Circulation: Socioeconomics trump age, sex for post-CABG mortality
Regardless of race or sex, those with a lower socioeconomic position (SEP) have greater mortality rates five to 10 years after heart surgery compared with patients of a higher SEP, based on study results published April 6 in Circulation: Cardiovascular Quality and Outcomes.

Colleen G. Koch, MD, and her colleagues from the Cleveland Clinic evaluated 23,330 patients (15,156 white men, 6,932 white women, 678 black men and 564 black women), who underwent CABG between Jan. 1, 1995, and Dec. 30, 2005,  to identify the drivers of risk-adjusted mortality.

“Metrics such as income, value of housing and level of education are considered sensitive, private information that is rarely included in medical records,” the authors wrote. “Yet, SEP may be an important barrier to cardiovascular health rather than biologically implausible surrogates of race and sex.”

During the study, the researchers examined race-sex-related differences of SEP, assessed the impact on mortality post-cardiac surgery and looked at whether these risk factors were related to demographic or socioeconomic factors.

The researchers used data from the 2000 U.S. Census to evaluate socioeconomic stature by assessing six categories: household income; value of housing units; households receiving interest, dividend or rental income; number of adults older than 25 who completed high school and also those who finished college; and the number of people 16 years old or older who were employed in an executive, managerial or specialty occupation.

While white women were older, black men presented with higher rates of MI. Both black men and women had higher rates of left ventricular dysfunction, heart failure and presented more frequently for emergency surgery compared to the others. Additionally, black men and women had higher frequencies of hypertension, previous stroke, diabetes and renal disease compared to white women and men.

The primary endpoint of the study was death and the average follow-up was 5.8 years.

Regarding socioeconomic position, black patients and women exhibited overall lower socioeconomic status for all six indicators--this factor resulted in higher rates of mortality 10 years after surgery.

After adjusting for high blood pressure and diabetes, results showed that patients of the lowest socioeconomic stature had a 19 to 26 percent greater risk of dying five years after surgery compared to those of higher socioeconomic position.

“We were surprised that consistently and pervasively, through every way of looking at the data, it turns out this isn’t about skin color or gender. It’s about being poor,” said Koch.

Additionally, the results showed that overall black men had the worst survival rates, and white women had much lower survival rates than white men.

The researchers found these results concerning, as white women have better expected survival rates than men. Researchers attributed the reason to these patients receiving suboptimal care post-surgery.

“Socioeconomic disparity clearly influences an individual patient’s health, and in our investigation this is reflected in inferior survival after cardiac surgery for socioeconomically disadvantages patients,” the authors wrote. “Hence, although it is convenient to label patients by skin color and sex, it is factors that relate to SEP (poor education, low income, inadequate housing, lack of discretionary funds for investment and not being ‘in charge’ at work) that are more important.”

The authors concluded that the bigger focus should extend to socioeconomically disadvantaged patients “regardless of race and patient and health system factors that create disparity in health outcomes.”

Increasing the highly underutilized system of cardiac rehabilitation could help reduce mortality rates, raise outcomes and better manage risk factors, Koch noted.