Anti-ischemic effects of angiotensin- converting enzyme inhibition in hypertension

Exaggerated vasopressor response to exercise and cerebral blood flow velocity

We studied 10 young adults, normotensive at rest, comprising a control group (n = 5) with normal blood pressure responsiveness to exercise and an experimental group exhibiting greater percentage of body fat and body mass index (BMI) than the controls, with exaggerated blood pressure (vasopressor) responsiveness to exercise (EEBPR) (n = 5). Lower absolute and varying oxygen consumption/body weight normalized units of middle cerebral arterial blood flow velocity (MCAV) were found during exercise in the experimental group (P < .01). These findings support the hypothesis that the combination of EEBPR and high BMI is associated with low MCAV that may put such individuals at risk for cerebral hypoperfusion and cognitive deficits.

Zofenopril in the treatment of patients with arterial hypertension and stable coronary heart disease: effects on oxidative stress and flowdependent vasodilatation

Aim. To compare the effects of ACE inhibitors zofenopril and perindopril on endothelial function and oxidative stress (OS) in patients with stable CHD and AH. Material and methods. In total, 40 patients with stable CHD (Functional Class II-III effort angina) and Stage 1-2 AH received zofenopril (7,5-30 mg/d; mean dose 18,6±8,8 mg/d; n=17) or perindopril (2-8 mg/d; mean dose 4,1±2,1 mg/d; n=23) for 12 weeks. At baseline and in the end of the study, all patients underwent reactive hyperemia test (RHT), to assess flow-dependent vasodilatation of brachial artery, and the measurement of OS parameters (malone dialdehyde, MDA, in low-density lipoproteins, MDALDL) and antioxidant parameters (superoxide dismutase (SOD) and glutathione peroxidase (GPO) activity in erythrocytes).

Results. In both groups, a similar reduction in systolic and diastolic blood pressure levels was observed. In the zofenopril group, a significant elevation in brachial artery diameter increase during RHT, a significant increase in GPO activity, and some reduction in MDALDL levels were observed, which points to antioxidant system (AOS) activation and OS reduction. No similar changes of these parameters were observed in the perindopril group. Conclusion. In patients with stable CHD and AH, zofenopril, but not perindopril, reduced OS severity and increased AOS system activity, which was associated with improved endothelial-dependent vasodilatation.

Cardiac Medical Therapy among Patients Undergoing Abdominal Aortic Aneurysm Repair

Open abdominal aortic aneurysm (AAA) repair is a common surgical procedure associated with high mortality rates. Our objective was to describe the use of in-hospital cardiac medical therapy among patients undergoing open AAA repair and to examine the effect of perioperative cardiac medical therapy on in-hospital mortality. We examined clinical data and in-hospital medication use among 223 patients who underwent open AAA repair at three North American hospitals, all of which used the Transition resource and cost accounting system. Medication use was described [angiotensin converting enzyme (ACE) inhibitors, aspirin, ss-blockers, and statins] within the cohort at five specific periods of time: presurgery, day of surgery, 1 day after surgery, postsurgery, and discharge. We then performed a matched case-control study where cases were defined as patients who died in-hospital. We compared medication use between cases and controls to assess its impact on in-hospital mortality. Most patients were elderly (mean age 72.5 +/- 9.8 years), 70.4% were male, and in-hospital mortality within the cohort was 10.8%. Medication use in all periods of administration was low. ss-Blocker use was highest among all classes on the day of surgery, with 20.6% of patients undergoing AAA repair receiving the medication. Less than 50% of patients received any of the medications at discharge. After adjusting for baseline differences, perioperative ACE inhibitor use showed a trend toward a protective effect [odds ratio (OR) = 0.09, 95% confidence interval (CI) 0.01-1.31, p = 0.08], and perioperative ss-blocker use was significantly associated with a decrease in mortality (OR = 0.07, 95% CI 0.01-0.87, p = 0.04). Cardiac medical therapy among patients undergoing AAA repair is low throughout all periods of hospitalization. ACE inhibitor and ss-blocker use may be associated with decreased in-hospital mortality.

Abnormal coronary microvascular endothelial function in humans with asymptomatic left ventricular dysfunction

BACKGROUND

Coronary endothelial dysfunction may potentially lead to myocardial ischemia and to the progression of heart failure. Though endothelial dysfunction is associated with advanced heart failure in humans, relatively little is known regarding their temporal relationship. Thus, the current study was designed to test the hypothesis that coronary endothelial dysfunction is present in patients with asymptomatic left ventricular dysfunction.

METHODS AND RESULTS

Three hundred patients without symptoms of heart failure, with normal or mildly diseased coronary arteries at angiography underwent coronary vascular reactivity evaluation using intracoronary adenosine, acetylcholine (ACH) and nitroglycerin. Patients were divided into 2 groups based on the left ventricular ejection fraction (EF): patients with asymptomatic left ventricular dysfunction (ALVD), EF <45% (n = 11); and patients with EF > or =45% (n = 289, controls). Except for a lower high-density lipoprotein level in patients with ALVD, there were no significant differences between the groups in regards to conventional cardiovascular risk factors. There was no difference in the change (mean +/- SE) in epicardial diameter in response to ACH (-21.7% +/- 7.2% vs -13.8% +/- 1.5%, P =.3). The change in coronary blood flow in response to ACH was significantly attenuated in the patients with ALVD when compared to the controls (-18.5% +/- 14.9% vs 74.0% +/- 7.2%, P <.013). By multivariate analysis, EF was an independent predictor of coronary microvascular dilation with ACH (P <.001).

CONCLUSION

The current study demonstrates that coronary microvascular endothelial dysfunction is present in ALVD. Thus, coronary endothelial dysfunction may be an early event in the pathophysiology of heart failure.

Endothelial dysfunction: a marker of atherosclerotic risk

Endothelial dysfunction is a systemic disorder and a key variable in the pathogenesis of atherosclerosis and its complications. Current evidence suggests that endothelial status is not determined solely by the individual risk factor burden but rather, may be regarded as an integrated index of all atherogenic and atheroprotective factors present in an individual, including known as well as yet-unknown variables and genetic predisposition. Endothelial dysfunction reflects a vascular phenotype prone to atherogenesis and may therefore serve as a marker of the inherent atherosclerotic risk in an individual. In line with this hypothesis, dysfunction of either the coronary or peripheral vascular endothelium was shown to constitute an independent predictor of cardiovascular events, providing valuable prognostic information additional to that derived from conventional risk factor assessment. Interventions like risk factor modification and treatment with various drugs, including statins and angiotensin-converting enzyme inhibitors, may improve endothelial function and thereby, potentially prognosis. Hence, given its reversibility and granted the availability of a diagnostic tool to identify patients at risk and to control the efficacy of therapy in clinical practice, endothelial dysfunction may be an attractive primary target in the effort to optimize individualized therapeutic strategies to reduce cardiovascular morbidity and mortality.