Does aspirin use adversely influence intermediate-term postdischarge outcomes for hospitalized patients who are treated with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers? Findings from Organized Program to Facilitate Life-Saving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF)

Interactions between the Cyclooxygenase Metabolic Pathway and the Renin-Angiotensin-Aldosterone Systems: Their Effect on Cardiovascular Risk, from Theory to the Clinical Practice

Coronary artery disease (CAD) and stroke are the most common and serious long-term complications of hypertension. Acetylsalicylic acid (ASA) significantly reduces their incidence and cardiovascular mortality. The RAAS activation plays an important role in pathogenesis of CVD, resulting in increased vascular resistance, proliferation of vascular-smooth-muscle-cells, and cardiac hypertrophy. Drugs acting on the renin-angiotensin-aldosterone system (RAAS) are demonstrated to reduce cardiovascular events in population with cardiovascular disease (CVD). The cyclooxygenase inhibitors limit the beneficial effect of RAAS-inhibitors, which in turn may be important in subjects with hypertension, CAD, and congestive heart failure. These observations apply to most of nonsteroidal anti-inflammatory drugs and ASA at high doses. Nevertheless, there is no strong evidence confirming presence of similar effects of cardioprotective ASA doses. The benefit of combined therapy with low-doses of ASA is-in some cases-significantly higher than that of monotherapy. So far, the significance of ASA in optimizing the pharmacotherapy remains not fully established. A better understanding of its influence on the particular CVD should contribute to more precise identification of patients in whom benefits of ASA outweigh the complication risk. This brief review summarizes the data regarding usefulness and safety of the ASA combination with drugs acting directly on the RAAS.

Aspirin Use in Heart Failure

Background—

Aspirin use in heart failure (HF) is controversial. The drug has proven benefit in comorbidities associated with HF; however, retrospective analysis of angiotensin-converting enzyme inhibitor trials and prospective comparisons with warfarin have shown increased risk of morbidity with aspirin use. This study aims to evaluate the association of low-dose aspirin with mortality and morbidity risk in a large community-based cohort.

Methods and Results—

This was a retrospective cohort study of patients attending an HF disease management program. Aspirin use at baseline and its association with mortality and HF hospitalization in the population was examined. Of 1476 patients (mean age, 70.4±12.4 years; 63% men), 892 (60.4%) were prescribed aspirin. Low-dose aspirin (75 mg/d) was prescribed to 828 (92.8%) patients. Median follow-up time was 2.6 (0.8–4.5) years. During the follow-up period, 464 (31.4%) patients died. In adjusted analysis, low-dose aspirin use was associated with reduced mortality risk compared with nonaspirin use (hazard ratio=0.58; 95% confidence interval, 0.46–0.74), and this was confirmed by a propensity-matched subgroup analysis. Low-dose aspirin use was associated with reduced risk of HF hospitalization compared with nonaspirin use in the total population (adjusted hazard ratio=0.70; 95% confidence interval, 0.54–0.90). In adjusted analysis, there was no difference in mortality or HF hospitalization between high-dose aspirin users (>75 mg/d) and nonaspirin users.

Conclusions—

In this study, low-dose aspirin therapy was associated with a significant reduction in mortality and morbidity risk during long-term follow-up. These results suggest that low-dose aspirin may have a continuing role in secondary prevention in HF and underline the need for more trials of low-dose aspirin use in HF.

Heart failure: clinical problem and management issues

Heart failure (HF) often presents as dyspnea either with exertion and/or recumbency. Patients also experience dependent swelling and fatigue. Measurement of the left ventricular ejection fraction (LVEF) identifies HF patients who may respond to pharmacologic therapy and/or electrophysiologic device implantation. Angiotension converting enzyme inhibitors, beta blockers, and aldosterone inhibitors can significantly lower the mortality and morbidity of HF in patients with an LVEF less than 35%. Cardiac defibrillators and biventricular pacemakers can also improve outcomes in selected patients with a decreased LVEF. The authors provide a guide for therapeutic decisions based on the inclusion criteria of the major clinical trials.

Data sources for heart failure comparative effectiveness research

Existing data sources for heart failure research offer advantages and disadvantages for CER. Clinical registries collect detailed information about disease presentation, treatment, and outcomes on a large number of patients and provide the "real-world" population that is the hallmark of CER. Data are not collected longitudinally, however, and follow-up is often limited. Large administrative datasets provide the broadest population coverage with longitudinal outcomes follow-up but lack clinical detail. Linking clinical registries with other databases to assess longitudinal outcomes holds great promise. The Federal Coordinating Council for Comparative Effectiveness Research recommends further efforts on longitudinal linking of administrative or EHR-based databases, patient registries, private sector databases (particularly those with commercially insured populations that are not covered under federal and state databases), and other relevant data sources containing pharmacy, laboratory, adverse events, and mortality information. Advancing the infrastructure to provide robust, scientific data resources for patient-centered CER must remain a priority.