Cardiac myocytes of hearts from patients with end-stage dilated cardiomyopathy do not contain Borrelia burgdorferi DNA

Risk of heart failure among individuals tested for Borrelia burgdorferi sensu lato antibodies, and serum Borrelia burgdorferi sensu lato seropositive individuals; a nationwide population-based, registry-based matched cohort study

BACKGROUND

Lyme borreliosis is a tick-borne disease caused by the bacterium Borrelia burgdorferi (Bb) sensu lato complex. Previous studies have suggested an association between Lyme borreliosis and heart failure, which have been suggested to be a possible manifestation of Lyme carditis. We aimed to investigate the risk of heart failure among individuals tested for serum Bb antibodies, and serum Bb seropositive individuals.

METHODS

We performed a matched nationwide cohort study (Denmark, 1993-2020) and included 52,200 Bb seropositive individuals, and two age- and sex-matched comparison cohorts: 1) 104,400 Bb seronegative comparison cohort members, and 2) 261,000 population controls. We investigated the risk associated with 1) being tested for serum Bb antibodies, and 2) being Bb seropositive. Outcomes were: 1) a composite of heart failure, cardiomyopathy, and/or myocarditis diagnosis, and 2) redemption of cardiovascular medicine used for treatment of heart failure. We calculated short-term odds ratios (aOR) (within 1 month) and long-term hazard rates (aHR) (after 1 month) adjusted for age, sex, diabetes, pre-existing heart failure, and kidney disease.

RESULTS

Compared with the population controls, individuals tested for Bb antibodies, regardless of the test result, had increased short-term risk of heart failure, cardiomyopathy, and myocarditis (aOR 8.3, 95 %CI: 6.7-10.2), and both increased short- and long-term risk of redemption of cardiovascular medicine (aOR 4.3, 95 %CI: 3.8-4.8, aHR 1.13, 95 % CI: 1.11-1.15). The Bb seropositive individuals had no increased short- or long-term risk of any outcome compared with Bb seronegative comparison cohort members.

CONCLUSIONS

In conclusion, Bb antibody tests seemed to be performed in the diagnostic work-up of heart failure, but Bb seropositivity was not associated with heart failure.

Disseminated Lyme disease and dilated cardiomyopathy: A systematic review

Lyme carditis is a well-established manifestation of early disseminated Lyme infection, yet the relationship between late disseminated Lyme disease and the development of dilated cardiomyopathy (DCM) remains unclear. The present systematic review aims to summarize existing literature on the association between late disseminated Lyme disease and DCM. A systematic review was conducted in PubMed, Embase, CENTRAL, and MEDLINE databases, after which a total of 11 observational studies (n = 771) were ultimately included for final data extraction. Although most studies (7/11) identified evidence associating Borrelia-infection with DCM, further research is required to isolate late disseminated Borrelia infection as a causative agent of DCM.

Manifestations of Lyme carditis

The first data of Lyme carditis, a relatively rare manifestation of Lyme disease, were published in eighties of the last century. Clinical manifestations include syncope, light-headedness, fainting, shortness of breath, palpitations, and/or chest pain. Atrioventricular (AV) electrical block of varying severity presents the most common conduction disorder in Lyme carditis. Although is usually mild, AV block can fluctuates rapidly and progress from a prolonged P-R interval to a His-Purkinje block within minutes to hours and days. Rarely, Lyme disease may be the cause of endocarditis, while some studies and reports, based on serological and/or molecular investigations, have suggested possible influence of Borrelia burgdorferi on degenerative cardiac valvular disease. Myocarditis, pericarditis, pancarditis, dilated cardiomyopathy, and heart failure have also been described as possible manifestations of Lyme carditis. The clinical course of Lyme carditis is generally mild, short term, and in most cases, completely reversible after adequate antibiotic treatment.

Lyme carditis--diagnosis, treatment and prognosis

BACKGROUND

There are 60,000 to 100,000 new cases of borreliosis in Germany each year. This infectious disease most commonly affects the skin, joints, and nervous system. Lyme carditis is a rare manifestation with potentially lethal complications.

METHODS

This review is based on selected publications on the clinical manifestations, diagnosis, and treatment of Lyme carditis, and on the authors' scientific and clinical experience.

RESULTS

Lyme carditis is seen in 4% to 10% of all patients with Lyme borreliosis. Whenever the clinical suspicion of Lyme carditis arises, an ECG is mandatory for the detection or exclusion of an atrioventricular conduction block. Patients with a PQ interval longer than 300 ms need continuous ECG monitoring. 90% of patients with Lyme carditis develop cardiac conduction abnormalities, and 60% develop signs of perimyocarditis. Borrelia serology (ELISA) may still be negative in the early phase of the condition, but is always positive in later phases. Cardiac MRI can be used to confirm the diagnosis and to monitor the patient's subsequent course. The treatment of choice is with antibiotics, preferably ceftriaxone. The cardiac conduction disturbances are usually reversible, and the implantation of a permanent pacemaker is only exceptionally necessary. There is no clear evidence at present for an association between borreliosis and the later development of a dilated cardiomyopathy. When Lyme carditis is treated according to the current guidelines, its prognosis is highly favorable.

CONCLUSION

Lyme carditis is among the rarer manifestations of Lyme borreliosis but must nevertheless be considered prominently in differential diagnosis because of the potentially severe cardiac arrhythmias that it can cause.

Detection of Borrelia burgdorferi sensu lato in endomyocardial biopsy specimens in individuals with recent-onset dilated cardiomyopathy

AIMS

Recent studies in patients with dilated cardiomyopathy (DCM) have detected the genome of Borrelia burgdorferi sensu lato (BBSL) in endomyocardial biopsy (EMB) specimens using a qualitative polymerase chain reaction (PCR), suggesting a causal link between Lyme disease and DCM in areas in which Lyme disease is endemic. We aimed to study this relationship using a comprehensive molecular analysis detecting BBSL in EMB samples.

METHODS AND RESULTS

We performed a comprehensive histopathological, immunohistochemical, ultrastructural, and molecular analysis targeting cardiotropic viruses and BBSL in EMB specimens of 41 individuals with recent-onset DCM and 15 controls with end-stage coronary artery disease. Specifically, quantitative PCR and electron microscopy of EMB specimens were employed. In addition, autoantibodies and manifestation of autoimmune diseases were evaluated in both groups. Individuals with recent-onset DCM presented more frequently with myocardial BBSL persistence as compared with the control group (24% vs. 0%, P = 0.035). In contrast, the prevalence of parvovirus B19 and cytomegalovirus was similar in both groups. Sequence analysis of borrelial DNA revealed the following genospecies: Borrelia burgdorferi sensu stricto in three patients (30%), Borrelia afzelii in two patients (20%), and Borrelia garinii in four patients (40%), the results being inconclusive in one case. BBSL-positive DCM patients had a higher prevalence of organ-specific autoimmune diseases in comparison with the remaining DCM patients (50% vs. 16%, P = 0.030).

CONCLUSION

Myocardial persistence of BBSL may be involved in the pathophysiology of DCM in individuals living in areas in which Lyme disease is endemic.

The role of viral infections in the development of dilated cardiomyopathy

Enteroviruses (EVs) are the most frequent pathogens in myocarditis and in the subsequently developing dilated cardiomyopathy as well. Furthermore, persistence of other viruses might play a pathogenic role in the evolution from myocarditis to dilated cardiomyopathy. Explanted heart of 28 patients, who underwent heart transplantation were screened for EV, AdV3 and HHV6 sequences in order to assess the incidence of cardiac viral infection that may be implicated in the pathogenesis of cardiomyopathy, and estimate viral distribution in the myocardium. Viral sequences were extracted from five different regions of the hearts. Nested PCR was used to amplify conservative regions of AdV3, HHV6 and EVs. Histological examination was performed on routinely processed myocardial samples. AdV3 was verified in one fourth of the patients. ADV3 and HHV6 sequences coexisted in one case with inflammatory cardiomyopathy. Some patients had more than one positive area of their heart. AdV3 positive right ventricular samples were double in amount compared to the left ones. None of the patients had positive result for EV. This is the first occasion to identify AdV3 (a mainly respiratory infective virus) sequence in explanted hearts of cardiomyopathy patients. Though the clinical importance of our results is still unclear, AdV3 could be a new member of the viral group with possible pathogenic effect on the myocardium. Regional distribution of viral sequence location confirmed that the right ventricular wall as a biopsy sampling site might be adequate for endomyocardial biopsy pro diagnostic purposes.

Presence of Borrelia burgdorferi in endomyocardial biopsies in patients with new-onset unexplained dilated cardiomyopathy

Dilated cardiomyopathy (DCM) represents the third most common cause of heart failure and the most frequent cause of heart transplantation. Infectious, mostly viral, and autoimmune mechanisms, together with genetic abnormalities, have been reported as three major causes of DCM. We hypothesized that Lyme disease (LD), caused by spirochete Borrelia burgdorferi (Bb), might be an important cause of new-onset unexplained DCM in patients living in a highly endemic area for LD such as the Czech Republic. We performed endomyocardial biopsy (EMB) in 39 consecutive patients presenting with symptomatic unexplained left ventricular (LV) systolic dysfunction lasting no more than 12 months. In eight subjects (21%), Bb was detected in the EMB sample by polymerase chain reaction or by electron microscopy. None of these patients exhibited any form of atrioventricular block or other extracardiac manifestation of Bb infection. Serological testing identified IgG antibodies against Bb in only two cases and IgM antibodies in none. All affected patients were treated with intravenous ceftriaxone for 3 weeks. At 6 months follow-up, LV morphology and function as well as functional status of these patients significantly improved. In conclusion, Bb infection may represent an important cause of new-onset unexplained DCM in patients living in endemic regions such as the Czech Republic. Because the antibiotic treatment appears to be markedly effective and serological examination does not provide a tool for diagnosing the disease, EMB focused on the detection of Bb should be performed in all patients from endemic areas with new-onset unexplained DCM not responding to conventional therapy.

[Lyme arthritis, Lyme carditis and other presentations potentially associated to Lyme disease]

Lyme disease or Lyme borreliosis is the most common tick-transmitted disease in the Northern hemisphere and is caused by Borrelia burgdorferi spirochetes. Lyme disease commonly begins with a characteristic skin lesion, erythema migrans. Weeks or months later, the patients may have neurologic, joint, or cardiac abnormalities. Some patients may still present persistent deep fatigue and various unspecific symptoms after standard courses of antibiotic treatment for Lyme disease. This constellation of symptoms has been variously referred to as "chronic Lyme disease", or "post-Lyme disease syndrome". The first French National Consensus Conference on Lyme Disease was the reason to review all aspects of articular and cardiac manifestations of Lyme disease after a synthesis of recent literature. The involvement of Borrelia species in chronic Lyme disease and other pathologies is discussed.

Atteinte cardiaque dans la maladie de Lyme

Cardiac manifestations of Lyme Borreliosis are relatively infrequent, occurring within weeks after the infectious tick bite (median of 21 days), and resulting at this stage from a direct borrelial infection of the myocardium, as indicated by reports of spirochete isolation from pericardium and myocardium. They may persist or appear in the late, tertiary phase of the illness, being then more likely due to infection-triggered autoimmunity. Lyme carditis typically presents with a fluctuating degree of atrioventricular block that spontaneously resolves in several days. Rarely, myocarditis may occur with or without pericardial involvement, in patients presenting with chest pain, ST depression or T wave inversion, mimicking an acute myocardial infarction, and various arrhythmias are reported, as well as pericardial effusion or heart failure. A complete recovery is usually observed, spontaneous or after antibiotherapy. Severe myocarditis or Pericarditis leading to death is exceptional. The diagnosis of Lyme carditis is based on the same association of clinical and laboratory features as in Lyme disease without cardiac involvement. But the occurrence of conduction disturbances in healthy young people suggests screening for other criteria of Lyme disease. The management of Lyme carditis does not differ from the treatment of Lyme disease without carditis and is mainly based upon the use of doxycycline or ceftriaxone.

Update on Lyme Carditis

Lyme carditis is an uncommon manifestation of infection with Borrelia bugdorferi. It is easily treated with standard antibiotic regimens and prognosis is excellent, especially if treatment is prompt. For symptomatic or higher degrees of block, patients may require hospitalization for monitoring and occasionally temporary external pacing. Intravenous antibiotics are warranted for such patients. For less severe conduction disturbances, oral therapy suffices.