Coronary computed tomography angiography in acute chest pain: A sustainable model with remote support.

PURPOSE: To propose a sustainable model of coronary computed tomography angiography (CCTA) use in acute coronary syndrome (ACS) in emergency department (ED) using a partially based teleradiology reporting model. We also analyzed impact of the protocol on short- and long-term patient's outcome. METHODS: During a 12-month period, 104 consecutive patients admitted to the ED for acute chest pain (ACP) with low-to-intermediate risk of ACS were selected and underwent CCTA. Medical reporting was based on a model combining on-site physician and a remote radiologist supported by a web client-based teleradiology system, covering a 24/7 service. CCTA findings were correlated with the incidence of major adverse cardiovascular events (MACEs) over a 5-year follow-up. RESULTS: CCTA ruled-out CAD in 76 patients (73.1%). Moderate (7.7%) to severe (19.2%) CAD was identified in 28 patients who were directly referred to functional tests or invasive angiography. The mean discharge time was 10.8 ± 5.8 h; patients with absent to mild disease were safely and quickly discharged. Remote reporting using a teleradiology platform was performed in 82/104 cases (78.9%), with slight impact on patient's discharge time (10.4 ± 5.6 vs. 12.1 ± 6.1 h, p: 0.24). MACEs at 6-month and at 5-year follow-up were 0.96% (n = 1/104) and 15.5% (n = 14/90). CONCLUSION: CCTA assessment of patients with ACP enables to quickly rule-out ACS, avoiding waste of time and resources, to identify patients with obstructive CAD which should be referred to subsequent tests and to stratify the risk of MACEs at short and long time. A partial teleradiology based 24/7 CCTA service is feasible and sustainable, even in small ED.

Early myocardial damage and microvascular dysfunction in asymptomatic patients with systemic sclerosis: A cardiovascular magnetic resonance study with cold pressor test.

PURPOSE: Cardiac involvement in Systemic Sclerosis (SSc) is increasingly recognized as a mayor cause of morbidity and mortality. The aim of present study is to investigate the early stages of cardiac involvement in SSc by Cardiovascular magnetic resonance (CMR), combining the non-invasive detection of myocardial inflammation and fibrosis using T2 and T1 mapping techniques and the assessment of microcirculatory impairment through perfusion response to cold pressor test (CPT). METHODS: 40 SSc patients (30 females, mean age: 42.1 years) without cardiac symptoms and 10 controls underwent CMR at 1.5 T unit. CMR protocol included: native and contrast-enhanced T1 mapping, T2 mapping, T2-weighted, cineMR and late gadolinium enhancement (LGE) imaging. Microvascular function was evaluated by comparing myocardial blood flow (MBF) on perfusion imaging acquired at rest and after CPT. Native myocardial T1 and T2 relaxation times, extracellular volume fraction (ECV), T2 signal intensity ratio, biventricular volumes and LGE were assessed in each patient. RESULTS: SSc patients had significantly higher mean myocardial T1 (1029±32ms vs. 985±18ms, p<0.01), ECV (30.1±4.3% vs. 26.7±2.4%, p<0.05) and T2 (50.1±2.8ms vs. 47±1.5ms, p<0.01) values compared with controls. No significant differences were found between absolute MBF values at rest and after CPT; whereas lower MBF variation after CPT was observed in SSc patients (+33 ± 14% vs. +44 ± 12%, p<0.01). MBF variation had inverse correlation with native T1 values (r: -0.32, p<0.05), but not with ECV. CONCLUSIONS: Myocardial involvement in SSc at preclinical stage increases native T1, T2 and ECV values, reflecting inflammation and fibrosis, and reduces vasodilatory response to CPT, as expression of microvascular dysfunction.

Role of autonomic dysfunction in the regulation of myocardial blood flow in systemic sclerosis evaluated by cardiac magnetic resonance.

AIM: Autonomic dysfunction (AD) is an early feature of systemic sclerosis (SSc). A regular endothelial function is a prerequisite for normal response of the myocardial blood flow (MBF) to cold pressure test (CPT). The aim of the study was to evaluate the relation between MBF and AD at rest and after CPT in asymptomatic SSc patients. METHODS: Twenty SSc patients and 10 age-, sex- and body mass index-matched healthy controls underwent cardiac magnetic resonance at rest and after CPT. All subjects underwent 24 hours ambulatory 3-channel electrocardiogram Holter to evaluate AD by heart rate variability. RESULTS: We did not observe any significant difference in MBF (mL/g/min) at rest and after CPT between SSc patients and healthy controls. Delta of MBF (difference between MBF after CPT and rest MBF) was lower (P = 0.039) in SSc patients than healthy controls (0.28 [0.04-0.40] vs 0.33 [0.24-0.54]). The low frequency/high frequency (LF/HF) was higher (P = 0.002) in SSc patients than healthy controls (3 [1.7-6] vs 1.8 [1.1-2.8]). The high frequencies (HF), modulated mainly by paraympathetic system, was lower (P = 0.003) in SSc patients than healthy controls (30 [16-42] vs 36.5 [24-44]). Sympathetic hyperactivity, due to reduction of parasympathetic activity (HF), is present in SSc patients. A negative correlation was observed between Delta of MBF and LF/HF (r = -0.572, P = 0.0031). CONCLUSION: AD, characterized by sympathovagal imbalance due to a reduced parasympathetic tone with high LF/HF ratio, could be responsible for the reduced myocardial vasodilatory response after CPT.

Early myocardial gadolinium enhancement in patients with myocarditis: Validation of "Lake Louise consensus" criteria using a single bolus of 0.1mmol/Kg of a high relaxivity gadolinium-based contrast agent.

OBJECTIVES: Global early gadolinium enhancement (EGE) is an accepted cardiac magnetic resonance (CMR) criterion for diagnosis of myocarditis. However, recommended enhancement thresholds are based specifically on standard-relaxivity Gd-chelates. We evaluated the performance of a high relaxivity MR contrast agent for detection of myocardial hyperemia in patients referred for endomyocardial biopsy (EMB). METHODS: We retrospectively enrolled 54 patients (mean age: 44.1 years [range=18-77years]; 72% men) with suspected myocarditis who underwent CMR and EMB within four weeks of clinical onset. CMR imaging protocol included T2-weighted short tau inversion-recovery sequence, EGE and late gadolinium enhanced (LGE) imaging. For EGE imaging, free-breathing ECG-gated turbo spin echo T1-weighted (TSE T1w) sequences were acquired before and within the first three minutes after gadobenate dimeglumine (0.1mmol/Kg) administration. The ratio (EGEr) between myocardial and musculoskeletal early enhancement was calculated. Myocardial edema, EGE and late gadolinium enhancement (LGE) were correlated with EMB results. Receiver operating characteristic (ROC) curve analysis of EGE values was applied on the overall population. RESULTS: EMB revealed myocarditis in 34/54 patients. Sensitivity, specificity and accuracy values of 0.61, 0.85 and 0.70, respectively, were obtained for a standard EGE threshold (EGEr>4.0). ROC analysis revealed an area under the curve of 0.701 for EGEr (IC95%:0.556-0.846, p=0.014) and 0.706 for absolute enhancement (IC95%:0.563-0.849, p=0.012). Sensitivity, specificity and accuracy values were 0.67, 0.80 and 0.72, respectively, for myocardial edema and 0.76, 0.75 and 0.76, respectively, for LGE. CONCLUSIONS: High relaxivity contrast agents provide comparable results to standard-relaxivity chelates for EGE assessment in diagnosing myocarditis.

A feasible and automatic free tool for T1 and ECV mapping.

PURPOSE: Cardiac magnetic resonance (CMR) is a useful non-invasive tool for characterizing tissues and detecting myocardial fibrosis and edema. Estimation of extracellular volume fraction (ECV) using T1 sequences is emerging as an accurate biomarker in cardiac diseases associated with diffuse fibrosis. In this study, automatic software for T1 and ECV map generation consisting of an executable file was developed and validated using phantom and human data. METHODS: T1 mapping was performed in phantoms and 30 subjects (22 patients and 8 healthy subjects) on a 1.5T MR scanner using the modified Look-Locker inversion-recovery (MOLLI) sequence prototype before and 15 min after contrast agent administration. T1 maps were generated using a Fast Nonlinear Least Squares algorithm. Myocardial ECV maps were generated using both pre- and post-contrast T1 image registration and automatic extraction of blood relaxation rates. RESULTS: Using our software, pre- and post-contrast T1 maps were obtained in phantoms and healthy subjects resulting in a robust and reliable quantification as compared to reference software. Coregistration of pre- and post-contrast images improved the quality of ECV maps. Mean ECV value in healthy subjects was 24.5%±2.5%. CONCLUSIONS: This study demonstrated that it is possible to obtain accurate T1 maps and informative ECV maps using our software. Pixel-wise ECV maps obtained with this automatic software made it possible to visualize and evaluate the extent and severity of ECV alterations.

Diverticulum, or not Diverticulum, That Is the Question! Discussing About a Case of Left Ventricular Outpouching Associated With Bicuspid Aortic Valve Assessed by Cardiac Magnetic Resonance.

Congenital left ventricular outpouchings (LVOs) are infrequent myocardial malformations, comprising various overlapping abnormalities, whose characterization is often intricate in clinical practice using traditional non-invasive techniques. We describe a rare case of LVO associated with bicuspid aortic valve incidentally found in an asymptomatic adult patient. The LVO was located at basal level of the chamber, crescent-shaped with its largest diameter in short-axis view and presented a thin hypo-contractile wall without hyperintense areas on late gadolinium enhanced (LGE) images. This description corresponds to an overlap between usual definition of aneurism, fibrous and muscular diverticulum. The LVO was evaluated according with a classification recently proposed by Malakan Rad. In this case ventricular geometry was not respected, wall thickness was reduced and wall motion compromised therefore corresponding to a small IIc-type, which is considered having the poorest prognosis. Furthermore, the association with bicuspid aortic valve is very unusual. The patient refused surgery and preferred follow-up.

Tracheal Bronchus: High Resolution Computed Tomography diagnosis in a symptomatic patient.

A 75-year-old female underwent a High Resolution Computed Tomography (HRCT) scan for recurrent bronchitis and cough. HRCT images showed an anomalous supernumerary bronchus to the right upper lobe directly arising from the right side of distal trachea, corresponding to Tracheal Bronchus (TrB). TrB can cause recurrent right upper lobe pneumonia and special care is requiring during endotracheal intubation.