Effect of statins on atrial fibrillation after cardiac surgery: A duration- and dose-response meta-analysis

Preoperative statin therapy for adults undergoing cardiac surgery

BACKGROUND

Despite significant advances in surgical techniques and perioperative care, people undertaking cardiac surgery due to cardiovascular disease are more prone to the development of postoperative adverse events. Statins (5-hydroxy-3-methylglutaryl-co-enzyme A (HMG-CoA) reductase inhibitors) are well-known for their anti-inflammatory and antioxidant effects and are established for primary and secondary prevention of coronary artery disease. In addition, statins are thought to have clinical benefits in perioperative outcomes in people undergoing cardiac surgery. This review is an update of a review that was first published in 2012 and updated in 2015.

OBJECTIVES

To evaluate the benefits and harms of preoperative statin therapy in adults undergoing cardiac surgery compared to standard of care or placebo.

SEARCH METHODS

We performed a search of the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 9, 2023), Ovid MEDLINE (1980 to 14 September 2023), and Ovid Embase (1980 to 2023 (week 36)). We applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing any statin treatment before cardiac surgery, for any given duration and dose, versus no preoperative statin therapy (standard of care) or placebo. We excluded trials without a registered trial protocol and trials without approval by an institutional ethics committee.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. Primary outcomes were short-term mortality and major adverse cardiovascular events. Secondary outcomes were myocardial infarction, atrial fibrillation, stroke, renal failure, length of intensive care unit (ICU) stay, length of hospital stay and adverse effects related to statin therapy. We reported effect measures as risk ratios (RRs) or mean differences (MDs) with corresponding 95% confidence intervals (CIs). We used the RoB 1 tool to assess the risk of bias in included trials, and GRADE to assess the certainty of the evidence.

MAIN RESULTS

We identified eight RCTs (five new to this review) including 5592 participants. Pooled analysis showed that statin treatment before surgery may result in little to no difference in the risk of postoperative short-term mortality (RR 1.36, 95% CI 0.72 to 2.59; I2 = 0%; 6 RCTs, 5260 participants; low-certainty evidence; note 2 RCTs reported 0 events in both groups so RR calculated from 4 RCTs with 5143 participants). We are very uncertain about the effect of statins on major adverse cardiovascular events (RR 0.93, 95% CI 0.77 to 1.13; 1 RCT, 2406 participants; very low-certainty evidence). Statins probably result in little to no difference in myocardial infarction (RR 0.88, 95% CI 0.73 to 1.06; I2 = 0%; 5 RCTs, 4645 participants; moderate-certainty evidence), may result in little to no difference in atrial fibrillation (RR 0.87, 95% CI 0.72 to 1.05; I2 = 60%; 8 RCTs, 5592 participants; low-certainty evidence), and may result in little to no difference in stroke (RR 1.47, 95% CI 0.90 to 2.40; I2 = 0%; 4 RCTs, 5143 participants; low-certainty evidence). We are very uncertain about the effect of statins on renal failure (RR 1.04, 95% CI 0.80 to 1.34; I2 = 57%; 4 RCTs, 4728 participants; very low-certainty evidence). Additionally, statins probably result in little to no difference in length of ICU stay (MD 1.40 hours, 95% CI -1.62 to 4.41; I2 = 43%; 3 RCTs, 4528 participants; moderate-certainty evidence) and overall hospital stay (MD -0.31 days, 95% CI -0.64 to 0.03; I2 = 84%; 5 RCTs, 4788 participants; moderate-certainty evidence). No study had any individual risk of bias domain classified as high. However, two studies were at high risk of bias overall given the classification of unclear risk of bias in three domains.

AUTHORS' CONCLUSIONS

In this updated Cochrane review, we found no evidence that statin use in the perioperative period of elective cardiac surgery was associated with any clinical benefit or worsening, when compared with placebo or standard of care. Compared with placebo or standard of care, statin use probably results in little to no difference in MIs, length of ICU stay and overall hospital stay; and may make little to no difference to mortality, atrial fibrillation and stroke. We are very uncertain about the effects of statins on major harmful cardiac events and renal failure. The certainty of the evidence validating this finding varied from moderate to very low, depending on the outcome. Future trials should focus on assessing the impact of statin therapy on mortality and major adverse cardiovascular events.

Effect of preoperative moderate-dose statin and duration on acute kidney injury after cardiac surgery: a retrospective cohort study

BACKGROUND

The impact of preoperative statin use on postoperative acute kidney injury (AKI) is uncertain. We aimed to examine the association of statin therapy before cardiac surgery with postoperative AKI.

METHODS

The retrospective cohort study consisted of 1581 patients undergoing cardiac surgery. Postoperative AKI were identified by the modified KDIGO definition. Propensity-score matching was employed to control for selection bias, and logistic regression was used to control for confounders. Subgroup and interaction analyses were performed to evaluate the robustness of the findings.

RESULTS

The overall incidence of postoperative AKI and severe AKI were 42.19% and 12.27%, respectively. Preoperative moderate-dose statin was significantly associated with a reduced incidence of postoperative AKI (28.9% vs 43.0%, OR (95%CI): 0.54 (0.38, 0.77), p < 0.001) and severe AKI (6.9% vs 13.7%, OR (95%CI): 0.46 (0.26, 0.83), p = 0.009). The beneficial effect on postoperative AKI persisted after adjusting for major confounding factors (OR (95%CI): 0.47 (0.34, 0.66)). Decreased risk of postoperative AKI was observed in patients with preoperative statin duration of 7 ∼ 14 days (OR (95%CI): 0.41 (0.25, 0.65)) and over 14 days (OR (95%CI): 0.43 (0.28, 0.65)), but not in those with preoperative statin duration of <7 days. Similar favorable effects were noted in most subgroup patients, except for those with high-risk factors such as diabetes mellitus, previous congestive cardiac failure, arrhythmia, preoperative ACEI/ARB, aortic cross-clamping or IABP.

CONCLUSION

Preoperative moderate-dose statin was significantly related to a decreased risk of postoperative AKI, especially in patients who received statins for a longer duration. Further large-scale multicenter randomized controlled trials are needed to ascertain the impact of statin dose, duration, and timing on postoperative AKI in cardiac surgery patients.

Atrial fibrillation: primary prevention, secondary prevention, and prevention of thromboembolic complications: part 1

Atrial fibrillation (AF), is the most common sustained cardiac arrhythmia. It was once thought to be benign as long as the ventricular rate was controlled, however, AF is associated with significant cardiac morbidity and mortality. Increasing life expectancy driven by improved health care and decreased fertility rates has, in most of the world, resulted in the population aged ≥65 years growing more rapidly than the overall population. As the population ages, projections suggest that the burden of AF may increase more than 60% by 2050. Although considerable progress has been made in the treatment and management of AF, primary prevention, secondary prevention, and prevention of thromboembolic complications remain a work in progress. This narrative review was facilitated by a MEDLINE search to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1950 and 2021. Atrial fibrillation was searched via the terms primary prevention, hyperthyroidism, Wolff-Parkinson-White syndrome, catheter ablation, surgical ablation, hybrid ablation, stroke prevention, anticoagulation, left atrial occlusion and atrial excision. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. In these two manuscripts, we discuss the current strategies available to prevent AF, then compare noninvasive and invasive treatment strategies to diminish AF recurrence. In addition, we examine the pharmacological, percutaneous device and surgical approaches to prevent stroke as well as other types of thromboembolic events.

Long-Term Preoperative Atorvastatin or Rosuvastatin Use in Adult Patients before CABG Does Not Increase Incidence of Postoperative Acute Kidney Injury: A Propensity Score-Matched Analysis

Background: Acute kidney injury (AKI) is among the expected complications of cardiac surgery. Statins with pleiotropic anti-inflammatory and antioxidant effects may be effective in the prevention of AKI. However, the results of studies on the efficacy and safety of statins are varied and require further study. Methods: We conducted a retrospective cohort study to evaluate long-term preoperative intake of atorvastatin and rosuvastatin on the incidence of AKI, based on the “Kidney Disease: Improving Global Outcomes” (KDIGO) criteria in the early postoperative period after coronary artery bypass graft surgery (CABG). We performed propensity score matching to compare the findings in our study groups. The incidence of AKI was assessed on day 2 and day 4 after the surgery. Results: The analysis included 958 patients after CABG. After 1:1 individual matching, based on propensity score, the incidence of AKI was comparable both on day 2 after the surgery (7.4%) between the atorvastatin group and rosuvastatin group (6.5%) (OR: 1.182; 95%Cl 0.411–3.397; p = 0.794), and on postoperative day 4 between the atorvastatin group (3.7%) and the rosuvastatin group (4.6%) (OR: 0.723, 95%Cl 0.187–2.792; p = 0.739). Additionally, there were no statistically significant differences in terms of incidence of AKI after 1:1 individual matching, based on propensity score, between the rosuvastatin group and the control group both on postoperative day 2 (OR: 0.692; 95%Cl 0.252–1.899; p = 0.611) and day 4 (OR: 1.245; 95%Cl 0.525–2.953; p = 0.619); as well as between the atorvastatin group and the control group both on postoperative day 2 (OR: 0.549; 95%Cl 0.208–1.453; p = 0.240) and day 4 (OR: 0.580; 95%Cl 0.135–2.501; p = 0.497). Conclusion: Long-term statin use before CABG did not increase the incidence of postoperative AKI. Further, we revealed no difference in the incidence of post-CABG AKI between the atorvastatin and rosuvastatin groups.

Posterior pericardiotomy to prevent new-onset atrial fibrillation after coronary artery bypass grafting: a systematic review and meta-analysis of 10 randomized controlled trials

BACKGROUND

Atrial fibrillation (AF) is associated with adverse events after cardiac surgery. Multiple studies have reported that posterior pericardiotomy (PP) may be effective for preventing AF after coronary artery bypass grafting (CABG), but some conflicting results have been reported and the quality of evidence from previous meta-analyses has been limited. The present study aimed to systematically evaluate the safety and efficacy of PP for preventing AF after CABG in adults.

METHODS

We conducted a quantitative meta-analysis of randomized controlled trials (RCTs) published before May 31, 2021. The primary outcome was AF after CABG under cardiopulmonary bypass. Secondary outcomes included early pericardial effusion, late pericardial effusion, pericardial tamponade, pleural effusion, length of hospital stay, length of intensive care unit (ICU) stay, pulmonary complications, intra-aortic balloon pump use, revision surgery for bleeding, and mortality.

RESULTS

Ten RCTs with 1829 patients (910 in the PP group and 919 in the control group) were included in the current meta-analysis. The incidence of AF was 10.3% (94/910) in the PP group and 25.7% (236/919) in the control group. A random-effects model indicated that incidence of AF after CABG significantly lower in the PP group than in the control group (risk ratio = 0.45, 95% confidence interval 0.29-0.64, P < 0.0001). PP also effectively reduced the post-CABG occurrence of early pericardial effusion (RR = 0.28, 95% CI 0.15-0.50; P < 0.05), late pericardial effusion (RR = 0.06, 95% CI 0.02-0.16; P < 0.05), and pericardial tamponade (RR = 0.08, 95% CI 0.02-0.33; P < 0.05) as well as the length of ICU stay (weighted mean difference [WMD] = 0.91,95% CI 0.57-1.24; P < 0.05), while increasing the occurrence pleural effusion (RR = 1.51, 95% CI 1.19-1.92; P < 0.05). No significant differences length of hospital stay (WMD =  - 0.45, 95% CI - 2.44 to 1.54, P = 0.66), pulmonary complications (RR = 0.99, 95% CI 0.71-1.39, P = 0.97), revision surgery for bleeding (RR = 0.84, 95% CI 0.43-1.63, P = 0.60), use of IABP (RR = 1, 95% CI 0.61-1.65, P = 1.0), or death (RR = 0.45, 95% CI 0.07-3.03, P = 0.41) were observed between the PP and control groups.

CONCLUSIONS

PP may be a safe, effective, and economical method for preventing AF after CABG in adult patients.

Update on the efficacy of statins in primary and secondary prevention of atrial fibrillation

Atrial fibrillation is the most common arrhythmia in adults and its prevalence is growing rapidly. It has been shown that AF is associated with increased risk of heart failure, ischemic and hemorrhagic stroke, and mortality. Hence, there is growing interest among researchers in seeking preventive and therapeutic interventions regarding AF. In recent decades, it has been suggested that statins may decrease the incidence of AF and may also decrease its recurrence after cardioversion and catheter ablation. These effects are thought to be mediated by different mechanisms such as modulating inflammation, altering the properties of transmembrane ion channels, interfering with activation of matrix metalloproteinases, and acting on endothelial function. In this article, we review and update current knowledge about the role of statins in primary and secondary prevention of AF in general and specific populations.

Update on the efficacy of statins in primary and secondary prevention of atrial fibrillation

Atrial fibrillation is the most common arrhythmia in adults and its prevalence is growing rapidly. It has been shown that AF is associated with increased risk of heart failure, ischemic and hemorrhagic stroke, and mortality. Hence, there is growing interest among researchers in seeking preventive and therapeutic interventions regarding AF. In recent decades, it has been suggested that statins may decrease the incidence of AF and may also decrease its recurrence after cardioversion and catheter ablation. These effects are thought to be mediated by different mechanisms such as modulating inflammation, altering the properties of transmembrane ion channels, interfering with activation of matrix metalloproteinases, and acting on endothelial function. In this article, we review and update current knowledge about the role of statins in primary and secondary prevention of AF in general and specific populations.

Statin Therapy in Post-Operative Atrial Fibrillation: Focus on the Anti-Inflammatory Effects

BACKGROUND

Atrial fibrillation (AF) occurring after cardiac surgery, post-operative AF (POAF), is a serious and common complication of this treatment. POAF may be life-threatening and the available preventive strategies are insufficient or are associated with significantly increased risk of adverse effects, especially in long-term use. Therefore, more appropriate treatment strategies are needed.

METHODS

In this paper, the efficacy, safety, and other aspects of using statins in the prevention of POAF focusing on their anti-inflammatory effects are reviewed.

RESULTS

Recent studies have suggested that inflammation has a significant role in POAF, from the first AF episode to its serious complications including stroke and peripheral embolism. On the other hand, statins, the most widely used medications in cardiovascular patients, have pleiotropic effects, including anti-inflammatory properties. Therefore, they may potentially be effective in POAF prevention. Statins, especially atorvastatin, appear to be an effective option for primary prevention of POAF, especially in patients who had coronary artery bypass grafting (CABG), a cardiac surgery treatment associated with inflammation in the heart muscle. However, several large studies, particularly with rosuvastatin, did not confirm the beneficial effect of statins on POAF. One large clinical trial reported higher risk of acute kidney injury (AKI) following high-dose rosuvastatin in Chinese population. In this study, rosuvastatin reduced the level of C-reactive protein (CRP) but did not reduce the rate of POAF.

CONCLUSION

Further studies are required to find the most effective statin regimen for POAF prevention with the least safety concern and the highest health benefits.

Upstream Therapy for Atrial Fibrillation Prevention: The Role of Sacubitril/Valsartan

The therapy or prevention of atrial fibrillation (AF) is defined as upstream therapy when conducted with the use of drugs, e.g., angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor antagonists, statins, and omega-3 fatty acids, not included in the classes of antiarrhythmic drugs recognized by the Vaughan Williams classification. In our review, we illustrate the rational bases of upstream AF therapy, which encompasses drugs having the property to reduce hemodynamic congestion and cardiac overload, as in the case of ACEIs or angiotensin receptor blockers, as well as drugs able to prevent atrial fibrosis or reduce oxidative stress, such as statins or omega-3 fatty acids, respectively. In this review, randomized controlled trials (RCTs) conducted with the abovementioned drugs are examined. Really, these RCTs have generated mixed results. In the context of the prevention and therapy of AF, our experience is then presented, relating to a patient with heart failure and reduced left ventricular ejection fraction, with a history of relapsing episodes of paroxysmal AF. In this patient, administration of sacubitril/valsartan at appropriate doses allowed recovery of the sinus rhythm. Therefore this case testifies how the upstream therapy of AF might have good results when conducted with sacubitril/valsartan. Thus, RCTs with adequate statistical power are warranted in order to confirm the preliminary encouraging result of our case report, and validate a useful role of sacubitril/valsartan as an upstream therapy of AF.

Factors Modifying the Risk of Atrial Fibrillation Associated With Atrial Premature Complexes in Patients With Hypertension

Patients with hypertension who develop atrial premature complexes (APCs) are at a particularly high risk for atrial fibrillation (AF). We sought to identify medications and modifiable risk factors that could reduce the risk of AF imposed by presence of APCs in such a high risk group. This analysis included 4,331 participants with treated hypertension from the Reasons for Geographic and Racial Differences in Stroke study who were free of AF and cardiovascular disease at the time of enrollment (2003-2007). APCs were detected in 8.2% (n = 356) of the participants at baseline. During a median follow-up of 9.4 years, 9.9% (n = 429) of the participants developed AF. Participants with APCs, compared with those without, were more than twice as likely to develop AF (Odds ratio [95% confidence interval]: 2.36[1.75, 3.19]). This association was significantly weaker in statin users than nonusers (Odds ratio [95% confidence interval]:1.42[0.81,2.48] vs 3.01[2.11,4.32], respectively; interaction p-value = 0.02), and in angiotensin-II receptor blocker users than nonusers (Odds ratio [95% confidence interval]:1.31[0.66,2.61] vs 2.78[1.99,3.89], respectively; interaction p-value = 0.05). Borderline weaker associations between APCs and AF were also observed in alpha-blocker users than nonusers, nondiabetics than diabetics, and in those with systolic blood pressure level 130 to 139 mm Hg compared with those with other systolic blood pressure levels. No significant effect modifications were observed by use of other medications or by presence of other cardiovascular risk factors. In conclusion, the significant AF risk associated with APCs in patients with hypertension could potentially be reduced by treatment with angiotensin-II receptor blockers and statins along with lowering blood pressure and management of diabetes.

The Role of Statins in the Management of Patients Undergoing Coronary Artery Bypass Grafting

Each year, a large number of patients undergo coronary artery bypass grafting surgery (CABG) worldwide. Accumulating evidence suggests that the preoperative administration of statins might be useful in preventing adverse events after CABG. In the present review, we discuss the role of statins in the perioperative management of patients undergoing CABG. Preoperative administration of statins in these patients substantially reduces the risk of postoperative atrial fibrillation and shortens hospital and intensive care unit (ICU) stay. Atorvastatin appears to be more effective, particularly when administered at high doses. Given these benefits and the safety of statins, their administration should be considered in patients undergoing CABG, even though the statins do not appear to affect the incidence of cardiovascular events and overall mortality perioperatively.

Pharmacological interventions for preventing post-operative atrial fibrillation in patients undergoing cardiac surgery: a network meta-analysis protocol

INTRODUCTION

Postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery, and randomised clinical trials (RCTs) and systematic reviews have been conducted to compare and evaluate different pharmacological interventions for preventing POAF. This study aimed to explore the effect of different pharmacological interventions for prophylaxis against POAF after cardiac surgery using network meta-analysis (NMA).

METHODS AND ANALYSIS

A systematic search will be performed in PubMed, EMBASE and the Cochrane Library to identify RCTs, systematic reviews, meta-analyses or NMA of different pharmacological interventions for POAF. We will evaluate the risk of bias of the included RCTs according to the Cochrane Handbook V.5.1.0, and use GRADE to assess the quality of evidence. Standard pairwise meta-analysis, trial sequential analysis and Bayesian network meta-analysis will be used to compare the efficacy of different pharmacological interventions.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is a meta-analysis based on published studies. The results of this NMA and trial sequential analysis will be submitted to a peer-reviewed journal for publication.

PROTOCOL REGISTRATION NUMBER

CRD42017067492.

Pharmacologic Prevention of Incident Atrial Fibrillation: Long-Term Results From the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial)

BACKGROUND

Although atrial fibrillation (AF) guidelines indicate that pharmacological blockade of the renin-angiotensin system may be considered for primary AF prevention in hypertensive patients, previous studies have yielded conflicting results. We sought to determine whether randomization to lisinopril reduces incident AF or atrial flutter (AFL) compared with chlorthalidone in a large clinical trial cohort with extended post-trial surveillance.

METHODS AND RESULTS

We performed a secondary analysis of the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial), a randomized, double-blind, active-controlled clinical trial that enrolled hypertensive individuals ≥55 years of age with at least one other cardiovascular risk factor. Participants were randomly assigned to receive amlodipine, lisinopril, or chlorthalidone. Individuals with elevated fasting low-density lipoprotein cholesterol levels were also randomized to pravastatin versus usual care. The primary outcome was the development of either AF or AFL as diagnosed by serial study ECGs or by Medicare claims data. Among 14 837 participants without prevalent AF or AFL, 2514 developed AF/AFL during a mean 7.5±3.2 years of follow-up. Compared with chlorthalidone, randomization to either lisinopril (hazard ratio, 1.04; 95% confidence interval, 0.94-1.15; P=0.46) or amlodipine (hazard ratio, 0.93; 95% confidence interval, 0.84-1.03; P=0.16) was not associated with a significant reduction in incident AF/AFL.

CONCLUSIONS

Compared with chlorthalidone, treatment with lisinopril is not associated with a meaningful reduction in incident AF or AFL among older adults with a history of hypertension.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000542.

A Population-Based Cohort Study on the Drug-Specific Effect of Statins on Sepsis Outcome

BACKGROUND

Whether statin treatment, proved by recent experimental studies to have an antimicrobial activity, exerts a drug- or a class-specific effect in sepsis remains unknown.

METHODS

Short-term mortality in patients with sepsis was analyzed using data from the National Health Insurance Research Database. Use of statins was defined as the cumulative use of a specific statin (atorvastatin, simvastatin, or rosuvastatin) for > 30 days prior to the index sepsis admission. We determined the association between statin and sepsis outcome by multivariate-adjusted Cox models and propensity score (PS)-matched analysis, using a 1:1:1 PS matching technique.

RESULTS

A total of 52,737 patients with sepsis fulfilled the inclusion criteria, of which 1,855 were prescribed atorvastatin, 916 were prescribed simvastatin, and 732 were prescribed rosuvastatin. Compared with nonusers, simvastatin (hazard ratio [HR], 0.72; 95% CI, 0.58-0.90) and atorvastatin (HR, 0.78; 95% CI, 0.68-0.90) were associated with an improved 30-day survival, whereas rosuvastatin was not (HR, 0.87; 95% CI, 0.73-1.04). Using rosuvastatin as the reference, atorvastatin (HR, 0.79; 95% CI, 0.64-0.99) and simvastatin (HR, 0.77; 95% CI, 0.59-0.99) had superior effectiveness in preventing mortality.

CONCLUSIONS

Compatible with in vitro experimental findings, our results suggest that the drug-specific effect of statins on sepsis is not correlated to their lipid-lowering potency.

Does short preoperative statin therapy prevent infectious complications in adults undergoing cardiac or non-cardiac surgery? A meta-analysis of 5 randomized placebo-controlled trials

Objectives:

To evaluate the effect of preoperative statin therapy on the incidence of postoperative infection.

Methods:

This systematic review of the literature was carried out in August 2015. Studies were retrieved via PubMed, Embase, and the Cochrane Library (1980 to 2015), and the reference files were limited to English-language articles. We used a standardized protocol, and a meta-analysis was performed for data abstraction.

Results:

Five studies comprising 1,362 patients qualified for the analysis. The incidence of postoperative infections in the statin group (1.1%) was not significantly lower than that in the placebo group (2.4%), with a risk ratio (RR) of 0.56 (95% confidence interval [CI] 0.24-1.33, p=0.19). Patients of 3 studies underwent cardiac surgery. The aggregated results of these studies failed to show significant differences in postoperative infection when a fixed effects model was used (RR: 0.39; 95% CI: 0.08-1.97, p=0.26].

Conclusions:

We failed to find sufficient evidence to support the association between statin use and postoperative infectious complications. The absence of any evidence for a beneficial effect in available randomized trials reduces the likelihood of a causal effect as reported in observational studies.

The burden of proof: The current state of atrial fibrillation prevention and treatment trials

Atrial fibrillation (AF) is an age-related arrhythmia of enormous socioeconomic significance. In recent years, our understanding of the basic mechanisms that initiate and perpetuate AF has evolved rapidly, catheter ablation of AF has progressed from concept to reality, and recent studies suggest lifestyle modification may help prevent AF recurrence. Emerging developments in genetics, imaging, and informatics also present new opportunities for personalized care. However, considerable challenges remain. These include a paucity of studies examining AF prevention, modest efficacy of existing antiarrhythmic therapies, diverse ablation technologies and practice, and limited evidence to guide management of high-risk patients with multiple comorbidities. Studies examining the long-term effects of AF catheter ablation on morbidity and mortality outcomes are not yet completed. In many ways, further progress in the field is heavily contingent on the feasibility, capacity, and efficiency of clinical trials to incorporate the rapidly evolving knowledge base and to provide substantive evidence for novel AF therapeutic strategies. This review outlines the current state of AF prevention and treatment trials, including the foreseeable challenges, as discussed by a unique forum of clinical trialists, scientists, and regulatory representatives in a session endorsed by the Heart Rhythm Society at the 12th Global CardioVascular Clinical Trialists Forum in Washington, DC, December 3-5, 2015.

Atrial fibrillation after cardiac surgery: Prevention and management: The Australasian experience

Background

Atrial fibrillation (AF) after cardiac surgery is a major health problem that is associated with a significant financial burden. This paper aims to highlight this problem and review the current guidelines in the prevention and management of AF after cardiac surgery, providing our experience in the Australasian centers.

Methods

We conducted a literature review using mainly PubMed to compare the current practice with the available evidence. EMBASE and Cochrane library were also searched. We concurrently developed an online questionnaire to collect data from other Australasian centers regarding their approach to this problem.

Results

We identified 194 studies that were considered relevant to our research. We did not find any formal protocols published in the literature. From our Australasian experience; seven centers (58%) had a protocol for AF prophylaxis. The protocols included electrolytes replacement, use of amiodarone and/or β-blockers. Other strategies were occasionally used but were not part of a structured protocol.

Conclusion

The development of an integrated medical and surgical protocol for the prophylaxis of AF after cardiac surgery is an important aspect for the care of postoperative cardiac patients. Considerations of prophylactic strategies other than those routinely used should be included in the protocol. This area should receive considerable attention in order to reduce the postoperative complications and health costs.

Defining the role of perioperative statin treatment in patients after cardiac surgery: A meta-analysis and systematic review of 20 randomized controlled trials

BACKGROUND

Although statin use has been indicated to prevent atrial fibrillation in previous observational and experimental trials, the issue remains inadequately and insufficiently explored. We therefore performed this meta-analysis to evaluate the effects of perioperative statin therapy on complications and short-term prognosis following cardiac surgery.

METHODS

A search of the PubMed, EMBASE and the Cochrane database of controlled trials was performed from inception to June 2016 to identify relevant randomized controlled trials (RCTs). The primary endpoints included postoperative atrial fibrillation, acute kidney injury and all-cause mortality.

RESULTS

Twenty studies involving 4338 patients were included in the meta-analysis. Among the patients who underwent cardiac surgery, perioperative statin therapy was significantly associated with a decreased risk of postoperative atrial fibrillation (OR: 0.50; P=0.0004), particularly in the subgroup of patients who used atorvastatin and those who underwent isolated coronary artery bypass grafting (CABG) surgery. Moreover, perioperative statin use significantly decreased the length of hospital stay (weighted mean difference (WMD): -0.43; P=0.002). However, no reductions were observed in acute kidney injury, myocardial infarction, postoperative serum creatinine concentration or the length of intensive care unit (ICU) stay.

CONCLUSIONS

Perioperative statin therapy might be promising for the prevention of postoperative atrial fibrillation following cardiac surgery, especially for patients undergoing isolated CABG surgery or atorvastatin administration. Additionally, statin use can decrease the length of the hospital stay.

Recent Advances in the Pharmacological Management of Atrial Fibrillation

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia that leads to hospitalizations for complications and adverse events each year. Despite significant improvement in our therapeutic approaches in the past decade, management of AF remains a difficult task. Novel therapies have failed to terminate AF and prevent its recurrence, and patients with AF continue to have thromboembolic complications. With the increasingly aging population and associated conditions, the prevalence of AF is expected to progressively increase, becoming a public health problem. Most patients with AF have multiple comorbidities and are of advanced age, making long-term anticoagulation challenging. This article provides an overview of the current pharmacological therapies for the management of AF, with particular emphasis on the emerging agents.

Efficacy of Different Perioperative Statin Regimens on Protection Against Post-Coronary Artery Bypass Grafting Major Adverse Cardiac and Cerebral Events

OBJECTIVES

Comparing different perioperative statin regimens for the prevention of post-coronary artery bypass grafting adverse events.

DESIGN

A randomized, prospective study.

SETTING

Cardiothoracic surgical units in a government hospital.

PARTICIPANTS

The study comprised 94 patients scheduled for elective, isolated on- or off- pump coronary artery bypass grafting.

INTERVENTIONS

Patients were assigned randomly to 1 of the following 3 treatment groups: group I (80 mg of atorvastatin/day for 2 days preoperatively), group II (40 mg of atorvastatin/day for 5-9 days preoperatively), or group III (80 mg of atorvastatin/day for 5-9 days preoperatively). The same preoperative doses were restarted postoperatively and continued for 1 month.

MEASUREMENTS AND MAIN RESULTS

Cardiac troponin I, creatine kinase, and C-reactive protein (CRP) levels were assayed preoperatively; at 8, 24, and 48 hours postoperatively; and at discharge. CRP levels at 24 hours (p = 0.045) and 48 hours (p = 0.009) were significantly lower in group III compared with the other 2 groups. However, troponin I levels at 8 hours (p = 0.011) and 48 hours (p = 0.025) after surgery were significantly lower in group II compared with group III. The incidence of postoperative major adverse cardiac and cerebrovascular events was assessed, and there was no significant difference among the 3 groups.

CONCLUSION

The 3 regimens did not result in any significant difference in outcomes, but only simple trends. The higher-dose regimen resulted in a significant reduction in the CRP level. Thus, more studies are needed to confirm the benefit of higher-dose statins for the protection from post-coronary artery bypass grafting adverse events.

WITHDRAWN: Preoperative statin therapy for patients undergoing cardiac surgery

This review has been withdrawn as authors are unable to complete the updating process.

The editorial group responsible for this previously published document have withdrawn it from publication.

Perioperative Rosuvastatin in Cardiac Surgery

BACKGROUND

Complications after cardiac surgery are common and lead to substantial increases in morbidity and mortality. Meta-analyses of small randomized trials have suggested that perioperative statin therapy can prevent some of these complications.

METHODS

We randomly assigned 1922 patients in sinus rhythm who were scheduled for elective cardiac surgery to receive perioperative rosuvastatin (at a dose of 20 mg daily) or placebo. The primary outcomes were postoperative atrial fibrillation within 5 days after surgery, as assessed by Holter electrocardiographic monitoring, and myocardial injury within 120 hours after surgery, as assessed by serial measurements of the cardiac troponin I concentration. Secondary outcomes included major in-hospital adverse events, duration of stay in the hospital and intensive care unit, left ventricular and renal function, and blood biomarkers.

RESULTS

The concentrations of low-density lipoprotein cholesterol and C-reactive protein after surgery were lower in patients assigned to rosuvastatin than in those assigned to placebo (P<0.001). However, the rate of postoperative atrial fibrillation did not differ significantly between the rosuvastatin group and the placebo group (21.1% and 20.5%, respectively; odds ratio 1.04; 95% confidence interval [CI], 0.84 to 1.30; P=0.72), nor did the area under the troponin I-release curve (102 ng×hour per milliliter and 100 ng×hour per milliliter, respectively; between-group difference, 1%; 95% CI, -9 to 13; P=0.80). Subgroup analyses did not indicate benefit in any category of patient. Rosuvastatin therapy did not result in beneficial effects on any of the secondary outcomes but was associated with a significant absolute (±SE) excess of 5.4±1.9 percentage points in the rate of postoperative acute kidney injury (P=0.005).

CONCLUSIONS

In this trial, perioperative statin therapy did not prevent postoperative atrial fibrillation or perioperative myocardial damage in patients undergoing elective cardiac surgery. Acute kidney injury was more common with rosuvastatin. (Funded by the British Heart Foundation and others; STICS ClinicalTrials.gov number, NCT01573143.).

Statin therapy in the primary prevention of early atrial fibrillation after coronary artery bypass grafting

OBJECTIVE

Assessment of the role of statin therapy in the prevention of postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) in patients without prior atrial fibrillation.

METHODS

A retrospective analysis of 206 patients, aged 57.2±7.9 years (mean±SD), who underwent isolated CABG is carried out. All patients are divided into two groups. The first group (nSt-patients) includes the patients who did not receive statin therapy prior to CABG (n=82). The second group (St-patients) includes the patients who received statin therapy prior to CABG (n=124). Both groups received the statin therapy from the first day after CABG. The risk of occurrence of POAF is evaluated using the Cox-regression model.

RESULTS

The rate of POAF was 25.6% in nSt-patients and 6.5% in St-patients (P=0.020). On the 4th day after CABG, white blood cells (WBC) count was 11.0 (9.0, 13.0)×10⁹/mL (medians with inter-quartile ranges) in nSt-patients and 9.0 (7.6, 10.2)×10⁹/mL in St-patients (P<0.001). The peak WBC numbers occurred on the day of POAF onset. The Cox-regression analysis shows that only two factors (statin therapy and number of grafts) had significant influence on the POAF onset. Odds ratio of POAF event prediction by statin therapy was 0.20 (95%CI: 0.08-0.51), P<0.001. Each subsequent graft increased the risk of POAF in 2.1 times.

CONCLUSION

Statin therapy carried out prior to the CABG is an effective approach to primary prevention of POAF in early postoperative period. Statin therapy after CABG in nSt-patients does not give prophylactic effect observed in St-patients.

Does the use of statins improve outcomes in coronary artery bypass graft surgery?

Statins (3-hydroxy-3-methylglutaryl CoA reductase inhibitors) are one of the most frequently prescribed medications throughout the world with beneficial effects that extend beyond their lipid-lowering activity. It has been suggested that statins may offer a simple and cost-effective strategy to reduce some of the complications that occur in association with coronary artery bypass graft (CABG) surgery. Limited existing randomized trial evidence in the setting of cardiac surgery suggests that statins may reduce the incidence of postoperative atrial fibrillation. However, any effect of statins on other outcomes is less clear. The clinical significance of specific statin agent and dose, acute statin withdrawal and the potential benefits associated with statin reloading remain important yet currently unresolved issues. Despite limited high-quality evidence, class I recommendations have been made that all patients undergoing coronary artery bypass graft surgery should receive statin therapy unless contraindicated.

Pharmacological strategies for prevention of postoperative atrial fibrillation

Atrial fibrillation (AF) complicating cardiac surgery continues to be a major problem that increases the postoperative risk of stroke, myocardial infarction, heart failure and costs and can affect long-term survival. The incidence of AF after surgery has not significantly changed over the last two decades, despite improvement in medical and surgical techniques. The mechanism and pathophysiology underlying postoperative AF (PoAF) is incompletely understood and results from a combination of acute and chronic factors, superimposed on an underlying abnormal atrial substrate with increased interstitial fibrosis. Several anti-arrhythmic and non-anti-arrhythmic medications have been used for the prevention of PoAF, but the effectiveness of these strategies has been limited due to a poor understanding of the basis for the increased susceptibility of the atria to AF in the postoperative setting. In this review, we summarize the pathophysiology underlying the development of PoAF and evidence behind pharmacological approaches used for its prevention in the postoperative setting.

Preoperative statin therapy for patients undergoing cardiac surgery

BACKGROUND

Patients referred to cardiac surgery for cardiovascular disease are at significant risk for the development of major postoperative adverse events despite significant advances in surgical techniques and perioperative care. Statins (5-hydroxy-3-methylglutaryl-co-enzyme A (HMG-CoA) reductase inhibitors) have gained a pivotal role in the primary and secondary prevention of coronary artery disease and are thought to improve perioperative outcomes in patients undergoing cardiac surgery. This review is an updated version of a review that was first published in 2012.

OBJECTIVES

To determine the effectiveness of preoperative statin therapy in patients undergoing cardiac surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11), MEDLINE (1950 to November 2013 Week 3), EMBASE (1980 to 3 December 2013 (Week 48)) and the metaRegister of Controlled Trials. Additionally, we searched ongoing trials through the National Research Register, the ClinicalTrials.gov registry and grey literature. We screened online conference indices from relevant scientific meetings (2006 to 2014) to look for eligible trials. We applied no language restrictions.

SELECTION CRITERIA

All randomised controlled trials comparing any statin treatment before cardiac surgery, for any given duration and dose, versus no preoperative statin therapy (standard of care) or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors evaluated trial quality and extracted data from titles and abstracts identified by electronic database searches according to predefined criteria. Accordingly, we retrieved full-text articles of potentially relevant studies that met the inclusion criteria to assess definitive eligibility for inclusion. We reported effect measures as odds ratios (ORs) or weighted mean differences (WMDs) with 95% confidence intervals (95% CIs).

MAIN RESULTS

We identified 17 randomised controlled studies including a total of 2138 participants undergoing on-pump or off-pump cardiac surgical procedures, and added to this review six studies with 1154 additional participants. Pooled analysis showed that statin treatment before surgery reduced the incidence of postoperative atrial fibrillation (AF) (OR 0.54, 95% CI 0.43 to 0.67; P value < 0.01; 12 studies, 1765 participants) but failed to influence short-term mortality (OR 1.80, 95% CI 0.38 to 8.54; P value = 0.46; two studies, 300 participants) or postoperative stroke (OR 0.70, 95% CI 0.14 to 3.63; P value = 0.67; two studies, 264 participants). In addition, statin therapy was associated with a shorter stay for patients on the intensive care unit (ICU) (WMD -3.19 hours, 95% CI -5.41 to -0.98; nine studies, 721 participants) and in the hospital (WMD -0.48 days, 95% CI -0.78 to -0.19; 11 studies, 1137 participants) when significant heterogeneity was observed. Results showed no reduction in myocardial infarction (OR 0.48, 95% CI 0.21 to 1.13; seven studies, 901 participants) or renal failure (OR 0.57, 95% CI 0.30 to 1.10; five studies, 467 participants) and were not affected by subgroup analysis. Trials investigating this safety endpoint reported no major or minor perioperative side effects of statins.

AUTHORS' CONCLUSIONS

Preoperative statin therapy reduces the odds of postoperative atrial fibrillation (AF) and shortens the patient's stay on the ICU and in the hospital. Statin pretreatment had no influence on perioperative mortality, stroke, myocardial infarction or renal failure, but only two of all included studies assessed mortality. As analysed studies included mainly individuals undergoing myocardial revascularisation, results cannot be extrapolated to patients undergoing other cardiac procedures such as heart valve or aortic surgery.

Meta-analysis of 12 trials evaluating the effects of statins on decreasing atrial fibrillation after coronary artery bypass grafting

Atrial fibrillation (AF) is a common arrhythmia encountered after coronary artery bypass graft surgery (CABG) and is associated with poor outcomes. The purpose of this study was to examine whether initiation of statins before CABG reduces the risk of postoperative AF. We searched for clinical trials that randomized patients who underwent CABG to preoperative statin therapy versus placebo. We required that the trial reported the incidence of postoperative AF. Random-effects summary odds ratio (OR) were constructed. Sensitivity analysis for the trials that reported AF as a primary outcome along with subgroup analyses according to the different statins used was also conducted. Twelve trials with 2,980 patients met our inclusion criteria. Atorvastatin was tested in 8 trials, whereas rosuvastatin was studied in 2 studies. Statins were associated with a lower risk of postoperative AF (OR 0.42, 95% confidence interval [CI] 0.27 to 0.66, p <0.0001). There was benefit with atorvastatin (OR 0.35, 95% CI 0.25 to 0.50, p <0.0001) but not rosuvastatin (OR 0.69, 95% CI 0.28 to 1.71, p = 0.42). On sensitivity analysis limited to trials that reported AF as a primary outcome, the risk of postoperative AF was still reduced with statins (OR 0.40, 95% CI 0.25 to 0.90, p = 0.02). The mean duration of the hospital stay was significantly lower in the statin group: 8.5 ± 1.8 days versus 9.1 ± 2.2 days (p <0.0001). Statin therapy, particularly atorvastatin, before CABG was associated with a reduction in the risk of postoperative AF.

Does preoperative statin therapy prevent postoperative atrial fibrillation in patients undergoing cardiac surgery?

A best evidence topic was written according to a structured protocol. The question addressed was: does preoperative statin therapy prevent postoperative atrial fibrillation (AF) in patients undergoing cardiac surgery? There were 445 papers found using the reported search. From these, 12 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. This paper includes three systematic reviews with meta-analysis, five randomized controlled trials and four retrospective studies. All the papers compared either all or some of the following postoperative complications: mortality, morbidity, AF, length of hospital stay (intensive care unit and hospital) and inflammatory markers. The largest study in this paper includes a systematic review of 91 491 patients that showed a reduction in postoperative AF with preoperative statin therapy (OR = 0.71, 95% CI 0.61-0.82, P <0.0001). However, the durations (3 days to 2 months preoperatively), doses and types of preoperative statin differed between these papers. Although the majority of studies (10 of 12) support the use of statins preoperatively, 2 studies found no association between preoperative statin therapy and the reduction of postoperative AF. In conclusion, the available evidence suggests that preoperative statin therapy in patients undergoing elective cardiac surgery is associated with the following: (1) a lower incidence and risk of developing postoperative AF, (2) reduced stroke, (3) a shorter hospital stay and (4) reduced levels of inflammatory markers postoperatively. However, while the evidence supports the use of statins preoperatively, the optimal duration, dose and type of statin cannot be concluded from this review.

Anticoagulation strategies for the management of postoperative atrial fibrillation

Patients undergoing thoracic and cardiac procedures are at the highest risk for postoperative atrial fibrillation (POAF). POAF is associated with poor short-term and long-term outcomes, including high rates of early and late stroke, and late mortality. Patients with POAF that persists for longer than 48 hours should be anticoagulated on warfarin. Three new oral anticoagulants are available for the treatment of nonvalvular atrial fibrillation and have been found to be as efficacious or superior to warfarin in the prevention of stroke in high-risk patients, with similar to lower rates of major bleeding, and lower rates of intracranial hemorrhage.

Clinical update on the management of atrial fibrillation

Atrial fibrillation (AF) is a cardiac arrhythmia associated with significant morbidity and mortality, affecting more than 3 million people in the United States and 1-2% of the population worldwide. Its estimated prevalence is expected to double within the next 50 years. During the past decade, there have been significant advances in the treatment of AF. Studies have demonstrated that a rate control strategy, with a target resting heart rate between 80 and 100 beats/minute, is recommended over rhythm control in the vast majority of patients. The CHA2 DS2 ≥ (congestive heart failure, hypertension, age ≥ 65 yrs, diabetes mellitus, stroke or transient ischemic attack, vascular disease, female gender) scoring system is a potentially useful stroke risk stratification tool that incorporates additional risk factors to the commonly used CHADS2 (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke transient ischemic attack) scoring tool. Similarly, a convenient scheme, termed HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly), to assess bleeding risk has emerged that may be useful in select patients. Furthermore, new antithrombotic strategies have been developed as potential alternatives to warfarin, including dual-antiplatelet therapy with clopidogrel plus aspirin and the development of new oral anticoagulants such as dabigatran, rivaroxaban, and apixaban. Vernakalant has emerged as another potential option for pharmacologic conversion of AF, whereas recent trials have better defined the role of dronedarone in the maintenance of sinus rhythm. Finally, catheter ablation represents another alternative to manage AF, whereas upstream therapy with inhibitors of the renin-angiotensin-aldosterone system, statins, and polyunsaturated fatty acids could potentially prevent the occurrence of AF. Despite substantial progress in the management of AF, significant uncertainty surrounds the optimal treatment of this condition.

Continuative statin therapy after percutaneous coronary intervention improves outcome in coronary bypass surgery: a propensity score analysis of 2501 patients

OBJECTIVES

A history of percutaneous coronary intervention increases the risk of death and complications of coronary artery bypass grafting. This retrospective multicenter study evaluated the impact of continuative use of statin on postoperative outcomes when subsequent elective coronary artery bypass grafting is required after percutaneous coronary intervention.

METHODS

Among 14,575 patients who underwent isolated first-time coronary artery bypass grafting between January 2000 and December 2010, 2501 who had previous percutaneous coronary intervention with stenting and fulfilled inclusion criteria were enrolled. Continuative statin therapy was used in 1528 patients and not used in 973 patients. Logistic multiple regression and propensity score analyses were used to assess the risk-adjusted impact of statin therapy on in-hospital mortality and major adverse cardiac events. The Cox proportional hazards model was constructed to assess the effect of continuative statin therapy on 24-month outcome.

RESULTS

At multivariate analysis, age more than 70 years, 3-vessel or 2-vessel plus left main coronary disease, multivessel percutaneous coronary intervention, ejection fraction 0.40 or less, diabetes mellitus, and logistic European System for Cardiac Operative Risk Evaluation 5 or greater were independent predictors of hospital mortality and major adverse cardiac events. After propensity score matching, conditional logistic regression analysis demonstrated that continuative statin therapy before coronary artery bypass grafting reduced the risk for hospital and 2-year mortality (odds ratio [OR], 0.27; 95% confidence interval [CI], 0.12-0. 57; P=.004 and OR, 0.6; 95% CI, 0.36-0.96; P=.04, respectively) and major adverse cardiac events (OR, 0.31; 95% CI, 0.18-0.78; P=.003 and OR, 0.5; 95% CI, 0.34-0.76; P=.006, respectively).

CONCLUSIONS

Long-term statin treatment after percutaneous coronary intervention improves early and midterm outcome when surgical revascularization will be required.

Management strategies in cardiac surgery for postoperative atrial fibrillation: contemporary prophylaxis and futuristic anticoagulant possibilities

With more than a third of patients expected to endure the arrhythmia at any given time point, atrial fibrillation after cardiac surgery becomes a vexing problem in the postoperative care of cardiac surgery patients. The impact on patient care covers a spectrum from the more common clinically insignificant sequelae to debilitating embolic events. Despite this, postoperative atrial fibrillation generally masquerades as being insignificant, or at most as an anticipated inherent risk, merely extending one's hospital stay by a few days. As an independent risk factor for stroke, early and late mortality, and being a multibillion dollar strain on the healthcare system annually, postoperative atrial fibrillation is far more flagrant than a mere inherent risk. It is a serious medical quandary, which is not recognized as such. Though complete prevention is unrealistic, a step-wise treatment strategy that incorporates multiple preventative modalities can significantly reduce the impact of postoperative atrial fibrillation on patient care. The aims of this review are to present a brief overview of the arrhythmia's etiology, risk factors, and preventative strategies to reduce associated morbidities. Newer anticoagulants and the potential role of these drugs on future treatment paradigms are also discussed.

Perioperative statin therapy for improving outcomes during and after noncardiac vascular surgery

BACKGROUND

Patients undergoing vascular surgery are a high-risk population with widespread atherosclerosis, an adverse cardiovascular risk profile and often multiple co-morbidities. Postoperative cardiovascular complications, including myocardial infarct (MI), are common. Statins are the medical treatment of choice to reduce high cholesterol levels. Evidence is accumulating that patients taking statins at the time of surgery are protected against a range of perioperative complications, but the specific benefits for patients undergoing noncardiac vascular surgery are not clear.

OBJECTIVES

We examined whether short-term statin therapy, commenced before or on the day of noncardiac vascular surgery and continuing for at least 48 hours afterwards, improves patient outcomes including the risk of complications, pain, quality of life and length of hospital stay. We also examined whether the effect of statin therapy on these outcomes changes depending on the dose of statin received.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 7), MEDLINE via Ovid SP (1966 to August 2012), EMBASE via Ovid SP (1966 to August 2012), CINAHL via EBSCO host (1966 to August 2012) and ISI Web of Science (1946 to July 2012) without any language restriction. We used a combination of free text search and controlled vocabulary search. The results were limited to randomized controlled clinical trials (RCTs). We conducted forwards and backwards citation of key articles and searched two clinical trial Websites for ongoing trials (www.clinicaltrials.gov and http://www.controlled-trials.com).

SELECTION CRITERIA

We included RCTs that had compared short-term statin therapy, either commenced de novo or with existing users randomly assigned to different dosages, in adult participants undergoing elective and emergency noncardiac arterial surgery, including both open and endovascular procedures. We defined short-term as commencing before or on the day of surgery and continuing for at least 48 hours afterwards.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data, including information on adverse events. We contacted study authors for additional information. We performed separate analyses for the comparisons of statin with placebo/no treatment and between different doses of statin. We presented results as pooled risk ratios (RRs) with 95% confidence intervals (CIs) based on random-effects models (inverse variance method). We employed the Chi(2) test and calculated the I(2) statistic to investigate study heterogeneity.

MAIN RESULTS

We identified six eligible studies in total. The six Included studies were generally of high quality, but the largest eligible study was excluded because of concerns about its validity. Study populations were statin naive, which led to a considerable loss of eligible participants.Five RCTs compared statin use with placebo or standard care. We pooled results from three studies, with a total of 178 participants, for mortality and non-fatal event outcomes. In the statin group, 7/105 (6.7%) participants died within 30 days of surgery, as did 10/73 (13.7%) participants in the control group. Only one death in each group was from cardiovascular causes, with an incidence of 0.95% in statin participants and 1.4% in control participants, respectively. All deaths occurred in a single study population, and so effect estimates were derived from one study only. The risk ratio (RR) of all-cause mortality in statin users showed a non-significant decrease in risk (RR 0.73, 95% CI 0.31 to 1.75). For cardiovascular death, the risk ratio was 1.05 (95% CI 0.07 to 16.20). Non-fatal MI within 30 days of surgery was reported in three studies and occurred in 4/105 (3.8%) participants in the statin group and 8/73 (11.0%) participants receiving placebo, for a non-significant decrease in risk (RR 0.47, 95% CI 0.15 to 1.52). Several studies reported muscle enzyme levels as safety measures, but only three (with a total of 188 participants) reported explicitly on clinical muscle syndromes, with seven events reported and no significant difference found between statin users and controls (RR 0.94, 95% CI 0.24 to 3.63). The only participant-reported outcome was nausea in one small study,with no significant difference in risk between groups.Two studies compared different doses of atorvastatin, with a total of 145 participants, but reported data were not sufficient to allow us to determine the effect of higher doses on any outcome.

AUTHORS' CONCLUSIONS

Evidence was insufficient to allow review authors to conclude that statin use resulted in either a reduction or an increase in any of the outcomes examined. The existing body of evidence leaves questions about the benefits of perioperative use of statins for vascular surgery unanswered. Widespread use of statins in the target population means that it may now be difficult for researchers to undertake the large RCTs needed to demonstrate any effect on the incidence of postoperative cardiovascular events. However, participant-reported outcomes have been neglected and warrant further study.

The preventive effect of statin therapy on new-onset and recurrent atrial fibrillation in patients not undergoing invasive cardiac interventions: a systematic review and meta-analysis

BACKGROUND

Previous meta-analyses suggest that pre-procedural use of statin therapy may reduce atrial fibrillation (AF) following invasive cardiac interventions (coronary artery by-pass grafting and percutaneous coronary intervention). However, the current evidence on the benefit of statins unrelated to invasive cardiac interventions has not been clarified systematically.

METHODS

Through a systematic literature search, trials examining the effect of statin therapy on AF were selected. Trials using statins before any percutaneous or surgical cardiac interventions were excluded.

RESULTS

The search identified 11 randomized and 16 observational eligible studies, totaling 106,640 patients receiving statin therapy and 129,305 serving as controls. Fourteen studies investigated the effect of statins on new-onset AF, 13 studies investigated the effect of statins on recurrent AF and one in both new-onset and recurrent AF. In the statin versus control group the mean age was 60.7 ± 8.3 versus 68.6 ± 6.2 years and females comprised 8.4% versus 10.3%. Statin therapy was associated with significant reduction of AF (Risk ratio (RR): 0.81 [95% confidence interval (CI): 0.80-0.83], p<0.001) combining all studies. Assessing exclusively randomized trials, statin therapy showed no significant risk reduction (RR: 0.97 [95%CI: 0.90-1.05], p=0.509), heterogeneity p>0.05. Assessing exclusively observational studies the risk reduction of new-onset AF was 12% (RR: 0.88 [95%CI: 0.85-0.91], p<0.001) and recurrent AF 15% (RR: 0.85 [95%CI: 0.80-0.90], p<0.001), heterogeneity p<0.001.

CONCLUSION

The hitherto published randomized clinical trials do not support a beneficial effect of statins on AF in patients not undergoing invasive cardiac interventions. This is in contrast to the results of observational and interventional studies.

Primary Prevention of Atrial Fibrillation where are we in 2012?

Drugs to alter or delay myocardial remodelling associated with heart failure, hypertension, or inflammation in the post-operative setting, may prevent the development of atrial fibrillation. Current experimental and clinical evidences support specific treatments for defined patient population (i.e. ACE-inhibitors and ARB for chronic heart failure and hypertension expecially with LV hypertrophy; statins, corticosteroids and possibly colchicine after cardiac surgery).

Feasibility of landiolol and bisoprolol for prevention of atrial fibrillation after coronary artery bypass grafting: a pilot study

BACKGROUND

We previously performed a trial of intravenous landiolol hydrochloride during and after cardiac surgery (the PASCAL trial) and demonstrated a preventive effect on postoperative atrial fibrillation (AF). In the present study, we investigated the efficacy of increasing the dose and administration period of landiolol for prevention of postoperative AF, as well as the effect of oral bisoprolol in the early postoperative period.

PATIENTS AND METHODS

A total of 105 patients who underwent coronary artery bypass grafting were randomized to 3 groups: a group receiving intravenous landiolol perioperatively at 5 μg/kg/min for 3 days (group L), a group receiving oral bisoprolol postoperatively together with landiolol (group LB), and a control group without beta-blocker therapy (group C). The primary end point was the presence/absence of postoperative AF. Secondary end points were (1) the early clinical outcome, (2) hemodynamics, (3) cardiac enzymes (creatine kinase isoenzyme MB, troponin-I, and human heart fatty acid-binding protein), (4) high-sensitivity C-reactive protein (hs-CRP) and pentraxin-3, (5) asymmetric dimethylarginine (ADMA), and (6) brain natriuretic peptide.

RESULTS

Postoperative AF occurred in 14.5% of group L, 9.1% of group LB, and 35.3% of group C. A significant difference was observed between groups LB and C. Significantly higher levels of troponin-I, human heart fatty acid-binding protein, hs-CRP, pentraxin-3, and ADMA were noted in group C than in groups L and LB.

CONCLUSIONS

Landiolol and bisoprolol prevented postoperative AF. The anti-ischemic, anti-inflammatory, and anti-oxidant effects of these beta-blockers presumably inhibited the onset of AF.

Statin treatment increases lifespan and improves cardiac health in Drosophila by decreasing specific protein prenylation

Statins such as simvastatin are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and standard therapy for the prevention and treatment of cardiovascular diseases in mammals. Here we show that simvastatin significantly increased the mean and maximum lifespan of Drosophila melanogaster (Drosophila) and enhanced cardiac function in aging flies by significantly reducing heart arrhythmias and increasing the contraction proportion of the contraction/relaxation cycle. These results appeared independent of internal changes in ubiquinone or juvenile hormone levels. Rather, they appeared to involve decreased protein prenylation. Simvastatin decreased the membrane association (prenylation) of specific small Ras GTPases in mice. Both farnesyl (L744832) and type 1 geranylgeranyl transferase (GGTI-298) inhibitors increased Drosophila lifespan. These data are the most direct evidence to date that decreased protein prenylation can increase cardiac health and lifespan in any metazoan species, and may explain the pleiotropic (non-cholesterol related) health effects of statins.