© Borgis - New Medicine 3/2003, s. 53-56
Stanislaw Ostrowski, Janusz Zaslonka, Alicja Iwaszkiewicz, Anna Kosmider, Michal Wojciechowski, Slawomir Jander, Radoslaw Zwolinski, Leszek Markuszewski, Andrzej Walczak
Infective endocarditis – surgical treatment in subjects 65 years old and older
Department of Cardiac Surgery, Cardiology Institute, Medical University of Lodz, Poland
Head: prof. Janusz Zaslonka, MD, PhD
Summary
Background: The objective of the study was to evaluate the results of surgical treatment of infective endocarditis in patients aged 65 and more who underwent operation in the Department of Cardiac Surgery, Medical University of Lodz, in 2001 and 2002.
Material and methods: Among all 31 patients operated on during this period, 23% were aged 65 and more (3 men and 4 women). In 2 cases infective endocarditis was associated with a prosthetic valve. Negative blood culture was present in 5 patients. Every patient had undergone at least one cycle of antibiotic therapy before the intervention. Four patients were in the NYHA III/IV functional class before surgery, and one had had an ischaemic stroke. Transoesophageal echocardiography was used as the main diagnostic method.
Results: After surgery, low cardiac output syndrome developed in 3 patients, resulting in 2 deaths (29% compared to 20% mortality rate in patients aged less than 65).
Conclusions: Cardiac surgery in infective endocarditis is very risky, irrespective of age, especially in patients having already had valve prosthesis, when a possibility of a redo operation must be considered. Higher mortality in the elderly is due to their general condition. In these patients many other causes are suspected of contributing the general deterioration in condition which delays the correct treatment.
Background
Infective endocarditis (IE) is a severe disease and, if not treated intensively, almost always fatal. Usually among those who are referred to the cardiac surgeon are the most severely ill patients, in an advanced state of the disease and without a good response to medical treatment. In these cases, surgery is often the last chance for effective therapy. Patients aged 65 years or older are a specific group. Due to their generally poorer health condition, IE itself and any surgical procedure place them in great jeopardy.
The aim of this study is an assessment of early (up to 60 days) and longer-term results of surgical treatment of IE in elderly patients, in the Department of Cardiac Surgery, Institute of Cardiology, Medical University of Lodz.
Material and methods
In 2001 and 2002, 31 patients (7 women and 24 men) were operated upon due to IE. Their ages ranged from 29 to 75 years, with a median of 51 years. Patients of 65 years or older were extracted from this population and included in the study group. This numbered 7 patients (23%), including 4 women and 3 men, at a mean age of 68.8 years.
Data analysis
The following clinical data were analyzed: criteria of reference for surgery, aetiolo gy of IE, type of surgical procedure, antibiotic therapy, and early postoperative course (up to 60 days).
Pathognomonic features of IE observed in transoesophageal echocardiography and positive blood and tissue (valve) cultures were taken as the major diagnostic criteria of IE. The following clinical features were taken as minor criteria of IE: body temperature higher than 38ş centigrade, new heart murmur, embolic complications, immunological symptoms, and others included in the Duke University definition of IE (1). During the early postoperative period, rates of mortality, morbidity and recurrence of infection were assessed. The data on hospitalisation were collected on the basis of a clinical record review. The follow-up data were gathered from the outpatient clinic records at the Department of Cardiac Surgery, where 2 patients have been followed regularly. Three out-of-area patients are followed by their regional clinics.
The patients
Two patients developed IE on previously-implanted heart valve prostheses; on a mitral in one case and on both mitral and aortic in another. Both of them had also had heart pacemakers implanted. These 2 patients died in the early postoperative period. The third patient from the study group suffered from myxoma of the mitral valve, causing its dysfunction, and had a history of coronary angiography. The next patient had a floppy valve syndrome with significant mitral regurgitation. High levels of antistreptolysin reaction, reaching 1600 IU/ml, were observed in other 2 patients. One of them had a history of arthritis more than one year earlier. Furthermore, one of the patients has stayed in the care of the urologist due to benign hyperplasia of the prostate, and one of the female patients needed extraction of tooth roots.
On admission to the department, 4 of the patients (57%) presented with advanced circulatory insufficiency (III or IV NYHA class). As many as two of 7 patients (29%) developed IE on previously implanted mechanical heart valve prostheses (both cases fatal). In all 7 patients the infection was subacute, often with a history of several weeks or longer. Before admission to the department of cardiac surgery, 6 patients underwent at least one course of antibiotic therapy. One female patient was referred to the department before the completion of her first course of antibiotic therapy, due to active infective endocarditis (2).
In this group of patients the most frequent location of IE was the mitral valve – 6/7 (86%, including one patient with changes on both mitral and aortic valves). One of 7 patients developed IE on the aortic valve alone.
The indications for surgery were: circulatory insufficiency of III or IV NYHA class (4 patients), presence of large vegetations on heart valves which could potentially be a source of emboli (5 patients), severe bacteraemia not responding to antibiotic therapy (1 patient), dysfunction of previously-implanted mechanical heart valve prostheses (2 patients), embolic complications (1 patient) and valvular anulus abscess (1 patient).
The mitral valve was replaced in 5 patients, including 4 native valves and 1 mechanical prosthesis (Sorin-Biomedica). In these cases mechanical prostheses (St. Jude Medical, SJM) were implanted. In one patient an aortic native valve was replaced using an SJM prosthesis, and in one patient both mitral and aortic prostheses (Hall-Medtronic) were replaced using SJM prostheses.
As the adjuvant treatment, all patients were administered aggressive intravenous antibiotic therapy, selected and modified on the basis of repeated blood and tissue cultures.
Results
The early mortality rate in all patients operated on due to IE was 23% (7/31). In the study group it was even higher – 29% (2/7), whereas the mortality rate in patients under 65 years was 20% (5/24).
In 57% of patients over 65 years postoperative complications were observed, and the most frequent (43%) was low cardiac output syndrome (LCOS), which was the cause of death in 2 patients (29%). One patient developed atrial fibrillation.
In the early postoperative period a recurrence of IE was not observed in any patient.
In 5 patients in the early postoperative period, blood/valve cultures were negative. In one patient (who died after the operation) the culture yield was Pseudomonas aeruginosa. The blood culture yield of the patient with incomplete preoperative antibiotic therapy course was Enterococcus faecalis.
In all 5 patients who were discharged from the hospital in a good clinical state, without any evidence of reinfection, multiple blood cultures were negative.
The preoperative mean ejection fraction (EF) was 56.3% and postoperatively 53.6%.
Further follow-up has been continued in the outpatient clinic at the Department of Cardiac Surgery for one and half years (2 patients). The remaining 3 out-of-area patients are alive and their follow-up has been continued in their regional outpatient cardiac clinics.
Table 1. The Clinical characteristics of patients 65 years old or older, operated on due to IE, in 2001 and 2002.
| | J.K. | Z.F. | B.I. | S.M. | J.M. | D.K. | H.Z. |
| Sex | M | M | F | F | M | F | F |
| Age | 70 | 65 | 75 | 72 | 66 | 68 | 66 |
| Risk factors of IA | Post-AVR
Post-MVR
Pacemaker
Urological
procedures | Myxoma of mitral valveCoronary angiography | Floppy valveMitral insufficiency | Arthritis,ASR 400-1600 IU/mlOral sepsis | ASR>1600 IU/ml | | Post-MVR
Pacemaker |
| Valves involved | MV+AV
Prostheses | MV Native | MVNative | AV Native | MV Native | MV Native | MV Prosthesis |
| Bacteriology | Pseudomonas aeruginosa | - | - | - | - | Enterococcus faecalis | - |
| Course of IE | Subacute | Subacute | Subacute | Subacute | Subacute | Subacute | Subacute |
| Preoperative treatment | ATB | ATB | ATB | ATB | ATB | ATB (not completed) | ATB |
| Indications to surgery | NYHA IV
P.aeruginosa resistant to ATB
Big vegetationsEmbolic complications
Dysfunction of MV and AV prostheses | NYHA IVMyxoma and lesion of MV | NYHA III | NYHA IVBig vegetations | Big vegetations
MV lesion | Big vegetationsMV lesion | Big vegetationMV anular abscessDysfunction of MV prosthesis |
| Employed treatment | Re-MVR
Re-AVR
ATB | MV
RATB | MV
RATB | Oral cavity cure
AVRATB | MVR
ATB | MV
RATB | Re-MVR
Re-AVR |
| Outcome | LCOS
Death | LCOS
Discharged | AF
Discharged | Discharged | Discharged | Discharged | LCOS
death |
MV – mitral valve, AV – aortic valve, ATB – antibiotic therapy, MVR – mitral valve replacement, AVR – aortic valve replacement, re – redo, LCOS – low cardiac output syndrome, AF – atrial fibrillation, ASR – antistreptolysin reaction
Discussion
Surgical intervention in IE entails a high risk regardless of the patient´s age. The high mortality rate results mainly from difficulties in the timing of patient refferal to the surgeon. Frequently, the delay leads to significant progress of the disease and development of severe circulatory insufficiency and cachexy. Such a clinical state is a special challenge for the surgeon.
The prevalence of IE in the elderly population is still increasing. It is the consequence of a continuous increase in the mean human lifespan, an increasing number of patients over 65 after valve replacement procedures, and longer survival of patients with rheumatic valvular heart disease (3). The mineralization of valves and big vessels (4), as well as impaired blood circulation, connected with ageing, are conducive to the development of IE.
The risk attached to surgical treatment of IE in patients over 65 is significantly increased due to a general poorer health condition, concomitant diseases and reduced tolerance of surgery. The oligosymptomatic course and non-characteristic symptoms of IE (5) often make the diagnosis difficult and delay intervention which results in a decreased chance of success. All patients operated upon in our institution suffered from subacute IE, usually with a recurrent course and a low level of symptoms. A lack of high fever even during acute infection (3), difficulties in observing mood changes, and a commonly appearing decrease in effort tolerance, all of which are characteristic of this age, may not be sufficient by alarming signals for the general practitioner. Elderly persons suffer from many concomitant diseases, which on the one hand may mask symptoms of IE, and on the other hand, may increase the risk of infection and bacteriaemia through invasive diagnostic and therapeutic procedures. Among patients operated on because of IE in our institution, there was one who had previously undergone coronary angiography, which together with the coexistence of mitral valve myxoma might be the reason for the infection (6). Another patient stayed in the urologist´s care because of benign hyperplasia of the prostate – a disease leading to retention of urine and creating perfect conditions for the development of urinary tract infection and in consequence for bacteriaemia (3, 7). A similar situation takes place in postmenopausal women, in whom atrophic changes in the vaginal and urethral mucosa are conducive to colonization by bacteria and fungi (8). One must not forget neglect of oral hygiene, also common in our country in this age group, which is frequently the entry route for infection in IE. It is not rare that the surgeon must postpone the operation to give time for oral care in order to eliminate this evident source of infection. Infective endocarditis is particularly dangerous when it develops on a previously-implanted heart valve prosthesis (1, 7, 9). A poor response to medical treatment, rapidly progressing haemodynamic disorders, and a high mortality rate, place this form of IE at the front of the list of indications for quick surgical intervention (7, 10, 11).
In our study, a bacteriological examination occurred positive only in one case (14.3%). If blood cultures are properly performed they have up to 95% efficacy in the detection of pathogens. However, as many as 6 out of 7 patients from the study group had previously undergone at least one course of antibiotic therapy, and this probably made the cultures more difficult (3). Furthermore, in a department of cardiac surgery there are often no posssibilities for long waiting (sometimes even several weeks) for culture results, which would be necessary in cases of infection caused by certain strains. The strain of Pseudomonas aeruginosa grown from a blood culture of the patient with an infected heart valve prosthesis showed a significant degree of resistance to the majority of antibiotics, which is typical for this form of IE. Sepsis triggered off by this strain caused this patient´s death. In the remaining patients with negative cultures empirical antibiotic therapy was employed. It was based on evidence provided by studies on the prevalence of individual pathogens in Poland and in the region of Lodz (10, 14, 15).
The crucial role in the diagnosis of IE and assessment of its degree of severity played transoesophageal echocardiography. This shows a sensitivity of more than 80% and a specificity of 94% (1, 10, 16, 17). This examination seems to be indispensable while diagnosing IE developing on valve prostheses or perianular abscess, and for monitoring in case of a lack of response to medical treatment (1, 16).
The main direct cause of death in both patients from the study group was low cardiac output syndrome (18), which still remains a frequent and dangerous complication of cardiac surgery. It usually results from perioperative myocardial ischaemia and infarction or arrhythmias, but may also be caused by preoperative myocardial injury (19, 20). In most cases, effective antibiotic therapy minimizes the prevalence of uncontrolled sepsis and makes it a rare cause of death. Potentially, one of the most dangerous complications is circulatory insufficiency due to damage to the heart´s valvular apparatus. This is consistent with the observations of other researchers (2, 21). Thus, it is essential to chose the optimal moment for surgical intervention to prevent valvular damage and development of congestive heart failure.
Conclusions
1. Cardiac surgery in the course of infective endocarditis is a high-risk procedure regardless of the patient´s age, but in individuals over 65 years the risk is especially high.
2. The mortality rate in elderly patients is higher than in the total operated population.
3. Elderly persons are often diagnosed for reasons of worsening health different from IE, which may delay the onset of proper treatment.
4. The following risk factors of IE are more frequently observed in patients over 65: a history of surgery (including cardiac surgery), invasive diagnostic and therapeutic procedures e.g. gynaecological, urological, dental etc. and long-term hospitalizations.
5. Patients over 65 with previously-implanted heart valve prostheses are in special jeopardy connected with an increased risk of a redo operation.
Piśmiennictwo
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