Risk of Embolism and Death in Infective Endocarditis: Prognostic Value of Echocardiography

The relationship between the initiation of antimicrobial therapy and the incidence of stroke in infective endocarditis: an analysis from the ICE Prospective Cohort Study (ICE-PCS)

BACKGROUND

Embolic events to the central nervous system are a major cause of morbidity and mortality in patients with infective endocarditis (IE). The appropriate role of valvular surgery in reducing such embolic events is unclear. The purpose of this study was to determine the relationship between the initiation of antimicrobial therapy and the temporal incidence of stroke in patients with IE and to determine if this time course differs from that shown for embolic events in previous studies.

METHODS

Prospective incidence cohort study involving 61 tertiary referral centers in 28 countries. Case report forms were analyzed from 1437 consecutive patients with left-sided endocarditis admitted directly to participating centers.

RESULTS

The crude incidence of stroke in patients receiving appropriate antimicrobial therapy was 4.82/1000 patient days in the first week of therapy and fell to 1.71/1000 patient days in the second week. This rate continued to decline with further therapy. Stroke rates fell similarly regardless of the valve or organism involved. After 1 week of antimicrobial therapy, only 3.1% of the cohort experienced a stroke.

CONCLUSIONS

The risk of stroke in IE falls dramatically after the initiation of effective antimicrobial therapy. The falling risk of stroke in patients with IE as a whole precludes stroke prevention as the sole indication for valvular surgery after 1 week of therapy.

Modern epidemiology, prophylaxis, and diagnosis and therapy for infective endocarditis

Infective endocarditis (IE) is a rare disease. Although its incidence and bacteriology have remained relatively stable in outpatient populations without injection drug use, health care-associated infections, particularly with staphylococcus, are becoming more common. Large-scale prospective clinical trials are unavailable to guide strategies for preventing IE, timing surgical intervention, and avoiding complications. We continue to rely on new data from smaller series and large observational databases to track these changes and improve care of patients. At the present time, there are several controversies regarding best practices in IE. In this review, we address the following questions: What is the future of recommendations for antibiotic prophylaxis against IE? How should we best use echocardiography in diagnosis, management and follow up of IE patients? What are the most appropriate antibiotic regimens for different patients in the face of shifting microbiology and demographics? Lastly, how should patients be selected for early surgery to avoid the complications of these infections?

Characteristics and analysis of risk factors for mortality in infective endocarditis

OBJECTIVE

The aim of our study was to establish the etiology of and risk factors for infective endocarditis (IE) and determine the prognostic factors for adverse outcome during hospital admission in a Turkish population.

MATERIAL AND METHODS

Between January 2002 and January 2004, the clinical and laboratory features of 112 consecutive adult patients (>18 years) with diagnosis of IE who were referred to the infectious diseases clinics/departments of 17 teaching hospitals in Turkey were evaluated. Cases of IE were defined according to the modified Duke Criteria. Mortality was defined as death occurring within 30 days or during hospital stay period. Univariate and multivariate analyses were performed to predict the factors related to fatal outcome.

RESULTS

A total of 112 consecutive patients presented with 101 definite and 11 probable IE episodes were defined according to the modified Duke Criteria. The mean age was 45.2+/-19.9. Fifty percent of the patients were male. Ninety (60.4%) of the 112 patients had risk factors for IE and 48 (42.9%) of them had >or=2 risk factors. On the other hand, 49.1% of patients had cardiac risk factors. Blood cultures were positive in 94 (83.9%) cases. Staphylococci were the most common agents (50.0%), followed by streptococci (28.7%) and enterococci (16.0%). Native cardiac valves were detected in 93 (83%) of the episodes of suspected IE. Valvular involvement was present in 103 (92%) patients; the mitral valve, alone or in combination with other valves, was affected in 70 (62.5%) of the patients. Echocardiography detected vegetations in 105 patients (93.8%). The mortality rate was 28.6%. Three factors were independently associated with mortality: haemodialysis OR: 14.5 (95% CI: 1.5-138.2), mobile vegetation OR: 4.8 (95% CI: 1.5-15.4) and mental alteration OR: 4.1 (95% CI: 1.1-15.6).

CONCLUSION

Mortality is still high in IE. Our data indicate that patients with altered mental status, mobile vegetation, or on haemodialysis had poorer prognosis.

Candida dubliniensis in Recurrent Polymicrobial Tricuspid Endocarditis

This report describes a successful operative case of tricuspid infective endocarditis in an IV drug user. Despite cessation of IV drug use, there were further recurrences. Six different microorganisms with multiple portals of entry were identified, including one episode of fungal endocarditis, To our knowledge, this is the first case of recurrent infective endocarditis involving Candida dubliniensis in an HIV-negative patient.

Short-term and one-year outcome of infective endocarditis in adult patients treated in a Finnish teaching hospital during 1980-2004

Background

Previous studies on factors predicting the prognosis of infective endocarditis have given somewhat conflicting results. Our aim was to define the factors predicting the outcome of patients treated in a Finnish teaching hospital.

Methods

A total of 326 episodes of infective endocarditis in 303 patients treated during 1980–2004 were evaluated for short-term and 1-year outcome and complications.

Results

Infection of 2 native valves and the occurrence of neurological complications, peripheral emboli, or heart failure significantly predicted both in-hospital and 1-year mortality, while age ≥65 years or the presence of a major criterion or vegetation on echocardiography predicted death within 1 year. A significant trend was observed between the level of serum C-reactive protein (CRP) on admission and both the short-term and 1-year outcome. In the patients who had CRP values ≥100 mg/l on admission, the hazard ratio for in-hospital death was 2.9-fold and the hazard ratio for 1-year death was 3.9-fold as compared to those with lower CRP values. Male sex and age < 64 years significantly predicted a need for both in-hospital and 1-year surgery, as did the development of heart failure or the presence of a major criterion or vegetation on echocardiography. Peripheral emboli were associated with a need for in-hospital surgery, while Streptococcus pneumoniae as the causative agent or infection of 2 native valves predicted a need for surgery within 1 year from admission.

Conclusion

Some of the factors (e.g. heart failure, neurological complications, peripheral emboli) predicting a poor prognosis and/or need for surgery were the same observed in previous studies. A new finding was that high CRP values (≥100 mg/l) on admission significantly predicted both short-term and 1-year mortality.

Treatment of Endocarditis: A Decade of Experience

BACKGROUND

Endocarditis represents a small proportion of cardiovascular disease but is associated with high mortality. Previous studies have reported a range of outcomes, and determinants of mortality remain poorly defined.

METHODS

The goal of this retrospective study was to identify independent variables for early and late mortality in 364 consecutive patients with endocarditis over a 10-year period.

RESULTS

The mean age of patients was 48.2 years, 35% had a history intravenous drug use, 19.8% were reoperative, and 93% had native valve endocarditis. Fever (68%) and fatigue (36%) were the most common presenting symptoms, and congestive heart failure (52%), embolization (45%), and uncontrolled sepsis (36%) were the most common indications for surgery. Overall survival at discharge, 1, 5, and 10 years was 87%, 76%, 55%, and 31%, respectively. Survival at discharge, 5, and 10 years was 91%, 69%, and 41% for surgical patients and 85%, 60%, and 31% for medically treated patients, respectively. Surgery was associated with improved short-term and long-term survival (p < 0.0.01). Independent predictors of early death were hemodynamic instability (p = 0.013) and age older than 55 years (p < 0.025). Medical treatment (p = 0.005), age older than 55 years (p = 0.032), institution (p < 0.001), New York Heart Association functional class III or IV (p = 0.002), and hemodynamic instability (p = 0.044) were predictive of late death.

CONCLUSIONS

Short-term and long-term mortality from endocarditis remains high, although surgically treated patients had improved survival. Differing outcomes from two geographically similar institutions highlight the limitations of extrapolating risk factors between disparate patient populations.

Characteristics and regional variations of group D streptococcal endocarditis in France

The proportion of infective endocarditis (IE) caused by group D streptococci (GDS; formerly Streptococcus bovis) increased markedly in France, to account for 25% of all cases of IE by 1999. In an attempt to explain this phenomenon, a comparative analysis of GDS and oral streptococci (OS) causing IE was performed. This study was based on data collected from a large cross-sectional population-based survey that was conducted in 1999. In total, 559 cases of definite IE were recorded, of which 142 involved GDS and 79 involved OS. Patients with GDS IE were older (62.7 vs. 56.6 years, p 0.01) and had a history of valve disease less frequently than did patients with OS IE (33.8% vs. 67.1%, p <0.0001). At-risk procedures for IE were performed less frequently in patients with GDS than in patients with OS (14.8% vs. 24.1%, p 0.08), but co-morbidities were more frequent in the GDS group (59.9% vs. 32.9%, p 0.0001). Diabetes, colon diseases and cirrhosis were also more frequent in the GDS group (p 0.006, p <0.0001 and p 0.08, respectively). Rural residents accounted for 31.0% of the GDS group, but for only 15.2% of the OS group (p 0.001). Likewise, the proportion of GDS IE was higher in regions with mixed (urban and rural) populations (Franche-Comté 81.8%, Marne 68.7%, Lorraine 70.3% and Rhône-Alpes 65.3%) than in exclusively urban regions (Paris and Ile de France 58.0%). Further investigations are required to elucidate the link in France between the incidence of GDS IE, rural residency and nutritional factors.

Granulicatella elegans native valve infective endocarditis: case report and review

Granulicatella elegans is a fastidious organism that is rarely implicated as a cause of infective endocarditis. Here, we describe a patient with mitral valve prolapse who developed G. elegans endocarditis. The organism was isolated from blood cultures and the patient had mitral valvuloplasty and repair, and completed a course of 6 weeks of intravenous antibiotics with no sequela.

Aortic valve endocarditis: is there an optimal surgical timing?

PURPOSE OF REVIEW

Patients with aortic valve infective endocarditis are likely to undergo surgery during the active phase of the disease. The indication and best timing for surgery, however, are still debated. The present review discusses the benefits and risks of early surgery in aortic endocarditis.

RECENT FINDINGS

Patients with acute aortic regurgitation and clinical or echocardiographic signs of poor tolerance require urgent surgery. Other indications for early surgery include severe perivalvular involvement and high embolic risk. Echocardiography plays an important role in the assessment of embolic risk and helps in choosing the best therapeutic strategy. Several recent studies have identified high-risk subgroups of patients that, without surgery, face poor prognosis. Patients with complicated endocarditis, particularly those with congestive heart failure, will benefit most from surgery. Patients with prosthetic valve endocarditis and cerebral complications represent specific subgroups in which surgical decision is more difficult.

SUMMARY

Patients with severe aortic leaflet destruction and congestive heart failure, patients with perivalvular extension or uncontrolled infection, and patients with high embolic risk have poor outcome under medical therapy. Early surgery is necessary in all such patients with 'complicated' endocarditis, unless severe comorbidity is present.

Importance of surgical timing on postoperative outcome in patients with native valve acute endocarditis

BACKGROUND

The present study was undertaken to establish whether surgical outcome could be influenced by surgical timing in patients affected by native valve endocarditis (NVE).

METHODS

From March 2002 to December 2004, 19 patients underwent surgical operation for NVE. Aortic valve replacement (AVR) was performed in ten patients (53%), mitral valve repair (MVRep) was performed in five patients (26%) and multivalvular procedures were performed in the remaining four patients (21%). In three patients (15.5%), emergency surgery was required for refractory congestive heart failure, urgent surgery was necessary in ten patients [in six patients (31%) for paravalvular abscess, in three patients (15.5%) for macrovegetations and in one patient (6%) for systemic embolism, respectively], five patients (26.3%) with isolated valve incompetence underwent elective surgery, whereas delayed surgery was reserved for one patient (6%) because of pre-operative embolic stroke.

RESULTS

There were no surgical procedure, cardiac or infectious related deaths at 30 days in the entire group. One patient died from an intravenous overdose. Follow-up was 100% complete in the 18 hospital survivors and ranged from 4 to 37 months (mean 14.2 +/- 10 months). There were no late death, recurrence of endocarditis, or re-operation at follow-up.

CONCLUSIONS

The surgical results for NVE are excellent if surgical timing criteria are correctly applied during the acute phase of the infectious process. Immediate surgical correction is required when rapid hemodynamic deterioration occurs whereas a more aggressive surgical approach appears to be advisable in the case of paravalvular abscess, macrovegetations or systemic embolism. Delayed surgery is recommended when pre-operative stroke develops.

Clinical manifestations and outcome in Staphylococcus aureus endocarditis among injection drug users and nonaddicts: a prospective study of 74 patients

BACKGROUND

Endocarditis is a common complication in Staphylococcus aureus bacteremia (SAB). We compared risk factors, clinical manifestations, and outcome in a large, prospective cohort of patients with S. aureus endocarditis in injection drug users (IDUs) and in nonaddicts.

METHODS

Four hundred and thirty consecutive adult patients with SAB were prospectively followed up for 3 months. Definite or possible endocarditis by modified Duke criteria was found in 74 patients: 20 patients were IDUs and 54 nonaddicts.

RESULTS

Endocarditis was more common in SAB among drug abusers (46%) than in nonaddicts (14%) (odds ratio [OR], 5.12; 95% confidence interval [CI], 2.65-9.91; P < 0.001). IDUs were significantly younger (27 +/- 15 vs 65 +/- 15 years, P < 0.001), had less ultimately or rapidly fatal underlying diseases (0% vs 37%, P < 0.001) or predisposing heart diseases (20% vs 50%, P = 0.03), and their SAB was more often community-acquired (95% vs 39%, P < 0.001). Right-sided endocarditis was observed in 60% of IDUs whereas 93% of nonaddicts had left-sided involvement (P < 0.001). An extracardiac deep infection was found in 85% of IDUs and in 89% of nonaddicts (P = 0.70). Arterial thromboembolic events and severe sepsis were also equally common in both groups. There was no difference in mortality between the groups at 7 days, but at 3 months it was lower among IDUs (10%) compared with nonaddicts (39%) (OR, 5.73; 95% CI, 1.20-27.25; P = 0.02).

CONCLUSION

S. aureus endocarditis in IDUs was associated with as high complication rates including extracardiac deep infections, thromboembolic events, or severe sepsis as in nonaddicts. Injection drug abuse in accordance with younger age and lack of underlying diseases were associated with lower mortality, but after adjusting by age and underlying diseases injection drug abuse was not significantly associated with mortality.

Surgical Management of Infective Endocarditis: Early Predictors of Short-Term Morbidity and Mortality

BACKGROUND

Infective endocarditis is a diagnostic and therapeutic challenge that ultimately requires surgical intervention in 20% of all cases. Early determinants of morbidity and mortality in this high risk population are not well described.

METHODS

The aim of this study was to determine preoperative clinical, microbiological, electrocardiographic, and echocardiographic variables that predicted the need for permanent pacemaker implantation and in-hospital death in a surgical cohort of patients with active infective endocarditis.

RESULTS

We identified 91 patients (61 males and 30 females, mean age 58 +/- 16 years) who underwent surgical intervention for active culture-positive infective endocarditis as defined by the Duke criteria. Native valve infective endocarditis was present in 78 (85.7%) and prosthetic valve endocarditis in 13 (14.3%) of cases. The aortic valve was infected in 61 (67.0%), the mitral in 35 (38.5%), and multiple valves in 8 patients (8.8%). The most common indication for surgical intervention was intractable heart failure. Twenty-two patients (24.2%) required pacemakers, while there were 14 (15.4%) in-hospital deaths. In age-adjusted and gender-adjusted analyses, the presence of left bundle branch block on preoperative electrocardiogram (ECG) and presence of depressed left ventricular systolic function (ejection fraction [EF] < 50%) predicted the need for a permanent pacemaker implantation, while the presence of depressed left ventricular function predicted in-hospital mortality.

CONCLUSIONS

Preoperative ECG findings of left bundle branch block and reduced left ventricular function may allow for early risk stratification of this high risk population.

Complications of native and prosthetic valve infective endocarditis: Update in 2006

Infective endocarditis is a rare disease associated with significant morbidity and mortality. In the past decades, there have been significant improvements in the management of infective endocarditis. Complications are frequent and include heart failure, embolic episodes, periannular complications, and central nervous system events. Surgical therapy has been fundamental in the reduction of mortality in complicated cases. This paper is an overview of the main complications of native and prosthetic infective endocarditis and its treatment.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.