[Tolerance of beta blockader treatment in dilated cardiomyopathy]

Abstract

We studied 78 consecutive patients with dilatative cardiomyopathy who were in our hospital because of heart failure. We wanted to evaluate which parameters could be useful in identifying patients who could be treated with betablockers. All patients were hemodynamically well balanced. They were treated with effective dosage of digoxin and diuretics. We evaluated the following hemodynamic parameters: heart rate, mean arterial pressure, mean pulmonary arterial pressure (MPAP), right atrial pressure, pulmonary wedge pressure, cardiac output, cardiac index, systemic vascular resistance, pulmonary vascular resistance, and also the neurohumoral parameters: VO2, max exercise duration, plasmatic norepinephrine levels (NE) and plasmatic renin activity (PRA). Then all patients were treated with atenolol 25 mg/die followed by 50 mg/die. In the overall population, 37 patients well tolerated the therapy with betablocker (Group A); 41 patients did not tolerate the therapy (Group B). Between the 2 groups we only found a significant difference in MPAP 31 +/- 20 vs 51 +/- 31 mmHg (p = 0.02), NE 781 +/- 467 vs 1551 +/- 1249 pg/ml (p = 0.01), PRA 1.8 +/- 2.9 vs 5.6 +/- 4.5 ng/ml/h (p = 0.02). On the basis of our results we hypothesize that patients with high neurohumoral activation do not tolerate betablocker treatment.