Cardioverter-defibrillator Implantation Research Articles

Ventricular tachycardia initiation patterns on electrograms of implantable defibrillator devices

Abstract Introduction Sudden cardiac death is an unexpected death from a cardiac origin attributed by arrhythmias such as ventricular fibrillation (VF) and ventricular tachycardia (VT). The predominant treatment to terminate VT and VF is the implantation of an implantable cardioverter defibrillator (ICD). Currently, VT initiation in specific and small cohorts such as structural heart disease and reduced left ventricular ejection fraction patients have been explored. However, there is limited literature comparing the association between VT initiation patterns and defibrillators therapy outcome. This study aimed to investigate the most prevalent type of VT initiation from stored electrograms on ICDs and to explore the association between VT initiation pattern and therapy outcome (i.e., the ability to terminate VT). Method 344 stored electrograms amongst 65 patients from an existing database were visually inspected to classify VT initiation pattern as sudden onset (not preceded by premature ventricular complexes), non-sudden onset (preceded by premature ventricular complexes) and pacing-induced (device induced). Wilcoxon rank sum and Fisher’s Exact tests were used to assess differences between these groups. Mixed-effect logistic regression models accounting for multiple events occurring in individual patients were used to investigate association between the VT initiation pattern and therapy outcome. Results The mean age for the study group was 53±20 years and 54 (83%) subjects were males. Aetiology includes: 29 ischemic heart disease (45%), 10 hypertrophic cardiomyopathy (15%), 8 dilated cardiomyopathy (12%) and 18 other conditions (28%). Non-sudden onset VT (51%) was the most prevalent type of VT initiation pattern on defibrillators followed by sudden onset (44%) and pacing induced (5%). Non-sudden onset was 3 times more likely than the other 2 groups combined to be associated with unsuccessful therapies with an OR: 3.05 (95% confidence interval: 1.14, 8.15); p =0.03. There was no association between pacing-induced onset and unsuccessful therapies with an OR: 0.33 (95% confidence interval: 0.03, 3.33); p = 0.35. No association was identified for any of the three initiation patterns versus the other two combined and unsuccessful therapies when mixed-effect models were constructed. Discussion/ Conclusion: This study is consistent with other findings showing that non-sudden onset (51%) is the most prevalent VT onset. Pacing-induced VT accounted for 5% of VT with the predominant reason for initiation being undersensing of R-waves leading to pacing on the T-wave. This study reiterates the importance of programming strategies to prevent pacing induced VT. No associations were found with VT initiation and therapy outcome with mixed-effect models, possibly due to pseudo-replication being a limitation of this study. Prospective studies should be carried out in future to attempt to maximise success rate and establish the most effective treatment in ICDs.

Impact of taurolidine use during cardiac electronic implantable device implantation in heart failure patients

Abstract Background Cardiac Implantable Electronic Device (CIED) infections represent a critical health threat with potentially fatal consequences. The TauroPace™ is an innovative solution that contains taurolidine specifically formulated to eradicate environmental microbial contamination on the surface of CIEDs. To date, scarce data are available in literature about Taurolidine’s effect on preventing CIED infections. Aims To investigate the ability of the TauroPace™ to reduce major CIED infections through 12 months follow-up in fragile patients such as heart failure (HF) patients. Methods This prospective cohort study included patients with HF and an ejection fraction ≤ 35%, who were referred for de novo implantation, upgrading or battery replacement of Implantable Cardioverter Defibrillator (ICD) or Cardiac Resynchronization Therapy with defibrillator (CRT-D), to the EP labs of two tertiary care hospitals. Patients with previous CIED infections were excluded. During the procedures, the catheters were submerged in the TauroPace™ solution and the pocket was irrigated with taurolidine. Starting from the main risk factors for the development of CIED-related infections as identified in the literature (including individuals with heart failure, diabetes, chronic kidney disease, and those undergoing defibrillators implantation, especially upgrades or revisions procedure), we conducted a meta-analysis and meta-regression to evaluate the relationship between the treatment effect's magnitude and various predictors. To estimate the incidence of CIED infections in high-risk subgroups, we utilized the percentage of patients with diabetes, chronic renal failure, or those undergoing replacement, upgrade, or revision procedures, along with other risk factors for CIED infections, as continuous variables and we were able to modify our comparison parameters based on the real percentage of risk factors that we obtained. Results The study included 69 consecutive patients (53 male [76.8 %], 34 ischemic [49,3 %], median [IQR] age 68 [59-73] years, 19 diabetic [27.5 %] and 34 [49.2 %] with chronic renal failure), of whom 39 (56.5 %) received ICD and 30 (43.5 %) CRT-D, with 28 (40.6 %) replacement procedures, 2 (2.9 %) upgrades, and 39 (57%) de novo implantations. During the one-year follow-up period, 1 [1.45 (Standard Error, SE 0.014) %] patient undergoing a CRT replacement developed an infection. The available data from the literature estimate an incidence rate of 6% (SE 0.0106) when considering a selected patient population with a very high risk of infection similar to our population. This is significantly higher than our cohort (z-score -2.5447, p value = 0.011). Conclusions Taurolidine has yielded promising results, demonstrating a low incidence rate of infections within our cohort of high-risk patients, which is below that reported in the literature. Further data will be necessary to validate and confirm these initial findings.

Factors influencing inappropriate device therapy in implantable cardioverter defibrillators: a predictive analysis

Abstract Background Implantable cardioverter defibrillator (ICD) implantation and subsequent ICD therapy have shown to be efficacious in the prevention of sudden cardiac death. However, patients with an ICD are at risk of inappropriate device therapy (IDT), which is associated with worse outcomes, reduced quality of life (QoL), and may influence psychosocial and mental wellbeing. Purpose This study aimed to predict which patients are at risk of IDT by investigating the influence of pre-implant clinical parameters on occurrence of IDT. Methods From January 2010 to December 2019, patients who received an ICD in our medical center, were included in a prospective registry. Only patients with ICD (including ICDs used for cardiac resynchronization therapy, i.e. CRT-D) with an atrial lead were included in the current analysis, to better distinguish between appropriate and inappropriate device therapy. After implant, the device was interrogated at least every 6 months and clinical symptoms related to the device, recorded events, and relevant technical setting changes were recorded. IDT was defined as antitachycardia pacing (ATP) or shock delivered for any reason other than ventricular arrhythmia. Follow-up ended after IDT, death, or loss-to-follow-up. Results 428 patients underwent an implantation of a dual chamber ICD or CRT-D of various manufacturers. 14 patients were lost to follow-up within the first year and one patient was excluded because of a dislocated atrial lead, leaving 413 patients (76% male, mean age 67±9.7 years, 39% CRT-D) with a minimum of 1-year follow-up. During a mean of 5.3 (±3.0) years, 136 (32.9%) patients received appropriate therapy and 36 (8.7%) patients received IDT. Of those 36 patients, 18 patients received only ATP, 12 received ATP followed by a shock, and 6 patients received a shock without prior ATP. The median time from implantation to IDT was 2.8 [0.3-5.8] years. Univariate logistic regression on 40 clinical parameters followed by a forward multivariate logistic regression was performed. The area under the ROC curve of the resulting multivariate model was 0.724 (95%CI 0.622-0.826). Cox regression analysis resulted in device type (CRT-D) (HR=0.533, 95%CI 0.234-1.211, p=0.133), use of mineralocorticoid receptor-antagonists (MRA) (HR=0.280, 95%CI 0.104-0.754, p=0.012), use of diuretics (HR=3.378, 95%CI 1.479-7.714, p=0.004), and eGFR (HR=1.217, 95%CI 0.972-1.523, p=0.087) as predictors of IDT. A history of atrial fibrillation was not a significant predictor of IDT. Conclusion This study identified CRT-D and use of MRAs to be protective against IDT, and use of diuretics and lower eGFR as risk factors of IDT. To inform patients optimally, pre-implant assessment of those factors could help identify patients at higher risk of IDT. Furthermore, it could dictate more cautious device programming and consequently reduce rates of IDT, reducing the negative influence of IDT on QoL and wellbeing in the ICD population.

In-hospital outcomes of anterior versus non-anterior st elevation myocardial infarction complicated with complete atrioventricular block

Abstract Background Complete atrioventricular block (CAVB) is an infrequent complication of acute ST-elevation myocardial infarction (STEMI), and information on its outcomes is scarce. We aimed to address the characteristics and in-hospital outcomes of patients with anterior versus non-anterior STEMI complicated with CAVB in a contemporary, nationwide, all-comer registry, in the U.S. Methods Using the National Inpatient Sample (NIS) database, we identified patients who were hospitalized with STEMI, complicated with CAVB between 2016- 2019. Patients with any cardiac implantable electronic device (CIED) in-situ were excluded. Baseline characteristics, in-hospital procedures and outcomes including time to temporary or permanent pacemaker (PPM)/implantable cardioverter defibrillator (ICD) implantation, length of stay and mortality were collected. Results A total of 17470 patients, were hospitalized with a primary diagnosis of STEMI and concomitant diagnosis of CAVB, 2755(15.8%) with Anterior and 14715(84.2%) with non-anterior STEMI. Non-anterior STEMI patients included more women, had higher prevalence of hypertension, dyslipidemia, smoking history and chronic pulmonary disease, while anterior STEMI patients had higher prevalence of chronic kidney disease and ischemic cardiomyopathy. Anterior STEMI patient had significantly higher rate of in hospital death [955 (35%) vs 2220 (15%), p<0.001], CPR, VT/VF, cardiac arrest, acute heart failure, respiratory failure, mechanical ventilation >96 hours and acute kidney injury. In both groups 40% received temporary pacemaker, but mean time to implantation was longer in anterior STEMI patients [1.1±3.3 vs 0.3±1.2 days, p<0.001]. Rate of any permanent CIED implantation was also significantly higher in the anterior STEMI patients with longer time to PPM implantation, [3.3±3.5 vs 2.8±2.8 days, p<0.001]. Use of mechanical circulatory support devices was significantly higher in anterior STEMI patients. Conclusion In STEMI patients complicated with CAVB, in-hospital outcomes of anterior STEMI were worse comparing to non-anterior STEMI, with significantly higher rates of in-hospital death, in-hospital complications and CIED implantations.

Cardiac implantable electronic devices following orthotopic heart transplantation: insights on indications and outcomes from a single centre experience

Abstract Background Need for cardiac implantable electronic devices (CIED) after orthotopic heart transplantation (OHT) ranges from 7 to 24% of cases depending on several patient and procedural related factors. Purpose The aims of this study were to investigate the frequency, indications and the predictors of CIED implantation (especially permanent pacemaker [PPM]) following biatrial anastomosis OHT. Methods A retrospective, single centre, observational study was conducted, including all the patients who underwent OHT between May 1990 and October 2023 at our Institution. For each patient clinical and procedural information were collected and a long-term active follow-up was performed. The primary endpoint of the study was PPM or implantable cardioverter defibrillator (ICD) implantation while all-cause mortality or de novo OHT was a secondary endpoint. Uni- and multivariable logistic regression analyses were performed to identify factors associated with PPM implantation. Results Overall, 546 patients were included and followed-up for a median of 8 years [IQR 1.2-14.3]. During this time frame, 89 (16.3%) patients required PPM implantation (only one patient [0.2%] underwent ICD implantation) at median time of 110 days [IQR 25-2230] after OHT. The main indication for PPM implantation was the development of sinus node dysfunction in 60 patients (67.4%) whereas 29 (32.6%) patients with atrioventricular block required PPM implantation. During follow-up, 265 deaths (48.5%) occurred but no significant differences in long-term prognosis were observed between patients requiring CIED implantation and those who did not (45.5% vs. 49.1%, p-value=0.53, figure). At multivariable analysis, impaired renal function (i.e. low eGFR), cardiac allograft vasculopathy, the occurrence of severe heart transplant rejection and a higher BMI were factors associated with PPM implantation (table). Conclusions Among patients undergoing OHT with biatrial anastomosis technique, PPM implantation is not uncommon but it does not negatively impact on prognosis. Several factors, especially severe heart transplant rejection, cardiac allograft vasculopathy and impaired renal function can help identifying patients at higher risk of PPM.TableFigure

Anatomical considerations for the subcutaneous implantable cardioverter-defibrillator (SICD) implantation: a cadaver-based analysis

Abstract Background Subcutaneous implantable cardioverter-defibrillators (SICDs) offer primary and secondary prevention of sudden death without transvenous leads in individuals not requiring pacing therapy. Intermuscular placement of the SICD generator between the latissimus dorsi (LDM) and serratus anterior (SAM) muscles is often recommended. This specific technique results in reduced defibrillation impedance and subsequently optimal defibrillation thresholds, reduced risk of pocket complications and infections, reduced device migration, and enhanced patient comfort and cosmetic outcomes. Despite the recommendation for an intermuscular implant technique utilizing a mid-axillary incision line, there is limited research describing this anatomical space to avoid complications. In this anatomic study, we examined this anatomical space. Our aim was to provide a better understanding of the interplay between the involved muscles and a proper location of an incision line. We also defined the location of the long thoracic nerve (LTN) relative to this space, which if transected, would lead to a winged scapula. Methods We examined 18 cadavers; 12 (66.7%) were female donors and 6 (33.3%) were males. We measured the distance from the anterior border of the LDM in relation to the cadaver back (A) and in relation to the anterior-posterior diameter of the chest (B). We performed these measurements at the 5th and 7th rib levels, and then averaged these measurements. We also measured the distance from the back to where the LTN enters SAM at the 4th, 5th, and 6th ribs. Results Analysis of the obtained data showed that the mean distance from the back to the anterior border of LDM at the 5th rib was 7.55 cm (5.65 – 10.85 cm) and at the 7th rib was 7.60 cm (5.35– 10.35 cm). Mean distance from the back to the anterior LDM border in both 5th and 7th ribs combined was 7.58 cm (5.50 – 1.06 cm). The mean anterior-posterior diameter of the chest wall at the fifth rib was 21.45 cm (18.55 – 24.75 cm). The mean A/B ratio (that is the ratio between the distance from the back to the anterior LDM border in comparison to the anterior-posterior chest diameter) was 0.4 with a standard deviation of +/- 0.1 (range 0.27-0.45). The LTN was running anterior to the LDM border at the 4th rib level, and posterior to the LDM border at the 5th and 6th ribs level. The LTN entered the SAM at the 4th rib level in 6.6%, at the 5th rib in 46.6% and at the 6th rib in 46.6% of cadavers. Discussion Intermuscular technique for S-ICD implantation is recommended as the preferred procedural approach. In our postmortem study, the anterior LDM border was variable but posterior to the mid-axillary line with a variable A/B ratio of 0.27 – 0.45. Our study also demonstrates the proximity of the long thoracic nerve (LTN) in comparison to the anterior LDM border. Caution should be taken when implanting S-ICD devices to avoid LTN injury.

Ventricular arrhythmia events in patients with implantable cardioverter-defibrillator before and after the treatment with sodium-glucose co-transporter 2 inhibitors

Abstract Background The role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the treatment of chronic heart failure is expanding. However, the timing of implantable cardioverter-defibrillator (ICD) implantation for primary prevention in relation to the use of SGLT2i remains unclear. A small case series has described appropriate shocks from ICD in two patients following the initiation of SGLT2i, but a comprehensive analysis is lacking in the literature. Methods This study aimed to investigate the rate of ventricular arrhythmic burden and appropriate anti-tachycardia therapy from ICD before and after the initiation of SGLT2i therapy. We conducted a retrospective single-center analysis, comparing ventricular events from home monitoring reports three months before and three months after SGLT2i therapy initiation. Results Seventeen patients were enrolled in the study. At baseline, clinical characteristics were as follows: 13 (76%) were male, 9 (53%) had ischemic, 2 (12%) had valvular, and 6 (35%) had idiopathic cardiomyopathy. The mean end-diastolic volume (EDV) was 203 ± 90 ml, and the mean left ventricular ejection fraction was 0.36 ± 0.09. All patients were treated with beta-blockers, 14 (82%) with sacubitril-valsartan, 13 (76%) with aldosterone antagonists, 16 (94%) with furosemide, and 5 (29%) with amiodarone. SGLT2i started with dapagliflozin for 13 patients (76%), empagliflozin for 3 patients (18%), and canagliflozin for 1 patient (6%). Ten patients (59%) had single-chamber or dual-chamber ICDs, and 7 had implantable cardiac resynchronization therapy (CRT) defibrillators. In the three months before SGLT2i treatment, 4/17 patients had non-sustained ventricular tachycardia (NSVT), compared to 8/17 (23% vs. 47%, p-value 0.23) patients with NSVT after treatment. Seven patients (41%) experienced an increase in the rate of NSVT events, with one patient having 28 NSVT events after treatment versus none before treatment. No patients had anti-tachycardia therapy in the three months before treatment, while in the three months after SGLT2i treatment, 1 patient had ventricular tachycardia treated with anti-tachycardia pacing (110 days after the beginning of the treatment), and 2 patients had ventricular tachycardia treated with appropriate shocks (2 and 25 days after the initiation of SGLT2i treatment). Conclusion This small retrospective analysis revealed an increase in ventricular arrhythmic events in the three months following the initiation of SGLT2i. These findings highlight the need for a more extensive analysis to establish a stronger statistical correlation.

Clinical performance and safety of a two-lead cardiac resynchronization therapy system with a floating atrial sensing dipole

Abstract Background The incidence of complications after implantable cardioverter-defibrillator (ICD) and cardiac resynchronisation therapy (CRT-D) implantations is dependent on the number of implanted leads. The majority of CRT-D patients have unimpaired sinus node function and do not require atrial pacing. A two-lead CRT-D system with a floating atrial sensing dipole mounted on the right ventricular lead ((CRT-DX) allows dual chamber tachyarrhythmia detection, and atrio-ventricular sequential pacing with a reduced amount of implanted material. Purpose This study investigated the clinical efficacy and safety of the CRT-DX system. Methods This multicentre, single-arm study observed patients after de novo implantation of a CRT-DX system for 12 months. Patients were eligible for the study when chronotropic competence was proven by heart rates ≥100 bpm during exercise, premature ventricular contractions rate of < 5%/h and absence of atrioventricular block ≥ II. Intraoperatively measured p-wave amplitude of ≥ 1 mV was recommended. The primary safety endpoint was the additional implantation of a right atrial (RA) lead after the initial implantation. As indicators of efficacy, we report the changes in left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) class over the follow-up period. Results Overall, 110 patients were implanted with the complete CRT-DX system. Mean age of study participants was 62 ± 12 years and 77 (70%) were male. The underlying heart disease was non-ischemic in 66 (60%) patients and 103 (93%) had a left bundle branch block. NYHA class was II in 60 (54.5%) and III in 50 (45.5%) patients. ICD placement was performed in 13 (11.8%) patients for the secondary prevention of sudden cardiac death. A total of 104 patients completed the follow-up, 2 patients died, 1 had the system explanted for infection, 2 withdrew consent and 1 was lost to follow-up. The primary endpoint of RA lead implantation was met in 2 (1.8%) participants (Figure 1). One patient required atrial pacing and one patient, who had shown a p-wave amplitude < 1 mV at implantation, lost atrial sensing. The mean RA sensing amplitude remained stable during follow-up (4.6 ± 1.8 mV, 4.9 ± 1.8 mV and 4.6 ± 1.8 mV at 1, 6 and 12 months, respectively; Figure 2). The LVEF improved by 14.7% ± 11.0%, from 26.3% ± 6.9% to 40.8% ± 10.7% (p < 0.00001). Changes in NYHA class were available in 87 patients with 35 (40.2%) improved by one class and 13 (14.9 %) by two classes. Thirty-four (39.1%) had no change and 5 (5.7%) worsened by one class (global p < 0.00001). Conclusion The two-lead CRT-DX system showed a low requirement of subsequent RA lead implantations (1.8%) and stable RA sensing amplitudes. Our results suggest a CRT response similar to that of conventional three-lead CRT-D systems. CRT-DX systems appear to be a feasible alternative for patients with chronotropic competence.Kaplan-Meier curve for primary endpointDaily mean RA sensing amplitude

The safety and feasibility of same-day discharge after subcutaneous implantable cardioverter defibrillator implantation

Abstract Introduction Subcutaneous Implantable cardioverter defibrillators (S-ICDs) are now progressively administered as a day-case procedure. While existing data supports the feasibility and safety of same-day discharge after transvenous ICD implantation, comparable evidence for S-ICDs is not well established. This study addresses this by presenting data from the most extensive population documented in the medical literature. We seek to evaluate the feasibility and safety of same-day discharge after S-ICD implantation. Purpose To investigate the feasibility and safety of same-day discharge following S-ICD implantation. Methods A retrospective analysis was conducted, encompassing data from all patients who underwent S-ICD implantation at our institution between January 2011 to April 2023 (n=240). The cohort was stratified into two groups: those discharged on the same day of the procedure (SD, n=124) and those subject to at least overnight hospital observation (OD, n=116). The medical records were reviewed during this period aiming to identify potential complications. Complications were categorized as device-related complications or inappropriate shock. Specific events, such as inappropriate shocks; lead revision; infection necessitating lead or generator extraction; pocket hematoma requiring drainage, blood transfusion, or prolongation of hospitalization; and other complications related to the lead or generator prompting medical or surgical intervention were documented. An inappropriate shock was defined as one delivered for any rhythm other than ventricular fibrillation or ventricular tachycardia. Results Among the 240 patients included in the study, 123 were scheduled for a day case procedure, while the remaining 117 underwent S-ICD implantation as in-patients. Notably, 112(91%) out of 123 planned-day patients and 12 in-patients (SD, total n=124) were successfully discharged on the same day. A substantial proportion (84%) of SD group had undergone the procedure for primary prevention. Patients with congenital heart disease were predominantly observed overnight. Defibrillation testing (DFT) is routine in our practice to ensure S-ICD integrity and was conducted in all S-ICD patients unless contraindicated. The success rate of DFT among attempted patients was high, standing at 72% and 78% in the SD and OD groups, respectively. The incidence of device-related complications was comparable between the two groups. The SD group displayed a slightly higher superficial infection rate but the incidence of inappropriate shocks was lower in the SD groups. Conclusion Based on our findings, same-day discharge following S-ICD implantation emerges as an appropriate practice. Our data strongly supports the assertion that same-day discharge in this context is safe and feasible, offering valuable insights into the optimal post-procedural management of S-ICD patients.Table 1ComplicationsTable 2Defibrillation Test

Prognostic impact of permanent pacemaker implantation after cardiac surgery

Abstract Introduction Brady-arrhythmias with subsequent need for permanent pacemaker implantation is after cardiac surgery. It is not known whether the need of a permanent pacemaker influences long-term prognosis after cardiac surgery. Methods This large, nationwide study included all patients who underwent cardiac surgery in Sweden 2006-2020. Data was obtained from the Swedish Cardiac Surgery Registry, The Swedish ICD and Pacemaker Registry, The Swedish National Patient Register, and the Swedish Cause of Death Register. Patients who received a permanent pacemaker within 30 days were compared to those who did not. Exclusion criteria were previous pacemaker or implantable cardioverter defibrillator implantation and death within 30 days. Missing data were handled by multiple imputation. Cox regressions models were used to obtain hazard ratios (HR) with 95% confidence intervals (95%CI). The model was adjusted for age at operation, sex, left ventricular ejection fraction (EF), type of surgery, previous myocardial infarction, diabetes, peripheral artery disease, chronic respiratory disease, hypertension and atrial fibrillation. Results In total, 74 606 patients were included out of which 2 150 (2.9%) received a pacemaker within the first 30 days after cardiac surgery. Those who had a pacemaker implanted were older, more often female, had lower EF and significantly more often atrial fibrillation and peripheral artery disease. These patients were less likely to have diabetes, hypertension and previous myocardial infarction. Pacemaker implantation was associated with a higher risk of all-cause mortality (adjusted HR: 1.09 (95%CI=1.00-1.19), p=0.035, Figure 1) and heart failure hospitalization (adjusted HR: 1.45 (95%CI=1.30-1.62), p<0.001). Cardiovascular mortality had similar estimates but did not reach statistical significance (HR: 1.09 (95%CI=0.99-1.24), p=0.15). Conclusions The presence of brady-arrhythmias requiring permanent pacemaker implantation after cardiac surgery is associated with a higher risk of mortality and heart failure hospitalization. Measures should be taken to minimize the risk of injury to the conduction system leading to brady-arrhythmias during cardiac surgery.

Sex differences in hospitalization for ventricular arrhythmia after a first myocardial infarction in patients without indication for implantable cardioverter-defibrillator implantation

Abstract Background Ventricular arrhythmias (VAs) represent a serious complication of myocardial infarction (MI). Incidence rate of VAs and sudden cardiac death is commonly reported to be lower in women than in men after MI (1,2). While data regarding SCD and VAs after MI in patients with implantable cardioverter defibrillator (ICD) are well described, data regarding the incidence of readmissions for VA in patients without ICD implantation criteria after a first MI are scarce, as well as the impact of sex on their occurrence. Objective This study aims to investigate the impact of sex on VA occurrences in post-MI patients without ICD implantation criteria. Methods This study was conducted using the French national health data system using electronic codes for procedures (CCAM) and hospitalizations data (PMSI). The study population consisted of patients discharged after a first MI and without criteria for ICD implantation. Results Between January 2014 and January 2015, 137,736 patients were hospitalized in France with a diagnosis of first MI and were followed using CCAM and PMSI codes. Among the 112,465 alive at discharge, 6838 patients were excluded due to criteria for the implantation of an ICD for primary or secondary prevention. Of the remaining 105,629 patients, 1600 (1.51%) were rehospitalized for VA with a median delay of 505 days (IQR 110-1208). Men had almost twice the risk of VA than women after initial discharge for MI (OR 1.88, 95% CI 1.65-2.14; p<0.0001). Among the 72,103 men included, 1240 (1.72%) were rehospitalized for VA with a median delay of 514 days (IQR 107-1212). Factors independently associated with VA in men were previous atrial fibrillation (OR 1.91, 95% CI 1.66 - 2.21, p<0.0001), previous vascular disease (OR 1.28, 95% CI 1.10 - 1.50, p=0.002), absence of coronary angioplasty (OR 1.28, 95% CI 1.10 - 1.50, p=0.002), previous diabetes (OR 1.19, 95% CI 1.04 - 1.36, p=0.012), previous hypertension (OR 1.19, 95% CI 1.05 - 1.34, p=0.007), previous or in-hospital congestive heart failure (OR 1.47, 95% CI 1.03-2.08, p=0.032 and OR 1.65, 95% CI 1.32-2.07, p<0.0001), and age (patients between 60 and 79 yo being at the higher risk of VA compared to <60 and >80yo patients, p=0.002 and <0.0001 respectively). Among the 33,526 women included, 360 (1.07%) were rehospitalized for VA with a median (IQR) delay of 461 days (116-1159) after MI. Factors independently associated with VA were previous atrial fibrillation (OR 1.68, 95% CI 1.30 - 2.18, p<0.0001), previous vascular disease (OR 1.37, 95% CI 1.01 - 1.84, p=0.041), and age (patients between 60 and 79 yo being at the higher risk of VA compared to >80yo patients, p=0.001). Conclusion The risk of readmission for VAs after a first MI is significantly lower in women compared to men, with distinct predictive factors. These findings suggest that sex-specific VA risk stratification and management strategies may be warranted after an initial MI.Sexe influence on post-MI VAs occurence

The cardiac blood transcriptome predicts de novo onset of atrial fibrillation in heart failure

Heart failure (HF) increases the risk of developing atrial fibrillation (AF), leading to increased morbidity and mortality. Therefore, better prediction of this risk may improve treatment strategies. Although several predictors based on clinical data have been developed, the establishment of a transcriptome-based predictor of AF incidence in HF has proven to be more problematic. We hypothesized that the transcriptome profile of coronary sinus blood samples of HF patients is associated with AF incidence. We therefore enrolled 192 HF patients who were selected for biventricular cardioverter defibrillator implantation. Both coronary sinus and peripheral blood samples were obtained during the procedure. Patients were followed-up during two years and AF occurrence was based on interrogation of the defibrillator. A total of 96 patients stayed in sinus rhythm (SR) during follow-up, 13 patients developed AF within 1 year and 10 patients developed AF during the second year of follow up. Gene expression profiling of coronary sinus samples led to the identification of 321 AF predictor genes based on their differential expression between patients developing AF within 1 year of blood sampling and patients remaining in SR. The expression levels of these genes were combined to obtain a molecular atrial fibrillation prediction score for each patient which was significantly different between both patient groups (Mann-Whitney, p = 0.00018). We conclude that the cardiac blood transcriptome of HF patients should be further investigated as a potential AF risk prediction tool.

AN UNUSUAL LEFT VENTRICULAR APICAL MASS COMPLICATING ACUTE MYOCARDIAL INFARCTION

Abstract An 34–year–old man presented to the emergency department of our hospital with palpitations and presyncope. He was a smoker but had no others known cardiovascular risk factors. At admission, his electrocardiogram (ECG) showed sustained monomorphic ventricular tachycardia (VT) at a rate of 187 beats per minute. The VT was successfully treated with synchronized direct current cardioversion. The ECG in sinus rhythm showed Qs from V1 to V6 with ventricular repolarization anomalies in the same site suspicious for previous anterior necrosis. A transthoracic echocardiogram revealed akinetic apex, akinesia of middle segments of the interventricular septum, anterior and lateral walls, Left Ventricular (LV) ejection fraction of 30% and a large apical mass suspicious for LV thrombus. The patient was admitted to the coronary care unit and taken to the Cath lab that showed total left anterior descending mid–segment occlusion. Due to the chronicity of the condition, the patient was recommended to optimal medical therapy. Suspecting LV thrombus, the patient began treatment with unfractionated heparin i.v. and subsequently imbricate therapy with enoxaparin s.c. and warfarin. Additionally, the patient underwent subcutaneous implantable cardioverter defibrillator (S–ICD) implantation for secondary prevention of sudden cardiac death. At echocardiographic follow–up one week after discharge, the apical mass remained unchanged despite warfarin therapy with INR at target. For this reason, the patient was recommended to perform a Cardiovascular magnetic resonance (CMR). Three months after S–ICD implantation, a CMR was performed which showed transmural areas of late gadolinium enhancement involving all apical segments and middle segments of the interventricular septum which allowed the diagnosis of a large intramyocardial dissecting hematoma (IDH) of left ventricle. IDH is a rare complication of ST–elevation myocardial infarction (STEMI), it is an unusual form of subacute cardiac rupture and could be fatal. It usually consists of a cavity or channels within the myocardium. Its prognosis varies according to its location, but generally apical IDH have more favorable outcome with a higher likelihood of spontaneous retraction. We report this case because the IDH is a diagnostic challenge and it represents an extremely rare and poorly described event in the literature.

INTERATRIAL BLOCK AS A FIRST CLINICAL PRESENTATION OF ATRIAL CARDIOMYOPATHY RELATED TO A NOVEL LMNA VARIANT: A CASE REPORT

Abstract Interatrial block (IAB) is a conduction delay in Bachmann’s bundle with a well–described association with structural heart disease, supraventricular arrhythmias, and cardiovascular events. We report the case of an asymptomatic 35–year–old man in whom the presence of IAB at electrocardiogram led to a comprehensive evaluation including speckle–tracking echocardiography, 24 h Holter monitoring, and genetic testing. Speckle–tracking echocardiography demonstrated a decrease in the longitudinal strain of interventricular septum, a typical feature of LMNA–related cardiomyopathy, and decreased indices of left atrial deformation. A diagnosis of cardiac laminopathy related to the frame shift variant c.1367 (p.Asn456Thrfs*24) of the LMNA gene was made. A dual–chamber implantable cardioverter defibrillator implantation was performed for the high risk of life–threatening ventricular tachyarrhythmias. This case demonstrates that IAB could be a rare presentation of a life–threatening laminopathy. Strain echocardiography is an essential tool to evaluate the deposition of fibrosis tissue in subclinical cardiomyopathies. Our report describes a novel variant of LMNA gene associated with a high risk of sudden cardiac death.

Atrioventricular block in patients with acute myocardial infarction in a state of cardiogenic shock

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Hospital of Virgen Macarena. Introduction Atrioventricular block (AVB) is a complication to consider in patients with acute myocardial infarction (AMI), constituting a factor in decompensation that can contribute to the shock state in some patients. Purpose The study analyzed the incidence of AVB and its relationship with the culprit artery, mortality, and the final need for device implantation. Methods A single-center, observational, retrospective study included patients admitted to the Coronary Care Unit in a state of cardiogenic shock in the context of AMI between July 2011 and September 2022. Results A total of 298 patients with AMI in a state of shock were included. The average age of the sample was 69 years, with 66.7% being male, 66.8% having hypertension, 55% having dyslipidemia, 50% having diabetes, and 33% being smokers. Nearly half of the patients (47.86%) already presented with a Killip Kimball class IV at the time of admission. The left anterior descending artery (LAD) was responsible for the infarction in 57.4% of cases, and the right coronary artery (RCA) in 24.8%. The incidence of AVB was significantly higher in patients with RCA infarctions compared to LAD (39.1% vs. 3.1%) and compared to other vessels (39.1% vs. 6.69%), with this significance remaining in any type of acute coronary syndrome. The need for device implantation was infrequent. Patients with LAD infarctions required more implantation of implantable cardioverter-defibrillators (ICDs) compared to RCA infarctions (4.43% vs. 0.49%), and RCA infarctions required more conventional pacemaker implantation (2.7% vs. 0%). A better prognosis was observed in RCA involvement with lower mortality compared to other vessels (OR 0.35, 95% CI 0.19-1.6; p=0.01) and compared to LAD involvement (OR 0.44, 95% CI 0.23-0.84; p=0.013). Conclusions The incidence of AVB was a particularly common complication in patients in a state of shock with RCA infarctions. However, the mortality was significantly lower in this subgroup of patients. Regardless of the responsible artery, the need for device implantation was infrequent, with a notable need for ICDs in LAD involvement and pacemakers in RCA involvement.

Management of Catecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a primary electrical heart disease characterized by the development of polymorphic (including bidirectional) ventricular tachycardia in response to adrenergic stimulation. The leading clinical sign of CPVT is syncope provoked by physical or emotional stress, or adrenergic drugs administration. This disease is characterized by high mortality if not treated. The main treatment approach for CPVT is drug therapy with beta-blockers. Recently, however, there are more and more works stating that beta-blockers have lack of efficacy. Combination therapy with the antiarrhythmic drug of the IC class is one of the approaches before implementing the interventional treatment methods in several patients. Interventional methods include cardioverter defibrillator implantation and left side sympathectomy. This paper presents the modern view on the efficacy, safety, and indications for every management method for patients with CPVT.

Personalized screening before subcutaneous cardioverter-defibrillator implantation: Usefulness and outcomes in clinical practice—the S-ICD screening SIS prospective study

BackgroundElectrocardiographic screening before subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation is unsuccessful in around 10% of cases. A personalized screening method, by slightly moving the electrodes, to obtain a better R/T ratio has been described to overcome traditional screening failure. ObjectiveThe objectives of the SIS study were to assess to what extent a personalized screening method improves eligibility for S-ICD implantation and to evaluate the inappropriate shock rate after such screening success. MethodsAll consecutive patients eligible for an S-ICD implantation were prospectively recruited across 20 French centers between December 2019 and January 2022. In case of traditional screening failure, patients received a second personalized screening. If at least 1 vector was positive, the personalized screening was considered successful, and the patient was eligible for implantation. ResultsThe study included 474 patients (mean age, 50.4 ± 14.1 years; 77.4% men). Traditional screening was successful in 456 (96.2%) cases. This figure rose to 98.3% (n = 466; P = .002) when personalized screening was performed. All patients implanted after successful personalized screening had correct signal detection on initial device interrogation. Nevertheless, after 1-year follow-up, 3 of the 7 patients (43%) implanted with personalized screening experienced inappropriate shock vs 18 of the 427 patients (4.2%) with traditional screening and S-ICD implantation (P = .003). ConclusionTraditional S-ICD screening was successful in our study in a high proportion of patients. Considering the small improvement in success of screening and a higher rate of inappropriate shock, a strategy of personalized screening cannot be routinely recommended.ClinicalTrials.gov identifier: NCT04101253

Effect of Implantable Cardioverter-defibrillators in Nonischemic Heart Failure According to Background Medical Therapy: Extended Follow-up of the DANISH Trial

The Heart Failure Collaboratory (HFC) score integrates types and dosages of guideline-directed pharmacotherapies for heart failure (HF) with reduced ejection fraction (HFrEF). We examined the effects of cardioverter-defibrillator (ICD) implantation according to the modified HFC (mHFC) score in 1116 patients with nonischemic HFrEF from the Danish Study to Assess the Efficacy of ICDs in Patients with Nonischemic Systolic HF on Mortality (DANISH). Patients were assigned scores for renin-angiotensin-system inhibitors, beta-blockers and mineralocorticoid receptor antagonists (0, no use; 1, < 50% of maximum dosage; 2, ≥ 50% of maximum dosage). The maximum score was 6, corresponding to ≥ 50% of maximum dosage for all therapies. The median baseline mHFC score was 4, and the median follow-up was 9.5 years. Compared with an mHFC score of 3-4, an mHFC score of 1-2 was associated with a higher rate of all-cause death (mHFC = 1-2: adjusted HR 1.67 [95% CI, 1.23-2.28]; mHFC = 3-4, reference; mHFC = 5-6: adjusted HR 1.07 [95% CI, 0.87-1.31]). ICD implantation did not reduce all-cause death compared with control (reference) (HR 0.89 [95% CI, 0.74-1.08]), regardless of mHFC score (mHFC = 1-2: HR 0.98 [95% CI, 0.56-1.71]; mHFC = 3-4: HR 0.89 [95% CI,0.66-1.20]; mHFC = 5-6: HR 0.85 [95% CI, 0.64-1.12]; Pinteraction, 0.65). Similarly, ICD implantation did not reduce cardiovascular death (HR 0.87 [95% CI, 0.70-1.09]), regardless of mHFC score (Pinteraction, 0.59). The ICD group had a lower rate of sudden cardiovascular death (HR, 0.60 [95% CI,0.40-0.92]); this association was not modified by mHFC score (Pinteraction, 0.35). Lower mHFC scores were associated with higher rates of all-cause death. ICD implantation did not result in an overall survival benefit in patients with nonischemic HFrEF, regardless of mHFC score.

Current US prevalence of myocardial injury patterns and clinical outcomes among hospitalised patients with familial hypercholesterolaemia: insight from the National Inpatient Sample—a retrospective cohort study

BackgroundFamilial hypercholesterolaemia (FH) increases propensity for premature atherosclerotic disease. Knowledge of inpatient outcomes among patients with FH admitted with acute myocardial injury (AMI) is limited.ObjectivesOur study aimed to identify myocardial...

Respiratory Function of Mitochondria in Patients with Coronary Heart Disease with Implantable Cardioverter-Defibrillator.

We studied the respiratory activity of mitochondria in peripheral blood leukocytes from 36 patients with coronary heart disease (CHD) and a history of ventricular tachyarrhythmias required cardioverter-defibrillator implantation. The measurements were carried out in incubation buffers with different oxidation substrates (succinate and pyruvate-malate mixture). In pyruvate-malate incubation buffer, oxygen consumption rate and respiratory control coefficients in patients with triggered device did not differ significantly from those in patients without cardioverter-defibrillator triggering. At the same time, respiratory control coefficients were below the reference values. In succinate buffer, values of mitochondrial parameters were significantly lower in patients with triggered devices. Our findings indicate that mitochondria of patients with non-triggered cardioverters-defibrillators have better functional and metabolic plasticity. It was concluded that activity of respiratory processes in mitochondria could be an indicator that should be taken into the account when assessing the risk of developing ventricular tachyarrhythmias.