Infective endocarditis (IE) is a devastating complication of heart valve disease that, left untreated, can be fatal. Management requires a multidisciplinary approach, and many of the respective medical societies that represent the participating specialties have developed guidelines. Now, the American Association for Thoracic Surgery has published “Consensus Guidelines for the Surgical Treatment of Infective Endocarditis” to guide thoracic and cardiovascular surgeons in making decisions of when to operate in cases of IE (J Thorac Cardiovasc Surg. 2017 Jan 24. doi: 10.1016/j.jtcvs.2016.09.093).
Dr. Gösta B. Pettersson
The rationale for developing the guidelines is a growing prevalence of IE, including in patients with normal valves and no previous diagnosis of heart disease. “These new AATS consensus guidelines primarily address questions related to active and suspected active IE affective valves and intracardiac structures,” Dr. Pettersson and his coauthors said. The AATS guidelines for infective endocarditis address complications including risk of embolism and the timing of surgery in patients with neurological complications, while acknowledging the the need for additional research into these topics.* “It is understood that surgery is beneficial only if the patient’s complications and other comorbidities do not preclude survival and meaningful recovery,” the guideline authors said.
The guidelines confirm the team approach for managing patients with IE. The team should include cardiology, infectious disease, cardiac surgery, and other specialties needed to handle IE-related complications (class of recommendation [COR] I, level of evidence [LOE] B). Before surgery, the surgeon should know the patient is on effective antimicrobial therapy (COR I, LOE B). Transesophageal echocardiography (TEE) is indicated to yield the clearest understanding of the pathology (COR I, LOE B).
Dr. Pettersson and the guideline writing team also clarified indications for surgery in patients with IE. They include when valve dysfunction causes heart failure (COR I, LOE B); when, after a full course of antibiotics, the patient has signs of heart block, annular or aortic abscess or destructive penetrating lesions (COR I, LOE B); and in the setting of recurrent emboli and persistent vegetations despite appropriate antibiotic therapy (COR IIA, LOE B).
The guideline writers acknowledged potential disagreement between the AATS guidelines and those of the American College of Cardiology/American Heart Association with regard to early surgery in IE. Debate surrounds whether to operate early or wait for symptoms of heart failure to manifest in patients with native valve endocarditis (NVE). The AATS guideline authors cite work by Duk-Hyun Kang, MD, PhD, and coauthors in South Korea (N Engl J Med. 2012;366;2466-73) and others advocating for early surgery. “For this reason, once a surgical indication is evident, surgery should not be delayed,” Dr. Pettersson and his coauthors said.
Several conditions can influence the timing of surgery. Patients with cerebral mycotic aneurysm should be managed closely with neurology or neurosurgery (COR I, LOE C). Patients with a recent intracranial hemorrhage should wait at least 3 weeks for surgery (COR IIA, LOE B), but those with nonhemorrhagic strokes could go in for urgent surgery (COR IIA, LOE B). Brain imaging is indicated for IE patients with neurological symptoms (COR I, LOE B), but anticoagulation management requires a nuanced approach that takes all risks and benefits into consideration (COR I, LOE C).
Key steps during surgery involve mandatory intraoperative TEE (COR I, LOE B), median sternotomy with few exceptions (COR I, LOE B), and radical debridement and removal of all infected and necrotic tissue (COR I, LOE B). The writers also provided four guidelines for reconstruction and valve replacement:
- Repair when possible for patients with NVE (COR I, LOE B).
- When replacement is indicated, the surgeon should base valve choice on normal criteria – age, life expectancy, comorbidities, and expected compliance with anticoagulation (COR I, LOE B).
- Avoid use of mechanical valves in patients with intracranial bleeding or who have had a major stroke (COR IIA, LOE C).
- In patients with invasive disease and deconstruction, reconstruction should depend on the involved valve, severity of destruction, and available options for cardiac reconstruction (COR I, LOE B).
The AATS guidelines also challenge conventional thinking on the practice of soaking a gel-impregnated graft with antimicrobials targeting a specific organism. “We found no evidence to support this practice,” Dr. Pettersson and his coauthors said (COR IIB, LOE B). They came to the same conclusion with regard to the use of local antimicrobials or antiseptics during irrigation after debridement and local injection of antimicrobials around the infected area (COR I, LOE C).
The guidelines provide direction on a host of other surgical issues in IE: use of aortic valve grafts; when to remove or replace noninfected grafts; when to remove pacemakers; the role of drainage; postoperative management; follow-up; and additional screening. They also shed insight into what the guideline authors call “residual controversies,” including surgery for injection drug users (use “all available resources and options for drug rehabilitation”) and dialysis patients (“it is reasonable to offer surgery when the additional burden of comorbidities is not overwhelming”). They also acknowledge seven different scenarios that lack clear evidence for intervention but require the surgeon to determine the need for surgery, ranging from timing of surgery for IE in patients with neurologic complications to how to treat patients with functional valve issues after being cured of IE.
The guideline writers acknowledged that institutional funds supported the work. Dr. Pettersson had no financial relationships to disclose.
*Correction 5/172017: It was incorrectly stated that these complications were not addressed in the guidelines due to lack of evidence