Greater CVD Risk Seen Among Individuals With SMI

With their study finding that the presence of a serious mental illness (SMI) is likely to increase the risk of cardiovascular disease (CVD), investigators from the University of Minnesota Medical School are stressing the importance of addressing major CV risk factors as early as possible.

Doing so can help to reduce both morbidity and mortality in patients with an SMI, including bipolar disorder, schizophrenia, or schizoaffective disorder, they emphasized.

This research was published online recently in Journal of the American Heart Association, and the investigators used diagnosis codes to differentiate patients with and without SMI who had a primary care visit between January 20, 2016, and September 19, 2018.

“A handful of studies have examined cardiovascular risk estimates in those with and without SMI, but most have used control populations from separate studies or general population estimates. This approach is suboptimal,” noted the authors. “As part of a cluster‐randomized trial aimed at reducing CV risk in patients with SMI, we collected baseline CV risk estimates for patients with and without SMI from the same clinic populations.”

From their final analysis that included 11,333 patients with SMI and 579,924 who did not have SMI, adjusting for demographics, vital signs, medication, diagnosis, and health insurance data showed there to be a greater mean 10-year incidence of CVD among patients with SMI compared to those with no SMI:

• Patients with SMI: 9.44% (95% CI, 9.29%-9.60%)
• Patients without SMI: 7.99% (95% CI, 7.97%-8.02%)

Individuals in the SMI group had to have at least 2 outpatient or at least 1 inpatient diagnostic code for SMI in the 2 years prior to study inclusion in their electronic health record, and CV risk was estimated using atherosclerotic cardiovascular disease risk (ASCVD) score (ages 40-75 years) for those with diagnosed ASCVD and Framingham risk score (ages 18-59 years) for those without diagnosed ASCVD.

The most common SMI was bipolar disorder (70.6%), followed by schizoaffective disorder (17.6%) and schizophrenia (11.7%). Patients with any SMI vs no SMI were also more likely to be younger (<65 years; 90.8% vs 86.8%); to self‐identify as Black (13.6% vs 9.3%), Native American/Alaskan Native (0.8% vs 0.36%), or multiple races (0.9% vs 0.4%); and to have Medicaid (26.7% vs 11.8%) or Medicare (10.7% vs 8.5%) coverage.

While the 10-year risk was almost equal between the SMI and non-SMI cohorts (8.0% vs 7.9%), respectively, the 30-year risk was significantly higher in the latter, as shown by the following:

• More patients with SMI had a CVD diagnosis, coronary heart disease, or hypertension, respectively: 4.6% vs 3.7% (P < .0001), 3.0% vs 2.6% (P = .015), and 14.9% vs 13.2% (P < .0001)
• More patients with SMI were likely to be classified as overweight or obese: 77.9% vs 68.8% (P < .0001)
• More patients with SMI were current smokers: 36.2% vs 12.1% (P < .0001)

A multivariate model that adjusted for age, race, ethnicity, sex, and insurance status demonstrated similar findings. Patients with SMI still had higher 10-year risks of ASCVD (8.31% vs 7.92%) and a 92% (HR, 1.92; 95% CI, 1.82-2.01; P < .0001) greater risk of “being in a higher‐risk group compared with patients without SMI,” the authors noted.

Considering the risk attributable to each SMI diagnosis covered by this study, the highest unadjusted 10-year CVD risk was seen among those with schizophrenia and the lowest, bipolar disorder. In contrast, the highest 10-year adjusted risk was seen among individuals with bipolar disorder and the highest 30-year risk was seen among persons with schizoaffective disorder.

Age was shown to have the greatest influence on 10-year risk—such that younger ages had a greater CVD risk—while adjusting for insurance status showed a risk decrease.

“The significantly increased cardiovascular risk associated with SMI is evident even in young adults,” the study authors emphasized. “This suggests the importance of addressing uncontrolled major cardiovascular risk factors in those with SMI at as early an age as possible.”

Strengths of their findings include their research being the first to estimate a lifetime risk of CVD in a large outpatient sample with SMI, that the risk differences are so significant compared with individuals who do not have an SMI diagnosis, and their use of the same study sample for patients with and without SMI. The principal limitation on generalizing their conclusions to a wider patient population is that they conducted their study within an integrated health care system.

Reference

Rossom RC, Hooker SA, O’Connor PJ, Crain AL, Sperl-Hillen JM. Cardiovascular risk for patients with and without schizophrenia, schizoaffective disorder, or bipolar disorder. J Am Heart Assoc. Published online March 9, 2022. doi:10.1161/JAHA.121.021444