Diagnostic evaluation and cardiopulmonary exercise test findings in young athletes with persistent symptoms following COVID-19.

OBJECTIVES: Persistent or late-onset cardiopulmonary symptoms following COVID-19 may occur in athletes despite a benign initial course. We examined the yield of cardiac evaluation, including cardiopulmonary exercise testing (CPET), in athletes with cardiopulmonary symptoms after COVID-19, compared CPETs in these athletes and those without COVID-19 and evaluated longitudinal changes in CPET with improvement in symptoms. METHODS: This prospective cohort study evaluated young (18-35 years old) athletes referred for cardiopulmonary symptoms that were present>28 days from COVID-19 diagnosis. CPET findings in post-COVID athletes were compared with a matched reference group of healthy athletes without COVID-19. Post-COVID athletes underwent repeat CPET between 3 and 6 months after initial evaluation. RESULTS: Twenty-one consecutive post-COVID athletes with cardiopulmonary symptoms (21.9±3.9 years old, 43% female) were evaluated 3.0±2.1 months after diagnosis. No athlete had active inflammatory heart disease. CPET reproduced presenting symptoms in 86%. Compared with reference athletes (n=42), there was similar peak VO2 but a higher prevalence of abnormal spirometry (42%) and low breathing reserve (42%). Thirteen athletes (62%) completed longitudinal follow-up (4.8±1.9 months). The majority (69%) had reduction in cardiopulmonary symptoms, accompanied by improvement in peak VO2 and oxygen pulse, and reduction in resting and peak heart rate (all p<0.05). CONCLUSION: Despite a high burden of cardiopulmonary symptoms after COVID-19, no athlete had active inflammatory heart disease. CPET was clinically useful to reproduce symptoms with either normal testing or identification of abnormal spirometry as a potential therapeutic target. Improvement in post-COVID symptoms was accompanied by improvements in CPET parameters.

Sex-Based Differences in Peak Exercise Blood Pressure Indexed to Oxygen Consumption Among Competitive Athletes.

PURPOSE: Although exercise testing guidelines define cutoffs for an exaggerated exercise systolic blood pressure (SBP) response, SBPs above these cutoffs are not uncommon in athletes given their high exercise capacity. Alternately, guidelines also specify a normal SBP response that accounts for metabolic equivalents (METs; mean [SD] of 10 [2] mm Hg per MET or 3.5 mL/kg/min oxygen consumption [V˙o2]). SBP and V˙o2 increase less during exercise in females than males. It is not clear if sex-based differences in exercise SBP are related to differences in V˙o2 or if current recommendations for normal increase in SBP per MET produce reasonable estimates using measured METs (ie, V˙o2) in athletes. We therefore examined sex-based differences in exercise SBP indexed to V˙o2 in athletes with the goal of defining normative values for exercise SBP that account for fitness and sex. METHODS: Using prospectively collected data from a single sports cardiology program, normotensive athlete patients were identified who had no relevant cardiopulmonary disease and had undergone cardiopulmonary exercise testing with cycle ergometry or treadmill. The relationship between ΔSBP (peak - rest) and ΔV˙o2 (peak - rest) was examined in the total cohort and compared between sexes. FINDINGS: A total of 413 athletes (mean [SD] age, 35.5 [14] years; 38% female; mean [SD] peak V˙o2, 46.0 [10.2] mL/kg/min, 127% [27%] predicted) met the inclusion criteria. The ΔSBP correlated with unadjusted ΔV˙o2 (cycle: R2 = 0.18, treadmill: R2 = 0.12; P < 0.0001). Female athletes had lower mean (SD) peak SBP (cycle: 161 [15] vs 186 [24] mm Hg; treadmill: 165 [17] vs 180 [20] mm Hg; P < 0.05) than male athletes. Despite lower peak SBP, mean (SD) ΔSBP relative to unadjusted ΔV˙o2 was higher in female than male athletes (cycle: 25.6 [7.2] vs 21.1 [7.3] mm Hg/L/min; treadmill: 21.6 [7.2] vs 17.0 [6.2] mm Hg/L/min; P < 0.05). When V˙o2 was adjusted for body size and converted to METs, female and male athletes had similar mean (SD) ΔSBP /ΔMET (cycle: 6.0 [2.1] vs 5.8 [2.0] mm Hg/mL/kg/min; treadmill: 4.7 [1.8] vs 4.8 [1.7] mm Hg/mL/kg/min). IMPLICATIONS: In this cohort of athletes without known cardiopulmonary disease, observed sex-based differences in peak exercise SBP were in part related to the differences in ΔV˙o2 between male and female athletes. Despite lower peak SBP, ΔSBP/unadjusted ΔV˙o2 was paradoxically higher in female athletes. Future work should define whether this finding reflects sex-based differences in the peripheral vascular response to exercise. In this athletic cohort, ΔSBP/ΔMET was similar between sexes and much lower than the ratio that has been proposed by guidelines to define a normal SBP response. Our observed ΔSBP/ΔMET, based on measured rather than estimated METs, provides a clinically useful estimate for normal peak SBP range in athletes.

Cardiopulmonary Exercise Testing in Athletes: Expect the Unexpected.

Purpose of Review: Cardiopulmonary exercise testing (CPET) is a tool designed to assess the integrated function of the cardiac, pulmonary, vascular and musculoskeletal systems to produce an exercise effort. CPET may be performed for performance purposes as part of optimizing a training program or for clinical purposes in athletes with established cardiovascular disease or in those with symptoms suggestive of cardiopulmonary pathology. Most normative values used for CPET parameters have been derived in the general population, in whom there will be expected differences in exercise physiology as compared to a trained athlete. In this review, our goal is to examine current available data on expected findings on CPET in athletes, highlight how these differ from the general population-derived normative values, and identify areas in need of further research to optimize the application of CPET in athletes. Recent Findings: Athletes demonstrate differences in exercise hemodynamic and gas exchange profiles as compared to non-athletes including: higher cardiac output, faster heart rate recovery, higher peak V̇O2, higher prevalence of exercise-induced arterial hypoxemia, and lower breathing reserve. Summary: CPET is an important tool to optimize performance and assess for underlying pathology in an athletic population. The impact of routine, vigorous physical activity on exercise physiology should be integrated into determination of what constitutes a normal CPET result in an athletic individual.

Utility of the oxygen pulse in the diagnosis of obstructive coronary artery disease in physically fit patients.

Cardiopulmonary exercise testing (CPET) guidelines recommend analysis of the oxygen (O2 ) pulse for a late exercise plateau in evaluation for obstructive coronary artery disease (OCAD). However, whether this O2 pulse trajectory is within the range of normal has been debated, and the diagnostic performance of the O2 pulse for OCAD in physically fit individuals, in whom V˙O2 may be more likely to plateau, has not been evaluated. Using prospectively collected data from a sports cardiology program, patients were identified who were free of other cardiac disease and underwent clinically-indicated CPET within 90 days of invasive or computed tomography coronary angiography. The diagnostic performance of quantitative O2 pulse metrics (late exercise slope, proportional change in slope during late exercise) and qualitative assessment for O2 pulse plateau to predict OCAD was assessed. Among 104 patients (age:56 ± 12 years, 30% female, peak V˙O2 119 ± 34% predicted), the diagnostic performance for OCAD (n = 24,23%) was poor for both quantitative and qualitative metrics reflecting an O2 pulse plateau (late exercise slope: AUC = 0.55, sensitivity = 68%, specificity = 41%; proportional change in slope: AUC = 0.55, sensitivity = 91%, specificity = 18%; visual plateau/decline: AUC = 0.51, sensitivity = 33%, specificity = 67%). When O2 pulse parameters were added to the electrocardiogram, the change in AUC was minimal (-0.01 to +0.02, p ≥ 0.05). Those patients without OCAD with a plateau or decline in O2 pulse were fitter than those with linear augmentation (peak V˙O2 133 ± 31% vs. 114 ± 36% predicted, p < 0.05) and had a longer exercise ramp time (9.5 ± 3.2 vs. 8.0 ± 2.5 min, p < 0.05). Overall, a plateau in O2 pulse was not a useful predictor of OCAD in a physically fit population, indicating that the O2 pulse should be integrated with other CPET parameters and may reflect a physiologic limitation of stroke volume and/or O2 extraction during intense exercise.