Interaction between Aspirin and ACE Inhibitors in Patients with Heart Failure

The effect of diclofenac sodium intoxication on the cardiovascular system in rats

OBJECTIVES

Diclofenac sodium (DS) is a widely used nonsteroidal anti-inflammatory drug. Although its high doses are known to cause toxic effects in many tissues including liver and kidney, the effects on the cardiovascular system (CVS) have not been fully elucidated yet. Therefore, this study aimed to investigate the effect of DS on CVS.

METHODS

The Control group did not receive medication; however, a single dose of 240 mg/kg DS was administered orally to the DS group. Electrocardiography (ECG) measurements were performed in all animals before (0thhour) and after (1st,6th,12th,24thhour) intoxication. After 24 h, All animals were sacrificed. Biochemical (malondialdehyde [MDA], and glutathione (GSH), Apelin, Elabela, Meteorin, Endoglin, Keap1, and Nrf2) and histopathological analyzes were performed on heart tissue samples.

RESULTS

ECG results showed that there was a statistically significant increase in QTc, QRS, and heart rate at the 12th and 24th hours in the DS group. The biochemical analysis showed that GSH, Apelin, Keap1, and NRF2 values decreased significantly while Meteorin and Endoglin levels increased in the DS group. When histopathological results were evaluated, distinct lesions were observed in the DS group.

CONCLUSION

In conclusion, high doses of DS intake can cause adverse effects on and damage to CVS.

Aspirin Does Not Increase Heart Failure Events in Heart Failure Patients: From the WARCEF Trial

OBJECTIVES

The aim of this study was to determine whether aspirin increases heart failure (HF) hospitalization or death in patients with HF with reduced ejection fraction receiving an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB).

BACKGROUND

Because of its cyclooxygenase inhibiting properties, aspirin has been postulated to increase HF events in patients treated with ACE inhibitors or ARBs. However, no large randomized trial has addressed the clinical relevance of this issue.

METHODS

We compared aspirin and warfarin for HF events (hospitalization, death, or both) in the 2,305 patients enrolled in the WARCEF (Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction) trial (98.6% on ACE inhibitor or ARB treatment), using conventional Cox models for time to first event (489 events). In addition, to examine multiple HF hospitalizations, we used 2 extended Cox models, a conditional model and a total time marginal model, in time to recurrent event analyses (1,078 events).

RESULTS

After adjustment for baseline covariates, aspirin- and warfarin-treated patients did not differ in time to first HF event (adjusted hazard ratio: 0.87; 95% confidence interval: 0.72 to 1.04; p = 0.117) or first hospitalization alone (adjusted hazard ratio: 0.88; 95% confidence interval: 0.73 to 1.06; p = 0.168). The extended Cox models also found no significant differences in all HF events or in HF hospitalizations alone after adjustment for covariates.

CONCLUSIONS

Among patients with HF with reduced ejection fraction in the WARCEF trial, there was no significant difference in risk of HF events between the aspirin and warfarin-treated patients. (Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial [WARCEF]; NCT00041938).

Zofenopril and Ramipril in Combination with Acetyl Salicylic Acid in Postmyocardial Infarction Patients with Left Ventricular Systolic Dysfunction: A Retrospective Analysis of the SMILE-4 Randomized, Double-Blind Study in Diabetic Patients

OBJECTIVE

In the SMILE-4 study, zofenopril + acetyl salicylic acid (ASA) was more effective than ramipril + ASA on 1-year prevention of major cardiovascular events (MACE) in patients with acute myocardial infarction complicated by left ventricular dysfunction. In this retrospective analysis, we evaluated drug efficacy in subgroups of patients, according to a history of diabetes mellitus.

METHODS

The primary study endpoint was 1-year combined occurrence of death or hospitalization for cardiovascular causes. Diabetes was defined according to medical history (previous known diagnosis).

RESULTS

A total of 562 of 693 (81.0%) patients were classified as nondiabetics and 131 (18.9%) as diabetics. The adjusted rate of MACE was lower under zofenopril than under ramipril in both nondiabetics [27.9% vs. 34.9% ramipril; odds ratio, OR and 95% confidence interval: 0.55 (0.35, 0.86)] and diabetics [30.9% vs. 41.3%; 0.56 (0.18, 1.73)], although the difference was statistically significant only for the nondiabetic group (P = 0.013). Zofenopril was superior to ramipril as regards to the primary study endpoint in the subgroup of 157 patients with uncontrolled blood glucose (≥ 126 mg/dL), regardless of a previous diagnosis of diabetes [0.31 (0.10, 0.90), P = 0.030]. Zofenopril significantly reduced the risk of hospitalization for cardiovascular causes in both nondiabetics [0.64 (0.43, 0.96), P = 0.030] and diabetics [0.38 (0.15, 0.95), P = 0.038], whereas it was not better than ramipril in terms of prevention of cardiovascular deaths.

CONCLUSIONS

This retrospective analysis of the SMILE-4 study confirmed the good efficacy of zofenopril plus ASA in the prevention of long-term MACE also in the subgroup of patients with diabetes mellitus.

Interaction between cyclooxygenase and the renin-angiotensin-aldosterone system: rationale and clinical relevance

Increased understanding of pathophysiological mechanisms of cardiovascular diseases has shown that the renin-angiotensin-aldosterone system (RAAS) is activated in this setting and suggests a central role for the angiotensin-converting enzyme (ACE). ACE transforms angiotensin I (Ang I) to angiotensin II (Ang II), and also promotes the degradation of bradykinin into inactive metabolites. These bradykinins stimulate nitric oxide synthesis and vasodilatator prostaglandin synthesis via a cyclooxygenase (COX) pathway.

COX inhibitors may therefore be deleterious in cardiovascular disease and/or counteract part of ACE inhibitor (ACE-I) efficacy. This has been clearly demonstrated with non-steroidal anti-inflammatory drugs (NSAIDs), including high-dose aspirin, in avoiding their use in such patients. hypertension, coronary artery disease and chronic heart failure (CHF); most guidelines recommend avoiding their use in such patients.

Theoretically, this effect is dose-mediated and the existence of an identical deleterious effect with low-dose aspirin has been an area of intense debate. In this article, we review studies, most of them conducted in CHF, that pointed out such a possible deleterious effect and a counteraction of ACE-Is with low-dose aspirin , using various criteria of assessment.

However, there are no prospective long-term studies that have validated such an effect, and the role of other anti-aggregating agents has not been evaluated. Until such studies are published, the use of low-dose aspirin (100 mg/day) in such patients can be recommended.

Aspirin in the perioperative period: a review of the recent literature

PURPOSE OF REVIEW

The indications for aspirin (ASA) for both primary and secondary prevention of thrombotic events continue to evolve. We review some of these indications and the recent literature regarding the perioperative administration of ASA.

RECENT FINDINGS

ASA for primary prevention of cardiac ischemia, stroke, cancer, and death remains controversial. When used for primary prevention, ASA may be safely discontinued perioperatively. Patients with coronary or carotid artery stents should continue to receive ASA perioperatively. For patients with ischemic heart disease currently receiving ASA for secondary prevention of cardiac ischemia and stroke undergoing general surgery, orthopedic surgery, ophthalmological surgery, cardiovascular surgery, major vascular surgery, or a urological procedure, continuation of ASA is probably well tolerated, but further study is required. There is no indication to initiate ASA perioperatively in patients with stable ischemic heart disease as the risks outweigh the benefits. Until further data become available, decisions regarding the perioperative continuation of ASA should be made on a case-by-case risk-benefit analysis.

SUMMARY

The continuation or discontinuation of ASA perioperatively remains a complicated issue. Further, well designed trials are needed for additional clarification.

Zofenopril and ramipril and acetylsalicylic acid in postmyocardial infarction patients with left ventricular systolic dysfunction: a retrospective analysis in hypertensive patients of the SMILE-4 study

BACKGROUND

Antecedent hypertension represents a risk factor for adverse outcomes in survivors of acute myocardial infarction (AMI). Prognosis of such patients might be greatly improved by drugs enhancing blood pressure control. In the present retrospective analysis of the randomized, double-blind, parallel-group, SMILE-4 study we compared the efficacy of zofenopril 60 mg and acetylsalicylic acid (ASA) 100 mg versus ramipril 10 mg and ASA in patients with AMI complicated by left ventricular dysfunction, classified according to a history of hypertension.

METHODS

The primary study end-point was 1-year combined occurrence of death or hospitalization for cardiovascular causes. Hypertension was defined according to medical history and current blood pressure values at entry and could be determined in 682 of 716 patients of the intention-to-treat analysis.

RESULTS

One hundred and fifty-seven patients (23%) were normotensives and 525 (77%) hypertensives. In the normotensive population the primary end-point occurred in 19 of 76 zofenopril-treated patients (25%) and in 23 of 81 ramipril-treated patients (28%) [odds ratio (95% confidence interval): 0.84 (0.41-1.71), P = 0.631]. In the hypertensive population, major cardiovascular outcomes were reported in 84 of 273 zofenopril-treated patients (31%) and in 99 of 252 ramipril-treated patients (39%), with a 31% significantly (P = 0.041) lower risk with zofenopril [0.69 (0.48-0.99)]. The superiority of zofenopril versus ramipril was particularly evident in patients with isolated systolic hypertension [n = 131, 0.48 (0.23-0.99), P = 0.045].

CONCLUSION

This retrospective analysis of the SMILE-4 study confirmed the good efficacy of zofenopril and ASA in the prevention of long-term cardiovascular outcomes also in the subgroup of patients with hypertension.

Comparison between zofenopril and ramipril in combination with acetylsalicylic acid in patients with left ventricular systolic dysfunction after acute myocardial infarction: results of a randomized, double-blind, parallel-group, multicenter, European study (SMILE-4)

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) are largely employed for treating patients with left ventricular dysfunction (LVD), but their efficacy may be negatively affected by concomitant administration of acetylsalicylic acid (ASA), with some difference among the different compounds.

HYPOTHESIS

The interaction between ASA and the two ACEIs zofenopril and ramipril may result in a different impact on survival of cardiac patients, due to differences in the pharmacological properties of the two ACEIs.

METHODS

This phase IIIb, randomized, double-blind, parallel-group, multicenter, European study compared the safety and efficacy of zofenopril (60 mg/day) and ramipril (10 mg/day) plus ASA (100 mg/day), in 771 patients with LVD (clinical signs of heart failure or a left ventricular ejection fraction <45%) following acute myocardial infarction (AMI). The primary study end point was 1-year combined occurrence of death or hospitalization for cardiovascular causes.

RESULTS

In the intention-to-treat population, the primary outcome was significantly reduced by zofenopril (n = 365) vs ramipril (n = 351) (odds ratio [OR]: 0.70, and 95% confidence interval [CI]: 0.51-0.96; P = 0.028) as a result of a decrease in cardiovascular hospitalization (OR: 0.64,95% CI: 0.46-0.88; P = 0.006). Mortality rate was not significantly different between the 2 treatments (OR: 1.51, 95% CI: 0.70-3.27; P = 0.293). Blood pressure values did not significantly change during the 1-year follow-up. N-terminal pro-brain natriuretic peptide levels were progressively reduced during the study, with no statistically significant between-treatment differences. Proportion of patients with deterioration of renal function during the study was similar between the 2 groups. Drug safety profile was comparable between treatments.

CONCLUSIONS

In patients with LVD following AMI, the efficacy of zofenopril associated with ASA was superior to that of ramipril plus ASA, indicating some important clinical implications for the future use of ACEIs in patients with LVD or overt heart failure.

Risk of potential drug-drug interactions among Brazilian elderly: a population-based, cross-sectional study

BACKGROUND

Drug-drug interactions (DDIs) are one of the main causes of adverse reactions related to medications, being responsible for up to 23% of hospital admissions. However, only a few studies have evaluated this problem in elderly Brazilians.

OBJECTIVES

To determine the prevalence of potential DDIs (PDDIs) in community-dwelling elderly people in Brazil, analyse these interactions with regard to severity and clinical implications, and identify associated factors.

METHODS

A population-based cross-sectional study was carried out involving 2143 elderly (aged >or=60 years) residents of the metropolitan area of Sao Paulo, Brazil. Data were obtained from the SABE (Saúde, Bem estar e Envelhecimento [Health, Well-Being, and Aging]) survey, which is a multicentre study carried out in seven countries of Latin America and the Caribbean, coordinated by the Pan-American Health Organization. PDDIs were analysed using a computerized program and categorized according to level of severity, onset, mechanism and documentation in the literature. The STATA software statistical package was used for data analysis, and logistic regression was conducted to determine whether variables were associated with PDDIs.

RESULTS

Analysis revealed that 568 (26.5%) of the elderly population included in the study were taking medications that could lead to a DDI. Almost two-thirds (64.4%) of the elderly population exposed to PDDIs were women, 50.7% were aged >or=75 years, 71.7% reported having fair or poor health and 65.8% took 2-5 medications. A total of 125 different PDDIs were identified; the treatment combination of an ACE inhibitor with a thiazide or loop diuretic (associated with hypotension) was the most frequent cause of PDDIs (n = 322 patients; 56.7% of individuals with PDDIs). Analysis of the PDDIs revealed that 70.4% were of moderate severity, 64.8% were supported by good quality evidence and 56.8% were considered of delayed onset. The multivariate analysis showed that the risk of a PDDI was significantly increased among elderly individuals using six or more medications (odds ratio [OR] 3.37) and in patients with hypertension (OR 2.56), diabetes mellitus (OR 1.73) or heart problems (OR 3.36).

CONCLUSIONS

Approximately one-quarter of the elderly population living in Sao Paulo could be taking two or more potentially interacting medicines. Polypharmacy predisposes elderly individuals to PDDIs. More than half of these drug combinations (57.6%, n = 72) were part of commonly employed treatment regimens and may be responsible for adverse reactions that compromise the safety of elderly individuals, especially at home. Educational initiatives are needed to avoid unnecessary risks.

Randomized trial of warfarin, aspirin, and clopidogrel in patients with chronic heart failure: the Warfarin and Antiplatelet Therapy in Chronic Heart Failure (WATCH) trial

BACKGROUND

Chronic heart failure remains a major cause of mortality and morbidity. The role of antithrombotic therapy in patients with chronic heart failure has long been debated. The objective of this study was to determine the optimal antithrombotic agent for heart failure patients with reduced ejection fractions who are in sinus rhythm.

METHODS AND RESULTS

This prospective, randomized clinical trial of open-label warfarin (target international normalized ratio of 2.5 to 3.0) and double-blind treatment with either aspirin (162 mg once daily) or clopidogrel (75 mg once daily) had a 30-month enrollment period and a minimum of 12 months of treatment. We enrolled 1587 men and women >/=18 years of age with symptomatic heart failure for at least 3 months who were in sinus rhythm and had left ventricular ejection fraction of

CONCLUSIONS

The primary outcome measure and the mortality data do not support the primary hypotheses that warfarin is superior to aspirin and that clopidogrel is superior to aspirin.

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Key Words Collapse

MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Aspirin/administration & dosage
• Chronic Disease
• Clopidogrel
• Death
• Double-Blind Method
• Female
• Fibrinolytic Agents/administration & dosage
• Heart Failure/complications
• Heart Failure/drug therapy
• Heart Failure/mortality
• Humans
• Male
• Middle Aged
• Myocardial Infarction
• Stroke
• Stroke Volume
• Ticlopidine/administration & dosage
• Ticlopidine/analogs & derivatives
• Warfarin/administration & dosage

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Grants Collapse

Affiliation(s)

Barry M Massie Department of Veterans Affairs, San Francisco, CA, USA
Joseph F Collins
Susan E Ammon
Paul W Armstrong
John G F Cleland
Michael Ezekowitz
Syed M Jafri
William F Krol
Christopher M O'Connor
Kevin A Schulman
Koon Teo
Stuart R Warren

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The Warfarin and Antiplatelet Therapy in Heart Failure Trial (WATCH): rationale, design, and baseline patient characteristics

BACKGROUND

The role of anticoagulation in patients with chronic heart failure has long been an area of interest and controversy. Traditionally the goal of anticoagulation has been to prevent embolic events, but recent trials also demonstrated that oral anticoagulation also prevents vascular events in patients with prior myocardial infarction, who constitute the majority of heart failure patients. Although antiplatelet agents also reduce postinfarction vascular events, few data are available in heart failure patients, and some evidence suggests that aspirin may also have the potential to worsen heart failure morbidity and mortality, possibly by interfering with the effects of angiotensin-converting enzyme inhibitors. Methods and results The Warfarin and Antiplatelet Therapy in Chronic Heart Failure (WATCH) trial was undertaken to determine the optimal antithrombotic agent for heart failure patients. WATCH was a prospective-randomized trial in which symptomatic heart failure patients in sinus rhythm with ejection fractions < or =35% taking angiotensin-converting enzyme inhibitors (unless not tolerated) and diuretics were randomized to open-label warfarin (target International Normalized Ratio 2.5-3.0) or double-blind antiplatelet therapy with aspirin 162 mg or clopidogrel 75 mg. Two primary comparisons were specified: anticoagulation with warfarin versus antiplatelet therapy with aspirin and antiplatelet therapy with clopidogrel versus antiplatelet therapy with aspirin. The primary outcome is the composite of death from all causes, nonfatal myocardial infarction, and nonfatal stroke analyzed as time to first event using the intent-to-treat approach. The secondary endpoint was the broader composite of death from all causes, nonfatal myocardial infarction, non-fatal stroke, and hospitalizations for worsening heart failure, unstable angina pectoris, and systemic or pulmonary artery embolic events. Additional prespecified analyses include heart failure events, coronary events, and resource utilization.

CONCLUSIONS

Although the trial was designed to enter 4500 patients, it was terminated 18 months prematurely in June 2003 by the VA Cooperative Study Program because of poor enrollment with a resulting reduction of its power to achieve its original objective. This manuscript describes the study rationale, protocol design, and the baseline characteristics of the 1587 patients who were entered into the study. The WATCH trial will help define the optimal approach to antithrombotic therapy in the contemporary management of patients with chronic heart failure resulting from left ventricular systolic dysfunction.

Potential drug-drug interactions in the medication of medical patients at hospital discharge

OBJECTIVE

Information on the frequency of drug combinations with the potential to induce dangerous drug-drug interactions (DDIs) in patients discharged from the hospital is scarce. With the present study, we assessed the frequency and potential clinical significance of DDIs in the prescriptions of discharged medical patients.

METHODS

We retrospectively screened the medication for potential DDIs of 500 patients consecutively discharged with at least two prescriptions using a computerised drug-interaction program.

RESULTS

The 500 patients (56.6% male, mean age 67.0+/-15.9 years, median length of stay 13 days) were prescribed a median of six drugs (range 2-18) at discharge. Three hundred patients (60.0%; 95% confidence interval 55.7-64.3%) had at least one potentially interacting drug combination. Of 747 potential DDIs at discharge overall, 402 (53.8%) were new at the time of discharge due to a change of the medication during the hospital stay. Of these, 72 (17.9%) were of potentially minor, 281 (69.9%) of moderate and 49 (12.2%) of major severity. Of 44 patients with a potential DDI with major severity, 1 patient was re-hospitalised within 2 months after discharge due to a probable drug-related problem associated with the potential DDI.

CONCLUSIONS

Using a computerised drug-interaction program, a high proportion of patients was detected with at least one potential DDI in the medication prescribed at discharge. However, the proportion of DDIs associated with potentially relevant clinical consequences appeared to be relatively low.

Risks versus Benefits of NSAIDs Including Aspirin in Myocarditis

NSAIDs, including aspirin (acetylsalicylic acid), are frequently used and effective in a broad variety of inflammatory diseases, i.e. rheumatic carditis and pericarditis. Myocarditis may constitute another suitable indication for NSAIDs in order to relieve the symptoms of the presumed viral infection or because pericardial effusion is often associated with this condition. However, concerns have been raised about their indiscriminate use in myocarditis. To clarify this issue, we conducted a systematic review of the literature concerning myocarditis, aspirin and NSAIDs. We examined five animal studies of NSAIDs (indomethacin and ibuprofen) and aspirin in coxsackievirus B3- and B4-induced myocarditis. These studies indicated a deleterious effect of NSAIDs and aspirin in this setting, demonstrating a 2- to 3-fold increase in inflammation, myocytes necrosis and even mortality when compared with placebo. This possible deleterious effect was more predominant when NSAIDs or aspirin were administered during the acute and subacute phases of myocarditis; however, it was still noted when NSAIDs were administered during the late phase of the disease (the effect of aspirin was not evaluated in late phase studies). According to these animal studies, such effect might be attributed to decreased viral clearance (possibly via interferon inhibition) and/or exaggerated cytotoxic response (via interleukin-2 or inhibition of suppressor cells factors) and/or coronary artery spasm. We found one animal study looking at autoimmune myocarditis and it did not demonstrate any beneficial or detrimental effect of aspirin. Moreover, recent data suggest that aspirin and NSAIDs may counteract part of the efficacy of ACE inhibitors and be deleterious in chronic heart failure. Taken together, these studies point to a possible deleterious effect of aspirin and NSAIDs in human myocarditis. In view of these animal studies and in the absence of controlled studies of aspirin or NSAIDs in human myocarditis, we do not recommend indiscriminate treatment with NSAIDs or high-dose aspirin in patients with myocarditis where there is no or minimal associated pericarditis.

Drug Interactions Between Herbal and Prescription Medicines

Until reports of interactions between St John's wort and drugs such as digoxin, warfarin, protease inhibitors and oral contraceptives began to appear, very few herb-drug interactions were documented. These are now becoming more common, although still rare compared with drug-drug interactions. In the absence of hard data, potential interactions are being highlighted, and this review attempts to distinguish between the speculative and the proven. The subject is approached from a therapeutic point of view since in most cases the patient is already taking one or more prescription drugs, and the question is whether or not it is safe for a particular herb to be added to the regimen. Although many of the examples of herb-drug interactions are minor or theoretical at present, the fact remains that some are serious and life threatening, and these almost exclusively concern cyclosporin, anticoagulants, digoxin, antidepressants and protease inhibitors, taken with the herb St John's wort. Ginkgo and ginseng are implicated in a number of reports, but many of these are unsubstantiated. To date, the cardiovascular, central nervous and immune systems are the most common therapeutic categories cited in the literature and other than those, examples are very limited. Although many herbal drugs have good safety profiles, it must be borne in mind that herbal supplements are intended to be taken over an extended period of time, which provides the opportunity for enzyme induction and other mechanisms of interaction to take effect.

Interaction between aspirin and ACE Inhibitors: resolving discrepancies using a meta-analysis

BACKGROUND

Recently, studies have attempted to explore the interaction between ACE inhibitors and aspirin (acetylsalicylic acid) when both drugs are used concomitantly to reduce mortality in patients with coronary artery disease. Results have been conflicting due, in part, to sub-optimal methods used to explore this interaction.

METHODS

We reviewed systematically all studies on mortality in patients treated with ACE inhibitors and aspirin and conducted a meta-analysis in order to explore the interaction between both drugs and resolve discrepancies. To be included, each study had to provide data on mortality of patients who received both drugs, either drug and no drug. These data were necessary to calculate the synergy index (S) and its 95% confidence interval (CI) that we used to quantify the effect due to interaction between ACE inhibitors and aspirin. After testing for heterogeneity of effects, we pooled the S values from the individual studies into one summary measure. Subsequently, we compared our results with those obtained through the most common but incorrect method of evaluating interaction. This method uses significance testing of the relative risk of mortality when a 'product term' between ACE inhibitors and aspirin is entered in a logistic regression model.

RESULTS

Eight studies met the inclusion criteria. The pooled synergy index S indicates slight but precise antagonism between ACE inhibitors and aspirin (S = 0.91; 95% CI 0.80 to 1.03). In contrast, the pooled 'product term' is not significant and would have lead to the conclusion of absence of interaction (p = 0.15).

CONCLUSION

There seems to be an antagonistic interaction between ACE inhibitors and aspirin. Former discrepancies were due to inadequate assessment of interaction. Results from the Studies on Left Ventricular Dysfunction (SOLVD) and Heart Outcome Prevention Evaluation (HOPE) trials that assessed the effect of combined administration of ACE inhibitors and aspirin were not included in this meta-analysis because those trials did not provide enough data to compute the S statistic. It is possible that results from on-going trials such as Women's Atovarstatin Trial on Cholesterol (WATCH) will shed more light on ACE inhibitor and aspirin interaction in the future.

Low-dose aspirin does not interfere with the blood pressure-lowering effects of antihypertensive therapy

BACKGROUND

It has been reported that aspirin (ASA) may interfere with the blood pressure (BP)-lowering effect of various antihypertensive agents and attenuate the beneficial effects of angiotensin-converting enzyme (ACE) inhibitors in patients with congestive heart failure.

METHODS AND RESULTS

Data from the Hypertension Optimal Treatment (HOT) Study, in which 18 790 intensively treated hypertensive patients were randomized to either ASA 75 mg daily or placebo for 3.8 years (with a 15% reduction in cardiovascular events and a 36% reduction in myocardial infarction in ASA-treated patients), were reanalysed for the whole group of patients and for various subgroups with particular attention to the possible effects of ASA on BP and renal function. In ASA-treated and placebo-treated patients: (1) systolic blood pressure (SBP) and diastolic blood pressure (DBP) values achieved with antihypertensive treatment were superimposable, with clinically irrelevant differences; (2) these superimposable SBP and DBP were achieved with antihypertensive therapies, that were quantitatively and qualitatively similar, and (3) changes in serum creatinine and in estimated creatinine clearance and the number of patients developing renal dysfunction were also similar. Furthermore, the cardiovascular benefits of ASA were of the same magnitude in hypertensive patients receiving or not receiving ACE-inhibitors.

CONCLUSIONS

Even long-term, low-dose ASA does not interfere with the BP-lowering effect of antihypertensive agents, including combinations with ACE inhibitors, or with renal function. No negative interaction occurs between ACE inhibition and the cardiovascular benefits of small dose of ASA. Our conclusions cannot be extended to larger doses of ASA, or to patients with congestive heart failure.