Native aortic versus mitral valve infective endocarditis: a nationwide registry study

Surgery for Active Infective Endocarditis on Mitral Valve: Anatomical, Surgical, and Disease Factors as Long-Term Outcome Modifiers

Background and Objectives: Determinants of long-term outcomes after surgery for native mitral valve endocarditis have not been thoroughly investigated. The aim of this study was to assess anatomical, disease, and surgical risk factors for long-term mortality and need of reintervention, in patients undergoing mitral valve surgery for active endocarditis. Materials and Methods: Patients who underwent surgery for active native mitral valve endocarditis at three academic centres, between 2000 and 2022, were analysed. The primary outcome was long-term survival. The secondary outcome was the freedom from mitral reoperation. Survival curves were constructed with Kaplan-Meier methodology. Multivariable Cox regression was used to identify demographic, anatomical, disease, and surgical factors associated with late mortality and reoperation. Results: 335 consecutive patients with active mitral endocarditis were analysed. Two hundred and one patients (70.5%) had infection confined to the valve cusp whereas 89 (25.6%) had invasive disease extended to the annulus and surrounding tissues. Preoperative neurological events occurred at the diagnosis in 52 cases. Streptococci were the most common causative organisms followed by Staphylococcus aureus, Coagulase-negative Staphylococcus, and Enterococcus. Valve repair was performed in 108 patients (32.2%). Survival at 5 and 10 years was 70.1% and 59.2%, respectively. Staphylococcus emerged as an independent predictor of late mortality, along with age, chronic obstructive pulmonary disease, and previous cardiac surgery. Survival was considerably reduced in patients with S. aureus compared with those without (log rank p < 0.001). The type of surgery (repair vs. replacement) did not emerge as a risk factor for late mortality and reoperation. Seventeen patients underwent mitral reoperation during the follow-up. The 5- and 10-year freedom from reoperation was 94.7% and 91.8%, respectively. Conclusions: Active mitral valve endocarditis remains a life-threatening disease with impaired survival. While lesion characteristics influenced surgical decision-making and intraoperative management, their impact on long-term survival and freedom from reintervention appears to be moderated by other factors such as infecting pathogens and patient comorbidities.

Surgical repair and replacement for native mitral valve infective endocarditis

AIMS

The clinical benefits of mitral valve repair over replacement in the setting of mitral infective endocarditis are not clearly established.

METHODS

Data of patients who underwent cardiac surgery for infective endocarditis over a 20-year period (2001-2021) at two cardiac centres were reviewed. Among them, 282 patients underwent native mitral valve surgery and were included in the study. Nearest-neighbour propensity-score matching was performed to account for differences in patients' profile between the repair and replacement subgroups.

RESULTS

Mitral valve replacement was performed in 186 patients, while in 96 cases patients underwent mitral valve repair. Propensity match analysis provided 89 well matched pairs. Mean age was 60 ± 15 years; 75% of the patients were male. Mitral valve replacement was more commonly performed in patients with involvement of both mitral leaflets, commissure(s) and mitral annulus. Patients with lesion(s) limited to P2 segment formed the majority of the cases undergoing mitral valve repair. There was no difference in terms of microbiological findings. In-hospital mortality was 7% with no difference between the repair and the replacement cohorts. Survival probabilities at 1, 5 and 10 years were 88%, 72% and 68%, respectively after mitral repair, and 88%, 78% and 63%, respectively after mitral replacement (log-rank P  = 0.94).

CONCLUSIONS

Mitral valve repair was more commonly performed in patients with isolated single leaflet involvement and provided good early and 10-year outcomes. Patients with annular disruption, lesion(s) on both leaflets and commissure(s) were successfully served on early and mid-term course by mitral valve replacement.

Microbiological etiology in prosthetic valve endocarditis: A nationwide registry study

BACKGROUND

Prosthetic valve endocarditis (PVE) is a feared complication after heart valve surgery. Studies on differences in bacteriology in various types of PVE are limited.

OBJECTIVES

This study aimed to investigate the microbiology of PVE depending on the type of prosthetic valve and timing of diagnosis.

METHODS

A retrospective study based on the Swedish Registry on Infective Endocarditis focusing on PVE was conducted. The cohort was divided into mechanical and bioprosthetic valves; into endocarditis localization in the aortic, mitral, or tricuspid valve; and into early and late PVE. The microbiology in these groups was compared. Predictors of Staphylococcus aureus as the cause of PVE were examined by multivariable logistic regression.

RESULTS

A total of 780 episodes of PVE in 749 patients were compared regarding the distribution of causative microbiological agents. The most common agents included alpha-hemolytic streptococci (29%), S. aureus (22%), enterococci (14%), coagulase-negative staphylococci (CoNS) (12%), and Cutibacterium acnes (6%). S. aureus was more commonly found on mechanical valves compared to bioprosthetic ones (36% vs. 17%, p < 0.001) whereas alpha-hemolytic streptococci, enterococci, and CoNS were more common on bioprosthetic valves. There were no significant differences in the microbiology of PVE affecting mitral or aortic valves or in cases of early and late PVE. Predictors for S. aureus as the cause of PVE were end-stage renal disease, intravenous drug use, mechanical valve, and tricuspid localization of endocarditis.

CONCLUSIONS

The type of prosthetic heart valve is associated with the causative pathogen. Patients with mechanical valves are more likely to have PVE caused by S. aureus.

Aortic Biological Prosthetic Valve Dysfunction Secondary to Endocarditis: Is Percutaneous Valve-in-Valve an Option?

We present the case of a 69-year-old man with an aortic biological prosthetic valve. In May 2019, the patient experienced increasing dyspnea and fatigue: A diagnosis of prosthetic aortic valve dysfunction was made, leading to severe valvular insufficiency. The dysfunction of the prosthetic valve seemed to be linked to a previous infective endocarditis: after ruling out active endocarditis, the patient was treated with an off-label valve-in-valve transcatheter aortic valve implantation.

Mitral Valve Infective Endocarditis after Trans-Catheter Aortic Valve Implantation

Scarce data exist on mitral valve (MV) infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI). This multicenter study included a total of 579 patients with a diagnosis of definite IE after TAVI from the IE after TAVI International Registry and aimed to evaluate the incidence, characteristics, management, and outcomes of MV-IE after TAVI. A total of 86 patients (14.9%) had MV-IE. These patients were compared with 284 patients (49.1%) with involvement of the transcatheter heart valve (THV) only. Two factors were found to be associated with MV-IE: the use of self-expanding valves (adjusted odds ratio 2.49, 95% confidence interval [CI] 1.23 to 5.07, p = 0.012), and the presence of an aortic regurgitation ≥2 at discharge (adjusted odds ratio 3.33; 95% CI 1.43 to 7.73, p <0.01). There were no differences in IE timing and causative microorganisms between groups, but surgical management was significantly lower in patients with MV-IE (6.0%, vs 21.6% in patients with THV-IE, p = 0.001). All-cause mortality rates at 2-year follow-up were high and similar between patients with MV-IE (51.4%, 95% CI 39.8 to 64.1) and patients with THV-IE (51.5%, 95% CI 45.4 to 58.0) (log-rank p = 0.295). The factors independently associated with increased mortality risk in patients with MV-IE were the occurrence of heart failure (adjusted p <0.001) and septic shock (adjusted p <0.01) during the index hospitalization. One of 6 IE episodes after TAVI is localized on the MV. The implantation of a self-expanding THV and the presence of an aortic regurgitation ≥2 at discharge were associated with MV-IE. Patients with MV-IE were rarely operated on and had a poor prognosis at 2-year follow-up.

Staphylococcus aureus native mitral valve endocarditis associated with bed bug bites - A case report and review of the literature

Staphylococcus aureus is a leading cause of community acquired bacteremia and infective endocarditis. S. aureus is a part of the normal skin flora in approximately one third of the human population. Infective endocarditis due to S. aureus can cause several complications and is associated with increased mortality. A 48-year-old female with no significant medical history presented with S. aureus bacteremia and native mitral valve endocarditis. Multiple cutaneous skin lesions were identified, which she reported were due to recent bed bug bites. No source of infection was found except for the skin lesions. Her hospital course was complicated by pulmonary and cerebral septic emboli, left pleural empyema, and acute renal injury. We suspected the bed bug skin bites were the most likely source of bacteremia. Bed bugs carry many human pathogens but have not been shown to be a competent vector. We did not find any literature on endocarditis associated with bed bug bites; thus, our case will be a novel finding.

Surgery Is Underused in Elderly Patients With Left-Sided Infective Endocarditis: A Nationwide Registry Study

Background

Infective endocarditis is associated with higher mortality in elderly patients, but the role of surgery in this group has not been fully evaluated. The aim of this study was to assess outcomes of left‐sided infective endocarditis in elderly patients and to determine the influence of surgery on mortality in the elderly.

Methods and Results

A nationwide retrospective study was performed of 2186 patients with left‐sided infective endocarditis recorded in the SRIE (Swedish Registry of Infective Endocarditis), divided into patients aged <65 years (n=864), 65 to 79 years (n=806), and ≥80 years (n=516). Survival analysis was performed using the Swedish National Population Registry, and propensity score matching was applied to assess the effect of surgery on survival among patients of all ages. The rate of surgery decreased with increasing age, from 46% in the <65 group to 6% in the ≥80 group. In‐hospital mortality was 3 times higher in the ≥80 group compared with the <65 group (23% versus 7%) and almost twice that of the 65 to 79 group (12%). In propensity‐matched groups, the mortality rate was significantly lower between the ages of 55 and 82 years in patients who underwent surgery compared with patients who did not undergo surgery. Surgery was also associated with better long‐term survival in matched patients who were ≥75 years (hazard ratio, 0.36; 95% CI, 0.24–0.54 [P<0.001]).

Conclusions

The proportion of elderly patients with infective endocarditis who underwent surgery was low compared with that of younger patients. Surgery was associated with lower mortality irrespective of age. In matched elderly patients, long‐term mortality was higher in patients who did not undergo surgery, suggesting that surgery is underused in elderly patients.

Native Mitral Valve Infective Endocarditis From Flossing: A Case Report and Emergency Department Management

Infective endocarditis (IE) is a rare, elusive disease, carrying a 10%-30% mortality. Requiring a high index of suspicion, IE affects damaged native valves and prosthetic valves. While there are a number of inherent risk factors that predispose patients to IE, dental work in the preceding six weeks is often a culprit of disease, colonizing damaged native mitral valves with Streptococcus viridans species. Traditionally, flossing has been suggested to be protective against IE. We present a case of S. gordonii subacute IE on a regurgitant native mitral valve secondary to vigorous flossing.

Incidence of infective endocarditis caused by viridans group streptococci in Sweden - effect of cessation of antibiotic prophylaxis in dentistry for risk individuals

Introduction

In October 2012, the Swedish Medical Products Agency published new recommendations for the cessation of prophylactic antibiotics in dentistry for the prevention of infective endocarditis (IE). Previously, 2 g of amoxicillin per os would be administered 1 h before invasive dental procedures to patients with valve prosthesis, complicated heart valve disease, and to those with previous endocarditis.

Objectives

The aim of this study was to evaluate whether the total incidence of IE caused by oral viridans group streptococci (VGS) or IE caused by staphylococci, increased in Sweden after the introduction of the new recommendations.

Methods

The incidence of IE in Sweden before and after October 2012 was calculated and compared using an interrupted time series analysis. Separate analyses were conducted for the total incidence of IE, and IE caused by VGS or Staphylococcus aureus. Cases of IE were identified using the Swedish national registry of IE, which has existed since 1995 and contains data from all Swedish hospital clinics specialising in infectious disease. All cases with hospital admission date from the 1^st of Jan 2008, to the 31^st of Dec 2017 were included. The incidence calculations were corrected for annual changes in population size using data from the Swedish government agency Statistics Sweden.

Results

The results show no statistically significant increase in the slope of the trend line of the total incidence of IE, IE caused by VGS or S. aureus in the Swedish general population after October 2012, compared to before.

Conclusion

The results suggest that the recommended cessation of prophylactic antibiotics for the prevention of IE in dentistry has not led to an increased incidence of IE caused by oral streptococci among the Swedish population.