Risk Stratification For Sudden Death Research Articles

Kiosk 5R-FB-07 - Left Atrial Strain Assessed by Cardiac MRI Improves Risk Stratification of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Kiosk 5R-FB-07 - Left Atrial Strain Assessed by Cardiac MRI Improves Risk Stratification of Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Prediction of Sudden Death Risk in Patients with Congenital Heart Diseases.

Risk stratification for sudden death should be discussed with patients with congenital heart disease at each stage of personal and cardiac development. For most patients, risk is low through teenage years and the critical factors to consider are anatomy, ventricular function, and symptoms. By adulthood, these are supplemented by screening for atrial arrhythmias, ventricular arrhythmias, and pulmonary hypertension. Therapies include medication, ablation, and defibrillator placement.

Prognosis of programmed ventricular stimulation in adult patients with syncope of unexplained origin: A historical cohort.

Programmed ventricular stimulation (PVS) during electrophysiological study (EPS), is a globally accepted tool for risk stratification of sudden cardiac death (SCD) in some specific clinical situations. The aim of this study was to evaluate the prognosis of ventricular arrhythmia induction in a cohort of patients with syncope of undetermined origin (SUO). This is a historical cohort study in a population of patients with SUO referred for EPS between the years 2008-2021. In this interval, 575 patients underwent the procedure. Patients with induced ventricular arrhythmias had a higher occurrence of structural heart disease (36.7% vs. 76.5%), ischemic heart disease (28.2 vs. 57.1%), heart failure (15.5% vs. 34.4%), and lower left ventricular ejection fraction (59.16% vs. 47.51%), when compared to the outcome with a negative study. PVS triggered ventricular arrhythmias in 98 patients, 62 monomorphic and 36 polymorphic. During a median follow-up of 37.6 months, 100 deaths occurred. Only the induction of sustained ventricular arrhythmias showed a significant association with the primary outcome (all-cause mortality) with a p value <.001. After the performance of EPS, 142 patients underwent cardioverter-defibrillator (ICD) implantation. At study follow-up, 30 patients had therapies by the device. Only the induction of sustained monomorphic ventricular arrhythmia showed statistically significant association with appropriate therapies by the device (p = .012). In patients with SUO, the induction of sustained monomorphic ventricular arrhythmia after programmed ventricular pacing is related to a worse prognosis, with a higher incidence of mortality and appropriate therapies by the ICD.

Fractional flow reserve in anomalous aortic origin of coronary arteries to evaluate hemodynamic consequences of high risk anatomical features

Abstract Introduction In patients with anomalous aortic origin of a coronary artery (AAOCA) fractional flow reserve (FFR) can be performed for further risk stratification of myocardial ischemia and sudden cardiac death. The aim of this study was to evaluate the hemodynamic consequences (accessed with FFR) of the high-risk anatomical features in AAOCA. Methods In this prospective cohort study, all consecutive patients with AAOCA in whom diagnostic work-up according to the MuSCAT trial, including FFR, was performed between July 2020 and January 2023 in our tertiary AAOCA referral center, were included. Presence and length of the intramural segment was assessed using the interluminal space (ILS) on the CTA and orifice geometry using IVUS. Results Thirty patients, 57% female and mean age at AAOCA diagnosis of 48.7±15.3 years, were included. Twenty-seven (90%) patients presented with an anomalous aortic origin of the right coronary artery. FFR adenosine was measured in all patients (Figure 1), and showed a significant relation with: 1. hypoplasia of the proximal segment on CTA (R=0.400, p=0.029); 2. the ILS at 2mm from the ostium on CTA (R=0.517, p=0.003); 3. the length of the intramural course on CTA (R=0.500, p=0.005); 4. the orifice shape on IVUS (R=0.460, p=0.011) and 5. the minimal lumen area on IVUS (R=0.371, p=0.044). Conclusions FFR was significantly reduced in AAOCA with the following high-risk anatomical features: increased hypoplasia of the proximal segment on CTA, lower ILS at 2mm from the ostium on CTA, longer intramural course on CTA, increased slitlike orifice shape on IVUS and lower minimal lumen area on IVUS. These anatomical high-risk features appear to be hemodynamically relevant in the pathophysiology of AAOCA.Figure 1

Using the 3D architecture of scar to predict life-threatening ventricular arrhythmias, still a long way to go

Abstract Background Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias. Purpose The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD). Methods We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 16 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock), sustained ventricular tachycardia or SCD. Results A total of 116 patients were analysed (mean age 66 ± 14 years; 81% male; mean LVEF 34 ± 14%; 74 patients with ischemic and 42 with non-ischemic cardiomyopathy; 40 patients received a device in the setting of secondary prevention). During a median follow-up of 2.3 years (IQR 1.3 – 3.3 years) there were 23 events (18 appropriate ICD therapies [9 shocks and 9 ATP], 3 episodes of VT under the threshold for ICD therapy and 2 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values &amp;gt; 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 26 patients did not show any channel. Four of these (all with non-ischemic LGE) experienced an arrhythmic event, yielding a negative predictive value of 83% (95% CI 64-93%) for the absence of channels. Conclusion In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.

Perfomance of sudden cardiac death prediction strategies before and after Septal Reduction Strategies in patients with Hypertrophic Cardiomyopathy

Abstract Background Actual sudden death (SD) risk stratification strategies for Hypertrophic Cardiomyopathy have not been validated for patients after a septal reduction treatment (SRT). Therefore, it is largely unresolved the quantification of the ventricular arrhythmias (VA) burden after an SRT and how risk stratification should be performed in such patients. Purpose To evaluate the performance of ESC SD Risk stratification model and AHA ACC Risk Factors for SD in the identification of patients with lethal ventricular arrhythmias after SRT. Methods Data from 11 high-volume HCM specialty centers from the international SHaRe Registry were used to describe the natural history of patients with SRT. Patients were followed from SRT until last follow-up or meeting the composite outcome of ventricular arrhythmias (sudden cardiac death (SCD), resuscitated cardiac arrest, or appropriate implantable cardioverter-defibrillator (ICD) therapy). Cox proportional hazards models were used to identify predictors of prognosis and incident development. Calculation of SD score was performed before the SRT and at 1 year from the procedure. Results Of the 10385 patients part of the ShaRe Registry, 1835 (18%, 968 (53%) males) underwent a SRT during a median follow-up of 6.8 (IQR 3.4-9.8). A total of 455 (25%) had Alcohol Septal Ablation (ASA) and 1377 (75%) had myectomy. Patients who underwent myectomy were younger (49±18 vs 56±15 years, p&amp;lt;0.01), more frequent with a sarcomeric mutation (396 (29%) vs 111 (24%), p&amp;lt;0.01). Over 6.8 years after the procedure, 77 (4%) died because of HCM (0.6%/year) and 87 (5%) presented a composite VA outcome (0.7%/year). Development of the composite VA event was associated with younger age at procedure (38±20 vs 54±18 years, p&amp;lt;0.01), the development of a LV EF&amp;lt; 50% (29 (33%) vs 351 (20%), p&amp;lt;0.01), a more severely dilated LA (47±7 vs 43±11 years, p&amp;lt;0.01) and greater LV maximal wall thickness (24±6 vs 21±6 years, p&amp;lt;0.01). Significant predictor of the composite VA outcome was the presence of a LA diameter ³ 45 mm (HR, 2.6 [95% CI, 1.7–3.5]). Patients who presented the VA outocome were classified according to ESC SCD Risk pre and post SRT as: 40 (46%) as high risk, 31 (36%) as intermidiate risk, 16 (18%) as low risk pre intervention and 26 (46%) as high risk, 41 (47%) as intermidiate risk, 20 (18%) as low risk post procedure. AHA ACC SCD risk factors pre and post SRT classified patients as: 56 (64%) as class IIA 25 (29%) as Clas IIB, 6 (7%) as Class III and post SRT 42 (48%) as Class IIA, 31(36%) as Class IIB, 14 (16%) as Class III. Conclusions Current stratification strategies potentially underestimate the risk of SD pre and post SRT. Specifically, ESC SD risk strategies underperformed in the identification of intermidiate high risk patient, whereas AHA ACC were capable of identifying 84% of patients who had a malignant VA.

Appropriate time for ejection fraction reassessment after revascularization in patients with left ventricular dysfunction for risk stratification of sudden cardiac death.

Appropriate time for ejection fraction (EF) reassessment after revascularization in patients with left ventricular dysfunction has not been investigated comprehensively, although 3 months after revascularization is recommended to stratify the risk of sudden cardiac death (SCD). EF reassessed within different timeframe after revascularization may have incosistent contribution for risk stratification of SCD. Patients who had EF ≤ 40% before revascularization and had EF reassessment at least once during follow-up were included. The role of early (<3 months) versus late (3-12 months) EF measurements in prediction of all-cause mortality and SCD were compared. A total of 1589 patients were identified. EF reassessed <3 months was lower than EF reassessed within 3-12 months (42.1 ± 9.7% vs. 45.8 ± 10.8%; p < .01). Among 1069 patients who had EF reassessed <3 months, EF ≤ 35% was associated with a higher risk of all-cause mortality (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.22-2.29; p < .01), but had no association with the risk of SCD (HR, 1.44; 95% CI, 0.84-2.48; p = .18). By contrast, among 595 patients who had EF reassessed within 3-12 months, EF ≤ 35% was associated with higher risks of both all-cause death (HR, 1.81; 95% CI, 1.06-3.10; p = .03) and SCD (HR, 2.71; 95% CI, 1.31-5.61; p < .01). The relative contribution of SCD to all-cause death was higher in patients with EF ≤ 35% than patients with EF > 35% when EF was reassessed within 3-12 months (p = .04). However, when EF was reassessed <3 months, the mode of death was similar in patients with EF ≤ 35% versus >35% (p = .85). 3 to 12 months after revascularization may be appropriate for cardiac function reassessment and SCD risk stratification.

Risk assessment of post-myocardial infarction patients with preserved ejection fraction using 45-min short resting Holter electrocardiographic recordings.

Risk stratification for sudden cardiac death in post-myocardial infarction (post-MI) patients remains a challenging task. Several electrocardiographic noninvasive risk factors (NIRFs) have been associated with adverse outcomes and were used to refine risk assessment. This study aimed to evaluate the performance of NIRFs extracted from 45-min short resting Holter ECG recordings (SHR), in predicting ventricular tachycardia inducibility with programmed ventricular stimulation (PVS) in post-MI patients with preserved left ventricular ejection fraction (LVEF). We studied 99 post-MI ischemia-free patients (mean age: 60.5 ± 9.5 years, 86.9% men) with LVEF ≥40%, at least 40 days after revascularization. All the patients underwent PVS and a high-resolution SHR. The following parameters were evaluated: mean heart rate, ventricular arrhythmias (premature ventricular complexes, couplets, tachycardias), QTc duration, heart rate variability (HRV), deceleration capacity, heart rate turbulence, late potentials, and T-wave alternans. PVS was positive in 24 patients (24.2%). HRV, assessed by the standard deviation of normal-to-normal R-R intervals (SDNN), was significantly decreased in the positive PVS group (42 ms vs. 51 ms, p = .039). SDNN values <50 ms were also associated with PVS inducibility (OR 3.081, p = .032 in univariate analysis, and 4.588, p = .013 in multivariate analysis). No significant differences were identified for the other NIRFs. The presence of diabetes, history of ST-elevation MI (STEMI) and LVEF <50% were also important predictors of positive PVS. HRV assessed from SHR, combined with other noninvasive clinical and echocardiographic variables (diabetes, STEMI history, LVEF), can provide an initial, practical, and rapid screening tool for arrhythmic risk assessment in post-MI patients with preserved LVEF.

Analysis of risk stratification and prevention of sudden death in pediatric patients with hypertrophic cardiomyopathy: Dilemmas and clarity.

Hypertrophic cardiomyopathy (HCM) has been considered the most common cause of sudden death (SD) in the young. However, introduction of implantable cardioverter-defibrillators (ICDs) in HCM has proved highly effective and the mainstay of preventing SD in children, adolescents, and adults by terminating malignant ventricular tachyarrhythmias. Nevertheless, ICD decision making is generally regarded as more difficult in pediatrics, and the strategy for selecting ICD patients from this population remains without consensus. Prospective studies in HCM children and adolescents have shown the American Heart Association/American College of Cardiology traditional major risk marker strategy to be reliable with >90% sensitivity in selecting patients for SD prevention. International data in >2000 young HCM patients assembled over 20 years who were stratified by major risk markers showed ICDs effectively prevented SD in 20%. Alternatively, novel quantitative risk scoring initiatives provide 5-year risk estimates that are potentially useful as adjunctive tools to facilitate discussion of prophylactic ICD risks vs benefit but are as yet unsupported by prospective outcome studies. Risk scoring strategies are characterized by reasonable discriminatory statistical power (C-statistic 0.69-0.76) for identifying patients with SD events but with relatively low sensitivity, albeit with specificity comparable with the risk marker strategy. While some reticence for obligating healthy-appearing young patients to lifelong device implants is understandable, underutilization of the ICD in high-risk children and adolescents can represent a lost opportunity for fulfilling the long-standing aspiration of SD prevention. This review provides a critical assessment of the current strengths and weaknesses of SD risk stratification strategies in young HCM patients in an effort to clarify clinical decision making in this challenging subpopulation.

Compliance With Risk Stratification for Sudden Cardiac Death in Patients With Hypertrophic Cardiomyopathy

Compliance With Risk Stratification for Sudden Cardiac Death in Patients With Hypertrophic Cardiomyopathy

Validation of the Risk Stratification for Sudden Cardiac Death in Chinese Patients With Hypertrophic Cardiomyopathy

Accurate identification of hypertrophic cardiomyopathy (HCM) patients at high risk of sudden cardiac death (SCD) event is challenging. The objective of this study was to validate the three SCD risk stratifications recommended by the 2014 European Society of Cardiology (ESC) guideline, the 2020 American Heart Association /American College of Cardiology (AHA/ACC) guideline, and the 2022 ESC guideline in Chinese patients with HCM. Our study population are made up of a cohort of 856 HCM patients without prior SCD events. The endpoint was defined as SCD or equivalent events (successful resuscitation after cardiac arrest or appropriate ICD shock for ventricular tachycardia or ventricular fibrillation). During a median follow-up of 43 months, SCD endpoints occurred in 44 (5.1%) patients. A total of 34 (77.3%) patients suffering from SCD events were classified correctly into high-risk groups by the 2020 AHA/ACC guideline, 27(61.4%) by the 2022 ESC guideline, and 13 (29.6%) by the 2014 ESC guideline. The C-statistic of the 2020 AHA/ACC guideline was 0.68 (95% CI, 0.60-0.76), which performed better than the 2022 ESC guideline (0.65: 95% CI, 0.56-0.73), and the 2014 ESC guideline (0.58: 95% CI, 0.48-0.67). The 2020 AHA/ACC guideline displayed better discrimination for SCD risk stratification in Chinese HCM patients than the other two guidelines, with a higher sensitivity but lower specificity.

Cardiac defibrillator implantation in patients with syncope and inducible ventricular arrhythmia: insights from the German DEVICE registry

Abstract Funding Acknowledgements Type of funding sources: None. Background Programmed ventricular stimulation may be considered for risk stratification of sudden cardiac death. The history of syncope is an independent predictor for appropriate device discharge and sudden cardiac death, but data remain sparse among different populations. Purpose The aim of this study was to assess the prognostic value of previous syncope and inducible ventricular arrhythmia (VA) during programmed stimulation in patients undergoing defibrillator implantation. Methods Among 4,196 patients enrolled in the prospective, multi-centre German DEVICE Registry undergoing defibrillator implantation, patients with syncope and inducible VA (n=285, 6.8%) vs. those with a secondary preventive indication (n=1,885, 45.2%) serving as a control group were studied. In an additional analysis of patients with inducible VA, those with vs. without (n=86, 2.1%) previous syncope were compared. Results Patients with syncope and inducible VA (64.9±14.4 years, 81.1% male) presented less often with congestive heart failure (15.1% vs. 29.1%; P&amp;lt;0.001) and any underlying structural heart disease (84.9% vs. 89.3%; P=0.030) with a higher left ventricular ejection fraction (43.7±14.2% vs. 38.1±14.2%; P&amp;lt;0.001) than patients with a secondary preventive indication (65.0±13.8 years, 81.0% male). Whereas dilated cardiomyopathy (16.8% vs. 23.8%; P=0.009) was less common in patients with syncope and inducible VA, hypertrophic cardiomyopathy (5.6% vs. 2.8%; P=0.010) and Brugada syndrome (2.1% vs. 0.3%; P&amp;lt;0.001) were found more frequently. Device implantation was performed more often urgently in patients with syncope and inducible VA (46.4% vs. 22.5%; P=0.005). During 1 year of follow-up, mortality (5.1% vs. 8.9%; P=0.036) and the rate of major adverse cardiac or cerebrovascular events (5.8% vs. 10.0%; P=0.027) were lower in patients with previous syncope and inducible VA compared to patients with a secondary preventive indication. Among patients with inducible VA, post-procedural adverse events including rehospitalization (27.6% vs. 21.7%; P=0.37), defibrillator shocks (16.0% vs. 15.0%; P=0.85) and recurrent syncope (3.0% vs. 0%; P=0.32) did not differ between those with vs. without syncope. Conclusions Patients with a history of syncope and inducible VA present less frequently with most cardiac comorbidities resulting in better outcomes following defibrillator implantation than patients with a secondary preventive indication. Nevertheless, patients with inducible VA experience a relevant number of post-procedural adverse events not differing between those with vs. without syncope, which underlines the importance of VA inducibility, potentially irrespective of the history of syncope.

Using the 3D architecture of scar to predict life-threatening ventricular arrythmias - still a long way to go

Abstract Funding Acknowledgements Type of funding sources: None. Background Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias. Purpose The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD). Methods We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 5 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock) or SCD. Results A total of 75 patients were analysed (mean age 63 ± 13 years; 83% male; mean LVEF 31 ± 13%; 50 patients with ischemic and 25 with non-ischemic cardiomyopathy; 14 patients received a device in the setting of secondary prevention). During a median follow-up of 1.4 years (IQR 0.7 – 2.4 years) there were 15 events (12 appropriate ICD therapies [8 shocks and 4 ATP] and 3 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values &amp;gt; 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 11 patients did not show any channel. Two of these experienced an arrhythmic event, yielding a negative predictive value of 80% (95% CI 75-83%) for the absence of channels. Conclusion In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.

Resting heart rate does not refine risk stratification of sudden cardiac death in the general population

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020 Background Sudden cardiac death (SCD) is a major public health issue in which most events occur in the general population. Although resting heart rate is associated with SCD, its added value regarding prediction is unknown. Methods for risk stratification and prediction are needed to help prevent future SCD. Purpose The aim of this study was to assess the association between resting heart rate (RHR) and SCD in the general population. Methods Participants from the Copenhagen City Heart Study in sinus rhythm with baseline RHR between 40 and 120 bpm were followed from 1993 to 2016. Deaths were adjudicated, by two cardiologists, using death certificates and autopsy reports. Associations between RHR and SCD was investigated using cause specific cox models. The added value of RHR in predicting SCD was investigated by adding RHR to an already published prediction model (including age, sex, cholesterol, statin use, hypertension, systolic and diastolic blood pressure, current smoking status, diabetes, and body mass index (Bogle 2018)). RHR was evaluated as a continuous covariate with a linear effect. Prediction performance measures were evaluated using bootstrap cross validation. Results The study included 10,099 participants of which 8,986 fulfilled inclusion criteria (median age 60 (25%-75%: 47-70), 57% female). During 24 years of follow-up 4,668 deaths including 656 SCD were observed. Mean RHR was 73 bpm (SD 12.4). Increasing HR was associated with incidence of SCD (HR 1.18 (95% CI: 1.12-1.26) per 10 bmp), however, almost to the same extend with death from other causes (HR 1.14 (1.11-1.17). History of AMI and baseline hypertension were differentially associated with the two outcomes, but not RHR (figure 1). We find no added value when including RHR in a prediction model (AUC at 10 years 80.6 vs 80.4 (figure 2), Brier score 3.1 vs 3.1). Allowing for a more flexible RHR-fit (non-linear effect and interaction) did not improve predictions. All results were consistent in sensitivity analyses (only individuals &amp;lt;70 years at entry, censoring after 10 years of follow up, only the most certain SCD diagnoses). Conclusion In the general population, even if RHR was associated with SCD, it did not refine risk stratification when added to a model previously published.

The Prognostic Role of Programmed Ventricular Stimulation in the Risk Stratification of Sudden Cardiac Death.

Sudden cardiac death (SCD) is one of the leading causes of cardiovascular death in general population. SCD primary prevention requires the correct selection of patients at increased risk who may benefit from implantable cardioverter-defibrillator (ICD). Despite several non-invasive arrhythmic risk indexes are available, their ability to stratify the SCD risk among asymptomatic patients with cardiac disease at increased arrhythmic risk is debated. The programmed ventricular stimulation (PVS) is an invasive approach historically used for SCD risk stratification in patients with acquired or inherited cardiac disease and is currently included in international guidelines. Aim of this review is to summarize all available data about the role of PVS for the SCD risk stratification in different clinical settings.

Impact of fibrosis extend on multiparametric assessment for ventricular arrhythmias risk in non-ischemic dilated cardiomyopathy

The consensus guidelines recommended implantable cardioverter defibrillators (ICD) for sudden cardiac death prevention in patient with non-ischemic dilated cardiomyopathy (DCM) and LVEF < 35%. However, recent data suggest that it will not affect prognosis. Some markers have identified patients with higher risk of ventricular arrhythmias independently of LVEF. Better optimization of risk stratification for sudden cardiac death and specify implantation criteria are necessary. We performed comprehensive cardiac evaluation including imaging to predict ventricular arrhythmias in a population of non-ischemic DCM. We conducted a monocentric retrospective study including 107 patients with non-ischemic DCM and implanted with ICD as primary prevention from 2013 to 2019. Primary outcome is composite of appropriate therapy by ICD for ventricular tachycardia and ventricular fibrillation or sudden cardiac death. All-cause mortality and LVEF progress are secondary outcome. Primary outcome occurred in 21 patients (20%). In univariate analysis, GFR especially when it is < 50 mL.min-1.1.73 m-2(HR 4.62, P = 0.003), right ventricle ejection fraction under 40% (HR 2.48, p 0.04), number of segments with LGE (HR 1.22, P < 0.001) especially when there are 3 or more (HR 5.47, P < 0.001) or subepicardial location (HR 3.33, P = 0.03) are associated with ventricular arrhythmias. In a multiparametric assessment, this study highlights one important parameter associated with ventricular arrhythmias in selected population of non-ischemic DCM and LVEF < 35%: the extend of myocardial fibrosis, especially with 3 or more segments with LGE. It supports the concept of “critical mass” of fibrosis necessary for initiation and maintenance of ventricular arrhythmias. It was demonstrated in ischemic heart disease but a threshold value remains to be determined in non-ischemic DCM. The main result (Fig. 1).

PO-03-086 USING THE 3D ARCHITECTURE OF SCAR TO PREDICT LIFE-THREATENING VENTRICULAR ARRHYTHMIAS – STILL A LONG WAY TO GO

Late gadolinium enhancement (LGE) has been proposed as an independent predictor of ventricular arrhythmias. The purpose of this study was to assess if myocardial scar characterization could enhance the risk stratification for life-threatening arrhythmias and sudden cardiac death (SCD). We included patients with an indication for ICD or CRT-D implantation who underwent cardiac magnetic resonance for clinical proposes since February/2018 and in whom a 3D-LGE dataset was obtained. Patients with channelopathies (n=2) or inappropriate imaging quality (imaging artifacts; n=7) were excluded. Scar characterization using ADAS software was performed in 3D-LGE datasets in all but 16 patients, where 2D datasets were used. The primary endpoint was the composite of appropriate ICD therapy (classified as ATP or shock), sustained ventricular tachycardia or SCD. A total of 116 patients were analysed (mean age 66 ± 14 years; 81% male; mean LVEF 34 ± 14%; 74 patients with ischemic and 42 with non-ischemic cardiomyopathy; 40 patients received a device in the setting of secondary prevention). During a median follow-up of 2.3 years (IQR 1.3 – 3.3 years) there were 23 events (18 appropriate ICD therapies [9 shocks and 9 ATP], 3 episodes of VT under the threshold for ICD therapy and 2 SCD). No statistically significant differences were found between patients with or without events in terms of scar mass, border zone (BZ) mass, BZ channels (BZC), BZC mass, number of channels detected, and scar heterogeneity (BZ mass / scar mass ratio) - all p values > 0.2 – Figure. Restricting the analysis to only primary prevention cases yielded similar results. Overall, 26 patients did not show any channel. Four of these (all with non-ischemic LGE) experienced an arrhythmic event, yielding a negative predictive value of 83% (95% CI 64-93%) for the absence of channels. In this cohort with still relatively limited follow-up duration, no single parameter reflecting scar tissue characterization was able to predict appropriate device therapies or sudden cardiac death.

Performance of heart rate adjusted heart rate variability for risk stratification of sudden cardiac death

PurposeAs a non-invasive tool for the assessment of cardiovascular autonomic function, the predictive value of heart rate variability (HRV) for sudden cardiac death (SCD) risk stratification remains unclear. In this study, we investigated the performance of the individualized heart rate (HR) adjusted HRV (HRVI) for SCD risk stratification in subjects with diverse risks.MethodsA total of 11 commonly used HRV metrics were analyzed in 192 subjects, including 88 healthy controls (low risk group), 82 hypertrophic cardiomyopathy (HCM) patients (medium risk group), and 22 SCD victims (high risk group). The relationship between HRV metrics and HR was examined with long-term and short-term analysis. The performance HRVI was evaluated by area under the receiver operating characteristic curve (AUC) and covariance of variation (CV).ResultsMost of the HRV metrics were exponentially decayed with the increase of HR, while the exponential power coefficients were significantly different among groups. The HRVI metrics discriminated low, medium and high risk subjects with a median AUC of 0.72[0.11], which was considerably higher than that of the traditional long-term (0.63[0.04]) and short-term (0.58[0.05]) HRV without adjustment. The average CV of the HRVI metrics was also significantly lower than traditional short-term HRV metrics (0.09 ± 0.02 vs. 0.24 ± 0.13, p < 0.01).ConclusionsSubjects with diverse risks of SCD had similar exponential decay relationship between HRV metrics and HR, but with different decaying rates. HRVI provides reliable and robust estimation for risk stratification of SCD.

ESC-Leitlinie 2022: Management ventrikulärer Arrhythmien in der klinischen Praxis

The recently published guideline of the European Society of Cardiology for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death updates the guideline from 2015. Overall, the current guideline is characterised by a great practical relevance: Illustrative algorithms, e.g., for diagnostic evaluation, and tables make the guideline a user-friendly reference book. In the diagnostic evaluation and risk stratification of sudden cardiac death, cardiac magnetic resonance imaging and genetic testing are significantly upgraded. In long-term management, the optimal treatment of the underlying disease is essential, and recommendations for heart failure therapy are adapted to current international guidelines. Catheter ablation is upgraded especially for patients with ischaemic cardiomyopathy and recurrent ventricular tachycardia, as well as in the management of symptomatic idiopathic ventricular arrhythmias. Criteria for primary prophylactic defibrillator therapy remain controversial. In the context of dilated cardiomyopathy, imaging, genetic testing, and clinical factors are given special weight in addition to left ventricular function. Additionally, revised diagnostic criteria for a large number of primary electrical diseases are provided.

Conflicting results on the role of ECG in risk-stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy.

The research group at University College London introduced the concept of standardizing the quantification of risk by assessing risk of sudden death or equivalent malignant arrhythmia event occurring during the subsequent 5 years of follow-up after diagnosis. While the aims in the recent article by Norrish et al.1 published in this journal are laudable, it is imperative to highlight the methodological shortcomings underlying their analysis. The authors aim to assess the ability of the electrocardiogram (ECG) risk-score and other aspects of the 12-lead ECG to predict ‘major arrhythmic cardiac event’. They selected a subset (356/1029) of the multi-centre cohort of paediatric patients with hypertrophic cardiomyopathy (HCM) used to construct the HCM Risk-Kids algorithm, where ECGs had been archived. This subset however consisted mainly of recently recruited patients, and so median follow-up was only 3.9 years (interquartile range Q1–Q3 2.0–7.7).1 A major concern is that Norrish et al. did not restrict their analysis to include only those survivors who had reached 5 years of follow-up (n = 77 + 68 = 145), and the patients who had a ‘major arrhythmic cardiac event’ within 5 years of follow-up (n = 17). Instead they compared all patients without events, even if 25% of them had <2 years follow-up, with all patients who had major arrhythmic cardiac event, even if 8 of them had an event later than 5 years of follow-up. Thus, in fact, only 17 (patients with major arrhythmic cardiac event within 5 years) + 145 (patients with ≥5 years follow-up without event) = 162 of the patients are actually statistically informative about the end-point of major arrhythmic cardiac event within 5 years.1 This constitutes only 46% of the total ECG group analysed. The other 194 actually confuse the results as patients with high-risk ECG features and short follow-up might have had a major arrhythmic cardiac event later on within the 5-year span. Similarly, the ECGs of patients with major arrhythmic cardiac event after >5 years of follow-up might have evolved more ECG changes closer to the event as shown in other studies.2 Thus including these late major arrhythmic cardiac events will underestimate the sensitivity of the method.