Evaluating Treatment Options for Patients With Infective Endocarditis

When Is It the Right Time for Surgery?

Aneil Malhotra; Bernard D Prendergast

Disclosures

Future Cardiol. 2012;8(6):847-861. 

In This Article

The Role of Surgery in Infective Endocarditis

Infective endocarditis (IE) is a serious condition with a mortality rate of nearly 30% at 1 year.[1,2] Surgery is required in up to half of acute infections and a significant proportion of those in convalescence.[3,4] Guidelines provide clear indications for when surgical intervention is indicated but these need to be adjusted to an advancing cohort of patient age with an increasing number of comorbidites.[5,6] Contemporary data in Europe suggest that surgery is now undertaken in half of IE patients, the most frequent indications being congestive cardiac failure (60%), vegetation size (48%), refractory sepsis (40%) and embolic complications (18%). However, many patients have more than one of these factors.[7] During the last three decades, valve replacement and repair have become commonplace in the management of selected complications of IE, and a reduction in the mortality of IE has been ascribed to the combination of improved antibiotic therapy and timely surgical intervention. Patient outcome is improved[8] by the involvement of a specialized IE team but expeditious surgery in carefully selected patients is also an important factor.

In active IE, long-term survival rates are approximately 70% in most series.[3,4,9–27] Assessment of surgical outcome however, is made more difficult to ascertain, since patients who are referred are frequently those with severe complications related to more virulent organisms. Conversely, those who are most seriously affected often include elderly patients with multiple comorbidities who are often deemed unfit for surgery. In general terms, prognosis is better if surgery is performed prior to progression of cardiac tissue destruction as the subsequent deterioration in the patient's preoperative condition increases the hazards of intervention. Contrary to previous belief, final outcomes are not related to the duration and intensity of prior antibiotic therapy; when surgery is clearly indicated, it should not be delayed in the vain hope that a sterile field can be achieved.

Numerous series have attempted to identify variables predictive of early and late mortality[3,4,6,10–22,28,29] and these are summarized in Table 1. However, the outcome measures used along with the variety of patient cohorts hamper interpretation. In particular, most studies have been retrospective, single-center series of patients with both native and prosthetic valve IE rather than randomized studies. Furthermore, analysis is inherently biased given the selection of patients for surgery who have an anticipated poor outcome but acceptable operative risk. Although surgery may be recommended and commonly performed for indications such as embolic complications or persistent infection, it should be recognized that there is no definitive proof of improved outcome in these situations (in contrast to congestive heart failure secondary to valvular regurgitation – see below). It has been shown that there is a significant decrease in mortality associated with early surgery in the subgroup of patients with most indications for surgery.[30] More recent analyses using sophisticated propensity scoring models have yielded conflicting results concerning the benefits of surgery,[13,20–22,28,29] with one study showing that surgery is preferably coded as a time-dependent variable; although the postoperative mortality is initially increased within 14 days, it is improved after a period of time estimated around 6 months.[29] These papers emphasize the need for further high-quality prospective studies. One such example is a recent single-center randomized controlled trial that emphasises the benefits of timely surgical intervention in patients with large vegetations and severe valvular dysfunction, even without heart failure, outweighing the risks of surgery in patients with active infection.[31] The argument for early surgery is strongly supported by this study, which provides a stimulus for designing randomized trials that will further refine the indications for and timing of surgery. Hence, clinical decision-making is difficult with overall management requiring input not only from an experienced surgical team but also from cardiologists and microbiologists.

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