Anxiety and depression as risk factors for ICD shocks and mortality in patients with an implantable cardioverter defibrillator - A systematic review

OBJECTIVE

To examine associations between baseline anxiety and depression and occurrence of ICD shocks and risk of mortality in patients with an implantable cardioverter defibrillator (ICD).

METHOD

We systematically searched EMBASE, PubMed, PsycINFO, and CINAHL for eligible studies fulfilling the predefined criteria.

RESULTS

We included 37 studies based on 25 different cohorts following 35,003 participants for up to seven years. We observed no association between baseline anxiety nor depression and the occurrence of ICD shocks. More than half of the identified studies (respectively 56% and 60%) indicated a significant association between baseline anxiety or depression and increased risk of mortality (anxiety: n = 5, ranging from Hazard ratios (HR):1.02 [Confidence intervals (CI) 95% 1.00-1.03] to HR:3.45 [CI 95% 1.57-7.60]; depression: n = 6, ranging from HR:1.03 [CI 95% 1.00-1.06] to HR:2.10 [CI 95% 1.44-3.05]). We found a significant association between high methodological quality of the primary study and the detection of a significant association (p < 0.01).

CONCLUSIONS

Baseline anxiety and depression are associated with increased risk of mortality in patients with an ICD, but not with occurrence of ICD shocks. Inclusion of baseline anxiety and depression in risk stratification of mortality may be warranted.

[Magnetic resonance imaging in cardiological patients : Basic principles for application]

Magnetic resonance imaging (MRI) can be safely performed in patients with cardiac implants such as pacemakers and cardioverter defibrillators (ICD). Prerequisites for safe use are knowledge of the physical conditions as well as professional indication and cardiological monitoring by an experienced cardiologist.

[Electromagnetic interference in 3D-mapping procedures]

Catheter-based ablation is nowadays a safe and widespread procedure for the treatment of cardiac arrhythmia. This requires exact anatomical knowledge both before and during the examination and is an important prerequisite for targeted treatment. At the beginning of the era of interventional catheter-based treatment, fluoroscopy was the only and usual means of visualization, whereas in the middle of the 1990s continuous 3D-mapping systems were developed for the non-fluoroscopic examination of patients. The correct use of these 3‑D systems, which non-fluoroscopically visualize the catheter and mostly identify mechanisms of arrhythmia in great detail, nowadays makes an important contribution to successful interventional catheter treatment of arrhythmia; however, it is not uncommon for patients with ventricular arrhythmia to also carry implanted electronic devices, such as pacemakers, defibrillators or less frequently left ventricular hemodynamic support systems. All implantable devices lead to electromagnetic interferences, which can complicate the diagnostics and treatment during electrophysiological examinations and ablation. This article addresses the adversities and experiences associated with magnet-based 3D systems and implantable electromagnetically active cardiac devices.

Effects of medically generated electromagnetic interference from medical devices on cardiac implantable electronic devices: A review

As cardiac implantable electronic devices (CIED) become more prevalent, it is important to acknowledge potential electromagnetic interference (EMI) from other sources, such as internal and external electronic devices and procedures and its effect on these devices. EMI from other sources can potentially inhibit pacing and trigger shocks in permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), respectively. This review analyzes potential EMI amongst CIED and left ventricular assist device, deep brain stimulators, spinal cord stimulators, transcutaneous electrical nerve stimulators, and throughout an array of procedures, such as endoscopy, bronchoscopy, and procedures involving electrocautery. Although there is evidence to support EMI from internal and external devices and during procedures, there is a lack of large multicenter studies, and, as a result, current management guidelines are based primarily on expert opinion and anecdotal experience. We aim to provide a general overview of PPM/ICD function, review documented EMI effect on these devices, and acknowledge current management of CIED interference.

Guideline-Directed Medical Therapy Before and After Primary Prevention Implantable Cardioverter Defibrillator Implantation in New Zealand (ANZACS-QI 66)

INTRODUCTION

Guidelines recommend angiotensin converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARB)/angiotensin receptor neprilysin inhibitors (ARNI); beta blockers; and mineralocorticoid receptor antagonists (MRA) in patients with symptomatic heart failure and reduced left ventricular ejection fraction before consideration of primary prevention implantable cardioverter defibrillator (ICD). This study aims to investigate dispensing rates of guideline-directed medical therapy (GDMT) before and after primary prevention ICD implantation in New Zealand.

METHODS

All patients receiving a primary prevention ICD between 2009 and 2018 were identified using nationally collected data on all public hospital admissions in New Zealand. This was anonymously linked to national pharmaceutical data to obtain medication dispensing. Medications were categorised as low dose (<50% of target dose), 50-99% of target dose or target dose based on international guidelines.

RESULTS

Of the 1,698 patients identified, ACEi/ARB/ARNI, beta blockers and MRA were dispensed in 80.2%, 83.6% and 45.4%, respectively, prior to ICD implant. However, ≥50% target doses of each medication class were dispensed in only 51.8%, 51.8% and 34.5%, respectively. Only 15.8% of patients were receiving ≥50% target doses of all three classes of medications. In the 1,666 patients who survived 1 year after ICD implant, the proportions of patients dispensed each class of medications remained largely unchanged.

CONCLUSION

Dispensing of GDMT was suboptimal in patients before and after primary prevention ICD implantation in New Zealand, and only a minority received ≥50% target doses of all classes of medication. Interventions are needed to optimise use of these standard evidence-based medications to improve clinical outcomes and avoid unnecessary device implantation.

Dual-chamber ICD for left bundle branch area pacing: the cardiac resynchronization and arrhythmia sensing via the left bundle (cross-left) pilot study

BACKGROUND

Left bundle branch area pacing (LBBAP) has emerged as a promising technique to deliver cardiac resynchronization therapy (CRT). However, safety and efficacy of ventricular arrhythmia sensing via the left bundle in implantable cardioverter-defibrillator (ICD) recipients remain unclear. We sought to evaluate the feasibility of a single LBBAP lead connected to a dual-chamber ICD in patients indicated with a CRT-D implantation.

METHODS

The CROSS-LEFT pilot study prospectively included 10 consecutive patients with a reduced ejection fraction and a complete left bundle branch block, indicated with a prophylactic CRT-D. A DF-1 lead was implanted at the right ventricular (RV) apex, and an LBBAP lead through the interventricular septum. Ventricular fibrillation was induced at implantation in both conventional (RV) and left bundle branch area sensing configurations. The latter was the final sensing configuration, and patients were implanted with a dual-chamber DF-1 ICD connected to the atrial lead (RA port), the LBBAP lead (RV IS-1 port), and the defibrillation lead (RV DF-1 port), the IS-1 pin being capped. Atrioventricular delay was optimized to ensure fusion between LBBAP and native conduction from the right bundle. Patients were followed during 6 months.

RESULTS

No difference between both configurations was observed regarding R-wave sensing in sinus rhythm (p = 0.22), ventricular fibrillation median interval detection (p = 1.00), or total induced episode duration (p = 0.78). LBBAP resulted in a significant reduction of median QRS width from 164 to 126 ms (p = 0.002). Median ventricular sensing significantly improved from 9.7 at implantation to 18.8 mV at 6 months (p = 0.01). Median LVEF also significantly improved from 29 to 44% at 6 months (p = 0.002).

CONCLUSION

Ventricular arrhythmia sensing and defibrillation can be performed via a single LBBAP lead connected to a dual-chamber ICD, and is associated with significant electromechanical reverse remodeling.

CLINICAL TRIAL REGISTRATION NUMBER

NCT05102227 In patients presenting with left bundle branch block and left ventricular systolic dysfunction, a left bundle branch area pacing lead connected to a DF-1 dual-chamber implantable cardioverter-defibrillator provides safe ventricular arrhythmia sensing and efficient electro-mechanical resynchronization.

Impact of signal-averaged electrocardiography findings on appropriate shocks in prophylactic implantable cardioverter defibrillator patients with nonischemic systolic heart failure

BACKGROUND

Appropriate shock therapy is associated with subsequent all-cause death in heart failure (HF) patients who receive an implantable cardioverter defibrillator (ICD) for the primary prevention of sudden cardiac death. To evaluate the impact of signal-averaged electrocardiography (SAECG) findings on appropriate shocks in prophylactic ICD patients with nonischemic systolic HF.

METHODS

We studied 86 patients with nonischemic HF and a left ventricular ejection fraction ≤ 35% who underwent new ICD implantation for the primary prevention of sudden cardiac death. We excluded patients who had a previously implanted permanent pacemaker and patients who received cardiac resynchronization therapy with an ICD. SAECG was performed before implantation. Abnormal SAECG findings were defined if 2 of the following 3 conditions were identified: filtered QRS duration (fQRS) ≥ 114 ms, root-mean-square voltage during the last 40 ms of the fQRS (RMS 40) < 20 μV, and duration of the low-amplitude potentials < 40 μV (LAS 40) > 38 ms; additionally, patients with a QRS complex ≥ 120 ms who met both the RMS 40 and LAS 40 criteria were also considered to have abnormal SAECG findings. The primary outcome was the first occurrence of appropriate shock after implantation of the ICD. The secondary outcomes were the first occurrence of inappropriate shock and all-cause mortality.

RESULTS

Forty-two patients met the criteria for abnormal SAECG findings (49%). During a median follow-up period of 61 months, 17 patients (20%) died, 24 (28%) received appropriate shock therapy, and 19 (22%) received inappropriate shock therapy. There was a significantly higher incidence of appropriate shocks in patients with abnormal SAECG findings than in those with normal SAECG findings (log-rank test, p = 0.025). Multivariate analysis revealed that abnormal SAECG findings were independently associated with the occurrence of appropriate shock (hazard ratio 2.67, 95% confidential interval 1.14-6.26). However, abnormal SAECG findings were not related to inappropriate shock. There was no difference in the incidence of all-cause death between patients with abnormal and normal SAECG findings.

CONCLUSIONS

Our results suggest that abnormal SAECG findings are associated with a high probability of appropriate shocks in prophylactic ICD patients with nonischemic systolic HF.

Physical function, psychological adjustment, and self-efficacy following sudden cardiac arrest and an initial implantable cardioverter defibrillator (ICD) in a social cognitive theory intervention: secondary analysis of a randomized control trial

BACKGROUND

Sudden cardiac arrest (SCA) survivorship results in unique issues in return to physical and psychological function. The purpose of the study was to compare recovery across the first year between SCA survivors and other arrhythmia patients who received a first-time implantable cardioverter defibrillator (ICD) for secondary prevention, participating in a social cognitive theory (SCT) intervention.

METHODS

168 (129 males, 39 females) who received an ICD for secondary prevention (SCA N = 65; other arrhythmia N = 103) were randomized to one of two study conditions: SCT intervention (N = 85) or usual care (N = 83). Outcomes were measured at baseline hospital discharge, 1, 3, 6, & 12 months: (1) Physical Function: Patient Concerns Assessment (PCA), SF-36 (PCS); (2) Psychological Adjustment: State Trait Anxiety (STAI), CES-D depression, SF-36 (MCS); (3) Self-Efficacy: Self-Efficacy (SCA-SE), Self-management Behaviors (SMB), Outcome Expectations (OE). Outcomes were compared over 12 months for intervention condition x ICD indication using general estimating equations.

RESULTS

Participants were Caucasian (89%), mean age 63.95 ± 12.3 years, EF% 33.95 ± 13.9, BMI 28.19 ± 6.2, and Charlson Index 4.27 ± 2.3. Physical symptoms (PCA) were higher over time for SCA survivors compared to the other arrhythmia group (p = 0.04), ICD shocks were lower in SCA survivors in the SCT intervention (p = 0.01); psychological adjustment (MCS) was significantly lower in SCA survivors in the SCT intervention over 6 months, which improved at 12 months (p = 0.05); outcome expectations (OE) were significantly lower for SCA survivors in the SCT intervention (p = 0.008).

CONCLUSIONS

SCA survivors had greater number of physical symptoms, lower levels of mental health and outcome expectations over 12 months despite participation in a SCT intervention. Trial registration Clinicaltrials.gov: NCT04462887.

Utilization of Implantable Cardioverter Defibrillators Among Patients with a Left Ventricular Assist Device: Insights From a National Database

The trends and predictors of implantable cardioverter defibrillator (ICD) use in patients with a durable left ventricular assist device (LVAD) remain uncertain. We used the National Inpatient Sample to identify hospitalizations between 2009 and 2018 in which patients received a new LVAD or had a pre-existing one. Procedure codes were then used to identify hospitalizations in which a new ICD was implanted. In 34,113 hospitalizations for new/replacement LVADs, an ICD was implanted in 1297 (3.8%). The rate of ICD implantation along with an LVAD declined from 2009-2018 (annual percent change: -23.2%; p-trend<0.001). Independent factors associated with concurrent ICD implantation in patients receiving LVAD were younger age, White (compared with Black) race, and in-hospital cardiac arrest. Concurrent ICD implantation was associated with a longer hospital stay (adjusted mean difference: 4.48 days) and higher inflation-adjusted costs (adjusted mean difference: $31,679), but lower in-hospital mortality rates (adjusted odds ratio: 0.29; p<0.001), compared with LVAD placement alone. Amongst 95,583 hospitalizations of patients with a pre-existing LVAD, an ICD was placed in 616 (0.64%). There was no change in the rate of ICD implantation from 2009-2018 in patients with a pre-existing LVAD (annual percent change: -10.34%; p=0.18).

Characteristics and factors associated to patients discharging from hospital without an implantable cardioverter defibrillator after out-of-hospital cardiac arrest

AIMS

Guidelines recommend that in the absence of reversible cause for sudden cardiac arrest (SCA), implantable cardioverter defibrillator (ICD) should be performed to prevent further fatal event. We sought to describe the frequency and characteristics of patients discharged from the hospital without ICD after the SCA in the daily practice.

METHODS AND RESULTS

From 2011 to 2018, all SCAs related to a cardiac cause admitted alive across the 48 hospitals of Great Paris Area were prospectively enrolled. Two investigators thoroughly reviewed each medical report to ensure accuracy of the assigned diagnosis towards identifying the cause of SCA and ICD implantation. Out of the 4314 SCA admitted alive at hospital admission, 1064 cardiac-related SCA survivors were discharged alive from hospital, including 356 patients (33.5%) with an ICD and 708 (66.5%) without. The principal underlying cause of SCA among those discharged without an ICD was acute coronary syndrome (ACS; 602, 85%), chronic coronary artery disease (41, 5.8%), structural non-ischaemic heart disease (48, 6.8%), and non-structural heart disease (17, 2.4%). Among ACS-related SCA, 93.8% (602/642) discharged without an ICD. The unique factor associated with non-ICD implantation in the setting of ACS was immediate coronary angioplasty (odds ratio 4.22, 95% confidence interval 1.86-9.30, P < 0.001).

CONCLUSION

Two-thirds of SCA survivors were discharged without an ICD, mainly in the setting of ACS. The unique factor associated with non-ICD implantation among ACS was immediate coronary angioplasty emphasizing the fact that ACS definition must be precise since associated with ICD implantation or not.

Subcutaneous implantable cardioverter defibrillator after transvenous lead extraction: safety, efficacy and outcome

BACKGROUND

Subcutaneous implantable cardioverter defibrillator (S-ICD) is a suitable alternative for transvenous ICD (TV-ICD) patients who have undergone transvenous lead extraction (TLE). Limited data are available on the outcome of S-ICD patients implanted after TLE. We assessed the safety, efficacy, and outcome of S-ICD implantation after TLE of TV-ICD.

METHODS

The study population consisted of 36 consecutive patients with a median age of 52 (44-66) years who underwent S-ICD implantation after TLE of TV-ICD.

RESULTS

Indications for TLE were infection (63.9%) and lead malfunction (36.1%). During a median follow-up of 31 months, 3 patients (8.3%) experienced appropriate therapy and 7 patients (19.4%) experienced complications including inappropriate therapy (n = 4; 11.1%), isolated pocket erosion (n = 2; 5.5%), and ineffective therapy (n = 1; 2.8%). No lead/hardware dysfunction was reported. Premature device explantation occurred in 4 patients (11%). Eight patients (22.2%) died during follow-up, six of them (75%) because of refractory heart failure (HF). There were no S-ICD-related deaths. Predictors of mortality included NYHA class ≥ 2 (HR 5.05; 95% CI 1.00-26.38; p = 0.04), hypertension (HR 22.72; 95% CI 1.05-26.31; p = 0.02), diabetes (HR 10.64; 95% CI 2.05-55.60; p = 0.001) and ischemic heart disease (HR 5.92; 95% CI 1.17-30.30; p = 0.01).

CONCLUSION

Our study provides evidences on the use of S-ICD as an alternative after TV-ICD explantation for both infection and lead failure. Mortality of S-ICD patients who underwent TV-ICD explantation does not appear to be correlated with the presence of a prior infection, S-ICD therapy (appropriate or inappropriate), or S-ICD complications but rather to worsening of HF or other comorbidities.

Implantable defibrillators in primary prevention of genetic arrhythmias. A shocking choice?

Many previously unexplained life-threatening ventricular arrhythmias and sudden cardiac deaths (SCDs) in young individuals are now recognized to be genetic in nature and are ascribed to a growing number of distinct inherited arrhythmogenic diseases. These include hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (VT), and short QT syndrome. Because of their lower frequency compared to coronary disease, risk factors for SCD are not very precise in patients with inherited arrhythmogenic diseases. As randomized studies are generally non-feasible and may even be ethically unjustifiable, especially in the presence of effective therapies, the risk assessment of malignant arrhythmic events such as SCD, cardiac arrest due to ventricular fibrillation (VF), appropriate implantable cardioverter defibrillator (ICD) interventions, or ICD therapy on fast VT/VF to guide ICD implantation is based on observational data and expert consensus. In this document, we review risk factors for SCD and indications for ICD implantation and additional therapies. What emerges is that, allowing for some important differences between cardiomyopathies and channelopathies, there is a growing and disquieting trend to create, and then use, semi-automated systems (risk scores, risk calculators, and, to some extent, even guidelines) which then dictate therapeutic choices. Their common denominator is a tendency to favour ICD implantation, sometime with reason, sometime without it. This contrasts with the time-honoured approach of selecting, among the available therapies, the best option (ICDs included) based on the clinical judgement for the specific patient and after having assessed the protection provided by optimal medical treatment.

Predictors of primary prevention implantable cardioverter defibrillator use in heart failure with reduced ejection fraction: Impact of the predicted risk of sudden cardiac death and all-cause mortality

Aims

Use of implantable cardioverter‐defibrillators (ICD) for primary prevention of sudden cardiac death (SCD) in heart failure with reduced ejection fraction (HFrEF) is limited. We aimed to investigate barriers to ICD use in HFrEF while considering the predicted risk of mortality and SCD.

Method and results

Patients from the SwedeHF registered in 2011–2018 and with an indication for primary prevention ICD were analysed. The Seattle Proportional Risk and Seattle Heart Failure Models were used to predict the proportional SCD and all‐cause mortality risk, respectively. A multivariable logistic regression model was fitted to identify independent predictors of ICD use/non‐use; Cox regression models to evaluate the interaction between predicted SCD/mortality risk and ICD use for mortality. Of 13 475 patients, only 15.5% had an ICD. Those with higher predicted proportional SCD risk (>45%) had an ∼80% higher likelihood to have an ICD. Other predictors of non‐use were follow‐up in primary versus specialty care, higher comorbidity burden and lower socioeconomic status. ICD use was associated with lower mortality only in patients with higher predicted SCD and lower mortality risk (34% and 37% relative risk reduction for 3‐year all‐cause and cardiovascular mortality, respectively). In this subgroup of patients, underuse of ICD was 81.8%.

Conclusion

In a contemporary registry, only 15.5% of patients with an indication for primary prevention ICD received the device. While a high predicted proportional SCD risk was appropriately linked to ICD use, the lack of specialized follow‐up, higher comorbidity burden, and lower socioeconomic status were major unjustified impediments to implementation. Our findings suggest areas for improving ICD use for primary prevention of SCD in clinical practice.

High defibrillation threshold with right-sided ICD implantation was resolved by a dual coil lead via persistent left superior vena cava

Persistent left superior vena cava (PLSVC) can be problematic when device implantation is scheduled from the left side because of the technical difficulty in delivering leads. Right-sided implantation is an alternative method, but there is a risk of a high defibrillation threshold (DFT). Transvenous implantation of an implantable cardioverter defibrillator (ICD) was scheduled for a 54-year-old man with idiopathic dilated cardiomyopathy and monomorphic non-sustained ventricular tachycardia, but computed tomography revealed the presence of a PLSVC. Right-sided ICD implantation was performed first; however, an ICD shock at 35 J failed to terminate the induced ventricular fibrillation (VF). Re-implantation via the PLSVC by a left subclavian approach with a dual coil lead was performed next. The dual coil right ventricular lead was successfully implanted via the PLSVC, and the induced VF was terminated by a single shock at 25 J. In the present case, the proximal coil was located in the coronary sinus (CS) and it enabled an antero-posterior defibrillation vector across the left ventricle. In addition to the re-location of the ICD generator from the right side to the left side, the new positioning of the proximal coil inside the CS is likely to have contributed to the great improvement of the DFT. .

Secondary prevention implantable cardioverter-defibrillator (ICD) therapy: value in octogenarians

Background

Implantable cardioverter-defibrillator (ICD) therapy is well established for secondary prevention, but studies on the efficacy and safety in elderly patients are still lacking. This retrospective study compared the outcome after ICD implantation between octogenarians and other age groups.

Methods

Data were obtained from a local ICD registry. Patients who received ICD implantation for secondary prevention at our department were included. All-cause mortality, appropriate ICD therapy and acute adverse events requiring surgical intervention were compared between different age groups.

Results

519 patients were enrolled, 34 of whom were aged ≥ 80 years. During the median follow-up of 35 months after ICD implantation 129 patients (annual mortality rate 5.0%) had died, including 16 patients aged ≥ 80 years (annual mortality rate 9.4%). The mortality rate of patients aged ≥ 80 years was significantly higher than that of patients aged ≤ 69 years (p < 0.001), but similar to that of patients aged 70–79 years. Age at the time of ICD implantation was an independent predictor of all-cause mortality (p < 0.001). 29.7% of patients had appropriate ICD therapy with no difference between age groups. Acute adverse events leading to surgical intervention were low (n = 13) and not age-related.

Conclusion

Age is an independent predictor of mortality after ICD implantation for secondary prevention. Mortality rates did not differ significantly between octogenarians and other elderly aged 70–79 years. Appropriate ICD therapy and acute adverse events leading to surgical intervention were not age-related. Implantable cardioverter-defibrillator therapy for secondary prevention seems to be an effective and safe treatment modality in octogenarians.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-02019-2.

Guideline-directed device therapies in heart failure: A clinical practice-based analysis using electronic health record data

Background

Guideline-directed device therapies (GDDT) improve outcomes for eligible patients with heart failure (HF) with reduced ejection fraction (HFrEF). Utilization rates of device therapies in HFrEF after the 2012 ACCF/AHA/HRS Focused Update for Device-based Therapies of Cardiac Rhythm Abnormalities have not been well studied.

Objective

Characterize the use of GDDT in newly indicated HFrEF patients from 2012 to 2019 using aggregated electronic health record (EHR) data.

Methods

Computable phenotyping algorithms for implantable cardioverter defibrillator/cardiac resynchronization therapy-defibrillator (ICD/CRT-D) indications from the GuideLine Indications Detected in EHR for Heart Failure program (GLIDE-HF) used diagnoses, procedures, measures, prescriptions, and the output of natural language processed provider notes from de-identified Optum® EHR data. Patients had a diagnosis of HF, dilated cardiomyopathy, or prior infarct, and were included if they had HFrEF with >1 year of records prior to a new Class 1 or Class 2a indication for an ICD or cardiac resynchronization therapy with defibrillator (CRT-D) from 2012 to 2019.

Results

Records showed 137,476 HFrEF patients were newly indicated for an ICD or CRT-D. GDDT was used in 14,892 of 36,358 (41.0%) CRT-D indicated patients and in 14,904 of 101,118 (14.7%) ICD-indicated patients. While GDDT use was low, 95.7% had echocardiography and 92.1% had prescriptions for beta-blockers or angiotensin-converting enzyme/angiotensin-receptor blockers medications.

Conclusions

In this modern cohort of HF patients, a large proportion of eligible patients did not receive ICDs or CRT-Ds, while frequently receiving other indicated cardiovascular interventions and treatments.

Evaluating Common NOS1AP Variants in Patients with Implantable Cardioverter Defibrillators for Secondary Prevention : Evaluating SNPs in NOS1AP

BACKGROUND

Recent research has found that single nucleotide polymorphisms (SNPs) in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene are associated with altered QT intervals and sudden cardiac death (SCD). However, the clinical utility and implications of NOS1AP SNPs remain unclear. Thus, this study aimed to explore the influence of NOS1AP SNPs in patients with implantable cardioverter defibrillator (ICD) for secondary prevention.

METHODS

We conducted a case-control study to evaluate the most studied SNPs in NOS1AP (rs12143842, rs10494366, rs12567209, and rs16847548) in patients with ICD for secondary prevention. Patients were followed for up to 36 months from the time of ICD implantation. ICD interrogation data at 3 and 12 months, including rapid ventricular arrhythmia episodes and appropriate therapies, were then analyzed.  RESULTS: A significant association was observed between rs10494366 and ICD recipients who experienced appropriate therapies. After a mean follow-up time of 31.70 ± 9.15 months, we detected significant differences among the three rs10494366 genotype groups in the distribution of ICD shocks and appropriate therapies, as well as in the correlation of rs10494366 and ICD shocks. According to Kaplan-Meier and Cox regression analyses, patients with the TT genotype had a higher risk of SCD than those with the GG genotype.

CONCLUSIONS

The present study revealed that NOS1AP SNP rs10494366 was associated with appropriate therapies. Specifically, the TT genotype increased ICD shocks and SCD risk in patients with ICD for secondary prevention for the first time.

Subcutaneous ICD for more and transvenous ICD for few?!

Implantable cardioverter defibrillators (ICDs) have been shown to reduce the risk of sudden cardiac death in primary or secondary prevention with thousands of ICDs implanted every year worldwide. Whilst ICD are more commonly implanted transvenously (TV), this approach carries high risk of peri- and post-procedural complications. Subcutaneous ICD (S-ICD) have been introduced to overcome the intravascular complications of TV system by placing all metalware outside the chest cavity for those with an indication for a defibrillator and no pacing requirements. In conclusion, a review of the current guidelines recommendations regarding S-ICD may be needed considering the emerging evidence which shows high efficacy and safety with contemporary devices and programming algorithms. A stronger recommendation may be developed for selective patients who have an indication for single-chamber ICD in the absence of negative screening, recurrent monomorphic ventricular tachycardia, cardiac resynchronization therapy, or pacemaker indication. These criteria encapsulate a large proportion (around 70%!) of all ICD eligible patients.

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.

Effect of implantable cardioverter-defibrillators in patients with non-ischaemic systolic heart failure and concurrent coronary atherosclerosis

Aims

Prophylactic implantable cardioverter‐defibrillators (ICD) reduce mortality in patients with ischaemic heart failure (HF), whereas the effect of ICD in patients with non‐ischaemic HF is less clear. We aimed to investigate the association between concomitant coronary atherosclerosis and mortality in patients with non‐ischaemic HF and the effect of ICD implantation in these patients.

Methods and results

Patients were included from DANISH (Danish Study to Assess the Efficacy of Implantable Cardioverter Defibrillators in Patients with Non‐Ischaemic Systolic Heart Failure on Mortality), randomizing patients to ICD or control. Study inclusion criteria for HF were left ventricular ejection fraction ≤ 35% and increased levels (>200 pg/mL) of N‐terminal pro‐brain natriuretic peptide. Of the 1116 patients from DANISH, 838 (75%) patients had available data from coronary angiogram and were included in this subgroup analysis. We used Cox regression to assess the relationship between coronary atherosclerosis and mortality and the effect of ICD implantation. Of the included patients, 266 (32%) had coronary atherosclerosis. Of these, 216 (81%) had atherosclerosis without significant stenoses, and 50 (19%) had significant stenosis. Patients with atherosclerosis were significantly older {67 [interquartile range (IQR) 61–73] vs. 61 [IQR 54–68] years; P < 0.0001}, and more were men (77% vs. 70%; P = 0.03). During a median follow‐up of 64.3 months (IQR 47–82), 174 (21%) of the patients died. The effect of ICD on all‐cause mortality was not modified by coronary atherosclerosis [hazard ratio (HR) 0.94; 0.58–1.52; P = 0.79 vs. HR 0.82; 0.56–1.20; P = 0.30], P for interaction = 0.67. In univariable analysis, coronary atherosclerosis was a significant predictor of all‐cause mortality [HR, 1.41; 95% confidence interval (CI), 1.04–1.91; P = 0.03]. However, this association disappeared when adjusting for cardiovascular risk factors (age, gender, diabetes, hypertension, smoking, and estimated glomerular filtration rate) (HR 1.05, 0.76–1.45, P = 0.76).

Conclusions

In patients with non‐ischaemic systolic heart failure, ICD implantation did not reduce all‐cause mortality in patients either with or without concomitant coronary atherosclerosis. The concomitant presence of coronary atherosclerosis was associated with increased mortality. However, this association was explained by other risk factors.

Underrepresentation of women in implantable cardioverter defibrillator trials

There are sex differences in the epidemiology and presentation of ventricular arrhythmias. Sudden cardiac death (SCD) is less common in women than in men. Women have been under-represented in implantable cardioverter defibrillator (ICD) trials evaluating the benefit of ICD therapy for primary and secondary prevention of SCD. Following ICD implantation, women are less likely to experience appropriate ICD therapy for ventricular arrhythmias, consistent with epidemiological findings of a lower rate of SCD in women. Sex differences in ICD implantation rates have also been noted for primary and secondary prevention of SCD in registries and large observational cohort studies. Reasons for these differences are unclear. Age and comorbidities at the time of presentation may be partially responsible, although sex bias, patient preference, or contribution of social determinants of health cannot be excluded. There are many unanswered questions regarding reasons for sex differences in ICD usage and under-representation of women in clinical device trials. Additional investigation is needed to better understand these differences to improve outcome of all patients who are at risk for sudden cardiac arrest.

Transcranial direct current stimulation in patient with J wave syndrome and implantable cardioverter defibrillator

J wave syndrome is a spectrum of proarrhythmic disorders including Brugada syndrome and early repolarization syndrome, that are prone to ventricular fibrillation and sudden cardiac death. In this case report we present a patient with Early repolarization syndrome and aborted sudden cardiac death complicated with cognitive impairment. We also investigated whether performing transcranial direct current stimulation to target his cognitive impairment, interfered with the function of his implantable cardioverter defibrillator. This article is protected by copyright. All rights reserved.

Feasibility of adenosine stress cardiovascular magnetic resonance perfusion imaging in patients with MR-conditional transvenous permanent pacemakers and defibrillators

BACKGROUND

The use of stress perfusion-cardiovascular magnetic resonance (CMR) imaging remains limited in patients with implantable devices. The primary goal of the study was to assess the safety, image quality, and the diagnostic value of stress perfusion-CMR in patients with MR-conditional transvenous permanent pacemakers (PPM) or implantable cardioverter-defibrillators (ICD).

METHODS

Consecutive patients with a transvenous PPM or ICD referred for adenosine stress-CMR were enrolled in this single-center longitudinal study. The CMR protocol was performed using a 1.5 T system according to current guidelines while all devices were put in MR-mode. Quality of cine, late-gadolinium-enhancement (LGE), and stress perfusion sequences were assessed. An ischemia burden of ≥ 1.5 segments was considered significant. We assessed the safety, image quality and the occurrence of interference of the magnetic field with the implantable device. In case of ischemia, we also assessed the correlation with the presence of significant coronary lesions on coronary angiography.

RESULTS

Among 3743 perfusion-CMR examinations, 66 patients had implantable devices (1.7%). Image quality proved diagnostic in 98% of cases. No device damage or malfunction was reported immediately and at 1 year. Fifty patients were continuously paced during CMR. Heart rate and systolic blood pressure remained unchanged during adenosine stress, while diastolic blood pressure decreased (p = 0.007). Six patients (9%) had an ischemia-positive stress CMR and significant coronary stenoses were confirmed by coronary angiography in all cases.

CONCLUSION

Stress perfusion-CMR is safe, allows reliable ischemia detection, and provides good diagnostic value.

Three-Dimensional Analysis of the In Vivo Motion of Implantable Cardioverter Defibrillator Leads

Better understanding of the lead curvature, movement and their spatial distribution may be beneficial in developing lead testing methods, guiding implantations and improving life expectancy of implanted leads.

OBJECTIVE

The aim of this two-phase study was to develop and test a novel biplane cine-fluoroscopy-based method to evaluate input parameters for bending stress in leads based on their in vivo 3D motion using precisely determined spatial distributions of lead curvatures. Potential tensile, compressive or torque forces were not subjects of this study.

METHODS

A method to measure lead curvature and curvature evolution was initially tested in a phantom study. In the second phase using this model 51 patients with implanted ICD leads were included. A biplane cine-fluoroscopy recording of the intracardiac region of the lead was performed. The lead centerline and its motion were reconstructed in 3D and used to define lead curvature and curvature changes. The maximum absolute curvature C_max during a cardiac cycle, the maximum curvature amplitude C_amp and the maximum curvature C_max@amp at the location of C_amp were calculated. These parameters can be used to characterize fatigue stress in a lead under cyclical bending.

RESULTS

The medians of C_amp and C_max@amp were 0.18 cm^-1 and 0.42 cm^-1, respectively. The median location of C_max was in the atrium whereas the median location of C_amp occurred close to where the transit through the tricuspid valve can be assumed. Increased curvatures were found for higher slack grades.

CONCLUSION

Our results suggest that reconstruction of 3D ICD lead motion is feasible using biplane cine-fluoroscopy. Lead curvatures can be computed with high accuracy and the results can be implemented to improve lead design and testing.