Background/Purpose: Cardiovascular disease remains the
most common cause of mortality in Systemic lupus erythematosus (SLE). Some
studies suggest that mortality due to acute myocardial infarction (AMI) in SLE
has decreased. We aimed to evaluate temporal trends of incidence and mortality
of SLE in AMI hospitalizations in a nationally representative sample.

Methods: We reviewed Nationwide Inpatient
Sample (NIS) data over 10 year period from 2002-2011 for adult AMI
hospitalizations as a primary diagnosis with SLE as secondary diagnosis using
validated ICD9-CM codes. We calculated unadjusted proportions of mortality
yearly and used survey logistic regression to calculate adjusted odds ratios (aOR) for hospital mortality overall and after stratifying
for age (≤50 vs. >50).

Results: We identified a total of 6588743 AMI hospitalizations from 2002-2011 of which 20508 (0.31%) had a
diagnosis for SLE. The proportion of patients with SLE in AMI hospitalizations
increased from 0.27% in 2002 to 0.39% in 2011.  SLE hospitalizations were
younger (60.5 vs. 67.8 years<0.01); more female (80.4% vs. 40.1%;
p<0.01); with a higher proportion of African-Americans (21.4% vs. 9.2%;
p<0.01) and a higher Charlson comorbidity index
(Mean 2 vs. 1.5; p<0.01). The
unadjusted mortality rates in SLE hospitalizations yearly were similar to
hospitalizations without SLE (Figure 1). After adjusting for age, gender, race, Charlson comorbidity index, hospital level characteristics,
cardiac procedures, SLE hospitalizations had similar odds-ratio for hospital
mortality (aOR=0.98; 95% CI= 0.83-1.16; p=0.54)
compared to non-SLE hospitalizations. In hospitalizations ≤50 years,
there was no significant difference in the adjusted odds of hospital mortality
(aOR=0.88; 95% C 0.56-1.37; p=0.57)

Conclusion:  In hospital mortality in SLE
hospitalizations with AMI was similar to non-SLE hospitalizations. This could
be related to better disease recognition, newer modalities, risk modification
and increased life expectancy in SLE patients.

Figure 1
Proportion of Mortality in AMI Hospitalizations Stratified by Systemic Lupus
Erythematosus Status