Complications of retained cardiac defibrillator coil left in situ

Abstract

A 42-year-old man presented to a regional hospital emergency department with a 4-day history of haemoptysis, shortness of breath, pleuritic chest pain, productive cough and subjective fevers. This episode was the third similar presentation in a 2-month period. The patient was known to have dilated cardiomyopathy secondary to amphetamine use and had previously required insertion of automated implantable cardiac defibrillator (AICD). Due to recurrent complications, the AICD had been replaced on two occasions and a superior vena cava (SVC) lead left in situ on its final removal. Clinical examination and investigations revealed lower respiratory tract infection and transthoracic echocardiogram revealed severe left ventricular failure with an ejection fraction of 16%. The patient was admitted under the general medical team for treatment and investigation of suspected bacteraemia and septicaemia secondary to colonisation of the retained AICD lead. He spent 6 days as an in-patient and was discharged on home where he was to be followed up by the advanced heart failure team in a tertiary centre for consideration of new AICD insertion and to explore possibility of retained coil removal. This case report discusses the concerns surrounding retained SVC leads and potential clinical sequalae. As this patient presented three times within a period of 2 months, it was suspected retained SVC lead was a predisposing factor for recurrent lower respiratory infection

Background

An estimated 10 000–15 000 pacemaker and implantable cardioverter-defibrillator (ICD) leads are removed worldwide per year. While removing leads is likely to be beneficial, extraction of leads may disrupt the encapsulating fibrous tissue and can rarely lead to fatal cardiovascular injuries including catastrophic venous tears myocardial injury and perforation. Conversely, leaving automated implantable cardiac defibrillator (AICD) leads in situ may expose the patient to device colonisation by opportunistic bacteria resulting in fulminant infection or bacterial endocarditis.

Case presentation

A 42-year-old man presented to a regional hospital Emergency Department with a 4-day history of haemoptysis, shortness of breath, pleuritic chest pain, productive cough and subjective fevers. This was the third similar presentation in the preceding 2 months, during which he had been treated for community acquired pneumonia (CAP) with intravenous and oral antibiotics (benzyl-penicillin and doxycycline respectively, as per local guidelines). On both previous occasions, the patient had made significant improvements, and was discharged home with oral antibiotics.

On arrival, clinical examination demonstrated mild tachycardia, normal blood pressure and temperature, and the patient was displaying no dyspnoea. Mild signs of congestive cardiac failure (CCF) were noted, including raised jugular-venous pressure (4 cm), bilateral pitting oedema to the mid shins and bilateral fine crepitations on auscultation.

The patients’ medical history included dilated cardiomyopathy secondary to chronic amphetamine abuse, hepatitis C (treated and sustained viral response attained in 2017), hypertension, bipolar disorder and Perthes disease. His regular medications were bisoprolol, lithium, aspirin and meloxicam.

The patient had an AICD placed as a primary prevention strategy for his dilated cardiomyopathy in 2006. This unit was replaced twice in the following 10 years due to unit faults including inappropriate shock delivery and lead malfunction. On the third attempt, the unit became colonised with Staphylococcus epidermidis resulting in a suboptimal internal pocket, systemic bacteraemia and suspected vegetations in the right atrium. Due to these recurrent complications, it was decided that the AICD would be removed permanently in 2017. However, on retrieval of the leads, the patient developed complications including superior vena cava (SVC) thrombus and bilateral pulmonary embolism and as a result, the procedure was abandoned and the lead was left in situ. He was treated with long-term anticoagulation and antibiotics in consultation with the local infectious diseases team and was symptom free for the next 3 years.

Investigations

ECG showed long-standing T-wave inversions in lateral leads and left axis deviation. All other bedside tests were normal.

Routine blood tests demonstrated elevated inflammatory markers with white cell count of 23.05×10⁹/L (normal 4.5–11×10⁹/L), total neutrophil count of 17.45×10⁹/L (normal 2–7.5×10⁹/L) and C reactive protein (CRP) 14 mg/L (normal <3 mg/L). The patient as also found to have an acute kidney injury with creatinine elevated at 216 μmol/L (normal <110 μmol/L).

Imaging included a chest X-ray that revealed upper lobe diversion with mild cardiomegaly and left mid zone consolidation. Remainder of SVC coil was visualised (figure 1).

Figure 1.

Chest X-ray—PA view of the patient showing the SVC coil in situ. PA, posteroanterior; SVC, superior vena cava.

His echocardiogram revealed dilated left ventricle with severely impaired systolic function with bi-atrial dilatation. His right ventricle was also dilated and hypokinetic. Moderate mitral regurgitation and tricuspid regurgitation were evident with trace aortic regurgitation. His ejection fraction (EF) was 16%. No regional wall abnormalities were seen.

Differential diagnosis

The patient was provisionally diagnosed with recurrent left-sided CAP with underlying acute exacerbation of CCF. Hypothesised causes for the exacerbation included medication non-compliance, or potential ongoing illicit substance abuse.

Treatment

On admission to the general medical ward, the patient was prescribed intravenous ceftriaxone for 4 days and oral doxycycline for 5 days, which resulted in rapid clinical and biochemical improvement (white cell count 13.43×10⁹/L and CRP 6 mg/L) and two subsequent negative blood and sputum cultures. During this admission, the patients Frusemide regime was optimised with close monitoring of renal function, and the patient achieved adequate diuresis (2 kg loss in 3 days) and improvement of clinical symptoms including exercise tolerance.

The patient was then discharged home a 3-day course of oral cefuroxime, and was to be followed up as an outpatient.

Outcome and follow-up

The patient was referred to the local tertiary centre cardiothoracic unit for review in light of possible removal of the retained SVC coil, as well as optimisation prior to this potential procedure.

His last echocardiogram available was from 12 months ago prior to this presentation, this revealed mild global hypokinesia with a left ventricular EF of 49%.

To address his deteriorating cardiac function and reduced EF, he was referred to the local cardiologist with subsequent referral to the advanced heart failure team. This referral was made with the aim of improving his treatment compliance and support the patient’s abstinence from illicit drug use which may eventually lead to consideration for heart transplantation in the future.

At the time of this publication, the patient was being followed up at a tertiary centre under outpatient cardiology team for his congestive heart failure. He has been commenced on bisoprolol 2.5 mg once daily, Sacubitral/Valsartan 24/26 mg two times a day and his regular frusemide dose has been up titrated to 40 mg twice a day from once a day. Medication optimisation and support with lifestyle changes has been successful to this point, and his most recent transthoracic echocardiogram (TTE) has demonstrated improvement of his left ventricular EF. Repeat TTE revealed severely dilated left ventricle with severe global systolic function with dilated right ventricle with systolic impairment. Moderate functional mitral regurgitation and severely dilated left atrium were evident. EF was 30%.

Discussion

Management of relatively common complications of AICD such as lead displacement, pocket infection and malfunction is relatively well established.¹ However, there remains a scarcity in literature with regard to management of potential adverse effects of retained AICD or pacemaker leads which have been failed to be removed.

It is well understood from microbiology principles and case studies in regards to other implanted devices, that foreign material within the body is susceptible to colonisation by bacteria, and may expose the patient to subsequent sequalae of bacteraemia. As a result, a risk versus benefit analysis must be undertaken in each case, to determine if the patient is at higher risk of complications of bacteraemia, or removal of the foreign body directly or indirectly.

In this case, the patient presented three times in a 2-month period with a high degree of suspicion that he was predisposed to infection because of the retained AICD leads.

Peters et al ² have shown, in vitro and in vivo, that some Staphylococci can grow on the plastic sheath of the pacemaker wire without external supplies. These bacteria produce a slimy amorphous material (biofilm) that may be important in the Staphylococcal defence against host defence mechanisms and antibiotic treatment, and in the maintenance of colonisation. This is believed to be the reason why lead infections are hard to manage conservatively and lead extraction is almost always advisable.

However, lead extraction is not always straight forward, as seen in this case study. When considering a risk versus benefit analysis for the patient, all outcomes should be considered. Complete removal of all the foreign material is suggested when pacemaker or AICD system infection occurs, whether it is systemic or local infection at pocket site.^3–5

This is supported by two retrospective studies by Sohail et al ⁶ and Rodriguez et al,⁷ both of which supported aggressive treatment involving antimicrobial treatment and complete device removal showed high cure rate from cardiac device infection (CDI). However, this needs to be considered in light of the morbidity and mortality associated with the procedure. A study by Byrd et al ⁸ that analysed lead extraction from 3450 leads from 2338 patients, found that pacemaker or AICD right ventricular (RV)-lead extraction carries a significant morbidity risk between 1.4% and 2.5%.^{8 9}

The study concluded that physician experience, appropriate precautions, appropriate patient selection and contemporary lead-removal techniques allow success with low complication rates. However, In case of recurrent CDI, abandoned AICD leads complicate the overall management.¹⁰ Previously abandoned leads are associated with more complex extraction procedures, worse clinical outcomes, lower success rates and higher complication rates.

To further complicate the patients clinical scenario, given the patients very poor echocardiogram results, he will likely require another cardioverter-defibrillator in the near future subcutaneous ICD has been shown across patient populations to be a safe and effective device for appropriately sensing malignant ventricular arrhythmias and delivering successful rescue therapy.¹¹ This may be an option for patients who will need an ICD systems who at risk of having recurrent CDI.

Due to the paucity of strong evidence and published guidelines regarding the removal of retained AICD leads, current best practice varies on a case-by-case basis, and depends on local expert opinion and careful consideration of patient comorbidities and risk factors. This case highlights the need for consideration of clear guidelines in such cases, which may aid the clinicians facing the same dilemma.

Learning points.

• Automated implantable cardiac defibrillator (AICD) or pacemaker leads left in situ may cause immediate or late complications.

• Currently, there are no clear management guidelines for complications that may arise from AICD or pacemaker leads left in situ and managed case by case.

• If there are absolute contraindications for AICD insertion, middle-aged patients with heart failure should be considered for heart transplant.

• To explore with newer lead-removal methods in cases which have been unsuccessful previously.