Prosthetic valve endocarditis with ring abscesses

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Outcomes After Left Ventricular Outflow Tract Reconstruction With a Tube Graft for Annular Erosion

BACKGROUND

Aortic annular erosion is a serious complication of aortic valve endocarditis or previous aortic valve replacement. This study examined the outcomes of a technique for left ventricular outflow tract reconstruction using a polyester tube graft, followed by translocation of the aortic valve and coronary arteries.

METHODS

A total of 23 patients with extensive annular erosion resulting from endocarditis or previous aortic valve replacement with or without pseudoaneurysm formation, or occurring after excision of the native valve, underwent suture of a polyester tube graft in the left ventricular outflow tract below the annulus, replacement of the aortic valve and proximal ascending aorta with a composite graft, and reimplantation of the coronary arteries with the use of interposition polyester grafts. The mean age of the patients was 50 years, and 57% were men.

RESULTS

There were no hospital deaths. The mean duration of follow-up was 6.5 years and extended to 16 years. Actuarial survival at 1, 5, and 10 years was 86.7%, 82.2%, and 62.6%, respectively. Two patients required reoperation for a graft-graft pseudoaneurysm and for degeneration of a porcine bioprosthesis. Echocardiograms obtained at a mean of 75 months postoperatively in 15 of the 23 patients demonstrated normal left ventricular outflow tract dimensions and velocities and a mean effective valve orifice area of 1.07 cm²/m². All coronary artery grafts were patent on angiography a mean of 40 months postoperatively in 13 patients.

CONCLUSIONS

Extended experience with this technique confirms its safety and effectiveness for patients with extensive destruction of the aortic annulus. It represents a suitable alternative to other currently used techniques.

Surgical management of severe damage of the aortic annulus

Aortic annular erosion and abscess are serious complications of prosthetic aortic valve endocarditis and can be treated with aortic valve translocation and left ventricle outflow tract reconstruction. These two surgical techniques seem to have similar early postoperative outcomes, and their use can be considered an option after the failure of conventional surgical methods.

Viridans streptococcal (Streptococcus mitis) biosynthetic aortic prosthetic valve endocarditis (PVE) complicated by complete heart block and paravalvular abscess

Prosthetic valve endocarditis (PVE) may be classified clinically as early (<60 days) or late (>60 days) post-valve replacement PVE. The pathogens of early versus late PVE differ in type and virulence. Early PVE pathogens are virulent, for example, Pseudomonas aeruginosa and Staphylococcus aureus. Late PVE pathogens resemble those of subacute bacterial endocarditis and are due to relatively avirulent and noninvasive organisms, for example, viridans streptococci. Viridans streptococci vary in their invasiveness and abscess potential. Myocardial abscess and complete heart block are rare complications of late PVE due to viridans streptococci. We present an unusual case of Streptococcus mitis late aortic PVE complicated by aortic root abscess, myocardial abscess, and complete heart block.

A case of staphylococcal tricuspid valve endocarditis with para-aortic abscess in a patient with bicuspid aortic valve

Paravalvular abscess is a serious complication of infective endocarditis. The aortic valve and its adjacent ring are more susceptible to abscess formation and paravalvular extension than the mitral valve. A 15-years old patient with bicuspid aortic valve presented with staphylococcal tricuspid valve endocarditis complicated by para-aortic abscess that ruptured into the aortic sinus. We report the clinical, laboratory and echocardiographic features and treatment of this patient and conduct a literature review on this subject.

Circumferential disruption of the ventriculo-aortic junction due to infective endocarditis: surgical repair with custom-made, accurately sized, pericardial tube

Repair of circumferential ventriculo-aortic annular disruption following infective endocarditis is technically challenging. We present an approach for systematic repair and describe a technique for preparation of an accurately sized pericardial tube graft.

Prosthetic valve endocarditis

Prosthetic valve endocarditis (PVE) is associated with a high mortality during the early and midterm follow-up despite diagnostic and therapeutic improvements; its incidence is increasing and reaches 20-30% of all infective endocarditis episodes. In this review, changes in epidemiology, microbiology, diagnosis and therapy that have evolved in the past few years are analyzed. Staphylococci (both Staphylococcus aureus and coagulase-negative Staphylococcus) have emerged as the most common cause of PVE and are associated with a severe prognosis. Moreover, diagnosis may often be difficult because of its complications and extracardiac manifestations; thus, a comprehensive assessment of the clinical, echocardiographic and laboratory data must be performed. Early PVE, comorbidity, severe heart failure and new prosthetic dehiscence are predictors of mortality. Therapy is not indicated by evidence-based recommendations but mostly on identification of the high-risk conditions. A PVE is a common indication for surgery, whereas medical treatment alone may be achieved in a few instances. Systematic prophylaxis should be used to prevent this severe complication of cardiac valve replacement.

Left ventricular outflow tract reconstruction and translocation of the aortic valve for annular erosion: early and midterm outcomes

OBJECTIVE

Aortic annular erosion is a serious complication of aortic valve endocarditis or previous aortic valve replacement without endocarditis, and its surgical management is challenging. We present the early and midterm results of a technique for left ventricular outflow tract and aortic root reconstruction with a polyester tube graft and translocation of the aortic valve and coronary arteries.

METHODS

A polyester tube graft is placed into the left ventricle and sutured to the left ventricular outflow tract below the area of erosion. The graft is then everted and sutured to a composite graft. Interposition polyester grafts from the coronary arteries are attached to the composite graft above the valve. This technique has been used in 12 cases. All but 1 patient had previously undergone aortic root or aortic valve replacement, and 4 had endocarditis of prosthetic (n = 2) or aortic allograft (n = 2) valves.

RESULTS

There were no in-hospital deaths. There was 1 early death from pulmonary embolism at 1 postoperative month and 2 late deaths at 15 and 64 postoperative months, both resulting from heart failure. The remaining 9 patients are alive at 3 to 132 postoperative months. Actuarial 5-year survival is 75%.

CONCLUSIONS

Left ventricular outflow tract reconstruction with translocation of the aortic valve and coronary arteries for annular erosion is a useful technique that safely excludes the area of annular erosion and eliminates left ventricular outflow tract obstruction. The procedure can be safely performed with satisfactory early outcomes and 5-year survival.

Transthoracic echocardiography-guided biopsy of a metastatic endometrial adenocarcinoma in the right atrium: a review of diagnosis and treatment of cardiac masses

We report on a 64-year-old African-American female with a past medical history of an endometrial adenocarcinoma with metastasis to the right atrium. To our knowledge, there have been only four case reports on endometrial carcinoma metastasizing to the right atrium. In our patient, a percutaneous biopsy under fluoroscopic and transthoracic echocardiographic guidance was performed. Histopathologic evaluation of the specimens revealed an adenocarcinoma, consistent with the patient's history of endometrial carcinoma. This report provides a brief review of diagnosis and treatment of cardiac masses.

Risk factor analysis of hospital mortality in patients with endocarditis with ring abscess

BACKGROUND

Endocarditis associated with ring abscess is a pathology with high morbidity and mortality.

AIM OF THE STUDY

The purpose of this study was to analyze hospital mortality risk factors in patients with ring abscess due to endocarditis.

METHODS

From January 1982 to December 2000, 104 patients underwent surgical intervention at the Heart Institute of the University of São Paulo Medical School for valve endocarditis with ring abscess. The age ranged from 6 years to 73 years, with an average of 40.3 years and 72.1% were male. According to NYHA functional class (FC), 12 (11.5%) were in FC II, 62 (59.6%) in FC III, and 30 (28.9%) in FC IV. Seventy-seven (74.0%) patients had endocarditis on a bioprosthesis, 58 (55.8%) in the aortic position and 19 (18.3%) in the mitral position. Twenty-nine (26.9%) patients had atrioventricular blockage prior to the operation. Univariate analysis was performed comparing variables and hospital mortality with a level of significance of 5%. Multivariate analysis was performed by logistic regression.

RESULTS

The hospital mortality was 19.2% (20 patients). Univariate analysis showed that atrioventricular blockage, age, and prosthetic valve endocarditis significantly influenced hospital mortality. Multivariate analysis identified atrioventricular blockage as an independent predictor of hospital mortality.

CONCLUSIONS

Preoperative atrioventricular blockage is an independent risk factor for hospital mortality in the surgical treatment of endocarditis with ring abscess.

Predictors of Mortality in Paravalvular Abscess

BACKGROUND

Paravalvular abscess formation is an ominous complication of infective endocarditis; however, prognostic variables in paravalvular abscess are poorly defined.

METHODS

We examined our experience in patients with paravalvular abscess between 1987 and 2004. Clinical, echocardiographic, microbiologic, and surgical data were examined.

RESULTS

There were 45 patients (17 females), age 57 +/- 17 years. Twenty-four patients had prosthetic valve endocarditis. Methicillin-sensitive Staphylococcus aureus and coagulase-negative S. aureus were the most common organisms accounting for 25 (56%) cases. Thirty-eight patients (84%) underwent surgery during initial admission. Surgical mortality was 7%, in-hospital mortality was 31%, and 1-year mortality was 38%. Between patients who died and patients who survived, there were no differences in age (61 +/- 20 years vs 55 +/- 15 years, P = .3), type of microorganism, presence of prosthetic heart valves (47% vs 57%), presence of moderate to severe or severe regurgitation of involved valve (47% vs 57%, P = .37), presence of associated valvular vegetation (93% vs 93%), area of abscess (5.6 +/- 2.9 cm2 vs 4.4 +/- 3.2 cm2, P = .39), left ventricular systolic function (56% +/- 13% vs 56% +/- 10%, P = .9), white cell count (13 +/- 4 vs 13 +/- 7, P = .9), or polymorphonuclear leukocytosis (86% +/- 6% vs 81% +/- 9%, P = .1). Patients who died were sicker on admission compared with those who survived (33% had stroke or altered mental status vs 7%, P = .03) and had worse renal function compared with those who survived (creatinine 4 +/- 4 mg/dL vs 1.6 +/- 1.9 mg/dL, P = .009).

CONCLUSION

Neurologic impairment and renal impairment are significant determinants of 1-year survival in patients who present with paravalvular abscess.

Prosthetic valve endocarditis

Prosthetic valve endocarditis is a catastrophic complication of cardiac valve replacement, associated with high mortality rates. Medical treatment is effective in a few instances of endocarditis involving the leaflets alone in bioprostheses. However, accurate diagnosis, better myocardial protection, and improved surgical strategies have led to better survival in patients undergoing surgery after failed conservative therapy. This comprehensive review addresses various issues involved in the management of this complication.

Bacteriological Outcome after Valve Surgery for Active Infective Endocarditis: Implications for Duration of Treatment after Surgery

BACKGROUND

There has been no systematic evaluation of outcome after surgery for infective endocarditis with respect to duration of antibiotic treatment.

METHODS

We performed a retrospective chart review of episodes of valve surgery for active infective endocarditis at Green Lane Hospital (Auckland, New Zealand) for 1963-1999. We recorded the duration of antibiotic treatment before and after valve surgery; the extent of infection at operation; Gram stain, culture, and histopathological testing results for valve samples; and the bacteriological outcome after surgery. The primary outcome measure was relapse, defined as endocarditis due to the same species within 1 year after surgery.

RESULTS

For the 358 patients in our study, the median duration of follow-up was 4.8 years. Thirty-two patients (9%) had 36 subsequent episodes of endocarditis. Relapse occurred after 3 (0.8%) of the operations (95% CI, 0.2%-2.0%). Relapse of infection was unrelated to the duration of antibiotic treatment before or after surgery, positive valve culture results, positive Gram stain results, or perivalvular infection. Since 1994, we have reduced the duration of antibiotic treatment by approximately 7 days for those with positive valve culture results and by approximately 14 days for those with negative valve culture results, without any increase in the number of relapses.

CONCLUSIONS

Relapse is an uncommon event following surgery for endocarditis. Commonly suggested indications for prolonging postoperative treatment are not associated with higher relapse rates, and their relevance is debatable. We conclude that it is unnecessary to continue treatment for patients with negative valve culture results for an arbitrary 4-6-week period after surgery. Two weeks of treatment appears to be sufficient, and, for those operated on near the end of the standard period of treatment, simply completing the planned course should suffice.

Aortic Valve Translocation for Severe Prosthetic Valve Endocarditis: Early Results and Long-Term Follow-Up

BACKGROUND

Surgical management of ventriculo-aortic disconnection and aortic root abscesses after prosthetic aortic valve endocarditis carries high mortality and morbidity. Initial experience with translocation of the aortic valve and distal coronary artery bypass grafting was disappointing in terms of short-term and long-term success in the few published reports. We describe a technique of translocation of the aortic valve into the ascending aorta with direct antegrade myocardial revascularization.

METHODS

Between 1980 and 1992, we included 21 patients and evaluated their long-term outcome. The surgical technique included extracting the aortic valve prosthesis, resecting all infected tissue, restoring the left ventricular outflow tract, and translocating the aortic valve into the ascending aorta, associated with myocardial revascularization of the left main trunk and the proximal right coronary artery.

RESULTS

All patients required emergency surgery: 15 patients were in severe congestive heart failure, 3 patients were in cardiogenic shock, and 3 patients had multiple neurologic and peripheral signs of distal embolization. Fifteen patients had active prosthetic valve endocarditis. Intraoperative findings dictated the translocation. The overall hospital mortality was 14%. None of the 18 hospital survivors had prosthetic aortic valve endocarditis recurrence. All patients were observed from 12 to 22 years, are alive, and have resumed normal activities.

CONCLUSIONS

In severe forms of prosthetic valve endocarditis, this technique provides a safe and reliable alternative to homograft replacement. The long-term results are satisfactory.

Prosthetic valve endocarditis with extensive aortic root abscess

Prosthetic valve endocarditis with an extensive aortic root abscess usually has high mortality and morbidity. A 71-year-old male with an extended aortic root abscess following aortic valve replacement survived after full aortic root reconstruction with glutaraldehyde bovine pericardium, mitral valve replacement and full root replacement using stentless bioprosthesis. The patient is well without recurrence of infection, 18 months postoperatively. This procedure might be an alternative treatment for prosthetic valve endocarditis with an extended aortic root abscess.

Infections of intracardiac devices

Intracardiac devices are increasingly used to correct hemodynamically dysfunctional valves and electrophysiologic abnormalities. These devices become infected at relatively low rates. Nevertheless, when these low rates are applied to widely used devices, significant numbers of infections result. Additionally, these infections have been associated with high degrees of morbidity and high mortality rates. This article reviews the epidemiology, microbiology, clinical presentation, and medical as well as surgical therapy of intracardiac device infections.

Current best practices and guidelines. Indications for surgical intervention in infective endocarditis

Optimal diagnosis and management of patients with infective endocarditis requires sound clinical judgment based on extensive experience. This is especially important in regard to the indications and timing for surgery. To achieve the best possible outcomes, surgical intervention during treatment is required in 25% to 30% of patients with infective endocarditis. Heart failure and progressive left-sided valvular dysfunction are the most common indications for operation. Valve repair should be considered as an alternative to valve replacement whenever feasible, especially in younger patients. Successful management of perivalvular abscesses and prosthetic valve infections requires radical removal of infected tissue followed by reconstructive procedures performed by experienced surgeons. Emergency or urgent surgery should seldom be delayed.

Aortic root replacement with cryopreserved allograft for prosthetic valve endocarditis

BACKGROUND Our strategy has been to treat aortic prosthetic valve endocarditis (PVE) with radical debridement of infected tissue and aortic root replacement with a cryopreserved aortic allograft. This study examines the effectiveness of this strategy on hospital mortality and morbidity, recurrent endocarditis, and survival.

METHODS

From 1988 through 2000, 103 patients with aortic PVE underwent root replacement with a cryopreserved aortic allograft. Abscesses were present in 78%, and aortoventricular discontinuity was present in 40%. Thirty-two patients had at least one previous operation for endocarditis. In 23 patients with a history of native valve endocarditis, the allograft was implanted after one episode (17 patients), two episodes (5 patients), or three episodes of PVE (1 patient). In the 80 patients without a history of native valve endocarditis, the allograft was placed after one previous aortic valve replacement (57 patients), two (19), or three (4) previous aortic valve replacements. Among the 92 patients with positive cultures, 52 had staphylococcal organisms, 20 had streptococcal, 6 had fungal, 4 had gram-negative, and 6 had enterococcal organisms. Mean follow-up was 4.3 +/- 2.9 years.

RESULTS

Hospital mortality was 3.9%. Permanent pacemakers were required in 31 patients. Survival at 1 year, 2 years, 5 years, and 10 years was 90%, 86%, 73%, and 56%, respectively, with a risk of 5.3% per year after 6 months. Four patients underwent reoperation for recurrent PVE of the allograft (95% freedom from recurrent PVE at > or = 2 years). Risk of recurrent PVE peaked at 9 months and then declined to a low level by 18 months.

CONCLUSIONS

A strategy of radical debridement and aortic root replacement with a cryopreserved aortic allograft for aortic PVE is safe, effective, and recommended.

Current best practices and guidelines indications for surgical intervention in infective endocarditis

Optimal diagnosis and management of patients with infective endocarditis requires sound clinical judgment based on extensive experience. This is especially important in regard to the indications and timing for surgery. To achieve the best possible outcomes, surgical intervention during treatment is required in 25% to 30% of patients with infective endocarditis. Heart failure and progressive left-sided valvular dysfunction are the most common indications for operation. Valve repair should be considered as an alternative to valve replacement whenever feasible, especially in younger patients. Successful management of perivalvular abscesses and prosthetic valve infections requires radical removal of infected tissue followed by reconstructive procedures performed by experienced surgeons. Emergency or urgent surgery should seldom be delayed.

Infections of intracardiac devices

Intracardiac devices are increasingly used to correct hemodynamically dysfunctional valves and electrophysiologic abnormalities. These devices become infected at relatively low rates. Nevertheless, when these low rates are applied to widely used devices, significant numbers of infections result. Additionally, these infections have been associated with high degrees of morbidity and high mortality rates. This article reviews the epidemiology, microbiology, clinical presentation, and medical as well as surgical therapy of intracardiac device infections.

[Surgical reconstruction of intervalvular fibrous body in active infective endocarditis]

INTRODUCTION AND OBJECTIVES

Surgery for infective endocarditis with paravalvular abscesses and fibrous body destruction has the highest mortality and morbidity rates in this disease with high surgical risk. We report a new approach of radical resection of the abscess and affected tissues and reconstruction of the heart with pericardium as an alternative to conventional surgery.

METHODS

In the last two years six patients with infective endocarditis, paravalvular abscesses and fibrous body destruction underwent surgery (five prostheses with infective endocarditis). The main indication for surgery was persistent sepsis despite adequate antibiotic treatment in five patients and congestive heart failure in one. After wide resection of the abscesses and fibrous body the heart was reconstructed with glutaraldehyde-fixed bovine pericardium.

RESULTS

There was no hospital mortality. The median bypass and clamp times were 198 and 174 minutes, respectively. One patient presented complete AV block and a permanent transvenous pacemaker was implanted. Doppler echocardiographic studies performed in all the patients prior to discharge indicated that no patient had patch dehiscence or paravalvular leaks. Patients were followed a mean of 15 months with no deaths or other complications being reported.

CONCLUSIONS

Resection of the abscesses and fibrous body, and reconstruction of the heart with glutaraldehyde-fixed bovine pericardial patch is a radical, feasible technique with all infected tissues being resected to thereby prevent reinfection or paravalvular leaks.

Immediate and long-term results of valve replacement for native and prosthetic valve endocarditis

BACKGROUND

The objective of the present study was to compare current results of prosthetic valve replacement following acute infective native valve endocarditis (NVE) with that of prosthetic valve endocarditis (PVE). Prosthetic valve replacement is often necessary for acute infective endocarditis. Although valve repair and homografts have been associated with excellent outcome, homograft availability and the importance of valvular destruction often dictate prosthetic valve replacement in patients with acute bacterial endocarditis.

METHODS

A retrospective analysis of the experience with prosthetic valve replacement following acute NVE and PVE between 1988 and 1998 was performed at the Montreal Heart Institute.

RESULTS

Seventy-seven patients (57 men and 20 women, mean age 48 +/- 16 years) with acute infective endocarditis underwent valve replacement. Fifty patients had NVE and 27 had PVE. Four patients (8%) with NVE died within 30 days of operation and there were no hospital deaths in patients with PVE. Survival at 1, 5, and 7 years averaged 80% +/- 6%, 76% +/- 6%, and 76% +/- 6% for NVE and 70% +/- 9%, 59% +/- 10%, and 55% +/- 10% for PVE, respectively (p = 0.15). Reoperation-free survival at 1, 5, and 7 years averaged 80% +/- 6%, 76% +/- 6%, and 76% +/- 6% for NVE and 45% +/- 10%, 40% +/- 10%, and 36% +/- 9% for PVE (p = 0.003). Five-year survival for NVE averaged 75% +/- 9% following aortic valve replacement and 79% +/- 9% following mitral valve replacement. Five-year survival for PVE averaged 66% +/- 12% following aortic valve replacement and 43% +/- 19% following mitral valve replacement (p = 0.75). Nine patients underwent reoperation during follow-up: indications were prosthesis infection in 4 patients (3 mitral, 1 aortic), dehiscence of mitral prosthesis in 3, and dehiscence of aortic prosthesis in 2.

CONCLUSIONS

Prosthetic valve replacement for NVE resulted in good long-term patient survival with a minimal risk of reoperation compared with patients who underwent valve replacement for PVE. In patients with PVE, those who needed reoperation had recurrent endocarditis or noninfectious periprosthetic dehiscence.

[Practice guidelines of the Spanish Society of Cardiology on endocarditis]

Infectious endocarditis is a disease which mainly involves the cardiac valves. It has a bad prognosis and is caused by a great variety of microorganisms. Prophylaxis is important although the effectiveness and the best way to achieve it remain unclear. Recommendations are herein presented. The diagnosis is based on clinical, bacteriological, and echocardiographic findings mainly based on Duke's criteria. Transthoracic and transesophageal echography are not only of diagnostic value but are also a tool to determine the therapy to follow. Antibiotic therapy should be selected according to the organisms isolated and their in vitro susceptibility. Guidelines for empirical antibiotic therapy in cases of negative cultures are also included. Lastly, indications and time for surgery are discussed.

[A case of aortic prosthetic valve endocarditis with aortic root aneurysm]

A 72-year-old male who underwent patch closure of atrial septal defect and aortic valve replacement (AVR) 10 years ago was diagnosed as aortic prosthetic valve endocarditis for recurrent fever, coexisting paravalvular leakage and aortic root aneurysm by transthoracic and transesophageal echocardiography. Operative findings showed mechanical prosthesis was dehiscenced in part and limited subannular aneurysm that was healed macroscopically. The hole of the aneurysm was closed by direct suture. Re-AVR, mitral valve replacement and tricuspid annuloplasty for complicating mitral valve stenosis and regurgitation and tricuspid valve regurgitation was performed. The patient is now doing well for one year after the reoperation.

Surgical treatment of endocarditis

Since early investigators first suggested that the treatment of endocarditis should include valve replacement for infections not readily controlled with medical therapy alone, the role of surgery has become expanded, yet refined, to improve the outcome of patients with this potentially fatal disease. Innovative surgical techniques have also been developed in an effort to improve the results of surgical treatment for complex sequelae of invasive infections. This article examines the current indications for surgical intervention, compares the various surgical options, and assesses the expected short-and long-term outcome after valve replacement for patients with native valve or prosthetic valve endocarditis.

Allograft aortic root replacement in prosthetic aortic valve endocarditis: a review of 32 patients

BACKGROUND

This study was conducted to evaluate allograft aortic root replacement in the setting of complicated prosthetic valve endocarditis with extensive annular destruction.

METHODS

From January 1990 through March 1996, 32 patients diagnosed with complicated prosthetic valve endocarditis underwent allograft root replacement. Mean age was 58.3 +/- 13.2 years; 23 patients were men. Mean preoperative New York Heart Association functional class was 3.4. Staphylococcus epidermidis (50%) and Enterococcus faecalis (19%) were the predominant causative microorganisms. Annular abscesses were found in 26 patients (81%), aortic-mitral discontinuity in 14 patients (43%), and left ventricular-aortic discontinuity in 11 patients (34%). A cryopreserved allograft was used in 31 patients (97%) and a fresh antibiotic-treated allograft was used in 1 patient (3%). Mean aortic cross-clamp time was 150 +/- 29 minutes. Mean duration of the postoperative antibiotic treatment was 38.5 +/- 11.8 days.

RESULTS

There were three operative deaths (9.4%); causes of death were multiorgan failure in 2 patients (6.2%) and low cardiac output in 1 patient (3.2%). Six patients (18%) had complete heart block (4 patients already before the operation), 3 patients (9.4%) had temporary respiratory insufficiency, and 1 patient (3.2%) needed temporary hemodialysis. Mean follow-up was 37.4 +/- 22.4 months. Two late deaths occurred: 1 patient had recurrent endocarditis, leading to a false aneurysm, and died at reoperation; another patient died of lung cancer. Actuarial 5-year survival was 87.3% (70% confidence interval, 76.8% to 97.8%); actuarial 5-year freedom from recurrent endocarditis was 96.5% (70% confidence interval, 90.0% to 100%).

CONCLUSIONS

Allograft aortic root replacement is a valuable technique in the complex setting of prosthetic valve endocarditis with involvement of the periannular region. Mortality and morbidity are low.

Long-term results of operation for paravalvular abscess

BACKGROUND

Operation for infective endocarditis with paravalvular abscess is reportedly associated with high mortality and morbidity rates. In an attempt to improve surgical outcome, an approach of radical resection of the abscess and inflamed tissues and reconstruction of the heart with either fresh or glutaraldehyde-fixed bovine pericardium was adopted by two surgeons at our institution.

METHODS

From 1979 to 1995, 70 consecutive patients with active infective endocarditis and paravalvular abscess underwent operation. Their mean age was 49 years (range, 16 to 75 years), and 50 patients (71%) were men. Thirty-four patients had native and 36 had prosthetic valve endocarditis (8 had had composite replacement of the aortic valve and ascending aorta). Most patients (78%) were in New York Heart Association functional class IV. The principal indication for operation was cardiogenic or septic shock in 11 patients, or one or more of the following: persistent sepsis despite adequate antibiotic therapy in 36, congestive heart failure in 31, and recurrent emboli in 16. Staphylococci were responsible for the infection in 37 patients (53%). The abscess was in the mitral annulus in 11 patients, in the aortic root in 44, and in the aortic root and at least one other annulus in 15. After wide resection of the abscess, we reconstructed the heart and annuli with autologous or bovine pericardium. Mechanical heart valves were implanted in 36 patients, bioprostheses in 30, and aortic homografts in 2; valve repair was possible in 2. Sixteen patients required composite replacement of the ascending aorta and aortic valve.

RESULTS

There were 9 operative deaths (13%). Infections caused by staphylococci and infections in multiple annuli were associated with increased operative mortality rates. Only 1 patient had persistent infection and required reoperation. The mean follow-up was 56 +/- 40 months. There were 12 late deaths, mostly cardiac. The actuarial survival including operative deaths was 64% +/- 8% at 8 years. In 8 patients, recurrent infective endocarditis developed 10 to 102 months after operation. The freedom from recurrent endocarditis was 76% +/- 10% at 8 years.

CONCLUSIONS

This experience indicates that radical resection of the abscess and reconstruction of the heart with pericardium yield an excellent chance of eradicating the infection in patients with infective endocarditis and paravalvular abscess. The type of valve implanted may not be as important as radical resection of the abscess. These patients appear to have a greater than average risk of recurrent endocarditis.

Surgical treatment of prosthetic valve endocarditis

From 1975 through 1992, we reoperated on 146 patients for the treatment of prosthetic valve endocarditis. Prosthetic valve endocarditis was considered to be early (< 1 year after operation) in 46 cases and active in 103 cases. The extent of the infection was prosthesis only in 66 patients, anulus in 46, and cardiac invasion in 34. Surgical techniques evolved in the direction of increasingly radical débridement of infected tissue and reconstruction with biologic materials. All patients were treated with prolonged postoperative antibiotic therapy. There were 19 (13%) in-hospital deaths. Univariate analyses demonstrated trends toward increasing risk for patients with active endocarditis and extension of infection beyond the prosthesis; however, the only variables with a significant (p < 0.05) association with increased in-hospital mortality confirmed with multivariate testing were impaired left ventricular function, preoperative heart block, coronary artery disease, and culture of organisms from the surgical specimen. During the study period, mortality decreased from 20% (1975 to 1984) to 10% (1984 to 1992). For hospital survivors the mean length of stay was 25 days. Follow-up (mean interval 62 months) documented a late survival of 82% at 5 postoperative years and 60% at 10 years. Older age was the only factor associated (p = 0.006) with late death. Nineteen patients needed at least one further operation; reoperation-free survival was 75% at 5 and 50% at 10 postoperative years. Fever in the immediate preoperative period was the only factor associated with decreased late reoperation-free survival (p = 0.032). Prosthetic valve endocarditis remains a serious complication of valve replacement, but the in-hospital mortality of reoperations for prosthetic valve endocarditis has declined. With extensive débridement of infected tissue and postoperative antibiotic therapy, the extent and activity of prosthetic valve endocarditis does not appear to have a major impact on late outcome, and the majority of patients with this complication survive for 10 years after the operation.

Determinants of early mortality and late survival in mitral valve endocarditis

BACKGROUND

Infective mitral valve endocarditis continues to be a significant surgical challenge. The objective of this study was to examine our experience with mitral valve endocarditis surgery and identify determinants of early mortality and late survival.

METHODS AND RESULTS

Over a 24-year period, mitral valve surgery was performed in 96 patients for infective mitral valve endocarditis. Patient age ranged from 20 to 78 years (median age, 52 years). There were 44 women (46%), and 48 of the 96 patients (50%) were in New York Heart Association functional class IV before surgery. Native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE) were present in 72 patients (75%) and 24 patients (25%), respectively. Surgery during the active phase of endocarditis (AE) was required in 60 patients (62%) and during the healed phase (HE) in 36 (38%). The main indications for surgery in the AE group were congestive heart failure (60%), active sepsis (67%), peripheral emboli (47%), and acute renal failure (20%), and for the HE group the main indication was progressive congestive heart failure (69%). The overall operative mortality was 5.2%. Multivariate logistic regression analysis identified PVE (odds ratio [OR] 22.5; +/- 95% confidence interval, CI, 1.9 to 268; P = .014) and an associated procedure (OR 13.3; +/- 95% CI, 1.5 to 120; P = .021) to be independent predictors for early mortality. Follow-up was 97% complete, with a median of 3.5 years. Overall 5- and 10-year survivals were 83 +/- 4% and 63 +/- 8%, respectively. Multivariate analysis for late mortality identified PVE to be a significant predictor of late mortality (hazards ratio = 3.1, +/- 95% CI, 1.4 to 6.8, P = .006). There were no significant differences in long-term morbidity results among the various subsets of mitral valve endocarditis.

CONCLUSIONS

Mitral valve surgery for infective endocarditis is a significant high-risk procedure for PVE and when combined with associated procedures. The activity of endocarditis does not appear to have any influence on early mortality or long-term survival.

Immediate and long-term results following repair of aortic left ventricular discontinuity: a 25-year experience

From 1967 to 1993, 21 patients underwent surgical repair of aortic left ventricular discontinuity as a result of acute bacterial endocarditis. Repair of the defect between the aorta and left ventricle was usually with interposition of a patch (prosthetic patch or autologous pericardium), using a continuous monofilament suture. Interrupted pledgetted stitches were used when the ventricular tissue appeared friable. A valve prosthesis was then sewn to the patch and remaining annulus. Three patients died in the immediate perioperative period. Long follow-up ranging from 5 to 142 months (mean 36 months) is available on 17 of 18 survivors. There were six deaths in this group from 11 to 142 months (mean 67 months) from initial surgery. Of 11 long-term survivors (5 to 61 months (mean 21 months) after operation), nine have had event-free courses. Two cases of recurrent subacute bacterial endocarditis occurred 3 and 52 months after surgery in patients who were intravenous drug abusers, both of whom were managed medically. It is concluded that while aortic left ventricular discontinuity remains a potentially lethal complication of acute bacterial endocarditis, débridement of infected necrotic tissue, patch repair of the defect, and prosthetic valve replacement offer satisfactory immediate and late results.

Endocarditis-associated paravalvular abscesses. Do clinical parameters predict the presence of abscess?

STUDY OBJECTIVE

To determine whether standard clinical and transthoracic echocardiographic criteria considered to be suggestive of the presence of endocarditis-associated paravalvular abscess are predictive of which patients would benefit from reliable but invasive transesophageal echocardiographic investigations for abscess.

DESIGN

Retrospective chart review.

SETTING

A 630-bed university hospital.

PATIENTS

Forty-eight patients with 51 episodes of definite endocarditis and 24 paravalvular abscesses.

MEASUREMENTS AND RESULTS

A comparison of abscess and nonabscess populations revealed that clinical parameters (patient demographics, valvular involvement, presence of a prosthesis, infection with a virulent organism, pericarditis, persistent fever, persistent bacteremia, congestive heart failure, history of intravenous drug use, embolization) and transthoracic echocardiographic parameters were insensitive predictors of the presence of abscess. The only statistically significant correlate was the presence of previously undetected atrioventricular or bundle branch block. Paravalvular abscesses were common in our population and were associated with increased mortality. Improved survival correlated with the absence of mitral valve involvement and the absence of moderate-to-severe congestive heart failure.

CONCLUSIONS

Given the accuracy and safety of transesophageal echocardiography and the unreliability of clinical and transthoracic echocardiographic criteria, we recommend that transesophageal echocardiography be considered in all endocarditis patients with previously unrecognized conduction disturbances, aortic or prosthetic valve involvement, or both, or indications for valve replacement, or all of the foregoing.

Mitral valve replacement with a collar-reinforced prosthetic valve for disrupted mitral annulus

The mitral valve was replaced with a collar-reinforced prosthetic valve in 6 patients with a disrupted mitral annulus, in 3 because of infective endocarditis, including 2 patients with prosthetic valve endocarditis, in 2 because of a severely calcified mitral annulus, and in 1 who had previously undergone mitral valve replacement twice. Four patients had undergone prior mitral operations; these consisted of mitral valve replacement in 3 patients and mitral valve repair in 1. In all patients, the prosthesis was secured by double-layered sutures, with the first row of buttressed sutures passing through the leaflet or sutured to the left ventricular muscle and through the sewing cuff of the prosthetic valve. The second row of running sutures was then placed through an extended annular equine pericardial cuff of the prosthetic valve and the supraannular left atrial wall. In 2 patients, all chordae tendineae were preserved to maintain annulopapillary muscle continuity. All patients survived and have remained well for a mean of 22.3 months. There has been no prosthetic valve dehiscence, except for minimal paraprosthetic leakage in 1 patient. These results demonstrate that mitral valve replacement in patients with a disrupted mitral annulus can be successfully accomplished with a collar-reinforced prosthetic valve.

Bilateral vs single internal thoracic artery grafting for left main coronary artery occlusion

This study was conducted to compare the coronary flow distributed by single and bilateral internal thoracic artery (ITA) grafts in the setting of the left main coronary occlusion. Ten dogs underwent coronary artery bypass grafting through a left thoracotomy, off pump, using a brief local occlusion to perform the anastomosis. Dogs were randomly assigned to receive either a single left ITA (LITA) graft to the circumflex coronary artery (CFX), or bilateral ITA grafts, with additional placement of the right ITA (RITA) to the left anterior descending artery (LAD). After the grafts were placed, the left main coronary artery was ligated. Electromagnetic flows were obtained in the LAD and the CFX proximally and distally to ITA grafts in both groups before grafting and after grafting. ITA flow in situ was also measured before rotation from the chest wall. Total left ventricular flow requirements were satisfied equally well by either a single LITA graft (116.7 +/- 11.6 mL/min) or bilateral ITA grafts (total, 116.8 +/- 9.6 mL/min divided as LITA, 55.9 +/- 7.4 mL/min; RITA, 60.9 +/- 12.0 mL/min). When two grafts were replaced, competitive flow in the proximal regions of both native vessels was noted, although basal flow requirements were maintained. When an individual graft was occluded in the bilaterally grafted system, the remaining graft immediately recruited the additional flow, demonstrating that either right or left ITA can support flow demands five to six times higher than in situ chest wall flow (RITA, 21.9 +/- 3.1 mL/min; LITA, 22.3 +/- 4.9 mL/min). These data suggest that in this canine model, a single ITA graft can support the entire flow requirements of the left ventricle. Assuming no intervening stenosis is present in native coronary systems, bilateral ITA grafting may provide a margin of safety, but under resting conditions, provides no perfusion advantages over a single ITA graft.

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.