Endomyocardial Biopsy Guidelines
Bernard J Gersh MB ChB DPhil: I am Bernard Gersh at the Mayo Clinic, and with me is Dr Leslie Cooper who is a professor of medicine at Mayo, director of the vascular center, and, very appropriate to the topic for today, he was also the chair of the American Heart Association/American College of Cardiology and European Society Guidelines on the role of endomyocardial biopsy in cardiovascular diseases.
Welcome, Les. You were just telling me before we started that chairing that committee was very interesting because of the wide divergence of opinions and ways in which we practice. Do you want to just elaborate on that?
Leslie T Cooper Jr MD: When I entered that job, it was with some skepticism, and it turned out that we worked very well as a committee over the course of 18 months. We started with a wide divergence of opinion about the best role for endomyocardial biopsy in certain cardiovascular diseases, but the committee was able to come to consensus on most areas. In fact, we were for the first time able to organize the literature by clinical scenario and thereby make 14 specific recommendations for different clinical scenarios.
Dr Gersh: Having recently gone through the guidelines process with hypertrophic cardiomyopathy, it is a difficult process. It has been said that a camel could only have been invented by a committee; nature would never have created something like that. But we also came to a very reasonable document in the end, and it was a great learning process.
So what are the current recommendations for endomyocardial biopsy in the broad realm of cardiovascular diseases?
Indications for Biopsy
Dr Cooper: Two clinical scenarios have a class 1 indication, which means you should perform endomyocardial biopsy. They are new-onset dilated cardiomyopathy of less than six months' duration, which is associated with either a failure to respond to usual care, sustained or symptomatic ventricular tachycardia [VT], or high-degree heart block. That scenario is a class 1 indication because it may indicate giant-cell myocarditis.
Dr Gersh: So the VT doesn't have to be of six months' duration. It's disease of less than six months' duration or disease with the presence of VT or heart block.
Dr Cooper: That's right, and this is not asymptomatic or nonsustained short runs of VT. This is sustained and/or symptomatic ventricular tachycardia.
Dr Gersh: And the second indication?
Dr Cooper: The second is fulminant heart failure associated with hemodynamic collapse requiring inotropes or balloon-pump support in the setting of a nonischemic cardiomyopathy. That phenotype of fulminant myocarditis deserves a biopsy for prognostic reasons.
Dr Gersh: That implies a very short duration.
Dr Cooper: Less than two weeks, usually.
Dr Gersh: For indication number 1, why is it so important to diagnose giant-cell myocarditis?
Dr Cooper: Giant-cell myocarditis is almost always fatal or requires a heart transplant and responds to multidrug immunosuppression, usually involving calcineurin inhibitor such as cyclosporine.
Dr Gersh: What is the mortality rate in the people treated with that? You said it is almost always fatal.
Dr Cooper: The risk for death or transplant in our retrospective series from the New England Journal of Medicine was 50% at one year. In the prospective series, the risk for death or transplant was 21% at one year. So that's a 79% survival without transplant.
Dr Gersh: So it is pretty good, right? Anecdotally, I have seen some spectacular cases of patients who were very ill and who have recovered or at least partly recovered.
Dr Gersh: Indication number 2 is fulminant heart failure. You are biopsying for prognosis. Can you just elaborate a bit?
Dr Cooper: The first group to describe the good prognosis of fulminant lymphocytic myocarditis was from Johns Hopkins. The late Ken Baughman described that clinical pathological scenario, and if you have lymphocytic myocarditis in that setting, the likelihood of full recovery of heart function (if you survive the initial injury) is excellent, a very good recovery rate over a relatively short period of time.
In addition, it's suggested that if you require mechanical circulatory support—a ventricular assist device—you have a pretty good chance of weaning; a bridge to recovery.
Dr Gersh: What are some of the other prognostic indicators on biopsy? Sure, you can see giant cells. What else?
Dr Cooper: If you get granulomas such as cardiac sarcoid, the consensus recommendation is for immunosuppressive therapy, usually with steroids, and often with a second agent. Another possibility is eosinophilic myocarditis, which responds beautifully to steroids in many cases.
Dr Gersh: Is that often a drug hypersensitivity or hypersensitivity to some other agent?
Dr Cooper: Yes, in developed countries, the most common reason would be a hypersensitivity reaction to a drug.
Dr Gersh: And in the developing world, parasites or whatever underlies Loeffler's eosinophilic myocarditis. Is the complication rate any different in these acutely ill patients with dilated thin wall ventricles? Obviously, the complications are related to vascular excess and obviously perforation. Is it higher in this setting than, say, in the transplant setting?
Dr Cooper: It is. In the posttransplant heart, the risk for perforation is quite low.
Dr Gersh: How low? About 1%?
Dr Cooper: Much lower. The risk for perforation in native hearts is about one in 250 and the risk for death from perforation is about one in four of those or one in 1000, and that's in a broad selection of centers. In centers where you have a great deal of expertise in the procedure, the risk is probably lower. The overall risk for minor complications such as transient bundle-branch block or a hematoma at the access site would be about 6%.
Dr Gersh: What about perforations?
Dr Cooper: The perforation rate is one in 250.
Dr Gersh: So it's pretty low.
Dr Cooper: Yes. I think of it as being roughly equivalent to the risk associated with a diagnostic coronary angiogram in experienced hands.
Cite this: Bernard J. Gersh, Leslie T Cooper. Endomyocardial Biopsy in Cardiovascular Disease - Medscape - Jan 06, 2014.