Medical Procedures and Heart Valve Infection

There are not free lunches! It is not uncommon to think that getting a procedure is better than not getting one, however, all procedures are associated with risks. For each procedure, the risk and benefits need to be carefully assessed before making a decision to undergo a procedure or not. Often having a procedure has greater benefits than risks, or so we assume.

While the benefits of a procedure are often clear, for example detection of coronary diseases when deciding about cardiac catheterization, the risks are not as well-studied. The list of risks associated with a procedure almost always includes risk of death and injury to some organ(s) but the actual incidence of these adverse events is usually poorly known, especially for for adverse events that are not immediately followed by the procedure (that is, there is lag-time between a procedure and associated adverse events). The more time lapses between the procedure and an adverse event, the difficult it is to ascribe adverse event to the procedure; generally so many other things, including additional procedures, happen in-between for diagnostic or therapeutic reasons.

One aspect of this issue is nicely addressed in an article published in the Journal of the American College of Cardiology where authors identified all adult patients treated for endocarditis in hospitals in Sweden and compared the occurrence of invasive medical procedures 12 weeks before endocarditis with a corresponding 12-week time period exactly 1 year earlier.

Of the 7,013 cases of infective endocarditis during the study period, several were strongly associated with cardiovascular procedures, especially coronary artery bypass grafting; procedures of the skin and management of wounds; transfusion; dialysis; bone marrow puncture; and some endoscopies, particularly bronchoscopy. A particularly interesting finding, that makes sense, is that the risk of infective endocarditis was higher if patient had a procedure while hospitalized than when patient had that procedure in outpatient setting. One way to look at this is to think that procedures should be done in outpatient setting but the converse is also possible (and more likely) that patients admitted to the hospital are sicker and hence are at higher risk of adverse effects.