Collinearity and Dimensionality Reduction in Radiomics: Effect of Preprocessing Parameters in Hypertrophic Cardiomyopathy Magnetic Resonance T1 and T2 Mapping.

Radiomics and artificial intelligence have the potential to become a valuable tool in clinical applications. Frequently, radiomic analyses through machine learning methods present issues caused by high dimensionality and multicollinearity, and redundant radiomic features are usually removed based on correlation analysis. We assessed the effect of preprocessing-in terms of voxel size resampling, discretization, and filtering-on correlation-based dimensionality reduction in radiomic features from cardiac T1 and T2 maps of patients with hypertrophic cardiomyopathy. For different combinations of preprocessing parameters, we performed a dimensionality reduction of radiomic features based on either Pearson's or Spearman's correlation coefficient, followed by the computation of the stability index. With varying resampling voxel size and discretization bin width, for both T1 and T2 maps, Pearson's and Spearman's dimensionality reduction produced a slightly different percentage of remaining radiomic features, with a relatively high stability index. For different filters, the remaining features' stability was instead relatively low. Overall, the percentage of eliminated radiomic features through correlation-based dimensionality reduction was more dependent on resampling voxel size and discretization bin width for textural features than for shape or first-order features. Notably, correlation-based dimensionality reduction was less sensitive to preprocessing when considering radiomic features from T2 compared with T1 maps.

Image resampling and discretization effect on the estimate of myocardial radiomic features from T1 and T2 mapping in hypertrophic cardiomyopathy.

Radiomics is emerging as a promising and useful tool in cardiac magnetic resonance (CMR) imaging applications. Accordingly, the purpose of this study was to investigate, for the first time, the effect of image resampling/discretization and filtering on radiomic features estimation from quantitative CMR T1 and T2 mapping. Specifically, T1 and T2 maps of 26 patients with hypertrophic cardiomyopathy (HCM) were used to estimate 98 radiomic features for 7 different resampling voxel sizes (at fixed bin width), 9 different bin widths (at fixed resampling voxel size), and 7 different spatial filters (at fixed resampling voxel size/bin width). While we found a remarkable dependence of myocardial radiomic features from T1 and T2 mapping on image filters, many radiomic features showed a limited sensitivity to resampling voxel size/bin width, in terms of intraclass correlation coefficient (> 0.75) and coefficient of variation (< 30%). The estimate of most textural radiomic features showed a linear significant (p < 0.05) correlation with resampling voxel size/bin width. Overall, radiomic features from T2 maps have proven to be less sensitive to image preprocessing than those from T1 maps, especially when varying bin width. Our results might corroborate the potential of radiomics from T1/T2 mapping in HCM and hopefully in other myocardial diseases.

Ventricular tachycardia ablation guided or aided by scar characterization with cardiac magnetic resonance: rationale and design of VOYAGE study.

BACKGROUND: Radiofrequency ablation has been shown to be a safe and effective treatment for scar-related ventricular arrhythmias (VA). Recent preliminary studies have shown that real time integration of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) images with electroanatomical map (EAM) data may lead to increased procedure efficacy, efficiency, and safety. METHODS: VOYAGE is a prospective, randomized, multicenter controlled open label study designed to compare in terms of efficacy, efficiency, and safety a CMR aided/guided workflow to standard EAM-guided ventricular tachycardia (VT) ablation. Patients with an ICD or with ICD implantation expected within 1 month, with scar related VT, suitable for CMR and multidetector computed tomography (MDCT) will be randomized to a CMR-guided or CMR-aided approach, whereas subjects unsuitable for imaging or with image quality deemed not sufficient for postprocessing will be allocated to standard of care ablation. Primary endpoint is defined as VT recurrences (sustained or requiring appropriate ICD intervention) during 12 months follow-up, excluding the first month of blanking period. Secondary endpoints will include procedural efficiency, safety, impact on quality of life and comparison between CMR-guided and CMR-aided approaches. Patients will be evaluated at 1, 6 and 12 months. DISCUSSION: The clinical impact of real time CMR-guided/aided ablation approaches has not been thoroughly assessed yet. This study aims at defining whether such workflow results in more effective, efficient, and safer procedures. If proven to be of benefit, results from this study could be applied in large scale interventional practice. Trial registrationClinicalTrials.gov, NCT04694079, registered on January 1, 2021.

Incidence of Pericardial Effusion in Patients with Advanced Non-Small Cell Lung Cancer Receiving Immunotherapy.

INTRODUCTION: Cardiovascular toxicity of immunotherapy represents an underreported but potentially fatal side effect. A relatively high incidence of pericardial disease has been noticed in patients with non-small cell lung cancer (NSCLC). METHODS: We retrospectively analyzed a population of patients with advanced NSCLC receiving immune checkpoint inhibitors (ICIs) looking for the presence of pericardial effusion at baseline or during treatment. The study population was compared with a control group treated with chemotherapy. All patients were checked for the presence of concomitant pleural effusion. RESULTS: We identify 60 patients (36 male/24 female, median age 70 years [range 43-81]). Prevalent histology was adenocarcinoma (65%) followed by squamous cell carcinoma (28%) and large cell or not otherwise specified (NOS) carcinoma (7%). Treatment consisted of nivolumab 3 mg/kg every 14 days (52 cases; 45 as second-line and 7 as third-line treatment) or pembrolizumab 200 mg (8 cases; all first-line treatment) for a total of 302 cycles delivered. Four out of 60 patients (6.7%) developed pericardial effusion during treatment, in two cases (3.3%) without concomitant pleural effusion, compared to 2 out of 60 (3.3%) in the control group in one case without concomitant pleural effusion (1.6%). Median time of onset was 40 days. Myocarditis was not observed. CONCLUSION: Our findings confirm pericardial effusion as a relatively frequent side effect of immunotherapy in NSCLC. Clinicians should be aware of this specific toxicity in patients with metastatic NSCLC receiving immunotherapy and refer to a cardiologist for a multidisciplinary approach.

Cardiovascular Risk Factors and Timing of Anthracyclines and Trastuzumab Cardiac Toxicity.

BACKGROUND/AIM: Cardiovascular risk factors (CVRFs) predict cardiotoxicity in cancer patients but their role in late cardiac toxicity is less clear. PATIENTS AND METHODS: This was a retrospective analysis of patients treated with anthracyclines (A) and/or trastuzumab (T) and a correlation with early (≤5 years) or late (>5 years) cardiac toxicity, and baseline CVRFs and CVRFs at toxicity time. RESULTS: A total of 610 patients were included, 422 with (Group A) and 188 without (Group B) baseline CVRFs. In group A toxicity incidence was 4.7% with all events during treatment or immediately after [mean onset time 0.7 years (range=0.2-1.6)]. Events rate was 3.2% in group B with all events after five years [mean time onset 6.9 years (range=5.2-7.5)]. All group B patients who developed late cardiac toxicity presented with CVRFs at the time of toxicity not reported before. CONCLUSION: CVRFs could predict late cardiac toxicity and their control should be part of the survivorship program.

Diagnostic and Prognostic Role of Cardiac Magnetic Resonance Before Implantable Cardioverter Defibrillator.

The use of cardiac magnetic resonance (cMR) to assess remodeling and tissue characterization in primitive and secondary cardiomyopathies has progressively increased, and it carries important prognostic informations. The aim of this study was to assess the overall clinical value of cMR before implantable cardioverter defibrillator (ICD). All patients referred to our center for an ICD implantation and submitted to cMR (n = 134) were analyzed. All the cMR diagnostic findings and following clinical events were reviewed to assess clinical relevance in patients care. The use of cMR before ICD implantation has progressively increased during the decade studied (13% to 53%, p <0.001). Subjects who underwent cMR were younger, more often female, with lower NYHA class and higher ejection fraction (p <0.05 for all). Unexpected diagnostic findings were observed in 34 patients (25%), resulting in an immediate therapeutic strategy modification in 13%. A pattern of fibrosis leading to a change in the disease's etiology and thrombus detection were the most frequent cMR findings, followed by anatomical incidental findings. Any grade of fibrosis carried a higher annual incidence of combined death or ventricular arrhythmias (9.92% vs 1.83%, p = 0.02). Annual event rate was related to the extent of scarring. In conclusion, we observed a progressively increase of cMR utilization before ICD implantation during the last decade. This practice has yielded a significant increase of new diagnostic findings, carrying unique prognostic information linked to tissue characterization.

T1 and T2 mapping in the identification of acute myocardial injury in patients with NSTEMI.

AIMS: To test T1 and T2 mapping in the assessment of acute myocardial injury in patients with non-ST-segment elevation myocardial infarction (NSTEMI), evaluated before revascularization. METHODS: Forty-seven patients with acute NSTEMI underwent cardiac magnetic resonance (CMR) at 1.5 T, including T1 and T2 mapping. RESULTS: Coronary angiography (CA) evidenced an obstructive coronary artery disease (CAD) in 36 patients (80%) and a non-obstructive CAD in 11 patients (20%). Edema was detected in 51.1/65.9% of patients in T1/T2 maps, respectively. This difference was due to artifacts in T1 maps. T1/T2 values were significantly higher in the infarcted myocardium (IM) compared with the remote myocardium (RM) (in T1: 1151.6 ± 53.5 ms vs. 958.2 ± 38.6 ms, respectively; in T2: 69 ± 6 ms vs. 51.9 ± 2.9 ms, respectively; p < 0.0001 for both). We found both an obstructive CAD at CA and myocardial edema at CMR in 53.2% of patients, while 8.5% of patients had a non-obstructive CAD and no edema. However, 25.5% of patients had an obstructive CAD without edema, while 12.8% of patients showed edema despite a non-obstructive CAD. Furthermore, in 6 of the edema-positive patients with multi-vessels obstructive CAD, CMR identified myocardial edema in a vascular territory different from that of the lesion supposed to be the culprit at CA. CONCLUSIONS: In a non-negligible percentage of NSTEMI patients, T1 and T2 mapping detect myocardial edema without significant stenosis at CA and vice versa. Therefore, CA and CMR edema imaging might provide complementary information in the evaluation of NSTEMI.

Role of cardiac electronic implantable device in the stratification and management of embolic risk of silent atrial fibrillation: are all atrial fibrillations created equal?

INTRODUCTION: Ischemic strokes may be associated with atrial fibrillation (AF). AF detection is critical in ischemic stroke survivors, often recommending a switch from antiplatelet therapy to oral anticoagulants for secondary prevention. Areas covered: Cardiac implantable electronic devices (CIED) with their long-term recording capability allows to document AF and to quantify the arrhythmia burden. Recent series in pacemaker and implantable cardioverter-defibrillator (ICD) recipients with no prior stroke showed that short episodes of AF increased stroke risk compared with those without AF recorded. Detection of AF by CIEDs represent a unique opportunity for promp prevention of embolic risk in silent AF. It will be attractive to identify AF before a stroke occurs. Expert commentary: The purpose of this article is to review the role of CIED to detect AF, to quantify the role of AF burden, and to guide primary and secondary stroke prevention.

[Application of a shared interdisciplinary and multiprofessional cardio-oncology in-hospital pathway]. / Applicazione di un percorso diagnostico-terapeutico assistenziale di cardioncologia per la rilevazione e la gestione del danno cardiaco da trattamenti oncologici in ambito ospedaliero.

The burden of cardiac side effects in oncology patients will dramatically increase in the near future as a result of the widespread use of anticancer agents affecting the cardiovascular system, the general population aging, the heightened attention in the detection of cardiac toxicity and the absolute gain in terms of overall survival. The relationship between cardiologists and oncologists should therefore be closer leading to the definition of cardio-oncology. The increased number of such patients requires the creation of a dedicated patient assistance program in order to guarantee every patient the possibility of an interdisciplinary and multiprofessional approach. A dedicated care pathway needs a reorganization of internal resources to ensure high standards of care. The proposed pathway is actually active at our institution and has been implemented taking into account available facilities and planned work amount. Our patient cardio-oncology program could be adapted with minimal changes to different hospitals.

Thromboembolic risk and effect of oral anticoagulation according to atrial fibrillation patterns: A systematic review and meta-analysis.

Oral anticoagulation (OAC) is recommended in both paroxysmal atrial fibrillation (pxAF) and nonparoxysmal AF (non-pxAF), but disagreement exists in classes of recommendation. Data on incidence/rate of stroke in pxAF are conflicting, and OAC is often underused in this population. The objectives of the meta-analysis were to investigate different impact on outcomes of pxAF and non-pxAF, with and without OAC. Two reviewers searched for prospective studies on risk of stroke and systemic embolism (SE) in pxAF and non-pxAF, with and without OAC. Quality of evidence was assessed according to GRADE approach. Stroke combined with SE was the main outcome. Meta-regression was performed to evaluate OAC effect on stroke and SE incidence rate. We identified 18 studies. For a total of 239 528 patient-years of follow-up. The incidence rate of stroke/SE was 1.6% (95% confidence interval [CI]: 1.3%-2.0%) in pxAF and 2.3% (95% CI: 2.0%-2.7%) in non-pxAF. Paroxysmal AF was associated with a lower risk of overall thromboembolic (TE) events (risk ratio: 0.72, 95% CI: 0.65-0.80, P < 0.00001) compared with non-pxAF. In both groups, the annual rate of TE events decreased as proportion of patients treated with OAC increased. Non-pxAF showed a reduction from 3.7% to 1.7% and pxAF from 2.5% to 1.2%. Major bleeding rates did not differ among groups. Stroke/SE risk is significantly lower, although clinically meaningful, in pxAF. OAC consistently reduces TE event rates across any AF pattern. As a whole, these data provide the evidence to warrant OAC irrespective of the AF pattern in most (virtually all) patients.

[Teamwork for cardiac imaging: coronary computed tomography angiography and low-dose radiation exposure: a cardiology center experience]. / Teamwork per l'imaging cardiaco: tomografia computerizzata coronarica e bassa dose di esposizione radiologica, esperienza di un centro cardiologico.

BACKGROUND: Multidetector coronary computed tomography angiography (CCTA) is increasingly used for noninvasive imaging of the coronary arteries. Radiation exposure, however, is a potential limitation to a more extensive use of this imaging modality. We aimed to demonstrate that a professional teamwork approach, including a cardiologist and a radiologist in performing CCTA, may allow to obtain best quality exams with very low radiation doses. METHODS: A total of 998 consecutive patients underwent CCTA in accordance with the most recent guidelines. The following procedures were undertaken to reduce the radiation dose: (a) preliminary cardiological evaluation to check for CCTA eligibility; (b) optimized heart rate control with beta-blockers and/or ivabradine; and (c) the use of nonstandardized computed tomography protocols and algorithms for dose reduction. RESULTS: All the patients underwent a preliminary cardiological evaluation; 89% of them were pretreated with oral or intravenous beta-blockers and/or ivabradine; 806 patients (81%) were scanned by means of prospective gating, which allowed a radiation dose exposure of 161 ± 68.64 mGy; 192 patients (19%) underwent a retrospective gating protocol, with a radiation dose exposure of 1135.15 ± 485.87 mGy. In 13 patients (1%) CCTA was uninterpretable because of artifacts. Exam quality was not affected by the use of low-dose computed tomography scanning. Coronary calcium score and/or left ventricular functional analysis were never performed. CONCLUSIONS: The preliminary selection and preparation of patients and optimized scanner utilization allow a substantial reduction in radiation dose for most of the patients submitted to CCTA without affecting image quality. In our experience, a team approach was necessary to allow a "low-dose learning curve" and a progressive reduction in radiation doses administered to patients by means of the prospective gating protocol.

Simultaneous strain-volume analysis by three-dimensional echocardiography: validation in normal subjects with tagging cardiac magnetic resonance.

OBJECTIVE: The aim of this study is to compare three-dimensional echocardiography strain-volume analysis with tagging cardiac magnetic resonance (cMR) measurements. BACKGROUND AND METHODS: Strain-volume analysis represents a noninvasive method to assess myocardial function and volumes simultaneously. It can be derived from echocardiography and speckle-tracking; however, it shows some variability that can limit clinical utilization. A three-dimensional approach partially overcomes these limitations since full-volume acquisition avoids images being foreshortened and geometrical reconstruction. In the study presented here, 23 healthy subjects were studied by three-dimensional echocardiography and cMR during the same session. Images were stored and the better cardiac cycle was chosen for simultaneous analysis of volumes and longitudinal (Long) and circumferential (Circ) strain. By means of full-volume acquisition all parameters can be calculated for each frame of the cardiac cycle using the speckle-tracking method. With cMR, left ventricle volumes were calculated as recommended; myocardial strains were computed in short-axis and long-axis views using the tagging technique. For each patient, volumes and strain values were plotted in a Cartesian system for strain-volume analysis. Data were compared between the two methods using Bland-Altman analysis based on mean difference and 95% limits of agreement (LoA). RESULTS: The volume as measured by three-dimensional echocardiography and cMR was comparable with the slightly higher end-diastolic volumes measured by cMR (mean difference 15.24 ml; LoA -53.6 to 26.5 ml, end-systolic volume 0.3 ml; LoA -19.9 to 20.5 ml). Long shortening was very similar in the two methods (1.5%; LoA -3.9 to 7%), whereas Circ strain was systematically lower with cMR (-8.5%; LoA -15.5 to -1.5%). Very similar values between three-dimensional echo and cMR both for Slope of strain-volume curves (-0.015; LoA -0.08 to 0.05) and ratio (-0.001; LoA -0.04 to 0.04) were observed in the longitudinal plane. Analysis of strain-volume per patient showed a significant correlation coefficient between techniques for both Long Slope (r = 0.65; P = 0.001) and Long Ratio (r = 0.70; P = 0.001). CONCLUSION: Longitudinal strain-volume analysis performed with three-dimensional speckle-tracking echocardiography is closely comparable with cMR, which is usually considered the gold standard for volume and function assessment.

[Prevalence of cardiac and extracardiac incidental findings in the evaluation of coronary artery disease by multidetector computed tomography]. / Prevalenza di reperti occasionali cardiaci ed extracardiaci nella valutazione delle coronarie con tomografia computerizzata multidetettore.

BACKGROUND: With the widespread use of multidetector computed tomography (MDCT) coronary angiography, cardiac and extracardiac incidental findings in cardiac imaging might be detected. The aim of this study was to determine the prevalence of cardiac and extracardiac incidental findings in a population of consecutive patients undergoing coronary MDCT. METHODS: A total of 840 consecutive patients with known or suspected heart disease underwent cardiac MDCT. All patients were assessed with 64-slice MDCT; the examination was performed by limiting the anatomical region examined between the bifurcation of the trachea and the cardiac apex with the aim of obtaining excellent image quality and low cardiac radiological exposure. RESULTS: Overall, 81 incidental findings in 72 patients (9%) were identified, of which 18 were cardiac (2%) and 63 extracardiac (7%). Extracardiac incidental findings were mainly represented by pulmonary nodules (19%). CONCLUSIONS: A significant number of cardiac and extracardiac incidental findings were observed at cardiac MDCT, with the prevalence depending on technical aspects of image acquisition and patient characteristics. Incidental findings should be carefully searched for and reported because they may have an impact on clinical follow-up indications that is not without cost and risk.

[Nutrition and malnutrition in the intensive coronary care unit. Fundamentals for the clinical cardiologist]. / Nutrizione e malnutrizione in terapia intensiva cardiologica. Nozioni di base per il cardiologo clinico.

Patients admitted to coronary care units (CCU) have largely changed in the last decades. As observed in national and international registries, they are older, with different degrees of disability and several comorbidities. Moreover, they often undergo complex procedures. In this scenario, the cardiologist of the CCU has to deal with multidisciplinarity that should involve physiology and pathophysiology of nutrition. Despite the lack of specific data about our CCUs, hospital malnutrition is indeed a common entity that can reach a prevalence of 50% in elderly patients aged more than 75 years old. Malnutrition has several consequences in CCU patients since it involves respiratory drive, immune system and, clinically, patients have longer CCU stay and more complications. Briefly, malnutrition has a significant impact on their final outcome. In the clinical arena, the main issues for CCU physicians are the nutritional screening tools to promote an early recognition of patients with malnutrition, the pathophysiological knowledge of nutrition for a correct interaction with nutritionists, and the way of administration with its major complications. The changes in the population within CCUs are relatively recent and, although specific data in the cardiology setting are still scarce, nutrition science has reached a high level of knowledge to understand and plan tailored nutritional schemes based on the clinical and demographic features of our sick patients.

Left ventricular rotational dyssynchrony before cardiac resynchronization therapy: a step forward into ventricular mechanics.

AIMS: Heart failure patients show impaired left ventricular rotation and twist. In patients undergoing cardiac resynchronization therapy (CRT) significance of preimplant left ventricular rotational timing between different ventricular regions is unknown. We thoroughly evaluated, in patients eligible for CRT, baseline left ventricular rotational mechanics, also assessing segmental rotational timing, and investigated whether the presence of rotational dyssynchrony may be associated with echocardiographic response. METHODS: By two-dimensional speckle-tracking echocardiography, baseline peak apical and basal rotation, peak twist, and time-related parameters, such as delays between opposite segments at base and apex, were assessed in 55 CRT patients and 11 healthy participants. RESULTS: At 6 months, 30 (54%) patients were echocardiographic responders. Left ventricular rotation and twist had no association with response. All time-related parameters were significantly altered in CRT patients. Maximum basal and apical segments delay, and anteroseptal-posterior delays at base and apex, were longer in responders than in nonresponders (P < 0.05 for all), regardless of the presence of left bundle branch block (LBBB) and QRS duration. At multivariable analysis, apical anteroseptal-posterior delay resulted as independently associated with response [odds ratio (OR): 1.022 (1.007-1.038); P = 0.004]. A cut-off value of 97.5 ms for apical anteroseptal-posterior delay predicted response with 96% specificity and 57% sensitivity (AUC = 0.83). Magnitude of left ventricular reverse remodeling was significantly related to apical anteroseptal-posterior delay (P = 0.001). CONCLUSION: In heart failure patients eligible for CRT, left ventricular rotational timing is altered. Dyssynchrony in rotational mechanics shows a specific pattern in responders regardless of the presence of LBBB. Apical anteroseptal-posterior rotational delay is independently associated with left ventricular reverse remodeling.

Myocardial T1 and T2 mapping in diastolic and systolic phase.

The aim of this study was to evaluate the regional (i.e. myocardial segments) variability as well as the overall image quality of cardiac T1 and T2 maps obtained in diastole and in systole. In 22 healthy subjects (group-1), diastolic T1 and T2 maps were obtained at 1.5 T in short-axis view at basal, mid-ventricular and apical level, as well as in 4-chamber (4 ch) and in 2-chamber (2 ch) views. In another group of 25 patients (group-2), the maps were obtained in both diastole and systole. In the group-1, 15.4% of myocardial segments in T1 maps and 0.8% of myocardial segments in T2 maps, mainly located at apical level, showed relevant artifacts and/or partial-volume effect and had to be discarded. We found no significant difference in T1 values among basal, mid-ventricular and apical segments. T2 values at apical level were significantly higher than at basal and mid-ventricular level (short-axis, p < 0.0001; 4 ch, p < 0.009; 2 ch, p = 0.0002 at ANOVA tests). In the group-2, 21.1%/5.3% and 4.0%/0.8% of segments showed relevant artifacts in diastolic/systolic T1 and T2 maps, respectively. Apical T2 values were significantly lower in systole than in diastole. In systole, there were no significant differences in T1/T2 among basal, mid-ventricular and apical segments. The overall quality of T1 and T2 maps drops in apical segments. This could be problematic when evaluating focal myocardial changes. The acquisition in systole increases the number of evaluable segments.

The cold facts of long-term ECG monitoring.

Two recently published trials have provided evidence in favor of longer ECG monitoring among patients with cryptogenic stroke (CS). In the CRYSTAL-AF trial, new atrial fibrillation (AF) was detected in 12.4% of patients with implantable monitor when compared with 2% among those receiving standard follow-up. A similar result was observed in the EMBRACE trial in which AF was detected in 16.1% of patients who received 30-day event recorder (3.2% in controls). These data are compelling in convincing us that long-term ECG technologies have superior sensitivity for the detection of AF in CS; however, clinical specificity for the definition of CS etiology of such findings cannot be established and can be lower than expected, leaving open questions about the etiologic weight of AF in CS. The causative role of AF in this subpopulation remains to be proven, and diagnostic routes cannot be solely unbalanced toward the research of AF.