A Nonexercise Prediction of Peak Oxygen Uptake for Patients With Cardiovascular Disease

DATA FROM THE FITNESS REGISTRY AND THE IMPORTANCE OF EXERCISE INTERNATIONAL DATABASE (FRIEND)

Abstract

Purpose: 

Nonexercise predictions of peak oxygen uptake (V˙o_2peak) are used clinically, yet current equations were developed from cohorts of apparently healthy individuals and may not be applicable to individuals with cardiovascular disease (CVD). Our purpose was to develop a CVD-specific nonexercise prediction equation for V˙o_2peak.

Methods: 

Participants were from the Fitness Registry and Importance of Exercise International Database (FRIEND) with a diagnosis of coronary artery bypass surgery (CABG), myocardial infarction (MI), percutaneous coronary intervention (PCI), or heart failure (HF) who met maximal effort criteria during a cardiopulmonary exercise test (n = 15 997; 83% male; age 63.1 ± 10.4 yr). The cohort was split into development (n = 12 798) and validation groups (n = 3199). The prediction equation was developed using regression analysis and compared with a previous equation developed on a healthy cohort.

Results: 

Age, sex, height, weight, exercise mode, and CVD diagnosis were all significant predictors of V˙o_2peak. The regression equation was:

V˙o_2peak (mL · kg^–1 · min^–1) = 16.18 – (0.22 × age [yr]) + (3.63 × sex [male = 1; female = 0]) + (0.14 × height [cm]) – (0.12 × weight [kg]) + (3.62 × mode [treadmill = 1; cycle = 0]) – (2.70 × CABG [yes = 1, no = 0]) – (0.31 × MI [yes = 1, no = 0]) + (0.37 × PCI [yes = 1, no = 0]) – (4.47 × HF [yes = 1, no = 0]). Adjusted R² = 0.43; SEE = 4.75 mL · kg^–1 · min^–1.

Compared with measured V˙o_2peak in the validation group, percent predicted V˙o_2peak was 141% for the healthy cohort equation and 100% for the CVD-specific equation.

Conclusions: 

The new equation for individuals with CVD had lower error between measured and predicted V˙o_2peak than the healthy cohort equation, suggesting population-specific equations are needed for predicting V˙o_2peak; however, errors associated with nonexercise prediction equations suggest V˙o_2peak should be directly measured whenever feasible.

In Brief

This study developed a nonexercise prediction equation for peak oxygen uptake (Vo_2peak) in individuals with cardiovascular disease. The new equation provided a lower mean error between measured and predicted Vo_2peak than an equation developed from a healthy cohort highlighting the importance of using a population-specific equation when predicting Vo_2peak.