AI Cardiac MRI Scar Analysis Aids Prediction of Major Arrhythmic Events in the Multicenter DERIVATE Registry.

Background Scar burden with late gadolinium enhancement (LGE) cardiac MRI (CMR) predicts arrhythmic events in patients with postinfarction in single-center studies. However, LGE analysis requires experienced human observers, is time consuming, and introduces variability. Purpose To test whether postinfarct scar with LGE CMR can be quantified fully automatically by machines and to compare the ability of LGE CMR scar analyzed by humans and machines to predict arrhythmic events. Materials and Methods This study is a retrospective analysis of the multicenter, multivendor CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy (DERIVATE) registry. Patients with chronic heart failure, echocardiographic left ventricular ejection fraction (LVEF) of less than 50%, and LGE CMR were recruited (from January 2015 through December 2020). In the current study, only patients with ischemic cardiomyopathy were included. Quantification of total, dense, and nondense scars was carried out by two experienced readers or a Ternaus network, trained and tested with LGE images of 515 and 246 patients, respectively. Univariable and multivariable Cox analyses were used to assess patient and cardiac characteristics associated with a major adverse cardiac event (MACE). Area under the receiver operating characteristic curve (AUC) was used to compare model performances. Results In 761 patients (mean age, 65 years ± 11, 671 men), 83 MACEs occurred. With use of the testing group, univariable Cox-analysis found New York Heart Association class, left ventricle volume and/or function parameters (by echocardiography or CMR), guideline criterion (LVEF of ≤35% and New York Heart Association class II or III), and LGE scar analyzed by humans or the machine-learning algorithm as predictors of MACE. Machine-based dense or total scar conferred incremental value over the guideline criterion for the association with MACE (AUC: 0.68 vs 0.63, P = .02 and AUC: 0.67 vs 0.63, P = .01, respectively). Modeling with competing risks yielded for dense and total scar (AUC: 0.67 vs 0.61, P = .01 and AUC: 0.66 vs 0.61, P = .005, respectively). Conclusion In this analysis of the multicenter CarDiac MagnEtic Resonance for Primary Prevention Implantable CardioVerter DebrillAtor ThErapy (DERIVATE) registry, fully automatic machine learning-based late gadolinium enhancement analysis reliably quantifies myocardial scar mass and improves the current prediction model that uses guideline-based risk criteria for implantable cardioverter defibrillator implantation. ClinicalTrials.gov registration no.: NCT03352648 Published under a CC BY 4.0 license. Supplemental material is available for this article.

Outcomes of transvenous lead extraction of very old leads using bidirectional rotational mechanical sheaths: Results of a multicentre study.

INTRODUCTION: Lead dwell time >10 years is a recognized predictor for transvenous lead extraction (TLE) failure and complications. Data on the efficacy and safety of TLE using the bidirectional rotational mechanical sheaths in patients with very old leads are lacking. In this multicenter study, we reported the outcomes of transvenous rotational mechanical lead extraction in patients with leads implanted for ≥10 years. METHODS: A total of 441 leads (median: 159 months [135-197]; range: 120-487) in 189 consecutive patients were removed with the Evolution RL sheaths (Cook Medical, Bloomingtom, IN, USA) and mechanical ancillary tools supporting the procedures. RESULTS: The main indication for TLE was infection in 74% of cases. Complete procedural success rate, clinical success rate, per lead were 94.8% and 98.2%, respectively. Failure of lead extraction was seen in 1.8% of leads. The additional use of a snare via the femoral approach was required in 9% of patients. Lead dwell time was the only predictor of incomplete led removal (odds ratio: 1.009; 95% confidence interval [CI]: 1.003-1.014; p = .002). Four major complication (2%) were encountered. During a mean time follow-up of 31 ± 27 months, 21 patients (11%) died. No procedure-related mortality occurred. Predictors of mortality included severe left ventricular systolic dysfunction (hazard ratio [HR]: 8.06; 95% CI: 2.99-21.73; p = .001), TLE for infection (HR: 8.0; 95% CI: 1.04-62.5; p = .045), diabetes (HR: 3.7; 95% CI: 1.48-9.5; p = .005), and previous systemic infection (HR: 3.1; 95% CI: 1.17-8.24; p = .022). Incomplete lead removal or failure lead extraction did not impact on survival during follow-up. CONCLUSION: Our findings demonstrated that the use of bidirectional rotational TLE mechanical sheaths combined with different mechanical tools and femoral approach allows reasonable success and safety in patients with very old leads at experienced specialized centers.

Cardiac magnetic resonance imaging of arrhythmogenic cardiomyopathy: evolving diagnostic perspectives.

Arrhythmogenic cardiomyopathy (ACM) is a genetically determined heart muscle disease characterized by fibro-fatty myocardial replacement, clinically associated with malignant ventricular arrhythmias and sudden cardiac death. Originally described a disease with a prevalent right ventricular (RV) involvement, subsequently two other phenotypes have been recognized, such as the left dominant and the biventricular phenotypes, for which a recent International Expert consensus document provided upgrade diagnostic criteria (the 2020 "Padua Criteria"). In this novel workup for the diagnosis of the entire spectrum of phenotypic variants of ACM, including left ventricular (LV) variants, cardiac magnetic resonance (CMR) has emerged as the cardiac imaging technique of choice, due to its capability of detailed morpho-functional and tissue characterization evaluation of both RV and LV. In this review, the key role of CMR in the diagnosis of ACM is outlined, including the supplemental value for the characterization of the disease variants. An ACM-specific CMR study protocol, as well as strengths and weaknesses of each imaging technique, is also provided. KEY POINTS: • Arrhythmogenic cardiomyopathy includes three different phenotypes: dominant right, biventricular, and dominant left. • In 2020, diagnostic criteria have been updated and cardiac magnetic resonance has emerged as the cardiac imaging technique of choice. • This aim of this review is to provide an update of the current state of art regarding the use of CMR in ACM, with a particular focus on novel diagnostic criteria, CMR protocols, and prognostic significance of CMR findings in ACM.

Left atrial expansion index measured with cardiovascular magnetic resonance estimates pulmonary capillary wedge pressure in dilated cardiomyopathy.

BACKGROUND: Pulmonary capillary wedge pressure (PCWP) assessment is fundamental for managing dilated cardiomyopathy (DCM) patients. Although cardiovascular magnetic resonance (CMR) has become the gold-standard imaging technique for evaluating cardiac chamber volume and function, PCWP is not routinely assessed with CMR. Therefore, this study aimed to validate the left atrial expansion index (LAEI), a LA reservoir function parameter able to estimate filling pressure with echocardiography, as a novel CMR-measured parameter for non-invasive PCWP estimation in DCM patients. METHODS: We performed a retrospective, single-center, cross-sectional study. We included electively admitted DCM patients referred to our tertiary center for further diagnostic evaluation that underwent a clinically indicated right heart catheterization (RHC) and CMR within 24 h. PCWP invasively measured during RHC was used as the reference. LAEI was calculated from CMR-measured LA maximal and minimal volumes as LAEI = ( (LAVmax-LAVmin)/LAVmin) × 100. RESULTS: We enrolled 126 patients (47 ± 14 years; 68% male; PCWP = 17 ± 9.3 mmHg) randomly divided into derivation (n = 92) and validation (n = 34) cohorts with comparable characteristics. In the derivation cohort, the log-transformed (ln) LAEI showed a strong linear correlation with PCWP (r = 0.81, p < 0.001) and remained a strong independent PCWP determinant over clinical and conventional CMR parameters. Moreover, lnLAEI accurately identified PCWP ≥ 15 mmHg (AUC = 0.939, p < 0.001), and the optimal cut-off identified (lnLAEI ≤ 3.85) in the derivation cohort discriminated PCWP ≥ 15 mmHg with 82.4% sensitivity, 88.2% specificity, and 85.3% accuracy in the validation cohort. Finally, the equation PCWP = 52.33- (9.17xlnLAEI) obtained from the derivation cohort predicted PCWP (-0.1 ± 5.7 mmHg) in the validation cohort. CONCLUSIONS: In this cohort of DCM patients, CMR-measured LAEI resulted in a novel and useful parameter for non-invasive PCWP evaluation.

Outcomes of transvenous lead extraction in octogenarians using bidirectional rotational mechanical sheaths.

BACKGROUND: Outcomes of transvenous lead extraction (TLE) are well reported in the general population, However, data on safety, efficacy of TLE in octogenarians with a long lead dwell time, using powered extraction tools are limited. The aim of this multicenter study was to evaluate the safety, effectiveness of TLE in octogenarians using the bidirectional rotational mechanical sheaths and mid-term outcome after TLE. METHODS: The study population comprised 83 patients (78.3% male; mean age 85 ± 3 years; [range 80-94 years]) with 181 target leads. All the leads (mean implant duration 112 ± 77 months [range 12-377]) were extracted exclusively using the Evolution RL sheaths (Cook Medical, Bloomington, IN, USA). RESULTS: The main indication for TLE was infection in 84.3% of cases. Complete procedural success rate, clinical success rate, per lead were 93.9% and 98.3%, respectively. Failure of lead extraction was seen in 1.7% of leads. The additional use of a snare was required in 8.4% of patients. Major complications occurred in one patient (1.2%). Thirty-day mortality after TLE was 6%. During a mean time follow-up of 22 ± 21 months, 24 patients (29%) died. No procedure-related mortality occurred. Predictors of mortality included ischemic cardiomyopathy (HR 4.35; 95% CI 1.87-10.13; p = .001), left ventricularejection fraction ≤35% (HR 7.89; 95% CI 3.20-19.48; p < .001), and TLE for systemic infection (HR 4.24; 95% CI 1.69-10.66; p = .002). CONCLUSIONS: At experienced centers bidirectional rotational mechanical sheaths combined with different mechanical tools and femoral approach allowreasonable success and safety in octogenarian with long lead dwell time. Patient's age should not influence the decision to extract or not the leads, although the 30-day and mid-term mortality are significant, especially in the present of specific comorbidities.

Scarring/arrhythmogenic cardiomyopathy.

The designation of 'arrhythmogenic cardiomyopathy' reflects the evolving concept of a heart muscle disease affecting not only the right ventricle (ARVC) but also the left ventricle (LV), with phenotypic variants characterized by a biventricular (BIV) or predominant LV involvement (ALVC). Herein, we use the term 'scarring/arrhythmogenic cardiomyopathy (S/ACM)' to emphasize that the disease phenotype is distinctively characterized by loss of ventricular myocardium due to myocyte death with subsequent fibrous or fibro-fatty scar tissue replacement. The myocardial scarring predisposes to potentially lethal ventricular arrhythmias and underlies the impairment of systolic ventricular function. S/ACM is an 'umbrella term' which includes a variety of conditions, either genetic or acquired (mostly post-inflammatory), sharing the typical 'scarring' phenotypic features of the disease. Differential diagnoses include 'non-scarring' heart diseases leading to either RV dilatation from left-to-right shunt or LV dilatation/dysfunction from a dilated cardiomyopathy. The development of 2020 upgraded criteria ('Padua criteria') for diagnosis of S/ACM reflected the evolving clinical experience with the expanding spectrum of S/ACM phenotypes and the advances in cardiac magnetic resonance (CMR) imaging. The Padua criteria aimed to improve the diagnosis of S/ACM by incorporation of CMR myocardial tissue characterization findings. Risk stratification of S/ACM patients is mostly based on arrhythmic burden and ventricular dysfunction severity, although other ECG or imaging parameters may have a role. Medical therapy is crucial for treatment of ventricular arrhythmias and heart failure. Implantable cardioverter defibrillator (ICD) is the only proven life-saving treatment, despite its significant morbidity because of device-related complications and inappropriate shocks. Selection of patients who can benefit the most from ICD therapy is one of the most challenging issues in clinical practice.

The valuable interaction among cardiac surgeon and electrophysiologist for transvenous rotational mechanical lead extraction.

BACKGROUND: Recent studies have shown that Evolution RL bidirectional rotational mechanical sheath (Cook Medical, USA) is an effective and safe technique for transvenous lead extraction (TLE). We reported our experience with the bidirectional rotational mechanical tools using a multidisciplinary approach highlighting the value of a joint cardiac surgeon and electrophysiologist collaboration. METHODS: The study population comprised 84 patients (77% male; mean age 65 ± 18 years) undergoing TLE. After a multidisciplinary evaluation, a combined procedure was considered. RESULTS: The main indication for TLE was infection in 54 cases (64%). Overall, 152 leads were extracted with a mean implant duration of 94 ± 63 months (range 12-421). Complete procedural success rate, clinical success rate, and lead removal with clinical success rate were 91.6% (77/84), 97.6% (82/84), and 98.6% (150/152), respectively. Eighteen combined procedures were performed in 12 patients (14%), such as "hybrid approach" (n = 2) or TLE concomitant to: 1) transcatheter aspiration procedure for large vegetation (n = 8); 2) left ventricular assistance device implantation as bridge to cardiac transplantation (n = 1); 3) permanent pacing with epicardial leads (n = 6); 4) tricuspid valve replacement (n = 1). One major complication (1.2%) and 11 (13%) minor complications were encountered. No injury to the superior vena cava occurred and no procedure-related deaths were reported. During a mean time follow-up of 21 ± 18 months, 17 patients (20%) died. They were more often diabetics (p = .02), and they underwent TLE more often for infection (p = .004). CONCLUSIONS: Our results support the finding that excellent outcomes can be achieved in performing TLE of chronically implanted leads by using the Evolution RL bidirectional rotational mechanical sheath and a multidisciplinary team approach involving both electrophysiologist and cardiac surgeon as first line operators.

'Hot phase' clinical presentation in arrhythmogenic cardiomyopathy.

AIMS: The aim of this study is to evaluate the clinical features of patients affected by arrhythmogenic cardiomyopathy (AC), presenting with chest pain and myocardial enzyme release in the setting of normal coronary arteries ('hot phase'). METHODS AND RESULTS: We collected detailed anamnestic, clinical, instrumental, genetic, and histopathological findings as well as follow-up data in a series of AC patients who experienced a hot phase. A total of 23 subjects (12 males, mean age at the first episode 27 ± 16 years) were identified among 560 AC probands and family members (5%). At first episode, 10 patients (43%) already fulfilled AC diagnostic criteria. Twelve-lead electrocardiogram recorded during symptoms showed ST-segment elevation in 11 patients (48%). Endomyocardial biopsy was performed in 11 patients, 8 of them during the acute phase showing histologic evidence of virus-negative myocarditis in 88%. Cardiac magnetic resonance was performed in 21 patients, 12 of them during the acute phase; oedema and/or hyperaemia were detected in 7 (58%) and late gadolinium enhancement in 11 (92%). At the end of follow-up (mean 17 years, range 1-32), 12 additional patients achieved an AC diagnosis. Genetic testing was positive in 77% of cases and pathogenic mutations in desmoplakin gene were the most frequent. No patient complained of sustained ventricular arrhythmias or died suddenly during the 'hot phase'. CONCLUSION: 'Hot phase' represents an uncommon clinical presentation of AC, which often occurs in paediatric patients and carriers of desmoplakin gene mutations. Tissue characterization, family history, and genetic test represent fundamental diagnostic tools for differential diagnosis.

CarDiac magnEtic Resonance for prophylactic Implantable-cardioVerter defibrillAtor ThErapy in Non-Ischaemic dilated CardioMyopathy: an international Registry.

AIMS: The aim of this registry was to evaluate the additional prognostic value of a composite cardiac magnetic resonance (CMR)-based risk score over standard-of-care (SOC) evaluation in a large cohort of consecutive unselected non-ischaemic cardiomyopathy (NICM) patients. METHODS AND RESULTS: In the DERIVATE registry (www.clinicaltrials.gov/registration: RCT#NCT03352648), 1000 (derivation cohort) and 508 (validation cohort) NICM patients with chronic heart failure (HF) and left ventricular ejection fraction <50% were included. All-cause mortality and major adverse arrhythmic cardiac events (MAACE) were the primary and secondary endpoints, respectively. During a median follow-up of 959 days, all-cause mortality and MAACE occurred in 72 (7%) and 93 (9%) patients, respectively. Age and >3 segments with midwall fibrosis on late gadolinium enhancement (LGE) were the only independent predictors of all-cause mortality (HR: 1.036, 95% CI: 1.0117-1.056, P < 0.001 and HR: 2.077, 95% CI: 1.211-3.562, P = 0.008, respectively). For MAACE, the independent predictors were male gender, left ventricular end-diastolic volume index by CMR (CMR-LVEDVi), and >3 segments with midwall fibrosis on LGE (HR: 2.131, 95% CI: 1.231-3.690, P = 0.007; HR: 3.161, 95% CI: 1.750-5.709, P < 0.001; and HR: 1.693, 95% CI: 1.084-2.644, P = 0.021, respectively). A composite clinical and CMR-based risk score provided a net reclassification improvement of 63.7% (P < 0.001) for MAACE occurrence when added to the model based on SOC evaluation. These findings were confirmed in the validation cohort. CONCLUSION: In a large multicentre, multivendor cohort registry reflecting daily clinical practice in NICM work-up, a composite clinical and CMR-based risk score provides incremental prognostic value beyond SOC evaluation, which may have impact on the indication of implantable cardioverter-defibrillator implantation.

Appropriate use criteria for cardiovascular magnetic resonance imaging (CMR): SIC-SIRM position paper part 1 (ischemic and congenital heart diseases, cardio-oncology, cardiac masses and heart transplant).

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.

Axillary vein access for permanent pacemaker and implantable cardioverter defibrillator implantation: Fluoroscopy compared to ultrasound.

BACKGROUND: Axillary vein access (AVA) using fluoroscopic landmarks is an effective and safe approach for cardiac implantable electronic devices (CIEDs) implantation. However, it may result in a higher radiation exposure. Ultrasound-guided axillary access (USAA) is an effective alternative technique to conventional subclavian access for CIEDs implantation. Studies comparing USAA and AVA using fluoroscopic landmarks are lacking. The purpose of this study was to compare the safety, efficacy, and radiation exposure data of the USAA approach with the AVA using fluoroscopic landmarks. METHODS: The study population included 95 consecutive patients (61% male, median age 78 years [71-85 years]) referred for CIEDs implantation using AVA with fluoroscopic landmark (n = 46) or USAA (n = 49). Baseline characteristics and radiation exposure data (Air-Kerma [mGy], DAP [Gy-cm2 ], fluoroscopy time [seconds], and X-rays emission time [seconds]) were compared according to the technique used for the AVA. RESULTS: Axillary vein was successfully accessed in 45 of 49 (92%) patients using ultrasound and in 42 of 46 (91%) patients using fluoroscopic landmarks (P = 1.00). Air-Kerma, DAP, fluoroscopy time, and X-rays emission time were shorter for USAA group compared with AVA using fluoroscopic landmarks (11 mGy [8-20] vs 37 mGy [24-81], P < .00001; 3 Gy-cm2 [2-5] vs 10 Gy-cm2 [6-16], P < .00001; 97 seconds [62-163] vs 271 seconds [185-365], P < .00001; and 7 seconds [4-10] vs 21 seconds [13-39], P < .00001). There were no significant differences between the two groups in median implant procedure time (P = .55). We did not encounter any acute or long-term complications in both groups. CONCLUSIONS: Ultrasound-guided axillary vein cannulation for CIEDs implantation is a feasible and safe alternative approach and offers a significant reduction in fluoroscopy times without increasing procedural time.

Multicentre experience with the second-generation subcutaneous implantable cardioverter defibrillator and the intermuscular two-incision implantation technique.

INTRODUCTION: The recently developed second-generation subcutaneous implantable cardioverter defibrillator (S-ICD) and the intermuscular two-incision implantation technique demonstrate potential favorable features that reduce inappropriate shocks and complications. However, data concerning large patient populations are lacking. The aim of this multicentre prospective study was to evaluate the safety and outcome of second-generation S-ICD using the intermuscular two-incision technique in a large population study. METHODS AND RESULTS: The study population included 101 consecutive patients (75% male; mean age, 45 ± 13 years) who received second-generation S-ICD (EMBLEM; Boston Scientific, Marlborough, MA) implantation using the intermuscular two-incision technique as an alternative to the standard implantation technique. Twenty nine (29%) patients were implanted for secondary prevention. Twenty four (24%) patients had a previously implanted transvenous ICD. All patients were implanted without any procedure-related complications. Defibrillation testing was performed in 80 (79%) patients, and ventricular tachycardia was successfully converted at less than or equal to 65 J in 98.75% (79/80) of patients without pulse generator adjustments. During a median follow-up of 21 ± 10 months, no complications requiring surgical revision or local or systemic device-related infections were observed. Ten patients (9.9%) received appropriate and successful shocks for ventricular arrhythmias. Three (2.9%) patients experienced inappropriate shocks due to oversensing the cardiac signal (n = 1), noncardiac signal (n = 1), and a combination of both cardiac and noncardiac signals (n = 1), with one patient requiring device explantation. No patients required device explantation due to antitachycardia pacing indications. CONCLUSIONS: According to our multicentre study, second-generation S-ICD implanted with the intermuscular two-incision technique is an available safe combination and appears to be associated with a low risk of complications, such as inappropriate shocks.

Multicenter experience with the Evolution RL mechanical sheath for lead extraction using a stepwise approach: Safety, effectiveness, and outcome.

BACKGROUND: In addition to the Evolution RL sheath, tools by Cook Medical (Bloomington, IN, USA), supporting lead extraction (LE), are available. Data on their use are not reported in detail in previous studies. Moreover, data regarding outcome are lacking. The aim was to evaluate the safety and effectiveness of the Evolution sheath (Evolution RL and Evolution Shortie, Cook Medical) by using a stepwise approach with the available extraction tools and the outcome. METHODS: A total of 393 leads in 198 consecutive patients were removed with the Evolution RL sheath and ancillary tools using a stepwise approach. RESULTS: The main indication for LE was infection in 125 (63.1%) cases. The mean implant duration was 95.4 ± 59.7 months. According to our stepwise approach, the Evolution Shortie RL sheath was used in all cases and complete LE was achieved in 24 (12.2%) cases. The Evolution RL was used in 174 (87.8%) cases and the SteadySheath Evolution tissue stabilization sheath (Cook Medical) in 87 (44%) because of tenacious fibrosis anchored targeted leads. Compression coil (OneTie, Cook Medical) was used in 141 (71%) cases. Complete procedural success rate, clinical success rate, and lead removal with clinical success rate were 97%, 99%, and 99.5%, respectively. One major complication (0.5%) and 10 (5%) minor complications were encountered. During a mean time follow-up of 12 ± 9 months, 14 (7%) patients died. Predictors of mortality included impaired renal function (HR 5.7; 95% CI 1.9-17.6; P = 0.002), extraction because of infection (hazard ratio [HR] 4.0; 95% confidence interval [CI] 1-18.1; P = 0.045), and diabetes (HR 3.2; 95% CI 1.1-9.8; P = 0.036). CONCLUSIONS: Lead extraction using the Evolution RL bidirectional rotational mechanical sheath and ancillary tools in a systematic stepwise approach was effective and safe.

Implantable cardioverter-defibrillator in the elderly: Predictors of appropriate interventions and mortality at 12-month follow-up.

BACKGROUND: The effectiveness of implantable cardioverter-defibrillator (ICD) in the elderly is uncertain, given their competing risk of nonarrhythmic death. Guidelines state that an ICD should be implanted if the expectation of survival is at least 1 year. However, survival is not easy to predict in elderly patients with severe cardiac disease. AIM: To assess 12-month survival after ICD implantation in patients aged ≥75 years, to identify predictors of 12-month mortality, and to evaluate the incidence of ICD therapy during follow-up. METHODS: We retrospectively analyzed all clinical, instrumental, and survival data of patients ≥75 years old who received an ICD in our center from 2000 to 2013. RESULTS: We included 127 patients (mean age 78 years). ICD was implanted for primary prevention in 61%. The 12-month survival rate was 87.4%. At both univariate and multivariate analyses, left ventricular ejection fraction (EF) ≤ 25%, and moderate to severe impaired renal function (IRF) independently predicted 12-month mortality that was as high as 45.5% in patients with both risk factors. During a median follow-up of 38 months, 30 patients (23.6%) received ≥1 appropriate ICD interventions, but only 3.1% of shocks occurred during the first year, and none in the subgroup of patients with EF ≤ 25% and IRF. CONCLUSION: Twelve-month survival in elderly patients after ICD implantation is good and the indication for ICD should not be based on age alone. However, the subgroup with EF ≤ 25% and IRF showed a high 12-month nonarrhythmic mortality and did not benefit from ICD implantation.

Arrhythmic Mitral Valve Prolapse and Sudden Cardiac Death.

BACKGROUND: Mitral valve prolapse (MVP) may present with ventricular arrhythmias and sudden cardiac death (SCD) even in the absence of hemodynamic impairment. The structural basis of ventricular electric instability remains elusive. METHODS AND RESULTS: The cardiac pathology registry of 650 young adults (≤40 years of age) with SCD was reviewed, and cases with MVP as the only cause of SCD were re-examined. Forty-three patients with MVP (26 females; age range, 19-40 years; median, 32 years) were identified (7% of all SCD, 13% of women). Among 12 cases with available ECG, 10 (83%) had inverted T waves on inferior leads, and all had right bundle-branch block ventricular arrhythmias. A bileaflet involvement was found in 70%. Left ventricular fibrosis was detected at histology at the level of papillary muscles in all patients, and inferobasal wall in 88%. Living patients with MVP with (n=30) and without (control subjects; n=14) complex ventricular arrhythmias underwent a study protocol including contrast-enhanced cardiac magnetic resonance. Patients with either right bundle-branch block type or polymorphic complex ventricular arrhythmias (22 females; age range, 28-43 years; median, 41 years), showed a bileaflet involvement in 70% of cases. Left ventricular late enhancement was identified by contrast-enhanced cardiac magnetic resonance in 93% of patients versus 14% of control subjects (P<0.001), with a regional distribution overlapping the histopathology findings in SCD cases. CONCLUSIONS: MVP is an underestimated cause of arrhythmic SCD, mostly in young adult women. Fibrosis of the papillary muscles and inferobasal left ventricular wall, suggesting a myocardial stretch by the prolapsing leaflet, is the structural hallmark and correlates with ventricular arrhythmias origin. Contrast-enhanced cardiac magnetic resonance may help to identify in vivo this concealed substrate for risk stratification.

Relationship between T-wave inversion and transmural myocardial edema as evidenced by cardiac magnetic resonance in patients with clinically suspected acute myocarditis: clinical and prognostic implications.

BACKGROUND: The pathophysiologic mechanisms and the prognostic meaning of electrocardiographic (ECG) T-wave inversion (TWI) occurring in a subgroup of patients with clinically suspected acute myocarditis remain to be elucidated. Contrast-enhanced cardiac magnetic resonance (CMR) offers the potential to identify myocardial tissue changes such as edema and/or fibrosis which may underlie TWI. METHODS AND RESULTS: We studied 76 consecutive patients (median age 34years) with clinically suspected acute myocarditis, using a comprehensive CMR protocol which included T2 weighted sequences for myocardial edema. At the time of CMR, TWI was observed in 21 (27%) patients. There was a statistically significant association of TWI with the median number of left ventricular (LV) segments showing both any pattern of myocardial edema (transmural and non-transmural) [5 (3-7) vs. 3 (2-4); p=0.015] and myocardial late-gadolinium-enhancement [4 (3-7) vs. 3 (2-4); p=0.002]. Transmural myocardial edema involving ≥2 LV segments was found in 17/21 (81%) patients with TWI versus 13/55 (24%) patients without TWI (p<0.001) and remained the only independent predictor of TWI at multivariable analysis (OR=9.96; 95%CI=2.71-36.6; p=0.001). Overall, topographic concordance between the location of TWI across the ECG leads and the regional distribution of transmural myocardial edema was 88%. There was no association between acute TWI and reduced LV ejection fraction (<55%) at 6-months of follow-up. CONCLUSIONS: This is the first study to demonstrate an association between LV transmural myocardial edema as evidenced by CMR sequences and TWI in clinically suspected acute myocarditis. As an expression of reversible myocardial edema, development of TWI during the acute disease phase was not a predictor of LV systolic dysfunction at follow-up.

Incidence and characteristics of phrenic nerve palsy following pulmonary vein isolation with the second-generation as compared with the first-generation cryoballoon in 360 consecutive patients.

AIMS: The second-generation cryoballoon (CB2) with increased surface cooling has recently become available. The aim was to investigate the incidence and characteristics of phrenic nerve palsy (PNP) during pulmonary vein isolation (PVI) using the CB2 as compared with the first-generation balloon (CB1). METHODS AND RESULTS: A total of 360 consecutive patients with atrial fibrillation underwent PVI with the CB1 (106 patients) or the CB2 (254 patients). Right PN function was monitored by continuous stimulation and palpation during septal PV ablation. Persistent PNP (present at discharge) occurred in 2.8 and 1.9% (P = 0.63) of patients, transient PNP (full recovery before discharge) in 5.9 and 3.8% (P = 0.41) of patients in the CB2 and CB1 group, respectively. Phrenic nerve palsy during ablation at the right inferior PV was observed in 0% (CB1) and 4.3% (CB2, P = 0.03) of patients. Using the CB2, a trend of reduced incidence of persistent PNP over quartiles of consecutive patients was observed [4.8% (Q1) vs. 0% (Q4); P = 0.077]. At the culprit PV, PNP occurred after 3.5 ± 2.1 (CB1) and 1.1 ± 0.4 applications (CB2; P = 0.036). Complete recovery of PN function occurred after 29 ± 11 (CB1) and 259 ± 137 days (CB2; P = 0.004). CONCLUSIONS: The rate of transient/persistent PNP associated with the use of the CB2 was 5.9 and 2.8%, respectively. Time to restitution of PN function was longer using the CB2.

Ventricular couplets but not isolated extrasystoles induce a "female" sustained, supraventricular tachycardia. What is the mechanism?

This is the case of a 28-year-old woman with sustained supraventricular tachycardia induced only by monomorphic ventricular couplets but not by isolated extrasystoles. The careful examination of electrocardiogram (ECG) was able to identify the mechanism of the tachycardia in the absence of electrophysiologic investigation. The tachycardia resulted sustained and symptomatic only during periods.

Incidence, management, and prevention of right ventricular perforation by pacemaker and implantable cardioverter defibrillator leads.

BACKGROUND: Cardiac perforation of the right ventricle (RV) is a rare but potentially life-threatening complication of both pacemaker (PM) and implantable cardioverter defibrillator (ICD) implant. Appropriate management is still uncertain. We assessed the incidence of subacute (24 hours-1 month) or delayed (>1 month) cardiac perforation by RV lead and the results of percutaneous lead extraction. METHOD: The study population included all patients diagnosed with subacute or delayed RV-lead perforation during the period 2007-2013. The incidence of perforation according to device type and fixation mechanism was calculated. The outcome of the percutaneous approach, consisting of lead extraction by simple traction, was assessed. RESULTS: Cardiac perforation was diagnosed in 14 (eight females, mean age 71 [range 47-83] years) patients out of 3,815 who received an RV-lead implant (0.4%). The overall incidence of RV-lead perforation was similar between ICD (0.3%) and PM (0.4%) implants (P = 1.0) and between active (0.5%) and passive (0.3%) fixation leads (P = 0.3). All perforating leads were originally placed at the RV apex. Five patients were asymptomatic, but all presented altered lead electrical parameters. Surgical removal of the lead was performed in one patient while in the remaining the leads were successfully extracted by direct manual traction in the absence of any complications. In all patients, new active fixation leads were positioned in the RV septum and the follow-up (42 ± 27 months) was uneventful. CONCLUSIONS: RV perforation is a rare complication of both PM and ICD implants, regardless of the lead fixation mechanism. In most patients, percutaneous lead extraction is a safe and effective management approach.