Comparison of infective endocarditis in drug addicts and nondrug users

Endocarditis and the impact of intravenous drug use: a cohort study

OBJECTIVES

This cohort study is a comparison of infective endocarditis in intravenous drug users (IDUs) and non-IDUs within a single tertiary centre. We aim to quantify and describe the factors that influence prognosis and microbiological characteristics.

METHOD

All consecutive admissions to a tertiary referral hospital in the north of England with a diagnosis of endocarditis from April 2013 to January 2020 were identified. Outcomes were all-cause mortality at 30 days, 12 months and 3 years, length of stay and progression to surgery.

RESULTS

A total of 303 cases were identified via clinical coding of which 287 cases of endocarditis were confirmed. First episode endocarditis was then confirmed in 263 episodes, 44 in IDUs and 219 in non-IDUs. Methicillin sensitive Staphylococcus aureus (MSSA) was the most common organism seen overall, significantly more so in IDU than non-IDU cases (29/44 [65.9%] vs. 51/219 [23.3%], p < .001). Overall progression to valve surgery was similar between the two groups (92/219 [42.0%] vs. 19/44[43.2%], p = .886). In IDUs 30-d survival was 93% (80-98) and 3-year survival 47% (30-63%). In non-IDU 30-d survival was 88% (83-92%) and 60% (53-67%) at 3 years. Of the 19 IDUs who underwent valve surgery 7 (37%) survived to study completion without reinfection and 8 (42%) died following recurrent endocarditis.

CONCLUSIONS

We demonstrate that prognosis in IDUs is worse than previously described, particularly in those undergoing valve surgery. This is despite comparable receipt of inpatient treatment to non-IDUs as demonstrated by equal length of stay and rates of surgery. Clinicians should consider the role of addictions services on discharge to break the cycle of reinfection.

Infective endocarditis in the injection drug user

Although infective endocarditis is certainly not the most common infection seen in injecting drug users, it is the infection that clinicians most commonly think of when they consider infectious complications of injected drug use. The microbiology of infective endocarditis in injection drug users has remained relatively stable over the last several decades. Tricuspid valve endocarditis has been associated most frequently with injection drug use, but recent reports have suggested that involvement of left-sided valves is seen more often now than in the past. The use of transesophageal echocardiography has greatly advanced the ability to diagnose infective endocarditis and the cardiac complications of valvular infection.

Wangiella dermatitidis endocarditis in an intravenous drug user

Wangiella dermatitidis is an infrequently encountered dematiacious fungus that usually causes localized infections of the skin and subcutaneous tissues. This report presents the first well-documented case of natural valve infection caused by this organism as it occurred in intravenous drug abuser. His course has been complicated by relapsing infection of two aortic prostheses and dissemination to the vertebral spine. Treatment with a combination of amphotericin B, rifampin, and ketoconazole has arrested the progression of his infection. The microbiologic features and existing clinical information regarding this fungus are reviewed and in vitro susceptibility data for the present isolate are presented.

Acute endocarditis in drug addicts: surgical treatment for multiple valve infection

In 72 drug abusers surgically treated for acute infective endocarditis, 14 patients (19%) required surgical procedures on two valves. The predominant infecting organisms were Staphylococcus aureus and Pseudomonas aeruginosa (29%). In contrast to single valve infection, congestive heart failure was the most common operative indication (86%, p less than 0.05) and was uniformly present when both left-sided valves were involved. Surgery was performed 20 +/- 13 days after initiation of antibiotic therapy, yet 7 of the 14 patients had perivalvular abscess formation. In nine patients with solely left-sided infection, aortic and mitral valve replacements were performed. In five patients with bilateral infection, partial or complete tricuspid valvectomy was performed in conjunction with one aortic and four mitral valve replacements. Tricuspid valve competence was reestablished by valve insertion or anuloplasty in two patients, and these patients experienced less perioperative heart failure than did those with tricuspid excision alone. There was no early (less than 30 day) mortality. However, long-term follow-up revealed a reoperative incidence of 21% and a 36% late mortality rate due to prosthetic valve infection with or without dehiscence at 3 to 18 months (mean 7.2 +/- 6) after the initial operation. These late infectious complications were not related to infecting organism or prosthetic material in the tricuspid anulus, but did occur in four (57%) of seven patients with intracardiac abscess. The data indicate that multiple valve infection does not preclude successful early surgical therapy, maintaining tricuspid competence may be hemodynamically preferable, and reinfection in this addict population increases late mortality.

Clinical and echocardiographic correlations in right heart endocarditis

The echocardiographic findings were correlated with the clinical findings and outcome in 23 patients with tricuspid valve or pulmonary valve endocarditis. There were 15 males and 8 females with a mean age of 33.1 +/- 8.4 years. Eighteen patients had tricuspid valve endocarditis, 1 patient had pulmonary valve endocarditis, 3 patients had concomitant mitral valve and tricuspid valve endocarditis, and 1 patient had tricuspid valve and pulmonary valve endocarditis. Twenty of the 23 (87%) patients had a history of intravenous drug abuse. The most common organisms were Staphylococcus aureus (10 of 23 patients or 43%), Streptococcus viridans (5 patients) and Pseudomonas aeruginosa (4 patients). Pulmonary manifestations with septic pulmonary emboli were present in 18/23 (80%) patients, and a regurgitant murmur in 16/23 (73%) patients. Vegetations on the tricuspid valve or pulmonary valve were detected in all patients who had 2D echo, but they were missed by M-mode echo in 2 patients. Nine of the 23 patients (40%) improved on medical therapy, 5 (21%) expired, and 7 (30%) required surgery (tricuspid valve or pulmonary valve replacement in 3, and tricuspid valve excision without replacement in 4).

CONCLUSIONS

(1) 11 of 13 patients with persistent infection, multivalvular involvement, fungal or Pseudomonas infection and increasing size of vegetations by echo died or underwent surgery compared to only 1 of 8 patients without these features (P less than 0.01). (2) Staphylococcus aureus infection (10 patients) and flail tricuspid valve or pulmonary valve by echo (6 patients) were not predictive of outcome.

Intravenous drug addiction--staphylococcal septicemia--pulmonary embolism: a triad pathognomonic for tricuspid valve endocarditis?

28 patients (29 episodes) presenting the triad of intravenous narcotic drug addiction, Staphylococcus aureus septicemia and septic pulmonary embolism were examined for the presence of tricuspid valve endocarditis. In a prospective study, 12/13 patients examined by echocardiography had vegetations on the tricuspid valve, in 6 detected by M-mode, in 5 by 2-D technique, and in one by both methods. In 4 patients with tricuspid endocarditis, no significant murmurs were heard. Similarly, in a retrospective study, 5/16 patients not subjected to echocardiography had no murmurs consistent with tricuspid valve endocarditis. One of these patients died. In 2/16 patients the diagnosis was verified at autopsy and in 1 at heart surgery. In both groups, altogether 11 patients never developed murmurs, in 7 of them despite demonstrable vegetations. Therefore, we consider the triad to be pathognomonic for tricuspid valve endocarditis, provided that no peripheral source of emboli is present. Consequently, patients fulfilling these criteria should be treated as suffering from endocarditis. Echocardiographic examination does not seem necessary in patients with a typical clinical picture but may be helpful when chest X-rays are inconclusive or complications are suspected.

Valve replacement for left-sided endocarditis in drug addicts

Eighteen drug addicts with left-sided valvular endocarditis requiring operation are reviewed. Gram-positive bacteria were the most common organisms cultured (61%), with Staphylococcus aureus present in 7 of 11 patients. Gram-negative bacteria, exclusively Pseudomonas aeruginosa, were cultured in the remaining 39%. Indications for operation included sepsis (61%), heart failure (78%), and systemic emboli (22%). Abscesses formed in 6 of 11 patients with gram-positive endocarditis, while only one abscess was present with gram-negative endocarditis. Normal valves were infected in 17 of 18 patients (94%). Early surgical mortality (less than 30 days) was 11%. There were major complications in 79% of these patients, including persistent sepsis (50%), valvular dehiscence, prosthetic endocarditis or perivalvular leakage (37%), and mycotic aneurysms (22%). These complications were directly related to a late mortality of 44%, yielding an overall mortality of 50% in the first nine months after operation. Contrary to previous reports of acceptable surgical survival for valvular endocarditis, these data suggest that endocarditis involving the aortic or mitral valve in a drug addict is a highly lethal disease due to the virulence of the organisms, the severity of the complications encountered, and the predisposition to continued addiction.

Natural history of tricuspid valve endocarditis: a two dimensional echocardiographic study

Sixteen patients with tricuspid valve endocarditis were studied to define (1) what clinical or echocardiographic subsets are at risk for complications or need for tricuspid valve surgery, and (2) the long-term two dimensional echocardiographic course of tricuspid vegetations. There were 18 episodes of tricuspid endocarditis in the 16 patients; 12 patients had a history of intravenous drug abuse. Staphylococcus aureus was the most common infecting organism (11 patients). Persistent infection, cardiomegaly or radiography and right-sided heart failure were present in all patients undergoing tricuspid valve surgery and in none of the medically treated patients. Echocardiographic studies demonstrated tricuspid vegetations in 10 patients by M mode and in all 16 by two dimensional technique. Vegetation size, right ventricular enlargement and abnormal septal motion were not of prognostic significance. Two dimensional echocardiographic measurements of vegetation size correlated with surgical pathologic measurements in the four patients who underwent surgery. Serial two dimensional echocardiographic studies were available in eight patients a mean of 10.6 (range 2 to 19.5) months after the initial study: Vegetations had decreased in size or disappeared in seven patients and were essentially unchanged in one patient. It is concluded that (1) two dimensional echocardiography increases the detection of tricuspid valve vegetations and accurately estimates their size; (2) persistent infection, cardiomegaly and right-sided heart failure identify a subgroup of patients with tricuspid endocarditis who may have increased risk; (3) no M mode or two dimensional echocardiographic feature is a predictor of outcome; and (4) tricuspid valve vegetations tend to resolve with time.

Endocarditis due to group A streptococcus

In a prospective 30-month study 85 cases of endocarditis were observed at Harlem Hospital Center. Seven were due to group A beta-hemolytic streptococcus. Six of the seven were heroin users in whom solitary tricuspid valve infection occurred. Aortic valve infection occurred in the remaining patient. An incidence of 8% of group A streptococcal endocarditis was observed. An unusual local frequency of 14% of group A endocarditis among heroin addicts was noted.

Infective endocarditis in the narcotic addict

As long as the illicit use of heroin and other drugs continues in our society, infective endocarditis will remain a significant medical problem in the drug-using population. The majority of infections are produced by S. aureus, and the tricuspid valve is most commonly involved. Addicts, unlike the general population, may also develop endocarditis with a variety of gram-negative bacilli and have a higher incidence of fungal infection. The outcome of each individual infection is dependent on the prompt recognition of the underlying valvular infection and the institution of antimicrobial therapy. Infection of the tricuspid valve has a much more favorable prognosis than does infection of the aortic or mitral valves. Fungal endocarditis, and frequently gram-negative bacillary endocarditis, require valvular surgery to effect a cure.

Subacute and acute endocarditis due to Pseudomonas cepacia in heroin addicts

Five heroin addicts were treated for endocarditis caused by Pseudomonas cepacia. Two of these infections occurred in patients with no known heart disease whereas the others occurred at sites of previous endocarditis or valve prostheses. Infection was indolent in four patients but was associated with shock and skin lesions suggestive of ecthyma gangrenosum in the fifth. After failure of chloramphenicol and kanamycin, all patients were treated with a combination of sulfamethoxazole, trimethoprim and polymyxin plus heart valve resection or replacement.