Study population and Data Available
During the COVID-19 pandemic, Italian hospitals have been forced to adapt and to restructure their organization to cope with this urgent new critical situation.
As patients’ office visits were discouraged and many outpatient clinics were temporarily closed, alternative solutions, such as remote telematic health visits and telemonitoring (RM) have been adopted or implemented in order to focus on selected “high risk” patients in need of closer surveillance, as recommended by HRS Expert Consensus Statement and, more specifically, by Italian Arrhythmology and Cardiac Stimulation Society (AIAC). 5,6
RM provides the automated transmission of data based on prespecified alerts related to device function and clinical events. This allows rapid detection of abnormal device function and/or arrhythmia events. RM of these devices allows the transfer of the information stored in the implantable device so that it can be accessed by the clinic personnel via a secured website.
By this tool, we analysed a large cohort of remotely monitored ICD and CRT-D recipients, who had undergone device implantation before January 1st, 2019 at 7 Hospitals of Campania Region, comparing the arrhythmias incidence of the lockdown to the arrhythmias rate of the corresponding period in 2019. In total, 574 patients were initially selected in a retrospective fashion for this multicentre and observational study. All patients enrolled had been implanted according to European Society of Cardiology/European Heart Rhythm Association guidelines criteria for ICD/CRT-D implant, had received remote monitoring devices after signing a specific written informed consent for the utilization of their device data. Among all subjects under AICD and CRT-D remote monitoring at our hospitals, we selected 574 patients who had undergone AICD or CRT-D implant before 2019 and at least one office visit in the last 2 years and during the global observation period. None of the included patients was hospitalized due to COVID-19 infection or to acute respiratory distress.
Diagnosis of Arrhythmias and Device Programming
The devices of all patients selected for this study are equipped with reliable diagnostic algorithms that provide a series of alerts related to technical issues and to the occurrence of arrhythmic events. We focused on relevant cardiac arrhythmias including AF, ventricular tachycardia (VT) and ventricular fibrillation (VF). The diagnosis was initially made by the device via automatic detection and discrimination of episodes (AF/VT/VF); at second instance diagnosis was confirmed by an experienced physician via remote analysis of endocavitary strip received for each patient once or twice a week from January 2019 to May 2020, according to remote monitoring rules of each hospital involved in the research. Specifically, for all patients, we reviewed telemetry logs and confirmed the diagnosis of arrhythmias detected by device. Among all arrhythmias recorded by device, the ones analysed included incident VT, VF and new-onset AF. Out of these, we examined exclusively the ones that required device intervention: switch mode in the case of AF, life-saving therapy as anti-tachycardia pacing (ATP) and/or shock therapy in other cases. For AF count, in addition to device intervention, episodes with a duration of at least six hours and a cardiac rate above 220 beats per minute threshold were considered.
Subjects with permanent AF were excluded from the AF analysis.
Patients were excluded from the analysis if during follow-up they experienced hospital admission for: VT or AF ablation procedure, trans-catheter aortic valve implantation, mitral clip implantation.
At implant and at in-office evaluations (pre-lockdown) specific recommendations for device programming according to patient profile had been adopted, thus minimizing troubleshooting during follow up7. In particular, both standardized and conventional and tailored device programming was adopted to guarantee efficacy and safety of the therapy. All patients implanted for primary prevention have shown as first therapy three attempts of ATP for VT zone (from 180 to 200-220 bpm) and a sequence of ATP during capacitor charging for VF zone (>200-220 bmp); long detection time (intervals or cycles) in any window (setting depends on manufacturer’s device); shocks always delivered at the maximum energy (at least 30 J) in VT and VF zone; and the use of discrimination criteria for VT zone up to 200-220 bpm. Among patients implanted for secondary intervention, the 65% of cases has received a specific “MADIT-RIT” programming: therapies only for high heart rates (> 200 bpm, VF zone).8,9 In these patients a “tailored” programming approach was adopted through the knowledge of arrhythmic history, ECG morphology, cycle length and patients’ tolerance, in order to cover all clinical arrhythmias efficiently. No Monitor zone were found in all the devices examined.