Non-transmural myocardial infarction associated with regional contractile function is an independent predictor of positive outcome: an integrated approach to myocardial viability

Background Cardiovascular magnetic resonance permits assessment of irreversible myocardial fibrosis and contractile function in patients with previous myocardial infarction. We aimed to assess the prognostic value of myocardial fibrotic tissue with preserved/restored contractile activity. Methods In 730 consecutive myocardial infarction patients (64 ± 11 years), we quantified left ventricular (LV) end-diastolic (EDV) and end-systolic (ESV) volumes, ejection fraction (EF), regional wall motion (WM) (1 normal, 2 hypokinetic, 3 akinetic, 4 dyskinetic), and WM score index (WMSI), and measured the transmural (1–50 and 51–100) and global extent of the infarct scar by late gadolinium enhancement (LGE). Contractile fibrotic (CT-F) segments were identified as those showing WM-1 and WM-2 with LGE ≤ or ≥ 50%. Results During follow-up (median 2.5, range 1–4.7 years), cardiac events (cardiac death or appropriate implantable defibrillator shocks) occurred in 123 patients (17%). At univariate analysis, age, LVEDV, LVESV, LVEF, WMSI, extent of LGE, segments with transmural extent > 50%, and CT-F segments were associated with cardiac events. At multivariate analysis, age > 65 years, LVEF < 30%, WMSI > 1.7, and dilated LVEDV independently predicted cardiac events, while CT-F tissue was the only independent predictor of better outcome. After adjustment for LVEF < 30% and LVEDV dilatation, the presence of CT-F tissue was associated with good prognosis. Conclusions In addition to CMR imaging parameters associated with adverse outcome (severe LV dysfunction, poor WM, and dilated EDV), the presence of fibrotic myocardium showing contractile activity in patients with previous myocardial infarction yields a beneficial effect on patient survival.

Inappropriate shocks from a transvenous implantable defibrillator caused by atrial fibrillation and a missed atrial septal defect in a patient with a modified Bentall procedure

Background Inappropriate shocks have been reported in approximately 1/3 of patients with implantable cardiac defibrillators (ICDs). We report an unusual case of inappropriate ICD shocks due to atrial fibrillation (AF) caused by a missed atrial septal defect (ASD) in a patient with a modified Bentall procedure. Case summary A 67-year-old Caucasian male, with an ICD and a history of a modified Bentall procedure 24 years ago, reported to our outpatient clinic with recurrent inappropriate ICD shocks due to episodes of fast AF. The transthoracic echocardiographic exam revealed 2 large aneurysms at the ostia of the coronary arteries. We performed further evaluation with transesophageal echocardiogram (TOE) and computed tomography (CT) angiography. The aneurysms measured on CT were 3.14*2.29 cm on the right ostium and 1.9*0.99 cm on the left. A large secundum-type atrial septal defect (ASD) of 1.5 cm was revealed that was missed in all previous echocardiographic studies. The therapeutic options of surgical closure of the ASD and repair of the aneurysms or a more conservative approach with percutaneous closure of the ASD and closer follow-up were discussed with the patient. The patient declined the surgical option due to high complication risk, and closure of the ASD with an Amplatzer device was performed 3 months later. A 3 -year Follow-up was uneventful. Conclusion It is of major importance to comprehensively and thoroughly assess patients before and after a surgical intervention to not miss other treatable conditions preoperatively and complications in the postoperative period.

Most remote monitoring alerts about atrial fibrillation are not relevant to identify clinically significant events: proposal of a new approach

Background Cardiac Implantable Electronic Devices (CIEDs) are an important tool for detecting Atrial Fibrillation (AF) in implanted patients. However AF burden values and notifications emitted by the manufacturer's platforms are not directly related to the standard classification of AF types (paroxysmal, persistent or permanent) that are used in daily practice. Moreover, AF alerts represent the most frequent notifications for implanted patients resulting in a time-consuming review for healthcare professionals. Purpose This study intends to compare the manufacturers' atrial burden related notifications in remotely monitored (RM) patients to the detection of clinically significant events with a new proprietary algorithm. Methods From 2017 to 2020, all RM patients from 57 centers with daily atrial burden measurements available for at least 30 days and at least one atrial burden related alert were enrolled. All atrial burden related alerts emitted by the manufacturers' platforms were compared to the following clinically significant events (based on the standard classification) detected by a new proprietary algorithm: “1st recorded AT/AF episode”, “paroxysmal AF”, “increasing paroxysmal AF”, “persistent AF”, and “end of persistent AF”. Results This multicentric retrospective study analyzed, between 01/2017 and 10/2020, 2 463 RM patients with a Biotronik, Boston Scientific or Medtronic CIED (implantable defibrillator, pacemaker or implantable loop recorder), with a mean follow-up of 490 days [33–1386]. A total of 22 345 manufacturers' atrial burden related alerts were emitted while only 4 826 clinically significant events were detected by the algorithm: 1770 “1st recorded AT/AF episode”, 620 “Paroxysmal AF”, 252 “Increasing paroxysmal AF”, 1373 “Persistent AF”, and 811 “End of persistent AF”. These clinically significant events represent only 22% of the total number of atrial burden related alerts emitted by the manufacturers' platforms. Conclusion A new AF alert algorithm could have the potential to identify clinically significant AF status change in remotely monitored implanted patients while reducing the total number of alerts generated and thus the review burden for healthcare professionals. FUNDunding Acknowledgement Type of funding sources: None.

Workers with Cardiac AIMD Exposed to EMF: Methods and Case Studies for Risk Analysis in the Framework of the European Regulations

Workers with cardiac active implantable medical devices (AIMD), such as a pacemaker (PM) or an implantable defibrillator (ICD), are considered by the occupational health and safety regulation framework as a particularly sensitive risk group that must be protected against the dangers caused by the interference of electromagnetic field (EMF). In this paper, we first describe the general methodology that shall be followed for the risk assessment of employees with a cardiac AIMD exposed to EMF, according to the EU regulation, and in particular to the EN 50527-2-1:2016 and 50527-2-2:2018 standards. Then, three case studies related to specific EMF sources are presented, to better describe how the initial analysis of the risk assessment can be performed in practice, and to understand if a further specific risk assessment analysis is required or not.

Laminopathies: Should Wenckebach be a cause for concern? A case report

Background LMNA cardiomyopathy is a cause of dilated cardiomyopathy (DCM) characterised by aggressive heart failure, high risk of arrhythmias and sudden cardiac death. We present a case of a male presenting with a LMNA mutation with an aggressive DCM leading to sudden cardiac death (SCD). Case summary A 42-year-old male presented with the feeling of lethargy and intermittent dizziness. ECG demonstrated AV block in keeping with Mobitz type 1, at a rate of 40 b.p.m. and cardiac monitoring showed non-sustained VT. CMR imaging showed preserved left ventricular function (EF 59%) but features suggesting DCM. These included mild LV dilatation with an EDV of 213 mL and late enhancement showing a single mid myocardial focus of high signal over the distal RV insertion point inferiorly and a linear area of high signal over the basal septum. After discussion at cardiology multi-disciplinary meeting a pacemaker was implanted so that beta-blockers could be initiated to suppress the ventricular arrhythmias. A laminopathy was suspected and if this was confirmed from genetic testing the plan was to upgrade to an implantable defibrillator. Due to stability this was decided to be done in an outpatient setting. He unfortunately had an out of hospital VF arrest and died. Post-mortem showed subtle cardiomyopathy in keeping with a DCM. Genetic tests results were returned a few months later which confirmed a pathogenic variant in LMNA. Discussion Because of the complexity of LMNA-related cardiac disease, they should be managed and followed up in centres with special expertise in inherited cardiomyopathy.

Implantable Cardioverter‐Defibrillator Shocks During COVID‐19 Outbreak

Background COVID‐19 was temporally associated with an increase in out‐of‐hospital cardiac arrests, but the underlying mechanisms are unclear. We sought to determine if patients with implantable defibrillators residing in areas with high COVID‐19 activity experienced an increase in defibrillator shocks during the COVID‐19 outbreak. Methods and Results Using the Medtronic (Mounds View, MN) Carelink database from 2019 and 2020, we retrospectively determined the incidence of implantable defibrillator shock episodes among patients residing in New York City, New Orleans, LA, and Boston, MA. A total of 14 665 patients with a Medtronic implantable defibrillator (age, 66±13 years; and 72% men) were included in the analysis. Comparing analysis time periods coinciding with the COVID‐19 outbreak in 2020 with the same periods in 2019, we observed a larger mean rate of defibrillator shock episodes per 1000 patients in New York City (17.8 versus 11.7, respectively), New Orleans (26.4 versus 13.5, respectively), and Boston (30.9 versus 20.6, respectively) during the COVID‐19 surge. Age‐ and sex‐adjusted hurdle model showed that the Poisson distribution rate of defibrillator shocks for patients with ≥1 shock was 3.11 times larger (95% CI, 1.08–8.99; P =0.036) in New York City, 3.74 times larger (95% CI, 0.88–15.89; P =0.074) in New Orleans, and 1.97 times larger (95% CI, 0.69–5.61; P =0.202) in Boston in 2020 versus 2019. However, the binomial odds of any given patient having a shock episode was not different in 2020 versus 2019. Conclusions Defibrillator shock episodes increased during the higher COVID‐19 activity in New York City, New Orleans, and Boston. These observations may provide insights into COVID‐19–related increase in cardiac arrests.