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Long-term control of congestive heart failure with captopril
Insights
Captopril therapy gradually improves resistant congestive heart failure by reducing peripheral resistance and pulmonary congestion. The aldosterone/renin ratio effectively indicates patient compliance with this angiotensin-converting enzyme inhibitor treatment.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Resistant congestive heart failure (CHF) poses significant therapeutic challenges.
- Angiotensin-converting enzyme (ACE) inhibitors like captopril are crucial in managing CHF.
- Understanding the long-term hemodynamic effects of captopril is essential for optimizing treatment.
Purpose of the Study:
- To assess the long-term hemodynamic effects of captopril in patients with resistant congestive heart failure.
- To identify hemodynamic markers predicting response to captopril therapy.
- To evaluate the relationship between hormonal changes and clinical response.
Main Methods:
- Sequential hemodynamic studies over six months in 19 patients with resistant CHF.
- Measurement of cardiac output, stroke volume, heart rate, total peripheral resistance, and pulmonary mean transit time.
- Analysis of plasma renin activity and aldosterone levels.
Main Results:
- Gradual hemodynamic improvement observed in most patients over three months.
- Significant reductions in total peripheral resistance and cardiopulmonary volume correlated with clinical improvement.
- Shortening of pulmonary mean transit time was a consistent indicator of response.
- Increased plasma renin activity and decreased plasma aldosterone were noted, with the aldosterone/renin ratio indicating compliance.
Conclusions:
- Captopril therapy can lead to gradual but significant improvement in resistant CHF.
- Peripheral hemodynamic changes, including reduced total peripheral resistance and cardiopulmonary volume, are key to captopril's efficacy.
- The plasma aldosterone/renin activity ratio serves as a reliable marker for patient adherence to captopril treatment.
Abstract:
The long-term effects of captopril therapy were assessed by sequential hemodynamic studies over a 6 month period in 19 patients with resistant congestive heart failure. Initial improvement during the first week of therapy was noted only in 11 and was marked by significant (p less than 0.005) increases in cardiac output and stroke volume, slowing of heart rate, and reduction of total peripheral resistance. Of the remaining eight patients, seven improved subsequently with maintained therapy so that by the end of 3 months of treatment only one patient failed to respond significantly. The hemodynamic index that reflected response most consistently was the shortening in pulmonary mean transit time. Simultaneously with clinical improvement there was a reduction in cardiopulmonary volume that reflected a reduction in pulmonary congestion and probably systemic vasodilation. Associated with these hemodynamic changes there was an increase in plasma renin activity and a significant reduction in plasma aldosterone, but these changes did not differ significantly between patients who responded markedly and those who responded moderately to converting enzyme inhibition. These results suggest that the response of congestive heart failure to captopril can occur gradually. Improvement was related to peripheral hemodynamic changes which led to a reduction in both total peripheral resistance and cardiopulmonary volume. The reduction in the plasma aldosterone/renin activity ratio was an effective marker of compliance.