enalaprilat-anhydrous and Angina-Pectoris

Topics: Angina Pectoris; Angiotensin-Converting Enzyme Inhibitors; Captopril; Coronary Disease; Enalaprilat; Hemodynamics; Humans; Hypertension; Myocardial Infarction

We tested the hypothesis that enalaprilat induces preconditioning (PC)-mimetic actions in patients with stable coronary artery disease.. Angiotensin-converting enzyme (ACE) inhibitors increase the bioavailability of bradykinin, which induces cardiac PC.. Twenty-two patients undergoing coronary angioplasty were randomized to an intracoronary infusion of enalaprilat or placebo, followed 10 min later by a PC protocol.. In control patients, the ST-segment shift was greater during the first inflation than during the second and third inflations, both on the intracoronary electrocardiogram (ECG) (21.0 +/- 2.8 mm vs. 13.0 +/- 2.0 mm and 13.0 +/- 2.0 mm, p < 0.05) and the surface ECG (16.0 +/- 4.0 mm vs. 10.0 +/- 2.0 mm and 9.0 +/- 2.0 mm, p < 0.05). In contrast, enalaprilat-pretreated patients showed no change in ST-segment shift during inflations on either the intracoronary or the surface ECG. During the first inflation, the ST-segment shift was significantly smaller in treated versus control patients. The chest pain score during the first inflation was also significantly smaller in treated patients versus control patients (33.0 +/- 6.0 mm vs. 64.0 +/- 6.0 mm) and did not change in treated patients during the second and third inflations, whereas it decreased significantly in control patients. In a subset of 6 patients, enalaprilat increased coronary blood flow during infusion, but this effect dissipated before the beginning of angioplasty.. Pretreatment with enalaprilat attenuates the manifestations of myocardial ischemia during angioplasty. This is the first in vivo evidence showing that an ACE inhibitor protects human myocardium, possibly via PC-mimetics actions, a novel property that might explain the cardioprotective actions of these drugs.

Topics: Angina Pectoris; Angioplasty, Balloon, Coronary; Angiotensin-Converting Enzyme Inhibitors; Chi-Square Distribution; Chronic Disease; Coronary Angiography; Coronary Circulation; Electrocardiography; Enalaprilat; Female; Follow-Up Studies; Humans; Infusions, Intralesional; Ischemic Preconditioning, Myocardial; Male; Middle Aged; Probability; Reference Values; Risk Assessment; Severity of Illness Index; Treatment Outcome; Vascular Patency

There is little information on the processes affecting selective tissue ACE inhibition and the implications in human subjects. We compared intravenously administered ACE inhibitors, perindoprilat and enalaprilat, for myocardial drug uptake and effects on angiotensin and bradykinin peptides versus hemodynamic effects in 25 patients with stable angina and well-preserved left ventricular systolic function. Myocardial uptake was rapid and more efficient for perindoprilat than for enalaprilat (peak content at 26+/-3 and 30+/-4 seconds, 0.58+/-0.12% and 0.27+/-0.07% of the administered dose for perindoprilat and enalaprilat, respectively, P=0.04 for difference). Both drugs caused a decrease in angiotensin (Ang) II level, an increase in Ang I level, and reduction in Ang II/Ang I ratio in arterial and coronary sinus blood. Bradykinin (BK)-(1-9) and BK-(1-8) levels increased in arterial blood and BK-(1-8) levels increased in coronary sinus blood after drug administration. Perindoprilat and enalaprilat caused a small decrease in mean arterial pressure (-3+/-1%, P<0.05; and -4+/-1%, P<0.01, respectively) and LV+dP/dt (-5.8+/-1.7%, P<0.01 and -4.2+/-2.8%, P<0.05, respectively), whereas systemic vascular resistance index was unchanged. Despite relatively cardioselective uptake of perindoprilat, both drugs had similar effects on the cardiac metabolism of angiotensin and bradykinin and on cardiac function. Under resting conditions, both drugs exerted small negative inotropic effects.

Topics: Adult; Aged; Angina Pectoris; Angiotensin-Converting Enzyme Inhibitors; Angiotensins; Blood Pressure; Bradykinin; Electrocardiography; Enalaprilat; Female; Hemodynamics; Humans; Indoles; Injections, Intravenous; Kinetics; Male; Middle Aged; Myocardium

We sought to demonstrate non-angiotensin converting enzyme (ACE) dependent angiotensin II (AII) generating pathways in resistance arteries from patients with chronic heart failure (CHF).. Non-ACE dependent AII generation occurs in resistance arteries from normal volunteers. Inhibition of non-ACE dependent AII generation may have therapeutic potential in CHF.. Resistance arteries were dissected from gluteal biopsies from patients with coronary heart disease (CHD) and preserved left ventricular function and from patients with CHF. Using wire myography, concentration response curves to angiotensin I (AI) and AII were constructed in the presence of 1) vehicle, 2) chymostatin [an inhibitor of chymase], 3) enalaprilat, and 4) the combination of chymostatin and enalaprilat.. In resistance arteries from patients with CHD, the vasoconstrictor response to AI was not inhibited by either inhibitor alone (chymostatin [p > or = 0.05] or enalaprilat [p > or = 0.05]) but was significantly inhibited by the combination (p < 0.001). In arteries from patients with CHF, AI responses were inhibited by enalaprilat (p < 0.05) but not by chymostatin alone (p > 0.05). The combination ofchymostatin and enalaprilat markedly inhibited the response to AI (p < 0.001) to a greater degree than enalaprilat alone (p < or = 0.01).. Non-ACE dependent AII generating pathways exist in resistance arteries from patients with both CHF and CHD. In resistance arteries from patients with CHD, inhibition of either the ACE or chymase pathway alone has no effect on AII generation, and both pathways must be blocked before the vasoconstrictor action of AI is inhibited. In CHF, blockade of ACE results in marked inhibition of responses to AI, but this is enhanced by coinhibition of chymase. These studies suggest that full suppression of the renin-angiotensin system cannot be achieved by ACE inhibition alone and provide a rationale for developing future therapeutic strategies.

Topics: Acetylcholine; Aged; Angina Pectoris; Angiotensin I; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Arteries; Bradykinin; Chymases; Enalaprilat; Female; Heart Failure; Humans; In Vitro Techniques; Losartan; Male; Middle Aged; Oligopeptides; Peptidyl-Dipeptidase A; Serine Endopeptidases; Vascular Resistance; Vasoconstriction

The pump function during exercise can be disturbed not only in hypertensives with coronary artery disease (CAD), but also in those with a normal angiogram.. In 10 hypertensive patients (group 1; aged 52+/-4 years, 1 men, 9 women) with ST segment depression during exercise and concomitant angina pectoris but normal coronary angiograms (microangiopathy) and without left ventricular hypertrophy (LVMI <110 g/m2), the left ventricular function at rest and during exercise was studied by cardiac catheterization and compared with 10 hypertensives with CAD (group 2; aged 57.6+/-4 years, 7 men, 3 women) and 10 hypertensives without ST segment depression (group 3; aged 51.8+/-5 years, 10 men) before and after intravenous administration of 1.25 mg enalaprilat.. The pulmonary capillary wedge pressure (PCWP) was normal at rest and pathologically increased at 60+/-13 W only in groups 1 and 2 (27.2+/-3 and 32.2+/-8 mm Hg, respectively), but not in group 3 (12.2+/-4 mm Hg; p<0.001). At the identical load level, the PCWP in patients with microangiopathy (group 1) was significantly (p<0.01) reduced after enalaprilat (-21.7%) and even normalized in 5 of 10 patients. This was accompanied by a significant (p>0.01) decrease in ST segment depression (-73.9%) and in the occurrence of angina pectoris, despite the fact that the rate-pressure product as a measure of myocardial oxygen consumption was significantly (p<0.05) increased. Also in patients with CAD enalaprilat had a significant effect on PCWP (p<0.01), ST segment depression (p<0.01), occurrence of angina pectoris (p<0.001), cardiac index (p<0.05), and stroke index (p<0.05) during exercise. In group 3 there were no significant changes in PCWP, cardiac index, and stroke index after enalaprilat either at rest or during exercise.. The functional improvement under the action of enalaprilat suggests that the advantages of the drug may be mediated mainly through an increase in myocardial blood flow and that angiotensin II might be involved in the restricted increase in coronary blood flow during dynamic exercise in hypertensives with coronary microangiopathy.

Topics: Angina Pectoris; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Coronary Disease; Enalaprilat; Exercise Test; Female; Hemodynamics; Humans; Hypertension; Male; Microcirculation; Middle Aged; Ventricular Dysfunction, Left