Clinical approach to infective endocarditis

Multi-valvular endocarditis

OBJECTIVE

Seventy-seven cases of native valve infective endocarditis as determined by the Duke criteria, were reviewed to determine the incidence and clinical features of multi-valvular endocarditis.

METHODS

Fourteen of 77 patients (18%) had multi-valvular endocarditis most commonly involving the mitral and aortic valves. Staphylococcus aureus (43%) and viridans streptococci (36%) were the most common organisms causing multi-valvular endocarditis.

RESULTS

Definite or probable vegetations were found in 50% of the patients by two-dimensional transthoracic echocardiograph and/or transesophageal echocardiograph, and possible vegetations were detected in 21%. The overall mortality in our series was 21%; 29% underwent valve replacement and 50% were treated medically. The major complications of multi-valvular endocarditis were congestive heart failure (64%), acute renal failure (50%), embolic events (21%), and splenic abscess/infarcts (21%).

CONCLUSIONS

Our data suggests complications of multi-valvular endocarditis, compared with uni-valvular endocarditis are similar except for heart failure. Heart failure is statistically more common in multi-valvular endocarditis (P < or = 0.002).

Are blood and valve cultures predictive for long-term outcome following surgery for infective endocarditis?

OBJECTIVE

To evaluate whether perioperative bacteria identification in blood and/or in valve cultures can predict early and late outcome of surgery for infective endocarditis, a retrospective study was performed.

METHODS

Between January 1978 and December 1998, 232 patients, 79 (34.1%) female and 153 (65.9%) male with mean age of 44. 95+/-1.03 years (range 8-79) underwent surgery for infective endocarditis on a native (162 cases) or prosthetic (70 cases) valve. Patients were divided into three groups according to the perioperative x of microbiological tests: Group A: patients with preoperative positive blood cultures (83 cases); Group B: patients with positive valve cultures (35 cases); Group C: patients with negative blood and valve cultures (114 cases). Categorical values were compared by chi(2) analysis, whereas continuous data were compared by ANOVA and Bonferroni correction for post hoc comparisons. Analysis of late survival and complications was performed with Kaplan-Meier and Log Rank test. Late mortality, reoperation, perivalvular leak, recurrence of infection were considered as treatment failure. All data were presented as mean+/-standard error.

RESULTS

Hospital mortality was 10.8% (9/83) in Group A, 8.6% (3/35) in Group B, and 14.9% (17/114) in Group C (P=0.52; not significant (NS)). Ten-year survival was 62.7+/-8% in Group A, 43.9+/-19% in Group B and 62.7+/-7% in Group C (P=0.38; NS). Ten-year freedom from reoperation was 85.2+/-6% in Group A, 37.9+/-20% in Group B and 80+/-6% in Group C (P=0.0034). Ten-year freedom from treatment failure was 56.3+/-8% in Group A, 31.6+/-16% in Group B and 55. 3+/-7% in Group C (P=0.46; NS).

CONCLUSIONS

Positive blood and tissue cultures are not predictive for hospital mortality and late treatment failure in patients with infective endocarditis. Positive valve cultures, a common finding in patients with staphylococcal endocarditis, are predictive for a higher risk of reoperation.

Compiling the identifying features of bacterial endocarditis. Vague clues may point to this dangerous infection

Bacterial endocarditis is a life-threatening disease. Before the advent of antibiotics, its mortality rate was nearly 100%, but with today's diagnostic and therapeutic advances, it can be successfully managed in most cases. In this article, Drs Harris and Steimle explain the changes that occur when someone, who usually has an underlying cardiac defect, contracts bacteremia with an organism likely to adhere to heart valve surfaces. They describe risk factors, clinical presentations, identification of causative organisms, and empirical and specific therapy. A case report illustrates the many possible manifestations of the disease.

The changing face of endocarditis: report of a series of cases

A 67-year-old man presented with a sudden onset right homonymous hemianopia associated with a swinging pyrexia and a new early diastolic parasternal murmur. He had had a Bjork–Shiley aortic valve replacement 2 years previously for symptomatic aortic stenosis with a transvalvular gradient of 80 mmHg and had been well thereafter.

Computed tomography scan of the brain showed a left occipital infarct (Figure 1), C-reactive protein was 51 mg/litre (normal <10 mg/litre), blood cultures consistently grew Candida parafilaris, and treatment with intravenous liposomal amphotericin and flucytocine was started the day the first positive culture was obtained. Transoesophageal echocardiography did not demonstrate vegetations, but did show a periprosthetic aortic incompetent leak.

On day 11 the aortic prosthesis was removed and replaced because of worsening aortic incompetence. Direct inspection of the prosthesis demonstrated a vegetation on the sewing ring. The immediate postoperative recovery period was complicated by complete heart block requiring insertion of a permanent pacemaker after an initial phase of pericardial pacing.

The intravenous antifungals were discontinued after 37 days of treatment and the patient commenced on lifelong oral fluconazole. At discharge on day 42 the patient was well and apyrexial with C-reactive protein less than 10 mg/litre.

Prosthetic valve endocarditis leading to valve replacement: a case study

Infective endocarditis (IE) is a pathologic condition of native or prosthetic heart valves or endocardium, which may result in valve destruction and congestive heart failure. It occurs more frequently in men than in women, and there is an increased trend in the elderly. The following conditions predispose patients to IE: congenital and rheumatic heart disease, calcification or stenosis of a valve, prosthetic valve surgery, a previous episode of endocarditis, poor dentition, parenteral drug abuse, and placement of intravascular lines or devices. Effective treatment frequently involves a combination of intense antibiotic therapy and surgical repair. Risk of death from IE is related to age over 60, diagnosis of staphylococcal infection, involvement of an aortic or prosthetic valve, and the presence of any of the following sequelae of endocarditis: congestive heart failure, embolic phenomenon, and neurologic deficit. Clinicians should suspect endocarditis in patients presenting with fever of unknown origin and who are at risk for endocarditis. Timely evaluation with transthoracic or transesophageal echocardiography may identify patients in the early stages of endocarditis and direct the patient to definitive therapy. Early treatment of native and prosthetic valve endocarditis may decrease its overall morbidity and mortality. This case study illustrates some of the challenges in effectively managing prosthetic valve endocarditis.

Recognition, management and prophylaxis of endocarditis

Infective endocarditis (IE) remains a disease with high morbidity and mortality. In recent years, a higher frequency of IE has been observed in the elderly, in intravenous drug users and in patients with prosthetic valves. The diverse manifestations of this disease demand a high degree of suspicion from the practitioner, in order to make an early diagnosis. Advances in and increasing use of echocardiography (especially transoesophageal) allow us to identify valvular changes earlier and more precisely. The use of the new Duke's diagnostic criteria, based on clinical manifestations and microbiological and echocardiographic findings, facilitates the diagnosis and categorisation of IE. An increase in staphylococci and other problem pathogens, such as penicillin-resistant streptococci, enterococci resistant to beta-lactams, aminoglycosides and methicillin-resistant staphylococci has been observed. Important changes have also taken place in the management of IE. There is a clear trend towards the use of shorter treatment courses, oral and once-daily regimens and outpatient programmes, all of which aim to reduce costs and provide patients with improved quality of life. Antibiotic prophylaxis for the prevention of IE is still controversial. In the past few years more rational regimens have been used, and indications are now more precise. In spite of all this, however, few cases are prevented and patient compliance to the prophylaxis regimens remains low.