Utility of Pooled Cohort Equations Useful in Determining Risk of Cancer and CVD

Seamus P. Whelton, MD, MPH

While the rate of cardiovascular disease (CVD) has declined over time, investigators in a recent study noted the rate of non-CVD mortality, including cancer, has remained constant.

Led by Seamus P. Whelton, MD, MPH, Johns Hopkins Ciccarone Center for Prevention of Cardiovascular Disease, investigators concluded the importance of PCE in determination of the risk prediction of CVD and cancer.

Study

The team used the Pooled Cohort Equations (PCE) individual 10-year atherosclerotic cardiovascular disease (ASCVD) risk estimate in their investigation.

For the study population, investigators used the Multi-Ethnic Study of Atherosclerosis (MESA), a community-based cohort comprised of participants free of CVD at baseline and aged 45 - 84 years.

Patients were excluded from analysis if they had cancer at baseline (n = 543), or other diseases suggestive of possible underlying undiagnosed cancer including emphysema (n = 90), liver disease (n = 210), or prior blood clots (n = 119).

Investigators identified 5773 patients without baseline CVD or cancer from the MESA, with a mean age of 61.5 years and 53% women.

They measured primary outcomes as the time to first event of incident CVD, including incident or fatal coronary heart disease (myocardial infarction, resuscitated cardiac arrest, fatal coronary heart disease), incident or fatal stroke, as well as incident cancer.

The team noted patients were removed from the dataset after diagnosis of incident CVD or incident cancer. They were contacted by telephone every 9 – 12 months and questioned about new hospitalizations, outpatient diagnoses, procedures, or death.

Investigators calculated participants PCE risk scores as low/borderline <7.5%, intermediate 7.5-<20%, and high ≥20% based on the 2018 ACC/AHA Cholesterol Guidelines.

Further, incident CVD and cancer event rates per 1000 person-years of follow-up were stratified by PCE-defined risk categories and calculated the cumulative incident function (CIF).

Results

Data show 715 incidence CVD events and 613 incident diagnoses of cancer during the 11.3-year follow-up, with 113 participants who developed both CVD and cancer. Of this number, 68 (60%) developed CVD before cancer

The team noted mean PCE risk was 12.8%, with 78% of participants with a PCE risk of <20%.

Further, individuals with a PCE risk of <7.5% had a higher proportion develop incidence cancer (6.2%) compared to incident CVD (4.3%).

The proportion of individuals with incident CVD versus incident cancer was higher when PCE risk was between 7.5% - 20%, (CVD 13.6%, cancer 10.4%), as well as when it was ≥20% (CVD 23.3%, cancer 14.8%).

In addition, patients with <7.5% PCE risk had 4.8% rate of incident cancer versus 3.3% rate of incident CVD per 1,000 person-years follow-up.

Investigators noted the rate of CVD (11.5%) was higher than cancer (8.6%) for PCE between 7.5% – 20%. The ratio of CVD to cancer increased logarithmically and at a PCE risk of 7.2%, the risk of cancer and CVD was equal.

Further, in adjusted competing risk modeling, the team noted PCE risk of ≥20% compared to a PCE risk of <7.5%.

In this analysis, they found an association with greater risk of both CVD (7.18; 95% CI, 5.77 – 8.94) and cancer (3.59; 95% CI, 2.91 – 4.43).

Conclusion

In summary, the team found the results demonstrated a clinical utility of PCE in risk stratification of both CVD and cancer.

They noted the data show higher incidence of cancer observed with PCE of <7.2%, while higher PCE led to increased risk of incident CVD. However, the team found absolute event risk was low for both at PCE of <7.5%.

“Further research is needed to understand how the treatment of shared modifiable risk factors via currently available and novel CVD therapies may reduce the morbidity and mortality from both CVD and cancer,” investigators wrote.

The study, “Pooled Cohort Equations and the competing risk of cardiovascular disease versus cancer: Multi-Ethnic Study of Atherosclerosis,” was published online in the American Journal of Preventive Cardiology.