Is there a sex bias in implantable cardioverter-defibrillator referral and prescription?

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.

Failure to reassess ejection fraction after acute myocardial infarction in potential implantable cardioverter/defibrillator candidates: insights from the Translational Research Investigating Underlying disparities in acute Myocardial infarction Patients' Health Status (TRIUMPH) registry

BACKGROUND

Current practice guidelines advocate delaying assessment of primary prevention implantable cardioverter/defibrillator (ICD) candidacy at least 40 days after an acute myocardial infarction (AMI) because early ICD implantation after AMI has not demonstrated survival benefit. The rate at which interval reassessment of left ventricular ejection fraction (LVEF) occurs in potential primary prevention ICD candidates is unknown.

METHODS

We examined patients with AMI in the TRIUMPH registry with inhospital LVEF <40% discharged alive after their index presentation, excluding patients with a prior ICD and those who declined ICD during the index admission or were discharged to hospice. We conducted multivariable Poisson modeling to identify independent factors associated with LVEF reassessment by 6 months after AMI.

RESULTS

Of the 533 patients meeting the inclusion criteria, only 187 (35.1%) reported LVEF reassessment in the first 6 months after AMI and only 13 patients (2.4%) underwent ICD implantation by 1 year. In multivariable analysis, early cardiology follow-up after AMI was associated with a higher likelihood of LVEF reassessment (odds ratio 1.16, 95% confidence interval 1.06-1.28), whereas uninsured status and cardiologist-driving inpatient medical decision making were associated with a lower likelihood of LVEF reassessment (odds ratios 0.84 [95% CI 0.74-0.96] and 0.78 [95% CI 0.68-0.91], respectively).

CONCLUSIONS

In contemporary practice, almost 2 of 3 potential primary prevention ICD candidates did not report follow-up LVEF evaluation, with a very low rate of ICD implantation at 1 year. These results suggest an important gap in quality, highlighting the need for better transitions of care.

Epidemiology of adult congenital heart disease: demographic variations worldwide

The population of adults with a congenital heart defect (CHD) is increasing, due to improved survival after cardiac surgery. To accommodate the specialised care for these patients, a profound interest in the epidemiology of CHD is required. The exact size of the current population of adults with CHD is unknown, but the best available evidence suggests that currently overall prevalence of CHD in the adult population is about 3000 per million. Regional differences in CHD prevalence have been described, due to both variations in incidence and in mortality. Knowledge of demographic variations of CHD may lead to new aetiological insights and may be useful for preventive therapies. Socioeconomic status, education, urbanisation, climatological factors, ethnicity and patient-related factors, such as comorbidity, lifestyle and healthcare-seeking behaviour, may play a role in CHD incidence and mortality. The higher risk of several major cardiac outcomes in males with CHD might well explain at least partly the increased mortality rate in men. Regional differences in quality of life among CHD patients have been reported and although methodological differences may play a role, sociocultural differences warrant further attention. Socioeconomic outcomes in CHD patients, such as lower education, more unemployment and less relationships, might have a different impact on quality of life in different cultures. To gain more insight into demographic differences around the world large international multicentre studies on the epidemiology of CHD are needed.

Use of implantable cardioverter defibrillators for primary prevention in the community: do women and men equally meet trial enrollment criteria?

BACKGROUND

Fewer women than men undergo implantable cardioverter defibrillator (ICD) implantation for the primary prevention of sudden cardiac death. The criteria used to select patients for ICD implantation may be more permissive among men than for women. We hypothesized that women who undergo primary prevention ICD implantation more often meet strict trial enrollment criteria for this therapy.

METHODS

We studied 59,812 patients in the National Cardiovascular Data Registry ICD registry undergoing initial primary prevention ICD placement between January 2005 and April 2007. Patients were classified as meeting or not meeting enrollment criteria of either the MADIT-II or SCD-HeFT trials. Multivariable analyses assessed the association between gender and concordance with trial criteria adjusting for demographic, clinical, and system characteristics.

RESULTS

Among the cohort, 27% (n = 16,072) were women. Overall, 85.2% of women and 84.5% of men met enrollment criteria of either trial (P = .05). In multivariable analyses, women were equally likely to meet trial criteria (OR 1.04, 95% CI 0.99-1.10) than men. Significantly more women than men met the trial enrollment criteria among patients older than age 65 (86.6% of women vs 85.3% of men, OR 1.11, 95% CI 1.03-1.19), but this difference was not found among younger patients (82.5% of women vs 83.0% of men, OR 0.97, 95% CI 0.89-1.07).

CONCLUSIONS

In a national cohort undergoing primary prevention ICD implantation, older women were only slightly more likely then men to meet the enrollment criteria for MADIT II or SCD-HeFT. Relative overutilization in men is not an important explanation for gender differences in ICD implantation.

Gender and Outcome in Adult Congenital Heart Disease

Background— Gender differences in prognosis have frequently been reported in cardiovascular disease but less so in congenital heart disease. We investigated whether gender is associated with outcome in adult patients with congenital heart disease.

Methods and Results— From the CONgenital CORvitia (CONCOR) national registry for adults with congenital heart disease, 7414 patients were identified. All outcomes before entry into the registry and during subsequent follow-up were recorded, and differences between men and women were analyzed with the underlying congenital heart defect taken into account. Median age at the end of follow-up was 35 years (range, 17 to 91 years); 49.8% were female. No gender difference in mortality was found. Women had a 33% higher risk of pulmonary hypertension (odds ratio [OR]=1.33; 95% CI, 1.07 to 1.65; P =0.01), a 33% lower risk of aortic outcomes (OR=0.67; 95% CI, 0.50 to 0.90; P =0.007), a 47% lower risk of endocarditis (OR=0.53; 95% CI, 0.40 to 0.70; P <0.001), and a 55% lower risk of an implantable cardioverter-defibrillator (OR=0.45; 95% CI, 0.26 to 0.80; P =0.006). Furthermore, the risk of arrhythmias appeared to be lower in women (OR=0.88; 95% CI, 0.77 to 1.02; P =0.08).

Conclusions— The risk of several major cardiac outcomes in adult patients with congenital heart disease appears to vary by gender.

Influence of gender on ICD implantation for primary and secondary prevention of sudden cardiac death

AIMS

This study sought to investigate the influence of gender on access to ICD therapy and examine the influence of gender on subsequent ICD shock experience.

METHODS AND RESULTS

The records of 353 consecutive patients (140 and 213 secondary prevention, respectively) who received their first ICD between January 2000 and March 2004 were reviewed. All patients fulfilled criteria for primary or secondary prevention ICD implantation. Baseline characteristics and ICD shock experiences were compared. Female patients were younger and less likely to have a history of ischaemic heart disease or atrial arrhythmias (P<0.01). In contrast, female patients were more likely to have heart failure and diabetes (P<0.01). Markedly fewer females received an ICD for either primary (M:F ratio 8.5:1, P<0.01) or secondary (M:F ratio 4.5:1, P<0.01) prevention. Further, significantly fewer female patients received an ICD for MADIT II indications (M:F 11.2:1, P<0.01). Over the mean follow-up of 1.8+/-1.1 years, gender had no influence upon the likelihood of receiving either an appropriate or an inappropriate shock (P=ns).

CONCLUSION

Although male patients accounted for the great majority (85%) of all ICD recipients, there was no evidence of influence of gender on the likelihood of receiving an appropriate or inappropriate shock.