD.

Methods

Sixty-six hemodialysis ESRD patients and 25 matched healthy volunteers were prospectively enrolled and underwent CMR to quantify multiple parameters of MF by T1 mapping and late gadolinium enhancement (LGE). All ESRD patients were followed up for 11–30 months, and the end-point met the 2016 ESC guidelines for the definition of HF.

Results

Over a median follow-up of 18 months (range 11–30 months), there were 26 (39.39%) guideline-diagnosed HF patients in the entire cohort of ESRD subjects. The native T1 value was elongated, and ECV was enlarged in the HF cohort relative to the non-HF cohort and normal controls (native T1, 1360.10 ± 50.14 ms, 1319.39 ± 55.44 ms and 1276.35 ± 56.56 ms; ECV, 35.42 ± 4.42%, 31.85 ± 3.01% and 26.97 ± 1.87%; all p<0.05). In the cardiac strain analysis, ECV was significantly correlated with global radial strain (GRS) (r = − 0.501, p = 0.009), global circumferential strain (GCS) (r = 0.553, p = 0.005) and global longitudinal strain (GLS) (r = 0.507, p = 0.008) in ESRD patients with HF. Cox proportional hazard regression models revealed that ECV (hazard ratio [HR] = 1.160, 95% confidence interval: 1.022 to 1.318, p = 0.022) was the only independent predictor of HF in ESRD patients. It also had a higher diagnostic accuracy for detecting MF (area under the curve [AUC] = 0.936; 95% confidence interval: 0.864 to 0.976) than native T1 and post T1 (all p ≤ 0.002). Kaplan-Meier analysis revealed that the high-ECV group had a shorter median overall survival time than the low-ECV group (18 months vs. 20 months, log-rank p = 0.046) and that ESRD patients with high ECV were more likely to have HF.

Conclusions

Myocardial fibrosis quantification by ECV on CMR T1 mapping was shown to be an independent risk factor of heart failure, providing incremental prognostic value and risk stratification for cardiac events in ESRD patients.

Trial registration

Chinese Clinical Trial Registry ChiCTR-DND-17012976, 13/12/2017, Retrospectively registered.

Left Ventricular Deformation in Patients with Connective Tissue Disease: Evaluated by 3.0T Cardiac Magnetic Resonance Tissue Tracking

The aim of this study was to assess left ventricular (LV) myocardial strain in patients with connective tissue disease (CTD) and compare LV deformation between subgroups of idiopathic inflammatory myopathy (IIM) and non-IIM. Ninety-eight patients with CTD, comprising 56 with IIM and 42 with non-IIM, and 30 healthy subjects were enrolled and underwent 3.0T cardiac magnetic resonance imaging (MRI) scanning. The LV function and strain parameters were measured and assessed. Our result revealed that CTD patients had preserved LV ejection fraction (60.85%) and had significantly decreased global and regional peak strain (PS) in radial, circumferential, and longitudinal directions (all p < 0.05). IIM patients showed significantly reduced global longitudinal PS (GLPS) and longitudinal PS at apical slice, whereas all strain parameters decreased in non-IIM patients. Except GLPS and longitudinal PS at apical slice, all strain parameters in non-IIM patients were lower than those in IIM patients. By Pearson’s correlation analysis, the LV global radial and circumferential PS were correlated to N-terminal pro-brain natriuretic peptide level and LV ejection fraction in both IIM and non-IIM patients. This study indicated that CTD patients showed abnormal LV deformation despite with preserved LVEF. The impairment of LV deformation differed between IIM and non-IIM patients.

Serial coronary computed tomography angiography-verified coronary plaque progression: comparison of stented patients with or without diabetes

BACKGROUND

Patients with Diabetes mellitus (DM) are susceptible to coronary artery disease (CAD). However, the impact of DM on plaque progression in the non-stented segments of stent-implanted patients has been rarely reported. This study aimed to evaluate the impact of DM on the prevalence, characteristics and severity of coronary computed tomography angiography (CCTA) verified plaque progression in stented patients. A comparison between diabetic and non-diabetic patients was performed.

METHODS

A total of 98 patients who underwent clinically indicated serial CCTAs arranged within 1 month before and at least 6 months after percutaneous coronary intervention (PCI) were consecutively included. All the subjects were categorized into diabetic group (n = 36) and non-diabetic groups (n = 62). Coronary stenosis extent scores, segment involvement scores (SIS), segment stenosis scores (SSS) at baseline and follow-up CCTA were quantitatively assessed. The prevalence, characteristics and severity of plaque progression was evaluated blindly to the clinical data and compared between the groups.

RESULTS

During the median 1.5 year follow up, a larger number of patients (72.2% vs 40.3%, P = 0.002), more non-stented vessels (55.7% vs 23.2%, P < 0.001) and non-stented segments (10.3% vs 4.4%, P < 0.001) showed plaque progression in DM group, compared to non-DM controls. More progressive lesions in DM patients were found to be non-calcified plaques (31.1% vs 12.8%, P = 0.014) or non-stenotic segments (6.6% vs 3.0%, p = 0.005) and were more widely distributed on left main artery (24.2% vs 5.2%, p = 0.007), the right coronary artery (50% vs 21.1%, P = 0.028) and the proximal left anterior artery (33.3% vs 5.1%, P = 0.009) compared to non-DM patients. In addition, DM patients possessed higher numbers of progressive segments per patient, ΔSIS and ΔSSS compared with non-DM individuals (P < 0.001, P = 0.029 and P < 0.001 respectively). A larger number of patients with at least two progressive lesions were found in the DM group (P = 0.006). Multivariate logistic regression analysis demonstrated that DM (OR: 4.81; 95% CI 1.64-14.07, P = 0.004) was independently associated with plaque progression.

CONCLUSIONS

DM is closely associated with the prevalence and severity of CCTA verified CAD progression. These findings suggest that physicians should pay attention to non-stent segments and the management of non-stent segment plaque progression, particularly to DM patients.

Assessment of intracardiac and extracardiac anomalies associated with coarctation of aorta and interrupted aortic arch using dual-source computed tomography

To evaluate the value of dual-source computed tomography (DSCT) compared with transthoracic echocardiography (TTE) in assessing intracardiac and extracardiac anomalies in patients with coarctation of aorta (CoA) and interrupted aortic arch (IAA). Seventy-five patients (63 with CoA and 12 with IAA) who received preoperative DSCT and TTE were retrospectively studied. Intracardiac and extracardiac anomalies were recorded and compared by DSCT and TTE, in reference to surgical or cardiac catheterization findings. A total of 155 associated anomalies were finally found. Collateral circulation (56, 74.70%), patent ductus arteriosus (PDA; 41, 54.67%) were the most common anomalies. PDA, aortopulmonary window, and collateral circulation were more frequently present in patients with IAA than those with CoA (100% vs. 46.03%, 16.67% vs. 0%, and 100% vs. 69.84%, respectively, all p < 0.05). DSCT was superior to TTE in assessing associated extracardiac-vascular anomalies (sensitivity: 100% vs. 39.81%; specificity: 100% vs. 100%; positive predictive value: 100% vs. 100%; negative predictive value: 100% vs. 76.06%). Extracardiac-vascular anomalies, including collateral circulation and PDA, were the most common anomalies in patients with IAA and CoA. Compared with TTE, DSCT is more reliable in providing an overall preoperative evaluation of morphological features and extracardiac anomalies for surgical planning.

Accurate identification of myocardial viability after myocardial infarction with novel manganese chelate-based MR imaging

We developed a novel manganese (Mn²⁺ ) chelate for magnetic resonance imaging (MRI) assessment of myocardial viability in acute and chronic myocardial infarct (MI) models, and compared it with Gadolinium-based delay enhancement MRI (Gd³⁺ -DEMRI) and histology. MI was induced in 14 rabbits by permanent occlusion of the left circumflex coronary artery. Gd³⁺ -DEMRI and Mn²⁺ chelate-based delayed enhancement MRI (Mn²⁺ chelate-DEMRI) were performed at 7 days (acute MI, n = 8) or 8 weeks (chronic MI, n = 6) after surgery with sequential injection of 0.15 mmol/kg Gd³⁺ and Mn²⁺ chelate. The biodistribution of Mn²⁺ in tissues and blood was measured at 1.5 and 24 h. Blood pressure, heart rate (HR), left ventricular (LV) function, and infarct fraction (IF) were analyzed, and IF was compared with the histology. The Mn²⁺ chelate group maintained a stable hemodynamic status during experiment. For acute and chronic MI, all rabbits survived without significant differences in HR or LV function before and after injection of Mn²⁺ chelate or Gd³⁺ (p > 0.05). Mn²⁺ chelate mainly accumulated in the kidney, liver, spleen, and heart at 1.5 h, with low tissue uptake and urine residue at 24 h after injection. In the acute MI group, there was no significant difference in IF between Mn²⁺ chelate-DEMRI and histology (22.92 ± 2.21% vs. 21.79 ± 2.25%, respectively, p = 0.87), while Gd³⁺ -DEMRI overestimated IF, as compared with histology (24.54 ± 1.73%, p = 0.04). In the chronic MI group, there was no significant difference in IF between the Mn²⁺ chelate-DEMRI, Gd³⁺ -DEMRI, and histology (29.50 ± 11.39%, 29.95 ± 9.40%, and 29.00 ± 10.44%, respectively, p > 0.05), and all three were well correlated (r = 0.92-0.96, p < 0.01). We conclude that the use of Mn²⁺ chelate-DEMRI is reliable for MI visualization and identifies acute MI more accurately than Gd³⁺ -DEMRI.

Cardiac magnetic resonance feature tracking for quantifying right ventricular deformation in type 2 diabetes mellitus patients

To determine the feasibility of deformation analysis in the right ventricle (RV) using cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) in type 2 diabetes mellitus (T2DM) patients. We enrolled 104 T2DM patients, including 14 with impaired right ventricular ejection fraction (RVEF) and 90 with preserved RVEF, and 26 healthy controls in this prospective study. CMR was used to determine RV feature-tracking parameters. RV strain parameters were compared among the controls, patients with preserved and reduced RVEF. Binary logistic regression was used to predict RV dysfunction. Receiver operating characteristic analysis was used to assess the diagnostic accuracy. The agreement was tested by Bland-Altman analysis. Compared with controls, longitudinal and circumferential global peak strain (PS) and PS at mid-ventricular, apical slices were significantly decreased in T2DM patients with or without reduced RVEF (p < 0.05). Within the T2DM patients, the global longitudinal PS (GLPS) and the longitudinal PS at mid-ventricular segments were significantly reduced in the reduced RVEF group than in preserved RVEF groups (p < 0.05). GLPS was an independent predictor of RV dysfunction (odds ratio: 1.246, 95% CI: 1.037-1.496; p = 0.019). The GLPS demonstrated greater diagnostic accuracy (area under curve: 0.716) to predict RV dysfunction. On Bland-Altman analysis, global circumferential PS and GLPS had the best intra- and inter-observer agreement, respectively. In T2DM patients, CMR-FT could quantify RV deformation and identify subclinical RV dysfunction in those with normal RVEF. Further, RV strain parameters are potential predictors for RV dysfunction in T2DM patients.

CT compared to MRI for functional evaluation of the right ventricle: a systematic review and meta-analysis

OBJECTIVE

Right ventricular function (RVF) is a strong predictor of adverse cardiac events; however, the reference standard for RVF assessment, MRI, is limited in some patients for whom accurate evaluation of RVF is essential, like those with COPD or non-MR compatible metal implants. We conducted this meta-analysis to evaluate whether CT was as accurate as MRI for the assessment of RVF.

METHOD

We conducted a meta-analysis of studies retrieved from PubMed, Embase, and Cochrane Central searches to evaluate the differences and correlations between the following RVF parameters as measured by CT and MRI: end diastole volume (EDV), end systole volume (ESV), right ventricular ejection fraction (RVEF), and stroke volume (SV).

RESULTS

Sixteen studies that used disk summation (637 subjects) and three studies that used three-dimensional reconstruction were included. For the 16 studies, the pooled standard mean differences (95% confidence interval) were 1.04 (- 2.59, 4.67) for EDV, 1.22 (1.50, 3.95) for ESV, - 0.65 (- 2.60, 1.29) for RVEF, and - 0.37 (- 3.64, 2.90) for SV. The overall correlation coefficient (r) values were 0.98 for EDV, 0.95 for ESV, 0.98 for RVEF, and 0.97 for SV. The mean difference between the two methods was not statistically significant (overall effect Z test, p > 0.1).

CONCLUSION

CT can assess RVF with accuracy comparable to that of MRI. Thus, CT is a valid alternative to MRI.

KEY POINTS

• CT could help clinicians to assess RVF as accurately as MRI can, with satisfactory repeatability.

Evaluation of myocardial fibrosis in diabetes with cardiac magnetic resonance T1-mapping: Correlation with the high-level hemoglobin A1c

AIM

The aim of the study was to assess the extracellular volume fraction (ECV) in type 2 diabetes mellitus (T2DM) patients with different level of hemoglobin A1c (HbA1c) by cardiac magnetic resonance (CMR), and the ability of HbA1c to predict myocardial fibrosis.

METHODS

In total, 80 T2DM patients and 20 age- and sex-matched controls were prospective enrolled and underwent CMR to obtain ECV value and LV function parameters. We divided all patients into a group of HbA1c < 7.0% and a group of HbA1c ≥ 7.0%.

RESULTS

In the higher HbA1c group the ECV value (all p < 0.001) was higher than both lower HbA1c group (36.23% vs. 32.19%, p < 0.001) and controls (36.23% vs. 29.73%, p < 0.001). HbA1c was positively associated (β = 0.36, p = 0.004) with ECV, and it was also an independent predictor of myocardial fibrosis (OR = 2.00, P = 0.014). The ROC analysis showed that 7.1% was the optimal cutoff value of HbA1c that predicted the risk of myocardial fibrosis with high diagnostic accuracy (area under the curve = 0.78).

CONCLUSION

T1 mapping provided myocardial fibrosis information in T2DM patients. HbA1c is positively correlated with myocardial fibrosis and can be an independently predictor of myocardial fibrosis, which may be helpful for the clinical decision-making of blood glucose control.