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Determinants of acute and long-term response to converting enzyme inhibitors in congestive heart failure
Insights
Converting enzyme inhibitors (CEIs) like captopril significantly improve hemodynamics and reduce symptoms in patients with congestive heart failure (CHF). Long-term use enhances exercise capacity, offering effective vasodilator therapy for advanced cardiac dysfunction.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Congestive heart failure (CHF) involves impaired cardiac function and neurohumoral activation.
- Converting enzyme inhibitors (CEIs) are a class of drugs used to manage hypertension and heart failure.
Purpose of the Study:
- To evaluate the acute hemodynamic and neurohumoral effects of CEIs (captopril and teprotide) in patients with moderate-to-severe CHF.
- To assess the long-term efficacy of captopril therapy in improving symptoms and exercise tolerance in CHF patients.
Main Methods:
- Acute hemodynamic and neurohumoral responses to captopril and teprotide were measured in 42 CHF patients.
- Plasma renin activity (PRA) and plasma norepinephrine (PNE) were analyzed.
- Long-term captopril therapy was administered to 12 patients, with exercise tolerance assessed.
Main Results:
- CEIs acutely decreased pulmonary artery pressure, capillary wedge pressure, mean arterial pressure, systemic vascular resistance, pulmonary vascular resistance, and heart rate.
- Cardiac index significantly increased post-CEI administration.
- Elevated baseline PRA correlated with greater hemodynamic improvements.
- Long-term captopril therapy led to symptomatic improvement and increased exercise duration.
Conclusions:
- CEIs induce beneficial acute hemodynamic changes in patients with CHF, improving left ventricular function.
- Captopril provides effective, well-tolerated long-term vasodilator therapy for advanced cardiac dysfunction.
- CEI treatment significantly reduces CHF symptoms and enhances exercise capacity.
Abstract:
In 42 patients with moderate-to-severe congestive heart failure (CHF), the acute hemodynamic and neurohumoral response to the converting enzyme inhibitors (CEIs) captopril (CPT) and teprotide were measured. Plasma renin activity (PRA) was elevated and correlated with control plasma norepinephrine (PNE) but not with any of the control hemodynamics. Acutely after CEIs, significant (p less than 0.001) decreases in right atrial pressure, pulmonary artery pressure (PAP), capillary wedge pressure (PCWP), mean arterial pressure (MAP), total systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), and heart rate (HR, p less than 0.002), as well as an increase in cardiac index (p less than 0.001), were observed. Control PRA correlated with the degree of hemodynamic change for PAP (r = -0.64), PCWP (r = -0.66), SVR (r = -0.61), and PVR (r = -0.61). Long-term CPT therapy in 12 of these patients resulted in symptomatic improvement and a marked increase in exercise tolerance (7.4 to 10.4 minutes, p less than 0.009). These data suggest that CEIs effect beneficial acute hemodynamic improvements in depressed left ventricular function, leading to substantial reduction in disabling symptomatology and augmentation of exercise capacity in patients with stable severe CHF. Thus, CPT appears to provide well-tolerated, effective long-term ambulatory vasodilator therapy for advanced cardiac dysfunction.