Scherrer and colleagues studied a retrospective cohort of 15,634 patients (93% men and 7% women) who had rheumatoid arthritis (RA; ages 30-79 years). The patients were drawn from the Department of Veterans Affairs (VA) national administrative and pharmacy databases between 1999 and 2006, and they all had a record of using a disease-modifying antirheumatic drug.
Patients were free of cardiovascular disease for 2 years before any diagnosis of RA or depression. The authors classified patients with RA as "depressed" if they had made 2 or more visits for a depression diagnosis following RA diagnosis, but before the onset of an outpatient or inpatient ICD-9-CM code for myocardial infarction (MI). Therefore, the effect of depression was expected to be an independent predictor of MI in a maximum 6-year follow-up period. Analyses were adjusted for patient sociodemographic characteristics (age, gender, race, insurance, and marital status) and known MI risk factors (eg, posttraumatic stress disorder, obesity, hyperlipidemia, hypertension, diabetes, tobacco dependence).
Depressed patients with RA without a history of cardiovascular disease were 40% more likely to have a MI compared with those without depression. Age and risk factors (ie, diabetes, hypertension, hyperlipidemia) excluding obesity were significant risk factors for MI. RA disease severity (based on the number of orthopaedic surgeries and the number of intra-articular injections) was also predictive of MI.
About 19% of patients with RA who were beginning treatment have depression.[1] Comparatively, the general population has about a 5% prevalence of depression.[2] Because depression is an independent risk factor for incident heart disease,[3] patients with RA and depression may be at increased risk for heart disease compared with patients with RA without depression. The cardiovascular risks can be aggravated by both RA and depression, as well as by poor treatment adherence, increased inflammation, hypertension, hyperlipidemia, and unhealthy lifestyles. Furthermore, depression is an independent risk factor for mortality in patients with RA.[4]
The authors recognize potential study limitations. Results may not be generalizable to all patients with RA with a previous depression diagnosis because the study only included patients with RA who were previously free of cardiovascular disease and in whom new-onset depression developed. Use of administrative data has inherent limitations when compared with the more reliable in-person clinical assessments and clinical trials. Although misclassification leading to over- or under-diagnoses of comorbidities because of depression could be possible, the authors verified that the prevalence in their study cohort was similar to other studies. Finally, data on non-VA healthcare utilization is lacking.
This study determined that patients with RA in whom depression develops are at increased risk for incident MI compared with those in whom depression does not develop. Whether depression is also a risk factor for heart attacks and how depression is managed in patients with RA from the general population needs further study.
This study has important implications for providers and payers. The high cost of heart disease[5] and the independent contribution of depression to MI in patients with RA from this study call for increased screening for depression and heart disease status among these patients, which may improve quality of care and reduce costs.
I think I will call a cardiologist. Yikes!