Sex-specific risk scores help predict patients at the highest risk for death

A retrospective cohort study found that sex-specific prognostic risk scores were effective at estimating mortality in patients while undergoing exercise treadmill testing. The scores were most effective at identifying patients at the highest risk for death.

Lead researcher Paul C. Cremer, MD, of the Cleveland Clinic’s Heart and Vascular Institute, and colleagues published their results online Oct. 26 in JAMA Cardiology.

“In patients undergoing treadmill testing, our data support separate risk scores according to sex,” the researchers wrote. “Certain variables are present or absent in the models for men vs women, and the hazard ratios for risk factors common to both models differ according to sex. Therefore, rather than simply adjusting for sex, we argue that a sex-specific approach should be considered when assessing the prognosis for patients who undergo exercise testing.”

The researchers mentioned that the Duke Treadmill Score and the Lauer nomogram are two common tools used to assess prognosis and predict all-cause mortality in patients with known or suspected coronary artery disease.

For this analysis, the researchers developed sex-specific risk scores from a cohort of 60,895 patients at the Cleveland Clinic Foundation from 2000 to 2010. They also validated the scores in a group of 49,278 patients at the Henry Ford Hospital from Jan. 1, 1991 through Dec. 31, 2009. All of the patients were at least 18 years old and underwent exercise treadmill testing.

In the Cleveland Clinic cohort, 59.4 percent of patients were men and the median age was 54 years old. During a median follow-up period of seven years, 4.2 percent of patients died.

In the Henry Ford cohort, 52.5 percent of patients were men and the median age was 54 years old. During a median follow-up period of 10.2 years, 13.5 percent of patients died.

The C statistics for the sex-specific risk scores were higher when using the researchers’ scores (0.79 for women and 0.81 for men) than when using the Duke Treadmill Score (0.70 for women and 0.72 for men) or the Lauer nomogram (0.74 for women and 0.75 for men). The C statistics in the validation cohort were similar: 0.78 for women and 0.79 for men.

The researchers mentioned that decreased exercise capacity was the most important risk factor for men and women when assessing mortality.

They also noted the study had a few limitations, including they did not assess cardiac death and did not include imaging data in their analysis. In addition, patients underwent evaluation at large referral centers, so the results may not be generalizable to smaller hospitals. Further, the risk scores tested in the Cleveland Clinic and Henry Ford cohorts were similar but not identical.

The researchers added that they used the sex-specific risk scores and created an online calculator to estimate 10-year mortality.

“Even when accounting for multiple comorbidities, exercise capacity was still the predominant risk factor in men and women,” they wrote. “This online calculator can be used by physicians and patients to not only assess prognosis but also emphasize the importance of exercise, even in the presence of other cardiovascular risk factors.”