Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

AIMS: Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. METHODS AND RESULTS: The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). CONCLUSION: Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Epinephrine before defibrillation in patients with shockable in-hospital cardiac arrest: propensity matched analysis.

OBJECTIVE: To determine the use of epinephrine (adrenaline) before defibrillation for treatment of in-hospital cardiac arrest due to a ventricular arrhythmia and examine its association with patient survival. DESIGN: Propensity matched analysis. SETTING: 2000-18 data from 497 hospitals participating in the American Heart Association's Get With The Guidelines-Resuscitation registry. PARTICIPANTS: Adults aged 18 and older with an index in-hospital cardiac arrest due to an initial shockable rhythm treated with defibrillation. INTERVENTIONS: Administration of epinephrine before first defibrillation. MAIN OUTCOME MEASURES: Survival to discharge; favorable neurological survival, defined as survival to discharge with none, mild, or moderate neurological disability measured using cerebral performance category scores; and survival after acute resuscitation (that is, return of spontaneous circulation for >20 minutes). A time dependent, propensity matched analysis was performed to adjust for confounding due to indication and evaluate the independent association of epinephrine before defibrillation with study outcomes. RESULTS: Among 34 820 patients with an initial shockable rhythm, 7054 (20.3%) were treated with epinephrine before defibrillation, contrary to current guidelines. In comparison with participants treated with defibrillation first, participants receiving epinephrine first were less likely to have a history of myocardial infarction or heart failure, but more likely to have renal failure, sepsis, respiratory insufficiency, and receive mechanical ventilation before in-hospital cardiac arrest (standardized differences >10% for all). Treatment with epinephrine before defibrillation was strongly associated with delayed defibrillation (median 4 minutes v 0 minutes). In propensity matched analysis (6569 matched pairs), epinephrine before defibrillation was associated with lower odds of survival to discharge (22.4% v 29.7%; adjusted odds ratio 0.69; 95% confidence interval 0.64 to 0.74; P<0.001), favorable neurological survival (15.8% v 21.6%; 0.68; 0.61 to 0.76; P<0.001) and survival after acute resuscitation (61.7% v 69.5%; 0.73; 0.67 to 0.79; P<0.001). The above findings were consistent in a range of sensitivity analyses, including matching according to defibrillation time. CONCLUSIONS: Contrary to current guidelines that prioritize immediate defibrillation for in-hospital cardiac arrest due to a shockable rhythm, one in five patients are treated with epinephrine before defibrillation. Use of epinephrine before defibrillation was associated with worse survival outcomes.

Cardioversion in patients with newly diagnosed non-valvular atrial fibrillation: observational study using prospectively collected registry data.

OBJECTIVE: To investigate the clinical outcomes of patients who underwent cardioversion compared with those who did not have cardioverson in a large dataset of patients with recent onset non-valvular atrial fibrillation. DESIGN: Observational study using prospectively collected registry data (Global Anticoagulant Registry in the FIELD-AF-GARFIELD-AF). SETTING: 1317 participating sites in 35 countries. PARTICIPANTS: 52 057 patients aged 18 years and older with newly diagnosed atrial fibrillation (up to six weeks' duration) and at least one investigator determined stroke risk factor. MAIN OUTCOME MEASURES: Comparisons were made between patients who received cardioversion and those who had no cardioversion at baseline, and between patients who received direct current cardioversion and those who had pharmacological cardioversion. Overlap propensity weighting with Cox proportional hazards models was used to evaluate the effect of cardioversion on clinical endpoints (all cause mortality, non-haemorrhagic stroke or systemic embolism, and major bleeding), adjusting for baseline risk and patient selection. RESULTS: 44 201 patients were included in the analysis comparing cardioversion and no cardioversion, and of these, 6595 (14.9%) underwent cardioversion at baseline. The propensity score weighted hazard ratio for all cause mortality in the cardioversion group was 0.74 (95% confidence interval 0.63 to 0.86) from baseline to one year follow-up and 0.77 (0.64 to 0.93) from one year to two year follow-up. Of the 6595 patients who had cardioversion at baseline, 299 had a follow-up cardioversion more than 48 days after enrolment. 7175 patients were assessed in the analysis comparing type of cardioversion: 2427 (33.8%) received pharmacological cardioversion and 4748 (66.2%) had direct current cardioversion. During one year follow-up, event rates (per 100 patient years) for all cause mortality in patients who received direct current and pharmacological cardioversion were 1.36 (1.13 to 1.64) and 1.70 (1.35 to 2.14), respectively. CONCLUSION: In this large dataset of patients with recent onset non-valvular atrial fibrillation, a small proportion were treated with cardioversion. Direct current cardioversion was performed twice as often as pharmacological cardioversion, and there appeared to be no major difference in outcome events for these two cardioversion modalities. For the overall cardioversion group, after adjustments for confounders, a significantly lower risk of mortality was found in patients who received early cardioversion compared with those who did not receive early cardioversion. STUDY REGISTRATION: ClinicalTrials.gov NCT01090362.

Comparative Effectiveness of Implantable Defibrillators for Asymptomatic Brugada Syndrome: A Decision-Analytic Model.

Background Optimal management of asymptomatic Brugada syndrome (BrS) with spontaneous type I electrocardiographic pattern is uncertain. Methods and Results We developed an individual-level simulation comprising 2 000 000 average-risk individuals with asymptomatic BrS and spontaneous type I electrocardiographic pattern. We compared (1) observation, (2) electrophysiologic study (EPS)-guided implantable cardioverter-defibrillator (ICD), and (3) upfront ICD, each using either subcutaneous or transvenous ICD, resulting in 6 strategies tested. The primary outcome was quality-adjusted life years (QALYs), with cardiac deaths (arrest or procedural-related) as a secondary outcome. We varied BrS diagnosis age and underlying arrest rate. We assessed cost-effectiveness at $100 000/QALY. Compared with observation, EPS-guided subcutaneous ICD resulted in 0.35 QALY gain/individual and 4130 cardiac deaths avoided/100 000 individuals, and EPS-guided transvenous ICD resulted in 0.26 QALY gain and 3390 cardiac deaths avoided. Compared with observation, upfront ICD reduced cardiac deaths by a greater margin (subcutaneous ICD, 8950; transvenous ICD, 6050), but only subcutaneous ICD improved QALYs (subcutaneous ICD, 0.25 QALY gain; transvenous ICD, 0.01 QALY loss), and complications were higher. ICD-based strategies were more effective at younger ages and higher arrest rates (eg, using subcutaneous devices, upfront ICD was the most effective strategy at ages 20-39.4 years and arrest rates >1.37%/year; EPS-guided ICD was the most effective strategy at ages 39.5-51.3 years and arrest rates 0.47%-1.37%/year, and observation was the most effective strategy at ages >51.3 years and arrest rates <0.47%/year). EPS-guided subcutaneous ICD was cost-effective ($80 508/QALY). Conclusions Device-based approaches (with or without EPS risk stratification) can be more effective than observation among selected patients with asymptomatic BrS. BrS management should be tailored to patient characteristics.

Temporal trends in outcome and patient characteristics in dilated cardiomyopathy, data from the Swedish Heart Failure Registry 2003-2015.

BACKGROUND: Temporal trends in clinical composition and outcome in dilated cardiomyopathy (DCM) are largely unknown, despite considerable advances in heart failure management. We set out to study clinical characteristics and prognosis over time in DCM in Sweden during 2003-2015. METHODS: DCM patients (n = 7873) from the Swedish Heart Failure Registry were divided into three calendar periods of inclusion, 2003-2007 (Period 1, n = 2029), 2008-2011 (Period 2, n = 3363), 2012-2015 (Period 3, n = 2481). The primary outcome was the composite of all-cause death, transplantation and hospitalization during 1 year after inclusion into the registry. RESULTS: Over the three calendar periods patients were older (p = 0.022), the proportion of females increased (mean 22.5%, 26.4%, 27.6%, p = 0.0001), left ventricular ejection fraction was higher (p = 0.0014), and symptoms by New York Heart Association less severe (p < 0.0001). Device (implantable cardioverter defibrillator and/or cardiac resynchronization) therapy increased by 30% over time (mean 11.6%, 12.3%, 15.1%, p < 0.0001). The event rates for mortality, and hospitalization were consistently decreasing over calendar periods (p < 0.0001 for all), whereas transplantation rate was stable. More advanced physical symptoms correlated with an increased risk of a composite outcome over time (p = 0.0043). CONCLUSIONS: From 2003 until 2015, we observed declining mortality and hospitalizations in DCM, paralleled by a continuous change in both demographic profile and therapy in the DCM population in Sweden, towards a less affected phenotype.

Atrial fibrillation increases the risk of recurrent ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients.

BACKGROUND: Data regarding recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator (ICD) recipients according to atrial fibrillation is limited. OBJECTIVE: To assess the prognostic impact of atrial fibrillation on recurrences of ventricular tachyarrhythmias in implantable cardioverter defibrillator recipients. METHODS: A large retrospective registry was used, including all ICD recipients with episodes of ventricular tachycardia or fibrillation from 2002 to 2016. Patients with atrial fibrillation were compared to those without atrial fibrillation. The primary endpoint was first recurrence of ventricular tachyarrhythmias at 5 years. Secondary endpoints comprised recurrences of ICD-related therapies, first cardiac rehospitalization and all-cause mortality at 5 years. Cox regression, Kaplan-Meier and propensity score-matching analyses were applied. RESULTS: A total of 592 consecutive ICD recipients were included (33% with atrial fibrillation). Atrial fibrillation was associated with reduced freedom from recurrent ventricular tachyarrhythmias (42% vs. 50%, log-rank P=0.004; hazard ratio 1.445, 95% confidence interval 1.124-1.858), mainly attributable to recurrent ventricular fibrillation in secondary-preventive ICD recipients. Accordingly, atrial fibrillation was associated with reduced freedom from first appropriate ICD therapies (31% vs. 42%, log-rank P=0.001; hazard ratio 1.598, 95% confidence interval 1.206-2.118). Notably, the primary endpoint of freedom from first episode of recurrent ventricular tachyarrhythmias was still reduced in those with atrial fibrillation compared to those without atrial fibrillation after propensity score matching. Regarding secondary endpoints, patients with atrial fibrillation still showed a trend towards reduced freedom from appropriate ICD therapies. CONCLUSIONS: Atrial fibrillation was associated with increased rates of recurrent ventricular tachyarrhythmias and appropriate device therapies in ICD recipients with ventricular tachyarrhythmias.

Mid-term results after isolated tricuspid valve surgery in the presence of right ventricular leads.

BACKGROUND: Patients with tricuspid valve (TV) disease and indication for TV surgery frequently have permanent pacemaker (PM) or defibrillator (AICD) leads, placed in the right ventricle (RV). The aim of this study was to analyze postoperative results and mid-term outcomes after isolated TV surgery (with no further concomitant cardiac procedures) in the presence of permanent RV leads. METHODS: From January 2005 to January 2019 a total of 80 patients (mean age: 67.7±10.3 yrs; 56.3% male) with isolated TV disease and presence of at least one permanent RV lead in place were referred to our institution for isolated TV repair/replacement; patients with concomitant procedures were excluded for this analysis. All data were retrospectively analyzed. The follow-up was 98% complete. RESULTS: Mean follow-up time was 4.3±3.9 years. Mean preoperative clinical NYHA status was 3.0±0.8, left ventricular ejection fraction 50.7±12.9%, mean pulmonary artery pressure 23.8±9.3mmHg, creatinine 125.7±57.5µmol/L, mean MELD-XI Score (Model of End-stage-Liver Disease excluding INR) was 14.6±5.0 µmol/L. Thirty-day mortality was 6.3% with a 5-years survival of 58.2±6.0%. Cox regression analysis revealed the MELD-XI-Score as the only highly significant predictor for postoperative mortality (P=0.002). CONCLUSIONS: Hepatorenal dysfunction - possibly indicating long lasting TV failure - could be a factor for limited postoperative survival in our patient cohort. This finding could underline our hypothesis, that early TV surgery may achieve better postoperative survival, even in patients with TV disease caused by RV leads. Therefore, further investigations are needed.

Management of Arrhythmias After Heart Transplant: Current State and Considerations for Future Research.

Orthotropic heart transplantation remains the most effective therapy for patients with end-stage heart failure, with a median survival of ≈13 years. Yet, a number of complications are observed after orthotropic heart transplantation, including atrial and ventricular arrhythmias. Several factors contribute to arrhythmias, such as autonomic denervation, effect of the surgical technique, acute and chronic rejection, and transplant vasculopathy among others. To minimize risk of future arrhythmias, the bicaval technique and minimizing ischemic time are current surgical standards. Sinus node dysfunction is the most common indication for early (within 30 days) pacemaker implantation, whereas atrioventricular block incidence increases as time from transplant increases. Atrial fibrillation can occur in the first few weeks following transplantation but is uncommon in the long term unless secondary to a precipitant such as acute rejection. The most common atrial arrhythmias are atrial flutters, which are mainly typical, but atypical circuits can be observed such as those that involve the remnant donor atrium in regions immediately adjacent to the atrioatrial anastomosis suture line. Choosing the appropriate pharmacological therapy requires careful consideration due to the potential interaction with immunosuppressive agents. Despite historical concerns, adenosine is effective and safe at reduced doses if administered under cardiac monitoring. Catheter ablation has emerged as an effective treatment strategy for symptomatic supraventricular tachycardias, including ablation of atypical flutter circuits. Cardiac allograft vasculopathy is an important risk factor for sudden cardiac death, yet the role of prophylactic implantable cardioverter-defibrillator implant for sudden death prevention is unclear. Current indications for implantable cardioverter-defibrillator implantation are as in the nontransplant population. A number of questions for future research are posed.

Management and outcomes of hypertrophic cardiomyopathy in young adults.

BACKGROUND: Management of young adults with hypertrophic cardiomyopathy (HCM) is challenging. AIMS: To evaluate the profile of young adults (16-25 years) with HCM included in the French prospective HCM registry. METHODS: Patients were compared according to occurrence of major adverse cardiac events (MACE), comprising sudden cardiac death (SCD) events (implantable cardioverter defibrillator [ICD] discharge, SCD, sustained ventricular tachycardia), atrial fibrillation/embolic stroke, heart failure hospitalisation and unexplained syncope, at a mean follow-up of 4.4±2.2 years. RESULTS: At baseline, among 61 patients (20.5±3.0 years; 16 women, 26.2%), 13 (21.3%) had a prophylactic ICD, 24.6% a family history of SCD, 29.5% obstruction, 86.0% magnetic resonance imaging myocardial fibrosis, 11.8% abnormal exercise blood pressure and 52.8% a European Society of Cardiology (ESC) 5-year SCD score<4% (24.5%≥6%). At follow-up, 15 patients (24.6%; seven women; all with fibrosis) presented 17 MACE, comprising: SCD events (n=7, 41.2%; including three patients with an ICD, five with at least one SCD major classical risk factor and an ESC score≥5% and two with no risk factors and an ESC score<4%); atrial fibrillation/stroke (n=6, 35.3%); heart failure (n=1, 5.9%); syncope (n=3, 17.6%). An ICD was implanted in 11 patients (four for secondary prevention), but in only 61.5% of patients with a score≥6%. Only obstruction significantly increased MACE risk (odds ratio 3.96; P=0.035), with a non-significant trend towards a lower risk in men (OR 0.29; P=0.065). CONCLUSIONS: In young adults with HCM, MACE are common in the short term, especially in obstructive HCM and women, mostly arrhythmic in origin. Prophylactic ICD implantation is frequent and does not strictly follow the guidelines, while the use of European/USA guidelines is helpful but imperfect in identifying SCD risk.

Ongoing Risk of Ventricular Arrhythmias and All-Cause Mortality at Implantable Cardioverter Defibrillator Generator Change: A Systematic Review and Meta-Analysis.

[Figure: see text].

Wearable cardioverter-defibrillators: A review of evidence and indications.

The wearable cardioverter-defibrillator (WCD) was first approved for clinical use in 2002, and is routinely used in select populations at high risk for sudden cardiac death. WCDs are frequently considered as a bridge to definitive therapy or in circumstances where insertion of conventional implantable cardioverter-defibrillators (ICD) is temporarily contraindicated. In this review, we summarize the literature on WCDs. From prospective trials to the first randomized controlled trial with WCD, there is a growing body of evidence that suggests that the WCD is safe and effective. In the first randomized controlled trial of the WCD (VEST Trial), there was no reduction in arrhythmia death but there was a reduction in all-cause mortality. We discuss the mortality impact, rate of inappropriate shocks, compliance, and potential quality of life implications with the WCD. Finally, we present the evidence for WCD use in select populations (e.g., post-myocardial infarction, device extraction), and the current guideline recommendations for WCD use.

Predictors of Subcutaneous Implantable Cardioverter-Defibrillator Shocks and Prognostic Impact in Patients With Structural Heart Disease.

BACKGROUND: In this study we aimed to assess long-term outcomes in subcutaneous implantable cardioverter-defibrillator (S-ICD) recipients with structural heart disease by focussing especially on shock incidence, predictors, and associated prognoses. METHODS: In this multicenter registry‒based study, we retrospectively included all patients who underwent S-ICD implantation at 3 tertiary centers. The prognostic impact of S-ICD shock was assessed with a composite outcome that included all-cause death and hospitalisation for heart failure. RESULTS: A total of 351 patients with underlying cardiomyopathy were included in the investigation. Using multivariable Fine and Gray regression models, secondary prevention, left ventricular ejection fraction (LVEF), conditional shock threshold, and QRS duration appeared to be independent predictors of appropriate S-ICD shock occurrence. In the multivariate Cox regression model adjusted for age, baseline LVEF, underlying cardiomyopathy subtype, New York Heart Association class, and appropriate shocks were significantly associated with increased composite prognostic outcome risk (hazard ratio [HR], 2.61; 95% confidence interval [CI], 1.21-5.65; P = 0.014), whereas inappropriate shocks were not (HR, 1.35; 95% CI, 0.75-4.48; P = 0.18). The analysis of each component of the composite prognostic outcome highlighted that the occurrence of appropriate shocks was associated with an increased risk of hospitalisation for heart failure (HR, 3.10; 95% CI, 1.26-7.58; P = 0.013) and a trend for mortality (HR, 2.19; 95% CI, 0.78-6.16; P = 0.14). CONCLUSIONS: Appropriate S-ICD shocks were associated with a 3-fold increase in acute heart failure admission, whereas inappropriate shocks were not. Conditional shock threshold programming is an independent predictor of S-ICD shock, and its prognostic impact should be investigated further in patients with structural heart disease.

Long-Term Outcome of the Randomized DAPA Trial.

BACKGROUND: The randomized DAPA trial (Defibrillator After Primary Angioplasty) aimed to evaluate the survival benefit of prophylactic implantable cardioverter defibrillator (ICD) implantation in early selected high-risk patients after primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction. METHODS: A randomized, multicenter, controlled trial compared ICD versus conventional medical therapy in high-risk patients with primary percutaneous coronary intervention, based on one of the following factors: left ventricular ejection fraction <30% within 4 days after ST-segment-elevation myocardial infarction, primary ventricular fibrillation, Killip class ≥2 or TIMI (Thrombolysis in Myocardial Infarction) flow <3 after percutaneous coronary intervention. ICD was implanted 30 to 60 days after MI. Primary end point was all-cause mortality at 3 years follow-up. The trial prematurely ended after inclusion of 266 patients (38% of the calculated sample size). Additional survival assessment was performed in February 2019 for the primary end point. RESULTS: A total of 266 patients, 78.2% males, with a mean age of 60.8±11.3 years, were enrolled. One hundred thirty-one patients were randomized to the ICD arm and 135 patients to the control arm. All-cause mortality was significant lower in the ICD group (5% versus 13%, hazard ratio, 0.37 [95% CI, 0.15-0.95]) after 3 years follow-up. Appropriate ICD therapy occurred in 9 patients at 3 years follow-up (5 within the first 8 months after implantation). After a median long-term follow-up of 9 years (interquartile range, 3-11), total mortality (18% versus 38%; hazard ratio, 0.58 [95% CI, 0.37-0.91]), and cardiac mortality (hazard ratio, 0.52 [95% CI, 0.28-0.99]) was significant lower in the ICD group. Noncardiac death was not significantly different between groups. Left ventricular ejection fraction increased ≥10% in 46.5% of the patients during follow-up, and the extent of improvement was similar in both study groups. CONCLUSIONS: In this prematurely terminated and thus underpowered randomized trial, early prophylactic ICD implantation demonstrated lower total and cardiac mortality in patients with high-risk ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention. Registration: URL: https://www.trialregister.nl; Unique identifier: Trial NL74 (NTR105).

Factors associated with implantable cardioverter defibrillators appropriate therapy in cardiac sarcoidosis: a meta-analysis.

BACKGROUND: Patients with cardiac sarcoidosis (CS) are at increased risk of atrioventricular blocks, ventricular arrhythmias, and sudden cardiac death. Objectives We aimed to investigate the characteristics associated with appropriate therapy in implantable cardiac defibrillator (ICD) -implanted CS patients. METHODS: We performed a PubMed and Web of Science search for studies reporting patients with CS who underwent an ICD implantation. The primary criterion was an appropriate therapy. RESULTS: We screened 705 studies, of which 5 were included in the final analysis. We conducted a meta-analysis including 464 patients (mean age 55 years, 282 males (60%)). The mean follow-up was 3.5 years. Among the 464 patients, 180 received an appropriate therapy (39%). Patients who received an appropriate therapy were younger (-3.33, 95% confidence interval (CI) -6.42 to -0.23, p=0.004), were more likely to be male (OR 2.06, 95% CI 1.37-3.09, p=0.0005), had a lower left ventricular ejection fraction (LVEF) (-10.5, 95% CI -18.23 to -2.78, p=0.008), had a higher rate of complete heart block (OR 2.19, 95% CI 1.20 to 3.99, p=0.01), and more frequently had ventricular pacing (OR 6.44 95% CI 2.57 to 16.16, p<0.0001). CONCLUSIONS: Appropriate ICD therapy during CS is associated with young age, male sex, low LVEF, history of complete heart block, and ventricular pacing. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (1): 17-23).

The effect of revascularization on mortality and risk of ventricular arrhythmia in patients with ischemic cardiomyopathy.

BACKGROUND: There is clear evidence that patients with prior myocardial infarction and a reduced ejection fraction benefit from implantation of a cardioverter-defibrillator (ICD). It is unclear whether this benefit is altered by whether or not revascularization is performed prior to ICD implantation. METHODS: This was a retrospective cohort study following patients who underwent ICD implantation from 2002 to 2014. Patients with ischemic cardiomyopathy and either primary or secondary prevention ICDs were selected for inclusion. Using the electronic medical record, cardiac catheterization data, revascularization status (percutaneous coronary intervention or coronary bypass surgery) were recorded. The outcomes were mortality and ventricular arrhythmia. RESULTS: There were 606 patients included in the analysis. The mean age was 66.3 ± 10.1 years, 11.9% were women, and the mean LVEF was 30.5 ± 12.0, 58.9% had a primary indication for ICD, 82.0% of the cohort had undergone coronary catheterization prior to ICD implantation. In the overall cohort, there were fewer mortality and ventricular arrhythmia events in patients who had undergone prior revascularization. In patients who had an ICD for secondary prevention, revascularization was associated with a decrease in mortality (HR 0.46, 95% CI (0.24, 0.85) p = 0.015), and a trend towards fewer ventricular arrhythmia (HR 0.62, 95% CI (0.38, 1.00) p = 0.051). There was no association between death or ventricular arrhythmia with revascularization in patients with primary prevention ICDs. CONCLUSION: Revascularization may be beneficial in preventing recurrent ventricular arrhythmia, and should be considered as adjunctive therapy to ICD implantation to improve cardiovascular outcomes.

Long-Term Outcome in High-Risk Patients With Hypertrophic Cardiomyopathy After Primary Prevention Defibrillator Implants.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) is effective for preventing sudden death in patients with hypertrophic cardiomyopathy. However, data on performance and complications of implanted ICDs over particularly long time periods to inform clinical practice is presently incomplete. METHODS: The study cohort comprises 217 consecutive hypertrophic cardiomyopathy patients with primary prevention ICDs implanted before 2008 and followed for ≥10 years (mean 12±4; range to 31). RESULTS: Patients were 38±17 years at implant and 45 (21%) experienced appropriate interventions terminating ventricular tachycardia/ventricular fibrillation. The majority of ICD discharges occurred ≥5 years after implant (29 patients; 64%), including ≥10 years in 16 patients (36%). Initial device therapy increased in frequency from 2.3% of patients at <1 year to 8.5% of patients at ≥10-years after implant (P=0.005). Inappropriate ICD shocks in 39 patients occurred most commonly <5 years after implant (54%) and decreased in frequency with increasing time from implant (from 9.7% of patients at <5 years to 3.8% at ≥10 years, P=0.02). Other major device complications including infection and lead fractures and dislodgement occurred in 27 patients (12%) but did not increase in frequency over follow-up after implant (P=0.47). There were no arrhythmic sudden death events among the 217 patients with ICD. CONCLUSIONS: In hypertrophic cardiomyopathy, after a primary prevention implant, ICD therapy often followed prolonged periods of device dormancy and increased progressively in frequency over time, including one-third of patients with initial therapy after 5 to 9 years, and an additional one-third of patients at ≥10 years. Frequency of inappropriate shocks decreased over follow-up, likely reflecting standard changes in device programming, while occurrence of device complications, such as lead fractures/infection, did not increase during follow-up.

Outcomes of Cardiac Resynchronization Therapy in Patients with Hypothyroidism and Heart Failure.

BACKGROUND: Hypothyroidism is known to be associated with adverse clinical outcomes in heart failure. The association between hypothyroidism and cardiac resynchronization therapy outcomes in patients with severe heart failure is not clear. METHODS: The study included 1316 patients who received cardiac resynchronization therapy between 2002 and 2015. Baseline demographics and cardiac resynchronization therapy outcomes, including left ventricular ejection fraction, New York Heart Association class, appropriate implantable cardioverter-defibrillator therapy, and all-cause mortality, were collected from the electronic health record. RESULTS: Of the study cohort, 350 patients (26.6%) were classified as the hypothyroidism group. The median duration of follow-up was 3.6 years (interquartile range, 1.7-6.2 years). Hypothyroidism was not associated with a higher risk of all-cause mortality in patients receiving CRT for heart failure. The risk of appropriate implantable cardioverter-defibrillator therapy significantly increased in association with increased baseline thyroid-stimulating hormone level in the entire cohort (hazard ratio, 1.23 per 5mIU/L increase; 95% CI, 1.01-1.5; P = 0.04) as well as in the hypothyroid group (hazard ratio, 1.44 per 5mIU/L increase; 95% CI, 1.13-1.84; P = 0.004). CONCLUSIONS: CRT improves cardiac function in hypothyroid patients. The ventricular arrhythmic events requiring ICD therapies are associated with baseline TSH level, which might be considered as an important biomarker to stratify the risk of sudden death for patients with heart failure and hypothyroidism.

The automated external defibrillator, an underused simple life-saving device: a review of the literature. A joint document from the Italian Resuscitation Council (IRC) and Associazione Italiana di Aritmologia e Cardiostimolazione (AIAC).

: The role of early defibrillation has been well established as a pivotal ring of the chain of survival since the nineties. In the following years, the scientific evidences about the beneficial role of early defibrillation have grown, and most of all, it has been demonstrated that the main determinant of survival is the time of defibrillation more than the type of rescuer. Early lay defibrillation was shown to be more effective than delayed defibrillation by healthcare providers. Moreover, because of the ease of use of automated external defibrillators (AEDs), it has been shown that also untrained lay rescuers can safely use an AED leading the guidelines to encourage early defibrillation by untrained lay bystanders. Although strong evidence has demonstrated that an increase in AED use leads to an increase in out-of-hospital cardiac arrest (OHCA) survival, the rate of defibrillation by laypeople is quite variable worldwide and very low in some realities. Our review of the literature about lay defibrillation highlights that the AED is a life-saving device as simple and well tolerated as underused.