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

Differences in presentation, diagnosis and management of heart failure in women. A scientific statement of the Heart Failure Association of the ESC

Despite the progress in the care of individuals with heart failure (HF), important sex disparities in knowledge and management remain, covering all the aspects of the syndrome, from aetiology and pathophysiology to treatment. Important distinctions in phenotypic presentation are widely known, but the mechanisms behind these differences are only partially defined. The impact of sex-specific conditions in the predisposition to HF has gained progressive interest in the HF community. Under-recruitment of women in large randomized clinical trials has continued in the more recent studies despite epidemiological data no longer reporting any substantial difference in the lifetime risk and prognosis between sexes. Target dose of medications and criteria for device eligibility are derived from studies with a large predominance of men, whereas specific information in women is lacking. The present scientific statement encompasses the whole scenario of available evidence on sex-disparities in HF and aims to define the most challenging and urgent residual gaps in the evidence for the scientific and clinical HF communities.

Sex differences among subcutaneous implantable cardioverter-defibrillator recipients: a propensity-matched, multicentre, international analysis from the i-SUSI project

AIMS

Women have been historically underrepresented in implantable cardioverter-defibrillator (ICD) trials. No data on sex differences regarding subcutaneous ICDs (S-ICD) carriers have been described. Aim of our study was to investigate sex-related differences among unselected S-ICD recipients.

METHODS AND RESULTS

Consecutive patients enrolled in the multicentre, international i-SUSI registry were analysed. Comparisons between sexes were performed using a 1:1 propensity matching adjusted analysis for age, body mass index (BMI), left ventricular function, and substrate. The primary outcome was the rate of appropriate shocks during follow-up. Inappropriate shocks and other device-related complications were deemed secondary outcomes. A total of 1698 patients were extracted from the i-SUSI registry; 399 (23.5%) were females. After propensity matching, two cohorts of 374 patients presenting similar baseline characteristics were analysed. Despite similar periprocedural characteristics and a matched BMI, women resulted at lower risk of conversion failure as per PRAETORIAN score (73.4% vs. 81.3%, P = 0.049). Over a median follow-up time of 26.5 [12.7-42.5] months, appropriate shocks were more common in the male cohort (rate/year 3.4% vs. 1.7%; log-rank P = 0.049), while no significant differences in device-related complications (rate/year: 6.3% vs. 5.8%; log-rank P = 0.595) and inappropriate shocks (rate/year: 4.3% vs. 3.1%; log-rank P = 0.375) were observed. After controlling for confounders, sex remained significantly associated with the primary outcome (aHR 1.648; CI 0.999-2.655, P = 0.048), while not resulting predictor of inappropriate shocks and device-related complications.

CONCLUSION

In a propensity-matched cohort of S-ICD recipients, women are less likely to experience appropriate ICD therapy, while not showing higher risk of device-related complications.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT0473876.

"Real-world" analysis of battery longevity of implantable cardioverter-defibrillators: an in-depth analysis of a prospective defibrillator database

BACKGROUND

There is a lack of evidence regarding contemporary implantable cardioverter-defibrillator (ICD) battery longevity. Our aim was to assess battery longevity in ICDs in a real-world setting.

METHODS

Retrospective cross-sectional single center study of a prospectively collected database of consecutive patients who underwent ICD implantation from January 2010 to December 2015. Clinical data and battery longevity of all manufacturers were collected.

RESULTS

A total of 351 patients (84.6% males, mean age of 61 ± 12 years) were included in the study (292 VVI; 6 VDD; 53 DDD). All manufacturers (Abbott, Biotronik, Boston, Medtronic and Microport) were equally represented in the study (p = 0.110). Median battery longevity was 10.8 years (11 years for VVI and 8.5 for DDD). After a follow-up time of 5 years, 98% of VVI and DDD were still in service (vs. industry-projected longevity of 98%). During this time, 89 patients (25.4%) underwent device replacement - 69 patients (77.5%) due to battery depletion, 6 patients due to infection, 3 patients due to dysfunction and 13 patients due to upgrade to CRT-D. Patients with Medtronic or Biotronik ICDs had a greater probability of being replaced earlier due to battery depletion (Biotronik HR 6.87, 95% CI 2.54-18.58, p < 0.001; Medtronic HR 6.08, 95% CI 2.45-15.06 p < 0.001).

CONCLUSIONS

VVI and DDD ICD battery longevity matched industry-projected longevity after 5 years of follow-up. Medtronic and Biotronik ICDs appeared to have an earlier battery depletion. Further randomized studies are required to ensure optimal care.

Disparities in Referral and Utilization of Implantable Cardioverter-Defibrillators for Primary Prevention of Sudden Cardiac Death

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) reduce mortality in patients with reduced left ventricular ejection fraction (LVEF). We investigated sex disparities in a contemporary Canadian population for utilization of primary prevention ICDs.

METHODS

This was a retrospective cohort study on patients with reduced LVEF admitted to hospitals from 2010 to 2020 in Nova Scotia (population = 971,935).

RESULTS

There were 4406 patients eligible for ICDs: 3108 (71%) men and 1298 (29%) women. The mean follow-up time was 3.9 ± 3.0 years. Rates of coronary disease were similar between men and women (45.8% vs 44.0%; P = 0.28), but men had lower LVEF (26.6 ± 5.9% vs 27.2 ± 5.8%; P = 0.0017). The referral rate for ICD was 11% (n = 487), with 13% of men (n = 403) and 6.5% of women (n = 84) referred (P < 0.001). The ICD implantation rate in the population was 8% (n = 358), with 9.5% of men (n = 296) and 4.8% of women (n = 62) (P < 0.001) receiving the device. Men were more likely than women to receive an ICD (odds ratio 2.08, 95% confidence interval 1.61-2.70; P < 0.0001)). There was no significant difference in mortality between men and women (P = 0.2764). There was no significant difference in device therapies between men and women (43.8% vs 31.1%; P = 0.0685).

CONCLUSIONS

A significant disparity exists in the utilization of primary prevention ICDs between men and women in a contemporary Canadian population.

Sex differences in the course of implantable cardioverter defibrillator concerns (Results from the Danish national DEFIB-WOMEN study)

OBJECTIVE

The implantable cardioverter defibrillator (ICD) is used to treat malignant ventricular arrhythmias. Since 33% of patients experience ICD-related concerns, we examined sex differences in ICD concerns and correlates of ICD concerns during 24 months of follow-up after implantation of an ICD.

METHODS

Patients from the DEFIB-WOMEN study (n = 1515; 81.6% male patients) completed questionnaires on ICD concerns, anxiety, depression, and Type D personality at five measure points (baseline, 3-, 6-, 12- and 24-months post-implantation).

RESULTS

Male patients scored on average 7.0 (6.8) points on ICD concerns at the time of implantation and female patients scored on average 10.5 (8.2) points. We found statistically significant sex differences in ICD concerns at all measurement points, with female patients scoring 2.77 points (8.7% of the maximum score of 32) higher than male patients. ICD concerns decreased in both sexes the first 6 months and then levelled out. For both sexes, ICD concerns at baseline were significantly correlated with ICD concerns at 24-months follow-up. Anxiety at baseline was correlated with ICD concerns in female patients, while depression at baseline and at least one experienced shock correlated with ICD concerns in male patients.

CONCLUSION

Female patients reported more ICD concerns at all measurement points compared to male patients, but for both sexes ICD concerns decreased in the first 6 months. ICD shock, anxiety, depression, and ICD concerns at baseline were correlates of ICD concerns at 24-months follow-up.

Sex-Related Differences in Patient Selection for and Outcomes after Pace and Ablate for Refractory Atrial Fibrillation: Insights from a Large Multicenter Cohort

Background: A pace and ablate strategy may be performed in refractory atrial fibrillation with rapid ventricular response. Objective: We aimed to assess sex-related differences in patient selection and clinical outcomes after pace and ablate. Methods: In a retrospective multicentre study, patients undergoing AV junction ablation were studied. Sex-related differences in baseline characteristics, all-cause mortality, heart failure (HF) hospitalizations, and device-related complications were assessed. Results: Overall, 513 patients underwent AV junction ablation (median age 75 years, 50% men). At baseline, men were younger (72 vs. 78 years, p < 0.001), more frequently had non-paroxysmal AF (82% vs. 72%, p = 0.006), had a lower LVEF (35% vs. 55%, p < 0.001) and more frequently had cardiac resynchronization therapy (75% vs. 25%, p < 0.001). Interventional complications were rare in both groups (1.2% vs. 1.6%, p = 0.72). Patients were followed for a median of 42 months in survivors (IQR 22−62). After 4 years of follow-up, the combined endpoint of all-cause death or HF hospitalization occurred more often in men (38% vs. 27%, p = 0.008). The same was observed for HF hospitalizations (22% vs. 11%, p = 0.021) and all-cause death (28% vs. 21%, p = 0.017). Sex category remained an independent predictor of death or HF hospitalization after adjustment for age, LVEF and type of stimulation. Lead-related complications, infections, and upgrade to ICD or CRT occurred in 2.1%, 0.2% and 3.5% of patients, respectively. Conclusions: Pace and ablate is safe with a need for subsequent device-related re-interventions in 5.8% over 4 years. We found significant sex-related differences in patient selection, and women had a more favourable clinical course after AV junction ablation.

Comparison of Frequency of Ventricular Tachyarrhythmia in Men-Versus-Women in Patients with Implantable Cardioverter-Defibrillator for Primary Prevention

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; p <0.001 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.

Sex Differences in the Risk of First and Recurrent Ventricular Tachyarrhythmias Among Patients Receiving an Implantable Cardioverter-Defibrillator for Primary Prevention

Importance

Current guidelines for primary implantable cardioverter-defibrillator (ICD) therapy do not account for sex differences in arrhythmic risk in ICD candidates.

Objective

To evaluate the association between sex and risk of ventricular tachyarrhythmia (VTA) and mortality.

Design, Setting, and Participants

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.

Exposures

ICD implant.

Main Outcomes and Measures

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.

Results

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).

Conclusions and Relevance

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.

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

Aims

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

Method and results

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

Conclusion

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

Arrhythmias in Female Patients: Incidence, Presentation and Management

There is a growing appreciation for differences in epidemiology, treatment, and outcomes of cardiovascular conditions by sex. Historically, cardiovascular clinical trials have under-represented females, but findings have nonetheless been applied to clinical care in a sex-agnostic manner. Thus, much of the collective knowledge about sex-specific cardiovascular outcomes result from post hoc and secondary analyses. In some cases, these investigations have revealed important sex-based differences with implications for optimizing care for female patients with arrhythmias. This review explores the available evidence related to cardiac arrhythmia care among females, with emphasis on areas in which important sex differences are known or suggested. Considerations related to improving female enrollment in clinical trials as a way to establish more robust clinical evidence for the treatment of females are discussed. Areas of remaining evidence gaps are provided, and recommendations for areas of future research and specific action items are suggested. The overarching goal is to improve appreciation for sex-based differences in cardiac arrhythmia care as 1 component of a comprehensive plan to optimize arrhythmia care for all patients.

Present criteria for prophylactic ICD implantation: Insights from the EU-CERT-ICD (Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators in EUrope) project

BACKGROUND

The clinical effectiveness of primary prevention implantable cardioverter defibrillator (ICD) therapy is under debate. It is urgently needed to better identify patients who benefit from prophylactic ICD therapy. The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators (EU-CERT-ICD) completed in 2019 will assess this issue.

SUMMARY

The EU-CERT-ICD is a prospective investigator-initiated non-randomized, controlled, multicenter observational cohort study done in 44 centers across 15 European countries. A total of 2327 patients with heart failure due to ischemic heart disease or dilated cardiomyopathy indicated for primary prophylactic ICD implantation were recruited between 2014 and 2018 (>1500 patients at first ICD implantation, >750 patients non-randomized non-ICD control group). The primary endpoint was all-cause mortality, and first appropriate shock was co-primary endpoint. At baseline, all patients underwent 12‑lead ECG and Holter-ECG analysis using multiple advanced methods for risk stratification as well as documentation of clinical characteristics and laboratory values. The EU-CERT-ICD data will provide much needed information on the survival benefit of preventive ICD therapy and expand on previous prospective risk stratification studies which showed very good applicability of clinical parameters and advanced risk stratifiers in order to define patient subgroups with above or below average ICD benefit.

CONCLUSION

The EU-CERT-ICD study will provide new and current data about effectiveness of primary prophylactic ICD implantation. The study also aims for improved risk stratification and patient selection using clinical risk markers in general, and advanced ECG risk markers in particular.

Subcutaneous implantable cardioverter-defibrillator in primary and secondary prevention of sudden cardiac death: A meta-analysis

BACKGROUND

Subcutaneous implantable cardioverter-defibrillator (S-ICD) is gaining in popularity for primary and secondary prevention of sudden cardiac death. The objective was to evaluate the safety and clinical effectiveness of the S-ICD for prevention of sudden cardiac death compared to transvenous cardioverter-defibrillator (TV-ICD).

METHODS

A systematic review with meta-analyses was performed. The electronic databases MEDLINE, EMBASE, SCI, and Cochrane Central Register of Controlled Trials were consulted in March 2018 with no restrictions on publication date. Predefined criteria were used to determine inclusion of studies and to assess their methodologic quality.

RESULTS

Ten longitudinal-observational studies with comparison group presenting moderate methodologic flaws were included (N = 7820). The combination of results indicates that health-related quality of life is not significantly different between S-ICD and TV-ICD groups (Physical health: MD = 2.90; 95% CI = -3.88, 9.68/Mental health: MD = 0.13; 95% CI = -2.11, 2.37). Mortality occurred in 4.4% of S-ICD patients and 5.9% of TV-ICD patients died (OR = 0.79; 95% CI = 0.50, 1.24). The incidence of infections (OR = 1.79; 95% CI = 0.93, 3.43) and inappropriate shocks (OR = 1.28, 95% CI = 0.91, 1.78) is not significantly different between both groups. The S-ICD reduces complications related to electrodes/leads (OR = 0.13, 95% CI = 0.05, 0.29) and has lower electrodes/leads movement compared with TV-ICD (OR = 0.26; 95% CI 0.10, 0.67). In contrast, pneumothorax is more likely in TV-ICD than S-ICD (OR = 0.17; 95% CI = 0.03, 0.97).

CONCLUSIONS

S-ICD reduces electrodes/leads movement, electrodes/leads related complications, and pneumothorax. Our study did not demonstrate a statistically significant difference in mortality, health-related quality of life, and infection rate between S-ICD and TV-ICD.

Sex difference in inappropriate therapy and survival among 1471 implantable cardioverter-defibrillator recipients

Introduction

To assess a potential relationship between sex and outcome in recipients of an implantable cardioverter‐defibrillator (ICD).

Methods and Results

All 1471 ICD recipients between 2000 and 2015 were sex‐related analyzed with the following outcome parameters: overall survival (OS), the occurrence of inappropriate and appropriate antitachycardia pacing (ATP), and shock therapy. We followed 1206 (82%) male and 265 (18%) female ICD recipients during 4.1 ± 3.6 and 4.3 ± 3.8 years, respectively, (P = .369). Kaplan‐Meier analysis revealed that there was no significant difference in OS between female and male patients (P = .132). After adjustment for relevant confounding factors in a multivariate model, sex remained a nonsignificant predictor of overall mortality (hazard ratio [male] = 1.11; P = .493). Negative binomial regression analysis revealed that women received less appropriate ATP therapy (rate ratio [RR] = 0.37; P = .043), whereas rates of appropriate shock therapy (RR = 1.95; P = .369) did not differ between women and men. No significant differences were observed in the occurrence of inappropriate ATP (RR = 1.22; P = .715) and inappropriate shock therapy (RR = 0.64; P = .121).

Conclusion

Female and male patients equally benefit from ICD therapy in terms of OS. Women are less likely to receive appropriate ATP therapy, whereas appropriate shock and inappropriate ATP and shock therapy are independent of sex.

Rationale and design of the EU-CERT-ICD prospective study: comparative effectiveness of prophylactic ICD implantation

Aims

The clinical effectiveness of primary prevention implantable cardioverter defibrillator (ICD) therapy is under debate. The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators (EU‐CERT‐ICD) aims to assess its current clinical value.

Methods and results

The EU‐CERT‐ICD is a prospective investigator‐initiated non‐randomized, controlled, multicentre observational cohort study performed in 44 centres across 15 European Union countries. We will recruit 2250 patients with ischaemic or dilated cardiomyopathy and a guideline indication for primary prophylactic ICD implantation. This sample will include 1500 patients at their first ICD implantation and 750 patients who did not receive a primary prevention ICD despite having an indication for it (non‐randomized control group). The primary endpoint is all‐cause mortality; the co‐primary endpoint in ICD patients is time to first appropriate shock. Secondary endpoints include sudden cardiac death, first inappropriate shock, any ICD shock, arrhythmogenic syncope, revision procedures, quality of life, and cost‐effectiveness. At baseline (and prior to ICD implantation if applicable), all patients undergo 12‐lead electrocardiogram (ECG) and Holter ECG analysis using multiple advanced methods for risk stratification as well as detailed documentation of clinical characteristics and laboratory values. Genetic biobanking is also organized. As of August 2018, baseline data of 2265 patients are complete. All subjects will be followed for up to 4.5 years.

Conclusions

The EU‐CERT‐ICD study will provide a necessary update about clinical effectiveness of primary prophylactic ICD implantation. This study also aims for improved risk stratification and patient selection using clinical and ECG risk markers.

Sex differences in outcomes of primary prevention implantable cardioverter-defibrillator therapy: combined registry data from eleven European countries

Aims

Therapy with an implantable cardioverter defibrillator (ICD) is established for the prevention of sudden cardiac death (SCD) in high risk patients. We aimed to determine the effectiveness of primary prevention ICD therapy by analysing registry data from 14 centres in 11 European countries compiled between 2002 and 2014, with emphasis on outcomes in women who have been underrepresented in all trials.

Methods and results

Retrospective data of 14 local registries of primary prevention ICD implantations between 2002 and 2014 were compiled in a central database. Predefined primary outcome measures were overall mortality and first appropriate and first inappropriate shocks. A multivariable model enforcing a common hazard ratio for sex category across the centres, but allowing for centre-specific baseline hazards and centre specific effects of other covariates, was adjusted for age, the presence of ischaemic cardiomyopathy or a CRT-D, and left ventricular ejection fraction ≤25%. Of the 5033 patients, 957 (19%) were women. During a median follow-up of 33 months (IQR 16-55 months) 129 women (13%) and 807 men (20%) died (HR 0.65; 95% CI: [0.53, 0.79], P-value < 0.0001). An appropriate ICD shock occurred in 66 women (8%) and 514 men (14%; HR 0.61; 95% CI: 0.47-0.79; P = 0.0002).

Conclusion

Our retrospective analysis of 14 local registries in 11 European countries demonstrates that fewer women than men undergo ICD implantation for primary prevention. After multivariate adjustment, women have a significantly lower mortality and receive fewer appropriate ICD shocks.

Gender differences in the use of primary prevention ICDs in New Zealand patients with heart failure

Objective

Women have been under-represented in randomised clinical trials for primary prevention implantable cardioverter defibrillators (ICDs), and there are concerns about the efficacy of devices between genders. Our study aimed to investigate gender differences in the use of primary prevention ICD in patients with heart failure from the northern region of New Zealand.

Methods

Patients with heart failure with systolic dysfunction who received primary prevention ICD/cardiac resynchronisation therapy-defibrillator (CRT-D) in the northern region of New Zealand from 1 January 2007 to 1 June 2015 were included. Complications, mortality and hospitalisation events were reviewed.

Results

Of the 385 patients with heart failure implanted with ICD/CRT-D, women comprised 15.1% (n=58), and no change in utilisation of these devices was observed over the study period among women. Women were more likely to have non-ischaemic cardiomyopathy and have higher perioperative complications (8.6% vs 2.5%, P=0.02), with non-significant higher trend towards increased lead displacement (5.2% vs 1.8%, P=0.12). Women appeared to have lower all-cause (10.3% vs 18.7%, P=0.12), cardiovascular (5.2% vs 11.9%, P=0.13) and heart failure (3.5% vs 7.9%, P=0.22) mortalities but was not statistically significant. There were no gender differences in all-cause (70.7% vs 67%, P=0.58) or heart failure (19% vs 25%, P=0.32) readmissions.

Conclusion

Perioperative complications were significantly more common in women referred for ICD/CRT-D. Although there has been a significant increase in ICD implantation rates, gender differences in the use of these devices still exist in New Zealand, in keeping with the demographics of ischaemic heart disease and systolic dysfunction between genders.

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.

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.