Abstract 4842: Diagnostic Contribute of Left Ventricular Endomyocardial Biopsy in Patients with Clinical Phenotype of Hypertrophic Cardiomyopathy
Introduction: The definition of hypertrophic cardiomyopathy includes heterogenous entities with different treatment options and prognosis. Non invasive imaging techniques are often inadequate for a differential diagnosis while the role of endomyocardial biopsy is still debated.
Hypothesis: We hypothesized that left ventricular endomyocardial biopsy (LVEMB) may have a role for the histologic differentiation of patients with clinical phenotype of hypertrophic cardiomyopathy, affecting patients’ treatment and prognosis.
Methods: From January 1988 to May 2008, 139 consecutive patients (91 M, 48 F, mean age 44.2±15.9 ys) with unexplained left ventricular hypertrophy (maximal wall thickness ≥ 15 mm) and normal or elevated QRS voltages, underwent cardiac catheterisation, coronary angiography and LVEMB. Family history without histological diagnosis was present in 15% of cases. Endomyocardial samples (≥ 4 specimens per patient, ≥ 3 mm2 each) were processed for histology, histochemistry and transmission electron microscopy.
Results: LVEMB was diagnostic in all cases. Histology showed severely hypertrophied cardiomyocytes, often in disarray, consistent with hypertrophic cardiomyopathy in 114 patients (82%). In 17 patients (12.2%) histology showed a myocardial storage disease presenting as primary cardiomyopathy, consisting in Fabry disease in 13 patients (9.3%), and in glycogen-storage disease in 4 (2.9%), due to acid maltase deficiency in 1 case, LAMP2 mutation in 1 and PRKAG2 mutation in 1. In 8 patients (5.8%) a myocardial infiltrative disease, consisting in amyloidosis (5 cases, 3.6 %) hemochromatosis (2 cases, 1.4 %), and sarcoidosis (1 case, 0.7%) was diagnosed. The procedure had non fatal low rate complications (vasovagal reaction to arterial puncture in 2 %, local bleeding in 1 %, systemic embolization with transient brain ischemia in 0,7%).
Conclusions: LVEMB recognises unpredictable specific histologic changes in up to 18% of patients with clinical phenotype of hypertrophic cardiomyopathy. Particularly for storage and infiltrative diseases specific therapy may modify patients’ clinical outcome.