Pacemaker endocarditis: an important clinical entity

Clinical spectrum of Transthyretin amyloidogenic mutations among diverse population origins

PURPOSE

Coding mutations in the Transthyretin (TTR) gene cause a hereditary form of amyloidosis characterized by a complex genotype-phenotype correlation with limited information regarding differences among worldwide populations.

METHODS

We compared 676 diverse individuals carrying TTR amyloidogenic mutations (rs138065384, Phe44Leu; rs730881165, Ala81Thr; rs121918074, His90Asn; rs76992529, Val122Ile) to 12,430 non-carriers matched by age, sex, and genetically-inferred ancestry to assess their clinical presentations across 1,693 outcomes derived from electronic health records in UK biobank.

RESULTS

In individuals of African descent (AFR), Val122Ile mutation was linked to multiple outcomes related to the circulatory system (fold-enrichment = 2.96, p = 0.002) with the strongest associations being cardiac congenital anomalies (phecode 747.1, p = 0.003), endocarditis (phecode 420.3, p = 0.006), and cardiomyopathy (phecode 425, p = 0.007). In individuals of Central-South Asian descent (CSA), His90Asn mutation was associated with dermatologic outcomes (fold-enrichment = 28, p = 0.001). The same TTR mutation was linked to neoplasms in European-descent individuals (EUR, fold-enrichment = 3.09, p = 0.003). In EUR, Ala81Thr showed multiple associations with respiratory outcomes related (fold-enrichment = 3.61, p = 0.002), but the strongest association was with atrioventricular block (phecode 426.2, p = 2.81 × 10- 4). Additionally, the same mutation in East Asians (EAS) showed associations with endocrine-metabolic traits (fold-enrichment = 4.47, p = 0.003). In the cross-ancestry meta-analysis, Val122Ile mutation was associated with peripheral nerve disorders (phecode 351, p = 0.004) in addition to cardiac congenital anomalies (fold-enrichment = 6.94, p = 0.003).

CONCLUSIONS

Overall, these findings highlight that TTR amyloidogenic mutations present ancestry-specific and ancestry-convergent associations related to a range of health domains. This supports the need to increase awareness regarding the range of outcomes associated with TTR mutations across worldwide populations to reduce misdiagnosis and delayed diagnosis of TTR-related amyloidosis.

Epicardial Versus Endocardial Pacing in Paediatric Patients with Atrioventricular Block or Sinus Node Dysfunction: A Systematic Review and Meta-analysis

Pacing indications in children are clearly defined, but whether an epicardial (EPI) or an endocardial (ENDO) pacemaker performs better remains to be elucidated. This systematic review and meta-analysis aimed to directly compare the incidence of pacemaker (PM) lead-related complications, mortality, hemothorax and venous occlusion between EPI and ENDO in children with atrioventricular block (AVB) or sinus node dysfunction (SND). Literature search was conducted in MEDLINE (via PubMed), Scopus by ELSEVIER, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and OpenGrey databases until June 25, 2022. Random-effects meta-analyses were performed to assess the pacing method's effect on lead failure, threshold rise, post-implantation infection and battery depletion and secondarily on all-cause mortality, hemothorax and venous occlusion. Several sensitivity analyses were also performed. Of 22 studies initially retrieved, 18 were deemed eligible for systematic review and 15 for meta-analysis. Of 1348 pediatric patients that underwent EPI or ENDO implantation, 542 (40.2%) had a diagnosis of congenital heart disease (CHD). EPI was significantly associated with higher possibility of PM-lead failure [pooled odds ratio (pOR) 3.00, 95% confidence interval (CI) 2.05-4.39; I2 = 0%]; while possibility for threshold rise, post-implantation infection and battery depletion did not differ between the PM types. Regarding the secondary outcome, the mortality rates between EPI and ENDO did not differ. In sensitivity analyses the results were consistent results between the two PM types. The findings suggest that EPI may be associated with increased PM-lead failure compared to ENDO while threshold rise, infection, battery depletion and mortality rates did not differ.

Infective endocarditis by Serratia species: a systematic review

Serratia species are facultative anaerobes, non-spore-forming, motile Gram-negative bacteria. Serratia spp. are currently thought to cause a variety of infections, such as bacteremia, urinary tract infections, and pneumonia, as well as other, less common infections, including ocular infections or skin and soft tissue infections. On the other hand, Infective Endocarditis (IE) is an infrequent disease with notable morbidity and mortality. Even though IE is rarely caused by Serratia spp., these infections can be quite problematic due to the lack of experience in their management. This study aimed to systematically review all published cases of IE by Serratia spp. in the literature. A systematic review of PubMed, Scopus, and Cochrane library (through 13^th May 2021) for studies providing epidemiological, clinical, microbiological data as well as data on treatment and outcomes of IE by Serratia spp. was performed. In total, 50 studies, containing data for 72 patients, were included. A prosthetic valve was present in 18.1%. The mitral valve was the most commonly infected site, followed by the aortic valve. The diagnosis was facilitated by transthoracic echocardiography in 34.7%, while the diagnosis was set at autopsy in 22.4%. Fever, sepsis, and embolic phenomena were the most common clinical presentations, followed by heart failure. Aminoglycosides, cephalosporins, and carbapenems were the most commonly used antimicrobials. Clinical cure was noted only in 53.5%, while overall mortality was 47.2%. Having surgery along with antimicrobial treatment was independently associated with reduced overall mortality. IE by Serratia spp. was more likely to be associated with intravenous drug use, and to present with heart failure and embolic phenomena compared to IE by other non-HACEK Gram-negative bacilli, while mortality was also higher in IE by Serratia spp.

Elusive Enterobacter cloacae causing pacemaker endocarditis

An 80-year-old patient was admitted for fever, chills, and chest wall pain. He had a past medical history significant for heart failure with a cardiac resynchronization therapy pacemaker implantation. Extensive workup revealed Enterobacter cloacae endocarditis of the pacemaker leads and the mitral valve, a rare etiology with an unidentified source in our patient. He was managed with a rather unconventional method which proved to be successful. This case sheds light on non-HACEK (other than Haemophilus spp., Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, or Kingella spp). gram-negative organisms, and particularly E. cloacae, as uncommon causes of endocarditis with elevated mortality, and discusses potential treatment modalities.

A Rare Entity-Percutaneous Lead Extraction in a Very Late Onset Pacemaker Endocarditis: Case Report and Review of Literature

The number of infections related to cardiac implantable electronic devices (CIEDs) has increased as the number of devices implanted around the world has grown exponentially in recent years. CIED complications can sometimes be difficult to diagnose and manage, as in the case of lead-related infective endocarditis. We present the case of a 48-year-old male diagnosed with Staphylococcus aureus device-related infective endocarditis, 12 years after the implant of a single chamber pacemaker. A recent history of the patient includes two urinary catheterizations due to obstructive uropathy in the context of a prostatic adenoma, 2 months previously, both without antibiotic prophylaxis; no other possible entry sites were found and no history of other invasive procedures. After initiation of antibiotic therapy according to antibiotic susceptibility testing, we decided to remove the right ventricular passive fixation lead along with the vegetation and pacemaker generator; because of severe lead adhesions in the costoclavicular region, and especially in the right ventricle, we needed mechanical sheaths to remove the abundant fibrous tissue that encompassed the lead. After a difficult, but successful, lead extraction along with a large vegetation and 6 weeks' antibiotic therapy, the clinical and biological evolution was favorable, without reappearance of symptoms. While very late lead endocarditis is a rarity, late lead-related infective endocarditis (more than 12 months elapsed since implant) is not an exception; this is why we find that endocarditis prophylaxis should be reconsidered in certain patient categories, our patient being proof that procedures with neglectable endocarditis risk according to the guidelines can lead to bacterial endocarditis.

Serratia marcescens and other non-AACEK GNB endocarditis: A case report and review of literature

BACKGROUND

Non-Aggregatibacter aphrophilus, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella spp. (non-AACEK) gram-negative bacilli (GNBs) are an infrequent and challenging cause of endocarditis associated previously with mainly intravenous drug use. Currently, this pathology has increasingly become a healthcare-associated issue. Current guidelines do not clearly define the management of non-AACEK GNB endocarditis due to a lack of prospective trials. We review characteristics, outcomes and treatment of non-AACEK GNB endocarditis, in particular Serratia marcescens endocarditis.

CASE SUMMARY

We describe the case report of a 46-year-old man who presented to the emergency department with high-grade fever and a purulent exudate on an intracardiac device site. Serratia marcescens mitral valve endocarditis as a consequence of complicated generator pocket infection was diagnosed. The patient was treated with complete device removal and a long course of broad-spectrum antibiotics for 6 wk after surgery with intravenous piperacillin-tazobactam and ciprofloxacin, which was later switched to oral ciprofloxacin and sulfamethoxazole-trimethoprim. The patient had complete resolution of symptoms and inflammatory parameters at the end of the treatment and at follow-up.

CONCLUSION

Long-term dual-antibiotic therapy containing a beta-lactam is indicated for most non-AACEK GNB endocarditis, whereas valve surgery may not be necessary in all patients.

A Complicated Case of Serratia marcescens Infective Endocarditis in the Era of the Current Opioid Epidemic

While bacteremia due to Serratia marcescens is not uncommon, it rarely causes infective endocarditis. We report an isolated case of a 53-year-old male with history of intravenous drug abuse who presented with multiple acute pain symptoms and was found to have S. marcescens bacteremia with septic emboli in his spleen, brain, and testes, secondary to a large aortic vegetation, as well as aortic infective endocarditis with severe aortic regurgitation requiring aortic valve replacement. His course of disease was further complicated by epidural and psoas abscesses and a necrotic testicle requiring orchiectomy due to his ongoing intravenous drug abuse. This case is an atypical presentation of S. marcescens infection, as he had no overt signs of infection such as fever or significant leukocytosis that are typical of bacteremia, and it also highlights the severity and complicated nature of S. marcescens-infective endocarditis.

Marvelous but Morbid: Infective endocarditis due to Serratia marcescens

A 46-year-old man with HIV infection and active intravenous drug use presented with approximately two weeks of fevers and body aches. On physical examination he was somnolent, had a new systolic murmur, bilateral conjunctival hemorrhages, diffuse petechiae, and left-sided arm weakness. Echocardiography revealed a large mitral valve vegetation and brain imaging demonstrated numerous embolic infarctions. Blood cultures grew Serratia marcescens. Despite aggressive treatment with meropenem the patient died due to intracranial hemorrhage complicated by herniation. Serratia marcescens is an uncommon cause of infective endocarditis. While this disease has historically been associated with intravenous drug use, more recent reports suggest that it is now largely a consequence of opportunistic infections of the chronically ill. Our case highlights several characteristic features of this infection, including isolation of a non-pigmented strain of the organism, an antibiotic susceptibility profile suggestive of AmpC β-lactamase production, and rapid clinical deterioration with multiple embolic complications resulting in death. In this review we discuss the history, epidemiology, and management of endovascular infections due to Serratia spp., emphasizing the continued importance of considering this organism in the differential diagnosis of endocarditis among intravenous drug users and as a potential indication for surgical therapy.