Friedman, Paul A.

Abstract Recent guideline statements approve the performance of magnetic resonance imaging (MRI) in patients with non-conditional cardiac implantable electronic devices (CIEDs) under certain closely monitored conditions. Data from current registries may have lower power to discern changes that may occur in the CIED after the MRI. Objective We aimed to systematically review the literature to identify the adverse events and significance of changes in device function associated with performing MRI in patients with CIEDs Methods A comprehensive literature search of the databases was performed between 1980- 2017. Two independent reviewers selected studies and extracted data. A random-effects model was used for meta-analysis. Results A total of 7,422 patients underwent 8,865 MRI studies. No death occurred post MRI. Clinical adverse events were extremely rare (mostly less than 1%) and are summarized in Table 1. No significant changes in the pooled mean effect size estimate was noted for the changes in the lead parameters (pacing threshold, sensing and impedance) Binary outcomes post magnetic resonance imaging in patients with non-conditional cardiac implantable electronic devices Outcome Sample size Number of patients Rate SE LL of CI UL of CI Death 7401 0 0 0 0 0 Atrial arrhythmia 7173 10 0.001 0.0004 0.0007 0.0024 Ventricular arrhythmia 7371 9 0.0012 0.0004 0.0006 0.0022 Oversensing 4981 17 0.0034 0.0008 0.0020 0.0053 Inhibition of pacing 7371 6 0.0008 0.0003 0.0003 0.0016 Lead Failure/Generator Failure 7475/7475 2/8 0.0002/0.0011 0.0001/0.0004 0.0001/0.0005 0.0009/0.002 Power on Reset 1388 105 0.0131 0.0014 0.0107 0.0161 Did not complete scan 6851 13 0.0019 0.0005 0.0011 0.0031 Chest pain 7080 11 0.0021 0.0004 0.0008 0.0027. Lead threshold rise (>0.5v/>50%-A/V) 5076/6246 12/16 0.0024/0.0026 0.0007/0.0006 0.0013/0.0015 0.0040/0.0041 Change in Battery voltage >0.04V 7132 42 0.0061 0.0009 0.0043 0.0079 Sensing decrease >50%-A/V 5087/5834 17/9 0.0033/0.0015 0.0008/0.0005 0.0020/0.0008 0.0052/0.0028 Impedance changes >50ohms/>50% 5810 22 0.0038 0.0008 0.0024 0.0057 Rise in cardiac enzymes 1703 26 0.0152 0.0030 0.0102 0.0219 A, atrial; V, ventricular; SE, standard Error; LL, lower limit; UL, upper limit; CI, Confidence intervals. Conclusions MRI in patients with non-conditional CIEDs can be performed with high degree of safety and low rate of clinical events when performed under standardized protocols Acknowledgement/Funding None

AbstractBackgroundInappropriate sinus tachycardia (IST) remains a clinical challenge because patients often are highly symptomatic and not responsive to medical therapy.ObjectiveTo study the safety and efficacy of stellate ganglion (SG) block and cardiac sympathetic denervation (CSD) in patients with IST.MethodsTwelve consecutive patients who had drug‐refractory IST (10 women) were studied. According to a prospectively initiated protocol, five patients underwent an electrophysiologic study before and after SG block (electrophysiology study group). The subsequent seven patients had ambulatory Holter monitoring before and after SG block (ambulatory group). All patients underwent SG block on the right side first, and then on the left side. Selected patients who had heart rate reduction ≥15 beats per minute (bpm) were recommended to consider CSD.ResultsThe mean (SD) baseline heart rate (HR) was 106 (21) bpm. The HR significantly decreased to 93 (20) bpm (P = .02) at 10 minutes after right SG block and remained significantly slower at 97(19) bpm at 60 minutes. Left SG block reduced HR from 99 (21) to 87(16) bpm (P = .02) at 60 minutes. SG block had no significant effect on blood pressure or HR response to isoproterenol or exercise (all P > .05). Five patients underwent right (n = 4) or bilateral (n = 1) CSD. The clinical outcomes were heterogeneous: one patient had complete and two had partial symptomatic relief, and two did not have improvement.ConclusionSG blockade modestly reduces resting HR but has no significant effect on HR during exercise. Permanent CSD may have a modest role in alleviating symptoms in selected patients with IST.

AbstractIntroductionMyocardial infarction (MI) is associated with an increase in subsequent heart failure (HF), recurrent ischemic events, sudden cardiac arrest, and ventricular arrhythmias (SCA‐VA). The primary objective of the study to determine the role of intercurrent HF and ischemic events on the development of SCA‐VA following first type I MI.Methods and resultsA retrospective cohort study of patients experiencing first type 1 MI in Olmsted County, Minnesota (2002‐2012) was conducted by identifying patients using the medical records linkage system (Rochester epidemiology project). Patients aged ≥18 years were followed from the time of MI till death or 31 July, 2017. Intercurrent HF and ischemic events were the primary exposures following MI and their association with outcome SCA‐VA was assessed. Eight hundred and sixty‐seven patients (mean age was 63 ± 14.5 years; 69% male; 49.8% ST‐elevation myocardial infarction) who had their first type I MI during the study period were included. Majority of acute MI patients were revascularized using percutaneous coronary intervention and bypass surgery (628 [72.43%] and 87 [10.03%] respectively). During a mean follow‐up of 7.69 ± 4.17 years, HF, recurrent ischemic events and SCA‐VA occurred in 155 (17.9%), 245 (28.3%), and 40 (4.61%) patients respectively. Low ejection fraction (adjusted hazard ratio [HR] 0.95; 95% confidence interval [CI], 0.93‐0.98; P < .001), intercurrent HF (adjusted HR 3.11; 95% CI, 1.39‐6.95; P = .006) and recurrent ischemic events (adjusted HR 3.47; 95% CI, 1.68‐7.18; P < .001) were associated with subsequent SCA‐VA.ConclusionSCA‐VA occurred in a small proportion of patients after MI and is associated with intercurrent HF and recurrent ischemic events.

Background: Percutaneous stellate ganglion blockade (SGB) has been used for drug-refractory electrical storm due to ventricular arrhythmia (VA); however, the effects and long-term outcomes have not been well studied. Methods: This study included 30 consecutive patients who had drug-refractory electrical storm and underwent percutaneous SGB between October 1, 2013, and March 31, 2018. Bupivacaine, alone or combined with lidocaine, was injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion (n=15) or both stellate ganglia (n=15). Data were collected for patient clinical characteristics, immediate and long-term outcomes, and procedure-related complications. Results: Clinical characteristics included age, 58±14 years; men, 73.3%; and left ventricular ejection fraction, 34±16%. At 24 hours, 60% of patients were free of VA. Patients whose VA was controlled had a lower hospital mortality rate than patients whose VA continued (5.6% versus 50.0%; P =0.009). Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in VA episodes from 26±41 to 2±4 in the 72 hours after SGB ( P <0.001). Patients who died during the same hospitalization (n=7) were more likely to have ischemic cardiomyopathy (100% versus 43.5%; P =0.03) and recurrent VA within 24 hours (85.7% versus 26.1%; P =0.009). There were no procedure-related major complications. Conclusions: SGB effectively attenuated electrical storm in more than half of patients without procedure-related complications. Percutaneous SGB may be considered for stabilizing ventricular rhythm in patients for whom other therapies have failed.

Background: Sex and age have long been known to affect the ECG. Several biologic variables and anatomic factors may contribute to sex and age-related differences on the ECG. We hypothesized that a convolutional neural network (CNN) could be trained through a process called deep learning to predict a person’s age and self-reported sex using only 12-lead ECG signals. We further hypothesized that discrepancies between CNN-predicted age and chronological age may serve as a physiological measure of health. Methods: We trained CNNs using 10-second samples of 12-lead ECG signals from 499 727 patients to predict sex and age. The networks were tested on a separate cohort of 275 056 patients. Subsequently, 100 randomly selected patients with multiple ECGs over the course of decades were identified to assess within-individual accuracy of CNN age estimation. Results: Of 275 056 patients tested, 52% were males and mean age was 58.6±16.2 years. For sex classification, the model obtained 90.4% classification accuracy with an area under the curve of 0.97 in the independent test data. Age was estimated as a continuous variable with an average error of 6.9±5.6 years (R-squared =0.7). Among 100 patients with multiple ECGs over the course of at least 2 decades of life, most patients (51%) had an average error between real age and CNN-predicted age of <7 years. Major factors seen among patients with a CNN-predicted age that exceeded chronologic age by >7 years included: low ejection fraction, hypertension, and coronary disease ( P <0.01). In the 27% of patients where correlation was >0.8 between CNN-predicted and chronologic age, no incident events occurred over follow-up (33±12 years). Conclusions: Applying artificial intelligence to the ECG allows prediction of patient sex and estimation of age. The ability of an artificial intelligence algorithm to determine physiological age, with further validation, may serve as a measure of overall health.

AbstractBackgroundRecipients of implantable cardioverter defibrillator (ICD) generator replacement with multiple medical comorbidities may be at higher risk of adverse outcomes that attenuate the benefit of ICD replacement. The aim of this investigation was to study the association between the Charlson comorbidity index (CCI) and outcomes after ICD generator replacement.MethodsAll patients undergoing first ICD generator replacement at Mayo Clinic, Rochester and Beth Israel Deaconess Medical Center, Boston between 2001 and 2011 were identified. Outcomes included: (a) all‐cause mortality, (b) appropriate ICD therapy, and (c) death prior to appropriate therapy. Multivariable Cox regression analysis was performed to assess association between CCI and outcomes.ResultsWe identified 1421 patients with mean age of 69.6 ± 12.1 years, 81% male and median (range) CCI of 3 (0‐18). During a mean follow‐up of 3.9 ± 3 years, 52% of patients died, 30.6% experienced an appropriate therapy, and 23.6% died without experiencing an appropriate therapy. In multivariable analysis, higher CCI score was associated with increased all‐cause mortality (Hazard ratio, HR 1.10 [1.06‐1.13] per 1 point increase in CCI, P < .001), death without prior appropriate therapy (HR 1.11 [1.07‐1.15], P < .0001), but not associated with appropriate therapy (HR 1.01 [0.97‐1.05], P = .53). Patients with CCI ≥5 had an annual risk of death of 12.2% compared to 8.7% annual rate of appropriate therapy.ConclusionsCCI is predictive of mortality following ICD generator replacement. The benefit of ICD replacement in patients with CCI score ≥5 should be investigated in prospective studies.

AbstractBackgroundThere are few data regarding the outcome of a combined cryo‐ and radiofrequency (RF)‐catheter ablation of various types of supraventricular tachycardias (SVTs) originating from near the normal conduction system.METHODSWe analyzed all patients undergoing combined cryo‐ and RF‐ catheter ablation at Mayo Clinic, Rochester, MN as part of the ablation of SVTs with potential risks of injury to the normal conduction system. This study aimed to assess the outcome of a combined cryo‐ and RF‐catheter ablation of various types of SVTs.RESULTSThe study population consisted of 54 patients (38 ± 17 years, 32 men). A combined cryo‐ and RF‐catheter ablation was attempted for septal accessary pathways (APs) in 26, atrioventricular nodal reentrant tachycardia (AVNRT) in 14, atrial tachycardia (AT) in 7, and junctional ectopic tachycardia in 7 patients. Forty‐one patients (76%) were successfully ablated with cryoablation, and RF ablation after an unsuccessful cryoablation ablated the SVTs successfully at the same location in 6 patients (11%). Complication occurred in 1 patient (deep vein thrombosis). The cumulative freedom from SVT rate at 30 days after the procedure was 78% and there was no significant difference in the recurrence rate among the SVTs.CONCLUSIONA combined cryo‐ and RF‐catheter ablation is clinically effective in patients undergoing SVT ablation with the potential risk of injury to the normal conduction system.

AbstractBackgroundThe Micra clinical trials have enrolled more than 2500 patients without any reported device‐related infections that required removal during follow‐up. Leadless pacemakers might be more resistant to bacterial seeding due to smaller surface area and a greater tendency for encapsulation.ObjectiveTo analyze the incidence and outcomes of serious infectious events (SIEs: bacteremia or endocarditis) that developed during follow‐up in patients with history of Micra leadless pacemaker implantation.MethodsSIE and outcomes were characterized based upon adverse event reports. Among 720 patients implanted with Micra in the investigational device exemption trial, we identified 16 patients who had documented 21 SIEs during follow‐up.ResultsAmong patients with SIEs, mean age was 71.9 ± 11.7 years. SIEs occurred at a mean 4.8 ± 4.5 months after implant and patients were followed for 13.1 ± 9.1 months after documentation of SIE. All events were adjudicated as unrelated to the Micra device or procedure. Bacteremia was documented to be related to a gram‐positive organism in 13 events (seven Staphylococcus, three Streptococcus, two Enterococcus, and one uncharacterized gram‐positive bacteria), and gram‐negative organisms in three events. In five events, the type of organism was not characterized (two patients with endocarditis). No persistent cases of bacteremia after antibiotic cessation were seen over the duration of follow‐upConclusionIn this small series of Micra patients who developed SIEs postimplant, the occurrence of bacteremia and/or endocarditis did not appear to lead to persistent bacteremia off antibiotics; most events resolved with antibiotic treatment.

AbstractIntroductionAutonomic modulation has been used as a therapy to control recurrent ventricular arrhythmia (VA). This study was to explore stellate ganglion block (SGB) effect on cardiac electrophysiologic properties and evaluate the long‐term outcome of cardiac sympathetic denervation (CSD) for patients with recurrent VA and structural heart disease (SHD).Materials and MethodsPatients who had recurrent VA due to SHD were enrolled prospectively. Electrophysiologic study and ventricular tachycardia (VT) induction were performed before and after left and right SGB. VA burden and long‐term outcomes were assessed for a separate patient group who underwent left or bilateral CSD for drug‐refractory VA due to SHD.ResultsElectrophysiologic study of nine patients showed that baseline mean (SD) corrected sinus node recovery time (cSNRT) increased from 320.4 (73.3) ms to 402.9 (114.2) ms after left and 482.4 (95.7) ms after bilateral SGB (P = .03). SGB did not significantly change P‐R, QRS, and Q‐T intervals and ventricular effective refractory period, nor did the inducibility of VA. Nineteen patients underwent left (n = 14) or bilateral (n = 5) CSD. CSD reduced VA burden and appropriate ICD therapies from a median (interquartile range) of 2.5 (0.4‐11.6) episodes weekly to 0.1 (0.0‐2.4) episodes weekly at 6‐month follow‐up (P = .002). Three‐year freedom from orthotopic heart transplant (OHT) and death was 52.6%. New York Heart Association functional class III/IV and VT rate less than 160 beats per minute were predictors of recurrent VA, OHT, and death.ConclusionSGB increased cSNRT without changing heart rate. CSD was more beneficial for patients with mild‐to‐moderate heart failure and faster VA.

AbstractIntroductionEmerging medical technology has allowed for monitoring of heart rhythm abnormalities using smartphone compatible devices. The safety and utility of such devices have not been established in patients with cardiac implantable electronic devices (CIEDs). We sought to assess the safety and compatibility of the Food and Drug Administration‐approved AliveCor Kardia device in patients with CIEDs.Methods and ResultsWe prospectively recruited patients with CIED for a Kardia recording during their routine device interrogation. A recording was obtained in paced and nonpaced states. Adverse clinical events were noted at the time of recording. Electrograms (EGMs) from the cardiac device were obtained at the time of recording to assess for any electromagnetic interference (EMI) introduced by Kardia. Recordings were analyzed for quality and given a score of 3 (interpretable rhythm, no noise), 2 (interpretable rhythm, significant noise) or 1 (uninterpretable). A total of 251 patients were recruited (59% with a pacemaker and 41% with ICD). There were no adverse clinical events noted at the time of recording and no changes to CIED settings. Review of all EGMs revealed no EMI introduced by Kardia. Recordings were correctly interpreted in 90% of paced recordings (183 had a score of 3, 43 of 2, and 25 of 1) and 94.7% of nonpaced recordings (147 of 3, 15 of 2, and 9 of 1).ConclusionThe AliveCor Kardia device has an excellent safety profile when used in conjunction with most CIEDs. The quality of recordings was preserved in this population. The device, therefore, can be considered for heart rhythm monitoring in patients with CIEDs.