Background

Access to reliable transportation is fundamental in the management of chronic disease. The purpose of this study was to investigate the association between vehicle ownership at the neighborhood-level and long-term mortality after myocardial infarction (MI).

Methods

This is a retrospective observational study evaluating adult patients admitted for MI between January 1st, 2006, and December 31st, 2016. Neighborhoods were defined by census tract and household vehicle ownership data was obtained from the American Community Survey courtesy of the University of California, Los Angeles Center for Neighborhood Knowledge. Patients were divided into 2 groups: those living in neighborhoods with higher vehicle ownership, and those living in neighborhoods with lower vehicle ownership. The cutoff of 4.34% of households reporting not owning a vehicle was used to define a neighborhood as one with "higher" vs "lower" vehicle ownership as this was the median value for the cohort. The association between vehicle ownership and all-cause mortality after MI was assessed using Cox proportional hazards regression models.

Results

A total of 30,126 patients were included (age 68.1 +/- 13.5 years, 63.2% male). After adjusting for age, sex, race/ethnicity, and medical comorbidities, lower vehicle ownership was associated with increased all-cause mortality after MI (hazard ratio [HR] 1.10; 95% confidence interval [CI] 1.06-1.14; p<0.001). This finding remained significant after adjusting for median household income (HR 1.06; 95% CI 1.02-1.10; p = 0.007). Upon comparison of White and Black patients living in neighborhoods with lower vehicle ownership; Black patients were found to have an increased all-cause mortality after MI (HR 1.21, 95% CI 1.13-1.30, p<0.001), a difference which remained significant after adjusting for income (HR 1.20; 95% CI 1.12-1.29; p<0.001). There was no significant difference in mortality between White and Black patients living in neighborhoods with higher vehicle ownership.

Conclusion

Lower vehicle ownership was associated with increased mortality after MI. Black patients living in neighborhoods with lower vehicle ownership had a higher mortality after MI than White patients living in similar neighborhoods but Black patients living in neighborhoods with higher vehicle ownership had no worse mortality than their White counterparts. This study highlights the importance of transportation in determining health status after MI.

Objective

We sought to identify sub-groups of "low-risk" HEART score patients (history, ECG, age, risk factors, and troponin) at elevated risk of acute myocardial infarction or death within 30 days.

Methods

We performed a secondary analysis of prospective emergency department (ED) encounters for suspected acute coronary syndrome in a large health system with low-risk HEART scores (0-5 points). Logistic regression using the 5 components of the HEART score analyzed the increase risk attributable to points from each of the 5 score components.

Results

Of 30,971 encounters among 28,992 unique patients, 135 (0.44%, 95% confidence interval [CI] = 0.37-0.51) experienced acute myocardial infarction or death. Risk increased for each component of the HEART score from 0 to 1 to 2 points (history, 0.4% to 0.5% to 0.6%; ECG, 0.3% to 0.7% to 0.7%; age, 0.2% to 0.3% to 0.7%; risk factors, 0.1% to 0.4% to 0.8%), except troponin, which had the highest risk with 1 point (troponin, 0.4% to 2.7% to 0.9%). Odds ratios from our regression, which adjusts for other components, showed a similar pattern (from 1 vs 0 and 2 vs 0 points, respectively: history, 1.0 and 1.8; ECG, 2.2 and 3.5; age, 1.2 and 2.1; risk factors, 2.4 and 4.2; and troponin, 6.0 and 3.6).

Conclusion

Among "low-risk" suspected acute coronary syndrome encounters, increasing points within each of the 5 categories demonstrated small increases in risk of death or acute myocardial infarction, with the troponin and ECG components representing the largest risk increases.

Study objective

We compare clinical management and outcomes of emergency department (ED) encounters by sex after implementation of a clinical care pathway in 15 community EDs that standardized recommendations based on patient risk, using the History, ECG, Age, Risk Factors, and Troponin (HEART) score.

Methods

This was a retrospective analysis of adult ED encounters evaluated for suspected acute coronary syndrome with a documented HEART score from May 20, 2016, to December 1, 2017. The primary outcomes were hospitalization or 30-day stress testing. Secondary outcomes included 30-day acute myocardial infarction or all-cause death (major adverse cardiac event). A generalized estimating equation regression model was used to compare the odds of hospitalization or stress testing by sex; we report HEART scores (0 to 10) stratified by sex and describing major adverse cardiac events.

Results

A total of 34,715 adult ED encounters met the inclusion criteria (56.0% women). A higher proportion of women were classified as low risk (60.5% versus 52.4%; odds ratio [OR] 1.39; 95% confidence interval [CI] 1.33 to 1.45). Women were hospitalized or received stress testing less frequently than men for low HEART scores (18.8% versus 22.8%; OR 0.79; 95% CI 0.73 to 0.84) and intermediate ones (46.7% versus 49.7%; OR 0.88; 95% CI 0.83 to 0.95), but similarly for high-risk ones (74.1% versus 74.4%; OR 0.99; 95% CI 0.77 to 1.28). Women had 18% lower odds of hospitalization or noninvasive cardiac testing (OR 0.82; 95% CI 0.78 to 0.86), even after adjusting for HEART score and comorbidities. Men had higher risks of major adverse cardiac events than women for all HEART score categories but the risk for men was significantly higher among low-risk HEART scores (0.4% versus 0.1%).

Conclusion

Women with low-risk HEART scores are hospitalized or stress tested less than men, which is likely appropriate, and women have better outcomes than men. Use of the HEART score has the potential to reduce sex disparities in acute coronary syndrome care.