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Combined sympathetic suppression and angiotensin-converting enzyme inhibition in congestive heart failure
A J Manolis1, C Olympios, M Sifaki
1Department of Cardiology, Tzanio Hospital, Piraeus, Greece.
Insights
Combining clonidine and captopril significantly improved hemodynamics in congestive heart failure (CHF) patients. This combination therapy effectively reduced preload and afterload, offering enhanced benefits over captopril alone for CHF management.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Neurohormonal activation is key in congestive heart failure (CHF) pathogenesis and prognosis.
- Angiotensin-converting enzyme (ACE) inhibition is standard, but sympathetic inhibition is a newer therapeutic approach for CHF.
Purpose of the Study:
- To evaluate the hemodynamic and hormonal effects of a combined clonidine and captopril therapy versus captopril alone in patients with Class III or IV CHF.
Main Methods:
- A single-blind, parallel study involving 16 CHF patients.
- Administered a single oral dose of clonidine 0.15 mg + captopril 6.25 mg or captopril 6.15 mg + placebo.
- Measured hemodynamic and hormonal parameters (e.g., RAP, PCWP, MPAP, SVR, SVI, plasma norepinephrine, plasma renin activity) at baseline and 2 hours post-treatment.
Main Results:
- The combination therapy significantly decreased preload parameters (RAP, PCWP, MPAP) compared to captopril alone.
- Both treatments reduced systemic vascular resistance (SVR), but the combination therapy led to a significantly greater increase in stroke volume index (SVI).
- Plasma norepinephrine was suppressed only with the combination therapy, while plasma renin activity increased with both regimens.
Conclusions:
- Combination therapy with clonidine and captopril offers significant improvements in preload and afterload parameters in CHF patients.
- This combination demonstrates additive hemodynamic and hormonal benefits, including correction of activated neurohormones, suggesting a promising therapeutic strategy for CHF.
Abstract:
Neurohormonal activation is a pathogenic contributor and prognostic marker in congestive heart failure (CHF). While angiotensin-converting enzyme (ACE) inhibition is now first-line therapy, sympathetic inhibition has only lately been proposed to this aim. Recently, we reported improvement of preload parameters by sympathetic suppression with clonidine. In the present paper we studied the effects of a single oral dose of clonidine 0.15 mg+captopril 6.25 mg combination, compared with captopril 6.15+placebo in a single-blind parallel study on 16 patients with Class III or IV CHF (13 males, 3 females, aged 62 +/- 8 years, with an ejection fraction of 33 +/- 8%). Hemodynamic and hormonal measurements were taken at baseline after a diagnostic cardiac catheterization and again 2 hours after treatment. The results indicate that preload parameters such as RAP, PCWP and MPAP decreased significantly with the combination therapy but not with captopril alone. On the contrary, SVR decreased significantly with both treatments and SVI increased significantly with both-but the latter change was significantly greater with the captopril/clonidine combination than with captopril alone. Suppression of plasma norepinephrine occurred with the combination only (evidently attributable to clonidine), whereas plasma renin activity increased with both regimens, due apparently to captopril. Our results indicate that the combination of clonidine with captopril induces significant improvements in both preload and afterload parameters of CHF and correction of activated neurohormones, suggesting additive hemodynamic and hormonal benefits from the two treatment modalities.