Alcohol consumption, atherosclerotic progression, and prognosis among patients with coronary artery bypass grafts

Alcohol use disorders and the heart

Alcohol use is an important preventable and modifiable cause of non-communicable disease, and has complex effects on the cardiovascular system that vary with dose. Observational and prospective studies have consistently shown a lower risk of cardiovascular and all-cause mortality in people with low levels of alcohol consumption when compared to abstainers (the 'J'-shaped curve). Maximum potential benefit occurs at 0.5 to one standard drinks (7-14 g pure ethanol) per day for women (18% lower all-cause mortality, 95% confidence interval (CI) = 13-22%) and one to two standard drinks (14-28 g ethanol) per day for men (17% lower all-cause mortality, 95% CI = 15-19%). However, this evidence is contested, and overall the detrimental effects of alcohol far outweigh the beneficial effects, with the risk of premature mortality increasing steadily after an average consumption of 10 g ethanol/day. Blood pressure (BP) is increased by regular alcohol consumption in a dose-dependent manner, with a relative risk for hypertension (systolic BP > 140 mm Hg or diastolic > 90 mm Hg) of 1.7 for 50 g ethanol/day and 2.5 at 100 g/day. Important reductions in BP readings can be expected after as little as 1 month of abstinence from alcohol. Heavy alcohol consumption in a binge pattern is associated with the development of acute cardiac arrhythmia, even in people with normal heart function. Atrial fibrillation is the most common arrhythmia associated with chronic high-volume alcohol intake, and above 14 g alcohol/day the relative risk increases 10% for every extra standard drink (14 g ethanol). Ethanol and its metabolites have toxic effects on cardiac myocytes, and alcoholic cardiomyopathy (ACM) accounts for a third of all cases of non-ischaemic dilated cardiomyopathy. Screening people drinking alcohol above low-volume levels and delivering a brief intervention may prevent the development of cardiovascular complications. Although people with established cardiovascular disease show improved outcomes with a reduction to low-volume alcohol consumption, there is no safe amount of alcohol to drink and patients with ACM should aim for abstinence in order to optimize medical treatment.

Effect of Alcohol Consumption on Cardiovascular Health

PURPOSE OF REVIEW

This review aims to discuss the effect of alcohol consumption on various cardiovascular (CV) diseases and CV mortality.

RECENT FINDINGS

Alcohol intake has consistently shown a J- or U-shaped relationship with several cardiovascular diseases. Light to moderate alcohol intake has been associated with lower risk of coronary artery disease, heart failure (HF), as well as CV mortality. On the other hand, heavy consumption has been associated with deleterious CV outcomes including increased mortality. However, the evidence is based from observational and population-based studies where risk of confounding cannot be excluded even after meticulous methodological approaches. This is compounded by conflicting data such as higher risk of certain CV diseases like HF in former drinkers compared to abstainers. Further, Mendelian randomization studies using genetic polymorphisms in enzymes have recently questioned the beneficial association of low-moderate drinking with CV system. There has been substantial and consistent evidence that light to moderate alcohol consumption have beneficial effect on overall cardiovascular profile and mortality. However, there are considerable limitations in the reported literature to determine a strong causality of a protective effect of moderate alcohol consumption by itself. Further robust studies or possibly a well-structured randomized controlled could bring an end to this debate.

Alcohol consumption and mortality in patients undergoing coronary artery bypass graft (CABG)-a register-based cohort study

BACKGROUND

Previous studies have shown that compared with abstinence and heavy drinking, moderate alcohol consumption is associated with a reduced risk of mortality among the general population and patients with heart failure and myocardial infarction. We examined the association between alcohol consumption and mortality in coronary artery bypass graft (CABG) patients.

METHOD

We studied 1,919 first-time CABG patients using data on alcohol consumption and mortality obtained from Danish national registers from March 2006 to October 2011. Alcohol consumption was divided into the following groups: abstainers (0 units/week), moderate consumers (1-14 units/week), moderate-heavy drinkers (15-21 units/week) and heavy drinkers (>21 units/week). Hazard ratios (HR) of all-cause mortality were calculated using Cox proportional hazard regression analysis.

RESULTS

The median follow-up was 2.2 years [IQR 2.0]. There were 112 deaths, of which 96 (86 %) were classified as cardiovascular. Adjustments for age and sex showed no increased risk of all-cause mortality for the abstainers (HR 1.61, 95 % CI, 1.00-2.58) and moderate-heavy drinkers (HR 1.40, 95 % CI, 0.73-2.67) compared with moderate consumers. However, heavy drinkers had a high risk of all-cause mortality compared with moderate consumers (HR 2.44, 95 % CI, 1.47-4.04). A full adjustment showed no increase in mortality for the abstainers (HR 1.59, 95 % CI, 0.98-2.57) and moderate-heavy drinkers (HR 1.68, 95 % CI, 0.86-3.29), while heavy drinkers were associated with an increased mortality rate (HR 1.88, 95 % CI, 1.10-3.21). There was no increased risk of 30-day mortality for the abstainers (HR 0.74, 95 % CI, 0.23-2.32), moderate-heavy drinkers (HR 0.36, 95 % CI, 0.07-1.93) and heavy drinkers (HR 2.20, 95 % CI, 0.65-7.36).

CONCLUSION

There was no increased risk of mortality for abstainers (0 units/week) or moderate-heavy drinkers (15-21 units/week) following a CABG. Only heavy drinking (>21 units/week) were significantly associated with an increased mortality rate. These results suggest that only heavy drinking present a risk factor among CABG patients.

Liver Function Tests Following Open Cardiac Surgery

Introduction: The cardiopulmonary bypass may have multiple systemic effects on the body organs as liver. This prospective study was planned to explore further the incidence and significance of this change.

Methods: Two hundred patients with coronary artery bypass grafting (CABG), were randomly selected for the study. Total and indirect bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase were measured preoperatively and at 24, 48 and 72 hours, following coronary artery bypass grafting. Postoperative value of the liver function tests with respect to hypothermia or hypotension were compared by one way analysis of variance for repeated measure and compared with t test. Patient’s characteristics with bilirubin value (≤1.5 mg or >1.5 mg) were compared with t test.

Results: A significant increase of total bilirubin, aspartate aminotransferase, and alkaline phosphatase were noted in the third postoperative day. Significant relation was seen between hypotension and alkaline phosphatase, and aspartate aminotransferase change but hypothermia had not affected alanine aminotransferase, total bilirubin and indirect bilirubin change. Pump time, alanine aminotransferase in third postoperative day and direct bilirubin in first and second day of postoperative period had significant relation with pre and post-operative bilirubin change.

Conclusion: Transient but not permanent alterations of hepatic enzymes after coronary artery bypass grafting presumably attributed to the decreased hepatic flow, hypoxia, or pump-induced inflammation.

HMG CoA reductase inhibitors (statins) for preventing acute kidney injury after surgical procedures requiring cardiac bypass

BACKGROUND

Acute kidney injury (AKI) is common in patients undergoing cardiac surgery among whom it is associated with poor outcomes, prolonged hospital stays and increased mortality. Statin drugs can produce more than one effect independent of their lipid lowering effect, and may improve kidney injury through inhibition of postoperative inflammatory responses.

OBJECTIVES

This review aimed to look at the evidence supporting the benefits of perioperative statins for AKI prevention in hospitalised adults after surgery who require cardiac bypass. The main objectives were to 1) determine whether use of statins was associated with preventing AKI development; 2) determine whether use of statins was associated with reductions in in-hospital mortality; 3) determine whether use of statins was associated with reduced need for RRT; and 4) determine any adverse effects associated with the use of statins.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 13 January 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared administration of statin therapy with placebo or standard clinical care in adult patients undergoing surgery requiring cardiopulmonary bypass and reporting AKI, serum creatinine (SCr) or need for renal replacement therapy (RRT) as an outcome were eligible for inclusion. All forms and dosages of statins in conjunction with any duration of pre-operative therapy were considered for inclusion in this review.

DATA COLLECTION AND ANALYSIS

All authors extracted data independently and assessments were cross-checked by a second author. Likewise, assessment of study risk of bias was initially conducted by one author and then by a second author to ensure accuracy. Disagreements were arbitrated among authors until consensus was reached. Authors from two of the included studies provided additional data surrounding post-operative SCr as well as need for RRT. Meta-analyses were used to assess the outcomes of AKI, SCr and mortality rate. Data for the outcomes of RRT and adverse effects were not pooled. Adverse effects taken into account were those reported by the authors of included studies.

MAIN RESULTS

We included seven studies (662 participants) in this review. All except one study was assessed as being at high risk of bias. Three studies assessed atorvastatin, three assessed simvastatin and one investigated rosuvastatin. All studies collected data during the immediate perioperative period only; data collection to hospital discharge and postoperative biochemical data collection ranged from 24 hours to 7 days. Overall, pre-operative statin treatment was not associated with a reduction in postoperative AKI, need for RRT, or mortality. Only two studies (195 participants) reported postoperative SCr level. In those studies, patients allocated to receive statins had lower postoperative SCr concentrations compared with those allocated to no drug treatment/placebo (MD 21.2 µmol/L, 95% CI -31.1 to -11.1). Adverse effects were adequately reported in only one study; no difference was found between the statin group compared to placebo.

AUTHORS' CONCLUSIONS

Analysis of currently available data did not suggest that preoperative statin use is associated with decreased incidence of AKI in adults after surgery who required cardiac bypass. Although a significant reduction in SCr was seen postoperatively in people treated with statins, this result was driven by results from a single study, where SCr was considered as a secondary outcome. The results of the meta-analysis should be interpreted with caution; few studies were included in subgroup analyses, and significant differences in methodology exist among the included studies. Large high quality RCTs are required to establish the safety and efficacy of statins to prevent AKI after cardiac surgery.

Alcohol and cardiovascular health: the dose makes the poison…or the remedy

Habitual light to moderate alcohol intake (up to 1 drink per day for women and 1 or 2 drinks per day for men) is associated with decreased risks for total mortality, coronary artery disease, diabetes mellitus, congestive heart failure, and stroke. However, higher levels of alcohol consumption are associated with increased cardiovascular risk. Indeed, behind only smoking and obesity, excessive alcohol consumption is the third leading cause of premature death in the United States. Heavy alcohol use (1) is one of the most common causes of reversible hypertension, (2) accounts for about one-third of all cases of nonischemic dilated cardiomyopathy, (3) is a frequent cause of atrial fibrillation, and (4) markedly increases risks of stroke-both ischemic and hemorrhagic. The risk-to-benefit ratio of drinking appears higher in younger individuals, who also have higher rates of excessive or binge drinking and more frequently have adverse consequences of acute intoxication (for example, accidents, violence, and social strife). In fact, among males aged 15 to 59 years, alcohol abuse is the leading risk factor for premature death. Of the various drinking patterns, daily low- to moderate-dose alcohol intake, ideally red wine before or during the evening meal, is associated with the strongest reduction in adverse cardiovascular outcomes. Health care professionals should not recommend alcohol to nondrinkers because of the paucity of randomized outcome data and the potential for problem drinking even among individuals at apparently low risk. The findings in this review were based on a literature search of PubMed for the 15-year period 1997 through 2012 using the search terms alcohol, ethanol, cardiovascular disease, coronary artery disease, heart failure, hypertension, stroke, and mortality. Studies were considered if they were deemed to be of high quality, objective, and methodologically sound.

Moderate alcohol use and health: a consensus document

AIMS

The aim of this consensus paper is to review the available evidence on the association between moderate alcohol use, health and disease and to provide a working document to the scientific and health professional communities.

DATA SYNTHESIS

In healthy adults and in the elderly, spontaneous consumption of alcoholic beverages within 30 g ethanol/d for men and 15 g/d for women is to be considered acceptable and do not deserve intervention by the primary care physician or the health professional in charge. Patients with increased risk for specific diseases, for example, women with familiar history of breast cancer, or subjects with familiar history of early cardiovascular disease, or cardiovascular patients should discuss with their physician their drinking habits. No abstainer should be advised to drink for health reasons. Alcohol use must be discouraged in specific physiological or personal situations or in selected age classes (children and adolescents, pregnant and lactating women and recovering alcoholics). Moreover, the possible interactions between alcohol and acute or chronic drug use must be discussed with the primary care physician.

CONCLUSIONS

The choice to consume alcohol should be based on individual considerations, taking into account the influence on health and diet, the risk of alcoholism and abuse, the effect on behaviour and other factors that may vary with age and lifestyle. Moderation in drinking and development of an associated lifestyle culture should be fostered.

Alcohol and the heart: to abstain or not to abstain?

Alcohol has been consumed by most societies over the last 7000 years. Abraham Lincoln said "It has long been recognized that the problems with alcohol relate not to the use of a bad thing, but to the abuse of a good thing." Light to moderate alcohol consumption reduces the incidence of coronary heart disease (CHD), ischemic stroke, peripheral arterial disease, CHD mortality, and all-cause mortality, especially in the western populations. However, heavy alcohol consumption is detrimental causing cardiomyopathy, cardiac arrhythmias, hepatic cirrhosis, pancreatitis, and hemorrhagic stroke. In this article, we review the effects of alcohol on CHD, individual cardiovascular risk factors, cardiomyopathy, and cardiac arrhythmias, including the most recent evidence of the effects of alcohol on CHD.

Self-reported anxiety and the risk of clinical events and atherosclerotic progression among patients with Coronary Artery Bypass Grafts (CABG)

BACKGROUND

Symptoms of anxiety are associated with increased risk of coronary artery disease and potentially poor prognosis among patients with existing coronary artery disease, but whether symptoms of anxiety influence atherosclerotic progression among such patients is uncertain. Accordingly, we evaluated the hypotheses that symptoms of anxiety are associated with adverse clinical outcomes and progression of atherosclerosis among individuals with previous coronary artery bypass graft (CABG) surgery and saphenous vein grafts enrolled in the Post-CABG Trial.

METHODS

The Post-CABG Trial randomized patients with a history of CABG surgery to either aggressive or moderate lipid lowering and to either warfarin or placebo. Patients were followed up for clinical end points and coronary angiography was conducted at enrollment and after a median follow-up of 4.3 years. Anxiety symptoms were assessed at enrollment using the state portion of the Spielberger State-Trait Anxiety Inventory (STAI) in 1317 patients.

RESULTS

In models adjusting for age, sex, race, treatment assignment and years since CABG surgery, a STAI score > or =40 was positively associated with risk of death or myocardial infarction (MI) (OR 1.55, 95% CI 1.01-2.36, P = .044). This association was attenuated slightly when depressive symptoms were included in the model, but lost statistical significance (P = .11). There was a dose-response relationship between STAI score and risk of death or MI. There was no association between self-reported anxiety and atherosclerotic progression of grafts.

CONCLUSIONS

Anxiety symptoms are associated with increased risk of death or MI among patients with saphenous vein grafts, but this risk does not appear to be mediated by more extensive atherosclerotic progression.

Depressive symptoms and the risk of atherosclerotic progression among patients with coronary artery bypass grafts

BACKGROUND

Depressive symptoms have been associated with increased risk of coronary artery disease and poor prognosis among patients with existing coronary artery disease, but whether depressive symptoms specifically influence atherosclerotic progression among such patients is uncertain.

METHODS AND RESULTS

The Post-CABG Trial randomized patients with a history of coronary bypass graft surgery to either an aggressive or a moderate lipid-lowering strategy and to either warfarin or placebo. Coronary angiography was conducted at enrollment and after a median follow-up of 4.2 years. Depressive symptoms were assessed at enrollment with the Centers for Epidemiologic Studies Depression scale (CES-D) in 1319 patients with 2496 grafts. In models that adjusted for age, gender, race, treatment assignment, and years since coronary bypass graft surgery, a CES-D score > or =16 was positively associated with risk of substantial graft disease progression (OR 1.50, 95% CI 1.08 to 2.10, P=0.02) and marginally associated with a 0.11-mm (95% CI -0.22 to 0.01 mm, P=0.07) decrease in minimum lumen diameter, but not with risk of graft occlusion (P=0.30). Additional adjustment for past medical history, blood pressure, and renal function did not materially alter these results. This association was virtually absent among participants randomly assigned to aggressive lipid-lowering therapy.

CONCLUSIONS

These findings suggest that depressive symptoms are associated with a higher risk of atherosclerotic progression among patients with saphenous vein grafts and that aggressive lipid lowering can minimize this increased risk. Whether depressive symptoms increase progression in other types of coronary atherosclerosis and whether aggressive lipid lowering attenuates such progression will require additional study.

To drink or not to drink? That is the question

Numerous studies have used a J-shaped or U-shaped curve to describe the relationship between alcohol use and total mortality. The nadir of the curves based on recent meta-analysis suggested optimal benefit at approximately half a drink per day. Fewer than 4 drinks per day in men and fewer than 2 per day in women appeared to confer benefit. Reductions in cardiovascular death and nonfatal myocardial infarction were also associated with light to moderate alcohol intake. Although some studies suggested that wine had an advantage over other types of alcoholic beverages, other studies suggested that the type of drink was not important. Heavy drinking was associated with an increase in mortality, hypertension, alcoholic cardiomyopathy, cancer, and cerebrovascular events, including cerebrovascular hemorrhage. Paradoxically, light-to-moderate alcohol use actually reduced the development of heart failure and did not appear to exacerbate it in most patients who had underlying heart failure. Numerous mechanisms have been proposed to explain the benefit that light-to-moderate alcohol intake has on the heart, including an increase of high-density lipoprotein cholesterol, reduction in plasma viscosity and fibrinogen concentration, increase in fibrinolysis, decrease in platelet aggregation, improvement in endothelial function, reduction of inflammation, and promotion of antioxidant effects. Controversy exists on whether alcohol has a direct cardioprotective effect on ischemic myocardium. Studies from our laboratory do not support the concept that alcohol has a direct cardioprotective effect on ischemic/reperfused myocardium. Perhaps the time has come for a prospectively randomized trial to determine whether 1 drink per day (or perhaps 1 drink every other day) reduces mortality and major cardiovascular events.