A heart-team hybrid approach for atrial fibrillation: a single-centre long-term clinical outcome cohort study.

OBJECTIVES: The Cox-maze IV is the gold standard for surgical ablation of atrial fibrillation (AF). A heart-team hybrid approach using selected epicardial thoracoscopic surgical ablations and completion endocardial ablations to replicate the Cox-maze IV lesion set has gained popularity and early results have been promising. We herein report our single-centre long-term clinical outcomes using the heart-team hybrid approach with 455 patients. METHODS: From 1 March 2013 to 1 July 2019, we prospectively collected data on all patients referred to our heart team for rhythm-control strategy for AF. Baseline characteristics, procedural complications and long-term freedom from AF (FFAF) both on and off anti-arrhythmic drug therapy were analysed. Ambulatory monitoring (>7 days) was obtained at 3 months and annually thereafter. RESULTS: Four hundred and fifty-five patients completed the hybrid approach. Four hundred and forty-five (97.8%) patients had non-paroxysmal AF (long-standing persistent AF n = 249, 54.7%; persistent AF n = 196, 43.1%; paroxysmal AF n = 10, 2.2%). Average duration of AF was 5.9 ± 6.1 years. Average left atrial diameter was 4.8 ± 0.8 cm. FFAF at 3, 12, 24 and 36 months was 92%, 87%, 81% and 72%, respectively. FFAF without the use of anti-arrhythmic medications was 75%, 81%, 76% and 66%. Any surgical complications occurred in 28 (6.1%) patients. CONCLUSIONS: A heart-team hybrid strategy for the treatment of AF is safe and effective. In a predominantly non-paroxysmal population with AF, at the 3-year follow-up, FFAF in patients on and off anti-arrhythmic drugs approaches that of patients who had the Cox-maze IV.

Quantification of immunoreactive viral influenza proteins by immunoaffinity capture and isotope-dilution liquid chromatography-tandem mass spectrometry.

An immunocapture isotope dilution mass spectrometry (IC-IDMS) method was developed to quantify antibody-bound influenza hemagglutinins (HA) in trivalent influenza vaccines (TIV). Currently, regulatory potency requirements for TIV require HA quantification based on the single radial immunodiffusion (SRID) assay, which is time-consuming, laborious, and requires production of large quantities of reagents globally. In IC-IDMS, antiserum to the HA of interest captured viral proteins that were in the correct conformation to be recognized by the antibodies. The captured proteins were digested, and evolutionarily conserved tryptic peptides were quantified using isotope-dilution liquid chromatography-tandem mass spectrometry. IC-IDMS relies on antibody-antigen binding similar to SRID but incorporates the accuracy and precision of IDMS. Polyclonal antibodies (pAb-H3) prepared by injection of sheep with purified H3 HA captured 82.9% (55.26 fmol/µL) of the total H3 HA (66.69 fmol/µL) from the commercial TIV and 93.6% (57.23 fmol/µL) of the total H3 HA (61.14 fmol/µL) in purified virus. While other HA (H1, B), neuraminidase (N1, N2, NB), viral matrix proteins, and nucleoproteins were also captured by this antiserum, our results were not affected due to the specificity of the mass spectrometer. IC-IDMS is an accurate, precise, sensitive, and selective method to measure antibody-bound HA in purified virus and commercial vaccines.