PATHOLOGICAL SUBSTRATES AND CLINICAL CORRELATES OF CORONARY-ARTERY DISEASE AND CHRONIC CONGESTIVE-HEART-FAILURE REQUIRING CARDIAC TRANSPLANTATION

To investigate the pathologic landmarks of ischemic cardiomyopathy, we studied the hearts of 42 nondiabetic patients with coronary artery disease and chronic congestive heart failure who had undergone cardiac transplantation. The mean age of patients was 50 +/- 9 years, and the mean duration of coronary artery disease from onset of symptoms was 80 +/- 40 months. Onset of dilatation and congestive heart failure dated 19 +/- 7 months before transplantation. Previous myocardial infarction was single in 27 patients, multiple in 14, and absent in one. Heart weight ranged from 280 to 850 g (490 +/- 135 g). Spared myocardium had a mean thickness of 13 +/- 3 mm (range, 7 to 23 mm) and constituted two thirds of total left ventricle mass. Ventricular transmural scars were mainly anterior (78%) and apical (100%). Sixty percent of hearts had multiple noncontiguous scarred areas. All ventricular walls with some scar moved abnormally on angiography (mostly akinesia and dyskinesia). In addition, 26 of 30 full-length spared ventricular segments also showed impaired wall motion on angiography (mostly hypokinesia). On histologic morphometric study, mean myocyte diameter was 18 +/- 2-mu-m in full-thickness spared myocardium and 20 +/- 3-mu-m in partially spared areas. Endocardium was thinner in intact wall segments (119 +/- 183-mu-m) than in segments with some intramural fibrosis (366 +/- 519-mu-m). One-, two-, and three-vessel disease was found in seven, 10, and 25 patients, respectively. The left anterior descending artery was most frequently involved (40 patients, or 95%), followed by the right coronary artery (33 patients, or 78%) and left circumflex (28 patients, or 67%). Anterior descending coronary artery was diffusely narrowed in both proximal and middistal portions in 30 cases, right coronary artery in 24, and left circumflex in 17. Coronary arteriography, performed 8 +/- 5 months prior to transplantations, correctly depicted proximal critical lesions, while middistal narrowings associated with proximal ones were frequently missed. A scoring system identified both multivessel disease and multisegment narrowings of each vessel. Angiographic score was much lower than pathologic score. In conclusion, the pathologic landmarks of this peculiar evolution of ischemic heart disease towards dilatation are 1) multiple noncontiguous scarred areas; 2) multivessel and multisegment coronary narrowings, with left anterior descending coronary artery most frequently involved; 3) spared myocardium likely in hibernating condition; and 4) compensatory hypertrophy of spared myocardium (inadequate to preserve ventricular function) documented by increased heart weight with nearly normal ventricular thickness and myocyte diameter.