High-Intensity Interval Training Versus Moderate Continuous Training in Patients With Heart Failure With Preserved Ejection Fraction: A Systematic Review and Meta-analysis.

High-intensity interval training (HIIT) is a novel training approach that improves cardiopulmonary fitness and functional capacity in numerous chronic conditions, however its impact in patients with heart failure (HF) with preserved ejection fraction (HFpEF) is uncertain. We evaluated data from prior studies reporting the effects of HIIT versus moderate continuous training (MCT), on cardiopulmonary exercise outcomes in patients with HFpEF. PubMed and SCOPUS were queried from inception till February 1st, 2022 for all randomized controlled trials (RCT) comparing the effect of HIIT versus MCT in patients with HFpEF on peak oxygen consumption (peak VO2), left atrial volume index (LAVI), respiratory exchange ratio (RER), and ventilatory efficiency (VE/CO2 slope). A random-effects model was applied, and the weighted mean difference (WMD) of each outcome was reported with 95% confidence intervals (CI). Three RCTs (total N = 150 patients with HFpEF), with a follow-up of 4 to 52 weeks were included in our analysis. Our pooled analysis demonstrated that HIIT significantly improved peak VO2 (WMD = 1.46 mL/kg/min (0.88, 2.05); P < 0.00001; I2 = 0%), as compared to MCT. However, no statistically significant change was demonstrated for LAVI (WMD = -1.71 mL/m2 (-5.58, 2.17); P = 0.39; I2 = 22%), RER (WMD = -0.10 (-0.32, 0.12); P = 0.38; I2 = 0%), and VE/CO2 slope (WMD = 0.62 (-1.99, 3.24); P = 0.64; I2 = 67%) in patients with HFpEF. Across current RCT data, HIIT, compared to MCT, had a significant impact on improving peak VO2. Conversely, there was no significant change in LAVI, RER, and VE/CO2 slope between HFpEF patients undertaking HIIT as opposed to MCT.

Linear fractional charge behavior in density functional theory through dielectric tuning of conductor-like polarizable continuum model.

A property of exact density functional theory is linear fractional charge behavior as electrons are added or removed from a molecule. Typical density functional approximations (DFAs) exhibit delocalization error, which overstabilizes this fractional charge. Conversely, solvent corrections have been shown to erroneously destabilize this fractional charge. This work will show that an implicit solvent correction with a tuned dielectric can be used as an ad hoc correction to offset the delocalizing character of DFAs and achieve linear fractional charge behavior. While desirable, in principle, we find that this linear charge behavior degrades the vertical ionization energies reported by DFAs. Our results reveal that the localizing character of the solvent correction and the Hartree-Fock (HF) exchange offset each other. This helps explain the decreased ratios of HF exchange to DFA exchange in long-range hybrid tuning studies that use a solvent correction.