Use of ICDs for Primary Prevention in Women and Men
Use of ICDs for Primary Prevention in Women and Men
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.
Recent clinical trials have expanded indications for implantable cardioverter defibrillators (ICDs) for the primary prevention of sudden cardiac death. However, many eligible patients do not receive this therapy, and previous studies have demonstrated that certain groups, specifically women, are less likely to be referred for primary prevention ICD therapy.
Existing evidence and guidelines do not support the differential use of ICD therapy according to gender. Although women constitute only approximately 20% of the patient population in the large primary prevention trials for ICD therapy, there is no evidence that the benefits of ICD therapy vary by gender. Current practice guidelines based on these trials recommend primary prevention ICD therapy in both women and men with severe left ventricular systolic dysfunction. Possible explanations for observed gender differences in ICD implantation rates include that fewer women may be truly eligible for ICD therapy, that a disproportionately smaller number of eligible women are referred for ICD therapy, or that the criteria used to select women for ICD implantation in practice are more stringent.
We sought to compare the extent to which women and men receiving ICD therapy in the United States conform to the criteria for patient selection based on major clinical trials. We hypothesized that, given prior evidence that women are less likely to be referred for primary prevention ICD therapy, women who actually undergo ICD implantation would be more likely to meet these criteria.
Abstract and Introduction
Abstract
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.
Introduction
Recent clinical trials have expanded indications for implantable cardioverter defibrillators (ICDs) for the primary prevention of sudden cardiac death. However, many eligible patients do not receive this therapy, and previous studies have demonstrated that certain groups, specifically women, are less likely to be referred for primary prevention ICD therapy.
Existing evidence and guidelines do not support the differential use of ICD therapy according to gender. Although women constitute only approximately 20% of the patient population in the large primary prevention trials for ICD therapy, there is no evidence that the benefits of ICD therapy vary by gender. Current practice guidelines based on these trials recommend primary prevention ICD therapy in both women and men with severe left ventricular systolic dysfunction. Possible explanations for observed gender differences in ICD implantation rates include that fewer women may be truly eligible for ICD therapy, that a disproportionately smaller number of eligible women are referred for ICD therapy, or that the criteria used to select women for ICD implantation in practice are more stringent.
We sought to compare the extent to which women and men receiving ICD therapy in the United States conform to the criteria for patient selection based on major clinical trials. We hypothesized that, given prior evidence that women are less likely to be referred for primary prevention ICD therapy, women who actually undergo ICD implantation would be more likely to meet these criteria.
