Admissions for acute myocardial infarction with rheumatoid arthritis on the rise

While hospitalizations are on the rise for acute myocardial infarction (AMI) patients with rheumatoid arthritis, rates of in-hospital mortality seem to be decreasing, a new study has found.

Drawing from the National Inpatient Sample database of the US, researchers identified 9,359,546 hospitalizations due to AMI. The main outcome of interest was the temporal change in AMI hospitalizations with rheumatoid arthritis, as well as in-hospital mortality in this population. Other endpoints included cardiac arrest and mechanical circulatory support use.

Among all AMI hospitalizations, 123,783 (1.3 percent) had concurrent rheumatoid arthritis. A further 30.9 percent (n=38,815) of this subpopulation had ST-elevation myocardial infarction (STEMI).

From 2002 to 2016, researchers documented an increase in the number of AMI hospitalizations with rheumatoid arthritis, jumping from 6,730 to 10,829 (p_trend<0.001). This coincided with a significant downtrend in the hospitalizations for AMI without rheumatoid arthritis (p_trend=0.01).

Despite a ballooning hospitalization rate, AMI-rheumatoid arthritis patients seemed to enjoy improving outlook: rates of percutaneous coronary intervention grew (28.2 percent to 41.6 percent; p_trend<0.001), leading to a declining in-hospital mortality rate (5.8 percent vs 5.2 percent; p_trend=0.01).

Fully adjusted multivariable regression analysis revealed that rheumatoid arthritis was significantly protective against mortality risk in AMI patients (odds ratio, 0.90, 95 percent confidence interval, 0.81–0.99; p=0.03).

“Further studies are needed to evaluate the long-term outcomes of AMI among patients with rheumatoid arthritis,” researchers said.