Role Of Implantable Cardioverter Defibrillator Research Articles

Arrhythmias and Device Therapies in Cardiac Amyloidosis.

Cardiac amyloidosis is caused by amyloid fibrils that deposit in the myocardial interstitium, causing restrictive cardiomyopathy and eventually death. The electromechanical, inflammatory, and autonomic changes due to amyloid deposition result in arrhythmias. Atrial fibrillation is by far the most common arrhythmia. The rate control strategy is generally poorly tolerated due to restrictive filling physiology and heart rate dependance, favoring adoption of the rhythm control strategy. Anticoagulation for stroke prophylaxis is warranted, irrespective of CHA2DS2-VASc score in patients with a favorable bleeding profile; data on left appendage closure devices are still insufficient. Ventricular arrhythmias are also not uncommon, and the role of implantable cardioverter-defibrillator in cardiac amyloidosis is controversial. There is no evidence of improvement in outcomes when used for primary prevention in these patients. Bradyarrhythmia is most commonly associated with sudden cardiac death in cardiac amyloidosis. Pacemaker implantation can help provide symptomatic relief but does not confer mortality benefit.

Advanced heart failure: a contemporary approach.

Advanced heart failure (HF) is defined as the persistence of severe symptoms despite the use of optimized medical, surgical, and device therapies. These patients require timely advanced treatments, such as heart transplantation or long-term mechanical circulatory support (MCS). Inotropic agents are often used to reduce congestion and increase cardiac output, while renal replacement therapy may be beneficial if necessary. Cardiac resynchronization therapy has clear benefits in patients with HF with reduced ejection fraction, particularly with left bundle branch block (QRS duration > 130 ms). The role of implantable cardioverter-defibrillators in advanced HF patients requires further investigation considering the introduction of novel HF medications. In selected patients with significant secondary mitral regurgitation, transcatheter edge-to-edge repair can help delay heart transplantation or long-term MCS. In later stages, the appropriateness of heart transplantation should be evaluated, and the use of short- or long-term MCS may be considered. A multidisciplinary HF management program is crucial for patients with advanced HF. Recent treatment advances, including drugs, devices, and MCS, have broadened the options available to patients with advanced HF and this trend is expected to continue.

Declining Risk of Sudden Cardiac Death in Heart Failure: Fact or Myth?

The notion that the risk of sudden cardiac death (SCD) in patients with heart failure (HF) is declining seems to be gaining traction. Numerous editorials and commentaries have suggested that SCD, specifically arrhythmic SCD, is no longer a significant risk for patients with HF on guideline-directed medical therapy. In this review, we question whether the risk of SCD has indeed declined in HF trials and in the real world. We also explore whether, despite relative risk reductions, the residual SCD risk after guideline-directed medical therapy still suggests a need for implantable cardioverter defibrillator therapy. Among our arguments is that SCD has not decreased in HF trials, nor in the real world. Moreover, we argue that data from HF trials, which have not adhered to guideline-directed device therapy, do not obviate or justify delays to implantable cardioverter defibrillator therapy. In this context, we underline the challenges of translating the findings of HF randomized, controlled trials of guideline-directed medical therapy to the real world. We also make the case for HF trials that adhere to current guideline-directed device therapy so that we can better understand the role of implantable cardioverter defibrillators in chronic HF.

Efficacy and safety of the ICD in patients with catecholaminergic polymorphic ventricular tachycardia

Abstract Background Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a potentially fatal genetic arrhythmia syndrome and, despite optimal beta-blocker (BB) therapy, patients often experience life-threatening arrhythmic events (LAE). The role of implantable cardioverter defibrillators (ICD) on reducing mortality in patients with CPVT is debated. Purpose 1) To assess the survival benefit of ICD in the overall CPVT population; 2) to investigate the benefit-to-harm ratio in the population of CPVT patients carriers of ICD. Methods We followed-up consecutive patients with genetically-proven CPVT, treated with optimal BB mono-therapy. The probability of surviving at the occurrence of a first LAE (defined as: sudden cardiac death, aborted cardiac arrest or hemodynamically non-tolerated ventricular tachycardia) during BB mono-therapy was compared between ICD carriers and non-ICD carriers. In the cohort of ICD carriers, we assessed the rate of a first major complication (i.e., a complication requiring surgical intervention) and we calculated the benefit-to-harm ratio of ICD (defined as rate of appropriate shocks on LAE over rate of major complications). Results We enrolled 228 CPVT patients with a pathogenic RYR2 (n=216) or CASQ2 (n=12) mutation, of whom 87 (38%) had an ICD implanted. Overall, during 1,558 person-years of follow-up, 31/228 (14%) patients experienced a first LAE on BB mono-therapy (annual LAE rate 2.0%, 95% CI: 1.4–2.8%). Of the 31 individuals who experienced an LAE, 21 patients had an ICD when the LAE occurred, and all survived after ICD intervention. Of the remaining 10 patients who were not carriers of an ICD, 6/10 (60%) survived after external defibrillation or spontaneous arrhythmia termination, while 4/10 (40%) died suddenly. The probability of surviving at the occurrence of a first LAE in BB mono-therapy was thirty-fold higher (Odds Ratio: 30.0, 95% CI: 1.4–629.0; p=0.029) in patients with an ICD, as compared to patients without an ICD. Overall, 15/87 (17%) patients with an ICD experienced a first major complication over 602 person-years of follow-up (2.5% per year, 95% CI: 1.4%-4.1%). Importantly, no patient died for a pro-arrhythmic effect or complications related to ICD. Comparing the rate of major complications to the rate of appropriate ICD shocks on LAE (LAE rate 4.7% per year, 95% CI: 3.1–7.0%), the benefit-to-harm ratio was 1.9, thus favouring the benefit of ICD therapy. Conclusions In our population, ICD therapy conferred a significant survival benefit in patients with CPVT at the occurrence of a first LAE. Overall, the benefit of ICD implant outweighed the harm, as shown by almost two times greater benefit-to-harm ratio. This study provides evidence supporting ICD implantation in patients with high-risk CPVT. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ricerca Corrente Funding Scheme of the Italian Ministry of Health

Role of Implantable Cardioverter Defibrillator in Heart Failure With Contemporary Medical Therapy.

Implantable cardioverter defibrillator therapy is indicated in a subset of patients with heart failure with reduced ejection as primary prevention for sudden cardiac death. The advent of novel medical therapies including mineralocorticoid receptor antagonists, angiotensin receptor blocker/neprilysin inhibitors, and sodium-glucose transporter 2 inhibitor in the past 2 decades has revolutionized heart failure with reduced ejection management. Current guideline-directed medical therapy has reduced all-cause mortality and sudden cardiac death and confers a considerable improvement in left ventricular ejection fraction over a short period of time. However, there is limited evidence at present to suggest whether implantable cardioverter defibrillator therapy continues to have the same benefit in sudden cardiac death prevention at current left ventricular ejection fraction cutoff indications for patients on contemporary guideline-directed medical therapy for heart failure with reduced ejection. In this review, the authors propose in lieu of current evidence that it is reasonable to reevaluate indications for implantable cardioverter defibrillator therapy in patients on contemporary guideline-directed medical therapy for heart failure with reduced ejection.

Outcomes of Patients With Catecholaminergic Polymorphic Ventricular Tachycardia Treated With β-Blockers

Patients with catecholaminergic polymorphic ventricular tachycardia (CPVT) may experience life-threatening arrhythmic events (LTAEs) despite β-blocker treatment. Further complicating management, the role of implantable cardioverter defibrillator (ICD) in CPVT is debated. To investigate the long-term outcomes of patients with RYR2 CPVT treated with β-blockers only and the cost to benefit ratio of ICD. This prospective cohort study conducted from January 1988 to October 2020 with a mean (SD) follow-up of 9.4 (7.5) years included patients who were referred to the Molecular Cardiology Clinics of ICS Maugeri Hospital, Pavia, Italy. Participants included consecutive patients with CPVT who were carriers of a pathogenic or likely pathogenic RYR2 variant with long-term clinical follow-up. Treatment with selective and nonselective β-blocker only and ICD implant when indicated. The main outcome was the occurrence of the first LTAE while taking a β-blocker. LTAE was defined as a composite of 3 hard end points: sudden cardiac death, aborted cardiac arrest, and hemodynamically nontolerated ventricular tachycardia. The cohort included 216 patients with RYR2 CPVT (121 of 216 female [55%], median [IQR] age 14, [9-30] years). During a mean (SD) follow-up of 9.4 (7.5) years taking β-blockers only, 28 of 216 patients (13%) experienced an LTAE (annual rate, 1.9%; 95% CI, 1.3-2.7). In multivariable analysis, experiencing either an LTAE (hazard ratio [HR], 3.3; 95% CI, 1.2-8.9; P = .02) or syncope before diagnosis (HR, 4.5; 95% CI, 1.8-11.1; P = .001) and carrying a C-terminal domain variant (HR, 18.1; 95% CI, 4.1-80.8; P < .001) were associated with an increased LTAE risk during β-blocker therapy only. The risk of LTAE among those taking selective β-blockers vs nadolol was increased 6-fold (HR, 5.8; 95% CI, 2.1-16.3; P = .001). Conversely, no significant difference was present between propranolol and nadolol (HR, 1.8; 95% CI, 0.4-7.3; P = .44). An ICD was implanted in 79 of 216 patients (37%) who were followed up for a mean (SD) of 8.6 (6.3) years. At the occurrence of LTAE, ICD carriers were more likely to survive (18 of 18 [100%]) than non-ICD carriers (6 of 10 [60%]; P = .01). In this cohort study, selective β-blockers were associated with a higher risk of LTAE as compared with nadolol. Independently from treatment, LTAE and syncope before diagnosis and C-terminal domain variants identified patients at higher risk of β-blocker failure, and the ICD was associated with reduced mortality in high-risk patients with CPVT.

The validity of current implantable cardioverter-defibrillator guidelines in a real-world population of adults with congenital heart disease: A single-center experience

AimsSudden cardiac death (SCD) is a major cause of mortality in adults with congenital heart disease (ACHD). The role of implantable cardioverter-defibrillator (ICDs) in preventing SCD has been established, however, robust, clinical evidence-based guidelines are lacking in ACHD. The aim of this study was to evaluate the ICD guidelines in ACHD patients. Methods and ResultsA total of 131 ACHD patients (male: n = 96 (73.3%), mean age: 42.8 ± 14.7 years, mean follow-up: 40.9 ± 28.3 months) undergoing ICDs implantation between 2010 and 2017 were reviewed. Sixty-nine patients (52.6%) received ICDs for a primary prevention indication. 122 (93.3%) patients had congenital heart disease of moderate to severe complexity. CRT-D (implantable cardiac resynchronization defibrillator) was implanted in 55 (42.0%) patients. During follow-up, 23 patients (17.6%) received appropriate ICD therapy. According to the current guideline (PACES/HRS 2014), 84 (64.1%), 8 (6.1%), and 39 (29.8%) could be classified as Class Ⅰ, Class Ⅱa, and Class Ⅱb indication, respectively. Compared to patients with Class Ⅱa and IIb indication, those with Class Ⅰ indication received more appropriate therapy (P = 0.030). Multivariate analysis showed that age (per 10-years decrease; P = 0.015, HR 1.254 CI; 1.045–1.505) and creatinine (per 100-μmol/L increase; P = 0.019, HR 1.555 CI; 1.076–2.247) were associated with appropriate therapy. ConclusionImplantation of ICDs for preventing SCD based on current guidelines is reasonable. For patients with a borderline indication, younger age and renal dysfunction may aid in the selection of ICDs candidates.

614 Implantable cardiac monitors predict arrhythmic events in post-infarction patients with mildly reduced left ventricular ejection fraction

Abstract Aims Complications of acute myocardial infarction (MI) can be life-threatening leading to sudden cardiac death. While guidelines recommend prompt revascularization and prolonged intensive care hospitalization, predictors of major adverse cardiovascular outcomes are yet poorly understood. The role of implantable cardioverter-defibrillators, even in cases of non-sustained arrhythmias is still debated. To date, it is unknown how to follow-up patients with mild cardiac dysfunction after MI. Implantable cardiac monitors (ICMs) can be helpful for stratifying patients in the early discharge period, and remote monitoring might speed up arrhythmia recognition and treatment. We investigated the role of remote monitoring of ICMs to detect arrhythmic events in post-MI patients without overt cardiac dysfunction. Methods and results We enrolled 13 patients (9 males; 69.8 years) after either ST-segment (N = 7) or non-ST-segment elevation (N = 6) MI with a left ventricular ejection fraction (LVEF) &amp;gt;35%, admitted to our coronary care unit for urgent revascularization between September 2019 and September 2021. Twelve patients underwent percutaneous myocardial revascularization, whereas one was treated with medical therapy only. All patients received an ICM during hospitalization according to echo and EKG parameters. We considered LVEF ≤ 40% as sole risk factor or LVEF between 40% and 50% in addition to either PQ length prolongation, or QRS widening, or pathologic heart rate variability, or non-sustained ventricular tachycardia/paroxysmal advanced second degree atrioventricular block. Patients with multiple revascularization procedures and several hospital admissions were excluded. Implanted ICM were frequently monitored both remotely and in-office when required. During follow-up, brady- and tachy-arrhythmias were recorded in four patients (30.8%). The remote monitoring of the ICM documented new-onset atrial fibrillation, high-degree atrioventricular block, severe bradycardia, and sustained ventricular tachycardia. Three patients required hospitalization and upgrade of the implanted device with pacemakers and cardioverter/defibrillator. For arrhythmic risk stratification, patients were divided into two subgroups; group A included patients with LVEF 40% associated with heart rate &amp;gt; 60 b.p.m., PQ length &amp;gt;160 ms and QRS width &amp;gt;86 ms (N = 4); group B included patients with EF 41%/50%, PQ length &amp;lt;159 and QRS width &amp;lt;85 ms (N = 10). First group experienced more advanced rhythm disorders than group B (P &amp;lt; 0.05). Device implantation was significantly higher in group A (P &amp;lt; 0.05%). Conclusions OFF-label implementation of ICMs coupled with remote device monitoring may be effective for early detection of serious adverse cardiac rhythm alterations in patients after MI and LVEF higher than 35%. Further monitoring is ongoing for assessing the occurrence of multiple arrhythmias or their increased occurrence.

Arrhythmic Sudden Cardiac Death and the Role of Implantable Cardioverter-Defibrillator in Patients with Cardiac Amyloidosis-A Narrative Literature Review.

Cardiac amyloidosis (CA) is considered to be associated with an increased risk of sudden cardiac death (SCD) due to ventricular tachyarrhythmias and electromechanical dissociation. However, current arrhythmic risk stratification and the role of an implantable cardioverter-defibrillator (ICD) for primary prevention of SCD remains unclear. This article provides a narrative review of the literature on electrophysiological abnormalities in the context of ventricular arrhythmias in patients with CA and the role of ICD in terms of survival benefit in this group of patients.

Fusion Cardiac Resynchronization Therapy in an LVAD Patient from Two Devices and Crossing Leads

<h3>Introduction</h3> Cardiac implanted electronic devices (CIEDs) have significantly improved the survival and quality of life in heart failure patients. The role of implantable cardioverter defibrillators (ICD) and cardiac resynchronization therapy (CRT) in patients with a left ventricular assist device (LVAD) has not been well defined. CIED procedures come at a price of venous access problems, lead malfunctions and pocket complications. This requires creative approaches to tackle CIED related issues in LVAD patients. <h3>Case Report</h3> Here we describe the clinical course of a 67 year old patient with an LVAD as destination therapy. The heart failure etiology was a non-ischemic cardiomyopathy due to sarcoidosis and he was pacing dependent due to a total atrioventricular block. The patient had an ICD due to recurrent monomorphic ventricular tachycardias and a CRT indication due to previous deterioration of (right sided) heart failure in the temporary absence of biventricular pacing. He recently had a pump thrombosis which was treated medically as he was deemed too frail to undergo a pump exchange. The anticoagulation regimen consisted of a vitamin K antagonist (INR 2.5-3.0) and clopidogrel 75mg o.d.. The patient was admitted for a pulse generator exchange due to low battery voltage. We were confronted with impeding right ventricular lead failure and bilateral venous access problems due to chronic subclavian vein occlusions in a patient with 5 transvenous leads, therapeutic anticoagulation and pronounced thoracic collaterals (Fig 1). Several strategies were considered - venous angioplasty, contralateral lead tunneling and epicardial lead implantation. We sought for a creative solution to deliver biventricular fusion pacing with the existing leads from two contralateral pulse generators. This provided the least invasive solution to deliver effective CRT. <h3>Summary</h3> This case illustrates the complexity of CIED related decision making in pacing dependent LVAD patients, particularly those with an ICD and CRT indication.

Role of implantable cardioverter-defibrillator in patients awaiting heart transplant in the continuous-flow left ventricular assist device era.

Implantable cardioverter-defibrillators (ICDs) have been shown to have survival advantage in advanced heart failure patients. Few studies have evaluated the role of ICDs in patients supported with continuous-flow left ventricular assist devices (CFVADs). We aimed to evaluate the impact of ICD and CFVAD on heart transplant (HTx) waiting list survival. We queried the United Network for Organ Sharing (UNOS) thoracic transplant database between years 2007 and 2016 for patients aged ≥ 18 years listed for HTx. Patients receiving devices other than CFVAD were excluded. Patients were divided into groups-with and without CFVAD and further subdivided into groups-with and without ICD use. Kaplan-Meier curves were used to evaluate the survival outcomes. There were 34860 patients listed for HTx during study period of which 11481 (32%) had a CFVAD and 26139 (75%) had an ICD. Within CFVAD group, patients with ICD were older, more likely male, with higher creatinine and listed as UNOS status 1A. In the No-CFVAD group, 1-year waitlist survival was significantly better with ICD use (81% vs. 73%, P < .0001); however, in CFVAD patients, 1-year survival with ICD use was comparable to No-ICD use (95% vs. 94%, P = .1). Use of ICD is associated with significantly better heart transplant waitlist survival in patients not supported by CFVAD. In patients supported with CFVAD, the ICD does not offer additional survival benefit.

Abstract 16465: Mode of Death and Outcomes of Implantable Cardioverter Defibrillators in Transthyretin Cardiac Amyloidosis

Introduction: Patients with transthyretin cardiac amyloidosis (ATTR-CM) may have higher risk of sudden cardiac death yet the role of implantable cardioverter defibrillators (ICD) remains poorly defined. We report our experience with ICDs in a cohort with ATTR-CM. Methods: A single center observational cohort study of patients who had been seen at our Amyloidosis Center with either wild-type or hereditary ATTR-CM diagnosed between 2005-2019. ICD implant was at discretion of treating cardiologists. Device data was obtained from record review. Results: Ninety-seven patients with ATTR-CM (mean age 71.4±11 years, 89.7% male) had mean follow-up 2.2±1.9 years. Twenty-one patients (21.6%) got ICD - 19 for primary prevention and 2 for secondary prevention - with cumulative 137 interrogations over mean 2.0±2.7 years of device follow-up. In patients with primary prevention ICD, 1 patient got 2 inappropriate shocks - both for 1 episode of atrial flutter in the VT therapy zone; 1 patient got appropriate ATP on 3 occasions. In those with secondary prevention ICD, 1 patient got 15 appropriate shocks for 3 discrete episodes of VT storm; the other got ATP for 1 episode of monomorphic VT. In patients without ICD, 101 ambulatory monitors were reviewed (cumulative 12,313 hours) without sustained ventricular arrhythmia. In this group, 13/76 met at least a class IIB criterion for ICD per current guidelines. EF was higher in those without ICD versus with primary prevention ICD (45.0±13.9 vs 33.4±15.1 %, p=&lt;0.01). Death was seen with similar frequency in those with primary prevention ICD and those without ICD (p=0.60) and mode of death did not vary between them (Table 1). Conclusions: Patients with ATTR-CM and primary prevention ICD have low rates of appropriate device therapy without differing in mode of death compared to those with no ICD. Use of ICD for secondary prevention was uncommon but all patients got appropriate device therapy. Further study on ICDs in ATTR-CM is needed to inform best care.

The role of implantable cardioverter-defibrillators in asymptomatic patients with left ventricular dysfunction.

The role of implantable cardioverter-defibrillators in asymptomatic patients with left ventricular dysfunction.

Current Review of Implantable Cardioverter Defibrillator Use in Patients With Left Ventricular Assist Device.

While use of implantable cardioverter defibrillator (ICD) in patients with heart failure (HF) and reduced ejection fraction is recommended, their role in patients with left ventricular assist device (LVAD) remains controversial, especially with continuous flow (CF) devices. Ventricular arrhythmias (VA) in LVAD patients are frequent and associated with worse outcomes, especially postoperatively. Data on the role of ICDs in LVAD patients are scarce, based on case reports or small retrospective series. While the majority of LVAD patients currently have an ICD, it seems that some might not derive any benefit, with additional risks in terms of inappropriate shocks, psychological distress, and infections. Some CF-LVAD patients are at high risk of VA and hemodynamic collapse; under those circumstances, an ICD might provide benefits. A randomized-controlled trial of routine ICD implantation in CF-LVAD would be needed to clarify their impact on survival in low risk patients.

Mitral Valve Prolapse, Ventricular Arrhythmias, and Sudden Death.

Despite a 2% to 3% prevalence of echocardiographically defined mitral valve prolapse (MVP) in the general population, the actual burden, risk stratification, and treatment of the so-called arrhythmic MVP are unknown. The clinical profile is characterized by a patient, usually female, with mostly bileaflet myxomatous disease, mid-systolic click, repolarization abnormalities in the inferior leads, and complex ventricular arrhythmias with polymorphic/right bundle branch block morphology, without significant regurgitation. Among the various pathophysiologic mechanisms of electrical instability, left ventricular fibrosis in the papillary muscles and inferobasal wall, mitral annulus disjunction, and systolic curling have been recently described by pathological and cardiac magnetic resonance studies in sudden death victims and patients with arrhythmic MVP. In addition, premature ventricular beats arising from the Purkinje tissue as ventricular fibrillation triggers have been documented by electrophysiologic studies in MVP patients with aborted sudden death. The genesis of malignant ventricular arrhythmias in MVP probably recognizes the combination of the substrate (regional myocardial hypertrophy and fibrosis, Purkinje fibers) and the trigger (mechanical stretch) eliciting premature ventricular beats because of a primary morphofunctional abnormality of the mitral valve annulus. The main clinical challenge is how to identify patients with arrhythmic MVP (which imaging technique and in which patient) and how to treat them to prevent sudden death. Thus, there is a necessity for prospective multicenter studies focusing on the prognostic role of cardiac magnetic resonance and electrophysiologic studies and on the therapeutic efficacy of targeted catheter ablation and mitral valve surgery in reducing the risk of life-threatening arrhythmias, as well as the role of implantable cardioverter defibrillators for primary prevention.

Implantable Cardioverter-Defibrillators in Heart Transplant Recipients with Allograft Failure

Purpose Sudden cardiac death may occur in the setting of acute rejection or later in patients with allograft vasculopathy. The role of implantable cardioverter-defibrillators (ICDs) in heart transplant recipients with allograft failure is unknown. Methods We analyzed the United Network for Organ Sharing registry between January 2008 and March 2018 to include adults ≥18 who had undergone heart transplantation and were listed for retransplantation for the indication of allograft failure. Results Between January 2008 and March 2018, 1201 heart transplant recipients were re-listed for transplant of whom 229 (19%) had an ICD. Indications for re-listing included coronary artery disease (n = 699, 58%), primary graft failure (n = 188, 15.7%), chronic rejection (n = 141, 11.7%), acute rejection (n = 60, 5.0%), non-specific reason (n = 57, 4.7%), restrictive or constrictive disease (n = 49, 4.1%), and hyperacute rejection (n = 7, 0.6%). Allograft failure patients with ICDs were younger than those without (47.3 vs 43.5 years, p Conclusion Approximately 1 in 5 heart transplant recipients re-listed for primary allograft failure received an ICD. The use of ICDs does not appear to be associated with increased waitlist survival. More research is needed regarding the role of ICDs in this unique population.

SPONTANEOUS CORONARY ARTERY DISSECTION AND INCIDENT VENTRICULAR ARRHYTHMIAS: FREQUENCY, CLINICAL CHARACTERISTICS, AND OUTCOMES

The role of implantable cardioverter-defibrillators (ICDs) for secondary prevention is uncertain for spontaneous coronary artery dissection (SCAD) patients presenting with ventricular tachycardia/ventricular fibrillation (VT/VF). A retrospective cohort study was performed of 488 consecutive SCAD

Primary prevention with the implantable cardioverter-defibrillator in high-risk long-QT syndrome patients.

Prospective data regarding the role of implantable cardioverter-defibrillator (ICD) for the primary prevention of sudden cardiac death in patients with long QT syndrome (LQTS) is scarce. Herein, we explore the prospective Rochester LQTS ICD registry to assess the risk for appropriate shock in primary prevention in a real-world setting. We studied 212 LQTS patients that had ICD implantation for primary prevention. Best-subsets proportional-hazards regression analysis was used to identify clinical variables that were associated with the first appropriate shock. Conditional models of Prentice, Williams, and Peterson were utilized for the analysis of recurrent appropriate shocks. During a median follow-up of 9.2 ± 4.9 years, there were 42 patients who experienced at least one appropriate shock and the cumulative probability of appropriate shock at 8 years was 22%. QTc ≥ 550 ms [hazard ratio (HR) 3.94, confidence interval (CI) 2.08-7.46; P < 0.001) and prior syncope on β-blockers (HR 1.92, CI 1.01-3.65; P = 0.047) were associated with increased risk of appropriate shock. History of syncope while on β-blocker treatment (HR 1.87, CI 1.28-2.72; P = 0.001), QTc 500-549 ms (HR 1.68, CI 1.10-2.81; P = 0.048), and QTc ≥ 550 ms (HR 3.66, CI 2.34-5.72; P < 0.001) were associated with increased risk for recurrent appropriate shocks, while β-blockers were not protective (HR 1.03, CI 0.63-1.68, P = 0.917). LQT2 (HR 2.10, CI 1.22-3.61; P = 0.008) and multiple mutations (HR 2.87, CI 1.49-5.53; P = 0.002) were associated with higher risk for recurrent shocks as compared with LQT1. In this prospective ICD registry, we identified clinical and genetic variables that were associated appropriate shock risk. These data can be used for risk stratification in high-risk patients evaluated for primary prevention with ICD.

Implantable cardioverter defibrillators in the prevention of sudden cardiac death

The article highlights the role of implantable cardioverter defibrillators (ICDs) in the primary and secondary prevention of sudden cardiac death. It considers the results of multicenter studies comparing the efficacy of antiarrhythmic drugs and implantable devices in the primary and secondary prevention of sudden cardiac death, including that in patients with nonischemic cardiomyopathy and discusses quality of life in patients with ICDs.

Long-term outcomes of aCaucasian cohort presenting with acute coronary syndrome and/or out-of-hospital cardiac arrest caused by coronary spasm.

BackgroundCoronary artery spasm may be the underlying mechanism in up to 10% of cases of acute coronary syndrome (ACS) and sudden cardiac death. Asian individuals exhibit a 3-times greater incidence of spasm than Caucasians; this is likely due to different types of mechanisms. Consequently, solid data is limited about the long-term prognosis in Caucasian patients presenting with ACS and/or out-of-hospital cardiac arrest (OHCA) caused by coronary spasm.MethodsBetween 2002 and 2015, thirty Caucasian patients with coronary artery spasm presenting with ACS (N = 29) and/or OHCA (N = 11) were enrolled in this prospective registry. Follow-up, consisting of regular outpatient visits, was conducted with a mean follow-up period of 7.5 ± 3.3 years. Outcomes included presence of stable angina pectoris, recurrence of ACS, occurrence of implantable cardioverter defibrillator (ICD) shocks and death.ResultsThe majority of patients (60%) remained asymptomatic during the entire follow-up period. At the end of the follow-up period only 3 patients still experienced stable angina (10%). Only 2 patients (7%) had a recurrent cardiac event, in which the ICD provided appropriate shock therapy. Half of the patients treated with stenting (N = 6), required re-interventions.ConclusionCoronary spasm with ACS and/or OHCA in a Caucasian patient cohort has a relatively benign prognosis in the majority of patients in long-term follow-up, if treated appropriately with medical therapy. Both the role of ICD in OHCA secondary to coronary spasm, and the efficacy of stenting to treat vasospastic angina, warrant further study in large-sized prospective clinical trials.