A recent study published in Ophthalmology evaluated whether the Pooled Cohort Equations (PCE) cardiovascular risk score can accurately predict an increased risk of ocular diseases.
Give me some background on PCE.
PCE score was introduced in 2013 as a sex- and race-specific tool for estimating 10-year absolute rates of atherosclerotic cardiovascular disease (ASCVD) events in a primary prevention population.
The risk estimates are derived from a combination of established cardiovascular risk factors, including:
- Age
- Sex
- Race
- Smoking status
- Hypertension treatment status
- Cholesterol levels
- Blood pressure
- Smoking status
- Diabetes
As the PCE score utilizes information collected during routine primary care exams, it may act as a helpful tool for identifying patients who would benefit from earlier eye exams and potentially prevent blindness in high-risk individuals.
Now talk about the study.
In this retrospective cohort study, investigators utilized electronic health record (EHR) data from the All of Us (AoU) Research Program to elucidate the association between PCE score and risk of the following ocular diseases:
- Age-related macular degeneration (AMD)
- Glaucoma
- Diabetic retinopathy (DR)
- Retinal vein occlusion (RVO)
- Hypertensive retinopathy (HTR)
The study included a total of 35,909 adults aged 40-79 years with complete variables for PCE calculation within a 6-month period between 2009 and 2015.
Individual-level PCE score was computed and categorized into four PCE risk categories:
- Low (<5%)
- Borderline (5-7.4%)
- Intermediate (7.5-19.9%)
- High (≥20%)
Findings?
Higher PCE risk categories were significantly associated with increased risk of ocular diseases.
In the primary models, compared with the low-risk group, the high-risk group had the highest hazard ratios for ocular diseases (all P < 0.001):
- AMD: 6.22
- DR: 5.93
- HTR: 4.47
- RVO: 3.38
- Glaucoma: 2.33
Adjusted C-indices were highest for AMD (0.720), DR (0.751), and HTR (0.768), and moderate for glaucoma (0.625) and RVO (0.654). The cardiovascular score performed particularly well at predicting DR, HTR, and AMD.
Note: C-index (concordance index) is a mathematical test that can be used to evaluate the performance of a predictive algorithm (like PCE).
- Performance is measured on a scale of 0-1, where 1 represents perfect performance and 0 represents failed performance.
Anything else?
Findings were consistent in follow-up periods ranging from 5 to 7 years.
The PCE-AMD association was largely explained by age, whereas associations for DR and HTR remained robust.
Expert opinion?
These findings “give us an opportunity to identify high-risk patients early, when preventive measures might still protect their vision. The beauty of this approach is that it requires no additional testing; the information is already there in the medical record,” explained Anne L. Coleman, MD, PhD, senior author of the study and chair of the Department of Ophthalmology at UCLA Health.
Take home.
These findings suggest that in the AoU population, the single composite metric PCE meaningfully stratifies future risk for multiple ocular diseases, using information already available in primary care.
Meaning: PCE could be incorporated into primary care settings to identify individuals who could benefit from earlier ophthalmologic evaluation and prevention strategies.
Next steps?
Further research is required to determine the optimal timing and frequency of eye exams for different risk groups, and whether earlier detection and interventions based on cardiovascular risk can actually help prevent vision loss.
- Implementation studies could help integrate this risk stratification approach into routine primary care workflows and EHR systems.