Background: Transcatheter mitral valve repair (TMVR) has shown to be a safe and effective treatment option for symptomatic severe mitral regurgitation (MR) in patients who are at prohibitive surgical risk. Whether age and comorbidities impact the inpatient safety outcomes of TMVR versus surgical mitral valve repair (SMVR) is unknown.Methods: Using the national inpatient sample, patients undergoing either elective TMVR or SMVR between 2012 and 2015 were analyzed. Logistic, generalized logistic, and linear regression were used to compare inpatient complications, discharge disposition, and length of stay (LOS). Heterogeneity in the effect of TMVR versus SMVR across Charlson comorbidity index (CCI, categorized as <2 and ≥2) and age (categorized as <75 years old and ≥75 years old) were assessed for effect modification.Results: Overall, 8,716 hospitalizations were included, 7,950 (91%) SMVR and 766 (9%) TMVR. Compared with SMVR, patients undergoing TMVR were older (median age 79 vs. 62 years) and more likely to be female (45% vs. 40%) with a higher CCI score (median CCI 2 vs. 1). Despite being older with a higher comorbidity burden, patients undergoing TMVR had a lower incidence of permanent pacemaker implantation (OR 0.23, 95% CI: 0.11, 0.50), cerebrovascular accidents (OR 0.37, 95% CI: 0.15, 0.92), and major bleeding (OR 0.39, 95% CI: 0.32, 0.47). TMVR patients were also discharged 3 days earlier (CIE −3.26; 95% CI: −3.72, −2.80) and were less likely to be discharged to a skilled nursing facility (OR 0.72, 95% CI 0.55, 0.93). Additionally, the relative reduction in complications after TMVR versus SMVR was significantly higher in older (age ≥75 years) and more comorbid (CCI ≥2) patients (p for interaction <.05 for both). Conclusion:Patients treated with TMVR, as compared with SMVR, were older and had more comorbidities, but had a lower incidence of inpatient complications, shorter Abbreviations: CCI, Charlson comorbidity index; LOS, length of stay; MR, mitral regurgitation; NIS, national inpatient sample; PPM, permanent pacemaker implantation; SMVR, surgical mitral valve repair; TMVR, transcatheter mitral valve repair.Hanumantha R. Jogu and Sameer Arora have contributed equally to this article.

Background: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs). Methods: LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during 'daytime' when induction of anaesthesia was between 8:00 AM and 7:59 PM, and as 'night-time' when induction was between 8:00 PM and 7:59 AM. Results: Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P¼0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P¼0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P¼0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09e1.90; P¼0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89e1.90; P¼0.15). Conclusions: Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events. Clinical trial registration: NCT01601223.

Protein oxidation by reactive oxygen species is known to result in changes in the structure and function of the oxidized protein. Many proteins can tolerate multiple oxidation events before altering their conformation, while others suffer gross changes in conformation after a single oxidation event. Additionally, reactive oxygen species have been used in conjunction with mass spectrometry to map the accessible surface of proteins, often after verification that the oxidations do not alter the conformation. However, detection of oxidation-induced conformational changes by detailed kinetic oxidation analysis of individual proteolytic peptides or non-mass spectrometric analysis is labor-intensive and often requires significant amounts of sample. In this work, we describe a methodology to detect oxidation-induced conformational changes in proteins via direct analysis of the intact protein. The kinetics of addition of oxygen to unmodified protein are compared with the kinetics of addition of oxygen to the mono-oxidized protein. These changes in the rate of oxidation of the oxidized versus the non-oxidized protein are strongly correlated with increases in the random coil content as measured by the molar ellipticity at 198 nm. This methodology requires only small amounts of protein, and can be done rapidly without additional sample handling or derivatization.