Shortfalls in MI Care Hit Lowest Socioeconomic Groups the Hardest

Despite considerable progress in improving the care of patients with MI across the socioeconomic spectrum, those from the most disadvantaged regions in the United States still have more adverse outcomes, longer times to angiography, and less chance of being referred to cardiac rehab, a new study concludes.

“This is shining a light on a systemic issue,” lead author Jacob A. Udell, MD, MPH (University of Toronto, Canada), told TCTMD. He added that the assumption at the start of the study was that the most disadvantaged patients in terms of lowest socioeconomic group would be primarily urban dwellers, but the reality was that many of the patients in the study came from rural neighborhoods, likely explaining much of the nearly threefold difference in time to angiography that was seen between the lowest and highest groups, as well as a nearly fourfold difference in use of fibrinolysis.

“These patients are just as represented in rural neighborhoods, and I think all of us are starting to appreciate this based on the last election results,” he added. More than 70% of patients in the lowest socioeconomic group were from the southern United States.

The study was published online May 30, 2018, in Circulation: Cardiovascular Quality and Outcomes.

Using data from US centers participating in the Acute Coronary Treatment and Intervention Outcomes Network Registry–Get With The Guidelines quality improvement program, Udell and colleagues looked at in-hospital mortality and MACE among 390,692 STEMI patients according to the neighborhoods in which they resided. Patients’ ZIP codes were linked to census information, and they were categorized into one of five groups of socioeconomic status: lowest, low, middle, high, and highest.

Patients in the highest socioeconomic neighborhoods were more likely to be older, male, white, urban dwellers, and to have private medical insurance. They were also more likely to present with STEMI. Those in the lowest category were younger, tended to be of minority race/ethnicity (38%), resided in equal proportions in rural and urban areas, and had a mix of private and governmental source of medical insurance coverage. Nearly 20%, however, were uninsured. Median annual household income differed by approximately $30,000 between the lowest and highest groups, and the percentage of adults who completed high school and/or college was disproportionately low in the lowest group compared with all other groups.

For the entire cohort, arrival time to angiography was approximately 4.5 hours. There was significant disparity across socioeconomic categories, with those in the lowest category averaging 8 hours from arrival to angiography versus 3.4 hours for those in the highest category. Similarly, thrombolytic therapy was used more frequently in the lowest socioeconomic group than in the highest (23.1% vs 5.9%) and the percentage who had a time to primary PCI of 120 minutes or less was lower (47.8% vs 72.3%), as were primary PCI rates (87.6% vs 94.4%), and referral to cardiac rehab (72.1% vs 78.2%).

Higher Risks of Major Bleeding and Mortality

After adjustment for insurance status as well as clinical and hospital variables, socioeconomic disadvantage was not associated with a lower rate of guideline-recommended in-hospital care.

“I think that is a great finding, that at least in these hospitals that are participating in this quality-care registry we are seeing decent care,” Udell said. “That said, those patients who came from the most disadvantaged neighborhoods, after adjustment for multiple risk factors, still had the highest risk of in-hospital death or major bleeding.”

Compared with the highest socioeconomic group, risk-adjusted in-hospital mortality was greater in the lowest group (OR 1.10; 95% CI 1.02-1.18). Major bleeding was also increased for the highest versus lowest group (OR 1.10; 95% CI 1.05-1.15) and versus the low group as well (OR 1.10;95% CI 1.05-1.15).

While the differences are not striking, Udell said, they are a reflection of ongoing care issues for the disadvantaged populations.

“This is timely because we’re looking at bundled payments, we’re looking at quality of care and reimbursement, and there’s a lot of controversy about whether to factor in socioeconomic status of the patient when deciding on whether a hospital should be graded on giving good care . . . and this really does suggest that we need to factor that in,” he concluded.