The primary prevention implantable cardioverter-defibrillator (ICD) during the COVID-19 pandemic

Br J Cardiol 2021;28:54doi:10.5837/bjc.2021.021 Leave a comment
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First published online 22nd April 2021

During the recent ‘first wave’ of the COVID-19 pandemic, the National Health Service (NHS) has triaged planned services to create surge capacity. The primary prevention implantable cardioverter-defibrillator (ICD) was in a grey area of triage guidance, but it was suggested as a procedure that could be reasonably stopped. Recent reports have highlighted deaths of patients awaiting ICDs who may have been deferred during the pandemic. In our trust we reorganised our device service and continued to implant primary prevention ICDs during the ‘first wave’ and, here, report that most patients wished to proceed and underwent uncomplicated implantations. One patient later died from COVID-19, although the transmission site cannot be definitively concluded. With strict adherence to public health guidance and infection prevention strategies, we believe that ICD implantation can be performed safely during the pandemic, and this should be standard practice during subsequent surges.


During the COVID-19 pandemic, difficult decisions have had to be made about access to a wide range of therapies and procedures. On 17 March 2020, National Health Service (NHS) bodies were instructed to create capacity to manage an expected surge of COVID-19 cases, and this included stopping all elective procedures by 15 April.1 Guidelines for triage of patients left those awaiting a primary prevention implantable cardioverter-defibrillator (ICD) in a grey area: a case-by-case decision should be made, but that these procedures could be reasonably delayed.2

It has recently been highlighted that patients awaiting a primary prevention ICD have in many cases had their procedures deferred, and deaths among this patient group have been reported.3 Following this, strong calls have been made that this procedure should be prioritised during future waves of COVID-19 hospital admissions. We wish to add our experience from the ‘first wave’ to provide reassurance that this is a justified approach.


Following the NHS request on 17 March 2020, two consultant cardiologists undertook triage of all patients awaiting device procedures in our tertiary cardiac unit. When appropriate, remote consultation with the patient was undertaken to agree the appropriate triage strategy. Our catheter lab timetable was revised to permit a device list to run Monday to Friday, with reduced capacity to ensure appropriate infection prevention measures could be employed. We continued to assess and triage new referrals and made neighbouring implanting centres aware of our processes so that their patients could be taken on when necessary. Here, we report the strategy adopted for patients awaiting a primary prevention ICD, as well as reviewing the cases performed during the first wave of the COVID-19 pandemic, up to six weeks following the initial request to restore cardiac services on 29 April.4


On 17 March 2020 we had 22 patients on our waiting list for a primary prevention ICD: 15 of these in association with cardiac resynchronisation therapy (CRT-D), and four for a subcutaneous defibrillator (SICD). On initial triage it was felt two of the planned CRT-D procedures should be deferred, given evidence of improvement in left ventricular ejection fraction in one case, and reduction in QRS width in another, on medical therapy. One patient was deferred after a new significant condition was identified requiring more urgent investigation and therapy, and one patient decided they no longer wished to proceed with an ICD implant. The other 18 patients (82% of those on waiting list) were deemed appropriate to proceed with urgent implantation, and in only one of these cases did a patient, with significant conditions requiring shielding, request to wait until routine services resumed.

At the end of April, when plans to restore cardiac activity were requested, 145 beds in our hospital were caring for COVID-19 patients, of an approximately 750-bed capacity. This represented the peak of the first wave and this number did not reduce significantly until June. The usual intensive-care capacity was more than doubled to accommodate patients requiring ventilation, and this included the use of beds in the cardiothoracic wards.

Of 37 ICDs implanted in our centre between 17 April and 10 June, 24 (65%) were new primary prevention devices. One patient developed symptoms 10 days post-implant and was diagnosed with COVID-19, unfortunately dying 15 days post-implantation of a CRT-D. Review of this admission showed no evidence of breach in recommended personal protective equipment (PPE) use, or exposure to coronavirus while in hospital. They did have several contacts with coronavirus-positive individuals in the community. The Public Health England (PHE) guidance at that point did not advocate screening asymptomatic patients pre-admission or staff, and, ultimately, it is not possible to be certain when they contracted the virus. All other patients have been assessed at a routine first device check and no complications from these implants have occurred. We recorded no deaths on our waiting list pre-procedure.


The National Institute for Cardiovascular Outcomes Research (NICOR) have recently reported that, at the peak of the first wave of the COVID-19 pandemic, the number of ICD implants was 67% lower than a year earlier.5 This suggests that the vast majority of primary prevention implants had been suspended. Alongside the individual centre reports of deaths on the waiting lists for ICD implantation,3 this NICOR report also highlights an increase in the number of out-of-hospital cardiac arrest patients observed during the pandemic.5 We do not yet have detailed understanding of the excess mortality observed in the UK during the first wave, but this observation suggests a significant increase in cardiac arrest over that period, and it is possible a proportion of this may have been preventable if usual cardiac activity was occurring. There are several signals that delaying primary prevention ICD implantation may be harmful, although this is currently not quantifiable.

Although we only report a single-centre experience, it has shown that primary prevention ICDs can be implanted with appropriate triage during the COVID-19 pandemic. In our centre, we saw significant impact from COVID-19, including the use of cardiac intensive-care beds for COVID-19 patients, and reorganisation of services, including cardiologists looking after general medical admissions, but felt that we needed to maintain a safe specialist service for our device population. Although the population awaiting ICD implantation will be expected to carry high risk of a poor outcome if they contract COVID-19, it is important to remember that they are at higher risk of sudden death generally. The reports of deaths on waiting lists reinforce this message. It is well reported that people have been reluctant to seek medical care during the pandemic, but we surprisingly found most patients remained keen to proceed with their procedure, suggesting patients do perceive significant value in the recommended therapy.

During this period, PHE guidance did evolve, but throughout we aimed to minimise the risk to patients by: all staff wearing masks, minimising contact, limiting catheter lab staff and having experienced single operators (i.e. non-training), discharging patients as soon as possible and avoiding mixing with non-elective patient areas. Subsequently, significant improvements have been made to systems, including the creation of COVID-secure areas, pathways for routine staff screening for coronavirus antigen, and routine screening and self-isolation of elective patients. In future surges of COVID, these measures should further minimise the risk to patients undergoing these procedures. As we gain more insight into the impact of the COVID-19 pandemic on cardiac activity, we will hopefully better understand whether particular groups of patients may be at greater risk of delaying procedures. This can better inform individual risk, but it is vital that, when counselling patients before ICD implantation, we discuss the pros and cons of proceeding versus delaying in future waves. As we may be living with this disease for some time, thought will need to be given to enabling training of medical and physiologist staff in these procedures, while keeping all safe.


The primary prevention ICD is a treatment for sudden death, and cessation of these procedures will put patients at risk. We have demonstrated that this service can be continued safely during the COVID-19 pandemic, and that patients are keen to continue with this treatment option. All steps should be taken to minimise the risk of hospital transmission of COVID-19, and this should be achievable, although sadly this is a patient group that is at high risk should they contract the infection. It is hopeful that future analysis of the UK audit data during the pandemic will better quantify the risks of delaying procedures, but in further surges of disease, we believe our experience supports the continuation of ICD implantation in patients for primary prevention.

Key messages

  • The routine suspension of primary prevention implantable cardioverter-defibrillator (ICD) implantation during the COVID-19 pandemic risks patient deaths on waiting lists
  • With appropriate infection prevention measures, these procedures can be safely maintained in a COVID-secure pathway
  • Patients value the ICD and are generally keen to proceed with their procedure despite the pandemic

Conflicts of interest

None declared.


No funding was received in relation to this article.

Study approval

This was a service evaluation and so formal ethical approval for the project was not required. It was, however, registered with the Trust Research and Innovation Department.


1. NHS England and NHS Improvement. Important and urgent – next steps on NHS response to covid-19. Available from: [accessed 27 September 2020].

2. NHS England and NHS Improvement. Clinical guide for the management of cardiology patients during the coronavirus pandemic. Version 1. 20 March 2020. Available from:

3. British Cardiovascular Society. British Cardiovascular Society statement: (unintended but inevitable) consequences of cancellation of cardiac procedures during the COVID-19 pandemic. Available from: [accessed 27 September 2020].

4. NHS. Important – for action – second phase of NHS response to COVID19. Available from: [accessed 27 Sept 2020].

5. National Institute for Cardiovascular Outcomes Research (NICOR). Rapid cardiovascular data: we need it now (and in the future). London: NICOR, 2020. [accessed 4 December 2020].