Diagnostic Yield of Cardiac Magnetic Resonance in Athletes with and without Features of the Athlete's Heart and Suspected Structural Heart Disease.

Cardiac magnetic resonance (CMR) is a second-line imaging test in cardiology. Balanced enlargement of heart chambers called athlete's heart (AH) is a part of physiological adaptation to regular physical activity. The aim of this study was to evaluate the diagnostic utility of CMR in athletes with suspected structural heart disease (SHD) and to analyse the relation between the coexistence of AH and SHD. We wanted to assess whether the presence of AH phenotype could be considered as a sign of a healthy heart less prone to development of SHD. This retrospective, single centre study included 154 consecutive athletes (57 non-amateur, all sports categories, 87% male, mean age 34 ± 12 years) referred for CMR because of suspected SHD. The suspicion was based on existing guidelines including electrocardiographic and/or echocardiographic changes suggestive of abnormality but without a formal diagnosis. CMR permitted establishment of a new diagnosis in 66 patients (42%). The main diagnoses included myocardial fibrosis typical for prior myocarditis (n = 21), hypertrophic cardiomyopathy (n = 17, including 6 apical forms), other cardiomyopathies (n = 10) and prior myocardial infarction (n = 6). Athlete's heart was diagnosed in 59 athletes (38%). The presence of pathologic late gadolinium enhancement (LGE) was found in 41 patients (27%) and was not higher in athletes without AH (32% vs. 19%, p = 0.08). Junction-point LGE was more prevalent in patients with AH phenotype (22% vs. 9%, p = 0.02). Patients without AH were not more likely to be diagnosed with SHD than those with AH (49% vs. 32%, p = 0.05). Based on the results of CMR and other tests, three patients (2%) were referred for ICD implantation for the primary prevention of sudden cardiac death with one patient experiencing adequate intervention during follow-up. The inclusion of CMR into the diagnostic process leads to a new diagnosis in many athletes with suspicion of SHD and equivocal routine tests. Athletes with AH pattern are equally likely to be diagnosed with SHD in comparison to those without AH phenotype. This shows that the development of AH and SHD can occur in parallel, which makes differential diagnosis in this group of patients more challenging.

Role of cardiac magnetic resonance in heart failure of initially unknown etiology: A 10-year observational study.

BACKGROUND: The heart failure (HF) population is estimated to be 64.3 million people worldwide and continues to grow. Identifying the underlying cause of HF is crucial for patient management and prognosis. AIMS: We sought to evaluate the role of cardiac magnetic resonance (CMR) imaging to identify the etiology of HF and to evaluate the impact of CMR on diagnosis and patient management. METHODS: We retrospectively reviewed the medical charts of 8630 consecutive patients referred for CMR in a large tertiary center between 2008 and 2017 (10 years). In this study, we only included patients referred for CMR due to HF of unknown etiology whose diagnostic workup had not revealed suspicion of any specific cardiac disease leading to HF. We also analyzed changes in patient management that were guided by the CMR findings, which were defined as changes in treatment and/or the necessity of further tests. RESULTS: The study sample included 243 patients: 173 (71.2%) patients were male, and the mean (SD) age was 44.0 (15.2) years. All patients underwent contrast-enhanced CMR. Late gadolinium enhancement (LGE) was detected in 74.9% of cases. In 94 patients (38.7%), CMR led to a new diagnosis. In 41 patients (16.9%), patient management was changed by CMR. The latter group comprised patients with coronary artery disease, amyloidosis, valvular disease, and cardiomyopathies other than dilated, namely hypertrophic, restrictive, and left ventricular noncompaction. CONCLUSIONS: Our study strongly suggests that CMR imaging is a valuable tool for determining the etiology of HF and affects patient management.

Comparison of mitral regurgitation severity assessments based on magnetic resonance imaging and echocardiography in patients with hypertrophic cardiomyopathy.

Mitral regurgitation (MR), which is one of the factors responsible for heart failure symptoms and the development of atrial fibrillation, is an important feature of hypertrophic cardiomyopathy (HCM), and its presence affects which treatment options are chosen. Although cardiac magnetic resonance imaging (MRI) is considered the reference standard for assessing the regurgitant volume (RV) and fraction (RF), echocardiography is the most common method for assessing MR severity. Accordingly, the aim of this study was to compare the results of echocardiography and cardiac MRI for assessing MR severity in a cohort of patients with HCM. MR severity was assessed in 53 patients using cardiac MRI by determining the mitral RV (MRV) and mitral RF (MRF). The results were graded according to thresholds recommended in current guidelines. MR severity assessed by echocardiography was graded by integrating indices of severity. Greater than mild MR, as assessed using echocardiography, was present in 22 patients (41.5%) with HCM and in none of the control patients (p = 0.001). In all, 31 patients (58.5%) had no more than mild MR. When MR severity was assessed using different methods, either moderate (kappa = 0.44, 95% confidence interval = 0.21-0.67), poor or no agreement was found between MRI-derived and echocardiography-derived grades. HCM patients with echocardiography-derived moderate and severe MR had similar median MRVs and MRFs (p = 0.59 and p = 0.11, respectively). In HCM patients, cardiac MRI and echocardiography were at most in modest agreement in assessing MR severity. Importantly, echocardiography-derived moderate and severe MR were not distinguishable by either MRV or MRF.

Cardiovascular Magnetic Resonance in Peripartum Cardiomyopathy: Comparison with Idiopathic Dilated Cardiomyopathy.

BACKGROUND: Peripartum (PPCM) and dilated (DCM) cardiomyopathies are distinct forms of cardiac disease that share certain aspects in clinical presentation. AIM: We hypothesized that different cardiac structural changes underlie PPCM and DCM, and we aimed to investigate them with cardiovascular magnetic resonance (CMR). METHODS: We included 21 PPCM patients (30.5 ± 5.9 years) and 30 female DCM patients (41.5 ± 16.8 years) matched for left ventricular ejection fraction. Biventricular and biatrial volumetric and functional parameters were assessed along with ventricular and atrial strain indices based on feature-tracking techniques. The presence of late gadolinium enhancement (LGE) was also assessed. RESULTS: In PPCM, the left ventricular (LV) stroke volume index was lower (p = 0.04), right atrial (RA) minimal and pre-systolic volumes were higher (p < 0.01 and p = 0.02, respectively), and the total RA ejection fraction was lower (p = 0.02) in comparison to DCM. Moreover, in PPCM, the LV global longitudinal strain (p = 0.03), global circumferential strain rate (p = 0.04), and global longitudinal strain rate (p < 0.01) were less impaired than in DCM. Both PPCM and DCM patients with LGE had more dilated ventricles and more impaired LV and left atrial function than in PPCM and DCM patients without LGE. CONCLUSIONS: Subtle differences appear on CMR between PPCM and DCM. Most importantly, the RA is larger and more impaired, and LV global longitudinal strain is less reduced in PPCM than in DCM. Furthermore, similarly to DCM, PPCM patients with LGE have more dilated and impaired ventricles than patients without LGE.

Comprehensive leaf size traits dataset for seven plant species from digitised herbarium specimen images covering more than two centuries.

BACKGROUND: Morphological leaf traits are frequently used to quantify, understand and predict plant and vegetation functional diversity and ecology, including environmental and climate change responses. Although morphological leaf traits are easy to measure, their coverage for characterising variation within species and across temporal scales is limited. At the same time, there are about 3100 herbaria worldwide, containing approximately 390 million plant specimens dating from the 16th to 21st century, which can potentially be used to extract morphological leaf traits. Globally, plant specimens are rapidly being digitised and images are made openly available via various biodiversity data platforms, such as iDigBio and GBIF. Based on a pilot study to identify the availability and appropriateness of herbarium specimen images for comprehensive trait data extraction, we developed a spatio-temporal dataset on intraspecific trait variability containing 128,036 morphological leaf trait measurements for seven selected species. NEW INFORMATION: After scrutinising the metadata of digitised herbarium specimen images available from iDigBio and GBIF (21.9 million and 31.6 million images for Tracheophyta; accessed date December 2020), we identified approximately 10 million images potentially appropriate for our study. From the 10 million images, we selected seven species (Salix bebbiana Sarg., Alnus incana (L.) Moench, Viola canina L., Salix glauca L., Chenopodium album L., Impatiens capensis Meerb. and Solanum dulcamara L.) , which have a simple leaf shape, are well represented in space and time and have high availability of specimens per species. We downloaded 17,383 images. Out of these, we discarded 5779 images due to quality issues. We used the remaining 11,604 images to measure the area, length, width and perimeter on 32,009 individual leaf blades using the semi-automated tool TraitEx. The resulting dataset contains 128,036 trait records.We demonstrate its comparability to trait data measured in natural environments following standard protocols by comparing trait values from the TRY database. We conclude that the herbarium specimens provide valuable information on leaf sizes. The dataset created in our study, by extracting leaf traits from the digitised herbarium specimen images of seven selected species, is a promising opportunity to improve ecological knowledge about the adaptation of size-related leaf traits to environmental changes in space and time.

Deformation Parameters of the Heart in Endurance Athletes and in Patients with Dilated Cardiomyopathy-A Cardiac Magnetic Resonance Study.

A better understanding of the left ventricle (LV) and right ventricle (RV) functioning would help with the differentiation between athlete's heart and dilated cardiomyopathy (DCM). We aimed to analyse deformation parameters in endurance athletes relative to patients with DCM using cardiac magnetic resonance feature tracking (CMR-FT). The study included males of a similar age: 22 ultramarathon runners, 22 patients with DCM and 21 sedentary healthy controls (41 ± 9 years). The analysed parameters were peak LV global longitudinal, circumferential and radial strains (GLS, GCS and GRS, respectively); peak LV torsion; peak RV GLS. The peak LV GLS was similar in controls and athletes, but lower in DCM (p < 0.0001). Peak LV GCS and GRS decreased from controls to DCM (both p < 0.0001). The best value for differentiation between DCM and other groups was found for the LV ejection fraction (area under the curve (AUC) = 0.990, p = 0.0001, with 90.9% sensitivity and 100% specificity for ≤53%) and the peak LV GRS diastolic rate (AUC = 0.987, p = 0.0001, with 100% sensitivity and 88.4% specificity for >-1.27 s-1). The peak LV GRS diastolic rate was the only independent predictor of DCM (p = 0.003). Distinctive deformation patterns that were typical for each of the analysed groups existed and can help to differentiate between athlete's heart, a nonathletic heart and a dilated cardiomyopathy.

Sudden cardiac death risk in hypertrophic cardiomyopathy: comparison between echocardiography and magnetic resonance imaging.

In hypertrophic cardiomyopathy (HCM) patients, left ventricular (LV) maximal wall thickness (MWT) is one of the most important factors determining sudden cardiac death (SCD) risk. In a large unselected sample of HCM patients, we aimed to simulate what changes would occur in the calculated SCD risk according to the European HCM Risk-SCD calculator when MWT measured using echocardiography was changed to MWT measured using MRI. All consecutive patients with HCM who underwent cardiac MRI were included. MWT measured with echocardiography and MRI were compared, and 5-year SCD risk according to the HCM Risk-SCD calculator was computed using four different models. The final population included 673 patients [389 (57.8%) males, median age 50 years, interquartile range (36-60)]. The median MWT was lower measured by echocardiography than by MRI [20 (17-24) mm vs 21 (18-24) mm; p < 0.0001]. There was agreement between echocardiography and MRI in the measurement of maximal LV wall thickness in 96 patients (14.3%). The largest differences between echo and MRI were - 13 mm and + 9 mm. The differences in MWT by echocardiography and MRI translated to a maximal difference of 8.33% in the absolute 5-year risk of SCD, i.e., the echocardiography-based risk was 8.33% lower than the MRI-based estimates. Interestingly, 13.7% of patients would have been reclassified into different SCD risk categories if MRI had been used to measure MWT instead of echocardiography. In conclusion, although there was high general intermodality agreement between echocardiography and MRI in the MWT measurements, the differences in MWT translated to significant differences in the 5-year risk of SCD.

Cardiac involvement in consecutive elite athletes recovered from Covid-19: A magnetic resonance study.

Magnetic resonance (MR) studies suggested cardiac involvement post-Covid-19 in a significant subset of affected individuals, including athletes. This brings serious clinical concerns regarding the potential need for in-depth cardiac screening in athletes after Covid-19 before return to play. The aim of this study was to gain further insight into the relation between Covid-19 and cardiac involvement in professional athletes. This was a retrospective cohort study, in which 26 consecutive elite athletes (national team, Olympians, top national league players; median age 24 years, interquartile range [IQR] 21-27, 81% female) were included. At 1.5 T including balanced steady-state free precession cine imaging, T1 and T2-mapping using Myomaps software (Siemens), dark-blood T2-weighted images with fat suppression, and late gadolinium enhancement (LGE) with phase-sensitive inversion recovery sequence were used. The athletes had mainly asymptomatic or mild course of the disease (77%). They were scanned after a median of 32 days (IQR 22-62 days) from the diagnosis. MR data were reviewed by three independent observers, each with >10 years cardiac MR experience. Native T1, T2, extracellular volume, and T2 signal intensity ratio were calculated. Diagnosis of acute myocarditis was based on modified Lake Louise criteria. Statistical analyses used were Pearson correlation and Bland-Altman repeatability analysis. At the time of MR the athletes had no pathologic electrocardiogram abnormalities or elevated troponin levels. MR did not reveal any case of acute myocarditis. Cardiac abnormalities were found in five (19%) athletes, including four athletes presenting borderline signs of isolated myocardial edema and one athlete showing nonischemic LGE with pleural and pericardial effusion. Another athlete had signs of persistent lung congestion without cardiac involvement. We have shown that in a small group of elite athletes with mainly asymptomatic to mild Covid-19, lack of electrocardiographic changes, and normal troponin concentration 1-2 months after the diagnosis, there were no signs of acute myocarditis, but 19% of athletes had some abnormalities as assessed by cardiac MR. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 3.

Impact of cardiac magnetic resonance on the diagnosis of hypertrophic cardiomyopathy - a 10-year experience with over 1000 patients.

OBJECTIVES: To assess the value of cardiac MRI in comparison to echocardiography in consecutive patients with previously diagnosed and new suspected hypertrophic cardiomyopathy (HCM). METHODS: All MRI studies of patients with HCM or suspected disease performed at our centre within a 10-year time period were evaluated. Initial diagnoses (echocardiography-based) and final (MRI-based) diagnoses were compared in subgroups, and the discrepancies were recorded. RESULTS: A total of 1006 subjects with HCM or suspected HCM were identified (61% males, 39% females; median age, 49.1 years; interquartile range, 34.9-60.4). In 12 (2.2%) out of 550 patients with known HCM, MRI indicated a diagnosis other than HCM, including but not limited to the subaortic membrane (n = 1, 8.3%) or mild left ventricular hypertrophy (n = 5, 41.7%). Among all patients with suspected HCM (n = 456), MRI diagnosis was different from HCM in 5.3% (n = 24) of patients. In an additional 20.4% of patients (n = 93), no significant hypertrophy was present. In total, among patients with suspected HCM, MRI led to clear HCM diagnosis in 204 (44.7%) patients. Among patients with a history of uncontrolled hypertension suspected of having HCM, MRI aided in identifying cardiomyopathy in 47.9% of patients. This subgroup contained the largest proportion of patients with an ambiguous diagnosis, namely, 29.6% compared with 13.8% in the remaining groups of patients with suspected HCM (p = 0.0001). CONCLUSIONS: In a small but important group of patients with ultrasound-based HCM, cardiac MRI can diagnose previously unknown conditions and/or refute suspected cardiomyopathy. The diagnostic yield of MRI when compared to echocardiography in patients suspected of having HCM is 44.7%. KEY POINTS: • Out of 550 patients previously diagnosed with echocardiography but without magnetic resonance imaging (MRI) as having hypertrophic cardiomyopathy (HCM), we diagnosed a different disease in 12 (2.2%) patients using MRI. • Among patients with suspected HCM based on echocardiography, MRI led to clear HCM diagnosis in 44.7% of patients. • In patients with a history of uncontrolled hypertension suspected, based on an echocardiogram, of having HCM, MRI aided in identifying cardiomyopathy in 47.9% of patients. This subgroup contained the largest proportion of patients with an ambiguous diagnosis.

Prognostic role of PET/MRI hybrid imaging in patients with pulmonary arterial hypertension.

OBJECTIVE: Right ventricular (RV) function is a major determinant of survival in patients with pulmonary arterial hypertension (PAH). Metabolic alterations may precede haemodynamic and clinical deterioration. Increased RV fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) was recently associated with progressive RV dysfunction in MRI, but the prognostic value of their combination has not been established. METHODS: Twenty-six clinically stable patients with PAH (49.9±15.2 years) and 12 healthy subjects (control group, 44.7±13.5 years) had simultaneous PET/MRI scans. FDG uptake was quantified as mean standardised uptake value (SUV) for both left ventricle (LV) and RV. Mean follow-up time of this study was 14.2±7.3 months and the clinical end point was defined as death or clinical deterioration. RESULTS: Median SUVRV/SUVLV ratio was 1.02 (IQR 0.42-1.21) in PAH group and 0.16 (0.13-0.25) in controls, p<0.001. In PAH group, SUVRV/SUVLV significantly correlated with RV haemodynamic deterioration. In comparison to the stable ones, 12 patients who experienced clinical end point had significantly higher baseline SUVRV/SUVLV ratio (1.21 (IQR 0.87-1.95) vs 0.53 (0.24-1.08), p=0.01) and lower RV ejection fraction (RVEF) (37.9±5.2 vs 46.8±5.7, p=0.03). Cox regression revealed that SUVRV/SUVLV ratio was significantly associated with the time to clinical end point. Kaplan-Meier analysis showed that combination of RVEF from MRI and SUVRV/SUVLV assessment may help to predict prognosis. CONCLUSIONS: Increased RV glucose uptake in PET and decreased RVEF identify patients with PAH with worse prognosis. Combining parameters from PET and MRI may help to identify patients at higher risk who potentially benefit from therapy escalation, but this hypothesis requires prospective validation.

The impact of pulmonary regurgitation on right ventricular size and function in patients with repaired tetralogy of Fallot and additional haemodynamic abnormalities.

PURPOSE: Right ventricular (RV) outflow tract obstruction (RVOTO) was demonstrated to be protective against RV dilatation in patients with repaired tetralogy of Fallot and chronic pulmonary regurgitation (PR). We hypothesised that the presence of additional haemodynamic abnormalities (more than mild tricuspid regurgitation, residual ventricular septal defect) reduces this protective association. Accordingly, we aimed to assess the impact of PR on RV size and function in this population. MATERIAL AND METHODS: Consecutive patients with additional haemodynamic abnormalities after tetralogy of Fallot (TOF) repair, who had undergone cardiovascular magnetic resonance, were included. RESULTS: Out of 90 patients studied, 18 individuals (mean age 32.5 ± 10.7 years, 72.2% males) met the inclusion criteria. There were no differences in RV volumes and ejection fraction between patients with and without RVOTO. Neither PR fraction (PRF) nor PR volume (PRV) correlated with RV end-diastolic volume (r = 0.36; p = 0.15 and r = 0.37; p = 0.14, respectively, for PRF and PRV) or RV end-systolic volume (r = 0.2; p = 0.42 and r = 0.19; p = 0.45, respectively, for PRF and PRV). Similarly, no significant correlations were observed between PRF or PRV and RV ejection fraction (r = -0.04; p = 0.87 and r = -0.03; p = 0.9, respectively). CONCLUSIONS: Additional haemodynamic abnormalities are associated with the abolition of the protective effect of RVOTO on RV size. There was no significant relationship between measures of PR and RV volumes in patients after TOF repair with concomitant haemodynamic abnormalities. These abnormalities acted as confounding factors in the assessment of the impact of pulmonary regurgitation on RV size and function.

Predictors of right ventricular function and size in patients with hypertrophic cardiomyopathy.

We investigated factors associated with right ventricular (RV) function and size in hypertrophic cardiomyopathy (HCM) patients. Two hundred fifty-three consecutive HCM patients and 20 healthy volunteers underwent cardiac magnetic resonance examination. In addition to measuring RV function (ejection fraction-RVEF) and size (end-diastolic volume-RVEDV), each image was inspected for the presence of RV and left ventricular (LV) hypertrophy, and the maximal wall thickness of the left and right ventricles was recorded. HCM patients had higher RVEF and lower RVEDV than healthy volunteers and similar RV mass. The mean RV wall thickness was higher in HCM patients than in controls. LV late gadolinium enhancement (LGE) was present in 89.7% of patients, and RV LGE was present in 3.1% of patients (p < 0.0001). Univariate and multivariable analyses revealed that LVEF, peak LV outflow tract gradient, LV LGE, maximal LV wall thickness, and tricuspid regurgitation (TR) volume by magnetic resonance imaging were positive predictors of RVEF. In addition to TR volume, the only independent predictor of RVEF < 45% was LVEF (odds ratio = 0.80, 95% confidence interval 0.67-0.95). Multivariable analysis revealed that LVEDV and TR volume were positive predictors of RVEDV, whereas negative predictors were RVEF, maximal RV wall thickness, LV LGE, and age. Neither estimated systolic pulmonary artery pressure nor TR grade by echocardiography proved to be predictors of RVEF. There were no differences in either the maximal RV wall thickness or the maximal left ventricular (LV) wall thickness in patients stratified according to NYHA functional class (p = 0.93 and p = 0.15, respectively). There were no differences in mean RV wall thickness in patients categorised based on the number of clinical risk factors for sudden cardiac death (SCD), i.e., non-sustained ventricular tachycardia, family history of SCD, or unexplained syncope (p = 0.79). On the other hand, there was a weak positive association between RV hypertrophy and the estimated probability of SCD at 5 years (rho = 0.16, p = 0.01). RV systolic dysfunction measured as decreased RVEF was uncommon in HCM and was associated with poor LV systolic function. LV also had a significant impact on RV size.

Safety of regadenoson with theophylline reversal during dynamic computed tomography perfusion and magnetic resonance imaging in patients with coronary artery disease.

BACKGROUND: The use of regadenoson in dynamic computed tomography perfusion (CTP) and magnetic resonance myocardial perfusion imaging (MR MPI) is off­label. AIMS: The study aimed to assess the safety of regadenoson with theophylline reversal during CTP and MR MPI in patients with coronary artery disease (CAD). METHODS: In this prospective study, patients with 1 or more intermediate coronary artery stenoses on computed tomography angiography underwent CTP and MR MPI with 0.4 mg of regadenoson. After examinations, 200 mg of theophylline was given intravenously in 100 ml of saline. Changes in blood pressure (BP) and heart rate (HR) were repeatedly assessed. All side effects and adverse events were recorded. RESULTS: Out of 106 examinations in 53 patients (25 females, 63.5 [8.5] years), all were diagnostic. There were no deaths, myocardial infarctions, severe arrhythmias, high­grade atrioventricular blocks, or bronchospasms. The most common symptoms were palpitations (17%), hot flushing (8%), chest discomfort (4%), and mild dyspnea (3%). There were no differences between baseline and peak BP. There was an increase in median (interquartile range) peak HR after regadenoson as compared with baseline (MR MPI, 63 [59-75] bpm vs 93 [86-102] bpm; P <0.001; and CTP, 65 [60-70] bpm vs 95 [86-107] bpm; P <0.001). The hemodynamic response to regadenoson and its side effects were completely reversible by theophylline. CONCLUSIONS: Regadenoson may be a safe vasodilator for CTP and MR MPI in patients with CAD. The administration of theophylline after perfusion is safe and reverses side effects of regadenoson.

Factors associated with the need for pulmonary valve replacement in asymptomatic patients with isolated pulmonary regurgitation after repair of tetralogy of Fallot: a cardiac magnetic resonance study.

BACKGROUND: Pulmonary regurgitation (PR) is the most common late complication in patients after repair of tetralogy of Fallot (TOF). Most patients remain asymptomatic over years, but eventually, the compensatory mechanisms fail, leading to right ventricular (RV) dilation and dysfunction, limited exercise capacity, ventricular arrhythmia, and sudden death. AIMS: We aimed to evaluate associations between cardiac magnetic resonance (CMR) parameters and the need for either surgical or percutaneous pulmonary valve replacement (PVR) in asymptomatic patients with significant PR after repair of TOF. METHODS: Of 209 patients with repaired TOF who had undergone a CMR study, we selected 61 asymptomatic patients with moderate­to­severe PR and followed them for up to 4 years (mean [SD], 21.4 [13.7] months). We excluded patients with residual ventricular septal defect, a peak RV outflow tract gradient of 30 mm Hg or higher, or at least moderate tricuspid regurgitation. RESULTS: Receiver operating characteristic curve analyses revealed that the ratio of RV to left ventricular (LV) volume (RV/ LV ratio; threshold >2.4) and PR fraction (PRF; threshold >33%) had acceptable discriminatory capacity to differentiate between patients requiring PVR and those treated conservatively. The Cox proportional hazards regression and the Kaplan­Meier curves revealed that the RV / LV ratio and PRF was significantly associated with the need for PVR. The combination of the RV / LV ratio and PRF provided significant discrimination in terms of survival without PVR (P <0.001; log­rank test for trend). CONCLUSIONS: The RV/ LV ratio and PRF were significantly associated with the need for PVR in asymptomatic patients with isolated moderate­to­severe PR after repair of TOF.

Regadenoson dynamic computed tomography myocardial perfusion using low-dose protocol for evaluation of the ischemic burden. ULYSSES study.

BACKGROUND: The purpose of this study was to assess the feasibility of low-dose dynamic regadenoson computed tomography perfusion (CTP) protocol, and to determine which parameters provide the best diagnostic yield for the presence and burden of ischemia in reference to the magnetic resonance myocardial perfusion imaging (MR MPI). METHODS: Fifty six patients with ≥1 intermediate (50-90%) coronary artery stenosis on CTA underwent dynamic stress CTP and MR MPI. The distribution of contrast agent in CTP was represented for each myocardial segment as either absolute or indexed: myocardial blood flow (MBF), myocardial blood volume (MBV), perfused capillary blood volume (PCBV), peak value (PV), time to peak (TTP), respectively. RESULTS: Of 56 patients (25 females, 63.5 ± 8.5y), 15 (27%) were diagnosed with reversible ischemia and 3 (5%) with fixed ischemia on the MR MPI. The median radiation dose for dynamic CTP scan was 352.00 [276.4-496.6] mGy*cm. The optimal cut-off point for the prediction of reversible ischemia on MR MPI for the absolute parameters were: MBF ≤156.49 (AUC=0.899), MBV ≤15.06 (AUC=0.901), PCBV ≤7.90 (AUC=0.880), PV ≤ 88.30 (AUC=0.766), TTP ≥22.58 (AUC=0.595); and for the indexed: indexed MBF ≤0.78 (AUC=0.926), indexed MBV ≤0.81 (AUC=0.924), indexed PCBV ≤0.70 (AUC=0.894); indexed PV ≤ 0.79 (AUC=0.869), indexed TTP ≤0.87 (AUC=0.685). The best parameters for ischemia detection were indexed MBF and indexed MBV, with sensitivities 91% and 89%, specificities 97% and 96%, NPV 99% and 99%, PPV 76% and 69%, and accuracies 96% and 95%, respectively. In per patient analysis, indexed MBF correlated significantly better with the ischemia burden than any of the absolute parameters (p < 0.01 for all comparisons). CONCLUSIONS: Regadenoson dynamic CTP using low-dose protocol is feasible while maintaining high diagnostic accuracy. The best diagnostic value may be provided by indexed parameters, of which indexed MBF and indexed MBV may provide best incremental value in identification of the presence and burden of ischemia.

Quantification of mitral regurgitation in patients with hypertrophic cardiomyopathy using aortic and pulmonary flow data: impacts of left ventricular outflow tract obstruction and different left ventricular segmentation methods.

BACKGROUND: Cardiovascular magnetic resonance (CMR) imaging in patients with hypertrophic cardiomyopathy (HCM) enables the assessment of not only left ventricular (LV) hypertrophy and scarring but also the severity of mitral regurgitation. CMR assessment of mitral regurgitation is primarily based on the difference between LV stroke volume (LVSV) and aortic forward flow (Ao) measured using the phase-contrast (PC) technique. However, LV outflow tract (LVOT) obstruction causing turbulent, non-laminar flow in the ascending aorta may impact the accuracy of aortic flow quantification, leading to false conclusions regarding mitral regurgitation severity. Thus, we decided to quantify mitral regurgitation in patients with HCM using Ao or, alternatively, main pulmonary artery forward flow (MPA) for mitral regurgitation volume (MRvol) calculations. METHODS: The analysis included 143 prospectively recruited subjects with HCM and 15 controls. MRvol was calculated as the difference between LVSV computed with either the inclusion (LVSVincl) or exclusion (LVSVexcl) of papillary muscles and trabeculations from the blood pool and either Ao (MRvolAoi or MRvolAoe) or MPA (MRvolMPAi or MRvolMPAe). The presence or absence of LVOT obstruction was determined based on Doppler echocardiography findings. RESULTS: MRvolAoi was higher than MRvolMPAi in HCM patients with LVOT obstruction [47.0 ml, interquartile range (IQR) = 31.5-60.0 vs. 35.5 ml, IQR = 26.0-51.0; p < 0.0001] but not in non-obstructive HCM patients (23.0 ml, IQR = 16.0-32.0 vs. 24.0 ml, IQR = 15.3-32.0; p = 0.26) or controls (18.0 ml, IQR = 14.3-21.8 vs. 20.0 ml, IQR = 14.3-22.0; p = 0.89). In contrast to controls and HCM patients without LVOT obstruction, in HCM patients with LVOT obstruction, aortic flow-based MRvol (MRvolAoi) was higher than pulmonary-based findings (MRvolMPAi) (bias = 9.5 ml; limits of agreement: -11.7-30.7 with a difference of 47 ml in the extreme case). The differences between aortic-based and pulmonary-based MRvol values calculated using LVSVexcl mirrored those derived using LVSVincl. However, MRvol values calculated using LVSVexcl were lower in all the groups analyzed (HCM with LVOT obstruction, HCM without LVOT obstruction, and controls) and with all methods of MRvol quantification used (p ≤ 0.0001 for all comparisons). CONCLUSIONS: In HCM patients, LVOT obstruction significantly affects the estimation of aortic flow, leading to its underestimation and, consequently, to higher MRvol values than those obtained with MPA-based MRvol calculations.

What is the optimal anatomic location for coronary artery pressure measurement at CT-derived FFR?

BACKGROUND: CT-FFR is an area of growing interest in the field of cardiac imaging. However, the specific anatomic location distal to a lesion of interest where CT-FFR should be computed to yield the most valid results has not been examined. This study investigated the most appropriate anatomic location distal to a coronary artery stenosis for obtaining CT-FFR measurements. METHODS: 73 patients (60 ± 9 years; 58% male) with at least one coronary lesion with 40-90% stenosis on coronary CTA (either a 2 × 128 slice or a 2 × 192 slice dual-source CT scanner) underwent stress cardiac magnetic resonance (CMR) perfusion imaging for inducible ischemia. 133 coronary arteries and corresponding myocardial territories were analyzed. The most appropriate anatomic location for predicting lesion-specific ischemia via CT-FFR (cFFR version 1.4, Siemens) was determined as either the distance from the lesion of interest or as a multiple of the reference vessel diameter distal to the minimum lumen area (MLA). RESULTS: Inducible myocardial ischemia was found on MRI in 24 (18.1%) vessels/corresponding myocardial territories. The area under the ROC curve was A) 0.866 for CT-FFR measurement locations distal to the MLA expressed as a multiple of the reference diameter, B) 0.854 when expressed as a distance (mm) distal to the MLA, C) 0.803 for CT-FFR values measured in the distal vessel, and D) 0.725 according to stenosis severity on coronary CTA (A vs B p = 0.093; A vs D p = 0.003; A vs C p = 0.019; B vs D p = 0.006; B vs C p = 0.061; C vs D p = 0.082). The most optimal thresholds for agreement of CT-FFR with the reference CMR perfusion were at 41 mm or 10.9 times the proximal reference diameter distal to the MLA. CONCLUSIONS: Our results suggest that the best agreement of CT-FFR with the reference CMR perfusion study is provided when CT-FFR values are computed at 41 mm or 10.9 times the proximal reference diameter distal to the MLA.