Delayed 68Ga-FAPI-46 PET/MR imaging confirms ongoing fibroblast activation in patients after acute myocardial infarction.

Purpose of the Report: Combined cardiac 68Ga-Fibroblast-Activation Protein-alpha inhibitor (FAPI) positron-emission tomography (PET) and cardiac magnetic resonance imaging (MRI) constitute a novel diagnostic tool in patients for the assessment of myocardial damage after an acute myocardial infarction (AMI). Purpose of this pilot study was to evaluate simultaneous Ga-68-FAPI-46-PET/MR imaging in the delayed phase after AMI. Material and Methods: Eleven patients underwent hybrid 68Ga-FAPI-46 PET/MRI post AMI. Standardized uptake values and fibroblast activation volume (FAV) were calculated and correlated with serum biomarkers and MRI parameters. Results: Significant 68Ga-FAPI-46 uptake could be demonstrated in 11 (100 %) patients after a mean period of 30.9 ± 22.0 days. FAV significantly exceeded the infarction size in MRI and showed a good correlation to MRI parameters as well as to serum biomarkers of myocardial damage. Conclusions: 68Ga-FAPI-46 PET/MRI offers molecular and morphological imaging of affected myocardium after AMI. This study demonstrates ongoing fibroblast activation in a delayed phase after AMI and generates hypotheses for future studies while aiming for a better understanding of myocardial remodeling following ischemic tissue damage.

Pulsed field ablation and cryoballoon ablation for pulmonary vein isolation: insights on efficacy, safety and cardiac function.

BACKGROUND: Pulmonary vein isolation (PVI) has become the cornerstone treatment of atrial fibrillation (AF). While in cryoablation cell damage is caused by thermal effects, lately, pulsed field ablation (PFA) has been established as a novel non-thermal tissue-specific ablation modality for PVI. However, data comparing outcomes of patients undergoing either PFA or cryoballoon ablation (CBA) for primary PVI are sparse. METHODS: Consecutive patients with AF undergoing PVI by either CBA or PFA were included in the analysis. The primary outcome was the time to AF/AT recurrence. For secondary outcomes, clinical and periprocedural parameters were compared. RESULTS: In total, outcomes of 141 AF patients treated by PFA (94 patients) or CBA (47 patients) were compared. After 365 days, 70% of patients in the PFA group and 61% of patients in the CBA group were free from AF/AT (HR 1.35, 95% CI 0.60-3.00; p = 0.470). No deaths occurred. While symptoms alleviated in both groups, only after PFA, we observed significant improvement of left atrial volume index (PFA group baseline: 40 [31;62] ml/m2, PFA group follow-up: 35 [29;49] ml/m2; p = 0.015), NT-pro BNP levels (PFA group baseline: 1106 ± 2479 pg/ml, PFA group follow-up: 1033 ± 1742 pg/ml; p = 0.048), and left ventricular ejection fraction (LVEF) (PFA group baseline: 55 [48;60] %, PFA group follow-up: 58 [54;63] %; p = 0.006). PVI by PFA was the only independent predictor of LVEF improvement. CONCLUSION: In our study, we show that CBA and PFA for PVI are of similar efficacy when it comes to AF recurrence. However, our findings suggest that PFA rather than CBA might induce left atrial reverse remodeling thereby contributing to left ventricular systolic function.

Post-traumatic stress disorder among COVID-19-affected high-risk cardiac patients.

BACKGROUND: During the first coronavirus disease 2019 (COVID-19) wave there was a high prevalence of mental health impairments and post-traumatic stress disorder (PTSD), particularly in patients with comorbid cardiac diseases. METHODS: During waves 2-5, all hospitalized patients with cardiac problems and suspected COVID-19 were eligible to participate in this study. RESULTS: The prevalence of PTSD was 31.4% (n=48) in 153 participants. No age- and gender-related differences for PTSD were found. CONCLUSIONS: The prevalence is lower than during the first wave but higher than in patients reported in other studies who were isolated at home. Routine mental health assessments are strongly recommended for patients at risk.

Association between different dimensions of anger and symptoms of post-traumatic stress disorder in at-risk cardiovascular patients during the COVID-19 pandemic.

Introduction: The common connecting factor between PTSD and cardiovascular diseases lies in the disruption of the stress processing system. The COVID-19 pandemic has led to an increase in stress levels worldwide. Due to the life-threatening situation of affected risk patients, this also led to the accumulation of post-traumatic stress symptoms (PTSS). The influence of anger on cardiovascular diseases has hardly been investigated so far. The focus of this study is on anger regulation in cardiovascular risk patients. The COVID-19 pandemic is considered as an additional stressor in this study, but not as a separate entity. The hypothesis is that individuals with inward anger are more prone to post-traumatic stress disorder (PTSD). Methods: As part of the routine examination, all patients who were hospitalized between January 1st, 2021 and May 31st, 2022 with high-risk cardiovascular diseases were included. A total of N = 153 (84.1%) subjects participated in the study. On admission, anger (STAXI-2) and PTSD (PCL-5) were assessed using questionnaires. The relationship between different domains of anger and PTSS was examined. Results: Inwardly directed anger was more pronounced in this population than in a standard sample (+1 SD) and had a significant impact on the presence of PTSD (B = -0.72, p < 0.001). Additionally, correlations were found between inward-directed anger and PTSD, as well as all other anger expressions studied and the PTSD total score. Discussion: It can be assumed that anger and its regulation are relevant factors for both cardiac diseases and PTSD. The study results can be used for prevention, rehabilitation and therapeutic measures. However, the impact of inner anger on PTSD is theoretical and based on statistical testing. A confirmatory longitudinal study is needed to substantiate these results.

Visualization of fibroblast activation using 68Ga-FAPI PET/CT after pulmonary vein isolation with pulsed field compared with cryoballoon ablation.

BACKGROUND: Pulsed-field ablation (PFA) is a novel ablation modality for atrial fibrillation (AF) ablating myocardium by electroporation without tissue-heating. With its different mechanism of tissue ablation, it is assumed that lesion creation is divergent to thermal energy sources. 68Ga-fibroblast-activation protein inhibitor (FAPI) PET/CT targets FAP-alpha expressed by activated fibroblasts. We aimed to assess 68Ga-FAPI uptake in pulmonary veins as surrogate for ablation damage after PFA and cryoballoon ablation (CBA). METHODS: 26 patients (15 PFA, 11 CBA) underwent 68Ga-FAPI-PET/CT after ablation. Standardized uptake values (SUV) and fibroblast-activation volumes of localized tracer uptake were assessed. RESULTS: Patient characteristics were comparable between groups. In PFA, focal FAPI uptake was only observed in 3/15 (20%) patients, whereas in the CBA cohort, 10/11 (90.9%) patients showed atrial visual uptake. We observed lower values of SUVmax (2.85 ± 0.56 vs 4.71 ± 2.06, P = 0.025) and FAV (1.13 ± 0.84 cm3 vs 3.91 ± 2.74 cm3, P = 0.014) along with a trend towards lower SUVpeak and SUVmean in PFA vs CBA patients, respectively. CONCLUSION: Tissue response with respect to fibroblast activation seems to be less pronounced in PFA compared to established thermal ablation systems. This functional assessment might contribute to a better understanding of lesion formation in thermal and PFA ablation potentially contributing to better safety outcomes.

Characterization of temporal electrical activity patterns for detection of critical isthmus regions of recurrent atypical atrial flutter.

INTRODUCTION: Identifying the critical isthmus region (CIR) of atrial re-entry tachycardias (AT) is challenging. The Lumipoint® (LP) software, developed for the Rhythmia® mapping system, aims to facilitate the successful ablation of ATs by identifying the CIR. OBJECTIVE: The objective of this study was to evaluate the quality of LP regarding the percentage of arrhythmia-relevant CIR in patients with atypical atrial flutter (AAF). METHODS: In this retrospective study, we analyzed 57 AAF forms. Electrical activity (EA) was mapped over tachycardia cycle length resulting in a two-dimensional EA pattern. The hypothesis was that EA minima suggest potential CIRs with slow-conduction-zone. RESULTS: A total of n = 33 patients were included, with the majority of patients being already preablated (69.7%). LP algorithm identified a mean of 2.4 EA minima and 4.4 suggested CIRs per AAF form. Overall, we observed a low probability of identifying only the relevant CIR (POR) at 12.3% but a high probability that at least one CIR is detected (PALO) at 98.2%. Detailed analysis revealed EA minima depth (≤20%) and width (>50 ms) as the best predictors of relevant CIRs. Wide minima occurred rarely (17.5%), while low minima were more frequently present (75.4%). Minima depth of EA ≤ 20% showed the best PALO/POR overall (95% and 60%, respectively). Analysis in recurrent AAF ablations (five patients) revealed that CIR in de novo AAF was already detected by LP during the index procedure. CONCLUSION: The LP algorithm provides an excellent PALO (98.2%), but poor POR (12.3%) to detect the CIR in AAF. POR improved by preselection of the lowest and widest EA minima. In addition, there might be the role of initial bystander CIRs becoming relevant for future AAFs.

Clinical features and predictors of atrial fibrillation in patients with light-chain or transthyretin cardiac amyloidosis.

AIMS: The study aimed to investigate the prevalence, phenotypic characteristics, and predictors of atrial fibrillation (AF) in patients presenting with cardiac amyloidosis (CA) of light-chain (AL) or transthyretin (ATTR) type. METHODS AND RESULTS: Clinical, biochemical, and echocardiographic data of patients presenting with CA between 2005 and 2020 were retrospectively collected. CA staging was based on established biomarker systems. Binomial logistic regression was run to analyse the effects of clinical variables on the likelihood of AF. The study included 133 patients [53% AL, 41% wild-type (wt) ATTR-CA, & 6% hereditary ATTR-CA]. Mean age was 71 years, and 80% were male patients. AF was diagnosed in 64 (48%) patients (28% in AL-CA, 80% in wtATTR, 13% in hATTR, P < 0.001). Patients with AF were older (74 vs. 69 years, P < 0.001), more likely to have wtATTR-CA (67 vs. 16%, P < 0.001), exhibited more often New York Heart Association ≥ III symptoms (66 vs. 45%, P = 0.02) and carried a higher burden of comorbidities. AF patients had lower left ventricular ejection fraction (47 vs. 53%, P < 0.005), higher left atrial volume index (54 vs. 46 mL/m2 , P = 0.007), higher pulmonary artery pressure (42 vs. 31 mmHg, P = 0.008), and worse tricuspid annular plane systolic excursion values (17 vs. 20 mm, P = 0.01). Mitral regurgitation ≥ Grade 2 was more frequent in AF (56 vs. 25%, P < 0.001). Higher ATTR-CA stage was associated with higher AF prevalence (47% vs. 74% vs. 94%, P < 0.001, for Stages I, II, & III, respectively). Higher AL-CA stage was associated with lower AF prevalence (0% vs. 40% vs. 31% vs. 18%, P < 0.001, for Stages I, II, IIIa, & IIIb, respectively). Three independent predictors for AF were identified in a multivariate logistic regression model with 81.5% classification accuracy: AL type [odds ratio (OR) 0.1, confidence interval (CI) 0.01-0.29, P = 0.001], estimated glomerular filtration rate (OR 0.9, CI 0.93-0.99, P = 0.03), and body mass index (OR 1.3, CI 1.07-1.66, P = 0.01). ATTR amyloidosis was associated with a 10-fold higher risk of AF. During 1 year follow-up, only one episode of ischaemic stroke was reported. CONCLUSIONS: Atrial fibrillation affects nearly half of all patients with CA. Patients presenting with AF have more severe symptoms and higher burden of comorbidities. ATTR type of amyloidosis is the strongest predictor of AF. Prospective screening for occult AF may be considered in ATTR-CA.

Visualization of thermal damage using 68 Ga-FAPI-PET/CT after pulmonary vein isolation.

PURPOSE: 68 Ga-fibroblast-activation protein inhibitor (FAPI) positron emission tomography (PET) is a novel technique targeting FAP-alpha. This protein is expressed by activated fibroblasts which are the main contributors to tissue remodeling. The aim of this proof-of-concept study was to assess 68 Ga-FAPI uptake in the pulmonary vein (PV) region of the left atrium after pulmonary vein isolation (PVI) with cryoballoon ablation (CBA) and radiofrequency (RFA) as a surrogate for thermal damage. METHODS: Twelve PVI patients (5 RFA, 7 CBA) underwent 68 Ga-FAPI-PET 20.5 ± 12.8 days after PVI. Five patients without atrial fibrillation or previous ablation served as controls. Standardized uptake values of localized tracer uptake were calculated. RESULTS: Focal FAPI uptake around the PVs was observed in 10/12 (83.3%) PVI patients, no uptake was observed in 2 PVI patients and all controls. Patients after PVI had higher FAPI uptake in PVs compared to controls (SUVmax: 4.3 ± 2.2 vs. 1.6 ± 0.2, p < 0.01; SUVpeak: 2.9 ± 1.4 vs. 1.3 ± 0.2, p < 0.01). All CBA patients had an intense uptake, while in the RFA, group 2 (40%), 1 (20%), and 2 (40%) patients had an intense, moderate, and no uptake, respectively. We observed higher uptake values (SUVpeak) in CBA compared to RFA patients (4.4 ± 1.5 vs. 2.5 ± 0.8, p = 0.02). CONCLUSION: We demonstrate in-vivo visualization of 68 Ga-FAPI uptake as a surrogate for fibroblast activation after PVI. CBA seems to cause more pronounced fibroblast activation following tissue injury than RFA. Future studies are warranted to assess if this modality can contribute to a better understanding of the mechanisms of AF recurrence after PVI by lesion creation and gap assessment.

Proximity to COVID-19 on Mental Health Symptoms among Hospital Medical Staff.

BACKGROUND: Exposure to patients with COVID-19 can have a significant impact on mental health of hospital medical staff. The aim of this study was to examine the influence of proximity to patients with COVID-19 considering occupational position and gender on the mental health of hospital staff. SUBJECTS AND METHODS: N=78 participants were included in the study, with n=40 of them with direct contact to patients with COVID-19 (51%); eight had contact with patients suspected of having COVID-19 (10%), and n=30 with no direct contact to people with COVID-19 (39%). RESULTS: Multinomial regression analyses showed that proximity had a negative (inverse) influence on avoidance behaviour as part of PTSD, physical symptoms, somatization, compulsiveness and anger expression-in as tendency to suppress anger. In addition, there was a significant impact of the female gender on increased physical symptoms, while age, work experience and occupation had no further influence. CONCLUSIONS: These results that hospital medical staff is less psychologically stressed when closer to COVID-19 patients are inconsistent with previous studies. Self-efficacy and locus of control in these situations are relevant for processing the trauma. In summary, perception of personal risk is essential. Proximity is believed to be a proxy variable for personal risk perception. As a synopsis of these results, regular briefings of the hospital staff are recommended to prevent psychological impairment. They should contain specific information about conditions in the affected wards and the risk of infection, which could help reduce risk perception of medical personnel.

Central retinal artery occlusion as a first sign of atrial fibrillation: A 3-year retrospective single-center analysis.

BACKGROUND: Central retinal artery occlusion ((C)RAO) is known to be associated with stroke and/or atrial fibrillation (AF). Nevertheless, patients often present at the ophthalmologist initially and it is unknown how many of these receive an adequate cardiological/neurological work-up (CWU/NWU), including a 24 h-Holter-ECG. HYPOTHESIS: Hypothesis of this study was that patients with (C)RAO do not undergo CWU on regular basis and that new-onset AF is more often detected in patients with CWU. METHODS AND RESULTS: We performed a retrospective analysis of n = 292 consecutive patients who presented at an ophthalmology department with the diagnosis of (C)RAO during a 3-year period. After excluding patients with known AF, meeting exclusion criteria, inability to comply with the protocol, missed land phoneline, or death during follow-up a total of 174 patients were enrolled; mean follow-up was 20 ± 12 months. The CHA2 DS2 -VASc score of the cohort was 5.3 ± 1.4. Our analysis revealed that only 50.6% of patients received a CWU including a single Holter-ECG after the index-event. In 12.6% cases new-onset AF was diagnosed, while the rate was higher in patients with CWU compared to patients without CWU (18.2 vs. 7.0%; p = 0.26). Evaluation of oral anticoagulation (OAC) therapy showed that only 66% of patients with AF were treated according to guidelines. CONCLUSION: Only half of patients with (C)RAO underwent CWU. Despite minimal monitoring, rate of new diagnosed AF was high. Our results confirm that (C)RAO identifies a high-risk population for AF. These results illustrate the importance to implement standardized CWU in (C)RAO patients presenting at the ophthalmologist.

Visualization of Fibroblast Activation After Myocardial Infarction Using 68Ga-FAPI PET.

AIMS: The aim of this retrospective analysis was to examine the pattern of cardiac 68Ga-fibroblast-activation protein-α inhibitor (FAPI) uptake in patients after acute myocardial infarction (AMI) using PET and to investigate its association with results of coronary angiography. We correlated FAPI uptake with biomarkers of myocardial damage including left ventricular function. METHODS AND RESULTS: A cohort of 10 patients with no history of coronary artery disease underwent PET 18 ± 20.6 days after AMI (ST-segment elevation myocardial infarction [n = 5] and non-ST-segment elevation infarction [n = 5]), respectively. SUVmax, SUVmean, and SUVpeak of localized tracer uptake were calculated; tracer uptake volume was reported as fibroblast activation volume (FAV), with imaging data being correlated with clinical parameters. Focal FAPI uptake was observed in all patients. Average uptake at 10 minutes postinjection was 8.9 ± 4.4 (SUVmax), 7.6 ± 4.0 (SUVpeak), and 5.3 ± 2.8 (SUVmean), respectively. Affected myocardium showed a partial to complete match between tracer uptake and confirmed culprit lesion by coronary angiography in 44.4% and 55.6% of patients, respectively. A strong correlation between FAV and peak creatine kinase level (r = 0.90, P < 0.01) and inverse correlation of FAV with left ventricular function (r = -0.69, P < 0.05) was observed. CONCLUSIONS: This analysis demonstrates in vivo visualization of fibroblast activation after AMI. The uptake area showed a very good agreement with the affected coronary territory. A strong correlation of the de novo established parameter FAV with left ventricular function and peak creatine kinase was observed. This imaging modality may provide important insights into mechanisms of structural remodeling after AMI at an early stage.

Saturation recovery-prepared magnetic resonance angiography for assessment of left atrial and esophageal anatomy.

OBJECTIVES: Magnetic resonance angiography (MRA) has been established as an important imaging method in cardiac ablation procedures. In pulmonary vein (PV) isolation procedures, MRA has the potential to minimize the risk of severe complications, such as atrio-esophageal fistula, by providing detailed information on esophageal position relatively to cardiac structures. However, traditional non-gated, first-pass (FP) MRA approaches have several limitations, such as long breath-holds, non-uniform signal intensity throughout the left atrium (LA), and poor esophageal visualization. The aim of this observational study was to validate a respiratory-navigated, ECG-gated (EC), saturation recovery-prepared MRA technique for simultaneous imaging of LA, LA appendage, PVs, esophagus, and adjacent anatomical structures. METHODS: Before PVI, 106 consecutive patients with a history of AF underwent either conventional FP-MRA (n = 53 patients) or our new EC-MRA (n = 53 patients). Five quality scores (QS) of LA and esophagus visibility were assessed by two experienced readers. The non-parametric Mann-Whitney U-test was used to compare QS between FP-MRA and EC-MRA groups, and linear regression was applied to assess clinical contributors to image quality. RESULTS: EC-MRA demonstrated significantly better image quality than FP-MRA in every quality category. Esophageal visibility using the new MRA technique was markedly better than with the conventional FP-MRA technique (median 3.5 [IQR 1] vs median 1.0, p < 0.001). In contrast to FP-MRA, overall image quality of EC-MRA was not influenced by heart rate. CONCLUSION: Our ECG-gated, respiratory-navigated, saturation recovery-prepared MRA technique provides significantly better image quality and esophageal visibility than the established non-gated, breath-holding FP-MRA. Image quality of EC-MRA technique has the additional advantage of being unaffected by heart rate. ADVANCES IN KNOWLEDGE: Detailed information of cardiac anatomy has the potential to minimize the risk of severe complications and improve success rates in invasive electrophysiological studies. Our novel ECG-gated, respiratory-navigated, saturation recovery-prepared MRA technique provides significantly better image quality of LA and esophageal structures than the traditional first-pass algorithm. This new MRA technique is robust to arrhythmia (tachycardic, irregular heart rates) frequently observed in AF patients.

Gender Differences in Anger Among Hospital Medical Staff Exposed to Patients with COVID-19.

Purpose: Occupational exposure to patients with COVID-19 is a stress factor. The aim of this study was to assess gender differences in anger among medical hospital staff. Methods: N=78 hospital employees with direct or indirect contact to patients with COVID-19 completed State-Trait Inventory-2. Results: Female personnel showed higher scores in the main "trait anger" scale and its subscale "anger temperament," whereas "anger control-out" was significant lower. Direct patient contact had no influence. Conclusion: More specific training for female hospital staff could achieve health-related equity. Focusing on anger as a leading indicator could lead to better prevention and self-monitoring. Registered at Clinicaltrials.gov (NCT04368312).

The INFluence of Remote monitoring on Anxiety/depRession, quality of lifE, and Device acceptance in ICD patients: a prospective, randomized, controlled, single-center trial.

BACKGROUND: Impact of telemedicine with remote patient monitoring (RPM) in implantable cardioverter-defibrillator (ICD) patients on clinical outcomes has been investigated in various clinical settings with divergent results. However, role of RPM on patient-reported-outcomes (PRO) is unclear. The INFRARED-ICD trial aimed to investigate the effect of RPM in addition to standard-of-care on PRO in a mixed ICD patient cohort. METHODS AND RESULTS: Patients were randomized to RPM (n = 92) or standard in-office-FU (n = 88) serving as control group (CTL). At baseline and on a monthly basis over 1 year, study participants completed the EQ-5D questionnaire for the primary outcome Quality of Life (QoL), the Hospital Anxiety and Depression Scale, and the Florida Patient Acceptance Survey questionnaire for secondary outcomes. Demographic characteristics (82% men, mean age 62.3 years) and PRO at baseline were not different between RPM and CTL. Primary outcome analysis showed that additional RPM was not superior to CTL with respect to QoL over 12 months [+ 1.2 vs. + 3.9 points in CTL and RPM group, respectively (p = 0.24)]. Pre-specified analyses could not identify subgroups with improved QoL by the use of RPM. Neither levels of anxiety (- 0.4 vs. - 0.3, p = 0.88), depression (+ 0.3 vs. ± 0.0, p = 0.38), nor device acceptance (+ 1.1 vs. + 1.6, p = 0.20) were influenced by additional use of RPM. CONCLUSION: The results of the present study show that PRO were not improved by RPM in addition to standard-of-care FU. Careful evaluation and planning of future trials in selected ICD patients are warranted before implementing RPM in routine practice.

Impact of diabetes as a risk factor in patients undergoing subcutaneous implantable cardioverter defibrillator implantation: A single-centre study.

INTRODUCTION: Patients with diabetes mellitus are known to carry an increased risk for surgical site infections and perioperative complications. The subcutaneous implantable cardioverter defibrillator is an established treatment option in patients at risk for sudden cardiac death especially with an increased risk for infection over time. METHODS AND RESULTS: Forty-eight patients (mean age = 55.0 ± 21.3 years, 31.3% patients with diabetes mellitus, 75% male) who underwent consecutive subcutaneous implantable cardioverter defibrillator surgery between February 2016 and May 2019 were retrospectively analysed. Overall adverse events including relevant bleeding complications, any surgical wound problems and infections requiring reoperation or device malfunction were evaluated as primary combined safety endpoint. Patients with diabetes mellitus tended to be older with a higher body mass index compared to non-diabetes mellitus. Procedure duration and postsurgery hospital days were not different in diabetes mellitus versus non-diabetes mellitus patients. Analysis of the primary combined endpoint showed no significant difference but a trend towards higher event rates in the diabetes mellitus group (diabetes mellitus vs non-diabetes mellitus: 20% vs 12.1%, p = 0.119). CONCLUSION: Diabetes mellitus is a frequent and relevant variable in patients undergoing subcutaneous implantable cardioverter defibrillator implantation represented by 31.3% in this consecutive cohort. Our results suggest that diabetes mellitus is not associated with a prolonged hospital stay or increased rate of periprocedural adverse events.

Impact of previous left atrial ablation procedures on the mechanism of left atrial flutter: A single-centre experience.

INTRODUCTION: Left atrial flutter predominantly occurs after surgical or ablation procedures but this entity has also been recently reported in individuals without previous interventions. The use of high-density electroanatomical mapping-systems (HDM) has improved the understanding of underlying mechanisms beyond entrainment maneuvers and substrate analyses. We aimed to evaluate the mechanism of left atrial (LA) flutters in preablated vs ablation-naïve individuals and sought to assess the efficacy of empiric ablations sets in these groups. METHODS AND RESULTS: We included 55 patients admitted for ablation of LA flutter between July 2017 and August 2019. On the basis of HDM analyses the arrhythmia mechanism was determined with consecutive ablation targeting the suspected critical isthmus. Mean age was 69.8 ± 10.7 years, with 26 of 55 (47.3%) male patients. Thirty-nine (71%) patients had previously undergone LA ablation. Arrhythmia mechanisms differed between preablated and ablation-naïve patients as anatomical structure-related LA flutters (perimitral, roof-dependent, within-pulmonary veins) were more frequent in the preablated cohort compared to ablation-naïve individuals (74.4% vs 43.8%; P = .03). In ablation-naïve patients, most flutters (9 of 16, 56.3%) were related to low-voltage areas at the anterior/posterior wall. Acute termination rates were high (>90%) in both groups. Empirical mitral isthmus or roof lines showed a potential higher success rate in preablated patients. CONCLUSION: We identified different mechanisms of LA flutters in preablated vs ablation-naïve patients. In ablation-naïve patients, most tachycardias involved low-voltage areas rather than anatomical structures. Using HDM, acute success rates were high. Hypothetical linear ablations were less successful in ablation-naïve individuals, further highlighting the need to identify the specific individual tachycardia mechanism in these patients.

Cardiac PET/MRI: Current Clinical Status and Future Perspectives.

Combined PET/MRI has now been in clinical routine for almost 10 years. Since then, it has not only had to face validation, comparison and research questions, it has also been increasingly used in clinical routine. A number of cardiovascular applications have become established here, whereby viability imaging and assessment of inflammatory and infiltrative processes in the heart are to be emphasized. However, further interesting applications are expected in the near future. This review summarizes the most important clinical applications on the one hand and mentions interesting areas of application in research on the other.

Left-ventricular innervation assessed by 123I-SPECT/CT is associated with cardiac events in inherited arrhythmia syndromes.

AIMS: Impaired myocardial sympathetic innervation assessed by 123Iodine-Metaiodobenzylguanidine (123I-MIBG) scintigraphy is associated with cardiac events. Since regional disparities of structural abnormalities are common in inherited arrhythmia syndromes (iAS), a chamber-specific innervation assessment of the right (RV) and left ventricle (LV) could provide important insights for a patient-individual therapy. Aim of this study was to evaluate chamber-specific patterns of autonomic innervation by Single-photon emission computed tomography/computed tomography (SPECT/CT) in patients with iAS with respect to clinical outcome regarding cardiac events. METHODS AND RESULTS: We assessed ventricular sympathetic innervation (LV, RV and planar heart/mediastinum-ratios, and washout-rates) by 123I-MIBG-SPECT/CT in 48 patients (arrhythmogenic right ventricular cardiomyopathy [ARVC], n = 26; laminopathy, n = 8; idiopathic ventricular fibrillation [iVF], n = 14) in relation to a composite clinical endpoint (ventricular arrhythmia; cardiac death; cardiac hospitalization). RV tracer uptake was lower in patients with ARVC than in laminopathy and iVF patients (1.7 ± 0.4 vs. 2.1 ± 0.7 and 2.1 ± 0.5, respectively). Over a median follow-up of 2.2 years, the combined endpoint was met in 18 patients (n = 12 ventricular tachyarrhythmias, n = 5 hospitalizations, n = 1 death). LV, but not RV H/M ratio was associated with the combined endpoint (hazard-ratio 2.82 [1.30-6.10], p < 0.01). After adjustment for LV and RV function, LV H/M-ratio still remained a significant predictor for cardiac events (hazard-ratio 2.79 [1.06-7.35], p = 0.04). CONCLUSION: We demonstrated that chamber-specific 123MIBG-SPECT/CT imaging is feasible and that reduced LV sympathetic innervation was associated with worse outcome in iAS. These findings provide novel insights into the potential role of regional autonomic nervous system heterogeneity for the evolution of life-threatening cardiac events in iAS.

Assessment of right ventricular sympathetic dysfunction in patients with arrhythmogenic right ventricular cardiomyopathy: An 123I-metaiodobenzylguanidine SPECT/CT study.

PURPOSE: The purpose of the study was to evaluate a novel approach for the quantification of right ventricular sympathetic dysfunction in patients diagnosed with ARVC/D through state-of-the-art functional SPECT/CT hybrid imaging. METHODS: Sympathetic innervation of the heart was assessed using 123I-MIBG-SPECT/CT in 17 patients diagnosed with ARVC according to the modified task force criteria, and in 10 patients diagnosed with idiopathic ventricular fibrillation (IVF). The 123I-MIBG-uptake in the left (LV) and right ventricle (RV) was evaluated separately based on anatomic information derived from the CT scan, and compared to the uptake in the mediastinum (M). RESULTS: There was a significant difference in the LV/M ratio between the ARVC/D and the IVF groups (3.2 ± 0.5 vs. 3.9 ± 0.8, P = 0.014), with a cut-off value of 3.41 (77% sensitivity, 80% specificity, AUC 0.78). There was a highly significant difference in the mean RV/M ratios between both groups (1.6 ± 0.3 vs. 2.0 ± 0.2, P = 0.001), with optimal cut-off for discrimination at 1.86 (88% sensitivity, 90% specificity, AUC 0.93). CONCLUSION: Employing state-of-the-art functional SPECT/CT hybrid imaging, we could reliably assess and quantify right and left ventricular sympathetic innervation. The RV/M ratio was significantly lower in patients diagnosed with ARVC/D and provided sensitive and specific discrimination between patients with ARVC/D and IVF patients.