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[Clinical findings with inhibitors of the renin-angiotensin system]
R Dietz1, T Süsselbeck, K J Osterziel
1Medizinische Universitätsklinik, Abteilung für Kardiologie, Pulmologie und Angiologie, Heidelberg.
Insights
Angiotensin converting enzyme (ACE) inhibitors improve heart failure by reducing cardiovascular resistance and enhancing blood supply. However, their effectiveness in preventing restenosis after coronary angioplasty in patients remains limited.
Area of Science:
- Cardiology
- Pharmacology
Context:
- Cardiovascular diseases are linked to heightened renin-angiotensin system activity.
- Severe heart failure patients exhibit increased sympathetic and decreased parasympathetic tone.
Purpose:
- To evaluate the impact of angiotensin converting enzyme (ACE) inhibitors on cardiovascular resistance and autonomic nervous system activity in heart failure patients.
- To assess the clinical efficacy of ACE inhibitors in preventing restenosis post-coronary angioplasty.
Summary:
- ACE inhibitors reduce systemic, renal, and cardiovascular resistance, improving cardiac blood supply and diminishing workload in heart failure.
- While ACE inhibitors show promise in animal models for preventing neo-intima proliferation, clinical trials have not demonstrated a significant reduction in restenosis rates in patients with coronary artery disease.
- ACE inhibitors can mitigate the increased sympathetic activity and vagal blockage associated with renin-angiotensin system activation in heart failure.
Impact:
- ACE inhibitors offer a therapeutic strategy for managing heart failure by improving hemodynamic parameters and autonomic balance.
- Further research is needed to clarify the role of ACE inhibitors in preventing adverse outcomes, such as restenosis, in specific cardiovascular interventions.
Abstract:
Cardiovascular diseases are often associated with increased activity of the systemic and/or local renin-angiotensin systems. Hence, with respect to the coronary vessels, it has been demonstrated that in patients with severe heart failure inhibition of the renin-angiotensin system with an angiotensin converting enzyme (ACE) inhibitor clearly reduces resistance in the systemic, renal and cardiovascular systems. This reduction in resistance improves the blood supply to the failing heart while, at the same time, diminishing the external workload. It is most likely this effect that contributes towards the improved progression of the underlying disease observed after ACE inhibitor administration. The clinical efficacy of ACE inhibitors in patients who had been subjected to repeated coronary angioplasty has, however, been disappointing. Although these agents exerted a clear inhibitory effect on neo-intima proliferation after balloon dilatation performed on animals, it was not observed in patients with coronary artery disease and did not prevent restenosis. In patients suffering from heart failure there is an increase in sympathetic tone and a decrease in parasympathetic tone. An increase in activity of the renin-angiotensin system produces an increase in sympathetic activity at the level of the peripheral sympathetic synapses and vagus blockage via its effect on the vagal centres in the postremal area. Both effects can be clearly diminished by administering ACE inhibitors. Although high sympathetic tone and low parasympathetic activity are indicators of low life expectancy in heart failure, a clear correlation between the incidence of sudden cardiac death and the changes in autonomic nervous system activity has not yet been established.(ABSTRACT TRUNCATED AT 250 WORDS)