The impact of gender difference on clinical and echocardiographic outcomes in patients with heart failure after cardiac resynchronization therapy: A systematic review and meta-analysis

Heart size disparity drives sex-specific response to cardiac resynchronization therapy: a post-hoc analysis of the MORE-MPP CRT trial

Background

Studies have reported that female sex predicts superior cardiac resynchronization therapy (CRT) response. One theory is that this association is related to smaller female heart size, thus increased "relative dyssynchrony" at given QRS durations (QRSd).

Objective

To investigate the mechanisms of sex-specific CRT response relating to heart size, relative dyssynchrony, cardiomyopathy type, QRS morphology, and other patient characteristics.

Methods

A post-hoc analysis of the MORE-CRT MPP trial (n=3739, 28% female), with a sub-group analysis of patients with non-ischaemic cardiomyopathy (NICM) and left bundle branch block (LBBB) (n=1308, 41% female) to control for confounding characteristics. A multivariable analysis examined predictors of response to 6 months of conventional CRT, including sex and relative dyssynchrony, measured by QRSd/LVEDV (left ventricular end-diastolic volume).

Results

Females had a higher CRT response rate than males (70.1% vs. 56.8%, p<0.0001). Subgroup analysis: Regression analysis of the NICM LBBB subgroup identified QRSd/LVEDV, but not sex, as a modifier of CRT response (p<0.0039). QRSd/LVEDV was significantly higher in females (0.919) versus males (0.708, p<0.001). CRT response was 78% for female patients with QRSd/LVEDV>median value, compared to 68% < median value (p=0.012). Association between CRT response and QRSd/LVEDV was strongest at QRSd<150ms.

Conclusions

In the NICM LBBB population, increased relative dyssynchrony in females, who have smaller heart sizes than their male counterparts, is a driver of sex-specific CRT response, particularly at QRSd <150ms. Females may benefit from CRT at a QRSd <130ms, opening the debate on whether sex-specific QRSd cut-offs or QRS/LVEDV measurement should be incorporated into clinical guidelines.

Sudden Death in Men Versus Women with Heart Failure

PURPOSE OF REVIEW

Sudden cardiac death (SCD) represents the most feared complication of heart failure (HF). This review intends to provide insight on our current knowledge of sex differences in SCD mechanisms, prevention, and management in HF patients.

RECENT FINDINGS

Women with HF present a better prognosis than men and have a lower incidence of SCD, irrespective of the presence of ischemic heart disease and age. The influence of sex hormones, sex differences in intracellular calcium handling, and a differential myocardial remodeling may explain such a gap between men and women. Both HF drugs and ventricular arrhythmias ablation seems also useful for the management of women at risk of SCD, but special care must be taken with the use of antiarrhythmic QT-prolonging drugs. However, implantable cardioverter defibrillator (ICD) use has not been shown to be equally effective in women than men. Sex-specific recommendations regarding SCD in HF are still lacking due to the scarcity of information and the under-representation of women in clinical trials. Further investigation is required to provide specific risk stratification models in women. Cardiac magnetic resonance imaging, genetics development, and personalized medicine will probably play an increasing role in this evaluation.

Interamerican Society of Cardiology (CIFACAH - ELECTROSIAC)/Latin American Heart Rhythm Society (LAHRS): multidisciplinary review on the appropriate use of cardiac resynchronization therapy in heart failure

Epidemiological studies suggest that approximately half of the patients with heart failure (HF) have reduced ejection fraction, while the other half have normal ejection fraction (EF). Currently, international guidelines consider QRS duration greater than 130 ms, in the presence of ventricular dysfunction (EF < 35%), as a criterion for selecting patients for cardiac resynchronization therapy (CRT). CRT helps restore intraventricular and auriculoventricular synchrony, improving left ventricular (LV) performance, reducing functional mitral regurgitation, and inducing reverse LV remodeling. This is evidenced by increased LV filling time and left ventricular ejection fraction, decreased LV end-diastolic and end-systolic volumes, mitral regurgitation, and septal dyskinesia. Because the mechanisms of dyssynchrony may be heterogeneous, no single measure may accurately predict response to CRT. Finally, CRT has been progressively shown to be safe and feasible, improves functional status and quality of life, reversely remodels the LV, decreases the number of hospitalizations, total mortality in patients with refractory HF, LV dysfunction, and intraventricular conduction disorders; is a pacemaker-based therapy for HF and thanks to current technology, safe remote monitoring of almost all types of cardiac devices is possible and provides useful alerts in clinical practice.

Neuromodulation devices for heart failure

Autonomic imbalance with a sympathetic dominance is acknowledged to be a critical determinant of the pathophysiology of chronic heart failure with reduced ejection fraction (HFrEF), regardless of the etiology. Consequently, therapeutic interventions directly targeting the cardiac autonomic nervous system, generally referred to as neuromodulation strategies, have gained increasing interest and have been intensively studied at both the pre-clinical level and the clinical level. This review will focus on device-based neuromodulation in the setting of HFrEF. It will first provide some general principles about electrical neuromodulation and discuss specifically the complex issue of dose-response with this therapeutic approach. The paper will thereafter summarize the rationale, the pre-clinical and the clinical data, as well as the future prospectives of the three most studied form of device-based neuromodulation in HFrEF. These include cervical vagal nerve stimulation (cVNS), baroreflex activation therapy (BAT), and spinal cord stimulation (SCS). BAT has been approved by the Food and Drug Administration for use in patients with HfrEF, while the other two approaches are still considered investigational; VNS is currently being investigated in a large phase III Study.

Predictors of echocardiographic response to cardiac resynchronization therapy: A systematic review with Meta-Analysis

•

NYHA class II seems to predict response to CRT.

•

We should not delay CRT, trying medical management first, even in mildly symptomatic patients.

•

Atrial fibrillation patients must have the same indication for CRT as those in sinus rhythm.

Background

At least 30% of the patients do not respond to cardiac resynchronization therapy (CRT). We performed a systematic review and meta-analysis of real-world studies trying to identify predictors of response to CRT.

Methods

PubMed, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for observational prospective studies, referring the evaluation of response to CRT, defined as a decrease in left ventricle end-systolic volume (LVESV) ≥ 15% at 6-month follow-up, via two-dimensional echocardiography.

Results

A total of 24 studies were included. The meta-analysis showed that female gender (p = 0.018), non-ischemic cardiomyopathy (NICM) (p < 0.001), left bundle branch morphology (LBBB) (p = 0.001), longer QRS (p < 0.001) and New York Heart Association (NYHA) class II (p = 0.014) appear to favor response to CRT. After ROC analysis and logistic regression procedures, female gender (kappa = 0.450; p < 0.001), NICM (kappa = 0.636; p < 0.001), LBBB (kappa = 0.935; p < 0.001), and NYHA class II (kappa = 0.647; p < 0.001) were identified as independent predictors of response to CRT, being LBBB the most reliable one (sensitivity = 97.24%; specificity = 98.86%).

Conclusions

Female gender, NICM, LBBB and NYHA class II are baseline variables with an apparent capability to independently predict response to CRT, being LBBB the most reliable one.

Sex, Race, and Age Differences of Cardiovascular Outcomes in Cardiac Resynchronization Therapy RCTs: A Systematic Review and Meta-analysis

Background

Cardiac resynchronization therapy (CRT) is beneficial in patients who have heart failure with reduced ejection fraction or arrhythmic events. However, most randomized controlled trials (RCTs) showing survival benefits primarily enrolled older white men. This study aims to evaluate CRT efficacy by sex, race, and age in RCTs.

Methods

Five electronic databases (CINAHL, Embase, Emcare, Medline, and PubMed) were searched from inception to July 12, 2021 for RCTs with CRT in adult patients. Data were analyzed for clinical outcomes including all-cause or cardiovascular (CV) death, worsening heart failure (HF), and HF hospitalization (HFH) according to sex, race, and age.

Results

Among six RCTs with up to moderate risk of bias, 54% (n = 3,630 of 6,682; mean age 64 years, 22% female, 8% black patients) had CRT device implantation. All-cause death (odds ratio [OR], 0.51; P = 0.053) was reduced in female versus male CRT patients, whereas CV death, HFH, or all-cause death with worsening HF or HFH did not differ significantly. No difference was seen in CRT patients for all-cause death and worsening HF (OR, 1.32; P = 0.46) among white vs black patients or for all-cause death and HFH (OR, 1.19; P = 0.55) among ≥ 65 versus < 65 years.

Conclusions

Whereas all-cause death was lower in female CRT patients, other reported outcomes did not significantly differ by sex, race, or age. Only 6 studies partially reported outcomes. Thus, enhanced reporting and analyses are required to overcome such paucity of data to evaluate the impact of these factors on clinical outcomes in distinct patient cohorts with CRT indication.

Sex Differences in Implantation and Outcomes of Cardiac Resynchronization Therapy in Real-World Settings: A Systematic Review of Cohort Studies

Background

Evidence from randomized trials is conflicting on the effects of cardiac resynchronization therapy (CRT) by sex, and differences in access are unknown. We examined sex differences in the implantation rates and outcomes in patients treated with CRT using cohort studies.

Methods

We followed a pre-specified protocol (International Prospective Register of Systematic Reviews [PROSPERO]: CRD42020204804). MEDLINE, Embase, and Web of Science were searched for cohort studies from January 2000 to June 2020 that evaluated the response to CRT in patients ≥ 18 years old and reported sex-specific information in any language.

Results

We included 97 studies (1,172,654 men and 486,553 women). Men received CRT more frequently than women (median ratio, 3.16; 25th to 75th interquartile range, 2.48-3.62). In the unadjusted analysis, men had a greater long-term all-cause mortality rate after CRT, compared with women (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.38-1.63; P < 0.001). Adjustment for confounders did not affect the strength or direction of association (HR, 1.45; 95% CI, 1.32-1.59; P < 0.001). Women achieved a greater rate of improvement in left ejection fraction compared with men (HR, 4.66; 95% CI, 4.23-5.13; P < 0.001). Men had a lower risk of a pneumothorax (relative risk, 0.21; 95% CI, 0.13-0.34; P < 0.001]); otherwise, there were no differences in complications.

Conclusions

We found in this large meta-analysis that men were more often implanted with CRT than women, yet men had a higher long-term all-cause mortality following CRT, compared with women, and smaller improvement in left ventricular ejection fraction. Reasons for this difference in implantation rates of CRT in real-world practice need to be investigated.

Sex Differences in Heart Failure

Heart failure (HF) continues to be a major contributor of morbidity and mortality for men and women alike, yet how the predisposition for, course and management of HF differ between men and women remains underexplored. Sex differences in traditional risk factors as well as sex-specific risk factors influence the prevalence and manifestation of HF in unique ways. The pathophysiology of HF differs between men and women and may explain sex-specific differences in clinical presentation and diagnosis. This in turn contributes to variation in response to both pharmacologic and device/surgical therapy. This review examines sex-specific differences in HF spanning prevalence, risk factors, pathophysiology, presentation, and therapies with a specific focus on highlighting gaps in knowledge with calls to action for future research efforts.

Response by Sex in Patient-Centered Outcomes With Baroreflex Activation Therapy in Systolic Heart Failure

OBJECTIVES

The aim of this study was to assess sex differences in the efficacy and safety of baroreflex activation therapy (BAT) in the BeAT-HF (Baroreflex Activation Therapy for Heart Failure) trial.

BACKGROUND

Patients were randomized 1:1 to receive guideline-directed medical therapy (GDMT) alone (control group) or BAT plus GDMT.

METHODS

Pre-specified subgroup analyses including change from baseline to 6 months in 6-min walk distance (6MWD), quality of life (QoL) assessed using the Minnesota Living With Heart Failure Questionnaire (MLWHQ), New York Heart Association (NYHA) functional class, and N-terminal pro–B-type natriuretic peptide (NT-proBNP) were conducted in men versus women.

RESULTS

Fifty-three women and 211 men were evaluated. Women had similar baseline NT-proBNP levels, 6MWDs, and percentage of subjects with NYHA functional class III symptoms but poorer MLWHQ scores (mean 62 ± 22 vs. 50 ± 24; p = 0.01) compared with men. Women experienced significant improvement from baseline to 6 months with BAT plus GDMT relative to GDMT alone in MLWHQ score (—34 ± 27 vs. —9 ± 23, respectively; p < 0.01), 6MWD (44 ± 45 m vs. —32 118 m; p < 0.01), and improvement in NYHA functional class (70% vs. 27%; p < 0.01), similar to the responses seen in men, with no significant difference in safety. Women receiving BAT plus GDMT had a significant decrease in NT-proBNP (—43% vs. 7% with GDMT alone; difference —48%; p < 0.01), while in men this decrease was —15% versus 2%, respectively (difference —17%; p = 0.08), with an interaction p value of 0.05.

CONCLUSIONS

Women in BeAT-HF had poorer baseline QoL than men but demonstrated similar improvements with BAT in 6MWD, QoL, and NYHA functional class. Women had a significant improvement in NT-proBNP, whereas men did not. (Baroreflex Activation Therapy for Heart Failure [BeAT-HF]; NCT02627196) (J Am Coll Cardiol HF 2021;9:430–8)

Sex differences in acute cardiovascular care: a review and needs assessment

Despite significant progress in the care of patients suffering from cardiovascular disease, there remains a persistent sex disparity in the diagnosis, management, and outcomes of these patients. These sex disparities are seen across the spectrum of cardiovascular care, but, are especially pronounced in acute cardiovascular care. The spectrum of acute cardiovascular care encompasses critically ill or tenuous patients with cardiovascular conditions that require urgent or emergent decision-making and interventions. In this narrative review, the disparities in the clinical course, management, and outcomes of six commonly encountered acute cardiovascular conditions, some with a known sex-predilection will be discussed within the basis of underlying sex differences in physiology, anatomy, and pharmacology with the goal of identifying areas where improvement in clinical approaches are needed.

Sex-Specific Patterns of Mortality Predictors Among Patients Undergoing Cardiac Resynchronization Therapy: A Machine Learning Approach

Background: The relative importance of variables explaining sex-related differences in outcomes is scarcely explored in patients undergoing cardiac resynchronization therapy (CRT). We sought to implement and evaluate machine learning (ML) algorithms for the prediction of 1- and 3-year all-cause mortality in CRT patients. We also aimed to assess the sex-specific differences in predictors of mortality utilizing ML. Methods: Using a retrospective registry of 2,191 CRT patients, ML models were implemented in 6 partially overlapping patient subsets (all patients, females, or males with 1- or 3-year follow-up). Each cohort was randomly split into training (80%) and test sets (20%). After hyperparameter tuning in the training sets, the best performing algorithm was evaluated in the test sets. Model discrimination was quantified using the area under the receiver-operating characteristic curves (AUC). The most important predictors were identified using the permutation feature importances method. Results: Conditional inference random forest exhibited the best performance with AUCs of 0.728 (0.645-0.802) and 0.732 (0.681-0.784) for the prediction of 1- and 3-year mortality, respectively. Etiology of heart failure, NYHA class, left ventricular ejection fraction, and QRS morphology had higher predictive power, whereas hemoglobin was less important in females compared to males. The importance of atrial fibrillation and age increased, while the importance of serum creatinine decreased from 1- to 3-year follow-up in both sexes. Conclusions: Using ML techniques in combination with easily obtainable clinical features, our models effectively predicted 1- and 3-year all-cause mortality in CRT patients. Sex-specific patterns of predictors were identified, showing a dynamic variation over time.

Sex-Specific Ventricular Arrhythmias and Mortality in Cardiac Resynchronization Therapy Recipients

OBJECTIVES

The study goal was to examine whether there are sex-related differences in the incidence of ventricular arrhythmias and mortality in CRT-defibrillator (CRT-D) recipients.

BACKGROUND

Few studies have evaluated sex-related benefits of cardiac resynchronization therapy (CRT). Moreover, data on sex-related differences in the occurrence of ventricular tachyarrhythmias in this population are limited.

METHODS

A multicenter retrospective study was conducted in 460 patients (355 male subjects and 105 female subjects) from the UMBRELLA (Incidence of Arrhythmia in Spanish Population With a Medtronic Implantable Cardiac Defibrillator Implant) national registry. Patients were followed up through remote monitoring after the first implantation of a CRT-D during a median follow-up of 2.2 ± 1.0 years. Sex differences were analyzed in terms of ventricular arrhythmia-treated incidence and death during the follow-up period, with a particular focus on primary prevention patients.

RESULTS

Baseline New York Heart Association functional class was worse in women compared with that in men (67.0% of women in New York Heart Association functional class III vs. 49.7% of men; p = 0.003), whereas women had less ischemic cardiac disease (20.8% vs. 41.7%; p < 0.001). Female sex was an independent predictor of ventricular arrhythmias (hazard ratio: 0.40; 95% confidence interval: 0.19 to 0.86; p = 0.020), as well as left ventricular ejection fraction and nonischemic cardiomyopathy. Mortality in women was one-half that of men, although events were scarce and without significant differences (2.9% vs. 5.6%; p = 0.25).

CONCLUSIONS

Women with left bundle branch block and implanted CRT have a lower rate of ventricular tachyarrhythmias than men. All-cause mortality in patients is, at least, similar between female and male subjects.

Performance of Prognostic Risk Scores in Heart Failure Patients: Do Sex Differences Exist?

BACKGROUND

Sex differences in the performance of prognostic risk scores in heart failure (HF) patients have not previously been investigated. We examined the performance of 2 commonly used scores in predicting mortality and a composite end point consisting of ventricular assist device, heart transplantation, or mortality in women vs men with HF.

METHODS

This was a retrospective study of 1,136 (25% women) consecutive ambulatory adult HF patients with reduced left ventricular ejection fraction (≤ 40%) followed at a single institution from 2000 to 2012. Discrimination, calibration, and absolute risk reclassification of the Seattle Heart Failure Model (SHFM) and the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score to predict 1- and 3-year outcomes were compared between women and men.

RESULTS

At 1- and 3-year follow-ups, 116 (22% women) and 231 (21% women) patients died, respectively. Survival was equal between sexes (P = 0.41). The SHFM and the MAGGIC score showed similar discriminatory capacity in women (c-statistics 0.84, 95% CI 0.77-0.92, and 0.74, 95% CI 0.64-0.83) and men (c-statistics 0.74, 95% CI 0.69-0.79, and 0.70, 95% CI 0.64-0.75). There was no difference in the predicted and observed 1-year mortality by the scores in both sexes. Compared with the SHFM, the MAGGIC score better reclassified 10% (95% CI 7%-14%) of women and 18% (95% CI 15%-20%) of men. At 3-year follow-up, similar results were seen for discrimination, whereas both scores overestimated mortality with more marked overestimation in women. The results were reproducible for the composite end point, with improved calibration at 3-year follow-up in both scores.

CONCLUSIONS

Our findings support the use of the MAGGIC score in both women and men owing to better risk classification.

[Cardiac implantable electronic devices and health-related quality of life]

Patients, scientists and healthcare providers are increasingly interested in identifying interventions that not only reduce mortality but also improve symptoms, function and health-related quality of life. Health-related quality of life is a strong, independent predictor of mortality, cardiovascular events, hospitalization and treatment costs in patients with cardiac diseases. Remote monitoring of pacemakers has a positive effect on health-related quality of life and functional capacity and is equivalent to monitoring these patients in hospitals. Implantation of an implantable cardioverter defibrillator has a major impact on mental health, with the majority of patients experiencing the fear of ICD shocks as particularly detrimental to the quality of life. Variables, such as age, gender and duration of implantation should be considered in the assessment and planning of strategies for improving the quality of life of patients with electronic implantable cardiac devices.

Gender-Based Differences in Cardiac Resynchronization Therapy Response

Cardiac resynchronization therapy (CRT) has been shown to have a multitude of beneficial effects in select patients with systolic heart failure, by enhancing reverse remodeling, improving quality of life and functional status, reducing risk of heart failure admission, and most importantly, improving survival. Although women were underrepresented in the clinical trials, they were demonstrated to derive greater therapeutic benefit from CRT compared with men. Importantly, women were noted to derive benefit at a lesser degree of QRS prolongation than men, well below the now generally accepted cutoff of QRS ≥150 milliseconds.

Implantable Cardioverter-Defibrillators and Cardiac Resynchronization Therapy in Women

Implantable cardioverter-defibrillator and cardiac resynchronization therapy devices have been prescribed for patients with heart failure for several decades. Factors leading to increased usage include significant enhancements in technology and availability of multiple randomized clinical trials demonstrating their benefit with improved implementation of evidence-based guidelines. Despite these advances, gaps still exist in the utilization and referral of these devices, particularly among women. This article reviews the literature on these devices with a focus on gender differences and proposes reasons for why they exist.