Interobserver variability in the pathologic interpretation of endomyocardial biopsy results

Area of Science:

• Cardiology
• Pathology

Background:

• Dilated cardiomyopathy diagnosis relies on endomyocardial biopsy, but its role in detecting myocarditis and assessing prognosis remains debated.
• High interobserver variability among pathologists may contribute to conflicting reports on biopsy interpretation.

Purpose of the Study:

• To evaluate the interobserver variability in the interpretation of endomyocardial biopsy specimens from patients with dilated cardiomyopathy.
• To assess the consistency of diagnosing myocarditis and quantifying histological features.

Main Methods:

• Seven cardiac pathologists independently reviewed biopsy specimens from 16 dilated cardiomyopathy patients.
• Histological features assessed included fibrosis, hypertrophy, nuclear changes (0-3+ scale), lymphocyte count, and myocarditis presence.

Main Results:

• Wide ranges in prevalence were observed for significant fibrosis (25-69%), hypertrophy (19-88%), nuclear changes (31-94%), and abnormal lymphocyte counts (0-38%).
• Definite or possible myocarditis was identified in 11 patients, but agreement among pathologists was low (3 pathologists agreed on 3 cases, 2 pathologists agreed on 5 cases).
• Myocarditis was diagnosed by a single pathologist in 3 cases.

Conclusions:

• Significant interobserver variability exists in the interpretation of endomyocardial biopsies for dilated cardiomyopathy.
• Quantitative and standardized diagnostic methods are necessary to improve consistency in evaluating these biopsy specimens.