Rheumatoid Arthritis Associated With Lower in-Hospital Mortality in Acute Myocardial Infarction

An increase in hospitalizations for acute myocardial infarction-rheumatoid arthritis was observed between 2002 and 2016, with rheumatoid arthritis found to be independently associated with lower in-hospital mortality in patients with acute myocardial infarction, especially for those with ST-elevation myocardial infarction (STEMI), according to study results published in the American Journal of Medicine.

Rheumatoid arthritis is the most common type of inflammatory arthritis and patients with this disease are at increased risk for cardiovascular events and cardiac mortality compared with the general population. There is limited data on the outcomes of acute myocardial infarction in patients with rheumatoid arthritis.

In this study, the National Inpatient Sample database was searched for hospitalizations for acute myocardial infarction that occurred between 2002 and 2016 to determine the trends and outcomes for patients admitted for acute myocardial infarction alone vs with comorbid rheumatoid arthritis. Patients aged < 18 years, those with diagnostic codes for other inflammatory conditions (eg, connective tissue diseases or HIV/ AIDS), and those with missing data on in-hospital mortality or baseline characteristics were excluded from analysis.

A total of 9,359,546 hospitalizations with acute myocardial infarction occurred during that time period, of which 123,783 patients (1.3%) had comorbid rheumatoid arthritis (30.9% with STEMI; 69.1% with non-STEMI [NSTEMI]).

There was an increase in the number of hospitalizations with acute myocardial infarction-rheumatoid arthritis, from 6730 in 2002 to 10,829 in 2016 (P_trend <.001), as well as for NSTEMI-rheumatoid arthritis (P_trend <.001). There was a downtrend in in-hospital mortality rates for acute myocardial infarction-rheumatoid arthritis (from 5.8% in 2002 to 5.2% in 2016, P_trend =.01), which corresponded to the increase in the use of percutaneous coronary intervention (P_trend <.001).

An independent association was established between the presence of rheumatoid arthritis and lower in-hospital mortality in patients with acute myocardial infarction (adjusted odds ratio, 0.90; 95%CI, 0.81-0.99; P =.03). This association was stronger in patients with STEMI-rheumatoid arthritis vs STEMI—no rheumatoid arthritis. Mortality was comparable in patients with NSTEMI-rheumatoid arthritis and those with NSTEMI-no rheumatoid arthritis.

Limitations of the study include selection bias, the possibility of unmeasured confounders, as well as a lack of long-term outcomes data in the administrative database used.

”[O]ur analysis addresses an important knowledge gap in literature, regarding the contemporary outcomes of acute myocardial infarction in rheumatoid arthritis,” noted the study authors.

Reference

Elbadawi A, Ahmed HH, Elgendy IY, Omer MA, Ogunbayo GO, Hamed S, et al. Outcomes of acute myocardial infarction in patients with rheumatoid arthritis (published online April 9, 2020). Am J Med. doi:10.1016/j.amjmed.2020.02.039