Aims: The role of cardiopulmonary exercise testing (CPET) in predicting major adverse cardiovascular events (MACE) in people with congenital heart disease (ConHD) is unknown. A systematic review with meta-analysis was conducted to report the associations between CPET parameters and MACE in people with ConHD. Methods and results: Electronic databases were systematically searched on 30 April 2020 for eligible publications. Two authors independently screened publications for inclusion, extracted study data, and performed risk of bias assessment. Primary meta-analysis pooled univariate hazard ratios across studies. A total of 34 studies (18 335 participants; 26.2 ± 10.1 years; 54% ± 16% male) were pooled into a meta-analysis. More than 20 different CPET prognostic factors were reported across 6 ConHD types. Of the 34 studies included in the meta-analysis, 10 (29%), 23 (68%), and 1 (3%) were judged as a low, medium, and high risk of bias, respectively. Primary univariate meta-analysis showed consistent evidence that improved peak and submaximal CPET measures are associated with a reduce risk of MACE. This association was supported by a secondary meta-analysis of multivariate estimates and individual studies that could not be numerically pooled. Conclusion: Various maximal and submaximal CPET measures are prognostic of MACE across a variety of ConHD diagnoses. Further well-conducted prospective multicentre cohort studies are needed to confirm these findings.

Purpose: This study had 2 objectives: (1) to examine whether the validity of the supramaximal verification test for maximal oxygen uptake (V˙O2max) differs in children and adolescents when stratified for sex, body mass, and cardiorespiratory fitness and (2) to assess sensitivity and specificity of primary and secondary objective criteria from the incremental test to verify V˙O2max. Methods: In total, 128 children and adolescents (76 male and 52 females; age: 9.3–17.4 y) performed a ramp-incremental test to exhaustion on a cycle ergometer followed by a supramaximal test to verify V˙O2max. Results: Supramaximal tests verified V˙O2max in 88% of participants. Group incremental test peak V˙O2 was greater than the supramaximal test (2.27 [0.65] L·min−1 and 2.17 [0.63] L·min−1; P < .001), although both were correlated (r = .94; P < .001). No differences were found in V˙O2 plateau attainment or supramaximal test verification between sex, body mass, or cardiorespiratory fitness groups (all Ps > .18). Supramaximal ...

This is the first study to identify that acute improvements in peripheral vascular function following high-intensity interval exercise are not mirrored by improvements in cerebrovascular reactivity in healthy young adults. High-intensity interval exercise completed at both 75% and 90% V̇o_2max increased brachial artery flow-mediated dilation 1 and 3 h following exercise, compared with continuous moderate-intensity exercise and a sedentary control condition. By contrast, cerebrovascular reactivity was unchanged following all four conditions.

This is the first study to observe similar increases in cerebral blood flow during incremental exercise in adolescents and adults. Increases in cerebral blood flow during exercise were smaller in children compared with adolescents and adults and were associated with a greater V̇_E/V̇co₂ slope. This study also provides the first evidence on the progressive development of the regulatory role of end-tidal CO₂ on cerebral blood flow during exercise during the transition from childhood to adulthood.

The aim of this study was to compare the kinetic response of middle cerebral artery blood velocity (MCAv) to moderate- and heavy-intensity cycling in adults, and explore the relationship between maximal oxygen uptake (V̇o_2max) and MCAv kinetics. Seventeen healthy adults (23.8 ± 2.4 yr, 9 females) completed a ramp incremental test to exhaustion on a cycle ergometer to determine V̇o_2max and the gas exchange threshold (GET). Across six separate visits, participants completed three 6-min transitions at a moderate intensity (90% GET) and three at a heavy intensity (40% of the difference between GET and V̇o_2max). Bilateral MCAv was measured using transcranial Doppler (TCD) ultrasonography and analyzed using a monoexponential model with a time delay. The time constant (τ) of the MCAv response was not different between moderate- and heavy-intensity cycling (25 ± 10 vs. 26 ± 8 s, P = 0.82), as was the time delay (29 ± 11 vs. 29 ± 10 s, P = 0.95). The amplitude of the exponential increase in MCAv from baseline was greater during heavy-intensity cycling (23.9 ± 10.0 cm·s⁻¹, 34.1 ± 14.4%) compared with moderate-intensity cycling (12.7 ± 4.4 cm·s⁻¹, 18.7 ± 7.5%; P < 0.01). Following the exponential increase, a greater fall in MCAv was observed during heavy-intensity exercise compared with moderate-intensity exercise (9.5 ± 6.9 vs. 2.8 ± 3.8 cm·s⁻¹, P < 0.01). MCAv after 6 min of exercise remained elevated during heavy-intensity exercise compared with moderate-intensity exercise (85.2 ± 9.6 vs. 79.3 ± 7.7 cm·s⁻¹, P ≤ 0.01). V̇o_2max was not correlated with MCAv τ or amplitude (r = 0.11–0.26, P > 0.05). These data suggest that the intensity of constant-work rate exercise influences the amplitude, but not time-based, response parameters of MCAv in healthy adults, and found no relationship between cardiorespiratory fitness and MCAv kinetics. NEW & NOTEWORTHY This is the first study to model the MCAv kinetic response to moderate- and heavy-intensity cycling in healthy adults. This study found that the amplitude of the exponential rise in MCAv at exercise onset was greater during heavy-intensity exercise (∼34%) compared with moderate-intensity exercise (∼19%), but the time-based characteristics of the responses were similar between intensities. Higher cardiorespiratory fitness was not associated with a greater or faster MCAv response to moderate- or heavy-intensity exercise.

Purpose: Cerebrovascular reactivity (CVR) is impaired in adolescents with cardiovascular disease risk factors. A breath‐hold test is a noninvasive method of assessing CVR, yet there are no reliability data of this outcome in youth. This study aimed to assess the reliability of a breath‐hold protocol to measure CVR in adolescents.Methods: Twenty‐one 13 to 15 year old adolescents visited the laboratory on two separate occasions, to assess the within‐test, within‐day and between‐day reliability of a breath‐hold protocol, consisting of three breath‐hold attempts. CVR was defined as the relative increase from baseline in middle cerebral artery mean blood velocity following a maximal breath‐hold of up to 30 seconds, quantified via transcranial Doppler ultrasonography.Results: Mean breath‐hold duration and CVR were never significantly correlated (r< .31,P> .08). The within‐test coefficient of variation for CVR was 15.2%, with no significant differences across breath‐holds (P= .88), so the three breath‐hold attempts were averaged for subsequent analyses. The within‐ and between‐day coefficients of variation for CVR were 10.8% and 15.3%, respectively.Conclusions: CVR assessed via a three breath‐hold protocol can be reliably measured in adolescents, yielding similar within‐ and between‐day reliability. Analyses revealed that breath‐hold length and CVR were unrelated, indicating the commonly reported normalization of CVR to breath‐hold duration (breath‐hold index) may be unnecessary in youth.