Endomyocardial biopsy (EMB) should be performed in the setting of unexplained, new-onset heart failure of <2 weeks' duration associated with a normal-sized or dilated left ventricle in addition to hemodynamic compromise. Class of Recommendation I, Level of Evidence B.
EMB should be performed in the setting of unexplained new-onset heart failure of 2 weeks' to 3 months' duration associated with a dilated left ventricle and new ventricular arrhythmias, Mobitz type II second- or third-degree atrioventricular (AV) heart block, or failure to respond to usual care within 1 to 2 weeks. Class of Recommendation I, Level of Evidence B.
EMB is reasonable in the clinical setting of unexplained heart failure of >3 months' duration associated with a dilated left ventricle and new ventricular arrhythmias, Mobitz type II second- or third-degree AV heart block, or failure to respond to usual care within 1 to 2 weeks. Class of Recommendation IIa, Level of Evidence C.
EMB is reasonable in the setting of unexplained heart failure associated with a dilated cardiomyopathy (DCM) of any duration that is associated with suspected allergic reaction in addition to eosinophilia. Class of Recommendation IIa, Level of Evidence C.
EMB is reasonable in the setting of unexplained heart failure associated with suspected anthracycline cardiomyopathy. Class of Recommendation IIa, Level of Evidence C.
EMB is reasonable in the setting of heart failure associated with unexplained restrictive cardiomyopathy. Class of Recommendation IIa, Level of Evidence C.
EMB is reasonable in the setting of suspected cardiac tumors, with the exception of typical myxomas. Class of Recommendation IIa, Level of Evidence C.
EMB is reasonable in the setting of unexplained cardiomyopathy in children. Class of Recommendation IIa, Level of Evidence C.
EMB may be considered in the setting of unexplained, new-onset heart failure of 2 weeks' to 3 months' duration associated with a dilated left ventricle, without new ventricular arrhythmias or Mobitz type II second- or third-degree AV heart block, that responds to usual care within 1 to 2 weeks. Class of Recommendation IIb, Level of Evidence B.
EMB may be considered in the setting of unexplained heart failure of >3 months' duration associated with a dilated left ventricle, without new ventricular arrhythmias or Mobitz type II second- or third-degree AV heart block, that responds to usual care within 1 to 2 weeks. Class of Recommendation IIb, Level of Evidence C.
EMB may be considered in the setting of heart failure associated with unexplained hypertrophic cardiomyopathy (HCM). Class of Recommendation IIb, Level of Evidence C.
EMB may be considered in the setting of suspected arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Class of Recommendation IIb, Level of Evidence C.
EMB may be considered in the setting of unexplained ventricular arrhythmias. Class of Recommendation IIb, Level of Evidence C.
EMB should not be performed in the setting of unexplained atrial fibrillation. Class of Recommendation III, Level of Evidence C.
Definitions:
Levels of Evidence
Level A (highest): Multiple randomized clinical trials.
Level B (intermediate): Limited number of randomized trials, nonrandomized studies, and registries
Level C (lowest): Primarily expert consensus.
Classification of Recommendations
Class I: Conditions for which there is evidence or there is general agreement that a given procedure is beneficial, useful, and effective
Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment
Class IIa: Conditions for which the weight of evidence/opinion is in favor of usefulness/efficacy
Class IIb: Conditions for which usefulness/efficacy is less well established by evidence/opinion
Class III: Conditions for which there is evidence and/or general agreement that a procedure/treatment is not useful/effective and in some cases may be harmful.
