Age and sex differences in long-term outcomes following implantable cardioverter-defibrillator placement in contemporary clinical practice: findings from the Cardiovascular Research Network

Smoking status and the association between patient-level factors and survival among lung cancer patients

BACKGROUND

Declines in the prevalence of cigarette smoking, advances in targeted therapies, and implementation of lung cancer screening have changed the clinical landscape for lung cancer. The proportion of lung cancer deaths is increasing in those who have never smoked cigarettes. To better understand contemporary patterns in survival among patients with lung cancer, a comprehensive evaluation of factors associated with survival, including differential associations by smoking status, is needed.

METHODS

Patients diagnosed with lung cancer between January 1, 2010, and September 30, 2019, were identified. We estimated all-cause and lung cancer-specific median, 5-year, and multivariable restricted mean survival time (RMST) to identify demographic, socioeconomic, and clinical factors associated with survival, overall and stratified by smoking status (never, former, and current).

RESULTS

Analyses included 6813 patients with lung cancer: 13.9% never smoked, 54.2% formerly smoked, and 31.9% currently smoked. All-cause RMST through 5 years for those who never, formerly, and currently smoked was 32.1, 25.9, and 23.3 months, respectively. Lung cancer-specific RMST was 36.3 months, 30.3 months, and 26.0 months, respectively. Across most models, female sex, younger age, higher socioeconomic measures, first-course surgery, histology, and body mass index were positively associated, and higher stage was inversely associated with survival. Relative to White patients, Black patients had increased survival among those who formerly smoked.

CONCLUSIONS

We identify actionable factors associated with survival between those who never, formerly, and currently smoked cigarettes. These findings illuminate opportunities to address underlying mechanisms driving lung cancer progression, including use of first-course treatment, and enhanced implementation of tailored smoking cessation interventions for individuals diagnosed with cancer.

Sex differences in Cardiac electronic device implantation: Outcomes from an Australian multi-centre clinical quality registry

Background

There is uncertainty regarding whether outcomes after Cardiac Implantable Electronic Devices (CIED) differ between women and men. There are no prospectively collected data regarding Australian CIED outcomes. This study aimed to determine whether the characteristics and outcomes of Australian patients undergoing CIED implantation differ by sex.

Methods

We prospectively followed 5,360 patients undergoing CIED implantation between 2015 and 2019 in a large multi-centre Australian registry. Patient characteristics, procedural data, medications and clinical outcomes to 1 year were analysed.

Results

The mean age was 76.2 + 11.2 years, and 2022 (37.7%) were female. Women were older than men at device implantation (77.0 ± 11.6 years vs. 75.5 ± 10.9 years, p < 0.001). Most implants were de novo (79.7%). Pacing was more commonly for sick sinus syndrome in women than men (54.4% vs. 47.2%, p < 0.001) and less often for A-V block (28.3% vs. 35.1%, p < 0.001). Adverse events at 30 days were low compared to international cohorts, for mortality (0.06%) and major complications (0.6%). There were no significant sex differences (women vs. men) for death (HR 1.33, 95% CI 0.58–3.13, p = 0.49) or major complications (HR 1.41, 95% 95% CI 0.65–3.03, p = 0.39). At 1-year, there was no difference in major complications or risk-adjusted all-cause mortality (HR 1.05, 95% CI 0.70–1.29, p = 0.77) between women and men.

Conclusions

Clinical practice and 30-day outcomes after CIED implantation in Australia are consistent with international reports. There were no differences in procedural complication rates or clinical outcomes at 1-year between women and men, regardless of age or CIED system implanted.

Development and external validation of prognostic models to predict sudden and pump-failure death in patients with HFrEF from PARADIGM-HF and ATMOSPHERE

Background

Sudden death (SD) and pump failure death (PFD) are the two leading causes of death in patients with heart failure and reduced ejection fraction (HFrEF).

Objective

Identifying patients at higher risk for mode-specific death would allow better targeting of individual patients for relevant device and other therapies.

Methods

We developed models in 7156 patients with HFrEF from the Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure (PARADIGM-HF) trial, using Fine-Gray regressions counting other deaths as competing risks. The derived models were externally validated in the Aliskiren Trial to Minimize Outcomes in Patients with Heart Failure (ATMOSPHERE) trial.

Results

NYHA class and NT-proBNP were independent predictors for both modes of death. The SD model additionally included male sex, Asian or Black race, prior CABG or PCI, cancer history, MI history, treatment with LCZ696 vs. enalapril, QRS duration and ECG left ventricular hypertrophy. While LVEF, ischemic etiology, systolic blood pressure, HF duration, ECG bundle branch block, and serum albumin, chloride and creatinine were included in the PFD model. Model discrimination was good for SD and excellent for PFD with Harrell’s C of 0.67 and 0.78 after correction for optimism, respectively. The observed and predicted incidences were similar in each quartile of risk scores at 3 years in each model. The performance of both models remained robust in ATMOSPHERE.

Conclusion

We developed and validated models which separately predict SD and PFD in patients with HFrEF. These models may help clinicians and patients consider therapies targeted at these modes of death.

Trial registration number

PARADIGM-HF: ClinicalTrials.gov NCT01035255, ATMOSPHERE: ClinicalTrials.gov NCT00853658.

Graphics abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01888-x.

Surveys and Registries on Catheter Ablation of Atrial Fibrillation: Fifteen Years of History

Surveys and registries are widely used in medicine as valuable tools to integrate the information from randomized and observational studies. Early after its introduction in daily practice and parallel to its escalating popularity, catheter ablation of atrial fibrillation has been the subject of several surveys and registries. Over the years, relevant aspects associated with atrial fibrillation ablation have been investigated using these tools, including procedural safety and efficacy, discontinuation of anticoagulation therapy and risk of stroke postablation, and outcomes in special populations. The aim of this article is to provide a comprehensive review of the contributions offered by surveys and registries in catheter ablation of atrial fibrillation over the past 15 years.

Sex-specific differences in access and response to medical and device therapies in heart failure: State of the art

Women with heart failure (HF) are more symptomatic than their male counterparts. Despite deriving similar benefits from both medical and devices therapies, women continue to be underrepresented in clinic trials. Important sex-based disparities exist in enrollment in clinical trials and access to medical and device-based therapies, in part stemming from differences in medical and psychosocial comorbidities. Disparities in access to beneficial interventions likely contribute to the greater symptom burden identified in women with HF. Improved focus on the enrollment of women in clinical trials will allow a better understanding of the underpinnings of these disparities and improve the care of women with HF.

Research Needs and Priorities for Catheter Ablation of Atrial Fibrillation: A Report From a National Heart, Lung, and Blood Institute Virtual Workshop

Catheter ablation has brought major advances in the management of patients with atrial fibrillation (AF). As evidenced by multiple randomized trials, AF catheter ablation can reduce the risk of recurrent AF and improve quality of life. In some studies, AF ablation significantly reduced cardiovascular hospitalizations. Despite the existing data on AF catheter ablation, numerous knowledge gaps remain concerning this intervention. This report is based on a recent virtual workshop convened by the National Heart, Lung, and Blood Institute to identify key research opportunities in AF ablation. We outline knowledge gaps related to emerging technologies, the relationship between cardiac structure and function and the success of AF ablation in patient subgroups in whom clinical benefit from ablation varies, and potential platforms to advance clinical research in this area. This report also considers the potential value and challenges of a sham ablation randomized trial. Prioritized research opportunities are identified and highlighted to empower relevant stakeholders to collaborate in designing and conducting effective, cost-efficient, and transformative research to optimize the use and outcomes of AF ablation.

Sex-related differences in chronic heart failure

The prevalence of chronic heart failure (CHF) is steadily increasing. Both sexes are affected, with significant differences in etiology, epidemiology and clinical presentation, prognosis, comorbidities, and response to treatment. Women tend to develop CHF at a more advanced age, present more often with HF with preserved ejection fraction, are more symptomatic, and have a worse quality of life than men, but also a better prognosis. In women, CHF has more frequently a non-ischemic etiology, and arterial hypertension and diabetes mellitus are leading comorbidities. Furthermore, many sex-related differences have been detected in the response to treatment, for example a greater prognostic benefit from angiotensin-receptor blockers in women, a higher incidence of complications after defibrillator implantation, and a greater response to cardiac resynchronization therapy. Furthermore, women are less likely to receive defibrillator therapy or heart transplantation. The significant underrepresentation of women in clinical trials limits our capacity to evaluate the extent of sex-related differences in CHF, although their characterization seems crucial in order to achieve the ultimate goal of a tailored therapy for this condition.

Sex Differences in the Management of Advanced Heart Failure

PURPOSE OF REVIEW

Heart failure (HF) is prevalent among women and remains a leading cause of morbidity and mortality in the United States. Currently, 3 million women live with HF and the prevalence is projected to continue to increase. The purpose of this review is to highlight sex differences in the use and response to evidence-based pharmacological, device, and advanced HF therapies, as well as explore emerging areas of research in sex differences in the treatment of HF.

RECENT FINDINGS

Under-representation of women in clinical HF trials has limited our understanding of sex-related differences in the treatment and outcomes of HF. Important sex differences exist in the use of evidence-based HF therapies and clinical response among women with HF. In general, women tend to obtain the same clinical benefit from evidence-based HF drug and device therapies, but the utilization rates of guideline-directed medical therapies remain poor compared to men. Future research efforts should focus on increasing the enrollment of women in HF trials to help gain helpful insight into sex-specific differences in treatment effects and subsequent clinical outcomes.

Cardiac implantable electrical devices in women

Clinical trials have demonstrated the benefits of cardiac implantable electrical devices, which include pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT), with respect to key clinical outcomes and survival. Women more often require permanent pacing for sick sinus syndrome, whereas atrioventricular block is more common in men. Women appear to have a higher incidence of complications with pacemaker implantation, as well as with ICD and CRT implantation. The indications for ICDs and CRT do not have any distinctions based on sex, and outcomes are comparable in men and women. In fact, women often seem to have better outcomes with CRT compared with men. Despite the demonstrated benefits of these devices, ICDs and CRT are underutilized in women. In this review, we explore sex differences in utilization, outcomes, and complications with pacemakers, ICDs, and CRT.

Sex Differences in Heart Failure

Heart failure (HF) represents a global pandemic health problem with a high impact on health-care costs, affecting about 26 million adults worldwide. The overall HF prevalence and incidence are ~2% and ~0.2% per year, respectively, in Western countries, with half of the HF population with reduced ejection fraction (HFpEF) and half with preserved (HFpEF) or mid-range ejection fraction (HFmrEF). Sex differences may exist in HF. More males have HFrEF or HFmrEF and an ischemic etiology, whereas more females have HFpEF and hypertension, diastolic dysfunction, and valvular pathologies as HF etiologies. Females are generally older, have a higher EF, higher frequency of HF-related symptoms, and lower NYHA functional status. Generally, it is observed that female HF patients tend to have more comorbidities such as atrial fibrillation, diabetes, hypertension, anemia, iron deficiency, renal disease, arthritis, frailty, depression, and thyroid abnormalities. However, overall, females have better prognosis in terms of mortality and hospitalization risk compared with men, regardless of EF. Potential sex differences in HF characteristics may be underestimated because of the underrepresentation of females in cardiovascular research and, in particular, the sex imbalance in clinical trial enrollment may avoid to identify sex-specific differences in treatments' benefit.

Predictors of mortality and ICD shock therapy in primary prophylactic ICD patients-A systematic review and meta-analysis

Background

There is evidence that the benefit of a primary prophylactic ICD therapy is not equal in all patients.

Purpose

To evaluate risk factors of appropriate shocks and all- cause mortality in patients with a primary prophylactic ICD regarding contemporary studies.

Data source

PubMed, LIVIVO, Cochrane CENTRAL between 2010 and 2016.

Study selection

Studies were eligible if at least one of the endpoints of interest were reported.

Data extraction

All abstracts were independently reviewed by at least two authors. The full text of all selected studies was then analysed in detail.

Data synthesis

Our search strategy retrieved 608 abstracts. After exclusion of unsuitable studies, 36 papers with a total patient number of 47282 were included in our analysis. All-cause mortality was significantly associated with increasing age (HR 1.41, CI 1.29–1.53), left ventricular function (LVEF; HR 1.21, CI 1.14–1.29), ischemic cardiomyopathy (ICM; HR 1.37, CI 1.14–1.66) and co-morbidities such as impaired renal function (HR 2.30, CI 1.97–2.69). Although, younger age (HR 0.96, CI 0.85–1.09), impaired LVEF (HR 1.26, CI 0.89–1.78) and ischemic cardiomyopathy (HR 2.22, CI 0.83–5.93) were associated with a higher risk of appropriate shocks, none of these factors reached statistical significance.

Limitations

Individual patient data were not available for most studies.

Conclusion

In this meta-analysis of contemporary clinical studies, all-cause mortality is predicted by a variety of clinical characteristics including LVEF. On the other hand, the risk of appropriate shocks might be associated with impaired LVEF and ischemic cardiomyopathy. Further prospective studies are required to verify risk factors for appropriate shocks other than LVEF to help select appropriate patients for primary prophylactic ICD-therapy.

Non-ischaemic cardiomyopathy, sudden death and implantable defibrillators: a review and meta-analysis

OBJECTIVE

The recent Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH) trial suggested that implantable cardioverter defibrillators (ICDs) do not reduce overall mortality in patients with non-ischaemic cardiomyopathy (NICM), despite reducing sudden cardiac death. We performed an updated meta-analysis to examine the impact of ICD therapy on mortality in NICM patients.

METHODS

A systematic search for studies that examined the effect of ICDs on outcomes in NICM was performed. Our analysis compared patients randomised to an ICD with those randomised to no ICD, and examined the endpoint of overall mortality.

RESULTS

Six primary prevention trials and two secondary prevention trials were identified that met the pre-specified search criteria. Using a fixed-effects model, analysis of primary prevention trials revealed a reduction in overall mortality with ICD therapy (RR 0.76, 95% CI 0.65 to 0.91).

CONCLUSIONS

Although our updated meta-analysis demonstrates a survival benefit of ICD therapy, the effect is substantively weakened by the inclusion of the DANISH trial-which is both the largest and most recent of the analysed trials-indicating that the residual pooled benefit of ICDs may reflect the risk of sudden death in older trials which included patients treated sub-optimally by contemporary standards. As such, these data must be interpreted cautiously. The results of the DANISH trial emphasise that there is no 'one size fits all' indication for primary prevention ICDs in NICM patients, and clinicians must consider age and comorbidity on an individual basis when determining whether a defibrillator is appropriate.

Atrial Fibrillation and Ventricular Arrhythmias: Sex Differences in Electrophysiology, Epidemiology, Clinical Presentation, and Clinical Outcomes

Sex-specific differences in the epidemiology, pathophysiology, clinical presentation, clinical treatment, and clinical outcomes of atrial fibrillation (AF), sustained ventricular arrhythmias, and sudden cardiac death are recognized. Sex hormones cause differences in cardiac electrophysiological parameters between men and women that may affect the risk for arrhythmias. The incidence and prevalence of AF is lower in women than in men. However, because women live longer and AF prevalence increases with age, the absolute number of women with AF exceeds that of men. Women with AF are more symptomatic, present with more atypical symptoms, and report worse quality of life in comparison with men. Female sex is an independent risk factor for death or stroke attributable to AF. Oral anticoagulation therapy for stroke prevention has similar efficacy for men and women, but older women treated with warfarin have a higher residual risk of stroke in comparison with men. Women with AF are less likely to receive rhythm control antiarrhythmic drug therapy, electric cardioversion, or catheter ablation in comparison with men. The incidence and prevalence of sustained ventricular arrhythmias and sudden cardiac death are lower in women than in men. Women receiving implantable cardioverter defibrillators for primary prevention of sudden cardiac death are less likely to experience sustained ventricular arrhythmias in comparison with men. In contrast, women receiving a cardiac resynchronization therapy implantable cardioverter defibrillator for the treatment of heart failure are more likely to benefit than men. Women are less likely to be referred for implantable cardioverter defibrillator therapy despite current guideline recommendations. Women are more likely to experience a significant complication related to implantable cardioverter defibrillator implantation in comparison with men. Whether sex differences in treatment decisions reflect patient preferences or treatment biases requires further study.

[ICD in elderly patients]

Treatment with an implantable cardioverter-defibrillator (ICD) represents a prognostic but not symptomatic therapy. It should therefore be restricted to patients where an improvement of prognosis is possible and reasonable. ICD implantation should only be performed in patients with a life expectancy of at least 1 year at reasonable quality of life. The decision in which patient improvement of prognosis is no longer a desirable target is problematic, both medically and ethically. It is not entirely clear in which elderly patient an ICD therapy can convey prognostic benefit despite comorbidity and competitive life-threatening diseases, as it is unclear how old age should be defined. In primary prophylaxis of sudden cardiac death, data on a prognostic benefit of the ICD in elderly patients are less clear than in secondary prophylaxis since short-term mortality due to other causes is higher in the elderly. However, elderly ICD patients have a similar rate of appropriate ICD therapy as younger patients. Complications at ICD implantation or long-term lead failure do not occur more frequently in elderly patients and therefore do not represent a reason to withhold ICD implantation in elderly patients or to set an age limit above which ICD implantation should no longer be performed. The ICD indication in elderly patients should be individualized depending on remaining life expectancy, comorbidity, "biological age" and patient preferences which play a particularly important role in elderly patients. Aspects of a potential improvement in quality of life by the ICD which may also serve as a system for antibradycardiac or resynchronization treatment should be included into considerations. Deactivation of at least shock therapy should be discussed in elderly patients fitted with an ICD if the subject is brought up by the patient or if clinical deterioration suggests the need to talk about a "do not resuscitate" order. This talk should be performed before death is imminent and before an electrical storm in terminal illness leads to multiple shocks by the active device.

Gender Differences in Appropriate Shocks and Mortality among Patients with Primary Prophylactic Implantable Cardioverter-Defibrillators: Systematic Review and Meta-Analysis

Background

Some but not all prior studies have shown that women receiving a primary prophylactic implantable cardioverter defibrillator (ICD) have a lower risk of death and appropriate shocks than men.

Purpose

To evaluate the effect of gender on the risk of appropriate shock, all-cause mortality and inappropriate shock in contemporary studies of patients receiving a primary prophylactic ICD.

Data Source

PubMed, LIVIVO, Cochrane CENTRAL between 2010 and 2016.

Study Selection

Studies providing at least 1 gender-specific risk estimate for the outcomes of interest.

Data Extraction

Abstracts were screened independently for potentially eligible studies for inclusion. Thereby each abstract was reviewed by at least two authors.

Data Synthesis

Out of 680 abstracts retained by our search strategy, 20 studies including 46’657 patients had gender-specific information on at least one of the relevant endpoints. Mean age across the individual studies varied between 58 and 69 years. The proportion of women enrolled ranged from 10% to 30%. Across 6 available studies, women had a significantly lower risk of first appropriate shock compared with men (pooled multivariable adjusted hazard ratio 0.62 (95% CI [0.44; 0.88]). Across 14 studies reporting multivariable adjusted gender-specific hazard ratio estimates for all-cause mortality, women had a lower risk of death than men (pooled hazard ratio 0.75 (95% CI [0.66; 0.86]). There was no statistically significant difference for the incidence of first inappropriate shocks (3 studies, pooled hazard ratio 0.99 (95% CI [0.56; 1.73]).

Limitations

Individual patient data were not available for most studies.

Conclusion

In this large contemporary meta-analysis, women had a significantly lower risk of appropriate shocks and death than men, but a similar risk of inappropriate shocks. These data may help to select patients who benefit from primary prophylactic ICD implantation.

Long-Term Evaluation of Biotronik Linox and Linox(smart) Implantable Cardioverter Defibrillator Leads

INTRODUCTION

Expert consensus holds that post-market, systematic surveillance of ICD leads is essential to ensure confirmation of adequate lead performance. GALAXY (NCT00836589) and CELESTIAL (NCT00810264) are ongoing multicenter, prospective, non-randomized registries conducted to confirm the long-term safety and reliability of Biotronik leads.

METHODS AND RESULTS

ICD and CRT-D patients are followed for Linox and Linox(smart) ICD lead performance and safety for 5 years post-implant. All procedural and system-related adverse events (AEs) were assessed at each follow-up, along with lead electrical parameters. An independent CEC of EPs adjudicated AEs to determine AE category and lead relatedness. The analysis used categories of lead observations per ISO 5841-2 (Third edition). A total of 3,933 leads were implanted in 3,840 patients (73.0% male, mean age 67.0 ± 12.2 years) at 146 US centers. The estimated cumulative survival probability was 96.3% at 5 years after implant for Linox leads and 96.6% at 4 years after implant for Linox(smart) leads. A comparison of the Linox and Linox(smart) survival functions did not find evidence of a difference (P = 0.2155). The most common AEs were oversensing (23, 0.58%), conductor fracture (14, 0.36%), failure to capture (13, 0.33%), lead dislodgement (12, 0.31%), insulation breach (10, 0.25%), and abnormal pacing impedance (8, 0.20%).

CONCLUSIONS

Linox and Linox(smart) ICD leads are safe, reliable and infrequently associated with lead-related AEs. Additionally, estimated cumulative survival probability is clinically acceptable and well within industry standards. Ongoing data collection will confirm the longer-term safety and performance of the Linox family of ICD leads.