Combined Use of S-ICD and Absorbable Antibacterial Envelopes: A Proof-of-concept Study.

BACKGROUND: Absorbable antibacterial envelopes (AAEs) are currently recommended in patients undergoing a transvenous ICD implantation in cases at high risk of infection, who are now preferably implanted with a subcutaneous ICD (S-ICD). Nevertheless, experiences using a combined approach with S-ICD and AAE have not been reported. The aim of our study was to evaluate this strategy in patients at very high risk of infection. METHODS: Twenty-five patients were implanted with the S-ICD+AAE using our combined approach, restricted to patients who would fit our decisional flow algorithm identifying very high-risk patients. Patients were followed up 1 month after discharge and every 6 months thereafter. Complications were defined as device-related events requiring medical or surgical intervention for resolution and/or device reprogramming. RESULTS: Twenty-five patients (92% males, mean age 58.5±14.1 years) were implanted with the S-ICD device and the AAE using our combined approach. The most common high-infective risk factors were diabetes requiring insulin treatment (80%) and CKD requiring hemodialysis (48%), with 7 (28%) patients presenting with more than 2 risk factors. A single mild early post-operative hematoma was observed that was managed conservatively with a spontaneous resolution. Despite a very high-risk cohort, only a single late pocket infection was detected and solved conservatively with antibiotic therapy. CONCLUSIONS: The preliminary data of this proof-of-concept study show how a combined deployment of AAE and S-ICD in selected patients at very high risk of infection is a safe and feasible technique and may offer a reliable treatment option in specific and selected clinical settings.

A reproducible sensor pattern to suspect COVID19 pulmonary infection with LATITUDE. Case report and literature review.

A 78 year-old patient with postischaemic dilated cardiomyopathy and severely reduced ejection fraction was implanted with a Boston Scientific RESONATE X4 CRT-D and followed by LATITUDE remote monitoring platform. From the end of January to the end of March 2021 he was hospitalized for COVID19 pneumonia followed by two episodes of acute heart decompensation with bilateral pleural effusion. We remotely followed the patient and identified a typical Heart Logic sensor pattern linked to the COVID19 pneumonia, different from the one linked to the heart failure (HF). We eventually made a literature review on the topic.

Anticoagulation in atrial fibrillation and liver disease: a pooled-analysis of >20 000 patients.

AIMS: Anticoagulation for atrial fibrillation patients with liver disease represents a clinical dilemma. We sought to evaluate the efficacy/safety of different anticoagulation, i.e. vitamin K antagonist (VKA) and non-VKA oral anticoagulants (NOACs) in such patient group. METHODS AND RESULTS: This was a pooled-analysis enrolling up-to-date clinical data. Two subsets: subset A (VKA vs. Non-Anticoagulation) and subset B (NOACs vs. VKA) were pre-specified. The study outcomes were ischaemic stroke (IS)/thromboembolism (TE), major bleeding (MB), intracranial bleeding (ICB), gastrointestinal bleeding (GIB), and all-cause mortality. A total of 20 042 patients' data were analysed (subset A: N = 10 275, subset B: N = 9767). Overall mean age: 71 ± 11 years, mean CHA2DS2-VASc score: 4.0 ± 1.8, mean HAS-BLED score: 3.6 ± 1.2. The majority of the patients had Child-Pugh category (A-B). As compared with Non-Anticoagulation, VKA seemed to reduce the risk of IS/TE [odds ratio (OR): 0.60, P = 0.05], but heighten the risk of all-bleeding events including MB (OR: 2.81, P = 0.01), ICB (OR: 1.60, P = 0.01), and GIB (OR: 3.32, P = 0.01). When compared with VKA, NOACs had similar efficacy in reducing the risk of IS/TE (OR: 0.82, P = 0.64), significantly lower risk of MB (OR: 0.54, P = 0.0003) and ICB (OR: 0.35, P < 0.0001), and trend towards reduced risk of GIB (OR: 0.72, P = 0.12) and all-cause mortality (OR: 0.79, P = 0.35). The favourable effects were maintained in subgroups of individual NOAC. CONCLUSIONS: VKA appears to reduce the risk of IS/TE but increase all-bleeding events. NOACs have similar effect in reducing the risk of IS/TE and have significantly lower risk of MB and ICB as compared with VKA. NOACs seem to be associated with better clinical outcome than VKA in patients with mild-moderate liver disease.

Single-sweep pulmonary vein isolation using the new third-generation laser balloon-Evolution in ablation style using endoscopic ablation system.

BACKGROUND: The endoscopic ablation system (EAS) is an established ablation device for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). The novel X3 EAS is now equipped with a contiguous circumferential ablation mode (RAPID mode). AIM: To determine the feasibility of single-shot fashioned ablation using X3. METHODS: Consecutive patients who underwent AF ablation using X3 were enrolled. We assessed the acute procedural data focusing on "Single-sweep PVI" defined as successful PVI with a single RAPID mode energy application, and on "first-pass isolation" defined as successful PVI after initial circular lesion set. RESULTS: One hundred AF patients (56% male, age: 68 ± 10 years, 66% paroxysmal AF) were analyzed. A total of 379 of 383 PVs (99%) were isolated with X3. Single-sweep PVI and first-pass-isolation were achieved in 214 PVs (56%) and in 362 PVs (95%), respectively. Single-sweep PVI rates varied across PVs with higher rates at the superior PVs (61.2% vs. inferior PVs: 49.5%, p = .0239) and at PVs with maximal ostial diameter <24 mm (57.6% vs. >24 mm: 36.8%, p = .0151). The mean total procedure and fluoroscopy times were 43.0 ± 10 and 4.0 ± 2 min, respectively. In none of the patients an acute thromboembolic event (stroke or transient ischemic attack) or a pericardial effusion/tamponade occurred. A single transient phrenic nerve palsy was observed. CONCLUSION: The new X3 EAS allows for single-shot fashioned ablation in terms of single-sweep PVI in half or more of PVs. The new RAPID ablation mode leads to an improved rate of first-pass isolation associated with very short procedure times without compromising safety.

[Pulmonary embolism and SARS-CoV-2: analysis of patients hospitalized for pulmonary embolism and COVID-19 in a Northern Italian center]. / Embolia polmonare e SARS-CoV-2: analisi delle caratteristiche dei pazienti ricoverati presso un centro nel nord Italia per embolia polmonare associata a COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has shown high morbidity and mortality and the relationship between pulmonary embolism (PE) and COVID-19 is well established in the literature. METHODS: We describe the characteristics of a cohort of COVID-19 patients (EP-COV) hospitalized at our Centre with PE, investigating how COVID-19 may have influenced their outcomes, as compared to patients without COVID-19 hospitalized for PE in the same months of 2020 (EP-2020) and 2019 (EP-2019). RESULTS: EP-COV patients (n=25) were younger (60.5 ± 8.5 vs 71.4 ± 14.5 vs 70.9 ± 11.8 years, p=0.003), more frequently male (76% vs 48% vs 35%, p=0.016), with a lower history of neoplasia (12% vs 47% vs 40%, p=0.028) and more clinically severe (SOFA score 3.4 ± 1.4 vs 2.2 ± 1.4 vs 1 ± 1.1, p<0.001 and PaO2/FiO2 ratio 223.8 ± 75.5 vs 306.5 ± 49.3 vs 311.8 ± 107.5) than EP-2020 (n=17) and EP-2019 patients (n=20). D-dimer and C-reactive protein were higher in EP-COV (p=0.038 e p<0.001, respectively). The rate of concomitant deep vein thrombosis associated with PE did not differ significantly between the three groups. EP-COV patients developed PE more frequently during in-hospital stay than non-COVID-19 patients (p = 0.016). The mortality rate was higher in EP-COV than in EP-2020 and EP-2019 patients (36% vs 0% vs 5%, p=0.019). CONCLUSIONS: In our study, the risk factors for PE in COVID-19 patients seem to differ from the traditional risk factors for venous thromboembolism; EP-COV patients are clinically more severe and display a higher mortality rate than EP-2020 and EP-2019 patients.

Increased procedural safety of cryoballoon pulmonary vein isolation with a double 120 s freeze protocol.

BACKGROUND: Recently a double 120 s freeze cryoballoon (CB) pulmonary vein isolation (PVI) protocol proved to be non inferior to a double 240 s freeze protocol in terms of atrial fibrillation (AF) recurrences. We hypothesized that this approach could also result in an increased procedure safety. METHODS: Eighty consecutive patients treated with a double 120 s freeze protocol (Group CB120) were compared with 80 previous consecutive patients treated with a single 240 s freeze protocol (Group CB240). Procedures were performed with a temperature probe to monitor the luminal esophageal temperature (LET), using a cut off for cryoenergy interruption of 15°C. During ablation at the septal pulmonary veins (PVs), the phrenic nerve (PN) function was monitored by pacing. RESULTS: In CB120 and CB240 the rate of single shot isolation was similar in all PVs. Time to isolation was not different between the two groups. Mean minimal esophageal temperature was lower in LSPV and LIPV of the CB240 group. A total of 4/80 patients (5%) of the CB120 group experienced a PN injury, but no persistent form was recorded; 11/80 patients (14%) of the CB240 group experienced a PN injury, three in a persistent form (p = .10). A LET <15°C was recorded in 3/80 patients (4%) in the CB120 group and in 16/80 patients (20%) in the CB240 group (p < .01). Composite rate of energy-related safety events (LET <15°C and PN injury) was significantly lower in the CB120 (34% vs. 9%, p < .01). CONCLUSIONS: Safety of second generation CB PVI can be increased using a double 120 s freeze protocol.

[Typical atrial flutter catheter ablation complicated by right coronary artery spasm and occlusion. Case report and review of the literature]. / Ablazione di flutter atriale tipico complicata da spasmo ed occlusione della coronaria destra. Caso clinico e revisione della letteratura.

Right coronary artery lesion is an uncommon and serious complication of typical atrial flutter ablation. We report a case of right coronary artery occlusion during atrial flutter ablation managed with percutaneous coronary intervention, combined with a review of the literature, in order to obtain pathogenetic and epidemiological information about this complication.

Ablation Index-guided high-power (50 W) short-duration for left atrial anterior and roofline ablation: Feasibility, procedural data, and lesion analysis (AI High-Power Linear Ablation).

OBJECTIVES: To evaluate the feasibility, procedural data, and lesion characteristics of the anterior line (AL) and roofline (RL) ablation by using ablation index (AI)-guided high power (50 W) among patients with recurrent atrial fibrillation (AF) or atrial tachycardia (AT) after pulmonary vein isolation (PVI). METHODS: Data from 35 consecutive patients with macro-reentrant left atrial tachycardia or substrate at the left atrium anterior wall or roof after previous PVI were collected. Ablation power was set to 50 W, targeting AI 500 for AL and 400 for RL. The first-pass conduction block (FPB) was evaluated. The AL was arbitrarily divided into three (caudal, middle, and cranial) segments to analyze the location of conduction gaps in non-FPB patients. RESULTS: A total of 32 AL and 17 RL were deployed and FPB was achieved in 24 (75%) and 14 (82%) of them, respectively. In the non-FPB group, the most frequent gap location along the AL was the middle third. The final block of AL was achieved in 97%, and the block of RL was achieved in 100%. The radiofrequency (RF) ablation time was short (2.9 ± 0.8 min for AL and 46.2 ± 15.6 s for RL). For AL, the female gender was significantly more frequent in FPB than in non-FPB patients (p = .028); patients with non-FPB were associated with significantly longer RF time as compared to patients with FPB (204 ± 47 s vs. 161 ± 41 s; p = .02). No procedural complications occurred. CONCLUSION: AI-guided high-power (50 W) ablation appears to be a feasible, effective, and fast technique for AL and RL ablation.

Cryoballoon Versus Laserballoon: Insights From the First Prospective Randomized Balloon Trial in Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) represents the cornerstone in atrial fibrillation ablation. Cryoballoon and laserballoon catheters have emerged as promising devices but lack randomized comparisons. Therefore, we sought to compare efficacy and safety comparing both balloons in patients with persistent and paroxysmal atrial fibrillation (AF). METHODS: Symptomatic AF patients (n=200) were prospectively randomized (1:1) to receive either cryoballoon or laserballoon PVI (cryoballoon: n=100: 50 paroxysmal atrial fibrillation + 50 persistent AF versus laserballoon: n=100: 50 paroxysmal atrial fibrillation + 50 persistent AF). All antiarrhythmic drugs were stopped after ablation. Follow-up included 3-day Holter-ECG recordings and office visits at 3, 6, and 12 months. Primary efficacy end point was defined as freedom from atrial tachyarrhythmia between 90 and 365 days after a single ablation. Secondary end points included procedural parameters and periprocedural complications. RESULTS: Patient baseline parameters were not different between both groups. In all (n=200) complete PVI was obtained and the entire follow-up accomplished. Balloon only PVI was obtained in 98% (cryoballoon) versus 95% (laserballoon) requiring focal touch-up in 2 and 5 patients, respectively. Procedure but not fluoroscopy time was significantly shorter in the cryoballoon group (50.9±21.0 versus 96.0±20.4 minutes; P<0.0001 and 7.4±4.4 versus 8.4±3.2 minutes, P=0.083). Overall, the primary end point of no atrial tachyarrhythmia recurrence was met in 79% (cryoballoon: 80.0% versus laserballoon: 78.0%, P=ns). No death, atrio-esophageal fistula, tamponade, or vascular laceration requiring surgery occurred. In the cryoballoon group, 8 transient but no persistent phrenic nerve palsy were noted compared with 2 persistent phrenic nerve palsy and one transient ischemic attack in the laserballoon group. CONCLUSIONS: Both balloon technologies represent highly effective and safe tools for PVI resulting in similar favorable rhythm outcome after 12 months. Use of the cryoballoon is associated with significantly shorter procedure but not fluoroscopy time.

Optimizing cryoballoon pulmonary vein isolation: lessons from >1000 procedures- the Frankfurt approach.

AIMS: Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted ablation strategy for rhythm control in atrial fibrillation (AF). We describe efficacy and safety in a high volume centre with a long experience in the use of the second-generation CB (CB2). METHODS AND RESULTS: Consecutive paroxysmal AF (PAF) or persistent AF (persAF) patients undergoing CB2-PVI were enrolled. Procedural data, efficacy, and safety issues were systematically collected. The 28 mm CB2 was used in combination with an inner lumen spiral catheter, a luminal oesophageal temperature (LET) probe was used with a cut-off of 15°C, the phrenic nerve (PN) monitored during septal PVs ablation. Freeze duration was mainly set at 240 s with a bonus application in case of delayed time-to-isolation (TTI > 75 s). A total of 1017 CB2 procedures were analysed (58% male, 66 ± 12 years old, 70% with PAF). 3964 PVs were identified, 99.8% PVs isolated using solely the 28 mm CB. Mean procedure time was 69 ± 25 min, TTI during the first application was recorded in 77% of PVs after a mean of 48 ± 31 s. We recorded 0.2% cardiac tamponade, 4.8% PN injury (1.6% of PN palsy), and 19% of LET < 15°C. Among 725 patients with follow-up data, 84% with PAF and 75% with persAF were in stable SR at 1 year. Shorter freezing duration and longer TTI were procedural predictors for recurrence. CONCLUSION: Cryoballoon procedures are fast and associated with a benign safety profile. Shorter TTI and longer freeze durations are associated with sinus rhythm during follow-up.

Left atrial appendage (LAA) electrical isolation by Maze-like catheter substrate modification in presence of LAA-occluder device: A case report.

Maze-like linear substrate modification in atrial fibrillation patients nonresponders to pulmonary vein isolation represents a feasible technique to gain left atrial appendage electrical isolation even in the presence of a Watchman occluder device.

Cryoballoon pulmonary vein isolation in treating atrial fibrillation using different freeze protocols: The "ICE-T 4 minutes vs 3 minutes" propensity-matched study (Frankfurt ICE-T 4 vs. 3).

BACKGROUND: Time-to-isolation (TTI) guided second-generation cryoballoon (CB2) ablation has been shown to be effective for pulmonary vein isolation (PVI). OBJECTIVE: The objective of this paper is to compare the safety and clinical outcome of CB2 PVI using the TTI guided 4 minutes vs 3 minutes freeze protocol. METHODS: This was a propensity-matched study based on an institutional database. Symptomatic atrial fibrillation (AF) patients who underwent CB2 PVI and systematic follow-up were consecutively included. RESULTS: A total of 573 patients were identified, of them 214 (107 matched-pairs) symptomatic AF (paroxysmal AF: 61%, persistent AF: 39%) patients (age: 67.7 ± 11.2 years) were analyzed. The baseline characteristics were comparable between the two groups. Procedural time was significantly longer in the 4 minutes group compared to 3 minutes group (67.2 ± 21.8 vs 55.9 ± 16.9 minutes, P < .0001). During a mean follow-up of 2 years, the 4 minutes group was associated with a significantly higher rate of freedom from arrhythmia recurrence compared with the 3 minutes group (66.4% vs 56.1%, P = .009), which was mainly driven by patients with persistent AF. The multivariate regression showed that the 4 minutes freeze was the independent predictor of freedom from arrhythmia recurrence. During the repeat procedure, the 4 minutes group was associated with a significantly higher rate of durable PVI. There was no difference regarding procedural adverse events between the two groups. CONCLUSION: As compared with the 3 minutes freeze, the TTI guided 4 minutes freeze is associated with a significantly higher rate of arrhythmia-free and durable PVI without compromising the safety profile, patients with persistent AF may benefit from the TTI guided 4 minutes freeze more pronouncedly.

Phrenic nerve injury in atrial fibrillation ablation using balloon catheters: Incidence, characteristics, and clinical recovery course.

AIMS: Systematic data on phrenic nerve palsy (PNP) associated with contemporary balloon ablation techniques (cryoballoon [CBA] vs laser balloon [LBA]) are sparse. We aimed to investigate the incidence, characteristics, and clinical recovery course in patients with PNP who underwent CBA or LBA. METHODS AND RESULTS: A total of 2433 consecutive patients who underwent balloon-based pulmonary vein isolation (CBA: n = 1720 and LBA: n = 713) were retrospectively identified. PNP was classified into (a) transient (recovery before discharge) or (b) persistent (within 6 months, 6-12 months, and >12 months) according to clinical recovery course. In general, PNP occurred significantly more often in CBA 71/1720 (4.2%) than LBA 11/713 (1.5%) (P = .003). The rate of transient PNP was significantly higher in CBA (3.0%, n = 45) than LBA (0.1%, n = 1, P = .004). The rate of persistent PNP did not significantly differ between two groups (CBA: 1.2% vs LBA: 1.4%, P = .89). The rate of persistent PNP which recovered within 6 months was similar (CBA: 17.4% vs LBA 18.2%, P = 1.000). However, the rates of persistent PNP which recovered within 6 to 12 months (CBA: 2.9% vs LBA 27.3%, P = .0171) and more than 12 months (CBA: 7.3% vs LBA 45.5%, P = .0034) were significantly higher in LBA. CONCLUSION: PNP occurred more often in CBA than LBA, however, the majority of PNP in CBA was transient whereas the majority of PNP in LBA was persistent. Either balloon technology is not superior in terms of long-term PNP.

Catheter ablation of atrial fibrillation using ablation index-guided high power (50 W) for pulmonary vein isolation with or without esophageal temperature probe (the AI-HP ESO II).

BACKGROUND: High-power, short-duration ablation for pulmonary vein isolation (PVI) in the treatment of atrial fibrillation (AF) facilitates the procedure and improve effectiveness; however, esophageal injury remains a safety concern. OBJECTIVE: The purpose of this study was to investigate the role of luminal esophageal temperature (LET) monitoring during high-power ablation for PVI in terms of endoscopic esophageal lesion. METHODS: Patients with symptomatic AF underwent ablation index-guided high-power (AI-HP) PVI (50 W; AI anterior wall/posterior wall: 550/400). In the first consecutive set of patients, an insulated esophageal temperature probe was used for LET monitoring (cutoff LET >39°C) (group A). In the second consecutive set of patients, the probe was not used (group B). All patients were scheduled to undergo esophageal endoscopy 1-3 days after ablation. RESULTS: A total of 120 patients (60 group A; 60 group B) were included in the study (mean age 67.8 years; 64% male). Baseline characteristics and procedural outcomes were similar between the 2 groups. Procedural PVI was achieved in all patients. First-pass PVI rate was 96.6%. Mean procedural radiofrequency (RF) time was 11.5 minutes, mean procedural time was 55.5 minutes, and fluoroscopic time was 5.6 minutes. Mean contact force at the LA posterior wall was 23 g, and mean RF ablation time at the LA posterior wall was 3.2 minutes. Two patients in group A and 1 patient in group B had endoscopic small esophageal lesions (P = .99). No serious procedural adverse events were observed. CONCLUSION: Among patients undergoing AI-HP (50 W) PVI, the incidences of ablation-related endoscopic esophageal lesion in patients with and those without use of a temperature probe for LET monitoring (cutoff 39°C) were comparably low.

EP Laboratory Nightmare: Catheter Ablation of Malignant Premature Ventricular Complex Complicated by Left Main Injury.

We present a case of ventricular fibrillation triggered by a premature ventricular complex. During ablation from the left coronary cusp, the ablation catheter dislodged inside left main coronary artery, thus resulting in cardiac arrest. We immediately performed angioplasty and stent implantation, and the procedure was accomplished with a guiding catheter left inside the vessel. (Level of Difficulty: Intermediate.).

CMR for Identifying the Substrate of Ventricular Arrhythmia in Patients With Normal Echocardiography.

OBJECTIVES: This study sought to determine whether cardiac magnetic resonance (CMR) may identify structural heart disease (SHD) in patients with ventricular arrhythmia who had echocardiography ruled out pathological findings. BACKGROUND: Approximately one-half of sudden cardiac deaths are attributable to malignant VA. Echocardiography is commonly used to identify SHD that is the most frequent substrate of VA. METHODS: A single-center prospective study was conducted in consecutive patients with significant VA, categorized as >1,000 but <10,000 ventricular ectopic beats [VEBs]/24 h; ≥10,000 VEBs/24 h; nonsustained ventricular tachycardia, sustained ventricular tachycardia, or a history of resuscitated cardiac arrest, and no pathological findings at echocardiography, requiring a clinically indicated CMR. Primary endpoint was CMR detection of SHD. Secondary endpoints were a composite of CMR detection of SHD and abnormal findings not specific for a definite SHD diagnosis. RESULTS: A total of 946 patients were enrolled (mean 41 ± 16 years of age; 64% men). CMR studies were used to diagnose SHD in 241 patients (25.5%) and abnormal findings not specific for a definite SHD diagnosis in 187 patients (19.7%). Myocarditis (n = 91) was the more frequent disease, followed by arrhythmogenic cardiomyopathy (n = 55), dilated cardiomyopathy (n = 39), ischemic heart disease (n = 22), hypertrophic cardiomyopathy (n = 13), congenital cardiac disease (n = 10), left ventricle noncompaction (n = 5), and pericarditis (n = 5). The strongest univariate and multivariate predictors of SHD on CMR images were chest pain (odds ratios [OR]: 2.52 and 2.38, respectively) and sustained ventricular tachycardia (ORs: 2.67 and 2.23, respectively). CONCLUSIONS: SHD was able to be identified on CMR imaging in a sizable number of patients with significant VA and completely normal echocardiography. Chest pain and sustained ventricular tachycardia were the strongest predictors of positive CMR imaging results.

Diagnostic performance of coronary CT angiography carried out with a novel whole-heart coverage high-definition CT scanner in patients with high heart rate.

BACKGROUND: Aim of the study was to evaluate image quality, radiation exposure and diagnostic accuracy of coronary CT angiography (CCTA) performed with a novel cardiac CT scanner in patients with very high heart rate (HR). METHODS: We prospectively enrolled 202 patients (111 men, mean age 66±8years) with suspected coronary artery disease who underwent CCTA with a whole-organ volumetric CT scanner. The HR during the scan was ≥80bpm in 100 patients (Group 1), while it was ≤65bpm in the remaining 102 patients (Group 2). In all patients, image quality score and coronary interpretability were evaluated and effective dose (ED) was recorded. In 86 of the 202 enrolled patients (40 patients in Group 1, 46 patients in Group 2) who were referred for a clinically indicated invasive coronary angiography (ICA) within 6months, diagnostic accuracy of CCTA vs. ICA was evaluated. RESULTS: Mean image quality and coronary interpretability were very high in both Groups (Likert=3.35 vs. 3.39 and 97.3% [1542/1584 segments] and 98% [1569/1600 segments] in Group 1 and Group 2, respectively). Mean ED was lower in Group 2 (1.1±0.5mSv) compared to Group 1 (2.9±1.6mSv). In Group 1, sensitivity and specificity of CCTA for detection of >50% stenosis vs. ICA were 95.2% and 98.9% in a segment-based analysis and 100% and 81.8% in a patient-based analysis, respectively. CONCLUSIONS: The whole organ high-definition CT scanner allows evaluating coronary arteries in patients with high HR with excellent image quality, coronary interpretability and low radiation exposure.