Findings differ from what’s seen in other inflammatory diseases
Patients with inflammatory bowel disease (IBD) had no increased risk for acute myocardial infarction (MI) compared with the general population — or even with patients with other chronic inflammatory conditions, a researcher reported here.
Among hospitalizations included in the National Inpatient Sample from 2000 to 2011, 1.3% of patients with IBD were admitted for MI compared with 3.2% of the general population (P<0.001), according toEdward L. Barnes, MD, of Brigham and Women’s Hospital in Boston, and colleagues.
“In some studies, IBD has been linked with increased cardiovascular risks, including coronary artery disease and MI, yet traditional risk factors such as hyperlipidemia, obesity, and hypertension are less common among patients with IBD and questions remain regarding the true prevalence of events such as MI among this population,” Barnes said in a poster session.
To address this question, he and his colleagues identified 567,438 hospitalizations among IBD patients and 78,121,000 admissions for the general population during the study period.
Comparisons of patients with and without IBD demonstrated that IBD patients were younger (51.6 vs 57, P<0.001), and had significantly less hyperlipidemia (12.6% vs 18.4%, P<0.001), diabetes (12.4% vs 20.6%, P<0.001), and hypertension (26.9% vs 34.9%, P<0.001). They also had lower rates of obesity (4.7% vs 6.7%, P<0.001).
In an unadjusted model, the risk for MI among patients with IBD was 0.42 (95% CI 0.41-0.43) compared with the general population, Barnes reported.
And in a multivariate analysis that adjusted for risk factors including age, sex, race/ethnicity, hyperlipidemia, hypertension, obesity, Charlson comorbidity index, insurance, and tobacco use, the odds ratio for MI among patients with IBD was 0.54 (95% CI 0.52-0.55), Barnes reported.
In an additional unadjusted analysis, the risk for MI was lower among IBD patients than among those with SLE or RA:
- SLE: OR 1.74 (95% CI 1.69-1.80)
- RA: OR 2.32 (95% CI 2.26-2.38)
Risks were also lower in an adjusted multivariate analysis:
- SLE: OR 1.72 (95% CI 1.67-1.77)
- RA: OR 1.45 (95% CI 1.41-1.49)
As to why there shouldn’t be a similar risk for MI and CAD among patients with IBD compared with diseases such as SLE and RA that also are characterized by systemic inflammation, Barnes explained toMedPage Today that in patients with the latter two diseases, the cytokine/chemokine pattern seems to favor a risk on the arterial side, conferring a higher MI/CAD risk. In contrast, in the IBD population, the higher risk is for venous events.
For instance, it’s been shown that patients with IBD have a higher baseline rate than the general population for deep vein thrombosis (0.93% vs 0.66%, P<0.001) and pulmonary embolism (0.89% vs 0.76%,P<0.001). Moreover, they also less often had preventive surgery such as coronary artery bypass grafts (0.33% vs 0.94%, P<0.001).
“This is a hypothesis at this point,” Barnes noted. “It isn’t just systemic inflammation that leads to cardiovascular risk in diseases such as lupus, rheumatoid arthritis, and IBD. There appear to be differences in cytokines involved in the chronic inflammation.”