Clinical, Radiographic, and Microbiologic Features of Infective Endocarditis in Patients With Hypertrophic Cardiomyopathy

Infective endocarditis

First described more than 350 years ago, infective endocarditis represents a global health concern characterised by infections affecting the native or prosthetic heart valves, the mural endocardium, a septal defect, or an indwelling cardiac device. Over recent decades, shifts in causation and epidemiology have been observed. Echocardiography remains pivotal in the diagnosis of infective endocarditis, with alternative imaging modalities gaining significance. Multidisciplinary management requiring expertise of cardiologists, cardiovascular surgeons, infectious disease specialists, microbiologists, radiologists and neurologists, is imperative. Current recommendations for clinical management often rely on observational studies, given the limited number of well conducted randomised controlled trials studying infective endocarditis due to the rarity of the disease. In this Seminar, we provide a comprehensive overview of optimal clinical practices in infective endocarditis, highlighting key aspects of pathophysiology, pathogens, diagnosis, management, prevention, and multidisciplinary approaches, providing updates on recent research findings and addressing remaining controversies in diagnostic accuracy, prevention strategies, and optimal treatment.

The Deadly Contaminant: A Case of Staphylococcus lugdunensis Endocarditis

The incidence of infective endocarditis (IE) has been on the rise since it was first reported a century ago, and the associated mortality remains unchanged despite advances in medical and surgical management. To diagnose IE, the modified Duke criteria are used, which rely on isolating the causative organism. However, this can be challenging if the micro-organism is considered a contaminant. Staphylococcus lugdunensis (SL) is one such organism. In this case, an elderly female presented with intermittent chest pain, palpitation, and diaphoresis, for which she underwent left heart catheterization. Her hospital course was complicated by persistent fever and night sweats, leading to blood cultures isolating methicillin sensitivity. It was initially reported as a contaminant. However, an extensive workup was unremarkable, and a transthoracic echocardiogram was done, which revealed tricuspid vegetations with moderate regurgitation. The patient was treated with cefazolin, repeat cardiac imaging at the end of treatment revealed no vegetation, and the patient remained asymptomatic. Despite being associated with fulminant IE with higher mortality than Staphylococcus aureus (S. aureus), which requires surgical management in most cases, SL is still often reported as a contaminant. Isolation of SL should warrant further investigation beyond mere contaminants, and prompt treatment should be initiated in the appropriate clinical scenario to avoid poor outcomes.

Clinical profile and outcomes of pediatric hypertrophic cardiomyopathy in a South Indian tertiary care cardiac center: a three decade experience

INTRODUCTION

Although much research has been done on adult hypertrophic cardiomyopathy, data on pediatric hypertrophic cardiomyopathy is still limited.

METHODS AND RESULTS

The study enrolled all patients with cardiomyopathy who presented to us between 1990 to 2020 and were younger than 18 yrs. During the thirty-year study period, we identified 233 cases of pediatric cardiomyopathy. Sixty-three cases (27%) had hypertrophic cardiomyopathy. Out of the 63 HCM cases, 12% presented in the neonatal period and 37% presented in the first year of life. The median age of presentation was 7 yrs (Range 0.1-18 yrs). Sixteen patients had proven syndromic, metabolic, or genetic disease (25%). LV outflow obstruction was present in 30 patients (47%). Noonan syndrome was present in 9 of the 63 patients (14%). Dyspnea on exertion was the most common mode of presentation. Cardiac MRI was done in 28 patients, out of which 17 had late gadolinium enhancement (LGE). Mid myocardial enhancement was the most common pattern. Four patients had LGE of more than 15%. Over a mean follow-up period of 5.6 years (0.1-30 years), twenty-one were lost to follow-up (33%). Among the patients whose outcome was known, eleven died (26%), and thirty-one (73%) were alive. The 5-year survival rate of HCM patients was 82%, and the 10-year survival rate was 78%. Seven died of sudden cardiac death, three from heart failure, and one from ventricular arrhythmias. Sustained ventricular arrhythmias were seen in three patients and atrial arrhythmias in two. First-degree AV block was seen in 10 patients (15%) and bundle branch blocks (BBB) in five (8%). Eight patients required ICD or transplant (12.7%). Two patients underwent ICD for primary prevention, and one underwent PPI for distal AV conduction disease. Among the various clinical, echocardiographic, and radiological risk factors studied, only consanguinity showed a trend towards higher events of death or ventricular arrhythmias (P-value 0.08).

CONCLUSION

More than one-third of our HCM cohort presented in infancy. LV outflow tract obstruction is common (47%). Mid myocardial enhancement was the most common pattern of late gadolinium enhancement. SCD was the most common cause of death. The outcome in our HCM cohort is good and similar to other population cohorts. Only Consanguinity showed a trend towards higher events of death or ventricular arrhythmias.

Surgical Management of Hypertrophic Cardiomyopathy Complicated by Infective Endocarditis

BACKGROUND

Infective endocarditis (IE) is a serious complication in hypertrophic cardiomyopathy (HCM). Cardiac surgery is often necessary, however, literature assessing surgical outcomes is limited.

METHODS

From December 1995 to September 2018, 43 patients with a history of HCM and native valve IE underwent cardiac surgery at our institution. Relevant data were abstracted from medical records and analyzed.

RESULTS

Median age was 57 years (IQR 45-67), 81% (n=35) were male. IE was active in 21% (n=9) patients at the time of surgery; Of these, the suspected origin of infection was orodental in 19% (n=8) patients. Significant mitral valve regurgitation was detected in 54% (n=23) patients and aortic valve regurgitation in 7% (n=3). Septal myectomy (SM) was performed in 95% (n=41) patients, with concomitant valve surgery in 58% (n=25) including prosthetic replacement in 28% (n=12). Two patients underwent double valve replacement without SM. Outflow gradients improved from median 67mmHg (IQR 34-97 mmHg) to 9mmHg (IQR 6-22 mmHg). One in-hospital death occurred due to uncontrollable pulmonary edema. As of last follow up, seven patients required reoperation and the 5 and 10-year cumulative incidences were 11% and 26%. Ten deaths occurred and overall survival probability at 5 and 10-years was 94% and 78% respectively.

CONCLUSIONS

Valvular complications of IE add complexity to surgical management of HCM. There is an increased need for concomitant valve repairs, prosthetic replacements and reoperation. These data underscore the need for recognition of infection, especially after oral procedures, which preceded majority of the active IE cases.

WITHDRAWN: Application of Echocardiographic Information Technology in the Research of Infective Endocarditis and Its Neurological Complications

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Infective Endocarditis: A Contemporary Review

Infective endocarditis (IE), initially described more than 350 years ago, involves infection of the endocardial surface of the heart. The clinical manifestations of IE can involve every organ system, and the cardiac manifestations can include valvular vegetation, abscess, periannular extension of infection, and myopericarditis. Echocardiography is crucial in the diagnosis of IE, but alternative imaging modalities are playing an increasing role in the diagnosis and management of IE. Multidisciplinary care is imperative to the management of IE, often requiring the expertise of cardiologists, cardiothoracic surgeons, infectious diseases specialists, radiologists, and neurologists. We performed a literature search of the PubMed database from January 1st, 2000, to September 30th, 2019, using the terms infective endocarditis, diagnosis, and management to find the most pertinent and highest-quality evidence. This review summarizes key aspects of IE, with a focus on emerging advances in diagnosis. We also highlight growing patient populations at risk for IE, including patients with intracardiac devices and congenital heart disease.

Streptococcus viridans Endocarditis Affecting All Four Valves

Infective endocarditis (IE) affecting all four valves is rare. We describe an interesting clinical scenario of a 47-year-old female, with an underlying, unrepaired atrial septal defect (ASD) and hypertrophic obstructive cardiomyopathy (HOCM), who presented with a five-week history of worsening lower extremity rash and New York Heart Association (NYHA) class IV symptoms. She was febrile to 101.3°F at the time of presentation. Examination revealed dental caries and track mark on hands. Her extremities demonstrated palpable purpura and pitting edema. Chest auscultation revealed bibasilar crackles and a grade III pan-systolic murmur, best heard over the apex, with radiation to the axilla. The blood gram stain resulted positive for gram-positive cocci in chains, prompting the initiation of ceftriaxone. Transthoracic echocardiography (TTE) did not reveal any new valvular regurgitation or vegetation. Transesophageal echocardiography (TEE) showed vegetation on all four valves and underlying ASD with HOCM. Blood cultures grew Streptococcus viridians. She had evidence of extensive septic emboli to the brain, lungs, spleen, and intestines. Given the extent of valvular involvement, intracranial hemorrhage, and tenuous hemodynamic status, a decision was taken to manage her conservatively followed by elective surgical management. She, however, went into cardiogenic shock further complicated by lower gastrointestinal bleed and passed away.