Abstract 16579: Readmission Rates for Acute Coronary Syndrome and Mortality after PCI for STEMI: The Influence of Socioeconomic Status

Abstract

Objectives Primary percutaneous coronary intervention (PCI) is a preferred treatment ST-segment elevation myocardial infarction (STEMI).We studied the influence of income on the stent used, readmission rates for acute coronary syndrome (ACS), and mortality. Methods Patients (pts) admitted for STEMI who received PCI with either bare metal stent (BMS) or drug eluting stent (DES) (n=11,656) in New Jersey (NJ) between 2003 and 2009 were identified from the Myocardial Infarction Data Acquisition System database (MIDAS). IRS Income and Tax Filing Record was used to obtain average income for each NJ zip code and were grouped into quintiles (low to high, Q1-Q5). Pts zip code was used as the linkage for merging MIDAS and income quintiles. Outcomes including readmissions for ACS and mortality were assessed at 30 days and one year after discharge from the index hospitalization. Multivariate logistic and survival analysis were used to determine the impact of income on type of stents used, readmission and mortality at 1-year. Results Sixty percent of STEMI pts undergoing primary PCI received DES, and income had no effect on the type of stent selected (OR: 0.98, 95% CI: 0.95 - 1.01). Readmission for ACS at 30 days was higher in BMS pts (11.8% vs 10.3%; HR: 0.84, 95% CI: 0.73-0.96) and income had no significant effect. Between 30-day to 1-year follow-up, DES pts in the lowest income quintile (Q1) were twice as likely to be readmitted for ACS compared to those in the highest quintile (2.6% vs 1.3%, HR: 2.1, 95% CI; 1.1-4.0). BMS pts had similar readmission rates across different income quintiles. Compared to pts who received a DES, mortality rates in-hospital, 30-day and 1-year were higher among BMS pts irrespective of income quintiles (in-hospital: 3.3% vs 5.5%, 30-day: 3.8% vs 6.5%, 1-year: 5.9% vs 9.4%, all P<0.0001). Readmission for ACS at 30 days was associated with 42% higher risk of death at one year after controlling for income quintile and other covariates (HR: 1.42, 95% CI: 1.07 - 1.88). Conclusions Among STEMI patients undergoing primary PCI, income had no effect on type of stent selected. Patients with lower income and DES had higher readmission rates up to 1 year. Socioeconomic status plays an important role on early readmission and therefore increasing mortality risk.