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, MSPHAssistant Professor of Medicine, Cardiology DivisionUniversity 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 1o prevention ICD• Standardized data elements and definitions

– Patient characteristics– Device type and programming– Health system information– In-hospital outcomes

Study Population

108,341

85,730

59,833

16,079 (26.9%)Women

43,754 (73.1%)Men

115 Missing Gender40,195 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 CharacteristicsWomen

N=16,079Men

N=43,754

Age (mean, +/- SD) 67.6 ± 13 68.2 ± 12*

Ischemic cardiomyopathy 51.1 71.6*

History of Heart Failure 88.3 83.2 *

NYHA: I II III IV

7.329.857.25.8

10.1*35.350.04.7

LVEF (mean, +/- SD) 24.8 ± 8.5 24.9 ± 7.8

Medicare/Medicaid 77.3 75.3*

All expressed as a % unless otherwise stated *p<0.001

Unadjusted Analyses:Met Trial Criteria

0

10

20

30

40

50

60

70

80

90

100

Overall NYHA criteria EF criteria MI > 40 days

Women

Men

*

*p<0.001

Pro

port

ion

*

Multivariable Analysis: Met Trial Criteria

0.5 1.0 1.5

Unadjusted

+Admission Char

+History, NYHA

+Diagnostics

+Physician Char

+Hosp CharFully Adjusted

Fewer Women More Women

OR (95% CI)

1.03 (0.98-1.08)

1.01 (0.96-1.01)

1.11 (1.05-1.17)

1.09 (1.03-1.15)

1.09 (1.03-1.15)

1.09 (1.03-1.15)

Multivariable Analysis: Stratified by Age

0.5 1.0 1.5Fewer Women More Women

Unadjusted

Fully Adjusted

Unadjusted

Fully Adjusted

OR (95% CI)

1.16 (1.08-1.25)

1.10 (1.03-1.18)

1.02 (0.93-1.12)

0.94 (0.86-1.02)

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 0.56-0.68

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