Sex-Specific Differences in Survival and Heart Failure Hospitalization After Cardiac Resynchronization Therapy With or Without Defibrillation

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

A disease of her own? Unique features of heart failure in women

Heart failure (HF) is a significant and growing public health challenge for women. Compared with men, women tend to develop HF later in life and are more likely to experience HF with preserved ejection fraction. There are also significant sex differences in outcomes, with women reporting lower quality of life but overall better survival versus men. In this review, we summarize sex differences in traditional HF risk factors, such as hypertension, diabetes, obesity and coronary artery disease, as well as female-specific HF risk factors including menopause, pregnancy and adverse pregnancy outcomes, and breast cancer therapy. While our understanding of the sex-specific efficacy of HF therapy remains limited by the underrepresentation of women in major clinical trials, there is a suggestion of preferential benefit of specific agents for women. Further work is required to better understand the pathophysiology of HF in women uniquely and to increase representation of women in clinical trials.

A long-term cost-effectiveness analysis of cardiac resynchronisation therapy with or without defibrillator based on health claims data

BACKGROUND

In Germany, CRT devices with defibrillator capability (CRT-D) have become the predominant treatment strategy for patients with heart failure and cardiac dyssynchrony. However, according to current guidelines, most patients would also be eligible for the less expensive CRT pacemaker (CRT-P). We conducted a cost-effectiveness analysis for CRT-P devices compared to CRT-D devices from a German payer's perspective.

METHODS

Longitudinal health claims data from 3569 patients with de novo CRT implantation from 2014 to 2019 were used to parametrise a cohort Markov model. Model outcomes were costs and effectiveness measured in terms of life years. Transition probabilities were derived from multivariable parametric survival regression that controlled for baseline differences of CRT-D and CRT-P patients. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

The Markov model predicted a median survival of 84 months for CRT-P patients and 92 months for CRT-D patients. In the base case, CRT-P devices incurred incremental costs of € - 13,093 per patient and 0.30 incremental life years were lost. The ICER was € 43,965 saved per life year lost. In the probabilistic sensitivity analysis, uncertainty regarding the effectiveness was observed but not regarding costs.

CONCLUSION

This modelling study illustrates the uncertainty of the higher effectiveness of CRT-D devices compared to CRT-P devices. Given the difference in incremental costs between CRT-P and CRT-D treatment, there would be significant potential cost savings to the healthcare system if CRT-D devices were restricted to patients likely to benefit from the additional defibrillator.

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.

OUP accepted manuscript

Aims

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure. There is contradictory evidence whether defibrillator capability improves prognosis in patients receiving CRT. We compared the survival of patients undergoing de novo implantation of a CRT with defibrillator (CRT-D) option and CRT with pacemaker (CRT-P) in a large health claims database.

Methods and results

Using health claims data of a major German statutory health insurance, we analysed patients with de novo CRT implantation from 2014 to 2019 without indication for defibrillator implantation for secondary prevention of sudden cardiac death. We performed age-adjusted Cox proportional hazard regression and entropy balancing to calculate weights to control for baseline imbalances. The analysis comprised 847 CRT-P and 2722 CRT-D patients. Overall, 714 deaths were recorded during a median follow-up of 2.35 years. A higher cumulative incidence of all-cause death was observed in the initial unadjusted Kaplan–Meier time-to-event analysis [hazard ratio (HR): 1.63, 95% confidence interval (CI): 1.38–1.92]. After adjustment for age, HR was 1.13 (95% CI: 0.95–1.35) and after entropy balancing 0.99 (95% CI: 0.81–1.20). No survival differences were found in different age groups. The results were robust in sensitivity analyses.

Conclusion

In a large health claims database of CRT implantations performed in a contemporary setting, CRT-P treatment was not associated with inferior survival compared with CRT-D. Age differences accounted for the greatest part of the survival difference that was observed in the initial unadjusted analysis.

Estimate and reporting of longevity for cardiac implantable electronic devices: a proposal for standardized criteria

BACKGROUND

Cardiac implantable electronic devices (CIEDs) are widely used according to consensus guidelines in various patient categories. The longevity of CIED is a major determinant of the frequency with which patients require device replacement. Given the mismatch between the useful life of the devices and patient survival, device replacement is often needed. There is a great variability in the criteria used by manufacturers to determine the longevity of pacemakers (PM), implantable defibrillators (ICDs), and devices for cardiac resynchronization therapy (CRT). Thus, a fair comparison and an effective device evaluation is often difficult.

METHODS

The objective of this paper is to provide standardized criteria based on typical clinical settings for estimating the longevity of single and dual chamber ICDs, cardiac resynchronization defibrillators (CRT-D), single and dual chamber PMs, and cardiac resynchronization PMs (CRT- P) to be used in health technology assessment for an appropriate comparison among different devices.

RESULTS

The proposed parameters, if applied to the current marketed devices, provide longevity values in the range 5-17.2 years.

CONCLUSION

The values of longevity with the non-standardized criteria used by the manufacturers result in higher maximum values respect to the proposed standardized criteria for CRT-D, CRTD-MPP, CRT-P, and Dual-chamber PM.

The benefits of defibrillator in heart failure patients with cardiac resynchronization therapy: A meta-analysis

BACKGROUND

Current guidelines did not provide recommendations on indications of an additional implantable cardioverter-defibrillator (ICD) to patients receiving cardiac resynchronization therapy (CRT), and it still remains controversial due to lack of evidence from randomized controlled trials.

METHOD

PubMed, Embase, and Cochrane CENTRAL from the inception to May 2020 were systematically screened for studies reporting on the comparison of cardiac resynchronization therapy with defibrillator (CRT-D) and cardiac resynchronization therapy with pacemaker (CRT-P), focusing on the adjusted hazard ratio (aHR) of all-cause mortality. We pooled the effects using a random-effect model.

RESULTS

Twenty-one studies encompassing 69,919 patients were included in this meta-analysis. With no restriction to characteristics of including population, CRT-D was associated with a lower all-cause mortality compared with CRT-P significantly (aHR: 0.80, 95% confidence interval [CI]: 0.74-0.87, I²  = 36.8%, p < .001). This mortality benefit was also observed in patients with ischemic cardiomyopathy (aHR: 0.74, 95% CI: 0.64-0.86, I²  = 0%, p < .001). However, there is no significant difference in patients with nonischemic cardiomyopathy (NICM) (aHR: 0.91, 95% CI: 0.82-1.01, I²  = 0%, p = .087), older age (age ≥75 years, aHR: 0.96, 95% CI: 0.83-1.12, I²  = 0%, p = .610). Subgroup analysis was performed and indicated the survival benefit of CRT-D for primary prevention compared with CRT-P (aHR: 0.87, 95% CI: 0.79-0.95, I²  = 0%, p = .003).

CONCLUSION

After adjusted the differences in clinical characteristics, additional ICD therapy was associated with a reduced all-cause mortality in patients receiving CRT. However, our work suggested that additional ICD may not be applied to elderly (≥75 years) or patients with NICM.

Sex-Specific Differences in Survival and Heart Failure Hospitalization After Cardiac Resynchronization Therapy With or Without Defibrillation

Background

Women are underrepresented in cardiac resynchronization therapy (CRT) trials. Some studies suggest that women fare better than men after CRT. We sought to explore clinical outcomes in women and men undergoing CRT‐defibrillation or CRT‐pacing in real‐world clinical practice.

Methods and Results

A national database (Hospital Episode Statistics for England) was used to quantify clinical outcomes in 43 730 patients (women: 10 890 [24.9%]; men: 32 840 [75.1%]) undergoing CRT over 7.6 years, (median follow‐up 2.2 years, interquartile range, 1–4 years). In analysis of the total population, the primary end point of total mortality (adjusted hazard ratio [aHR], 0.73; 95% CI, 0.69–0.76) and the secondary end point of total mortality or heart failure hospitalization (aHR, 0.79, 95% CI 0.75–0.82) were lower in women, independent of known confounders. Total mortality (aHR, 0.73; 95% CI, 0.70–0.76) and total mortality or heart failure hospitalization (aHR, 0.79; 95% CI, 0.75–0.82) were lower for CRT‐defibrillation than for CRT‐pacing. In analyses of patients with (aHR, 0.89; 95% CI, 0.80–0.98) or without (aHR, 0.70; 95% CI, 0.66–0.73) a myocardial infarction, women had a lower total mortality. In sex‐specific analyses, total mortality was lower after CRT‐defibrillation in women (aHR, 0.83; P=0.013) and men (aHR, 0.69; P<0.001).

Conclusions

Compared with men, women lived longer and were less likely to be hospitalized for heart failure after CRT. In both sexes, CRT‐defibrillation was superior to CRT‐pacing with respect to survival and heart failure hospitalization. The longest survival after CRT was observed in women without a history of myocardial infarction.