Author Disclosure Sex Differences in the Characteristics of Patients Receiving ICD Therapy for the Primary Prevention of Sudden Cardiac Death –Stacie L. Daugherty MD, MSPH - None –Pamela N. Peterson MD, MSPH - None –Yongfei Wang MS - None –Jeptha P. Curtis MD - None –Paul A. Heidenreich MD - None –Harlan M. Krumholz MD, SM - None –Humberto J. Vidaillet MD - None –Frederick A. Masoudi MD, MSPH – None –On behalf of the NCDR

Sex Differences in the Characteristics of Patients Receiving ICD Therapy for the Primary Prevention of Sudden Cardiac Death Stacie Luther Daugherty, MD, MSPH Assistant Professor of Medicine, Cardiology Division University of Colorado at Denver Health Sciences Center

Background Studies suggest fewer women receive ICD therapy for 1º prevention Reasons for sex difference unknown –Fewer eligible women –Fewer eligible women referred –Differences in application of trial criteria: overuse in men? Davis DR, Europace 2006;8:1054; Gauri AJ, Am J Med 2006;119:167.e17; Curtis LH, JAMA 2007;298(13)1517; Hernandez AF, JAMA 2007;298(13):1525; Moss AJ, NEJM 2002;346(12):877-83; Bardy GH, NEJM 2005;352(3):225-37; Gregoratos G, Circ 2002;106:2145; Hunt SA, Circ 2005; 112

Objective Compare the proportion of women and men meeting trial criteria for the 1º prevention of SCD Hypothesis: More women than men meet strict trial criteria.

Data Source: NCDR-ICD™ Registry Initiated in 2005 Participation mandated by CMS for reimbursement for 1 o prevention ICD Standardized data elements and definitions –Patient characteristics –Device type and programming –Health system information –In-hospital outcomes

Study Population 115 Missing Gender 40,195 ICD for 2º Prev 8,228 Previous ICD Jan 2005-April 2007 Study Cohort

Outcome: Met Trial Criteria H/O Myocardial Infarction (MADIT-II) –MI > 40 days AND –LVEF ≤ 30% AND –NYHA I-III H/O Heart Failure (SCD-HeFT) –LVEF ≤ 35% AND –NYHA class II or III If NYHA IV –Met either above criteria AND –Intraventricular conduction delay AND –Biventricular ICD Moss AJ, NEJM 2002;346(12):877-83; Bardy GH, NEJM 2005;352(3):225-37; Gregoratos G, Circ 2002;106:2145; Hunt SA, Circulation 2005; 112

Analyses Compared baseline characteristics between women and men Assessed association between sex and concordance with trial enrollment criteria –Adjustment for demographics, clinical and health system characteristics Stratified by age

Baseline Characteristics Women N=16,079 Men N=43,754 Age (mean, +/- SD)67.6 ± ± 12* Ischemic cardiomyopathy * History of Heart Failure * NYHA: I II III IV * LVEF (mean, +/- SD)24.8 ± ± 7.8 Medicare/Medicaid * All expressed as a % unless otherwise stated *p<0.001

Unadjusted Analyses: Met Trial Criteria * *p<0.001 Proportion *

Multivariable Analysis: Met Trial Criteria Unadjusted +Admission Char +History, NYHA +Diagnostics +Physician Char +Hosp Char Fully Adjusted Fewer Women More Women OR (95% CI) 1.03 ( ) 1.01 ( ) 1.11 ( ) 1.09 ( )

Multivariable Analysis: Stratified by Age Fewer WomenMore Women Unadjusted Fully Adjusted Unadjusted Fully Adjusted OR (95% CI) 1.16 ( ) 1.10 ( ) 1.02 ( ) 0.94 ( ) Age<65 (n=20,285) Age≥65 (n=39,548) Interaction: p=0.002

Conclusions Most patients who receive ICD therapy for 1º prevention meet MADIT- II or SCD-HeFT criteria Women were slightly more likely than men to have met these criteria

Limitations Lack of denominator of potentially eligible patients Unable to examine referral bias or patient preferences Cases of 1º prevention for other indications

Comparison to Prior Studies Low representation of women in observational and clinical trials Recent study suggests fewer eligible women receive ICD for 1º prevention –OR 0.62, 95% CI Davis DR, Europace 2006;8:1054; Gauri AJ, Am J Med 2006;119:167.e17; Curtis LH, JAMA 2007; 298(13)1517; Hernandez AF, JAMA 2007;298(13):1525

Implications Characterize upstream factors affecting ICD implant Variation by age groups Importance of national registry for surveillance of cardiovascular technology