Citations

Background : Lipid lowering therapy reduces mortality in patients with both ischemic and nonischemic cardiomyopathies and recently has been shown to decrease ICD shocks. Radiofrequency ablation (RFA) of recurrent VT in patients with an ICD also reduces shocks following intervention. It is unclear if statin therapy after VT RFA will further impact ICD shock rates. Methods : All patients from 1993–2005 who underwent a RFA procedure for recurrent VT at the Mayo Clinic with an ICD were included. Patient records were extracted for medical and procedural details and all ICD interrogations were reviewed for VT recurrence and therapies. Results: 63 patients (age 62±15 years) were followed over 3.9±3.6 years. Comorbid diseases included: coronary artery disease 37(58%, 34 prior myocardial infarction), ARVD/C 6(10%), nonischemic dilated cardiomyopathy 7(11%), moderate-severe valve disease 14(22%), hypertension 34(54%), and hyperlipidemia 35(56%). Ejection fraction was <0.35 in 34(56%). VT was induced in all patients (LV 55 (LVOT 1), RV 8 (RVOT 3) with multiple inducible VTs in 21(33%). VT was noninducible after RFA in 39(62%) patients. Dismissal medications included: statins 19(30%), beta blockers 40(66%), ACE/ARB 37(61%), diuretics 34(55%), and digoxin 23(37%). 5-year overall survival was 63%(95% CI 55–71). Age, diabetes, and renal insufficiency were associated with increased post ablation mortality, with no medication improving survival. 5-year survival free of ICD shocks was 31%(95% CI 24–38). Only statin therapy at discharge was associated with a decreased risk of ICD shocks [5(26%) versus 26(59%), p=0.020]. 7 additional patients received statins during follow-up, but not at discharge, of these 5(71%) had shocks. Conclusion : Statin use at discharge in patients with an ICD undergoing RFA for refractory VT significantly reduced recurrent ventricular arrhythmias and ICD shocks. Although the mechanism underlying the effects of statins on arrhythmic recurrence early after RFA requires further study, these data support aggressive therapy of the underlying substrate responsible for the VT.

Background: Long QT syndrome (LQTS) is a potentially lethal yet highly treatable channelopathy underscored by marked heterogeneity that necessitates evidence-based and individualized therapeutic approaches. One such therapy is the implantable cardioverter defibrillator (ICD). Here, we sought to determine the percentage of patients (pts) with LQTS that received an ICD in our LQTS clinic and its short term outcomes. Methods: An IRB-approved, retrospective analysis of the electronic medical records of 167 LQT1, 113 LQT2, and 29 LQT3 pts evaluated in our LQTS Clinic with subset analysis of those implanted with an ICD in our institution from January 2000 to June 2007. Results: Forty-eight pts (15% of total, 33 females, 14 LQT1, 20 LQT2, and 14 LQT3) received an ICD. The average age at implant was 30 ± 12 years (range 8 – 52 years). Nearly two-thirds received an ICD as primary prevention. The QTc exceeded 500 ms in 18 (37.5%). With an average follow-up of 42 ± 32 months, 9 (19%) have had an appropriate, VF-terminating therapy including 3 with LQT1 and 6 with LQT2. Notably, 5 of the 6 LQT2 females have already received an appropriate ICD therapy whereas none of the LQT3 pts have received one. Secondary prevention indications (p = 0.006), LQT2 genotype (p = 0.03), QTc > 500 ms (p = 0.001), and surprisingly a negative family history (p = 0.0005) predicted those ICD pts most likely to receive an appropriate therapy. Importantly, none of the non-ICD treated pts (> 250) have died a LQT-related death during the same follow-up. Conversely, 9 pts have experienced an inappropriate shock including 6 with LQT3 and males were more likely to receive inappropriate therapies (p = 0.002). Conclusions: The majority of pts with LQTS can be treated effectively without an ICD. In this study, potentially life-saving therapies have been rendered so far at a 5– 6%/year rate. Inappropriate shocks occurred with similar frequency. Secondary prevention, genotype, and QTc predicted those ICD recipients most likely to receive appropriate therapy. Although LQT3 status is commonly associated with an ICD recommendation, so far none of the LQT3 positive ICD recipients have needed their device. Instead, the greatest “save” rate has occurred among the LQT2 positive females deemed at high risk.

Determining whether retrograde ventriculoatrial (VA) conduction is through the AV node (AVN) or an accessory pathway (AP) is critical for successful ablation of supraventricular tachycardia (SVT). With introduction of ventricular extrastimuli (VEST), retrograde right bundle branch block (retro RBBB) may occur and result in abrupt VH interval prolongation. We hypothesized when retrograde conduction is via an AP, VA interval change is less than VH interval change, whereas with retrograde AVN conduction, VA interval change is equal to or greater than VH interval change. We retrospectively reviewed the electrophysiology (EP) studies of patients undergoing ablation for AVNRT (n=55) or AVRT (n=50). The intracardiac electrograms were reviewed for induction of retro RBBB and change in VH and VA intervals during VEST. Parahisian pacing, decremental pacing, arrhythmia diagnosis and ablation outcomes were reviewed. All results were found to be reproducible between two independent observers with inter and intra observer reliability scores of 1.00 for identification of retro RBBB and greater than 0.85 for measurement of VH and VA intervals. Of 105 patients, 84 (80%) had evidence of induced retro RBBB during VEST. The average VH interval increase with induction of retro RBBB was 53.7 ms for patients with retrograde AP conduction and 54.4 ms for patients with AVN conduction (p=ns). The average VA interval increase with induction of retro RBBB was 13.6 ms with AP conduction and 70.1 ms with AVN conduction (P < 0.001). All patients with a greater VH than VA interval change had a final diagnosis of AVRT and those with a VH change less than VA change had AVNRT, yielding sensitivity and specificity of 100%. Using a cutoff of 50 ms for change in VA interval with onset of retro RBBB to diagnose AVNRT accurately identified AVNRT in 100% and AVRT in 95%. Induction of retro RBBB during VEST is common during EP studies for SVT. The relative change in the VH and VA intervals during retro RBBB accurately differentiates retrograde AVN from retrograde AP conduction with strong predictive accuracy. The use of retro RBBB based intervals is a useful technique facilitating the diagnosis of SVT in the EP laboratory, even in the absence of inducible tachycardia.

Introduction: Left atrial appendage (LAA) flow depends largely on left ventricular compliance and may play a role in mediating the regulation of left atrial volume-pressure relationships. Hypothesis: We hypothesize that LAA emptying flow velocity (LAAEV) is a predictive factor of long-term outcomes (e.g. recurrent AF, stroke, and survival) after cardioversion for non-valvular AF. Method: We identified 3,251 consecutive patients with non-valvular AF who underwent successful TEE-guided electrical cardioversion (ECV) at our institution between May 2000 and March 2012. Successful ECV was defined as sinus rhythm at time of discharge from the cardioversion unit. Patients were monitored following their ECV procedure for first documentation of recurrent AF, stroke or death. Multivariate Cox proportional hazards models were used to identify independent predictors of long-term outcomes. Patients with >= moderate valvular regurgitation or stenosis were excluded. Results: Among the 3,251 patients who were successfully cardioverted to sinus rhythm, the mean (±SD) LAAEV was 38.43±23 cm/s and the median was 33 cm/s, (interquartile range [IQR], 20-50). Patients with LAAEV <=33 cm/s had higher CHA 2 DS 2 -VASc score (2.6±1.2 vs. 1.9±1.3, P =.009), larger LAVI (52.0±20.9 cc/m 2 vs. 43.3±13.6 cc/m 2 , P <.001) than those with LAAEV >33 cm/s. Pre or post-procedure antiarrhythmic drug use was similar between the two groups. During 1-year follow-up, patients with LAAEV <=33 cm/s had significantly higher rate of AF recurrence than those with LAAEV >33 cm/s (55% vs 45%, P <.001). Likewise, during a mean follow-up of 4.9±3.6 years, similar patterns in 5-year rates were observed for first recurrence of AF (81% vs 73%, P <.001), stroke (7% vs 4%, P =.003) and mortality (31% vs 23%, P <.001) for LAAEV <=33 vs > 33cm/s, respectively. Stepwise multivariate Cox regression analysis revealed that LAAEV <=33 cm/s, age, CHA 2 DS 2 -VASc score were independent predictors of AF recurrence, stroke and mortality. Conclusions: LAA emptying flow velocity is an effective and convenient method for risk stratification of patients undergoing cardioversion for AF. Our data showed that patients with reduced LAAEV have an increased risk for AF recurrence, stroke and death following electrical cardioversion.

Background: Data regarding ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation following MVS is limited.) CA can be challenging given perivalvular substrate in the setting of mitral annuloplasty or prosthetic valves. Objective: To investigate the characteristics, safety, and outcomes of radiofrequency catheter ablation (CA) in patients with prior mitral valve surgery (MVS) and ventricular arrhythmias (VA). Methods: We identified consecutive patients with prior MVS who underwent CA for VT or PVC between January 2013- December 2018. We investigated the mechanism of arrhythmia, ablation approach, peri-operative complications, and outcomes. Results: In our cohort of 31 patients (77% men, mean age 62.3±10.8 years, left ventricular ejection fraction 39.2±13.9%) with prior MVS underwent CA (16 VT; 15 PVC). Access to the left ventricle was via transseptal approach in 17 patients, and a retrograde aortic approach was used in 13 patients. A combined transseptal and retrograde aortic approach was used in one patient, and a percutaneous epicardial approach was combined with trans-septal approach in 1patient. Heterogenous scar regions were present in 94% of VT patients and scar-related reentry was the dominant mechanism of VT. Clinical VA substrates involved the peri-mitral area in 6 patients with VT and 5 patients with PVC ablation. No procedure-related complications were reported. The overall recurrence-free rate at 1-year was 72.2%; 67% in the VT group and 78% in the PVC group. No arrhythmia-related death was documented on long-term follow-up. Conclusion: CA of VAs can be performed safely and effectively in patients with MVS

Introduction: An artificial intelligence (AI) algorithm applied to electrocardiography (ECG) during normal sinus rhythm (NSR) has been shown to predict concomitant atrial fibrillation (AF). We sought to characterize the value of AI-ECG as a predictor of future AF and assess its performance compared to other clinical prediction scores in a population-based sample. Methods: We calculated the AI-ECG probability during NSR in patients who enrolled in the population-based Mayo Clinic Study of Aging with at least one ECG in NSR within two years prior and no history of AF at the time of the baseline study visit. The cumulative incidence of AF was estimated for strata defined by AI-ECG probability and CHARGE-AF score. Cox proportional hazards were fit to assess the independent prognostic value and interaction of AI-ECG probability and CHARGE-AF score. Concordance (c) statistics were calculated for AI-ECG probability, CHARGE-AF score and combined AI-ECG and CHARGE-AF score. Results: A total of 1,936 patients with a median age 75.8 (quartile range [QR] 70.4, 81.8) years, median CHARGE-AF score 14.0 (QR 13.2, 14.7) and median CHADS2VASC score 3 (QR 2, 4) were included in the analysis. The cumulative incidence of AF increased in a stepwise fashion across quartiles of AI-ECG probability and CHARGE-AF score (Figure 1). When compared in the same model, both AI-ECG probability (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.51-2.04) and CHARGE-AF score (HR 1.90, 95% CI 1.58-2.28) independently predicted AF without significant interaction (p=0.54). C statistics were 0.69 (95% CI 0.66-0.72) for AI-ECG probability, 0.69 (95% CI 0.66-0.71) for CHARGE-AF and 0.72 (95% CI 0.69-0.75) for combined AI-ECG and CHARGE-AF score. Conclusions: In the Mayo Clinic Study of Aging, both the AI-ECG probability and CHARGE-AF score independently predicted time to AF. The AI-ECG may offer a means to assess risk with a single test without requiring manual or automated clinical data abstraction.

Background: Left atrial appendage occlusion (LAAO) devices have successfully provided an alternative therapeutic option in patients with atrial fibrillation and high bleeding risk. However, patients with thrombocytopenia (TP) were underrepresented in the milestone trials, and the optimal strategy of postprocedural antithrombotic therapy in this group of patients remains unclear. Methods: Patients were identified from the National Cardiac Database Registry - LAAO database at all three Mayo Clinic sites in the period from 1/2016-10/2019. Patients were further divided into TP (platelet &lt; 150 x 10^9/L) and control (platelet &gt; 150 x 10^9 /L) groups for clinical outcome analysis. Outcome endpoints include composite of bleeding (GI bleeding, hemorrhagic stroke, and other non-intracranial hemorrhage) and composite thrombotic events (device thrombus, ischemic stroke, TIA and undetermined stroke). Results: A total of 249 consecutive patients were included in the final analysis. The mean age was 76.7 ± 7.2 years, and 169 (67.9%) were male; 242 (97.2%) were white. The mean CHA2DS2-VASc score was 5.3 ±1.5, and the HAS-BLED score was 3.0 ± 1.1. TP at baseline was present in 74 (29.7%) patients. The median follow-up time was 6.8 months. The use of post-procedural antithrombotic regimens was similar between the two groups (Table 1). When comparing the TP group to control, there was no significant difference in composite bleeding events (10.8% vs. 8.0%, P = 0.069) and thrombotic events (2.7% vs. 2.3%, P= 0.170). Conclusions: The presence of baseline TP does not significantly increase post-procedural bleeding risk in atrial fibrillation/atrial flutter patients who underwent an LAAO occlusion procedure with the Watchman device (Boston Scientific). This group of patients can be treated with the same antithrombotic regimen as patients with normal platelet levels. Future studies are still warranted to determine the optimal antithrombotic regimen.

Background The temporal incidence of high‐grade atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) is uncertain. As a result, periprocedural monitoring and pacing strategies remain controversial. This study aimed to describe the temporal incidence of initial episode of HAVB stratified by pre‐ and post‐TAVR conduction and identify predictors of delayed events. Methods and Results Consecutive patients undergoing TAVR at a single center between February 2012 and June 2019 were retrospectively assessed for HAVB within 30 days. Patients with prior aortic valve replacement, permanent pacemaker (PPM), or conversion to surgical replacement were excluded. Multivariable logistic regression was performed to assess predictors of delayed HAVB (initial event >24 hours post‐TAVR). A total of 953 patients were included in this study. HAVB occurred in 153 (16.1%). After exclusion of those with prophylactic PPM placed post‐TAVR, the incidence of delayed HAVB was 33/882 (3.7%). Variables independently associated with delayed HAVB included baseline first‐degree atrioventricular block or right bundle‐branch block, self‐expanding valve, and new left bundle‐branch block. Forty patients had intraprocedural transient HAVB, including 16 who developed HAVB recurrence and 6 who had PPM implantation without recurrence. PPM was placed for HAVB in 130 (13.6%) (self‐expanding valve, 23.7% versus balloon‐expandable valve, 11.9%; P <0.001). Eight (0.8%) patients died by 30 days, including 1 unexplained without PPM present. Conclusions Delayed HAVB occurs with higher frequency in patients with baseline first‐degree atrioventricular block or right bundle‐branch block, new left bundle‐branch block, and self‐expanding valve. These findings provide insight into optimal monitoring and pacing strategies based on periprocedural ECG findings.

Abstract Background We have demonstrated that a neural network is able to predict a person’s age from the electrocardiogram (ECG) [artificial intelligence (AI) ECG age]. However, some discrepancies were observed between ECG-derived and chronological ages. We assessed whether the difference between AI ECG and chronological age (Age-Gap) represents biological ageing and predicts long-term outcomes. Methods and results We previously developed a convolutional neural network to predict chronological age from ECGs. In this study, we used the network to analyse standard digital 12-lead ECGs in a cohort of 25 144 subjects ≥30 years who had primary care outpatient visits from 1997 to 2003. Subjects with coronary artery disease, stroke, and atrial fibrillation were excluded. We tested whether Age-Gap was correlated with total and cardiovascular mortality. Of 25 144 subjects tested (54% females, 95% Caucasian) followed for 12.4 ± 5.3 years, the mean chronological age was 53.7 ± 11.6 years and ECG-derived age was 54.6 ± 11 years (R2 = 0.79, P &lt; 0.0001). The mean Age-Gap was small at 0.88 ± 7.4 years. Compared to those whose ECG-derived age was within 1 standard deviation (SD) of their chronological age, patients with Age-Gap ≥1 SD had higher all-cause and cardiovascular disease (CVD) mortality. Conversely, subjects whose Age-Gap was ≤1 SD had lower all-cause and CVD mortality. Results were unchanged after adjusting for CVD risk factors and other survival influencing factors. Conclusion The difference between AI ECG and chronological age is an independent predictor of all-cause and cardiovascular mortality. Discrepancies between these possibly reflect disease independent biological ageing.