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Risk factors and the effects of xamoterol in idiopathic dilated cardiomyopathy
K Watanabe1, Y Hirokawa, K Suzuki
1Division of Cardiology, Tsubame Rosai Hospital, Niigata.
Insights
Idiopathic dilated cardiomyopathy (DCM) survival is predicted by left ventricular size, cell diameter, and ventricular tachycardia. Xamoterol treatment improved hemodynamics and symptoms in DCM patients.
Area of Science:
- Cardiology
- Internal Medicine
Background:
- Idiopathic dilated cardiomyopathy (DCM) is a serious condition affecting heart muscle.
- Long-term survival rates and prognostic factors in DCM require further investigation.
Purpose of the Study:
- To identify predictors of survival in patients with idiopathic DCM.
- To evaluate the effects of xamoterol, a beta 1-partial agonist, on DCM patients.
Main Methods:
- A long-term follow-up study of 110 DCM patients.
- A prospective study of 26 DCM patients treated with xamoterol (200 mg daily).
- Analysis of survival rates, hemodynamic parameters, and exercise capacity.
Main Results:
- Key predictors for 3-year survival included left ventricular end-diastolic volume index (LVEDVI), myocardial cell diameter, and sustained ventricular tachycardia (VT).
- Xamoterol therapy led to improvements in cardiothoracic ratio, left ventricular dimensions, exercise heart rate, duration, fractional shortening, and ejection fraction.
- The 3-year survival rate in the xamoterol group was 83%.
Conclusions:
- LVEDVI, myocardial cell diameter, and VT occurrence are significant prognostic factors in DCM.
- Adjunctive xamoterol therapy demonstrates beneficial effects on hemodynamics and symptoms in DCM patients.
Abstract:
A long-term follow-up study was performed for 110 patients with idiopathic dilated cardiomyopathy (DCM) for 34 +/- 12 months (range 3-122 months). Thirteen patients died of heart failure, 15 of sudden death and one of non-cardiac death. The 3- and 5-year survival rates were 78 and 62%, respectively. The important factors in predicting the 3-year survival rate were left ventricular end-diastolic volume index (LVEDVI > or = 150 ml/m2 = 66%, < 150 ml/m2 = 93%, p < 0.01), myocardial cell diameter (> 25 microns = 42%, < or = 25 microns = 87%, p < 0.05) and sustained ventricular tachycardia (VT present = 32%, absent = 85%, p < 0.01). In a prospective study, 26 patients with DCM were given a beta 1-partial agonist, xamoterol (200 mg daily) and were followed for 35 +/- 15 months (6-53 months). The cardiothoracic ratio, left ventricular end-diastolic dimension and exercise heart rate decreased, and the exercise duration, fractional shortening and ejection fraction increased after xamoterol therapy. The 3-year survival rate was 83%. These results suggest that the important factors in predicting the survival rate of DCM patients were LVEDVI, myocardial cell diameter and the occurrence of VT. Adjunctive xamoterol therapy in DCM had a beneficial effect on hemodynamics and symptoms.