Adults with psoriasis, especially younger patients with severe psoriasis, appear to be at increased risk for a myocardial infarction, according to an article in the October 11 issue of the Journal of the American Medical Association.

Psoriasis is a common, chronic, disease that affects about 2 percent to 3 percent of the adult population. It is associated with increased levels of markers of systemic inflammation such as increased C-reactive protein, according to background information in the article.

Several hospital-based studies have indicated that psoriasis is associated with a higher prevalence of cardiovascular diseases, including myocardial infarction, but these studies did not control for major cardiovascular risk factors.

Joel M. Gelfand, MD, and colleagues from the University of Pennsylvania, Philadelphia, conducted a prospective population-based cohort study to determine the risk of myocardial infarction in patients with psoriasis when controlling for major cardiovascular risk factors.

The study, which included 556,995 control patients, 127,139 patients with mild psoriasis and 3,837 with severe psoriasis compared outcomes among patients with and without a diagnosis of psoriasis. The patients, who lived in the United Kingdom, were 20 to 90 years of age.

Adjustments were made for hypertension, diabetes, history of prior infarction, hyperlipidemia, age, sex, smoking, and body mass index. Up to five controls without psoriasis were randomly selected from the same practices and start dates as the patients with psoriasis.

The researchers found that the incidence of myocardial infarction was higher in patients with severe psoriasis (5.13 infarctions per 1,000 person-years) and mild psoriasis (4.04 infarctions per 1,000 person-years) compared with control patients (3.58 infarctions per 1,000 person-years), with the highest rate in patients who were younger and had severe psoriasis.

For example, a 30-year-old patient with mild psoriasis had a 29-percent greater risk than a peer without psoriasis; a 30-year-old patient with severe psoriasis had about three times the risk of a peer without psoriasis. A 60-year-old patient with severe psoriasis had a 36-percent increased risk for heart attack.

"The magnitude of association between severe psoriasis and myocardial infarction in those patients younger than 50 years is similar to the magnitude of association for other major cardiac risk factors," the authors wrote.

"Our findings are novel and therefore it is important that additional studies be performed to confirm these results and determine their therapeutic implications. In particular, it is important to determine the impact of clinical markers of psoriasis activity, such as body surface area, as well as biomarkers of systemic inflammation (e.g., C-reactive protein) on the risk of myocardial infarction in patients with psoriasis. In the meantime, as part of good medical care, patients with psoriasis should be encouraged to aggressively address their modifiable cardiovascular risk factors," the researchers concluded.