Effects of early angiotensin-converting enzyme inhibition in patients with non-ST-elevation acute anterior myocardial infarction

BACKGROUND

No data are available on the clinical efficacy of the early administration (<24 hours from onset of chest pain) of angiotensin-converting enzyme inhibitors in non-thrombolysed patients with non-ST-elevation myocardial infarction (NSTEMI). We have addressed this issue in a subgroup of NSTEMI patients enrolled in the SMILE trial.

METHODS

Of the overall population of 1556 patients, 526 (33.8%) had an anterior wall NSTEMI, defined as an ST elevation <1 mm or an ST depression in at least two contiguous precordial leads with or without new abnormal Q waves. No patient of the SMILE Study received thrombolytic therapy or was reperfused. Patients were randomized, double-blind, to zofenopril (n = 253) or placebo (n = 273) for 6 weeks. The primary end point was the effect of treatment on the 6-week combined occurrence of death and severe congestive heart failure (CHF). Secondary end points included the evaluation of the 6-week rate of severe CHF as well as the 1-year mortality rate.

RESULTS

After 6 weeks of treatment, zofenopril significantly reduced both the incidence of the primary end point (risk reduction 65%, 95% CI 20-80, 2P = .003) and the 6-week incidence of severe CHF (84%, 95% CI 33-97, 2P = .006) in NSTEMI patients. One-year mortality was also significantly reduced by zofenopril treatment (43%, 95% CI 14-57, 2P = .036).

CONCLUSIONS

Results of this post hoc analysis of the SMILE Study strongly suggest the benefit of the early administration of zofenopril even in patients with an anterior wall NSTEMI.

A review of the angiotensin-converting enzyme inhibitor, zofenopril, in the treatment of cardiovascular diseases

Based on preclinical and clinical findings, zofenopril appears to be an angiotensin-converting enzyme (ACE) inhibitor with high potency, significant tissue selectivity and a long duration of action. Its ancillary properties, such as antioxidant activity and cardiovascular (CV) protection, make this drug potentially suitable for the treatment, and possibly prevention, of several CV diseases. There is a large body of evidence that support a complex interaction between ACE inhibitors and CV disease. A review of the preclinical profile of zofenopril clearly suggest that such interaction can be even more complex and could involve some drug-specific properties directly involved in the definition of the overall clinical profile of zofenopril as emerged from randomised clinical trials. In particular, zofenopril combines the feature of an effective ACE inhibitor, with plasma and tissue activity, along with that of an antioxidant compound, and both these characteristics can contribute to its capacity of controlling hypertension and improving the prognosis of patients with coronary artery disease. The results of The Survival of Myocardial Infarction Long term Evaluation (SMILE) trials have demonstrated that the early administration of zofenopril to patients with acute myocardial infarction is associated with a significant reduction in the 6-week occurrence of major CV events (death and congestive heart failure) in high-risk patients with anterior non-thrombolysed myocardial infarction, and this effect is enhanced in some higher-risk subgroups of patients, such as those with a history of diabetes or arterial hypertension.

Serum cholesterol levels, blood pressure response to stress and incidence of stable hypertension in young subjects with high normal blood pressure

RATIONALE

Elevated serum cholesterol levels are common in patients with high blood pressure (BP) and could contribute to the progression of the hypertensive disease.

OBJECTIVE

To determine whether serum cholesterol levels affect the BP response to mental stress (MA) and the development of stable hypertension in young subjects with high normal BP.

METHODS

Seventy young (age < 45 years) high normal BP subjects with elevated (> 200 mg/dl, n = 49; HC) or normal (< or = 199 mg/dl, n = 21; NC) serum cholesterol levels, and 20 normotensive normocholesterolaemic (serum cholesterol < 199 mg/dl; C) subjects undergoing standardized mental challenge (mental arithmetic) were followed up for 15 years according to a prospective, longitudinal, cohort study design conducted in an ambulatory setting. The main outcome measure was the evaluation of the 15-year incidence of stable hypertension (diastolic BP > 95 mmHg).

RESULTS

After adjustment for age, resting BP, family history of high BP and body mass index at the study entry, high normal BP subjects with HC showed an enhanced BP reactivity to stress and a higher 15-year incidence of stable hypertension compared to high normal BP and NC subjects [relative risk (RR) = 2.1; 95% confidence interval (CI) = 1.7-5.5, P < 0.001] and controls (RR = 3.1; 95% CI = 1.4-5.3, P < 0.001). In a multivariate analysis of data the presence of high cholesterol levels was an independent predictor for the development of hypertension.

CONCLUSION

These data suggest that subjects with high normal BP and elevated serum cholesterol might have an exaggerated cardiovascular response to stress and have an increased risk for stable hypertension that can be detected at young age.

Effects of the early ACE inhibition in diabetic nonthrombolyzed patients with anterior acute myocardial infarction

OBJECTIVE

The aim of the present study was to evaluate the clinical efficacy of the ACE inhibitor zofenopril in a cohort of diabetic patients with nonthrombolyzed anterior acute myocardial infarction who were enrolled in the Survival of Myocardial Infarction Long-Term Evaluation (SMILE) trial.

RESEARCH DESIGN AND METHODS

Among the overall population of 1,512 patients, 303 (20.0%) had diabetes. The primary end point of this study was the effect of treatment on the 6-week combined occurrence of death and severe congestive heart failure (CHF). Secondary end points included the evaluation of the 6-week rate of major cardiovascular events as well as the 1-year survival rate.

RESULTS

After 6 weeks of double-blind treatment, zofenopril significantly reduced both the incidence of the primary end point (8.6 vs. 18.3%; P = 0.019) and the 6-week incidence of severe CHF (0 vs. 7.3%; P = 0.001) in diabetic patients, and the effect was greater than that observed in nondiabetic patients. Conversely, 1-year mortality was significantly reduced among nondiabetic patients (9.1 vs. 13.8%; P = 0.010), whereas in the diabetic population, the decrease did not reach statistical significance (13.7 vs. 16.5%; P = 0.52).

CONCLUSIONS

The present data suggest that the clinical outcome of patients with diabetes and myocardial infarction can be significantly improved by early treatment with zofenopril. The lesser effect on 1-year mortality seems to suggest that long-term treatment is probably needed to maintain the benefits of the early ACE inhibition in patients with diabetes.

Fixed combinations of delapril plus indapamide vs fosinopril plus hydrochlorothiazide in mild to moderate essential hypertension

This 12-week randomized, parallel-group, multicenter study compared fixed combinations of delapril (D) 30 mg plus indapamide (I) 2.5 mg and fosinopril (F) 20 mg plus hydrochlorothiazide (H) 12.5 mg in 171 adult patients with mild to moderate essential hypertension. After a 2-week placebo run-in, sitting and standing systolic (SBP) and diastolic blood pressure (DBP) was measured by conventional sphygmomanometry. The primary efficacy endpoint was the percentage of normalized (sitting DBP < or =90 mm Hg) and responder (sitting DBP reduction of 10 mm Hg or DBP < or =90 mm Hg) patients. Treatment effects were analyzed in the intention-to-treat (ITT; n = 171) and the per-protocol (PP; n = 167) populations. The percentage of normalized and responder patients did not differ significantly between the D + I (87.4% and 92%) and the F + H (81% and 86.9%) ITT groups. Similar results were seen in the PP population. In ITT and PP patients, sitting and standing SBP and DBP values were comparable at baseline in the two groups and were significantly (P<.01) and similarly reduced at weeks 4, 8, and 12. Neither treatment induced reflex tachycardia, and both regimens were well tolerated. Four patients in the F + H group dropped out because of adverse events. In this study, the efficacy and safety of D + I were comparable to those of F + H in patients with mild to moderate essential hypertension.

Beta-blockade in hypertension and congestive heart failure

Hypertension is common and increases the risk of death from coronary artery disease and cerebral vascular disease. The reason for treating hypertension is to prevent the long-term complications of this disorder. Many studies of antihypertensive therapy have produced only modest reductions in coronary events; in particular, with the use of beta-blockers. Clinical trials and meta-analyses have shown a lesser effect of these drugs on primary prevention of coronary events, cardiovascular and total mortality with respect to other antihypertensive approaches based on the use of low-dose diuretic therapy, especially in the elderly, even if the reduction of stroke and heart failure (HF) were similar. New beta-blockers with vasodilating properties due to the capacity to enhance the release of endothelial nitric oxide, then lessening a contributory mechanism to the pathogenesis of atherosclerosis as endothelial damage and dysfunction, seem to possess considerable potential in the treatment of hypertension, particularly in terms of improvement of cardiovascular outcome of patients. In HF, there is now considerable interest in the therapeutic use of beta-blockade. Some recent clinical trials have demonstrated conclusive evidence of the beneficial effects of beta-blocker therapy on survival in chronic HF. As a result of these data, beta-blocker therapy has become part of standard therapy for patients with chronic HF, in addition to angiotensin-converting enzyme-inhibitors and diuretics. The treatment is, in general, well tolerated. There are, however, some unanswered questions. One is whether some beta-blockers may be better than others. The major mortality benefit is probably a class-effect of beta1-adrenoceptor blockade, but the differences between beta-blockers might be clinically relevant. For example, it is under debate whether ancillary properties of some beta-blockers, such as the capability of exerting antioxidant effects or enhancing the nitric oxide production, may contribute to the clinical effects of these drugs. Future clinical trials will report over the next few years and help to answer the question about differences in mortality effects among types of beta-blocking agents, thus correctly defining the precise role of these drugs in the wide spectrum of cardiovascular disease.

Anti-ischemic effects of angiotensin-converting enzyme inhibitors: a future therapeutic perspective

The renin-angiotensin system and angiotensin-converting enzyme (ACE) are increasingly being implicated in the pathogenesis of coronary artery disease and its sequelae and the potential of ACE inhibitors to protect the heart is a topic that has emerged recently as a matter for scientific discussion. Experimental and clinical studies have shown the beneficial effects of ACE inhibitors on the metabolism, function and structure of healthy and damaged hearts and these data support the concept of both primary and secondary cardioprotection with this class of drugs. Animal studies have demonstrated the potential beneficial effects of ACE inhibition at a variety of sites, including improvement of endothelial function, inhibition of platelet aggregation, prevention of atherosclerotic lesions and inhibition of myointimal proliferation, extending the concept to a more general definition of cardiovascular protection with ACE inhibitors involving both the heart and the vessels. ACE inhibitors prevent stimulation of smooth muscle cell angiotensin-II (A-II) receptors, thereby blocking both contractile and proliferative actions of A-II. In addition, ACE inhibition of kininase inhibits the breakdown of bradykinin, a direct stimulant of nitric oxide release from the intact endothelial cell. Thus, at the cellular level ACE inhibition shifts the balance of ongoing mechanisms in favour of those promoting vasodilatory, anti-aggregatory, antithrombotic and antiproliferative effects. Although these data have not all been validated in human studies, the reduction of ischemic events in studies of ACE inhibition in left ventricular dysfunction (LVD) and, more recently, also in patients without LVD, cannot be explained solely by improved hemodynamics, and it is possible that actions on the endothelium, the atherosclerotic process and platelets are at least in part responsible. So, the available data underlie the potential benefits of ACE inhibition in the field of ischemic heart disease and atherosclerosis; the results of ongoing studies in humans looking more directly at the influence of ACE inhibitors in this setting are awaited with interest.

Use of statins and blood pressure control in treated hypertensive patients with hypercholesterolemia

High serum cholesterol has been frequently reported in patients with arterial hypertension in whom it might influence the blood pressure control. The aim of this study was to compare the extent of blood pressure changes in 41 patients with hypertension and hypercholesterolemia, taking antihypertensive drugs and treated for 3 months with statins (HC-S; pravastatin or simvastatin) and compared with matched controls with high (HC-D; 44) or normal serum cholesterol (NC-D; 45) undergoing antihypertensive treatment combined with dietary treatment alone. After 3 months of follow-up, a greater reduction of systolic (SBP) and diastolic (DBP) blood pressure values was observed in HC-S patients (ASBP/DBP, -11.3 +/-3/-10.6 +/- 2%) when compared with both HC-D (deltaSBP/DBP, -6.6 +/- 2/-6.1 +/- 2%; p < 0.05) and NC-D (deltaSBP/DBP, -6.9 +/- 2/-6.8 +/- 1.5%; p < 0.05). In statin-treated patients, a slight linear relation has been found between the percentage changes in DBP and those in plasma total cholesterol (R = 0.37, p = 0.043), whereas no relation was found with SBP changes (R =0.11; p = 0.35). In conclusion, the results of this study demonstrate that the use of statins in combination with antihypertensive drugs can improve blood pressure control in patients with uncontrolled hypertension and high serum cholesterol levels. The additional blood pressure reduction observed in patients treated with statins is clinically relevant and only partially related to the lipid-lowering effect.

Effects of the administration of an angiotensin-converting enzyme inhibitor during the acute phase of myocardial infarction in patients with arterial hypertension. SMILE Study Investigators. Survival of Myocardial Infarction Long-term Evaluation

A positive history of arterial hypertension (HBP) is present in as many as 30% of patients with acute myocardial infarction (AMI) and their clinical outcome could be greatly improved by drugs enhancing blood pressure control and preserving ventricular function. The aim of the present study was to evaluate the importance of a history of HBP on the clinical efficacy of early treatment with the angiotensin-converting enzyme (ACE) inhibitor zofenopril in patients with anterior AMI. We summarize the results of a post-hoc analysis of data from the Survival of Myocardial Infarction Long-term Evaluation (SMILE) study, which randomly evaluated the efficacy of zofenopril given within 24 h of symptom onset to patients with anterior AMI not undergoing thrombolysis. Of 1441 patients who entered the study, 565 (39.2%) had a history of HBP. The mean follow-up time was 12 months and the main outcome measures were 6-week combined occurrence of death and severe congestive heart failure (CHF) and 1-year mortality. After 6-week of treatment with zofenopril the relative risk of death or severe CHF was 0.60 (95% confidence interval [CI]: 0.45-0.81; 2P < .05) in the hypertensive group and 0.89 (0.74-1.08; 2P = .62) for normotensive patients, whereas the 1-year risk of death was 0.61 (95% CI: 0.23,0.89; 2P < .05) and 0.77 (95% CI: 0.52-1.17; 2P = .22), respectively. The 6-week prevalence of mild-to-moderate CHF was also significantly reduced by zofenopril in the hypertensive population (14.1% v 9.4%; 2P < .05). The present data suggest that treatment with zofenopril started within 24 h of the onset of anterior AMI could be highly beneficial in patients with a history of HBP.

[Clinical approach to the hypertensive patient. New guidelines]

Prospective observational studies clearly show that the risks of stroke, coronary artery disease, and premature death are directly related to blood pressure levels. Yet as the results of prospective randomized intervention studies have indicated, these risks are reduced by effective blood pressure control. Over a 5-year period, an average reduction of 5-6 mmHg in diastolic blood pressure and of 10-12 mmHg in systolic blood pressure is associated with a 38% decrease in risk of stroke and a 16% decrease in risk of coronary heart disease. Although awareness of hypertension has increased markedly, and the number of patients treated for this condition has approximately doubled over the last 20 years, premature morbidity and mortality remain higher than in the normotensive population. This situation may arise from the inadequate level of blood pressure control achieved in many patients. Thus, although delineating theoretical rules to treat hypertension seems relatively easy, in real life it is not always possible to adhere to them. This difficulty highlights the need for appropriate guidelines in clinical practice. A number of national groups as well as the World Health Organization and the International Society of Hypertension have recently published recommendations for the diagnosis and treatment of hypertension. Physicians must strive to improve the management of hypertension and remember that a thorough clinical evaluation, treatment of associated cardiovascular risk factors, prevention of target organ damage, and good patient compliance are key elements affecting the success of therapy.