prophylaxis antibiotics / HCM. By Lever and Maron

[Pam Alexson]

J Am Coll Cardiol, 2009; 54:2339-2340, doi:10.1016/j.jacc.2009.07.050
© 2009 by the American College of Cardiology Foundation

Articles by Maron, B. J.
Articles by Lever, H.


CORRESPONDENCE: LETTER TO THE EDITOR

In Defense of Antimicrobial Prophylaxis for Prevention of Infective Endocarditis in Patients With Hypertrophic Cardiomyopathy

Barry J. Maron, MD* and Harry Lever, MD
* Hypertrophic Cardiomyopathy Center, Minneapolis Heart Institute Foundation, 920 East 28th Street, Suite 620, Minneapolis, Minnesota 55407 (Email: hcm.maron@mhif.org).

We read with particular interest Bach's viewpoint editorial and critique (1) of the recent American Heart Association (AHA) revised recommendations for antimicrobial prevention of infective endocarditis (2). The "new" recommendations, which represent a striking change from the original guidelines followed for more than 50 years (1–5), are based largely on 2 risk versus benefit assumptions: 1) significant mortality or morbidity (e.g., anaphylaxis) associated with prophylactic antibiotic therapy; and 2) a lack of evidence (particularly, randomized trials) supporting the efficacy of antibiotic prophylaxis in the prevention of infective endocarditis.
Our concern regarding this debate is focused on hypertrophic cardiomyopathy (HCM) (6), a disease in which infective endocarditis is a well-documented and usually profound complication (6–9). Indeed, a survey of the PubMed archives identified 32 papers detailing the prevalence and the sometimes serious clinical consequences of endocarditis in HCM patients. While infective endocarditis is uncommon within the overall HCM population (8), when it does occur, its impact on valvular and cardiac function and risk for systemic emboli is usually consequential (7–9). Most reported cases have been associated with left ventricular outflow tract obstruction (vegetations most commonly appear on the thickened anterior mitral leaflet or adjacent surface of proximal ventricular septum), and we wish to underscore that fully 70% of HCM patients have the propensity to develop outflow obstruction at rest or with physiologic exercise (10).

We believe that the reversal of the "old" and familiar AHA guidelines on antimicrobial prophylaxis was an unfortunate mistake for patients with HCM, and indeed substantial confusion and uncertainty surrounding this issue has been created within the community of physicians, dentists, and patients with this disease. Notably, cardiovascular conditions that are relatively uncommon in clinical practice and with low event rates (such as HCM) are not amenable to the level of evidence sought by the AHA panel. However, just because it is not possible to assemble such evidence through randomized trials does not mean that a significant relationship between antibiotic treatment and prevention of infective endocarditis is nonexistent—nor does it mean that it is justified to simply negate the issue.

Perhaps this would be another matter if the potential benefit of prophylactic antibiotics were outweighed by the risks of treatment. However, as pointed out by Bach (1), and conceded in the AHA document (2), there has never been a documented anaphylactic death attributable to antibiotics administered prophylactically to prevent endocarditis. This is consistent with the authors' combined 60 years of experience with HCM, and countless patients who have taken antibiotics for that purpose.

It is obvious to us that following the most recent AHA recommendations and withholding antibiotics from patients with HCM will unavoidably have the effect of unnecessarily creating several new cases of infective endocarditis each year. We are at a loss to understand how these AHA recommendations (2), which we believe should be revised, are in the best interests of the HCM patient population.


References


1. Bach DS. Perspectives on the American College of Cardiology/American Heart Association guidelines for the prevention of infective endocarditis J Am Coll Cardiol 2009;53:1852-1854.[Abstract/Free Full Text]
2. Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis guidelines from the American Heart Association. A guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation 2007;16:1736-1754.
3. Jones TD, Baumgartner L, Bellows MT, et al. Committee on Prevention of Rheumatic Fever and Bacterial Endocarditis, American Heart Association Prevention of rheumatic fever and bacterial endocarditis through control of streptococcal infections Circulation 1955;11:317-320.[Web of Science]
4. Dajani AS, Bisno AL, Chung KJ, et al. Prevention of bacterial endocarditis: recommendations by the American Heart Association JAMA 1990;264:2919-2922.[Abstract/Free Full Text]
5. Dajani AS, Taubert KA, Wilson W, et al. Prevention of bacterial endocarditis: recommendations by the American Heart Association JAMA 1997;277:1794-1801.[Abstract/Free Full Text]
6. Maron BJ, McKenna WJ, Danielson GK, et al. American College of Cardiology/European Society of Cardiology clinical expert consensus document on hypertrophic cardiomyopathy: a report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines Committee to Develop an Expert Consensus Document on Hypertrophic Cardiomyopathy J Am Coll Cardiol 2003;42:1687-1713.[Free Full Text]
7. Roberts WC, Kishel JC, McIntosh CL, Cannon III RO, Maron BJ. Severe mitral or aortic valve regurgitation, or both, requiring valve replacement for infective endocarditis complicating hypertrophic cardiomyopathy J Am Coll Cardiol 1992;19:365-371.[Abstract]
8. Spirito P, Rapezzi C, Bellone P, et al. Infective endocarditis in hypertrophic cardiomyopathy: prevalence, incidence, and indications for antibiotic prophylaxis Circulation 1999;99:2132-2137.[Abstract/Free Full Text]
9. Alessandri N, Pannarale G, del Monte F, Moretti F, Marino B, Reale A. Hypertrophic obstructive cardiomyopathy and infective endocarditis: a report of seven cases and a review of the literature Eur Heart J 1990;11:1041-1048.[Abstract/Free Full Text]
10. Maron MS, Olivotto I, Zenovich AG, et al. Hypertrophic cardiomyopathy is predominantly a disease of left ventricular outflow tract obstruction Circulation 2006;114:2232-2239.[Abstract/Free Full Text]


Related Article

Reply
David S. Bach
J. Am. Coll. Cardiol. 2009 54: 2340.

[hocmdoug]

Pam,

Thanks so much for posting this letter to the editor/article.:cool:

[Huntington]

Dr. Ted Abraham appears to be on board with Drs. Lever and Maron as in October 2009 he had no qualms in advising me to obtain prophylactic antibiotics.

[mtlieb]

Thanks Pam,

I'm glad to see Drs. Lever and Maron go on record with their objections to the revised AHA recommendations regarding antibiotic prophylaxis as this will be helpful to HCM patients and our doctors who may be confused by this issue. I can use this as a 'note from my specialist' of sorts should anyone feel that I should not pre-medicate.

I was surprised to read the 70% figure with regard to prevalence of obstruction.

Jim

[LibrarianGirl]

I understand the need for antibiotic prophylaxis in the HCM population, but I urge all of you to talk to your doctors about the type and dose amount of antibiotic that you are prescribed.

Last year I went through a "scare" after getting an ICD and thought I had endocarditis. In actuality I had acrylic fingernails removed which resulted in damage to my nails.... but me being a worrywort I thought maybe it was the dark spots on fingernails associated with endocarditis. I went to the ER and was given two large doses of antibiotics on subsequent days "just to be on the safe side."

Just being on the safe side has made my life miserable for going on 7 months now, with the end nowhere in sight. Many people (I was one of them) don't think about the consequences of taking antibiotics, but they can have side effects just like any other medication. I assume that's why the AHA made this decision.... because antibiotics are currently handed out like candy by many in the medical profession with no thought to possible repercussions.

Many antibiotics can be ototoxic.... dangerous to the ears. My neurotologist (inner ear specialist) believes that these large doses of antibiotics permanently damaged my inner ears. I have been dizzy since June. My head is constantly heavy and fuzzy. My vision is blurry. I was lucky to have been on summer vacation when this came about or else I would not have been able to work for the first month and likely would have lost my job (I could barely stand, let alone walk or drive). I am now doing physical therapy to help my brain and body compensate for the damage to my vestibular system. I am 28 years old and I will probably never get back normal balance. This has been by far the most difficult and trying experience of my life.

Yes, I am well aware that endocarditis would be "worse" and is potentially fatal, but I still feel that physicians need to be more careful about the distribution of antibiotics. I understand that my situation is different than taking antibiotics before a dental appointment... for one the dose I had was much larger - but I can assure you that in the future I will question and investigate any medicine I am prescribed - especially antibiotics.

[mtlieb]

I wanted to re-open the prophylactic antibiotic discussion and ask a question of the group. Do you pre-medicate for all dental procedures or just the more invasive ones like root canal, extractions, etc? As I have become allergic and/or intolerant to more and more antibiotics over the years I really only want to use them now when absolutely necessary. Recently I have stopped using them for simple dental procedures like small fillings and adjusting crowns, etc.

[gfox42]

I premedicate even for cleanings. But then I have no problems with the antibiotics.

Gordon

[Deedee]

Now you are just hunting down old threads, hehe!

I don't premedicate at all for the dentist. I just skip the adrenalin in the shots and that's about it. I suppose if something major was going on I'd reconsider tho.

[mandksiders]

I premedicate for anything at the dentist, cleanings included.

-Kaye

[mbcube]

I premedicate for all dental work. I did find I am sensitive to some anitbiotics and developed a facial rash so I switch meds & very happy not to have this happen. Having red splotchy skin for 2 weeks for a simple cleaning or a filling was annoying!

[Largehearted]

I pre-medicate for everything dental too.

Leon

[Toogoofy317]

Right now we are kinda on the sesaw of antibiotics my immune system is krap and with all of the infections my primay is having reservations because if I ever came up with a resistant strand I'd be in real trouble. When the port was infected in January we were all perplexed when it was a combo yeast/staph infection. After we thought I cleared it up I ended up with myocarditis which got me a helicopter flight to Downtown. I'm still feeling weakness from it! For my supposed surgery I was given 1 gram of oh can't remember they called off the surgery 7.5 hours later. So, more needless antibiotics and a week of diarrhea! That really aggrevates the Crohn's disease which throws in its own wrench because one of the treatments is constant anti-biotics to keep the bacteria down in the intestines. Ugh, I don't think anyone has a clue anymore!

Mary

[Cynaburst]

I always premedicate before I go to the dentist, even for cleanings. I am very careful when I have any medical procedure to make sure that I don't need any antibiotic.

[mamoss]

As w/everything else, this boils down to being a personal decision we will each make, hopefully armed w/full disclosure and careful consideration of risks and benefits. Yeah right....as if anything could be that black and white. I emphatically do not take antiobiotics for dentist visit. To my way of thinking, if I were going to take antibiotics to go to the dentist, then I might as well take them every day before flossing, or diggingin the garden, or scrubbing the toilets. I feel far more threatened by resistant bacteria, than by the everyday germs we encounter. Of course when it comes time for endoscopic procedures, I believe antibiotics are de riguer. Perhaps inconsistent, but that's my strategy and I'm sticking with it.

[hocmdoug]

Yup, teeth cleanings too.

Interesting point about flossing....I use a little antiseptic mouthwash after flossing if I happen to draw any blood.