Risk of COVID-19 infection after cardiac electrophysiology procedures.

BACKGROUND: During the COVID-19 pandemic, attempts to conserve resources and limit virus spread have resulted in delay of nonemergent procedures across all medical specialties, including cardiac electrophysiology (EP). Many patients have delayed care and continue to express concerns about potential nosocomial spread of coronavirus. OBJECTIVE: To quantify risk of development of COVID-19 owing to in-hospital transmission related to an EP procedure, in the setting of preventive measures instituted in our laboratory areas. METHODS: We contacted patients by telephone who underwent emergent procedures in the electrophysiology lab during the COVID-19 surge at our hospital (March 16, 2020, to May 15, 2020, reaching daily census 450 COVID-19 patients,) ≥2 weeks after the procedure, to assess for symptoms of and/or testing for COVID-19, and assessed outcomes from medical record review. RESULTS: Of the 124 patients undergoing EP procedures in this period, none had developed documented or suspected coronavirus infection. Seven patients described symptoms of chest pain, dyspnea, or fever; 3 were tested for coronavirus and found to be negative. Of the remaining 4, 2 had a more plausible alternative explanation for the symptoms, and 2 had transient symptoms not meeting published criteria for probable COVID-19 infection. CONCLUSION: Despite a high hospital census of COVID-19 patients during the period of hospital stay for an EP procedure, there were no likely COVID-19 infections occurring in follow-up of at least 2 weeks. With proper use of preventive measures as recommended by published guidelines, the risk of nosocomial spread of COVID-19 to patients in the EP lab is low.

Enhanced electrocardiographic monitoring of patients with Coronavirus Disease 2019.

Background: Many of the drugs being used in the treatment of the ongoing pandemic coronavirus disease 2019 (COVID-19) are associated with QT prolongation. Expert guidance supports electrocardiographic (ECG) monitoring to optimize patient safety. Objective: The purpose of this study was to establish an enhanced process for ECG monitoring of patients being treated for COVID-19. Methods: We created a Situation Background Assessment Recommendation tool identifying the indication for ECGs in patients with COVID-19 and tagged these ECGs to ensure prompt over reading and identification of those with QT prolongation (corrected QT interval > 470 ms for QRS duration ≤ 120 ms; corrected QT interval > 500 ms for QRS duration > 120 ms). This triggered a phone call from the electrophysiology service to the primary team to provide management guidance and a formal consultation if requested. Results: During a 2-week period, we reviewed 2006 ECGs, corresponding to 524 unique patients, of whom 103 (19.7%) met the Situation Background Assessment Recommendation tool-defined criteria for QT prolongation. Compared with those without QT prolongation, these patients were more often in the intensive care unit (60 [58.3%] vs 149 [35.4%]) and more likely to be intubated (32 [31.1%] vs 76 [18.1%]). Fifty patients with QT prolongation (48.5%) had electrolyte abnormalities, 98 (95.1%) were on COVID-19-related QT-prolonging medications, and 62 (60.2%) were on 1-4 additional non-COVID-19-related QT-prolonging drugs. Electrophysiology recommendations were given to limit modifiable risk factors. No patient developed torsades de pointes. Conclusion: This process functioned efficiently, identified a high percentage of patients with QT prolongation, and led to relevant interventions. Arrhythmias were rare. No patient developed torsades de pointes.

Enhanced CHO Clone Screening: Application of Targeted Locus Amplification and Next-Generation Sequencing Technologies for Cell Line Development.

Early analytical clone screening is important during Chinese hamster ovary (CHO) cell line development of biotherapeutic proteins to select a clonally derived cell line with most favorable stability and product quality. Sensitive sequence confirmation methods using mass spectrometry have limitations in throughput and turnaround time. Next-generation sequencing (NGS) technologies emerged as alternatives for CHO clone analytics. We report an efficient NGS workflow applying the targeted locus amplification (TLA) strategy for genomic screening of antibody expressing CHO clones. In contrast to previously reported RNA sequencing approaches, TLA allows for targeted sequencing of genomic integrated transgenic DNA without prior locus information, robust detection of single-nucleotide variants (SNVs) and transgenic rearrangements. During clone selection, TLA/NGS revealed CHO clones with high-level SNVs within the antibody gene and we report in another case the utility of TLA/NGS to identify rearrangements at transgenic DNA level. We also determined detection limits for SNVs calling and the potential to identify clone contaminations by TLA/NGS. TLA/NGS also allows to identify genetically identical clones. In summary, we demonstrate that TLA/NGS is a robust screening method useful for routine clone analytics during cell line development with the potential to process up to 24 CHO clones in less than 7 workdays.

Rapid and multi-level characterization of trastuzumab using sheathless capillary electrophoresis-tandem mass spectrometry.

Monoclonal antibodies (mAbs) are highly complex proteins that display a wide range of microheterogeneity that requires multiple analytical methods for full structure assessment and quality control. As a consequence, the characterization of mAbs on different levels is particularly product - and time - consuming. This work presents the characterization of trastuzumab sequence using sheathless capillary electrophoresis (referred as CESI) - tandem mass spectrometry (CESI-MS/MS). Using this bottom-up proteomic-like approach, CESI-MS/MS provided 100% sequence coverage for both heavy and light chain via peptide fragment fingerprinting (PFF) identification. The result was accomplished in a single shot, corresponding to the analysis of 100 fmoles of digest. The same analysis also enabled precise characterization of the post-translational hot spots of trastuzumab, used as a representative widely marketed therapeutic mAb, including the structural confirmation of the five major N-glycoforms.