Predictive value of a comprehensive atrial assessment with cardiac magnetic resonance in non-ischemic cardiomyopathy: keep it simple

Cardiac magnetic resonance (CMR) can provide a multi-parametric evaluation of left atrial (LA) size and function. A complete CMR-based LA assessment might improve the risk stratification of patients with non-ischemic dilated cardiomyopathy (DCM). We performed a comprehensive CMR-based evaluation of LA size and function, in order to assess the prognostic impact of specific LA parameters in DCM. Secondary analysis of a prospective registry (UHSM-CMR study, NCT02326324) including 648 consecutive patients with DCM and CMR evaluation of LA area and LA length. Of these, 456 had complete LA assessment covering reservoir, conduit and booster pump function and including LA reservoir strain evaluated with feature tracking. The heart failure (HF) endpoint included HF hospitalizations, HF death and heart transplant. The arrhythmic endpoint included ventricular arrhythmias (VA) (sustained or treated by implantable defibrillator) and sudden death (SD). At median follow-up of 23 months, 34 patients reached the HF endpoint; in a multivariable model including NYHA class and LVEF, LA length had incremental predictive value. LA length ≥ 69 mm was the best cut-off to predict HF events (adjusted HR 2.3, p = 0.03). Among the 456 patients with comprehensive LA assessment, only LA length was independently associated with the HF endpoint after adjusting for LVEF and NYHA class. By contrast, no LA parameter independently predicted the arrhythmic risk. In DCM patients, LA length is an independent predictor of HF events, showing stronger association than other more complex parameters of LA function. No atrial parameter predicts the risk of VA and SD.

Impact of Cardiac Magnetic Resonance to Arrhythmic Risk Stratification in Nonischemic Cardiomyopathy

Left ventricular ejection fraction-based arrhythmic risk stratification in nonischemic cardiomyopathy (NICM) is insufficient and has led to the failure of primary prevention implantable cardioverter defibrillator trials, mainly due to the inability of selecting patients at high risk for sudden cardiac death (SCD). Cardiac magnetic resonance offers unique opportunities for tissue characterization and has gained a central role in arrhythmic risk stratification in NICM. The presence of myocardial scar, denoted by late gadolinium enhancement, is a significant, independent, and strong predictor of ventricular arrhythmias and SCD with high negative predictive value. T1 maps and extracellular volume fraction, which are able to quantify diffuse fibrosis, hold promise as complementary tools but need confirmatory results from large studies.

Ventricular Electrograms Duration Map to Detect Ventricular Arrhythmia Substrate: the VEDUM Project Study

BACKGROUND

The analysis of the wave-front activation patterns is crucial for the comprehension and treatment of ventricular tachycardia (VT). The ventricular electrograms duration map (VEDUM) is a potential method to identify areas (VEDUM area) with slow and inhomogeneous activation. There is no available data on the characteristics and the arrhythmogenic role of VEDUM areas identified during sinus/paced rhythm.

METHODS

Patients referred for VT ablation were enrolled at 3 different centers. VEDUM maps during sinus/paced rhythm as well as substrate and functional maps were created; activation mapping was performed for all hemodynamically tolerated VT.

RESULTS

Thirty-two patients (mean age:70.1±9.4 years; males 93.8%) were enrolled. The VEDUM approach was achieved in all patients and the mean size of the VEDUM area was 12.1±6.9 cm2 (interquartile range, 7.8-14.9 cm2). A significative difference was observed between the electrogram duration in the VEDUM area and the normal tissue (163.7 ms [interquartile range, 142.3-199.2 ms]; versus 65.5 ms [interquartile range, 59.5-76.2 ms]; P<0.001). The VEDUM area was visualized in a dense scar (<0.5 mV) in 19 (59.4%) patients. A deceleration zone and late potentials were recorded inside the VEDUM area in 56.3% and 81.3%, respectively. When a complete VT activation mapping was available, the isthmus projected in the VEDUM area in 93.5% of patients; 8 of them had multiple VTs mapped and in the 87.5% all VT isthmuses were included in the VEDUM area.

CONCLUSIONS

VEDUM maps allow the identification of discrete areas of inhomogeneous and slow conduction. They represent a potential target for VT ablation, including patients with multiple morphologies.

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole

AIMS

To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min…<1 h, 1 h…<24 h, ≥ 24 h). We used the MATRIX registry data to assess the capability of a single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (DX ICD system) to follow this recommendation in patients with standard indication for single-chamber ICD.

METHODS AND RESULTS

In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min…<1 h, 99.6% (253/254) for episodes 1 h…<24 h, 100% (71/71) for episodes ≥24 h, or 97.5% for all episodes (595/610). The incidence of new-onset AF was 8.2% (119/1451), and in 31.1% of them (37/119), new-onset AF progressed to a higher duration stratum. Nearly 80% of new-onset AF patients had high CHA2DS2-VASc stroke risk, and 70% were not on anticoagulation therapy. Age was the only significant predictor of new-onset AF.

CONCLUSION

A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Late gadolinium enhancement and the risk of ventricular arrhythmias and sudden death in NYHA class I patients with non-ischaemic cardiomyopathy

AIM

To compare the risk of ventricular arrhythmias (VA) and sudden death (SD) between New York Heart Association (NYHA) class I and NYHA class II-III patients with non-ischaemic cardiomyopathy (NICM).

METHODS AND RESULTS

Observational retrospective cohort study including patients with NICM who underwent cardiac magnetic resonance at two hospitals. The primary endpoint included appropriate implantable cardioverter defibrillator (ICD) therapies, sustained ventricular tachycardia, resuscitated cardiac arrest and SD. The secondary endpoint included heart failure (HF) hospitalizations, heart transplant, left ventricular assist device implant or HF death. Overall, 698 patients were included, 33% in NYHA class I. During a median follow-up of 31 months, the primary endpoint occurred in 57 patients (8%), with no differences between NYHA class I and NYHA class II-III cases (7% vs. 9%, p = 0.62). Late gadolinium enhancement (LGE) was the only independent predictor of the primary outcome both in NYHA class I and NYHA class II-III patients. LGE+ NYHA class I patients had a similar cumulative incidence of the primary endpoint as compared to LGE+ NYHA class II-III (p = 0.92) and a significantly higher risk as compared to LGE- NYHA class II-III cases (p < 0.001). The risk of the secondary endpoint was significantly higher in patients in NYHA class II-III as compared to those in NYHA class I (hazard ratio 3.2, p = 0.001).

CONCLUSIONS

Patients with NICM in NYHA class I are not necessarily at low risk of VA and SD. Actually, LGE+ NYHA class I patients have a high risk. NYHA class I patients with high-risk factors, such as LGE, could benefit from primary prevention ICD at least as much as those in NYHA class II-III with the same risk factors.

Extracellular volume fraction improves risk-stratification for ventricular arrhythmias and sudden death in non-ischaemic cardiomyopathy

AIMS

To evaluate whether cardiac magnetic resonance (CMR)-based parametric mapping and strain analysis can improve the risk-stratification for ventricular arrhythmias (VA) and sudden death (SD) in non-ischaemic cardiomyopathy (NICM).

METHODS AND RESULTS

Secondary analysis of a prospective single-centre-registry (NCT02326324), including 703 consecutive NICM patients, 618 with extracellular volume (ECV) available. The combined primary endpoint included appropriate implantable cardioverter defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest and SD. During a median follow-up of 21 months, 14 patients (2%) experienced the primary endpoint. Native T1 was not associated with the primary endpoint. Left ventricular global longitudinal strain lost its significant association after adjustment for left ventricular ejection fraction (LVEF). Among patients with ECV available, 11 (2%) reached the primary endpoint. Mean ECV was significantly associated with the primary endpoint and the best cut-off was 30%. ECV ≥ 30% was the strongest independent predictor of the primary endpoint (hazard ratio 14.1, P = 0.01) after adjustment for late gadolinium enhancement (LGE) and LVEF. ECV ≥ 30% discriminated the arrhythmic risk among LGE+ cases and among those with LVEF ≤ 35%. A simple clinical risk-stratification model, based on LGE, LVEF ≤ 35% and ECV ≥ 30%, achieved an excellent predictive ability (Harrell's C 0.82) and reclassified the risk of 32% of the study population as compared to LVEF ≤ 35% alone.

CONCLUSIONS

Comprehensive CMR evaluation in NICM showed that ECV was the only parameter with an independent and strong predictive value for VA/SD, on top of LGE and LVEF. A risk-stratification model based on LGE, LVEF ≤ 35% and ECV ≥ 30% achieved an excellent predictive ability for VA/SD.

CLINICAL TRIAL REGISTRATION

UHSM CMR study (NCT02326324) https://clinicaltrials.gov/ct2/show/NCT02326324.

Prognostic impact of late gadolinium enhancement at the right ventricular insertion points in non-ischaemic dilated cardiomyopathy

AIMS

To evaluate the baseline characteristics and the prognostic implications associated with late gadolinium enhancement limited to the right ventricular insertion points (IP-LGE) or present at both the right ventricular insertion points and the left ventricle (IP&LV-LGE) in non-ischaemic dilated cardiomyopathy (DCM).

METHODS AND RESULTS

This is a retrospective observational multicentre cohort study including 1165 consecutive patients with DCM evaluated by cardiac magnetic resonance. The primary endpoint included appropriate defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest, or sudden death. The secondary outcome encompassed heart failure hospitalizations, heart transplant, left ventricular assist device implantation, and end-stage heart failure death. IP-LGE was found in 72 patients (6%), who had clinical characteristics closer to LGE- than to LGE+ patients. During follow-up (median 36 months), none of the IP-LGE patients experienced the primary endpoint. The cumulative incidence of the primary endpoint was similar between IP-LGE and LGE- patients (P = 1), while IP-LGE had significantly lower cumulative incidence when compared with LGE+ patients (P < 0.001). When compared with IP-LGE patients, the cumulative incidence of the secondary endpoint was similar in LGE- cases (P = 0.86) but tended to be higher in LGE+ patients (P = 0.06). Both clinical characteristics and outcomes were similar between IP&LV-LGE patients and the rest of LGE+ cases.

CONCLUSIONS

In a large cohort of DCM patients, IP-LGE was associated with similar outcome when compared with LGE- patients and with significant lower risk of ventricular arrhythmias and sudden death when compared with LGE+ cases. Patients with IP&LV-LGE had clinical characteristics and outcomes similar to the rest of LGE+ cases.

[Spanish catheter ablation registry. 21st official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021)]

Introduction and objectives

The results of the 2021 Spanish catheter ablation registry are presented.

Methods

Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers.

Results

Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193 ± 133 clases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%).

Conclusions

The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.

Distinct spectral dynamics of implanted cardiac defibrillator signals in spontaneous termination of polymorphic ventricular tachycardia and fibrillation in patients with electrical and structural diseases

AIMS

To determine the spectral dynamics of early spontaneous polymorphic ventricular tachycardia and ventricular fibrillation (PVT/VF) in humans.

METHODS AND RESULTS

Fifty-eight self-terminated and 173 shock-terminated episodes of spontaneously initiated PVT/VF recorded by Medtronic implanted cardiac defibrillators (ICDs) in 87 patients with various cardiac pathologies were analyzed by short fast Fourier transform of shifting segments to determine the dynamics of dominant frequency (DF) and regularity index (RI). The progression in the intensity of DF and RI accumulations further quantified the time course of spectral characteristics of the episodes. Episodes of self-terminated PVT/VF lasted 8.6 s [95% confidence interval (CI): 8.1-9.1] and shock-terminated lasted 13.9 s (13.6-14.3) (P < 0.001). Recordings from patients with primarily electrical pathologies displayed higher DF and RI values than those from patients with primarily structural pathologies (P < 0.05) independently of ventricular function or antiarrhythmic drug therapy. Regardless of the underlying pathology, the average DF and RI intensities were lower in self-terminated than shock-terminated episodes [DF: 3.67 (4.04-4.58) vs. 4.32 (3.46-3.93) Hz, P < 0.001; RI: 0.53 (0.48-0.56) vs. 0.63 (0.60-0.65), P < 0.001]. In a multivariate analysis controlled by the type of pathology and clinical variables, regularity remained an independent predictor of self-termination [hazard ratio: 0.954 (0.928-0.980)]. Receiver operating characteristic (ROC) curve analysis of DF and RI intensities demonstrated increased predictability for self-termination in time with 95% CI above the 0.5 cut-off limit at about t = 8.6 s and t = 6.95 s, respectively.

CONCLUSION

Consistent with the notion that fast organized sources maintain PVT/VF in humans, reduction of frequency and regularity correlates with early self-termination. Our findings might help generate ICD methods aiming to reduce inappropriate shock deliveries.

Registro español de ablación con catéter. XXI Informe oficial de la Asociación del Ritmo Cardiaco de la Sociedad Española de Cardiología (2021)

Introduction and objectives

The results of the 2021 Spanish catheter ablation registry are presented.

Methods

Data collection was carried out retrospectively by filling in and sending a specific form by the participating centers.

Results

Data from 93 centers (65 public, 28 private) were analyzed. A total of 17941 ablation procedures were reported with a mean of 193 ± 133 cases per centre. Recovery of activity from SARS-CoV-2 pandemic lockdown has led to a notable increase in the number of procedures (+2772 procedures, +18%) despite a small decrease in participating centers (4 centers less than in 2020). Atrial fibrillation ablation continues to be the leading procedure, with 5848 procedures (32,6%). Together with ablation of the cavotricuspid isthmus (3766; 21%) and atrioventricular nodal reentrant tachycardia (3132; 17,5%) they constitute the 3 most frequently approached substrates. The total success rate reported (94%) is similar to previous years with a similar rate of complications (2%) and mortality (0.07). A total of 401 procedures were performed in pediatric patients (3,8%).

Conclusions

The Spanish catheter ablation registry systematically and continuously collects the national activity, which has recovered significantly from the SARS-CoV-2 pandemic impact in 2020. Success rate for 2021 remains high, with a low complication rate.

Ventricular Arrhythmias and Sudden Death in Nonischemic Dilated Cardiomyopathy: Matter of Sex or Scar?

BACKGROUND

To evaluate the association between sex and ventricular arrhythmias (VA) or sudden death (SD) in nonischemic dilated cardiomyopathy, including analysis of potential confounders.

METHODS AND RESULTS

Retrospective cohort study of consecutive patients with DCM referred for cardiac magnetic resonance at 2 tertiary hospitals. The primary combined end point encompassed sustained VA, appropriate implantable cardioverter defibrillator therapies, resuscitated cardiac arrest, and SD. We included 1165 patients with median follow-up of 36 months (interquartile range 20-58 months). The majority of patients (66%) were males. Males and females had similar left ventricular ejection fraction, but the prevalence of late gadolinium enhancement (LGE) at cardiac magnetic resonance was significantly higher among males (48% vs 30%, P < .001). Males had higher cumulative incidence of the primary end point (8% vs 4%, P = .02), and male sex was a significant predictor of the primary end point at univariate analysis (hazard ratio 1.93, P = .02). However, LGE had a major confounding effect in the association between sex and the primary outcome: the hazard ratio of male sex adjusted for LGE was 1.29 (P = .37). LGE+ females had significantly higher cumulative incidence of the primary end point than LGE- males (13% vs 1.8%, P < .001).

CONCLUSIONS

In patients with DCM, the prevalence of LGE is significantly higher among males, implying a major confounding effect in the association between male sex and VA or SD. LGE+ females have significantly higher risk than LGE- males. These data do not support the inclusion of sex into risk stratification algorithms for VA or SD in DCM.

Real-world experience on implantation and atrial signal detection of a SC ICD with atrial sensing capability: The MATRIX study

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIK, Berlin, Germany

Introduction

A single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (the DX ICD system) can potentially give additive information concerning atrial diagnostics in patients requiring only a single-chamber ICD. We therefore report the real-world experience from large DX registry on implantation, atrial signal quality and detection and the long-term stability of the atrial signal.

Methods

The prospective, single-arm MATRIX (Management and Detection of Atrial Tachyarrhythmias in Patients Implanted With BIOTRONIK DX Systems, NCT01774357) registry study effectively enrolled 2041 patients at 119 sites in 24 countries. All patients had a DX system implanted for a single-chamber ICD indication for primary or secondary prevention of sudden cardiac death. Patients were followed for 24 months including remote monitoring. Implantation and follow-up data are reported for the whole patient set. For the analyses on atrial sensing amplitude values, remotely transmitted device measurements of patients without history of long-standing persistent or permanent AF at baseline were used.

Results

The mean follow-up period was 677±173 days. Implantation took place at 15±22 days before enrollment. Baseline and implantation data are shown in the table. Implantation procedure and lead insertion were rated as "easy" or "very easy" in 91.0% and 96.3% of assessments, respectively. At implantation, the investigators rated the quality of the atrial sensing amplitude as "sufficient" in 97% of the assessed cases. At enrollment (12-month/24-month follow-up), the atrial signal quality and detection were rated as "good" or "excellent" in 92.3% (89.8%/89.9%) and 92.4% (90.1%/91.3%) of assessments, respectively. For 1841 patients (90.2%), remotely transmitted device information was received. The median (mean ± SD, IQR) transmission rate was 92.5% (85.4±18.2%, 81.4-97.3%). 1746 patients (85.5%) matched the inclusion criteria for the quantitative analyses on atrial sensing. 95.6% of available RA sensing amplitude values were ≥1 mV. Based on each patient’s overall median value, the median (mean ± SD, IQR) RA sensing amplitude was 4.6 mV (4.4±2.0 mV, 2.8-6.2 mV). The time course of patient median values stratified by month is shown in the figure.

Conclusion

The study followed 2041 patients implanted with the DX ICD system for two years. In the vast majority of cases, investigators rated implantation as (very) easy and the atrial signal over 24 months as good/excellent. According to daily, automatic Home Monitoring data, the overall mean P-wave amplitude remained stable throughout the whole follow-up. The MATRIX study demonstrated functionality and clinical utility of the DX concept in an unselected, real-life setting.

Improved prediction of electrical storm in patients with prior myocardial infarction and implantaImproved prediction of electrical storm in patients with prior myocardiable cardioverter defibrillator

Funding Acknowledgements

Type of funding sources: None.

Aims

To evaluate predictors of electrical storm (ES), including chronic total occlusion in an infarct-related coronary artery (infarct-related artery CTO, IRACTO), in a cohort of patients with prior myocardial infarction (MI) and implantable cardioverter-defibrillators (ICD).

Methods

Multicenter observational cohort study including 643 consecutive patients with prior MI and a first ICD implanted between 2005 and 2018 at three tertiary hospitals. All the patients included in the study had undergone a diagnostic coronary angiography before ICD implantation. The variable prior ventricular arrhythmias (VA+) was positive in patients with secondary prevention ICDs and in those with at least one appropriate ICD therapy after primary prevention implantation.

Results

During a median follow-up of 42 months 59 patients (9%) suffered ES. The presence of at least one IRACTO not revascularized (IRACTO-NR) was associated with a significantly higher cumulative incidence of ES (14.5% vs 4.8%, p&lt;0.001). IRACTO-NR maintained a significant association with ES after adjustment for potential confounders (HR 2.3, p=0.005) and was an independent predictor of ES together with VA+ and LVEF. The best cut-off of LVEF to predict ES was ≤38%. A risk-prediction model based on IRACTO-NR, VA+ and LVEF≤38% identified three categories of ES risk (low, intermediate and high), with progressively increasing cumulative incidence of ES (2.2%, 9% and 20%).

Conclusion

In a cohort of patients with prior MI and ICD, IRACTO-NR is an independent predictor of ES. A new risk-prediction model allowed the identification of three categories of risk, with potentially important clinical implications.

Capability of guideline-conform remote atrial high rate episode monitoring with a single-chamber implantable defibrillator with atrial sensing

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIK, Berlin, Germany

Introduction

Device-detected atrial high-rate episodes (AHRE) and their burden progression are associated with an increased risk for thromboembolic events in correlation with CHA2DS2-VASc score and AHRE burden. To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend the monitoring of AHRE progression along pre-specified strata (6min…&lt;1h, 1h…&lt;24, ≥24h). We sought to assess the capability of a single-lead implantable cardioverter defibrillator (ICD), that is equipped with an atrial dipole for atrial sensing, to remotely detect and monitor AHRE burden progression in patients with standard indication to single-chamber ICD.

Methods

From the MATRIX (Management and Detection of Atrial Tachyarrhythmias in Patients Implanted With BIOTRONIK DX Systems) registry, we analyzed remotely transmitted, and electrogram (IEGM) AHREs in a subset of patients with remote transmissions and without history of long-standing AF at baseline. For each patient, we selected the first occurring episode per duration stratum and the first subsequent occurrence when progressing to a stratum of any longer duration. After episode adjudication by an independent electrophysiologist, we assessed the classification performance of the device (positive predictive value [PPV]) and analyzed AHRE onset and progression pathways.

Results

Of the MATRIX cohort, 1,746 patients matched the inclusions criteria (see table for patient characteristics) and 1,451 had no AF history. Of the 258 patients with AHREs (14.8%), 450 out of 465 evaluated episodes were correctly classified as AHRE. Reasons for misclassification were artifact (13) and R-wave oversensing (2). PPV was 96.8% (95% confidence interval 94.7%-98.2%). Grouped by stratum, PPV was 93.9%, 99.5% and 100% for 6min…&lt;1h, 1h…&lt;24 and ≥24h, respectively. Ninety six of 240 patients (40.0%) with a first episode according to the pre-specified strata were progressing to a stratum of longer duration and 9 patients (3.8%) had further progression (see Figure). In 119 out of 1,451 patients without AF history (8.2%), the device detected AHRE and 81 of them (4.6% of analysis set) had a mid to high risk for stroke and were not on anticoagulation therapy. In 121 out of 295 patients with known history of paroxysmal and persistent AF (41.0%), the arrhythmia was confirmed by the device.

Discussion and Conclusion: The single-chamber ICD with atrial sensing capabilities correctly classified ≈97% of all adjudicated AHREs ≥6min. About 7% of patients had device-detected AHRE onset and/or progression and a mid to high stroke risk. These patients would potentially benefit the most from a guideline-conform AF monitoring strategy to timely initiate anticoagulation medication for stroke prevention.

Improved prediction of electrical storm in patients with prior myocardial infarction and implantable cardioverter defibrillator

AIMS

To evaluate predictors of electrical storm (ES), including chronic total occlusion in an infarct-related coronary artery (infarct-related artery CTO, IRACTO), in a cohort of patients with prior myocardial infarction (MI) and implantable cardioverter-defibrillators (ICD).

METHODS

Multicenter observational cohort study including 643 consecutive patients with prior MI and a first ICD implanted between 2005 and 2018 at three tertiary hospitals. All the patients included in the study had undergone a diagnostic coronary angiography before ICD implantation. The variable prior ventricular arrhythmias (VA+) was positive in patients with secondary prevention ICDs and in those with at least one appropriate ICD therapy after primary prevention implantation.

RESULTS

During a median follow-up of 42 months 59 patients (9%) suffered ES. The presence of at least one IRACTO not revascularized (IRACTO-NR) was associated with a significantly higher cumulative incidence of ES (14.5% vs 4.8%, p < 0.001). IRACTO-NR maintained a significant association with ES after adjustment for potential confounders (HR 2.3, p = 0.005) and was an independent predictor of ES together with VA+ and LVEF. The best cut-off of LVEF to predict ES was ≤38%. A risk-prediction model based on IRACTO-NR, VA+ and LVEF≤38% identified three categories of ES risk (low, intermediate and high), with progressively increasing cumulative incidence of ES (2.2%, 9% and 20%).

CONCLUSION

In a cohort of patients with prior MI and ICD, IRACTO-NR is an independent predictor of ES. A new risk-prediction model allowed the identification of three categories of risk, with potentially important clinical implications.

Impact of lockdown during COVID-19 pandemic on physical activity and arrhythmia burden in heart failure patients

BACKGROUND

Restricted outdoor activity during COVID-19 related lockdown may accelerate heart failure (HF) progression and thereby increase cardiac arrhythmias. We analyzed the impact of March/April 2020 lockdown on physical activity and arrhythmia burden in HF patients treated with cardiac resynchronization therapy (CRT) devices with daily, automatic remote monitoring (RM) function.

METHODS

The study cohort included 405 HF patients enrolled in Observation of Clinical Routine Care for Heart Failure Patients Implanted with BIOTRONIK CRT Devices (BIO|STREAM.HF) registry in 16 countries, who had left ventricular ejection fraction (LVEF) ≤40% (mean 28.2 ± 6.6%) and NYHA class II/III/IV (47.9%/49.6%/2.5%) before CRT pacemaker/defibrillator implantation. The analyzed RM data comprised physical activity detected by accelerometer, mean heart rate and nocturnal rate, PP variability, percentage of biventricular pacing, atrial high rate episode (AHRE) burden, ventricular extrasystoles and tachyarrhythmias, defibrillator shocks, and number of implant interrogations (i.e., follow-ups). Intraindividual differences in RM parameters before (4-week period) versus during (4-week period) lockdown were tested for statistical significance and independent predictors were identified.

RESULTS

There was a significant relative change in activity (mean -6.5%, p < .001), AHRE burden (+17%, p = .013), and follow-up rate (-75%, p < .001) during lockdown, with no significant changes in other RM parameters. Activity decreased by ≥8 min/day in 46.5% of patients; predictors were higher LVEF, lower NYHA class, no defibrillator indication, and more activity before lockdown. AHRE burden increased by ≥17 min/day in 4.7% of patients; predictors were history of atrial fibrillation, higher LVEF, higher body mass index, and activity decrease during lockdown.

CONCLUSION

Unfavorable changes in physical activity, AHRE burden, and follow-up rate were observed during lockdown, but not in ventricular arrhythmia.

Personalized monitoring of electrical remodelling during atrial fibrillation progression via remote transmissions from implantable devices

Aims

Atrial electrical remodelling (AER) is a transitional period associated with the progression and long-term maintenance of atrial fibrillation (AF). We aimed to study the progression of AER in individual patients with implantable devices and AF episodes.

Methods and results

Observational multicentre study (51 centres) including 4618 patients with implantable cardioverter-defibrillator +/−resynchronization therapy (ICD/CRT-D) and 352 patients (2 centres) with pacemakers (median follow-up: 3.4 years). Atrial activation rate (AAR) was quantified as the frequency of the dominant peak in the signal spectrum of AF episodes with atrial bipolar electrograms. Patients with complete progression of AER, from paroxysmal AF episodes to electrically remodelled persistent AF, were used to depict patient-specific AER slopes. A total of 34 712 AF tracings from 830 patients (87 with pacemakers) were suitable for the study. Complete progression of AER was documented in 216 patients (16 with pacemakers). Patients with persistent AF after completion of AER showed ∼30% faster AAR than patients with paroxysmal AF. The slope of AAR changes during AF progression revealed patient-specific patterns that correlated with the time-to-completion of AER (R² = 0.85). Pacemaker patients were older than patients with ICD/CRT-Ds (78.3 vs. 67.2 year olds, respectively, P < 0.001) and had a shorter median time-to-completion of AER (24.9 vs. 93.5 days, respectively, P = 0.016). Remote transmissions in patients with ICD/CRT-D devices enabled the estimation of the time-to-completion of AER using the predicted slope of AAR changes from initiation to completion of electrical remodelling (R² = 0.45).

Conclusion

The AF progression shows patient-specific patterns of AER, which can be estimated using available remote-monitoring technology.

Ventricular arrhythmia risk is associated with myocardial scar but not with response to cardiac resynchronization therapy

AIMS

Sudden cardiac death (SCD) risk estimation in patients referred for cardiac resynchronization therapy (CRT) remains a challenge. By CRT-mediated improvement of left ventricular ejection fraction (LVEF), many patients loose indication for primary prevention implantable cardioverter-defibrillator (ICD). Increasing evidence shows the importance of myocardial scar for risk prediction. The aim of this study was to investigate the prognostic impact of myocardial scar depending on the echocardiographic response in patients undergoing CRT.

METHODS AND RESULTS

Patients with indication for CRT were prospectively enrolled. Decision about ICD or pacemaker implantation was based on clinical criteria. All patients underwent delayed-enhancement cardiac magnetic resonance imaging. Median follow-up duration was 45 (24-75) months. Primary outcome was a composite of sustained ventricular arrhythmia, appropriate ICD therapy, or SCD. A total of 218 patients with LVEF 25.5 ± 6.6% were analysed [158 (73%) male, 64.9 ± 10.7 years]. Myocardial scar was observed in 73 patients with ischaemic cardiomyopathy (ICM) (95% of ICM patients); in 62 with non-ischaemic cardiomyopathy (45% of these patients); and in all but 1 of 36 (17%) patients who reached the primary outcome. Myocardial scar was the only significant predictor of primary outcome [odds ratio 27.7 (3.8-202.7)], independent of echocardiographic CRT response. A total of 55 (25%) patients died from any cause or received heart transplant. For overall survival, only a combination of the absence of myocardial scar with CRT response was associated with favourable outcome.

CONCLUSION

Malignant arrhythmic events and SCD depend on the presence of myocardial scar but not on CRT response. All-cause mortality improved only with the combined absence of myocardial scar and CRT response.

Improved Risk Stratification for Ventricular Arrhythmias and Sudden Death in Patients With Nonischemic Dilated Cardiomyopathy

BACKGROUND

Risk stratification for ventricular arrhythmias (VA) and sudden death in nonischemic dilated cardiomyopathy (DCM) remains suboptimal.

OBJECTIVES

The goal of this study was to provide an improved risk stratification algorithm for VA and sudden death in DCM.

METHODS

This was a retrospective cohort study of consecutive patients with DCM who underwent cardiac magnetic resonance with late gadolinium enhancement (LGE) at 2 tertiary referral centers. The combined arrhythmic endpoint included appropriate implantable cardioverter-defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest, and sudden death.

RESULTS

In 1,165 patients with a median follow-up of 36 months, LGE was an independent and strong predictor of the arrhythmic endpoint (hazard ratio: 9.7; p < 0.001). This association was consistent across all strata of left ventricular ejection fraction (LVEF). Epicardial LGE, transmural LGE, and combined septal and free-wall LGE were all associated with heightened risk. A simple algorithm combining LGE and 3 LVEF strata (i.e., ≤20%, 21% to 35%, >35%) was significantly superior to LVEF with the 35% cutoff (Harrell's C statistic: 0.8 vs. 0.69; area under the curve: 0.82 vs. 0.7; p < 0.001) and reclassified the arrhythmic risk of 34% of patients with DCM. LGE-negative patients with LVEF 21% to 35% had low risk (annual event rate 0.7%), whereas those with high-risk LGE distributions and LVEF >35% had significantly higher risk (annual event rate 3%; p = 0.007).

CONCLUSIONS

In a large cohort of patients with DCM, LGE was found to be a significant, consistent, and strong predictor of VA or sudden death. Specific high-risk LGE distributions were identified. A new clinical algorithm integrating LGE and LVEF significantly improved the risk stratification for VA and sudden death, with relevant implications for implantable cardioverter-defibrillator allocation.

Impact of the Covid-19 related lockdown on physical activity, heart rate and arrhythmia burden in a large prospective cohort of CHF patients

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIK SE & Co. KG

OnBehalf

BIO|STREAM.HF

Background

At the beginning of the Covid-19 pandemic in spring 2020, governments around the world issued curfews and other stay at home orders (‘lockdown’) to limit the spread of the SARS-CoV19 virus. This may have forced people to decrease their physical activity. Physical inactivity as well as social stress is known to be especially deleterious for heart failure (HF) patients. The BIO|STREAM.HF study enrolled such HF patients into a prospective registry with Home Monitoring.

Purpose

We aimed to evaluate the impact of the lockdown during the first Covid-19 pandemic wave on physical activity and arrhythmia burden of heart failure patients.

Methods

We analysed daily transmitted data of patients enrolled into a large international registry (BIO|STREAM.HF) being implanted with a cardiac resynchronization therapy (CRT) devices. Patients with NYHA ≥ II and LVEF ≤ 40% before CRT implantation were selected.

Intra-individual weekly mean and median values were calculated for the following daily transmitted parameters: physical activity (measured as % of the day during which the patient moves), atrial arrhythmia burden, mean heart rate (at rest), PP variability, PVC burden, and rate of biventricular pacing. Values were calculated for 12 weeks before and 12 weeks after the country-specific effective date of most rigorous restrictions in spring 2020 to visualize the general trend of parameter changes. Moreover, values for intra-individual changes between three 28-days periods (before, during, and after the lockdown) were calculated.

Results

Of 444 patients, 76% were male. They had a mean age of 69 ± 10 years and LVEF of 28.2 ± 6.7%. HF was of ischemic etiology in 42% of cases and they were in NYHA class II (47.5%), III (50.0%) or IV (2.5%).

On average, patients were active for 9% of the day (2 h 10 min). The physical activity decreased by approx. 10% with the onset of the lockdown (figure 1) and recovered within the following eight weeks.

Comparison of the 28-days periods before, during and after the lockdown showed a statistically significant intra-individual decrease in physical activity (mean decrease 9 min per day) during the lockdown compared to pre- and post-lockdown values and a trend toward reduced mean heart rates. In parallel, a significant increase in device detected atrial arrhythmia burden (mean increase 17 min per day) was observed. All other parameters did not change significantly.

Conclusion 

Our results show that patients reduced their physical activity during the Covid-19 related lockdown in spring 2020. This was associated with an increase in atrial arrhythmia burden and a reduction of the mean heart rate. Prognostic implications of these results will further be analysed.

Long-Term Outcomes Among a Nationwide Cohort of Patients Using an Implantable Cardioverter-Defibrillator: UMBRELLA Study Final Results

Background

Large‐scale studies describing modern populations using an implantable cardioverter‐defibrillator (ICD) are lacking. We aimed to analyze the incidence of arrhythmia, device interventions, and mortality in a broad spectrum of real‐world ICD patients with different heart disorders.

Methods and Results

The UMBRELLA study is a prospective, multicenter, nationwide study of contemporary patients using an ICD followed up by remote monitoring, with a blinded review of arrhythmic episodes. From November 2005 to November 2017, 4296 patients were followed up. After 46.6±27.3 months, 16 067 episodes of sustained ventricular arrhythmia occurred in 1344 patients (31.3%). Appropriate ICD therapy occurred in 27.3% of study population. Patients with ischemic cardiomyopathy (hazard ratio [HR], 1.51; 95% CI, 1.29–1.78), dilated cardiomyopathy (HR, 1.28; 95% CI, 1.07–1.53), and valvular heart disease (HR, 1.94; 95% CI, 1.43–2.62) exhibited a higher risk of appropriate ICD therapies, whereas patients with hypertrophic cardiomyopathy (HR, 0.72; 95% CI, 0.54–0.96) and Brugada syndrome (HR, 0.25; 95% CI, 0.14–0.45) showed a lower risk. All‐cause death was 13.4% at follow‐up. Ischemic cardiomyopathy (HR, 3.09; 95% CI, 2.58–5.90), dilated cardiomyopathy (HR, 3.33; 95% CI, 2.18–5.10), and valvular heart disease (HR, 3.97; 95% CI, 2.25–6.99) had the worst prognoses. Delayed high‐rate detection was enabled in 39.7% of patients, and single‐zone programming occurred in 52.6% of primary prevention patients. Both parameters correlated with lower risk of first appropriate ICD therapy, with no excess risk of mortality. The rate of inappropriate shocks at follow‐up was low (6%) and did not differ among type of ICD but was lower in SmartShock‐capable devices.

Conclusions

Irrespective of the cause, contemporary ICD patients with heart failure–related disorders had a similar risk of ICD life‐saving interventions and death. Current ICD programming recommendations still need to be implemented.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NTC01561144.

Sex-Specific Ventricular Arrhythmias and Mortality in Cardiac Resynchronization Therapy Recipients

OBJECTIVES

The study goal was to examine whether there are sex-related differences in the incidence of ventricular arrhythmias and mortality in CRT-defibrillator (CRT-D) recipients.

BACKGROUND

Few studies have evaluated sex-related benefits of cardiac resynchronization therapy (CRT). Moreover, data on sex-related differences in the occurrence of ventricular tachyarrhythmias in this population are limited.

METHODS

A multicenter retrospective study was conducted in 460 patients (355 male subjects and 105 female subjects) from the UMBRELLA (Incidence of Arrhythmia in Spanish Population With a Medtronic Implantable Cardiac Defibrillator Implant) national registry. Patients were followed up through remote monitoring after the first implantation of a CRT-D during a median follow-up of 2.2 ± 1.0 years. Sex differences were analyzed in terms of ventricular arrhythmia-treated incidence and death during the follow-up period, with a particular focus on primary prevention patients.

RESULTS

Baseline New York Heart Association functional class was worse in women compared with that in men (67.0% of women in New York Heart Association functional class III vs. 49.7% of men; p = 0.003), whereas women had less ischemic cardiac disease (20.8% vs. 41.7%; p < 0.001). Female sex was an independent predictor of ventricular arrhythmias (hazard ratio: 0.40; 95% confidence interval: 0.19 to 0.86; p = 0.020), as well as left ventricular ejection fraction and nonischemic cardiomyopathy. Mortality in women was one-half that of men, although events were scarce and without significant differences (2.9% vs. 5.6%; p = 0.25).

CONCLUSIONS

Women with left bundle branch block and implanted CRT have a lower rate of ventricular tachyarrhythmias than men. All-cause mortality in patients is, at least, similar between female and male subjects.

Spanish Catheter Ablation Registry. 19th Official Report of the Heart Rhythm Association of the Spanish Society of Cardiology (2019)

INTRODUCTION AND OBJECTIVES

This report presents the findings of the 2019 Spanish Catheter Ablation Registry.

METHODS

Data collection was retrospective. A standardized questionnaire was filled by each of the participant centers.

RESULTS

Data sent by 102 centers were analyzed, with a total number of ablation procedures performed of 18549 (the highest historically reported in this registry) for a mean of 181.9±137.0 and a median of 144.5 procedures per center. The ablation targets most frequently treated were atrial fibrillation (n=5164; 27.8%), cavotricuspid isthmus (n=3925; 21.1%) and atrioventricular nodal reentrant tachycardia (n=3768; 20.3%). A new peak is observed in the ablation of atrial fibrillation, increasing the distance from the other substrates. The overall success rate was again 91%. The rate of major complications was 1.9%, and the mortality rate was 0.03%. An electroanatomic mapping system was used in 44.5% of all procedures, with contact force-sensing irrigated catheters become the preferred for complex substrates, as atrial fibrillation (84.8%) or ventricular tachycardia (around 90%). 1.5% of the ablations were performed in pediatric patients.

CONCLUSIONS

The Spanish Catheter Ablation Registry enrolls systematically and uninterruptedly the ablation procedures performed in Spain, showing a progressive increasing in the number of ablations over the years with a high success rate and low percentages of complications.

Impact of an adaptive CRT optimization algorithm on the risk of life-threatening ventricular arrythmias of heart failure patients

Introduction

Adaptive cardiac resynchronization therapy (aCRT) algorithm provides ambulatory CRT optimization and synchronized left-ventricular pacing instead of conventional biventricular pacing.

Purpose

To analyze the impact of aCRT on the risk of life-threatening ventricular arrythmia (VA) in patients with concomitant defibrillator therapy.

Methods

Symptomatic HF patients, in sinus rhythm, with LVEF ≤35% and QRS complex ≥130 ms undergoing first CRT-defibrillator (CRT-D) implant were collected from the multicentre, prospective and nationwide UMBRELLA study (2012–2017). All device information was automatically stored and collected through the remote monitoring system. An experts committee analysed in a blinded manner all electrograms. The endpoint was first appropriate therapy (AT) delivered within ventricular fibrillation zone at 12-months follow-up.

Results

206 patients were collected (66.1±8.7 years; 73.3% male). Fifty nine patients composed the aCRT group and 147 composed the non-aCRT group. At implant, LBBB was present in 93% of patients, functional class III or IV in 69.9%, non-ischemic HF in 63.1% of patients and mean LVEF was 26.5±5.6%. Optimal medical treatment was achieved in a majority (B-blockers in 92%; RAASi in 89% and MRA in 72.2%).

The percentage of ventricular pacing through 12 months was 96.1±9.4% in non-aCRT patients and 97.5±2.7% in aCRT patients (p=0.261). At 1-year of follow-up, 16 patients were delivered an AT (event rate: 7.8%). Most of these episodes (n=14) were due to sustained monomorphic ventricular tachycardia while the rest were caused by sustained polymorphic ventricular tachycardia/VF. A lower incidence of AT was observed in aCRT patients (3.4%) compared to non-aCRT patients (9.5%) but with no statistical differences (OR=0.33, CI 0.07–1.51, p=0.155).

Conclusions

In patients undergoing CRT provided by aCRT algorithm the risk of malign VA after 1-year of follow-up was low. Randomized studies are needed to clarify the impact of this dynamic algorithm on the arrhythmic risk of HF patients.

Funding Acknowledgement

Type of funding source: None

Genotype-phenotype correlation of LMNA variants involving the Arg541 residue: a case report with multimodality imaging and literature review

We present a case of atypical LMNA cardiomyopathy associated with the pathogenic variant p.Arg541Ser. The patient had early-onset severe ventricular arrhythmias but atrioventricular conduction was normal. Segmental motion abnormalities and a large transmural scar, mainly apical and lateral, were found at cardiac magnetic resonance, corresponding to areas of severe wall thinning at computed tomography and of low voltages at electroanatomic mapping. Ventricular tachycardia ablation was successful in controlling ventricular arrhythmias. Few other cases described patients with pathogenic variants in the Arg541 residue, and they displayed similar atypical features, suggesting a genotype-phenotype correlation which may have specific prognostic and therapeutic implications.

[Spanish Catheter Ablation Registry. 19th Official Report of the Heart Rhythm Association of the Spanish Society of Cardiology (2019)]

Introducción y objetivos

Se describen los resultados del Registro Español de Ablación correspondientes al año 2019.

Métodos

La recogida de datos ha sido retrospectiva mediante la cumplimentación de un formulario de recogida de datos por cada uno de los centros participantes.

Resultados

Se han analizado los datos enviados por 102 centros, con un total de 18.549 procedimientos de ablación (el mayor de este registro) y con una media de 181,9 ± 137,0 y una mediana de 144,5 procedimientos por centro. Se consolida la ablación de fibrilación auricular como el sustrato abordado con más frecuencia (n = 5.164; 27,8%), que aumenta la distancia respecto al resto de sustratos. El segundo sustrato es el istmo cavotricuspídeo (n = 3.925; 21,1%) y el tercero, la taquicardia por reentrada intranodular (n = 3.768; 20,3%), desbancada del segundo puesto por aquel. La tasa total de éxito fue de nuevo del 91%; la de complicaciones mayores, del 1,9% y la mortalidad, del 0,03%. Se consolida el uso de navegadores (el 44,5% del total de procedimientos) y de los catéteres con tecnología de contacto en la fibrilación auricular (84,8%) y la taquicardia ventricular (90%). El 1,5% de las ablaciones se realizaron en pacientes pediátricos.

Conclusiones

El Registro Español de Ablación recoge de manera sistemática sin interrupción los procedimientos de ablación realizados en España, y permite observar a lo largo de los años un aumento progresivo del número de ablaciones manteniendo una alta tasa de éxito y unos porcentajes bajos de complicaciones.

New Electrocardiographic Algorithm for the Diagnosis of Acute Myocardial Infarction in Patients With Left Bundle Branch Block

Background

Current electrocardiographic algorithms lack sensitivity to diagnose acute myocardial infarction (AMI) in the presence of left bundle branch block.

Methods and Results

A multicenter retrospective cohort study including consecutive patients with suspected AMI and left bundle branch block, referred for primary percutaneous coronary intervention between 2009 and 2018. Pre‐2015 patients formed the derivation cohort (n=163, 61 with AMI); patients between 2015 and 2018 formed the validation cohort (n=107, 40 with AMI). A control group of patients without suspected AMI was also studied (n=214). Different electrocardiographic criteria were tested. A total of 484 patients were studied. A new electrocardiographic algorithm (BARCELONA algorithm) was derived and validated. The algorithm is positive in the presence of ST deviation ≥1 mm (0.1 mV) concordant with QRS polarity, in any lead, or ST deviation ≥1 mm (0.1 mV) discordant with the QRS, in leads with max (R|S) voltage (the voltage of the largest deflection of the QRS, ie, R or S wave) ≤6 mm (0.6 mV). In both the derivation and the validation cohort, the BARCELONA algorithm achieved the highest sensitivity (93%–95%), negative predictive value (96%–97%), efficiency (91%–94%) and area under the receiver operating characteristic curve (0.92–0.93), significantly higher than previous electrocardiographic rules (P<0.01); the specificity was good in both groups (89%–94%) as well as the control group (90%).

Conclusions

In patients with left bundle branch block referred for primary percutaneous coronary intervention, the BARCELONA algorithm was specific and highly sensitive for the diagnosis of AMI, leading to a diagnostic accuracy comparable to that obtained by ECG in patients without left bundle branch block.

Antitachycardia pacing for shock prevention in patients with hypertrophic cardiomyopathy and ventricular tachycardia

BACKGROUND

Hypertrophic cardiomyopathy (HCM) carries an increased risk of sudden death due to ventricular arrhythmias (VAs). The implantable cardioverter-defibrillator (ICD) is a well-established therapy for treatment of VA. Monomorphic ventricular tachycardias (MVTs) are frequent in HCM patients and suitable for antitachycardia pacing (ATP) termination.

OBJECTIVE

The purpose of this study was to describe ventricular tachycardia (VT) characteristics in a population of HCM patients with ICD and to study the effectiveness and safety of ATP for MVT.

METHODS

Data were obtained from the multicenter prospective observational UMBRELLA trial, which included all patients with HCM and ICD followed by the CareLink Monitoring System. All episodes of VA were collected and analyzed. ATP effectiveness and safety were described, and factors related to ATP effectiveness were studied with generalized estimating equation (GEE) models.

RESULTS

Among 251 patients followed for 47 months, 67 (26.7%) were implanted as secondary prevention. Fifty-six patients presented 326 episodes of VA (286 [87%] MVT). Mean cycle length was 312 ± 64 ms. Among 264 MVTs that received ICD therapy, 202 (76.5%) were ATP terminated. The first ATP burst was effective in 169 episodes (68.4%), and overall effectiveness of the first or second ATP burst was 73.8%. Multivariate GEE-adjusted analysis showed 2 variables related to ATP effectiveness: programming fast VT zone On vs Off (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.5-5.2; P = .03) and programming ≥2 ATP bursts vs 1 burst only (OR 1.6; 95% CI 1.2-3.4; P = .04; and OR 2.9; 95% CI 1.8-6.3; P = .02; respectively).

CONCLUSION

MVT is the predominant VA in HCM patients with ICD. ATP is highly effective in terminating the majority of MVTs, and its proved effectiveness should guide device selection and programming in order to avoid unnecessary high-energy shocks.

Mortality and morbidity reduction after frequent premature ventricular complexes ablation in patients with left ventricular systolic dysfunction

Aims

Ablation of frequent premature ventricular complexes (PVCs) improves left ventricular ejection fraction in patients with left ventricular (LV) systolic dysfunction. This study aims to evaluate the long-term hard outcomes and potential prognostic variables in this population.

Methods and results

Prospective multicentre study including 101 consecutive patients [56 ± 12 years old, 62 (61%) men] with LV systolic dysfunction and frequent PVCs who underwent PVC ablation before November 2015. The last evaluation performed was considered the long-term follow-up (LTFUP) evaluation. Mean follow-up was 34 ± 16 months (range 24–84 months). Ablation was successful in 95 (94%) patients. There was a significant reduction in the PVC burden from 21 ± 12% at baseline to 3.8 ± 6% at LTFUP, P < 0.001. Left ventricular ejection fraction improved from 32 ± 8% at baseline to 39 ± 12% at LTFUP (P < 0.001) and New York Heart Association class from 2.2 ± 0.6% to 1.3 ± 0.6% (P < 0.001). Brain natriuretic peptide levels decreased from 136 (78–321) to 68 (32–144) pg/mL (P = 0.007). Most of this improvement occurs during the first 6 months after ablation. Persistent abolition of at least 18 points of the baseline PVC burden was independently and inversely associated with the composite endpoint of cardiac mortality, cardiac transplantation, or hospitalization for heart failure during follow-up [hazard ratio 0.18 (0.05–0.66), P = 0.01].

Conclusion

In patients with LV systolic dysfunction, ablation of frequent PVCs induces a significant improvement in functional, structural, and neurohormonal status, which persists at LTFUP. A sustained reduction in the baseline PVC burden is associated with a lower risk of cardiac mortality, cardiac transplantation, or hospitalization for heart failure during follow-up.

Beta-blocker therapy is associated with a lower incidence of syncope due to fast ventricular tachycardias among implantable cardioverter-defibrillator patients with left ventricular dysfunction: results from a multicenter study

INTRODUCTION

Among implantable cardioverter-defibrillator (ICD) patients, a substantial proportion of syncopes are due to fast ventricular tachycardias (FVTs). In the experimental models of ventricular tachycardias, the arterial vasoconstriction plays an important role in recovering the arterial pressure. Since beta-blockers increase vascular resistance, we hypothesized that beta-blockers could reduce the occurrence of syncope due to FVTs. Our objective was to determine the relationship between the beta-blocker therapy and the incidence of syncope in FVT (cycle length [CL] 250-320 ms) occurring in ICD patients. Slow VTs were excluded because of the lack of symptoms and VF episodes because of the small number.

METHODS AND RESULTS

In this multicenter study, 226 patients (LVEF 31 ± 10%) with single-chamber ICDs were followed. FVT programming was standardized, including antitachycardia pacing (ATP) as initial therapy. Symptoms were correlated with ICD-stored episode data of FVTs. The beta-blocker therapy was determined at each FVT presentation. We analyzed 289 FVTs (CL 291 ± 21 ms; 77% under beta-blockers; median of the duration:8 s) occurring consecutively in 52 ICD patients. The frequency of FVT-related syncope was 22 (7.6%). Beta-blockers were associated with a lower heart rate preceding FVT (85 ± 22 vs. 94 ± 23 bpm; p = 0.009), a higher ATP effectiveness (86 vs. 57%; p < 0.001), a lower duration of episodes (8 [2] vs. 10 [14] s; p < 0.001), and a lower incidence of FVT-related syncope (4.5 vs. 18%; p < 0.001). By logistic regression, a FVT > 8 s (OR = 21; p = 0.003) and the beta-blocker therapy (OR = 0.3; p = 0.012) were found as independent predictors of syncope.

CONCLUSION

Among ICD patients with left ventricular dysfunction, beta-blockers are associated with a lower incidence of FVT-related syncope.