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

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.