Ischemic cardiomyopathy: endomyocardial biopsy and ventriculographic evaluation of patients with congestive heart failure, dilated cardiomyopathy and coronary artery disease

Abstract

Objectives: This study was designed to define clinical and pathophysiologic similarities and differences between patients with ischemic and idiopathic dilated cardiomyopathy.

Background: Significant coronary artery disease in patients with new onset congestive heart failure due to dilated cardiomyopathy has important prognostic and therapeutic implications.

Methods: Clinical, histologic, ventriculographic and hemodynamic features of patients with dilated cardiomyopathy who underwent coronary angiography were reviewed.

Results: Patients with ischemic cardiomyopathy (n = 21) compared with those with idiopathic cardiomyopathy (n = 40) had similar presenting symptoms, durations of illness, and coronary risk factor profiles, with the exception of a greater prevalence of cigarette smoking (71% vs. 39%, p = 0.028) and male gender (100% vs. 70%, p = 0.014). Endomyocardial biopsy specimens from patients with ischemic cardiomyopathy demonstrated a greater prevalence of replacement fibrosis (48% vs. 8%, p = 0.001) and a lesser degree of histologically assessed myocyte hypertrophy (mean grade 0.5 +/- 0.7 vs. 1.3 +/- 1.3, p = 0.015). Although ventriculographically determined regional dyskinesia was present in both groups, there was a higher prevalence of two or more adjacent segments in the ischemic cardiomyopathy group (50% vs. 10%, p = 0.03). This ischemic group had hemodynamic variables associated with a worse prognosis: higher pulmonary artery wedge pressure (23 +/- 10 vs. 15 +/- 9 mm Hg, p = 0.006) and lower cardiac index (2.0 +/- 0.5 vs. 2.3 +/- 0.5 liters/min per m2, p = 0.044). Also, in this group, patients had a mean of 2.6 +/- 0.7 diseased vessels; 15 (71%) of 21 patients had triple-vessel disease and 18 (86%) of 21 had at least one occluded or suboccluded artery.

Conclusions: 1) Patients with ischemic and idiopathic cardiomyopathy may be clinically indistinguishable unless coronary angiography is performed. 2) A greater prevalence of replacement fibrosis and a lesser degree of myocardial hypertrophy in patients with ischemic cardiomyopathy may account for the greater extent of hemodynamic decompensation observed at presentation.