Search

In 72 patients with dilated cardiomyopathy the degree of morphological alterations were studied by transvenous endomyocardial biopsy. These findings were correlated to the clinical status, left ventricular ejection fraction, and to the catecholamine concentrations in plasma and myocardium. Muscle fiber diameter was negatively correlated to ejection fraction (r = -0.3, p = 0.02) and to the volume fraction of mitochondria (r = -0.32, p = 0.001). Between plasma norepinephrine concentration and ejection fraction a significant negative correlation was found (r = -0.37, p = 0.001). In contrast, myocardial norepinephrine concentration was positively correlated to ejection fraction (r = 0.25, p = 0.04). Between myocardial norepinephrine concentration and muscle fiber diameter a negative correlation was found (r = -0.46, p = 0.004). Patients with an EF of less than 30% and an EF of greater than 45% could be differentiated with an accuracy of 79%, when muscle fiber diameter, plasma norepinephrine concentration, and the density of capillary vessels were entered into a multi-variant analysis. In conclusion, dilated cardiomyopathy is associated with morphological alterations and alterations in plasma and myocardial catecholamine concentrations. Patients with highly reduced ventricular function could be best identified by the combined assessment of plasma catecholamine concentration, muscle fiber diameter, and density of capillary vessels.

To evaluate the prognosis of patients with idiopathic dilated cardiomyopathy (EF less than 50%) in 55 patients the myocardial catecholamine concentration, plasma catecholamine concentration, and left ventricular ejection fraction were determined. The follow-up time ranged from 7 to 47 months. At the time of follow-up 10 of the 55 patients (group A) had died and three had undergone hearttransplantation. Group A patients had a significant lower EF (27 +/- 10 vs 36 +/- 9%, p less than 0.03), a lower myocardial norepinephrine (254 +/- 168 vs 579 +/- 416 pg/mg, p less than 0.007), higher plasma norepinephrine (640 +/- 333 vs 372 +/- 254 pg/ml, p less than 0.008) and plasma epinephrine (391 +/- 340 vs 116 +/- 81 pg/ml, p less than 0.006) in comparison to patients, who were still alive and not transplanted (group B). Survival was significantly lower in patients with an EF less than 30%, a plasma norepinephrine concentration greater than 350 pg/ml, a plasma epinephrine concentration greater than 125 pg/ml, and a myocardial norepinephrine content less than 400 pg/mg. Cox regression analysis revealed that the ratio of plasma vs myocardial norepinephrine was the best prognostic indicator for patients with an EF less than 30% and this ratio plus the plasma norepinephrine concentration were the best prognostic indicators for the whole group of patients. These data suggest that myocardial norepinephrine content is an important prognostic factor in patients with idiopathic dilated cardiomyopathy.