Cardiopulmonary exercise testing in the MRI environment yielded nearly identical maximal oxygen consumption compared to a standard lab (mean difference <3.40 ml/kg/min).
Cross-Sectional (n=10)
Does cardiopulmonary exercise testing in an MRI environment yield equivalent VO2max results compared to a standard exercise physiology lab in recreationally trained subjects?
Cardiopulmonary exercise testing can be effectively performed in the MRI environment, yielding equivalent VO2max results to standard labs and enabling immediate post-exercise cardiac imaging.
Effect estimate: Mean difference < 3.40 ml/kg/min (95% CI LCL 0.8182)
Maximal oxygen consumption (Formula: see textmax) measured by cardiopulmonary exercise testing (CPX) is the gold standard for assessment of cardiorespiratory fitness. Likewise, cardiovascular magnetic resonance (CMR) is the gold standard for quantification of cardiac function. The combination of CPX and CMR may offer unique insights into cardiopulmonary pathophysiology; however, the MRI-compatible equipment needed to combine these tests has not been available to date. We sought to determine whether CPX testing in the MRI environment, using equipment modified for MRI yields results equivalent to those obtained in standard exercise physiology (EP) lab. Ten recreationally trained subjects completed Formula: see textmax tests in different locations; an EP laboratory and an MRI laboratory, using site specific equipment. CMR cine images of the heart were acquired before and immediately after maximal exercise to measure cardiac function. Subjects in all tests met criteria indicating that peak exercise was achieved. Despite equipment modifications for the MRI environment, Formula: see textmax was nearly identical between tests run in the different labs (95% lower confidence limit (LCL) = 0.8182). The mean difference in Formula: see textmax was less than 3.40 ml (kg/min)(-1), within the variability expected for tests performed on different days, in different locations, using different metabolic carts. MRI performed at rest and following peak exercise stress indicated cardiac output increased from 5.1 ± 1.0 l min(-1) to 16.4 ± 5.6 l min(-1), LVEF increased from 65.2 ± 3.3% to 78.4 ± 4.8%, while RVEF increased from 52.8 ± 5.3% to 63.4 ± 5.3%. Regression analysis revealed a significant positive correlation between Formula: see textmax and stroke volume (R = 0.788, P = 0.006), while the correlation with cardiac output did not reach statistical significance (R = 0.505, P = 0.137). Formula: see textmax CPX testing can be effectively performed in the MRI environment, enabling direct combination of physiological data with advanced post-exercise imaging in the same test session.
LaFountain et al. (Thu,) conducted a cross-sectional in Healthy volunteers (n=10). Cardiopulmonary exercise testing (CPX) in the MRI environment vs. CPX testing in standard exercise physiology (EP) lab was evaluated on Maximal oxygen consumption (VO2max) (Mean difference < 3.40 ml/kg/min, 95% CI LCL 0.8182). Cardiopulmonary exercise testing in the MRI environment yielded nearly identical maximal oxygen consumption compared to a standard lab (mean difference <3.40 ml/kg/min).