ORLANDO – conducted by researchers at Case Western Reserve University, Cleveland.*
It’s generally accepted that psoriasis increases the risk of cardiovascular disease (CVD), but it’s not clear who’s most at risk. “We really wanted to find something that is cheap and easy to risk stratify these patients” said lead investigator Rosalynn Conic, MD, of Case Western’s department of dermatology.
Red blood cell distribution width (RDW) – a measure of the range of red blood cell volumes in a given sample – and mean platelet volume (MPV) fit the bill. In many places, they are already routinely reported on CBCs, so there’s no need for any special equipment or tests. Meanwhile, RDW and MPV elevations have been previously linked to CVD risk in the HIV and cardiology literature. The investigators wondered if they’d find a similar association in psoriasis, so they queried nearly 40,000 patients in the Explorys electronic health record database.What they found was “very impressive, for sure,” Dr. Conic said at the International Investigative Dermatology meeting.
The incidence of MI was highest among the 1,920 patients (5%) with elevated RDW and MPV (odds ratio, 3.4; 95% confidence interval, 2.7-4.2; P less than .001), followed by the 7,060 (18%) patients with high RDW and normal MPV (OR, 2.4; 95% CI, 2.1-2.8; P less than .001), as compared with normal/low MPV and RDW patients.
Elevated RDW or elevated RDW plus MPV increased the odds of atrial fibrillation, coronary artery disease, heart failure, and peripheral vascular disease anywhere from 2 to 8.3 times (P less than .001). Among psoriatic arthritis patients, elevated RDW almost doubled the risk of MI (OR, 1.8; P less than .001). Results were adjusted for age, gender, and hypertension.
In a subanalysis of treatment effects, 4 of 23 psoriasis patients at Case Western had elevated RDWs at baseline. Values normalized in the three patients who achieved a 75% reduction in the Psoriasis Area and Severity Index score after about a year of systemic treatment.