A better survival for women with heart failure? It's not so simple

Representation of women in heart failure clinical trials: Barriers to enrollment and strategies to close the gap

Heart failure is a significant public health burden that differentially impacts women. Important sex- and gender-based differences in HF risk factors, presentation, and treatment exist, and the generation of high-quality evidence is critical to elucidate these differences. Despite the remarkable growth of the heart failure clinical research enterprise over the last four decades, women remain underrepresented in heart failure clinical trials relative to the population prevalence of heart failure in women. This disparity has resulted in significant knowledge gaps regarding the optimal care of women with heart failure. In this review, we summarize the existing literature regarding the participation of women in heart failure clinical trials. Additionally, we explain the evidence surrounding sex- and gender-specific barriers to enrollment in heart failure clinical trials and describe interventions that should be implemented throughout the clinical trial lifespan to achieve sex and gender parity.

Gender differences in Egyptian patients hospitalized with heart failure: insights from the European Society of Cardiology Heart Failure Long-Term Registry

Aims

This analysis evaluates gender differences in the Egyptian cohort of patients hospitalized for acute heart failure (AHF) in the European Society of Cardiology Heart Failure Long‐Term Registry.

Methods and results

From April 2011 to September 2014, 1634 patients hospitalized with AHF were enrolled by 20 hospitals all over Egypt. Of these patients, 1112 (68%) patients were male and 522 (32%) were female. Women presented with a higher admission systolic blood pressure and resting heart rate. Compared with men, women had a higher body mass index (32.5 ± 9.0 vs. 29.3 ± 4.9, P < 0.001), more frequent atrial fibrillation (34.7% vs. 22.4%, P < 0.001), and anaemia defined by haemoglobin < 12 g/dL (83.1% vs. 58.4%, P < 0.001). Women were more likely to present with heart failure with preserved ejection fraction (29.7% vs. 10.6%, P < 0.001). Women had more frequent diabetes mellitus (48.1% vs. 41.6%, P < 0.05) and hypertension (48.7% vs. 39.3%, P < 0.001) than had men, whereas smoking was rare among them (8.8% vs. 82.9%, P < 0.005). There was no significant difference in the primary aetiology of heart failure between both sexes. ACE inhibitors, beta‐blockers, mineralocorticoid receptor antagonists, antiplatelets, statins, and nitrates were less frequently prescribed to women, whereas they more often received digoxin, amiodarone, anticoagulants, and calcium channel blockers. There was no significant difference in in‐hospital (5.7% vs. 4.6%, P = 0.39) and 1 year mortality (27.9% vs. 25.9%, P = 0.48) between women and men, respectively.

Conclusions

Men and women with AHF differ significantly in baseline clinical characteristics and management but not in adverse outcomes. These findings emphasize the importance of individualized management and need for more comprehensive recruitment of women in clinical trials.

Heart failure in women

Heart failure (HF) has steadily increased in prevalence and affects both males and females equally. Despite this, there has been a significant underrepresentation of women in large scale HF trials. This disparity has lead to a deficit in understanding important gender-based differences in pathophysiology, diagnosis and treatment strategies. We review these gaps and explore a biological basis for varying outcomes. Endogenous estrogen plays an important role in epidemiology and outcome. The administration of exogenous estrogen has had varied success in treatment and is outlined extensively below. Additionally, we highlight unique HF syndromes through pregnancy and important sex-specific issues concerning transplant and mechanical circulatory support. A central theme remains: there is a clear need for increased female recruitment in clinical trials, and more studies exploring the role of gender-based biology in HF treatment.

Influence of gender on long-term prognosis of patients with chronic heart failure seen in heart failure clinics

BACKGROUND

Controversy exists concerning the influence of gender in the prognosis of patients with heart failure and no evidence is available from specific heart failure clinics.

HYPOTHESIS

Women with ambulatory heart failure are managed differently than men, although their prognosis might be better than men.

METHODS AND RESULTS

We analyzed the clinical characteristics, complementary test results, treatment, and prognosis in 4720 patients with chronic heart failure seen in 62 specialized clinics forming part of a multicenter registry during a mean follow-up of 40 months. The mean age was 65 +/- 12 years and 71% were men. The men were younger than the women and more often had a history of hyperlipidemia and ischemic heart disease. The men had a more advanced heart failure New York Heart Association (NYHA) functional class (III-IV) than the women and a greater frequency of systolic ventricular dysfunction. The men more often received treatment with beta-blockers, vasodilators, and antiplatelet aggregators as well as higher mean doses as compared with the women. The overall survival after the follow-up was similar for both genders, although the women had lower rates of survival free of admission for heart failure.

CONCLUSIONS

Despite the mortality of women and men with heart failure being similar, the rate of readmission for heart failure is greater in women in specialized heart failure clinics. These results may be associated with the pharmacological treatment differences observed.

Gender-related dissociation in outcomes in chronic heart failure: reduced mortality but similar hospitalization in women

BACKGROUND

The impact of gender on major natural history endpoints in heart failure (HF) has not been examined in a propensity-matched study.

METHODS

Of the 7788 chronic systolic and diastolic HF patients in the Digitalis Investigation Group trial 1926 were women. Propensity scores for female gender were used to assemble a cohort of 1669 pairs of men and women who were well-balanced on 32 measured baseline characteristics. Matched hazard ratios (HR) and 95% confidence intervals (CI) for outcomes associated with female gender were calculated using stratified Cox regression models.

RESULTS

All-cause mortality occurred in 36% (rate, 1256/10,000 person-years) and 30% (rate, 1008/10,000 person-years) of matched men and women respectively during 5 years of follow up (HR when women were compared with men, 0.82, 95% CI, 0.72-0.94, P=0.004). Female gender was also associated with reduced cardiovascular mortality (matched HR, 0.85; 95% CI, 0.73-0.99, P=0.037) and a trend toward reduced non-cardiovascular mortality (matched HR, 0.73; 95% CI, 0.53-1.00; P=0.053). All-cause hospitalization occurred in 67% (rate, 4003/10,000 person-years) and 65% (rate, 3762/10,000 person-years) matched male and female patients respectively (HR for women, 1.03, 95% CI, 0.93-1.15, P=0.538). Female gender was not associated with cardiovascular or HF hospitalization but was associated with hospitalization due to unstable angina pectoris (matched HR, 1.38; 95%CI, 1.11-1.72; P=0.003) and stroke (matched HR, 0.65; 95%CI, 0.46-0.92; P=0.014).

CONCLUSIONS

In patients with chronic HF, female gender has a significant independent association with improved survival but has no association with all-cause, cardiovascular, or HF hospitalizations.

Baseline differences in the HF-ACTION trial by sex

BACKGROUND

In patients with heart failure (HF), assessment of functional capacity plays an important prognostic role. Both 6-minute walk and cardiopulmonary exercise testing have been used to determine physical function and to determine prognosis and even listing for transplantation. However, as in HF trials, the number of women reported has been small, and the cutoffs for transplantation have been representative of male populations and extrapolated to women. It is also well known that peak VO(2) as a determinant of fitness is inherently lower in women than in men and potentially much lower in the presence of HF. Values for a female population from which to draw for this important determination are lacking.

METHODS

The HF-ACTION trial randomized 2,331 patients (28% women) with New York Heart Association class II-IV HF due to systolic dysfunction to either a formal exercise program in addition to optimal medical therapy or to optimal medical therapy alone without any formal exercise training. To characterize differences between men and women in the interpretation of final cardiopulmonary exercise testing models, the interaction of individual covariates with sex was investigated in the models of (1) VE/VCO(2), (2) VO(2) at ventilatory threshold (VT), (3) distance on the 6-minute walk, and (4) peak VO(2).

RESULTS

The women were younger than the men and more likely to have a nonischemic etiology and a higher ejection fraction. Dose of angiotensin converting enzyme inhibitor (ACEI) was lower in the women, on average. The lower ACEI dose may reflect the higher use of angiotensin II receptor blocker (ARB) in women. Both the peak VO(2) and the 6-minute walk distance were significantly lower in the women than in the men. Perhaps the most significant finding in this dataset of baseline characteristics is that the peak VO(2) for women was significantly lower than that for men with similar ventricular function and health status.

CONCLUSION

Therefore, in a well-medicated, stable, class II-IV HF cohort of patients who are able to exercise, women have statistically significantly lower peak VO(2) and 6-minute walk distance than men with similar health status and ventricular function. These data should prompt careful thought when considering prognostic markers for women and listing for cardiac transplant.

Sex Differences in Clinical Characteristics and Prognosis in a Broad Spectrum of Patients With Heart Failure

Background— We wished to test previous hypotheses that sex-related differences in mortality and morbidity may be due to differences in the cause of heart failure or in left ventricular ejection fraction (LVEF) by comparing fatal and nonfatal outcomes in women and men with heart failure and a broad spectrum of left ventricular ejection fraction.

Methods and Results— We compared outcomes in 2400 women and 5199 men randomized in the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity (CHARM) program using multivariable regression analyses. A total of 1188 women (50%) had a low LVEF (≤0.40), and 1212 had a preserved LVEF (>0.40). Among the men, 3388 (65%) had a low LVEF, and 1811 had a preserved LVEF. A total of 1216 women (51%) and 3465 men (67%) had an ischemic cause of their heart failure. All-cause mortality was 21.5% in women and 25.3% in men (adjusted hazard ratio [HR], 0.77; 95% CI, 0.69 to 0.86; P <0.001). Fewer women (30.4%) than men (33.3%) experienced cardiovascular death or heart failure hospitalization (adjusted HR, 0.83; 95% CI, 0.76 to 0.91; P <0.001). The risks of sudden death (HR, 0.70; 95% CI, 0.58 to 0.85) and death due to worsening heart failure (HR, 0.72; 95% CI, 0.58 to 0.89) were reduced to a comparable extent. The adjusted risk of cardiovascular hospitalization was also lower in women (HR, 0.88; 95% CI, 0.82 to 0.95), mainly because of a reduced risk of heart failure hospitalization (HR, 0.87; 95% CI, 0.78 to 0.97). Women had a lower risk of death irrespective of cause of heart failure or LVEF.

Conclusions— Among patients with heart failure, women have lower risks of most fatal and nonfatal outcomes that are not explained, as previously suggested, by LVEF or origin of the heart failure.