I'm pleased to be here as part of Congress 2023. I'm gonna be speaking about endocarditis and cardiovascular infections and their management and updates in the care for patients. My name is Megan Hicks. I'm assistant professor of anesthesiology and I practice cardiothoracic anesthesiology as well as critical care at Atrium Health Wake Forest Baptist in Winston-Salem. And I have no conflicts to disclose. These are the objectives for my talk, including reviewing the current consensus guidelines, talking about updates on antibiotic therapy as well as timing for surgical intervention, types of surgical intervention, including repair versus replace, as well as special considerations for certain populations as well as alternative percutaneous therapies that have become available. These are the three main consensus guidelines for this patient population with infective endocarditis with one endorsed by the IDSA as well as a Cochran review, which both referenced the antibiotic therapies that are indicated for these patients, as well as the ACC-AHA clinical practice guideline, which is the most current of these three documents. The mainstay of infective endocarditis therapy is obviously high dose, long duration beta-lactam antibiotic therapy with native valve endocarditis requiring a slightly shorter duration of four weeks compared to prosthetic valve endocarditis, which requires at least six weeks of therapy. There are some caveats that require sometimes only two weeks of therapy, and that includes primarily right-sided infective endocarditis that's responsive to therapy, as well as combination therapy for VIRD and STREP of the native valve in both of these cases. Postoperative therapy is one of the variations where if the valve culture comes back negative on the tissue removed interoperatively, then you can complete antibiotics two weeks after the surgery. However, if your culture returns positive, the recommendation is that you would restart the entire antibiotic series, that being four or six weeks depending on the valve that was removed. This slide is meant to highlight some of the more recent changes in antibiotic recommendations with one of the most common being that MSSA-confirmed endocarditis no longer needs immunoglycoside therapy with gentamicin. Rifampin used to be one of the mainstays as an adjunct therapy for staph native valve endocarditis, but this is no longer a recommendation except in certain circumstances. Enterococcus is a organism that is recommended to have double lactam therapy or beta-lactam and gentamicin combination therapy, though the ceftriaxone availability in the single daily dosing is an alternative therapy that's been presented and has been shown to be effective. One of the newer things that is coming online is the option for partial PO therapy for patients. In patients who have left-sided native valve disease and after 10 to 14 days of confirmed improvement in the inpatient setting, there is some data to support conversion to outpatient therapy by mouth rather than IV therapy, which is obviously safer and more convenient for patients. The exception to the antibiotic therapy durations that we've spoken about are patients who have fungal endocarditis. They're almost certainly going to be patients who have an operative intervention, but lifelong antibiotic suppression is indicated in these patients, whereas others should at some point complete antibiotic therapy. More than 50% of patients with acute infective endocarditis will need surgical intervention. The STS has developed a risk endocarditis or risk e-scoring system, which helps to prioritize which patients need to undergo therapy in the timeline for when that needs to be done. But for all locations, there are three common surgical indications. Primarily, highly resistant or known fastidious organisms, including fungi, multiple drug-resistant organisms, as well as non-HASEC GNRs, so that includes pseudomonas, are almost universally recommended to have a surgical intervention. Patients who also have a persistent bacteremia for more than five to seven days, despite antibiotic therapy that is appropriate for their organism, are also indicated to have therapy and you do not need clearance of the bacteremia prior to surgical intervention. The other population is those who have recurrent emboli, be that to spleen, lung, brain, whatever, despite antibiotic therapy. If they continue to have new embolism, they are indicated to have surgery. While there is obviously urgency to surgical intervention for many of these patients, there are only a few who truly need emergency surgery. And those are patients who should go to the operating room within 24 to 48 hours, or those who are in acute cardiogenic shock due to valvular dysfunction from their valve infection, as well as those with a large mobile vegetation that is at imminent risk of embolism. And this is not universal between all three sets of guidelines, but is thought to be a threshold of about 20 millimeters on either side of the heart that need to go urgently to the operating room. From here, we're gonna further clarify the guidelines for specific valvular disorders. So these are patients who have prosthetic valve endocarditis. Patients should have surgical intervention if they have heart failure from valve dehiscence, fistula formation, or severe valvular dysfunction of a prosthetic valve. Also, if they have an abscess, heart block, or destructive penetrating lesion, they have relapse of a prosthetic valve endocarditis, or if they have a mobile vegetation measuring greater than 10 millimeters in size. Similar to those with prosthetic valve endocarditis, patients with left-sided native valve endocarditis have surgical indication if they have valve dysfunction with severe heart failure symptoms. Also, if they have abscess, heart block, or destructive penetrating lesions surrounding the valve, those with persistent or enlarging vegetations despite appropriate antibiotic therapy, mobile vegetations greater than 10 millimeters with severe regurgitation of their valve, or vegetations greater than 10 millimeters specifically on the anterior leaflet of the mitral valve due to the higher likelihood of embolization. Given that right-sided native valve endocarditis is rarer and often associated with those who abuse IV drugs, there are only specific indications, and those are patients who have specific complications, including right heart failure due to severe tricuspid regurgitation due to poor medical response with appropriate antibiotic therapy, as well as tricuspid valve vegetations greater than 20 millimeters in size. There is significant debate on whether repair versus replacement is indicated for patients specifically in the IV drug abuse population where there is concern for need for valve replacement again in the future with reinfection. The data has shown that both in tricuspid and mitral valve endocarditis surgery, repair is superior with the rationale that there's no prosthetic material that's needed to be placed, which is higher risk for reinfection. There's also no need for reoperation for valve dysfunction given that our bioprosthetic valves generally last only 10 to 15 years. Perioperatively and long-term, there is better survival for patients undergoing repair and a lower risk of recurrent infection. And again, this holds both in the short and the long-term as a benefit for these patients. There is some data that suggests that allografts may be better for aortic valve endocarditis, but this is rarely actually employed. Patients who have suffered strokes as a result of endocarditis are a contentious population as far as surgical planning. And that's because stroke is an independent risk factor for mortality in the perioperative period for these patients. However, there is data to support intervention in these patients in specific timing as far as guidelines. So for patients who have suffered a cardioembolic phenomenon and that would be the majority of patients having endocarditis, obviously the concern is hemorrhagic conversion of their stroke with heparinization at the systemic level needed for cardiopulmonary bypass. Data suggests that there are similar to maybe better outcomes for early intervention, that being surgery within the first seven days of diagnosis of strokes. And so the recommendation is actually to go ahead and proceed in patients who have no known documented hemorrhage. For patients with hemorrhagic stroke, however, there is a prohibitively high risk for surgical intervention in heparinization for at least four weeks. And part of that concern is obviously expansion of the hemorrhage that's existing, but also the concern for the presence of mycotic aneurysms contributing to these hemorrhages, which may not be immediately recognized in the immediate period of diagnosis. The recommendation for patients who have mechanical valve endocarditis is that you should hold their anticoagulation for two weeks if they suffer an embolic stroke. And in contrast to patients who have a stroke from regular cardiomyoblic disease, that bit non-infectious disease, there is no recommendation in endocarditis to give aspirin or antiplatelet medications because there is not a benefit that has been shown. One of the things that has been noted with the increase in endocarditis is the increased prevalence of patients who abuse IV drugs needing surgery. And there certainly is frequently conversation regarding the timing or ability to offer surgery for these patients. The mainstay of the therapeutic intervention for these patients is that they must be referred for substance abuse therapy. There are certainly ethical considerations to be had, and most surgeons will ask that patients have a commitment in a variety of ways to being clean and not continuing to use substances. Though again, there are ethical considerations with how you can actually enforce that. But the general theme in patients who do have a history of IV drug use is to avoid surgery whenever possible and try to get antibiotic clearance and give them time to be clean. And so angiovac therapy that we'll discuss briefly in just a moment is a certain option for these patients. There is no difference in mortality for these patients in intervening in the first three months or waiting six months to do intervention. There's certainly a three to six month relapse window that can happen if patients are intervened upon early. There are no clear indications or guidelines for reoperations in these patients. So say you have a patient who's already had a valve replacement who then has prostatic valve endocarditis due to IV substance abuse, that there is no clear guideline to say that that patient should or should not have intervention if they're otherwise a good surgical candidate. And so ultimately it is left up to the independent surgeon to make that decision. So in patients that are poor surgical candidates or otherwise don't meet surgical indications, there is a role for percutaneous therapies to at least decrease endocarditis burden and hopefully clear their bacteremia. So angiovac is a surgical system where you place an angiovac cannula into the right atrium, often directed towards the tricuspid valve and sometimes towards the septum or wherever your endocarditis or clot burden is. This is also used just for thrombus. And then there is a drainage cannula from that angiovac cannula into a circuit that is often a ECMO circuit with a centrifugal pump. And then there is a return cannula placed back into the femoral venous side. And this system is used classically for right-sided vegetations, but there has been some deployment recently across the septum for mitral valve disease. And this may become an increasingly prevalent intervention. It is obviously effective for debulking and specifically when surgical risk is prohibitive. Data suggests that 90% of patients undergoing angiovac will have removal of greater than 50% of their endocarditis burden with 80% or more of patients clearing their cultures after this procedure. Unfortunately, because you're applying suction to a valve and the leaflets of the tricuspid valve are already quite fragile, this often worsens tricuspid regurgitation. And you may see worse functional status in these patients, but improved clearance. The goal in angiovac is really to give time for intervention. Ideally, you can spare surgery if able, but also to give patients time to go through any recovery that is needed, especially in IV drug use patients. My talk is mostly focused on actual valvular endocarditis, but there is certainly an increasing burden of cardiac devices being placed into patients over the last decade or so. And with that comes colonization or endocarditis with lesions and vegetations actually attached to intracardiac devices. And so laser lead extraction has become a mainstay of therapy in these populations. It is recommended to have intervention within really about the first 48 hours of diagnosis to minimize spread and plaque formation. But what this actually is, is a laser sheath that is placed encapsulating the patient's lead. As you can see, there's a sheath over the patient's existing lead. It uses cool cutting xenon lasers to lyse scar tissue under counter traction on the lead itself. And that facilitates lead removal without an intracardiac procedure or surgical procedure. It's done transcutaneously and is often an approach from the femoral side, but can be certainly done from the subclavian or from the pocket itself. There are worse outcomes in patients undergoing lead extraction for endocarditis or infection when compared to patients undergoing this procedure for fractured leads. But this outcome is actually worse when the procedure is delayed. And so early intervention is key. Patients with strep infections are known to have higher risk with laser lead extraction. And certainly the main consideration and concern for laser lead complications is that if the lead is dislodged without actually being completely lysed, that you do have a risk for massive hemorrhage and tamponade. So these need to be done under close monitoring with surgical standby in case there is complication. I very much appreciate the opportunity to speak with you today. And I'm open to questions by email if that would be helpful. Thank you so much.

endocarditis

antibiotic therapy

surgical intervention

consensus guidelines

percutaneous therapies