Rheumatoid Arthritis As a Risk Factor for Cardiovascular Events Following Hospitalized Pneumonia; A Population-Based Cohort Study

Mette Holland-Fischer¹, Ulrik Tarp², Reimar W. Thomsen³ and Mette Nørgaard³, ¹Department of Rheumatology, Aalborg University Hospital, Aalborg, Denmark, ²Department of Rheumatology, Aarhus University Hospital, AArhus, Denmark, ³Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark

Meeting: 2015 ACR/ARHP Annual Meeting

Date of first publication: September 29, 2015

Keywords: Cardiovascular disease, infection and rheumatoid arthritis (RA)

Session Information

Date: Sunday, November 8, 2015

Title: Epidemiology and Public Health Poster I: Comorbidities and Outcomes of Systemic Inflammatory Diseases

Session Type: ACR Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose: Cardiovascular disease is a major cause of morbidity and mortality in patients with Rheumatoid Arthritis (RA). Patients with RA do also have an increased risk of infections. Previous studies suggest that recent infection may trigger myocardial infarction and stroke, and this mechanism may be particularly important in patients with underlying low-grade inflammation such as RA. Our objective was to examine whether RA-patients have increased risk of cardiovascular events (CVE) following hospitalized pneumonia compared to patients with pneumonia without RA.

Methods: We conducted this population-based cohort study of adults with a first-time hospitalization with pneumonia between 1997 and 2011 in Northern Denmark. Information on RA, comorbidity, pneumonia and CVE was obtained from medical databases. Comorbidity data included the 19 conditions in the Charlson Index, alcoholism and previous diagnosis of CVE. We defined CVE as stroke or acute myocardial infarction. Data on mortality was ascertained from the Danish Civil Registration System. Cox regression was used to compute Hazard Ratios (HR) for CVE following hospitalization comparing patients with and without RA, controlling for sex, age, level of comorbidity, prior CVE, alcoholism, and antibiotic therapy before admission.

Results: A total of 75,087 patients were hospitalized with pneumonia. Among them 1677 (2.2%) had RA. All-cause mortality after 30 or 90 days did not differ between RA- and non-RA-patients with crude 30- and 90-day MRRs of 0.98 (95% CI: 0.87-1.11) and 0.99 (95% CI: 0.89-1.10) and adjusted MRRs of 0.99 (95% CI: 0.87-1.12) and 0.98 (95% CI: 0.88-1.09), respectively (table 1). A larger proportion of the RA-patients had prior CVE 18.1% (95% CI: 16.3-20.0) vs non-RA-patients 15.3% (95% CI: 15.1-15.6). Overall, we found no substantially higher risk of CVE following pneumonia among RA patients compared with non-RA patients (table 2). However, 8 to 30 days after pneumonia CVE risk tended to be increased in RA patients, with corresponding crude and adjusted HRs for CVE of 1.41 (95%CI: 0.94-2.12) and 1.32 (95%CI: 0.88-1.98) (table 2).

Conclusion: A larger proportion of RA patients with a first time hospitalization with pneumonia had prior CVE compared to pneumonia patients without RA. The risk of new CVE 8 to 30 days after pneumonia admission tended to be increased in RA patients.

Table 1 Characteristics of 75087 patients hospitalized for pneumonia from 1997 to 2011 in Northern Denmark
	Rheumatoid Arthritis	No Rheumatoid Arthritis
N	1677 (2.2%)	73410 (97.8%)
Age (years), mean	72.2	69.2
Sex*
Women	1099 (65.5%)	34306 (46.7%)
Men	578 (34.5%)	39104 (53.3%)
Comorbidity index* (Charlson index score)
Low (0)	552 (32.9 )	30829 (42.0%)
Medium (1-2)	744 (44.4%)	28335 (38.6%)
High (≥3)	381 (22.7%)	14246 (19.4%)
Prior cardiovascular event*	303 (18.1%)	11235 (15.3%)
Systemic antibiotic therapy* before admission	555 (33.1%)	21890 (29.8%)
30-day mortality*	242 (14.4%)	10773 (14.7%)
90-day mortality*	357 (21.3%)	15759 (21.5%)
Crude 30-day MRR	0.98 (CI:0.87-1.11)
Crude 90-day MRR	0.99 (CI:0.89-1.10)
Adjusted 30-day MRR	0.99 (CI:0.87-1.12)
Adjusted 90-day MRR	0.98 (CI:0.88-1.09)
*Data presented as number of patients and proportion (%)

Table2 CVE following hospitalized pneumonia
	RA	Non-RA	Crude HR	Adjusted HR^
N	1677	73410
Patients with CVE on or 1-7 days after admission with pneumonia	105 (6.3%)*	4917 (6.7%)	1.04 (95%CI:0.86-1.26)	1.01 (95%CI:0.84-1.23)
Patients with CVE 8-30 days after admission with pneumonia	24 (1.4%)*	853 (1.2%)*	1.41 (95%CI:0.94-2.12)	1.32 (95%CI:0.88-1.98)
Patients with CVE 31-90 days after admission with pneumonia	17 (1.0%)*	832 (1.1%)*	1.00 (95% CI:0.62-1.62)	0.94 (95% CI:0.58-1.52)
Patients with CVE 91-180 days after admission with pneumonia	13 (0.8%)*	645 (0.9%)*	0.98 (95% CI:0.57-1.70)	0.92 (95% CI:0.53-1.60)
*Data presented as number of patients and proportion (%) ^ Adjusted for sex, age, level of comorbidity, prior cardiovascular events, alcoholism and antibiotics before admission CVE: cardiovascular event

Disclosure: M. Holland-Fischer, None; U. Tarp, None; R. W. Thomsen, None; M. Nørgaard, None.

To cite this abstract in AMA style:

Holland-Fischer M, Tarp U, Thomsen RW, Nørgaard M. Rheumatoid Arthritis As a Risk Factor for Cardiovascular Events Following Hospitalized Pneumonia; A Population-Based Cohort Study [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/rheumatoid-arthritis-as-a-risk-factor-for-cardiovascular-events-following-hospitalized-pneumonia-a-population-based-cohort-study/. Accessed .

« Back to 2015 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/rheumatoid-arthritis-as-a-risk-factor-for-cardiovascular-events-following-hospitalized-pneumonia-a-population-based-cohort-study/