Obesity and its impact on functional capacity: understanding the interplay for health management

Abstract Background Cardiopulmonary exercise testing (CPET) plays a significant role in evaluating obese individuals due to the unique physiological challenges they face during exercise. As diastolic function is impaired in majority of morbidly obese pts, combination of CPET with diastolic stress echocardiography may add more information to objective assessment Objective To assess the value of combined stress echo CPET (ESE-CPET) in assessment of diastolic function in morbidly obese pts. Methods We studied 400 pts (74% female, age 39.2±9.9 years) referred for bariatric surgery. Echocardiographic measurements have been performed before CPET and immediately after the test. CPET was performed on treadmill (maximal Bruce) with breath-by-breath gas analysis. We measured both peak oxygen consumption (peakVO2) and VO2 at anaerobic threshold (AT), as well as other ventilatory and hemodynamic parameters. Results Mean BMI was 44± kg/m2. Left ventricular ejection fraction was 63.5±5.6%. Mean VO2 at AT was 17±2 ml/kg/min, mean Peak VO2 was 19±4 ml/kg/min. Resting eho : mitral E to A wave (E/A),deceleration time ( Dt) and mitral E to mitral anular E’ (E/E’) values did not correlate significantly with parameters of CPET. However, there was significant correlation between maximal E/ E’ with PeakVO2 and VO2 at AT (p<0.001), , Pet CO2 (p=0.0001) as well as with myocardial performance index as a parameter of global left ventricular function (p<0.001) However, VE/VCO2 was the strongest predictor of increase in E/ E’≥ 15 indicating the importance of ventilatory parameters and dynamic tests. Conclusions Assessment of diastolic function in morbid obese patients represents a great challenge to cardiologists because obesity contributed significantly to deterioration of diastolic function. Combined stress echo CPET showed the advantage and benefit of integrated evaluation of both pulmonary and cardiovascular function representing as a significant step forward in assessment of diastolic function overcoming the limitations of resting echocardiography and CPET performed as a single test.