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The Multicenter Automatic Defibrillator Implantation Trial - Reduce Inappropriate Therapy showed a significant reduction in the risk of inappropriate therapy in patients with a programmed high-rate cutoff ≥200 beats per minute or delayed therapy for events ≥170 beats per minute compared with conventional programming. We aimed to characterize outcomes by left ventricular ejection fraction (LVEF) ranges for patients with high-rate, delayed, or conventional implantable cardioverter-defibrillator programming. We assessed the effect of LVEF (LVEFlt;15%, LVEF 15% to 25%, LVEFgt;25%) on the risk of inappropriate conventional implantable cardioverter-defibrillator therapy and death in Multicenter Automatic Defibrillator Implantation Trial - Reduce Inappropriate Therapy. Inappropriate therapies and death were independently evaluated by the adjudication committee. Statistical methods involved Kaplan-Meier time-to-event graphs and Cox proportional hazards regression analyses. The study involved 140 patients (9%) with LVEF 15%, 585 with LVEF 15% to 25% (39%), and 774 with LVEFgt;25% (52%). High-rate or delayed programming significantly reduced the risk of inappropriate therapy compared with conventional programming in patients with all LVEFs (plt;0.001 for all LVEF). Patients with LVEFlt;15% had an exceptional 97% lower risk of inappropriate therapy, with high-rate programming than conventional programming (hazard ratio 0.028, p = 0.001), without an increase in mortality. High-rate and delayed programming is superior to conventional programming in all LVEF ranges, without adverse effects.

Background: Women with congenital long QT syndrome (LQTS) experience increased cardiac event risk after the onset of adolescence, perhaps stemming from the known modulating effects of sex hormones on the cardiac potassium channels. Objective: We hypothesized that the effect of sex hormones on cardiac ion channel function may modify electrocardiographic (ECG) parameters associated with the propensity for ventricular tachyarrhythmias during the menstrual cycle in women with LQTS. Methods: We prospectively enrolled 65 women with congenital LQTS (type 1 LQTS [LQT1], n = 24 [36.9%]; type 2 LQTS [LQT2], n = 20 [30.8%]) and unaffected female relatives (n = 21 [32.3%]). Patients underwent three 7-day ECG recordings during their menstrual cycles. Simultaneous saliva testing of sex hormone levels was conducted on the first day of each 7-day ECG recording cycle. Results: The mean age was 35 ± 8 years, without a significant difference among the groups. In women with LQT2, linear mixed effects models showed significant inverse correlations of the corrected QT interval with progesterone levels (P < .001) and with the progesterone to estradiol ratio (P < .001). Inverse relationships of the R-R interval with estradiol levels (P = .003) and of the T-wave duration with testosterone levels (P = .014) were also observed in women with LQT2. In contrast, no significant associations were observed between ECG parameters and sex hormone levels in women with LQT1 or unaffected relatives. Conclusion: This is the first study to prospectively assess correlations between repolarization dynamics and sex hormone levels during the menstrual cycle in women with congenital LQTS. Our findings show genotype-specific unique corrected QT dynamics during the menstrual cycle that may affect the propensity for ventricular tachyarrhythmia in women with LQTS, particularly women with LQT2.

Current guidelines do not account for possible sex differences in the risk of ventricular tachyarrhythmia (VTA). We sought to identify specific factors associated with increased risk for VTA in women implanted with a primary prevention implantable cardioverter-defibrillator (ICD). Our study cohort consisted of 4,506 patients with an ICD or cardiac resynchronization therapy-defibrillator who were enrolled in the 4 landmark MADIT studies - MADIT-II, MADIT-RISK, MADIT-CRT and MADIT-RIT (1,075 women [24%]). Fine and Gray regression models were used to identify female-specific risk factors for the primary end point of VTA, defined as ICD-recorded, treated, or monitored, sustained ventricular tachycardia ≥170 beats per minute or ventricular fibrillation. At 3.5 years of follow-up, the cumulative incidence of VTA was significantly lower in women than men (17% vs 26%, respectively; p0.001 for the entire follow-up). Use of amiodarone at enrollment, Black race, and history of previous myocardial infarction without previous revascularization was found to be independent risk factors of VTA in women. Of these factors, only Black race was associated with a statistically significant risk increase in men. At 3.5 years, the cumulative incidence of VTA in women with one or more of these risk factors was 27% compared with 14% in women with none of the risk factors (hazard ratio [confidence interval] = 2.08 [1.49 to 2.91]). In conclusion, our study, comprising 4 landmark ICD clinical trials, shows that sex and race have the potential to be used for improved risk stratification of patients who are candidates for primary prevention ICD.

Introduction: Wearable Cardioverter Defibrillator (WCD) is utilized in patients with assumed but not yet confirmed risk for sudden cardiac death (SCD). Many of these patients also present with atrial fibrillation (AF). However, the rate of WCD-detected ventricular or atrial arrhythmia events in this specific high-risk cohort is not well understood. Methods: In WEARIT-II, the cumulative probability of any sustained or non-sustained VT/VF (WCD-treated and non-treated), and atrial/supraventricular arrhythmias during WCD use was assessed using the Kaplan-Meier method by prior AF, with comparisons by the log-rank test. The incidence of ventricular and atrial arrhythmia events were expressed as events per 100 patient-years, and were analyzed by prior AF using negative binomial regression. Results: WEARIT-II enrolled 2000 patients, 557 (28%) of whom had AF prior to enrollment. Cumulative probability of any sustained or non-sustained WCD-detected VT/VF during WCD use was significantly higher among patients with a history of AF than without AF (6% vs. 3%, p=0.001). Similarly, the recurrent rate of any sustained or non-sustained VT/VF was significantly higher in patients with prior AF vs. no prior AF (131.5 events per 100 patient-years vs. 22.7 events per 100 patient-years, p=0.001). Patients with prior AF also had a significantly higher burden of any WCD-detected atrial arrhythmias/SVT/inappropriate therapy (183.2 events per 100 patient-years vs. 74.8 events per 100 patient-years, pConclusion: Our results demonstrate that patients with a history of AF wearing the WCD for risk assessment have a higher incidence of ventricular arrhythmias that may facilitate the decision making for ICD implantation.

BackgroundBlack Americans have a higher risk of non-ischemic cardiomyopathy (NICM) than White Americans. We aimed to evaluate racial disparities in the risk of tachyarrhythmias among patients with an implantable cardioverter defibrillator (ICD).MethodsThe study population comprised 3,895 ICD recipients enrolled in the U.S. in primary prevention ICD trials. Outcome measures included first and recurrent ventricular tachy-arrhythmia (VTA) and atrial tachyarrhythmia (ATA), derived from adjudicated device data, and death. Outcomes were compared between self-reported Black vs. White patients with a cardiomyopathy (ischemic [ICM] and NICM).ResultsBlack patients were more likely to be female (35% vs 22%) and younger (57±12 vs 62±12) with a higher frequency of comorbidities. Blacks patients with NICM compared with Whites patients had a higher rate of first VTA, fast VTA, ATA, appropriate-, and inappropriate-ICD-therapy (VTA≥170bpm: 32% vs. 20%; VTA≥200bpm: 22% vs. 14%; ATA: 25% vs. 12%; appropriate 30% vs 20%; and inappropriate: 25% vs. 11%; pburdenof VTA, ATA, ICD therapies, and a higher risk of death (HR=1.86; p=0.014). In contrast, in ICM, the risk of all types of tachyarrhythmia, ICD therapy, or death was similar between Black and White patients.ConclusionsAmong NICM patients with an ICD for primary prevention, Black compared with White patients had a high risk and burden of VTA, ATA, and ICD therapies.Clinical PerspectiveWhat Is New?Black patients have a higher risk of developing non-ischemic cardiomyopathy (NICM) but are under-represented in clinical trials of implantable cardioverter defibrillators (ICD). Therefore, data on disparities in the presentation and outcomes in this population are limited.This analysis represents the largest group of self-identified Black patients implanted in the U.S. with an ICD for primary prevention with adjudication of all arrhythmic events.What Are the Clinical Implications?In patients with a NICM, self-identified Black compared to White patients experienced an increased incidence and burden of ventricular tachyarrhythmia, atrial tachyarrhythmia, and ICD therapies. These differenced were not observed in Black vs White patients with ischemic cardiomyopathy (ICM).Although Black patients with NICM were implanted at a significantly younger age (57±12 vs 62±12 years), they experienced a 2-fold higher rate of all-cause mortality during a mean follow up of 3 years compared with White patients.These findings highlight the need for early intervention with an ICD, careful monitoring, and intensification of heart failure and antiarrhythmic therapies among Black patients with NICM.

Background Use of oral contraceptives (OCs) may modulate the clinical course of women with congenital long QT syndrome (LQTS). The safety of OC use by sex hormone content has not been assessed in women with LQTS. Objective We aimed to evaluate the association of OCs with the risk of cardiac events (CEs) in women with LQTS. Methods Beginning in 2010, information on menarche onset, OC use, pregnancy, and menopause were obtained from women enrolled in the Rochester LQTS Registry. Type of OC was categorized as progestin-only, estrogen-only, or combined (estrogen/progestin). Andersen-Gill multivariate modeling was used to evaluate the association of time-dependent OC use with the burden of CE (total number of syncope, aborted cardiac arrest, and LQTS-related sudden cardiac death) from menarche onset through 40 years. Findings were adjusted for genotype, corrected QT duration, and time-dependent β-blocker therapy. Results A total of 1659 women with LQTS followed through March 2021, of whom 370 (22%) were treated with an OC. During a cumulative follow-up of 35,797 years, there were a total of 2027 CE. Multivariate analysis showed that progestin-only OC was associated with a pronounced 2.8-fold (P = .01) increased risk of CEs in women who did not receive β-blocker therapy, while β-blockers were highly protective during progestin-only OC treatment (hazard ratio 0.22; P = .01; P = .006 for β-blocker-by-OC interaction). The risk associated with OC use without concomitant β-blocker treatment was pronounced in women with LQTS type 2. Conclusion Our findings suggest that progestin-only OC should not be administered in women with LQTS without concomitant β-blocker therapy. OCs should be used with caution in women with LQTS type 2.

Multidisciplinary Pulmonary Embolism Response Teams (PERTs) may improve the care of patients with a high risk of pulmonary embolism (PE). The impact of a PERT on long-term mortality has never been evaluated. An observational analysis was conducted of 137 patients before PERT implementation (between 2014 and 2015) and 231 patients after PERT implementation (between 2016 and 2019), presenting to the emergency department of an academic medical center with submassive and massive PE. The primary outcome was 6-month mortality, evaluated by univariate and multivariate analyses. PERT was associated with a sustained reduction in mortality through 6 months (6-month mortality rates of 14% post-PERT vs 24% pre-PERT, unadjusted hazard ratio of 0.57, Relative Risk Reduction of 43%, p = 0.025). There was a reduced length of stay following PERT implementation (9.1 vs 6.5 days, p = 0.007). Time from triage to a diagnosis of PE was independently predictive of mortality, and the risk of mortality was reduced by 5% for each hour earlier that the diagnosis was made. In conclusion, this study is the first to demonstrate an association between PERT implementation and a sustained reduction in 6-month mortality for patients with high-risk PE.

This study aimed to evaluate the risk of sustained life-threatening ventricular tachyarrhythmias (VTAs) after hospitalization for heart failure (HHF).HHF is common among patients with an implantable cardioverter-defibrillator (ICD).We analyzed all 5,511 ICD patients enrolled in the landmark MADIT (Multicenter Automatic Defibrillator Implantation Trial) and RAID (Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillator) trials. Multivariate Cox regression was used to evaluate the association of in-trial HHF occurrence with the risk of subsequent VTA and the composite end point of VTA or cardiac death.Mean age was 64 ± 11 years, 23% were women, 62% were ischemic, and 40% had cardiac resynchronization therapy with defibrillators. The 3-year cumulative rate of VTA subsequent to HHF was significantly higher than the corresponding rate without HHF (44% vs. 24%, respectively; p 0.001). After multivariable adjustment, time-dependent HHF was shown to be associated with a 79% increased risk for VTA and a 2.9-fold increased risk for VTA/cardiac death (p 0.001 for both). In-trial development of atrial tachyarrhythmia (ATA) was also identified as an independent risk factor for the VTA and VTA/cardiac death end points (hazard ratio [HR]: 1.59 and 1.43, respectively; p ≤ 0.001 for both) but did not affect the association of HHF with VTA. Subgroup analysis demonstrated that the association of HHF with the risk of subsequent VTA was maintained among risk subsets categorized by age, sex, history of ATA, and implantation indication, but was significantly more pronounced among patients with nonischemic versus ischemic cardiomyopathy (HR: 2.54 and 1.43, respectively; p for interaction = 0.017).HHF is a powerful risk factor for subsequent VTA in patients implanted with an ICD. These data may be used for improved risk stratification in this population.

The objective of this single-center, pilot, prospective, and historical control study is to evaluate safety and feasibility outcomes associated with left atrial appendage exclusion (LAAE) concomitant with left ventricular assist device (LVAD) implantation via less invasive surgery (LIS) as a stroke prevention strategy.A predefined number of 30 eligible subjects scheduled for LIS LVAD with LAAE were enrolled in the prospective arm between January 2020 and February 2021. Eligible retrospective LIS LVAD patients without LAAE were propensity-matched in a 1:1 ratio with the prospective arm subjects. The primary study objectives were to evaluate the safety, feasibility, and efficacy of the LAAE concomitant with LIS LVAD.Preoperative characteristics of patients in the Non-LAAE and LAAE groups were similar. LAAE was successfully excluded in all prospective patients (100%). Primary safety endpoints of chest tube output within the first 24 postoperative hours, Reoperation for bleeding within 48 h, and index hospitalization mortality demonstrated comparable safety of LAAE versus Non-LAAE with LIS LVAD. Cox proportional hazard regression demonstrated that LAAE with LIS LVAD was associated with 37% and 49% reduction in the risk of stroke and disabling stroke, respectively (p .05).Results from our pilot study demonstrated the safety and feasibility of LAAE concomitant with LIS LVAD as a stroke prevention strategy. This is the first prospective study describing LAAE performed concomitantly to less invasive LVAD implantation. The efficacy of LAAE in long-term stroke prevention needs to be confirmed in future prospective randomized clinical trials.

Patients with heart failure (HF) represent a large population of patients who are at high risk for complications related to undiagnosed atrial fibrillation (AF). However, currently there are limited modalities available for early AF detection in this high-risk population. An implantable cardiac monitor (ICM) is inserted subcutaneously and can provide long-term arrhythmia information via remote monitoring.Confirm-AF is a prospective randomized, nonblinded, two arm, multicenter clinical trial to be performed in the United States, enrolling 477 patients with a history of HF hospitalization and left ventricular ejection fraction35% from 30 medical sites. Patients will be randomized in a 2:1 fashion to undergo ICM implant with remote monitoring and symptom-triggered mobile app transmissions versus (vs.) Non-ICM management and follow-up. The primary objective of this trial is to compare the time to first detection of AF lasting 5 min using an Abbott ICM compared to non-ICM monitoring in symptomatic HF patients. This article describes the design and analytic plan for the Confirm-AF trial.The Confirm-AF trial seeks to accurately define the burden of AF in high-risk HF patients with LVEF 35% using an Abbott ICM. A finding showing significantly higher incidence of AF along with improved clinical outcomes with ICM monitoring is expected to have substantial clinical implications and may change the method of monitoring high-risk HF patients.

INTRODUCTION: Pulmonary embolism response teams (PERTs) were developed to assist with diagnosis, risk stratification, and management of intermediate and high-risk pulmonary embolism (PE) and have been shown to reduce 90-day mortality. The pharmacist’s role on the PERT is not well defined. OBJECTIVES: Describe the pharmacist’s role as a PERT member and determine if pharmacists can improve time to anticoagulation and promote use of low molecular weight heparin (LMWH) instead of unfractionated heparin (UFH). METHODS: A retrospective, observational study of adult patients with massive or submassive PE between January 2014 and May 2020. Patient demographics, clinical variables, anticoagulation treatment/timing, and pharmacist activities during PERT response were evaluated. Patients were divided into three groups for comparisons (pre-PERT vs post-PERT with a pharmacist vs post-PERT without a pharmacist). Wilcoxon rank-sum or Kruskal-Wallis test and chi-squared analysis were used for continuous and categorical data, respectively. RESULTS: A total of 573 patients were included (mean age 63.2 ± 15.6 years, 54% male, 78% submassive PE); 137 in the pre-PERT and 436 in the post-PERT groups. Within the post-PERT group, 305 patients (70%) had a pharmacist as a member of the PERT, of which 222 (73%) had a documented pharmacotherapy-related intervention/activity. Most (n = 178, 58%) involved a pharmacist facilitating ordering/administration of an anticoagulant/thrombolytic. Median time from diagnosis to anticoagulation was significantly reduced in the post-PERT groups (pre-PERT: 104 minutes [IQR 124.5], post-PERT with a pharmacist: 63 minutes [IQR 84], post-PERT without a pharmacist: 75.5 minutes [IQR 113], P = .0001). More patients in the post-PERT groups received LMWH compared to UFH when a pharmacist was involved vs without a pharmacist (69.5% vs 53.3%, P = .0019) and major bleeding events were reduced (pre-PERT: 14.6%, post-PERT with a pharmacist: 4.6%, and post-PERT without a pharmacist: 9.9%, P = .0013) CONCLUSION: Pharmacists have an active role on the PERT and their involvement was associated with a shorter diagnosis to anticoagulation time, increased LMWH use, and fewer major bleeding events.

There are limited data on the association of smoking with the risk of stroke following left ventricular assist device (LVAD) implantation. We designed this study to analyze the impact of smoking status at the time of LVAD implantation on stroke. We hypothesized that current smokers are at increased risk of stroke when compared with patients who were former or never smokers. The study population comprised of 369 patients in the University of Rochester Medical Center LVAD database, implanted with an LVAD between 2008 and 2018. Patients were stratified as current smoker (smoking within 30 days before LVAD implantation), former smoker, and never smoker. Stroke was defined as a transient ischemic attack or cerebrovascular accident (hemorrhagic or ischemic). There were 45 current smokers, 198 former smokers, and 125 never smokers. Current smokers were younger (mean age 50 ± 11 years), as compared with former (58 ± 12 years) and never smokers (56 ± 13 years) p < 0.001. At 2 years following LVAD implantation, the cumulative incidence of stroke was significantly higher among current smokers (39%) as compared with former and never smokers (16% and 15%, respectively; p = 0.022 for the overall difference during follow-up). In a multivariate model adjusted for significant clinical variables, current smoking was associated with a significant 88% (p = 0.018) higher risk of stroke when compared with all noncurrent smokers. In conclusion, our data suggest that LVAD candidates who are current smokers experience a significantly higher risk of stroke following device implantation.

Current guidelines for primary implantable cardioverter-defibrillator (ICD) therapy do not account for sex differences in arrhythmic risk in ICD candidates.To evaluate the association between sex and risk of ventricular tachyarrhythmia (VTA) and mortality.This cohort study compared differences in the risk of VTA and mortality between 4506 men and women enrolled in the 4 Multicenter Automatic Defibrillator Implantation Trials (MADIT) between July 1, 1997, and December 31, 2011. Data from prospective randomized controlled multicenter studies were analyzed retrospectively. Men and women with an ICD or cardiac resynchronization therapy defibrillator who were enrolled in all MADIT studies were included. Data were analyzed between January 10 and June 10, 2021.ICD implant.The primary end point was sustained VTA, defined as ICD-recorded, treated or monitored VTA at least 170/min or ventricular fibrillation. Secondary VTA end points included VTA at least 200/min, appropriate ICD shocks, and appropriate antitachycardia pacing. All end points were included in a first and recurrent event analysis.Of the 4506 study participants, 3431 were men (76%). Mean (SD) age of the cohort was 64 (12) years. For women vs men, the mean (SD) age (64 [12] years vs 64 [11] years) and left ventricular ejection fraction (24% vs 25%) were similar, but women exhibited a higher frequency of nonischemic cardiomyopathy (454 of 1075 women [42%] vs 2535 of 3431 men [74%]). Women had significantly lower 3-year cumulative probability of sustained VTA (16% vs 26%), fast VTA (9% vs 17%), and appropriate ICD shocks (7% vs 15%) compared with men (P .001 for all). Multivariable analysis showed that female sex was independently associated with at least 40% lower risk of all first and recurrent VTA end points (P .001 for all), including the primary end point (first event, HR = 60 [95% CI, 50-73], P .001; recurrent event, HR = 49 [95% CI, 43-55], P .001), after accounting for the competing risk of all-cause mortality and nonarrhythmic mortality. The lower VTA risk associated with female sex was consistent in risk subsets but was significantly more pronounced in patients with nonischemic cardiomyopathy (female vs male in the ischemic group: hazard ratio, 0.73 [95% CI, 0.56-0.95], P = .02; nonischemic group: hazard ratio, 0.50 [95% CI, 0.38-0.66], P .001; P = .03 for interaction between female sex and cardiomyopathy).Findings suggest that women display a significantly lower risk of first and recurrent life-threatening VTA events than men, and that it is more pronounced in patients with nonischemic cardiomyopathy, suggesting a need for sex-specific risk assessment for primary prevention ICD therapy.

Right ventricular failure (RVF) remains one of the major causes of morbidity and mortality after left ventricular assist device (LVAD) implantation. We sought to compare immediate postoperative invasive hemodynamics and the risk of RVF following two different surgical approaches: less invasive surgery (LIS) versus full sternotomy (FS).The study population comprised all 231 patients who underwent implantation of a HeartMate 3 (Abbott) LVAD at our institution from 2015 to 2020, utilizing an LIS (n = 161; 70%) versus FS (n = 70; 30%) surgical approach. Outcomes included postoperative invasive hemodynamic parameters, vasoactive-inotropic score (VIS), RVF during index hospitalization, and 6-month mortality.Baseline clinical characteristics of the two groups were similar. Multivariate analysis showed that LIS, compared with FS, was associated with the improved cardiac index (CI) at the sixth postoperative hour (p = .036) and similar CI at 24 h, maintained by lower VIS at both timepoints (p = .002). The LIS versus FS approach was also associated with a three-fold lower incidence of in-hospital severe RVF (8.7% vs. 28.6%, p .001) and need for RVAD support (5.0% vs. 17.1%, p = .003), and with 68% reduction in the risk of 6-month mortality after LVAD implantation (Hazard ratio, 0.32; CI, 0.13-0.78; p = .012).Our findings suggest that LIS, compared with FS, is associated with a more favorable hemodynamic profile, as indicated by similar hemodynamic parameters maintained by lower vasoactive-inotropic support during the acute postoperative period. These findings were followed by a reduction in the risk of severe RVF and 6-month mortality in the LIS group.

The RAID (Ranolazine Implantable Cardioverter-Defibrillator) randomized placebo-controlled trial showed that ranolazine treatment was associated with reduction in recurrent ventricular tachycardia (VT) requiring appropriate implantable cardioverter-defibrillator (ICD) therapy.This study aimed to identify groups of patients in whom ranolazine treatment would result in the highest reduction of ventricular tachyarrhythmia (VTA) burden.Andersen-Gill analyses were performed to identify variables associated with risk for VTA burden among 1,012 patients enrolled in RAID. The primary endpoint was VTA burden defined as VTA episodes requiring appropriate treatment.Multivariate analysis identified 7 factors associated with increased VTA burden: history of VTA, age ≥65 years, New York Heart Association functional class ≥III, QRS complex (≥130 ms), low ejection fraction (30%), atrial fibrillation (AF), and concomitant antiarrhythmic drug (AAD) therapy. The effect of ranolazine on VTA burden was seen among patients without concomitant AAD therapy (HR [HR]: 0.68; 95% CI: 0.55-0.84; P 0.001), whereas no effect was seen among those who are concomitantly treated with other AADs (HR: 1.33; 95% CI: 0.90-1.96; P = 0.16); P = 0.003 for interaction. In patients with cardiac resynchronization therapy (CRT) ICDs, ranolazine treatment was associated with a 36% risk reduction for VTA recurrence (HR: 0.64; 95% CI: 0.47-0.86; P 0.001), whereas among patients with ICDs without CRT no significant effect was noted (HR: 0.94; 95% CI: 0.74-1.18; P = 0.57); P = 0.047 for interaction.In patients with high risk for VTA, ranolazine is effective in reducing VTA burden, with significantly greater effect in CRT-treated patients, those without AF, and those not treated with concomitant AADs. In patients already on AADs or those with AF, the addition of ranolazine did not affect VTA burden. (Ranolazine Implantable Cardioverter-Defibrillator Trial [RAID]; NCT01215253).

Low systolic blood pressure (SBP) was previously suggested to be a marker for heart failure and mortality in patients with low left ventricular ejection fraction. We aimed to explore the association of SBP on risk of ventricular tachyarrhythmias (VTA) and atrial arrhythmias as well as appropriate and inappropriate Implantable Cardioverter Defibrillator (ICD) therapy. The study population comprised 1,481 of 1,500 (99%) patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial – Reduce Inappropriate Therapy trial. Multivariate Cox proportional hazards regression modeling was used to identify the association of baseline SBP (recorded prior to ICD implantation) with the risk of VTA > 170 beats/min during follow-up (primary end point) and atrial arrhythmia, appropriate and inappropriate ICD therapy, hospitalization and death (secondary end points). SBP was dichotomized at 120 mm Hg (approximate mean and median) and was also assessed as a continuous measure. Multivariate analysis showed that each 10 mm Hg decrement in SBP was associated with corresponding 11% increased risk for VTA (p = 0.008). Low SBP (≤120 mm Hg) was associated with a significant 58% (p = 0.002) increased risk for VTA ≥170 beats/min; 53% (p = 0.019) increased risk for VTA ≥200 beats/min; and 65% (p = 0.001) increased risk for appropriate ICD therapy, as compared with SBP >120 mm Hg. Low SBP was not associated with increased risk of atrial arrhythmias, and inappropriate ICD therapy. In conclusion, in MADIT-RIT, SBP (≤120 mm Hg) predicted higher rates of VTA. These findings suggest that SBP may be utilized for VTA risk stratification in candidates for primary ICD therapy.

Background Alcohol septal ablation (ASA) in patients with hypertrophic cardiomyopathy (HCM) can lead to heart rhythm disturbances including complete heart block (CHB) and atrial and ventricular arrhythmias. Objective We aimed to evaluate the utility of long-term arrhythmia monitoring with an implantable cardiac monitor (ICM) after ASA. Methods Between February 2014 and March 2019, 56 patients with HCM undergoing ASA were enrolled in a prospective study and underwent ICM implantation. Kaplan-Meier survival analysis was used to assess the rate of ICM-detected arrhythmic events. Results The mean age was 59 ± 11 years, and 20 (36%) were women. The median (25th, 75th percentile) resting left ventricular outflow tract gradient obtained by echocardiography was 43 (22, 81) mm Hg. Greater than 1 septal perforating artery was injected in 48 patients (86%). The Kaplan-Meier cumulative rate of ICM-detected arrhythmic events at 18 months of follow-up was 71%, with an event rate of 43% occurring within 3 months of ASA. The cumulative rate of the ICM-detected first atrial fibrillation event at 18 months was 37%, and the corresponding rate of CHB was 19%. All atrial fibrillation and CHB events were actionable, leading to the initiation of anticoagulation and pacemaker implantation, respectively. No baseline demographic or procedural variables were identified as independent predictors of an increased risk of developing ICM-detected arrhythmic events. Conclusion After ASA, ICM is effective in capturing clinically actionable arrhythmic events in patients with HCM regardless of patient's baseline risk factors.