Sustained Ventricular Fibrillation Research Articles

Predictors of ventricular tachyarrhythmia in patients with a wearable cardioverter defibrillator: an international multicenter registry.

Wearable cardioverter defibrillator (WCD) can protect patients from sudden cardiac death due to ventricular tachyarrhythmias and serve as a bridge to decision of definite defibrillator implantation. The aim of this analysis from an international, multicenter WCD registry was to identify predictors of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) in this population. One thousand six hundred seventy-five patients with WCD were included in a multicenter registry from 9 European centers, with a median follow-up of 440days (IQR 120-893). The primary study end point was the occurrence of sustained VT/VF. Sustained VT was detected by WCD in 5.4% and VF in 0.9% of all patients. Of the 30.3% of patients receiving ICD implantation during follow-up, sustained VT was recorded in 9.3% and VF in 2.6%. Non-ischemic cardiomyopathy (HR 0.5, p < 0.001), and medication with angiotensin-converting enzyme inhibitors (HR 0.7, p = 0.027) and aldosterone antagonists (HR 0.7, p = 0.005) were associated with a significantly lower risk of VT/VF. Patients who received WCD due to a transient increased risk of sudden cardiac death have a comparatively lower risk of VT/VF in the presence of non-ischemic cardiomyopathy. Of note, optimal medical treatment for heart failure not only results in an improvement in left ventricular ejection fraction but also in a reduction in the risk for VT/VF.

Arrhythmic mitral valve prolapse with versus without prior mitral valve repair: clinical profiles, electrophysiological substrates, and long-term clinical outcomes

Abstract Background Arrhythmic mitral valve prolapse (AMVP) is characterized by an arrhythmogenic left ventricular substrate, with high prevalence of myocardial scar. Whether patients with prior mitral valve repair for mitral valve prolapse (MVP) and new-onset complex ventricular arrhythmias (VAs) after cardiac surgery have different electroanatomical substrate and arrhythmic outcomes compared with AMVP patients without prior mitral valve surgery is currently unknown. Purpose We sought to compare the electroanatomical substrate and long-term clinical outcomes of patients with new-onset complex VAs after mitral valve surgery to AMVP patients without prior surgery. Methods We conducted a multicenter, prospective, observational study, enrolling MVP patients with prior mitral valve repair and new-onset complex VAs (&amp;gt;1000 premature ventricular contractions [PVCs]/day, nonsustained ventricular tachycardia [NSVT], and sustained VT) after cardiac surgery (group A,n=9), and patients with MVP, complex VAs and no prior surgery (group B,n=20). Each patient underwent a comprehensive diagnostic workup, including left ventricular electroanatomical mapping. Clinical-imaging data, as well as the location and segmental extension of both low-voltage areas and late potentials were assessed and compared between the two groups. The primary outcome was the occurrence of sustained VT or ventricular fibrillation(VF) during follow-up. Results In group A, complex VAs were first diagnosed after a median of 30(8-56) months following mitral valve repair. The characteristics of patients from the two study groups are presented in the Table. Patients from group A were older, sustained VT was nonsignificantly more common at baseline, the PVC count nonsignificantly higher, and LVEF nonsignificantly lower. Mitral annular disjunction was never observed in group A, while it was found in 7 patients from group B (p=0.066). At LV electroanatomical voltage mapping, bipolar and unipolar low-voltage areas (LVAs) were equally common in the two groups overall, and typically involved basal perimitral regions. However, patients from group B had concomitant bipolar and unipolar LVAs 50% of times, with larger unipolar LVAs, while patients from group A mostly showed isolated bipolar LVAs. Over a median follow-up of 15 (12-41) months, patients from group A (n=3, 33%) had slightly higher incidence of sustained VT or VF (HR: 1.91; 95% CI, 1.06-42.65; log-rank p=0.02, Figure) than patients from group B (n=2, 10%). Conclusion Compared to patients with AMVP and no prior cardiac surgery, patients with new-onset complex VAs after mitral valve repair for MVP have a slightly different clinical profile and electroanatomical substrate, characterized by predominant bipolar LVAs in the perimitral region. The long-term risk of major ventricular arrhythmias appears slightly higher in MVP patients with prior mitral valve surgery, mandating at least an equally careful risk assessment in both groups.

Clinical impact of ICD implantation in octogenarians: a longitudinal cohort study

Abstract Background The implantation of defibrillators (ICDs) in patients over 80 years old is becoming increasingly common; however, evidence-based data regarding the actual clinical benefit in this population remain limited and contradictory. While age seems not to affect mortality and arrhythmia risk in octogenarians undergoing secondary prevention, the mortality reduction benefit given by ICD implantation for primary prevention appears to decrease with advancing age, likely due to the high number of non-arrhythmic deaths. Purpose This study aims to assess the long-term incidence of ventricular arrhythmias and mortality in a real-world cohort of octogenarian patients undergoing ICD implants. Methods This was an observational, retrospective, longitudinal cohort study. Demographic, clinical, and radiological data were collected for all patients undergoing ICD implantation between 2014 and 2021. Deaths from all causes and significant arrhythmic events (sustained ventricular tachycardias and ventricular fibrillation) detected during routine device controls and remote monitoring were recorded. Then was performed an univariate Kaplan-Meier analysis, stratifying the population by age in relation to the two study endpoints: ventricular arrhythmias and all-cause mortality. Results Out of a total of 700 patients, 512 underwent ICD implantation before the age of 80 (mean age at implantation 64±12), while 188 underwent ICD implantation after the age of 80 (mean age at implantation 82±3.2). No significant differences were found between these two groups in terms of gender (82% vs. 83% male; p 0.12), indication for implantation (74% vs. 75% primary prevention; p 0.79), and the presence of late gadolinium enhancement (LGE) on cardiac MRI (68% vs. 77%; p 0.14). Octogenarians were more frequently affected by ischemic heart disease (54% vs. 65%; p 0.01) and were more frequently treated with Amiodarone (17% vs. 24%; p 0.02). At the end of the average 8-year follow-up, octogenarians had significantly higher all-cause mortality than younger patients (HR=2.35 [1.88-3.16]; p&amp;lt;0.05), with survival curves diverging from 3 years after implantation. However, ventricular arrhythmic events were significantly reduced in octogenarian patients (HR=0.88 [0.87-0.89]; p&amp;lt;0.05). Conclusions In a real-world population of octogenarian patients, the clinical benefit of ICD implantation for primary prevention appears diminished, considering the trade-off between ventricular arrhythmias and mortality, in both ischemic and non-ischemic cardiomyopathy patients.

Left ventricular ejection fraction and myocardial fibrosis in survivors of ventricular fibrillation and ventricular tachycardia

Abstract Background Primary prevention implantable cardioverter defibrillator (ICD) therapy is indicated in patients with a LVEF&amp;lt;35%. Increasing evidence suggests that LVEF is a poor predictor or ventricular arrhythmias, such as ventricular tachycardia (VT) or fibrillation (VF). Methods Patients hospitalized for VF (55.4%) or VT with hemodynamic compromise underwent late gadolinium enhancement cardiovascular magnetic resonance (CMR). Patients with congenital heart disease, channelopathies, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and chemotherapy-induced cardiomyopathy were excluded. Results Among patients (n=111, aged 62.1 ± 14.6 years [mean ± SD]) hospitalized for VF (55.4%) or VT with hemodynamic compromise (44.5%) only 29/111 (43.6%) had a history of cardiac disease. At the index hospitalization, an ischemic cause was identified in 69.3%, a non-ischemic cause in 24.8% and no cause emerged in 5.9%. The LVEF (39.1 ± 17.2%) was ≤35% in 55.4% and &amp;gt;35% in 44.6%. Myocardial fibrosis was present in 85.1% (LVEF≤35%: 91.1%; LVEF&amp;gt;35%: 77.8%; p = 0.0619). Conclusions A large proportion of sustained VT or VF survivors would not have previously met LVEF primary prevention criteria for ICD therapy. In this 'ICD treatment gap', myocardial fibrosis was more prevalent than a LVEF≤35%. Further studies are needed to determine whether myocardial scar rather than LVEF≤35% should be used as an indication for primary prevention ICD therapy.

DIAGNOSTIC CRITERIA FOR NON–DILATED LEFT VENTRICULAR CARDIOMYOPATHY WITH PROGNOSTIC SIGNIFICANCE

Abstract Background Non–dilated left ventricular cardiomyopathy (NDLVC) is a novel diagnostic entity defined as non–ischemic LV scarring or fatty replacement regardless of the presence of global or regional wall motion abnormalities, or isolated global LV hypokinesia without scarring. While the absence of LV dilation and systolic dysfunction are implicit, no cut–offs were proposed. Methods All patients undergoing cardiac magnetic resonance (CMR) examination at a tertiary referral center from 2012 to 2022 and meeting the definition of NDLVC were evaluated. The primary endpoint was a composite of cardiac death, sustained ventricular tachycardia (VT) or ventricular fibrillation, appropriate defibrillator intervention; the secondary endpoint included also non–sustained VT. Results The cohort included 262 patients, with 176 men (67%) and a median age of 55 years (interquartile range 44–64 years). Patients without moderate (n=243, 93%) or severe LV dilation (n=249, 95%) had a longer survival free from both endpoints. The 50% LVEF threshold identified patients with different outcomes, whereas the 55% and 60% cut–offs did not. LVEF ≥50% and no severe LV dilation predicted a better outcome independent of percent LGE in the LV, the number of LV segments with LGE, LV fibro–fatty replacement, or right ventricular involvement. LVEF ≥50% and no severe LV dilation retained an independent prognostic value even in patients with LV LGE (80% of the whole cohort). Conclusions Excluding severe LV dilation (LVEDVi &amp;gt;129 mL/m2 in men and &amp;gt;116 mL/m2 in women) and LV dysfunction (LVEF &amp;lt;50%) could enhance the prognostic utility of the NDLVC definition.

Stratification of arrhythmic risk in patients admitted for acute coronary syndrome: the role of the machine learning-derived PRAISE score

Abstract Funding Acknowledgements None. Background Patients with acute coronary syndrome (ACS) have a high arrhythmic burden, and either ventricular and supraventricular arrhythmias are very common during hospitalization[1]. Patients who develop arrhythmias show higher mortality and worse prognosis. The PRAISE (Prediction of Adverse Events Following an Acute Coronary Syndrome) score is a machine-learning based model for predicting 1-year all cause death, recurrent acute myocardial infarction and major bleedings in patients after ACS[2]. To date, its role to predict arrhythmic complications in ACS remains unknown. Purpose We hypothesized that patients with higher PRAISE score have a higher arrhythmic burden. Aim was to evaluate in a prospective protocol the PRAISE score capability for identifying patients with ACS at higher risk of arrhythmic complications during in-hospital stay. Methods A total of 365 consecutive patients admitted to our cardiac intensive care unit for ACS and undergoing percutaneous coronary intervention were enrolled. All patient was monitored by continuous electrocardiogram during hospitalization. The PRAISE score was obtained for each patient &amp;lt;24 hours from admission. Patients were divided into 2 groups based on the results of the PRAISE score for all-cause of death as patients without high PRAISE score (e.g. with low to intermediate risk, n=350) and patients with high PRAISE score (e.g. with high risk, n=15). The occurrence of atrial fibrillation (AF) and ventricular arrhythmias (VAs) up to discharge was recorded. AF was defined by detection of at least one episode of uncoordinated atrial electrical activation and irregular R-R intervals, in absence of distinct repeating P waves and with irregular atrial activations lasting at least 5 minutes. We considered as VAs all episodes of ventricular non-sustained tachycardia, sustained ventricular tachycardia and ventricular fibrillation. Results ROC curve analysis indicated a significant relationship between high PRAISE score and risk of both in-hospital AF (AUC 0.89, 95%CI 0.82-0.94, p=0.0001) and VAs (AUC 0.69, 95%CI 0.64-0.75, p=0.0001). A high PRAISE score had a specificity of 99% for AF and 92% for VAs. By Kaplan-Meier analysis, patients with high PRAISE score more frequently developed AF (30% vs 4% in those without high score; log rank p=0.00001) and VAs (77% vs 35%; log rank p=0.00001). Multivariate analysis showed that a high PRAISE score was an independent predictor of both AF (HR 4.08, 95%CI 1.14-14.58, p=0.030) and VAs (HR 2.36, 95%CI 1.08-5.14, p=0.030). Conclusions In patients hospitalized for ACS, the PRAISE score has a comprehensive capability to identify with high specificity those patients prone to develop arrhythmic events during hospitalization. This may be important in order to stratify patients with higher arrhythmic risk in whom individualized strategies may improve the clinical outcome.Baseline features of the populationKaplan-Meier anaysis

Machine learning for prediction of ventricular arrhythmia episodes from intracardiac electrograms of automatic implantable cardioverter-defibrillators

BackgroundDespite effectiveness of the implantable cardioverter-defibrillator (ICD) in saving patients with life-threatening ventricular arrhythmias (VAs), the temporal occurrence of VA after ICD implantation is unpredictable. ObjectiveThe study aimed to apply machine learning (ML) to intracardiac electrograms (IEGMs) recorded by ICDs as a unique biomarker for predicting impending VAs. MethodsThe study included 13,516 patients who received Biotronik ICDs and enrolled in the CERTITUDE registry between January 1, 2010, and December 31, 2020. Database extraction included IEGMs from standard quarterly transmissions and VA event episodes. The processed IEGM data were pulled from device transmissions stored in a centralized Home Monitoring Service Center and reformatted into an analyzable format. Long-range (baseline or first scheduled remote recording), mid-range (scheduled remote recording every 90 days), or short-range predictions (IEGM within 5 seconds before the VA onset) were used to determine whether ML-processed IEGMs predicted impending VA events. Convolutional neural network classifiers using ResNet architecture were employed. ResultsOf 13,516 patients (male, 72%; age, 67.5 ± 11.9 years), 301,647 IEGM recordings were collected; 27,845 episodes of sustained ventricular tachycardia or ventricular fibrillation were observed in 4467 patients (33.0%). Neural networks based on convolutional neural networks using ResNet-like architectures on far-field IEGMs yielded an area under the curve of 0.83 with a 95% confidence interval of 0.79–0.87 in the short term, whereas the long-range and mid-range analyses had minimal predictive value for VA events. ConclusionIn this study, applying ML to ICD-acquired IEGMs predicted impending ventricular tachycardia or ventricular fibrillation events seconds before they occurred, whereas midterm to long-term predictions were not successful. This could have important implications for future device therapies.

Impact of Outpatient Beta Blocker Therapy Adjustment on Tachyarrhythmias in Patients With Heart Failure With Reduced Ejection Fraction Admitted for Acute Decompensated Heart Failure.

Background: Limited data exists to evaluate the optimal management of outpatient beta blocker therapy when patients with heart failure with reduced ejection fraction (HFrEF) are admitted for acute decompensated heart failure (ADHF). Objective: This study aimed to compare the effects of holding or decreasing the dose of outpatient beta blocker therapy vs continuation of therapy on rates of tachyarrhythmias during admission for ADHF. Methods: This single-center, retrospective cohort study divided patients with HFrEF (left ventricular ejection fraction less than or equal to 40%) admitted for ADHF into two cohorts: one that had their outpatient beta blocker continued at the same dose upon admission and one that had it held or dose decreased. The primary outcome was a composite of non-sustained or sustained ventricular tachycardia, ventricular fibrillation, or atrial fibrillation or flutter with rapid ventricular response during the hospitalization. Secondary outcomes included the individual tachyarrhythmias in the primary outcome, in-hospital mortality, and 90-day re-admission for heart failure. Results: Of the 137 patients included, 82 were in the continuation cohort and 55 in the discontinuation/reduction cohort. The median length of stay was 5.3 days (interquartile range, 3.8-7.6). No significant difference in the primary composite outcome was found between the discontinuation/reduction and continuation cohorts (29.1% vs 22.0%; relative risk [95% confidence interval], 1.33 [.74-2.37]; P = .420). No significant differences were seen between the two cohorts for any of the secondary outcomes. Conclusion: Beta blocker therapy adjustment on admission for ADHF may not affect the occurrence of tachyarrhythmias in patients with HFrEF.

Prognostic value of noninvasive programmed stimulation in primary prevention implantable cardioverter‐defibrillator recipients

AbstractBackgroundImplantable cardioverter‐defibrillator (ICD) offers an opportunity to study inducibility of ventricular tachycardia (VT) or ventricular fibrillation (VF) by performing noninvasive programmed ventricular stimulation (NIPS). Whether NIPS can predict future arrhythmic events or mortality in patients with primary prevention ICD, has not yet been examined.MethodsFrom the NIPS‐ICD study (ClinicalTrials ID: NCT02373306) 41 consecutive patients (34 males, age 64 ± 11 years, 76% ischemic cardiomyopathy [ICM]) had ICD for primary prevention indication. Patients underwent NIPS using a standardized protocol of up to three premature extrastimuli at 600, 500 and 400 ms drive cycle lengths. NIPS was classified as positive if sustained VT or VF was induced. The study endpoint was occurrence of sustained VT/VF during the follow‐up.ResultsAt baseline NIPS, VT/VF was induced in 8 (20%) ICM patients. During the 5‐year follow‐up, the VT/VF occurred in 7 (17%) patients, all with ICM. The difference between NIPS‐inducible versus NIPS‐noninducible patients regarding VT/VF occurrence did not meet statistical significance (38% vs. 12%, log rank test p = .11). After a 5‐year follow‐up, the mortality rate was significantly higher in patients who had VT/VF induced at NIPS versus no VT/VF at NIPS (38% vs. 12%, p = .043). The occurrence of a composite endpoint consisting of VT/VF recurrence or death in patients with ICM was also most frequent in the NIPS‐inducible group (75% vs. 35%, p = .037).ConclusionsInducibility of VT/VF during NIPS in ICM patients with primary prevention ICD is associated with higher mortality and higher incidence of composite endpoint consisting of death or VT/VF during a long‐term observation.

Clinical and cardiac MRI characteristics: prognosis in patients with alcoholic cardiomyopathy

Alcoholic cardiomyopathy (ACM) is recognized as a type of non-ischemic dilated cardiomyopathy (DCM). To date, the clinical prognosis of ACM remains a topic of debate in previous studies and there are limited studies on its cardiac MRI characteristics. The aim of this study was to summarize the clinical and MRI features of ACM patients and to identify the predictors of adverse prognosis based on clinical characteristics and MRI imaging findings. Adult patients who were clinically diagnosed with ACM and underwent enhanced CMR between September 2015 and August 2022 were retrospectively enrolled. The primary endpoints were major adverse cardiovascular events, including cardiac-related death, heart transplantation, hospitalization for heart failure and life-threatening ventricular arrhythmias (sustained ventricular tachycardia, ventricular fibrillation, or ICD shock). The risk factors associated with these primary end points were identified using multivariable Cox analysis. A total of 62 ACM patients (50±9 years, 62 men) were included. The majority of patients presented with symptoms of heart failure. Over a median follow-up period of 30.3 months (IQR 12.2-57.7 months), 24 patients reached the primary endpoints. For clinical variables, multivariable analysis showed that drinking duration (HR=1.05; 95%CI:1.01, 1.11; p=0.03) and persistent drinking (HR=3.71; 95%CI:1.46, 9.44; p=0.01) were associated with MACE. For CMR variables, late gadolinium enhancement (LGE) percent (HR = 1.09; 95% CI: 1.03, 1.14; p<0.001) stood out as an independent predictor for MACE. In ACM patients, persistent drinking and cardiac MRI-defined myocardial scar were associated with adverse outcomes such as cardiac death, heart transplantation, hospitalization for heart failure or life-threatening ventricular arrhythmias.

Safety and potential usefulness of sequential intracoronary acetylcholine and ergonovine administration for spasm provocation testing.

Although guidelines recommend intracoronary acetylcholine (ACh) and ergonovine (ER) provocation testing for diagnosis of vasospastic angina, the feasibility and safety of sequential (combined) use of both pharmacological agents during the same catheterization session remain unclear. In this study, we investigated the feasibility and safety of sequential intracoronary ACh and ER administration for coronary spasm provocation testing. The study included 235 patients who showed positive results on ACh and ER provocation testing. Initial intracoronary ACh administration was followed by ER administration for left coronary artery (LCA) spasm provocation testing. Subsequently, the right coronary artery (RCA) was subjected to sequential ACh and ER administration for provocation testing. The primary outcome of the study was the safety of sequential intracoronary ACh and ER provocation testing, which was assessed based on a composite of all-cause death, sustained ventricular tachycardia and fibrillation, and cardiogenic shock. Even in patients with negative results on sequential intracoronary ACh and ER provocation testing in the LCA and only ACh administration into the RCA, additional administration of ER into the RCA showed a positive provocation test result in 33 of 235 (14.0%) patients; three (1.3%) patients developed adverse effects (cardiogenic shock occurred in all cases) during LCA provocation testing. We observed no deaths attributable to spasm provocation testing. Sequential administration of intracoronary ACh and ER was associated with a relatively low major complication rate and may be safe and potentially useful for diagnosis of vasospastic angina.

QRS Morphology and the Risk of Ventricular Tachyarrhythmia in Cardiac Resynchronization Therapy Recipients

BackgroundThere are conflicting data on the effect of cardiac resynchronization therapy with a defibrillator (CRT-D) on the risk of life-threatening ventricular tachyarrhythmia in heart failure patients. ObjectivesThe authors aimed to assess whether QRS morphology is associated with risk of ventricular arrhythmias in CRT recipients. MethodsThe study population comprised 2,862 patients implanted with implantable cardioverter defibrillator (ICD)/CRT-D for primary prevention who were enrolled in 5 landmark primary prevention ICD trials (MADIT-II [Multicenter Automated Defibrillator Implantation Trial], MADIT-CRT [Multicenter Automated Defibrillator Implantation Trial-Cardiac Resynchronization Therapy], MADIT-RIT [Multicenter Automated Defibrillator Implantation Trial-Reduction in Inappropriate Therapy], MADIT-RISK [Multicenter Automated Defibrillator Implantation Trial-RISK], and RAID [Ranolazine in High-Risk Patients With Implanted Cardioverter Defibrillators]). Patients with QRS duration ≥130 ms were divided into 2 groups: those implanted with an ICD only vs CRT-D. The primary endpoint was fast ventricular tachycardia (VT)/ventricular fibrillation (VF) (defined as VT ≥200 beats/min or VF), accounting for the competing risk of death. Secondary endpoints included appropriate shocks, any sustained VT or VF, and the burden of fast VT/VF, assessed in a recurrent event analysis. ResultsAmong patients with left bundle branch block (n = 1,792), those with CRT-D (n = 1,112) experienced a significant 44% (P < 0.001) reduction in the risk of fast VT/VF compared with ICD-only patients (n = 680), a significantly lower burden of fast VT/VF (HR: 0.55; P = 0.001), with a reduced burden of appropriate shocks (HR: 0.44; P < 0.001). In contrast, among patients with non-left bundle branch block (NLBBB) (N = 1,070), CRT-D was not associated with reduction in fast VT/VF (HR: 1.33; P = 0.195). Furthermore, NLBBB patients with CRT-D experienced a statistically significant increase in the burden of fast VT/VF events compared with ICD-only patients (HR: 1.90; P = 0.013). ConclusionsOur data suggest a potential proarrhythmic effect of CRT among patients with NLBBB. These data should be considered in patient selection for treatment with CRT.

Factors Responsible for Worse Outcomes in Stemi Patients with Early vs Delayed Treatment Presenting in a Tertiary Care Center

Objectives: The aim of the study is to compare the outcomes among STEMI cases with early treatment vs delayed treatment. To identify the contributing factors behind treatment delays and worse outcomes following STEMI symptoms.&#x0D; Methodology: It was a prospective comparative study on 186 patients with consecutive (non-probability) sampling. Two groups of cases were made as per their time to get admitted to the hospital (i.e. within 2 hours of symptom onset = Group-A; after 2 hours of symptom onset = Group-B). Patients were asked for factors causing a delay in treatment after the onset of symptoms and were monitored for STEMI outcomes.&#x0D; Results: The mean age of all patients was 46.62 ± 9.76 years and there were 140(75.27%) male and 46(24.73%) female, and male to female ratio 3:1.Factors significant for delayed treatment versus non- delayed treatment were poor social economic status (65.6% versus 20.4%), history of chronic stable angina (33.3% versus 11.8%), delayed response in the emergency room (20.4% versus 8.6%), delayed ECG acquisition (26.9% versus 8.6%), delayed ECG interpretation (25.8% versus 4.3%), pain at night 12:00 to 6:00 am (21.5% versus 9.7%) and belief that the chest pain is non-cardiac (26.9% versus 3.2%). Acute heart failure was significantly greater in group B (9.7%) in comparison with group-A (2.2%), Re- infarction was 18.3% in group B in comparison with 7.5% group-A. Similarly sustained ventricular tachycardia and ventricular fibrillation and in hospital mortality were higher in group B (12.9%, 14 % and 12.9% respectively).&#x0D; Conclusion: Our study highlights that while most post-AMI patients receive the recommended minimum statin therapy, the inadequate practice of lipid assessment may compromise therapy optimization and raise the risk of subsequent events.

Arrhythmic Risk in Biventricular Pacing Compared With Left Bundle Branch Area Pacing: Results From the I-CLAS Study.

Left bundle branch area pacing (LBBAP) may be associated with greater improvement in left ventricular ejection fraction and reduction in death or heart failure hospitalization compared with biventricular pacing (BVP) in patients requiring cardiac resynchronization therapy. We sought to compare the occurrence of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and new-onset atrial fibrillation (AF) in patients undergoing BVP and LBBAP. The I-CLAS study (International Collaborative LBBAP Study) included patients with left ventricular ejection fraction ≤35% who underwent BVP or LBBAP for cardiac resynchronization therapy between January 2018 and June 2022 at 15 centers. We performed propensity score-matched analysis of LBBAP and BVP in a 1:1 ratio. We assessed the incidence of VT/VF and new-onset AF among patients with no history of AF. Time to sustained VT/VF and time to new-onset AF was analyzed using the Cox proportional hazards survival model. Among 1778 patients undergoing cardiac resynchronization therapy (BVP, 981; LBBAP, 797), there were 1414 propensity score-matched patients (propensity score-matched BVP, 707; propensity score-matched LBBAP, 707). The occurrence of VT/VF was significantly lower with LBBAP compared with BVP (4.2% versus 9.3%; hazard ratio, 0.46 [95% CI, 0.29-0.74]; P<0.001). The incidence of VT storm (>3 episodes in 24 hours) was also significantly lower with LBBAP compared with BVP (0.8% versus 2.5%; P=0.013). Among 299 patients with cardiac resynchronization therapy pacemakers (BVP, 111; LBBAP, 188), VT/VF occurred in 8 patients in the BVP group versus none in the LBBAP group (7.2% versus 0%; P<0.001). In 1194 patients with no history of VT/VF or antiarrhythmic therapy (BVP, 591; LBBAP, 603), the occurrence of VT/VF was significantly lower with LBBAP than with BVP (3.2% versus 7.3%; hazard ratio, 0.46 [95% CI, 0.26-0.81]; P=0.007). Among patients with no history of AF (n=890), the occurrence of new-onset AF >30 s was significantly lower with LBBAP than with BVP (2.8% versus 6.6%; hazard ratio, 0.34 [95% CI, 0.16-0.73]; P=0.008). The incidence of AF lasting >24 hours was also significantly lower with LBBAP than with BVP (0.7% versus 2.9%; P=0.015). LBBAP was associated with a lower incidence of sustained VT/VF and new-onset AF compared with BVP. This difference remained significant after adjustment for differences in baseline characteristics between patients with BVP and LBBAP. Physiological resynchronization by LBBAP may be associated with lower risk of arrhythmias compared with BVP.

Abstract 12715: Can 18F-Fluorodeoxyglucose Uptake Stratify the Risk of the Patients With Cardiac Sarcoidosis After Initiation of Immunosuppressive Therapy?

Introduction: While 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is well-established for diagnosing cardiac sarcoidosis (CS) initially, its potential as a risk stratification tool for patients receiving immunosuppressive therapy remains controversial. Hypothesis: We aim to assess the prognostic value of FDG-PET in CS patients after 12 months of corticosteroid treatment. Methods: Our study consists of a retrospective review of clinical data and patient outcomes of stable CS cases that underwent FDG-PET following 12 months of corticosteroid treatment initiation. We excluded patients in the previous six months who had a heart failure hospitalization, sustained ventricular tachycardia (SVT) or ventricular fibrillation (VF), recent pacemaker implantation or upgrade, changes in corticosteroid dosage, or newly introduced additional immunosuppressive therapy. Major adverse cardiac events (MACE) include a composite of cardiac death, onset of SVT/VF, appropriate implantable cardioverter-defibrillator intervention, heart failure hospitalization, and cardiac functional deterioration. Results: Among the 72 analyzed patients, 35 exhibited cardiac accumulation in FDG-PET scans. Over an average of 49 (22-76) months, 19 patients experienced MACE. The occurrence of MACE was higher in the reduced left ventricle ejection fraction (LVEF) group (&lt;50%) than in the preserved LVEF group (≥50%) (51.5% vs. 5.1%, Log rank p &lt;0.001). Similarly, MACE was more common in the SVT/VF (+) group as compared to the SVT/VF (-) group (50.0% vs. 23.4%, Log rank p =0.041). However, the presence of cardiac accumulation in FDG-PET showed no significant correlation (Log rank p =0.718). Conclusions: The presence of residual cardiac accumulation after initiation of immunosuppressive therapy was not associated with the prognosis of the patients with CS. Established predictors, such as reduced LVEF and the occurrence of SVT/VF, remain integral in predicting MACE.

Abstract 16401: Optimizing ChatGPT to Detect VT Recurrence From Complex Medical Notes

Introduction: Large language models (LLMs), such as ChatGPT, have remarkable ability to interpret natural language using text questions (prompts) applied to gigabytes of data in the world wide web. However, the performance of ChatGPT is less impressive when addressing nuanced questions from finite repositories of lengthy, unstructured clinical notes (Fig A). Hypothesis: The performance of ChatGPT to identify sustained ventricular tachycardia (VT) or fibrillation after ablation from free-text medical notes is improved by optimizing the question and adding in-context sample notes with correct responses (‘prompt engineering’). Methods: We curated a dataset of N = 125 patients with implantable defibrillators (32.0% female, LVEF 48.9±13.9%, 61.7±14.0 years), split into development (N = 75) and testing (N = 50) sets of 307 and 337 notes, with 256.8±95.1 and 289.8±103 words, respectively. Notes were deidentified. Gold standard labels for recurrent VT (Yes, No, Unknown) were provided by experts. We applied GPT-3.5 to the test set (N=337 notes), using 1 of 3 prompts (“Does the patient have sustained VT or VF after ablation” or 2 others), systematically adding 1-5 “training” examples, and repeating experiments 10 times (51,561 inquiries). Results: At baseline, GPT achieved an F1 score of 38.6%±19.4% (mean across 3 prompts; Fig B). Increasing the number of examples progressively improved mean accuracy and reduced variance. The optimal result was the illustrated prompt plus 5 in-context examples, with an F1 score of 84.6%±6.4% (p&lt;0.05). Conclusions: ChatGPT can accurately identify VT recurrence from small numbers of complex medical notes with optimal prompt engineering. Future studies should define optimal context for different medical questions and domains. These findings pave the way for automated analysis of large medical repositories to broadly improve decision making.

Lifetime exercise dose and ventricular arrhythmias in patients with mitral valve prolapse.

Patients with mitral valve prolapse (MVP) have high risk of life-threatening ventricular arrhythmias (VAs). Data on the impact of exercise on arrhythmic risk in these patients are lacking. We explored whether lifetime exercise dose was associated with severe VA and with established risk factors in patients with MVP. Furthermore, we explored the circumstances at the VA event. In this retrospective cohort study, we included patients with MVP and assessed lifetime exercise dose as metabolic equivalents of task (MET) hours/week. Severe VA was defined as sustained ventricular tachycardia or fibrillation, aborted cardiac arrest, and appropriate shock by a primary preventive implantable cardioverter defibrillator. We included 136 MVP patients (48 years [interquartile range (IQR) 35-59], 61% female), and 17 (13%) had previous severe VA. The lifetime exercise dose did not differ in patients with and without severe VA (17 MET h/week [IQR 9-27] vs. 14 MET h/week [IQR 6-31], P = 0.34). Lifetime exercise dose > 9.6 MET h/week was a borderline significant marker for severe VA (OR 3.38, 95% CI 0.92-12.40, P = 0.07), while not when adjusted for age (OR 2.63, 95% CI 0.66-10.56, P = 0.17). Ventricular arrhythmia events occurred most frequently during wakeful rest (53%), followed by exercise (29%) and sleep (12%). We found no clear association between moderate lifetime exercise dose and severe VA in patients with MVP. We cannot exclude an upper threshold for safe levels of exercise. Further studies are needed to explore exercise and risk of severe VA.

Ventricular Tachycardia.

This scenario was developed to educate emergency medicine residents on the diagnosis and management of ventricular tachycardia (VT) that is refractory to single dose anti-arrhythmic management. Electrical storm, defined as three or more episodes of sustained VT, ventricular fibrillation, or appropriate shocks from an implantable cardioverter defibrillator within 24 hours,1 has a mortality rate up to 14% in the first 48 hours.2 Ventricular tachycardia may present in a heterogenous fashion, not only with stable versus unstable clinical presentations, but also with different electrocardiographic morphologies and etiologies.1 Understanding how to rapidly diagnose, treat, and utilize second or third-line treatments is vital in the setting of refractory ventricular tachycardia rather than relying on the success of first-line agents. Appreciation for what medications are readily available in your crash cart and medication dispensing cabinet is critical for timely management for refractory ventricular tachycardia. At the conclusion of the simulation session, learners will be able to: 1) identify the different etiologies of VT, including structural heart disease, acute ischemia, and acquired or congenital QT syndrome; 2) describe confounding factors of VT, such as electrolyte abnormalities and sympathetic surge; 3) describe how to troubleshoot an unsuccessful synchronized cardioversion, including checking equipment connections, increasing delivered energy, and changing pad placement; 4) compare and contrast treatments of VT based on suspected underlying etiology; 5) describe reasons to activate the cardiac catheterization lab other than occlusive myocardial infarction; and 6) identify appropriate disposition of the patient to the cardiac catheterization lab. This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on the diagnosis, differential diagnosis, and management of VT. Debriefing methods may be left to the discretion of participants, but the authors have utilized advocacy-inquiry techniques. This scenario may also be run as an oral board case. Our residents are provided a survey at the completion of the debriefing session so they may rate different aspects of the simulation, as well as provide qualitative feedback on the scenario. The local institution's simulation center's electronic feedback form is based on the Center of Medical Simulation's Debriefing Assessment for Simulation in Healthcare (DASH) Student Version Short Form3 with the inclusion of required qualitative feedback if an element was scored less than a 6 or 7. Twelve learners completed a feedback form. This session received 6 and 7 scores (consistently effective/very good and extremely effective/outstanding, respectively) other than three isolated 5 scores. The lowest average score was 6.67 for "Before the simulation, the instructor set the stage for an engaging learning experience." The highest average score was 7 for "The instructor helped me see how to improve or how to sustain good performance." The form also includes an area for general feedback about the case at the end. Illustrative examples of feedback include: "Excellent care and debrief." Specific scores are available upon request. This is a cost-effective method for reviewing VT diagnosis and management. The case may be modified for appropriate audiences, such as describing what medications may be readily available in a free-standing emergency department or pre-hospital setting. Medical simulation, ventricular tachycardia, cardiac emergencies, dysrhythmias, cardiology, emergency medicine.

Incidence, Predictors, and Outcome Associated With Ventricular Tachycardia or Fibrillation in Patients Undergoing Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction.

The characteristics and clinical outcomes associated with sustained ventricular tachycardia and fibrillation (VT/VF) in Japanese acute myocardial infarction (AMI) patients remain unknown. Consecutive AMI patients (n=1,941) transferred to the Hirosaki University Hospital and treated with primary percutaneous coronary intervention (PCI) within 12 h of onset were retrospectively studied. The incidence of VT/VF during hospitalization was 8.3%, and 75% of cases occurred by the end of PCI. Independent predictors associated with VT/VF occurrence by the end of PCI and after PCI, respectively, were identified. Additionally, the differences between patients with VT and VF were examined, which revealed that the characteristics of patients and predictors for VT and VF were clearly different. Additionally, the QRS duration during VT was measured, which demonstrated the possible involvement of Purkinje fibers for VT in the acute phase of AMI. Of the patients with VT/VF, 12% required ECMO support due to refractory VT/VF despite intravenous antiarrhythmic agents such as β-blockers, amiodarone, and nifekalant. Among the patients discharged alive, 1,690 were followed up for a mean of 3.7 years. VT/VF occurrence during hospitalization did not affect the mid-term clinical outcomes even in patients with VT. The results clearly indicated that VT/VF is still a serious complications of AMI. We need to identify patients at high risk of developing VT/VF for careful observation and appropriate intervention.

Prognostic significance of the Holter-derived T-wave variability in patients with ventricular tachyarrhythmias complicating acute coronary syndrome-TWIST study.

We aimed to investigate the association between ventricular repolarization instability and sustained ventricular tachycardia and ventricular fibrillation (VT/VF) occurring within 48 h (acute-phase VT/VF) after the onset of acute coronary syndrome (ACS) and the prognostic role of repolarization instability and heart rate variability (HRV) after discharge from the hospital. We studied 572 ACS patients with a left ventricular ejection fraction >35%. The ventricular repolarization instability was assessed by the beat-to-beat T-wave amplitude variability (TAV) using high-resolution 24-h Holter ECGs recorded at a median of 11 days from the date of admission. We calculated the HRV parameters including the deceleration capacity (DC) and non-Gaussian index calculated on a 25 s timescale (λ25s). The DC and λ25s were dichotomized based on previous studies' thresholds. Acute-phase VT/VF developed in 43 (7.5%) patients. In-hospital mortality was significantly higher among VT/VF patients (4.7% vs. 0.9%, p = .03). An adjusted logistic model showed that the maximum TAV (odds ratio 1.02, 95% confidence interval [CI] 1.00-1.29, p = .04) was associated with acute-phase VT/VF. During a median follow-up period of 2.1 years, 19 (3.3%) patients had cardiac deaths or resuscitated cardiac arrest. Acute-phase VT/VF (p = .12) and TAV (p = .72) were not significant predictors of survival. An age and sex-adjusted Cox model showed that the DC (p < .01), λ25s (p < .01), and emergency coronary intervention (p < .01) were independent predictors. T-wave amplitude variability was associated with acute-phase VT/VF, but the TAV was not predictive of survival post-discharge. The DC, λ25s, and emergency coronary intervention were independent predictors of survival.