Fluvastatin and perioperative events in patients undergoing vascular surgery

Cardiopulmonary exercise testing prior to radical cystectomy: a systematic review and meta-analysis

OBJECTIVE

To identify the association between cardiopulmonary exercise testing (CPET) and outcomes of radical cystectomy (RC), as RC is historically associated with high rates of short- and long-term morbidity and mortality.

METHODS

This quantitative systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. An electronic literature search was conducted to identify all relevant studies evaluating the relationship between CPET parameters and RC outcomes. The primary outcome was short-term mortality. Secondary outcomes included hospital length of stay (LOS) and rate of serious adverse events as defined by the Clavien-Dindo classification.

RESULTS

The search identified six studies for inclusion. A total of 546 patients underwent CPET prior to RC. There were significantly more deaths following RC observed in patients with poorer cardiopulmonary function (risk ratio RR 5.80, 95% confidence interval 4.96-6.78). There was no significant association between CPET parameters and adverse events or hospital LOS.

CONCLUSIONS

The present systematic review and meta-analysis identified a greater risk of 90-day mortality in patients with poorer cardiorespiratory function, as measured by CPET. However, there remains a paucity of robust clinical data and further high-quality studies are required to verify these results.

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.

[Preoperative evaluation of adult patients before elective, non-cardiothoracic surgery : A joint recommendation of the German Society for Anesthesiology and Intensive Care Medicine, the German Society for Surgery and the German Society for Internal Medicine]

The 70 recommendations summarize the current status of preoperative risk evaluation of adult patients prior to elective non-cardiothoracic surgery. Based on the joint publications of the German scientific societies for anesthesiology and intensive care medicine (DGAI), surgery (DGCH), and internal medicine (DGIM), which were first published in 2010 and updated in 2017, as well as the European guideline on preoperative cardiac risk evaluation published in 2022, a comprehensive re-evaluation of the recommendation takes place, taking into account new findings, the current literature, and current guidelines of international professional societies. The revised multidisciplinary recommendation is intended to facilitate a structured and common approach to the preoperative evaluation of patients. The aim is to ensure individualized preparation for the patient prior to surgery and thus to increase patient safety. Taking into account intervention- and patient-specific factors, which are indispensable in the preoperative risk evaluation, the perioperative risk for the patient should be minimized and safety increased. The recommendations for action are summarized under "General Principles (A)," "Advanced Diagnostics (B)," and the "Preoperative Management of Continuous Medication (C)." For the first time, a rating of the individual measures with regard to their clinical relevance has been given in the present recommendation. A joint and transparent agreement is intended to ensure a high level of patient orientation while avoiding unnecessary preliminary examinations, to shorten preoperative examination procedures, and ultimately to save costs. The joint recommendation of DGAI, DGCH and DGIM reflects the current state of knowledge as well as the opinion of experts. The recommendation does not replace the individualized decision between patient and physician about the best preoperative strategy and treatment.

Dyslipidemia and peripheral arterial disease

Peripheral arterial disease (PAD) affects 12 % of adult population and is increasing globally and in India. Peripheral arterial disease when associated with atherosclerosis in two or more other arterial beds such as coronary artery disease (CAD), mesenteric/renal artery and cerebrovascular disease (CVD), is known as polyvascular disease. The Reduction of Atherothrombosis for Continued Health (REACH) registry reported that 1 out of 6 patients had multi-vascular bed involvement. Progression of PAD to critical limb ischaemia (CLI) is seen in 1 % of affected patients per year, but patients who progress to CLI may have a 10- to 15-fold increased risk of cardiovascular death. The 2019 ECS/EAS guidelines for the management of dyslipidaemias have suggested that for primary or secondary prevention in very high risk, patients should follow a therapeutic regimen that achieves >50 % LDL-C reduction from baseline and an LDL-C goal of <55 mg/dl. High Intensity Statin is mainstay of treatment but optimal management is inadequate. Statin treatment reduces all-cause mortality by 39 %, CV death by 41 %, CV outcomes by 34 %, ischaemic stroke by 28 %, acute limb ischaemia by 30 % and amputations by 35 %. Ezetimibe when added to statins in IMPROVE-IT trial, showed significant reduction of MACE. PCSK9 inhibitor (FOURIER TRIAL) showed reduction in primary end point in PAD vs Non PAD patients (3.5 % vs 1.6 %). There is a critical need for an Indian multi-disciplinary task force for research on the direct impact of lipid-lowering agents on limb salvage rates and major limb-related events in PAD patients.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Statin therapy after elective abdominal aortic aneurysm repair improves long-term survival

BACKGROUND

Patients with abdominal aortic aneurysms are at high risk of cardiovascular events. Although statin therapy is indicated for most of these patients, no specific recommendation regarding the intensity of therapy exists. The aim of this study was to assess the possible effect of statin therapy on survival of patients undergoing abdominal aortic aneurysm repair and to investigate if high-intensity statin therapy was superior to low-moderate-intensity therapy.

METHODS

Data from nationwide Swedish registers on hospital admissions, operations, and medications for patients undergoing elective abdominal aortic aneurysm repair from 2006 to 2018 were collected. The effect of statin use was evaluated in three separate propensity score matched cohorts: perioperative mortality was analysed according to whether patients were on statins before abdominal aortic aneurysm repair or not; long-term survival was assessed according to whether patients were on statins during follow-up or not; and, for those on statins after surgery, long-term survival was analysed according to whether patients were on high-intensity or low-moderate-intensity statin therapy.

RESULTS

Preoperative statin use did not reduce 90-day perioperative mortality (OR 0.99, 95% c.i. 0.77 to 1.28), whilst there was a marked benefit regarding long-term survival for postoperative statin users (HR 1.43, 95% c.i. 1.34 to 1.54). High-intensity statin therapy had no advantage over low-medium-intensity statin therapy with regards to long-term survival (HR 1.00, 95% c.i. 0.80 to 1.25).

CONCLUSION

In this nationwide propensity score matched cohort study, preoperative statin treatment had no benefit regarding 90-day perioperative survival, but postoperative statin treatment markedly improved long-term survival. No additional benefit regarding high-dose statin treatment could be confirmed in this analysis.

Enhanced recovery after surgery (ERAS) for vascular surgery: an evidence map and scoping review

BACKGROUND

Enhanced recovery after surgery (ERAS) interventions aim to improve patient outcomes. Vascular surgery patients have unique requirements and it is unclear which ERAS interventions are supported by an evidence base.

METHODS

We conducted a scoping review to identify ERAS randomized controlled trials (RCTs) published in the biomedical or nursing literature. We assessed interventions for applicability to vascular surgery and differentiated interventions given at preadmission, preoperative, intraoperative, and postoperative surgery stages. We documented the research in an evidence map.

RESULTS

We identified 76 relevant RCTs. Interventions were mostly administered in preoperative (23 RCTs; 30%) or intraoperative surgery stages (35 RCTs; 46%). The majority of studies reported mortality outcomes (44 RCTs; 58%), but hospital (27 RCTs; 35%) and intensive care unit (9 RCTs; 12%) length of stay outcomes were less consistently described.

CONCLUSION

The ERAS evidence base is growing but contains gaps. Research on preadmission interventions and more consistent reporting of key outcomes is needed.

Induction of JAK2/STAT3 pathway contributes to protective effects of different therapeutics against myocardial ischemia/reperfusion

Insufficiency in coronary blood supply results in myocardial ischemia and consequently, various clinical syndromes and irreversible injuries. Myocardial damage occurs as a result of two processes during acute myocardial infarction (MI): ischemia and subsequent reperfusion. According to the available evidence, oxidative stress, excessive inflammation reaction, reactive oxygen species (ROS) generation, and apoptosis are crucial players in the pathogenesis of myocardial ischemia/reperfusion (IR) injury. There is emerging evidence that Janus tyrosine kinase 2 (JAK2) signal transducer and activator of the transcription 3 (STAT3) pathway offers cardioprotection against myocardial IR injury. This article reviews therapeutics that exert cardioprotective effects against myocardial IR injury through induction of JAK2/STAT3 pathway.

Statins in High Cardiovascular Risk Patients: Do Comorbidities and Characteristics Matter?

Atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality are decreasing in high-income countries, but ASCVD remains the leading cause of morbidity and mortality in high-income countries. Over the past few decades, major risk factors for ASCVD, including LDL cholesterol (LDL-C), have been identified. Statins are the drug of choice for patients at increased risk of ASCVD and remain one of the most commonly used and effective drugs for reducing LDL cholesterol and the risk of mortality and coronary artery disease in high-risk groups. Unfortunately, doctors tend to under-prescribe or under-dose these drugs, mostly out of fear of side effects. The latest guidelines emphasize that treatment intensity should increase with increasing cardiovascular risk and that the decision to initiate intervention remains a matter of individual consideration and shared decision-making. The purpose of this review was to analyze the indications for initiation or continuation of statin therapy in different categories of patient with high cardiovascular risk, considering their complexity and comorbidities in order to personalize treatment.

Effect of Perioperative Lipid Status on Clinical Outcomes after Cardiac Surgery

Patients undergoing cardiac surgery are at increased cardiovascular risk, which includes altered lipid status. However, data on the effect of cardiac surgery and cardiopulmonary bypass (CPB) on plasma levels of key lipids are scarce. We investigated potential effects of CPB on plasma lipid levels and associations with early postoperative clinical outcomes. This is a prospective bio-bank study of patients undergoing elective cardiac surgery at our center January to December 2019. The follow-up period was 1 year after surgery. Blood sampling was performed before induction of general anesthesia, upon weaning from cardiopulmonary bypass (CPB), and on the first day after surgery. Clinical end points included the incidence of postoperative stroke, myocardial infarction, and death of any cause at 30 days after surgery as well as 1-year all-cause mortality. A total of 192 cardiac surgery patients (75% male, median age 67.0 years (interquartile range 60.0-73.0), median BMI 26.1 kg/m² (23.7-30.4)) were included. A significant intraoperative decrease in plasma levels compared with preoperative levels (all p < 0.0001) was observed for total cholesterol (TC) (Cliff's delta d: 0.75 (0.68-0.82; 95% CI)), LDL-Cholesterol (LDL-C) (d: 0.66 (0.57-0.73)) and HDL-Cholesterol (HDL-C) (d: 0.72 (0.64-0.79)). At 24h after surgery, the plasma levels of LDL-C (d: 0.73 (0.650.79)) and TC (d: 0.77 (0.69-0.82)) continued to decrease compared to preoperative levels, while the plasma levels of HDL-C (d: 0.46 (0.36-0.55)) and TG (d: 0.40 (0.29-0.50)) rebounded, but all remained below the preoperative levels (p < 0.001). Mortality at 30 days was 1.0% (N = 2/192), and 1-year mortality was 3.8% (N = 7/186). Postoperative myocardial infarction occurred in 3.1% of patients (N = 6/192) and postoperative stroke in 5.8% (N = 11/190). Adjusting for age, sex, BMI, and statin therapy, we noted a protective effect of postoperative occurrence of stroke for pre-to-post-operative changes in TC (adjusted odds ratio (OR) 0.29 (0.07-0.90), p = 0.047), in LDL-C (aOR 0.19 (0.03-0.88), p = 0.045), and in HDL-C (aOR 0.01 (0.00-0.78), p = 0.039). No associations were observed between lipid levels and 1-year mortality. In conclusion, cardiac surgery induces a significant sudden drop in levels of key plasma lipids. This effect was pronounced during the operation, and levels remained significantly lowered at 24 h after surgery. The intraoperative drops in LDL-C, TC, and HDL-C were associated with a protective effect against occurrence of postoperative stroke in adjusted models. We demonstrate that the changes in key plasma lipid levels during surgery are strongly correlated, which makes attributing the impact of each lipid to the clinical end points, such as postoperative stroke, a challenging task. Large-scale analyses should investigate additional clinical outcome measures.

Perioperative Statin Use May Reduce Postoperative Arrhythmia Rates After Total Joint Arthroplasty

BACKGROUND

Postoperative arrhythmias are associated with increased morbidity and mortality in total joint arthroplasty (TJA) patients. HMG-CoA (3-hydroxy-3-methyl-glutaryl-CoA) reductase inhibitors (statins) decrease atrial fibrillation rates after cardiac surgery, but it is unknown if this cardioprotective effect is maintained after joint reconstruction surgery. We aim to determine if perioperative statin use decreases the incidence of 90-day postoperative arrhythmias in patients undergoing primary TJA.

METHODS

We performed a single-center retrospective cohort study in which 231 primary TJA patients (109 hips, 122 knees) received simvastatin 80 mg daily during their hospitalization as part of a single surgeon's standard postoperative protocol. This cohort was matched to 966 primary TJA patients (387 hips and 579 knees) that did not receive simvastatin. New-onset arrhythmias (bradycardia, atrial fibrillation/tachycardia/flutter, paroxysmal supraventricular tachycardia, and ventricular tachycardia) and complications (readmissions, thromboembolism, infection, and dislocation) within 90 days of the procedure were documented. Categorical variables were analyzed using Fisher's exact tests. Our study was powered to detect a 3% difference in arrhythmia rates.

RESULTS

Within 90 days postoperatively, arrhythmias occurred in 1 patient (0.4%) who received a perioperative statin, 39 patients (4.0%) who did not receive statins (P = .003), and 24 patients (4.2%) who were on outpatient statins (P = .005). This is 10-fold reduction in the relative risk of developing a postoperative arrhythmia within 90 days of arthroplasty and an absolute risk reduction of 3.6%.

CONCLUSION

Treating as few as 28 patients with perioperative simvastatin prevents one new cardiac arrhythmia within 90 days in statin-naïve patients undergoing TJA.

Statin use, development of sarcopenia, and long-term survival after endovascular aortic repair

OBJECTIVE

Statin therapy, associated with improved short-term survival after treatment of abdominal aortic aneurysms, may also predispose to muscle side effects. Evidence on statin-related sarcopenia is limited mainly to muscle function, and it is subject to several sources of bias. In the long term, postoperative development of sarcopenia is linked to mortality after endovascular repair (EVAR). We investigated statin use and long-term postoperative mortality after EVAR in relation to objective measurable markers of sarcopenia (psoas muscle surface area and density).

METHODS

Altogether 216 abdominal aortic aneurysm patients treated with EVAR between 2006 and 2014 at Tampere University Hospital (Finland) were retrospectively studied. Psoas muscle parameters at the L3 level were evaluated from baseline and mainly 1- to 3-year follow-up computed tomography studies. Cox regression was used to study the association between statin medication, psoas muscle changes, and all-cause mortality.

RESULTS

The majority of patients were male (87%), and the mean age was 77.7 years (standard deviation, 7.4). The median duration of follow-up was 6.3 years (interquartile range, 3.5) with a total mortality of 54.2% (n = 117). Regardless of a higher burden of comorbidities, statin users (n = 119) had lower mortality when compared with nonusers (multivariable hazard ratio [HR]: 0.69, 95% confidence interval: 0.48-0.99, P = .048). Furthermore, statin use was not associated with inferior muscle parameter values, and the relative change in psoas muscle area was actually lower in statin users compared with nonusers (-15.7% and -21.1%, P < .046).

CONCLUSIONS

Statin use is associated with lower long-term mortality among patients undergoing EVAR without predisposing to increased sarcopenia.

Impact of statin pretreatment on the complications of carotid stenting in asymptomatic patients: observational study

Background

Carotid stenosis is a known risk factor for ischemic stroke, and carotid artery stenting is an effective preventive procedure. However, the stroke risk reduction for asymptomatic patients is small. Therefore, it is important to reduce the risk of complications, particularly in asymptomatic carotid stenosis. Statins are known to reduce the overall risk of periprocedural complications, although there is a lack of data focusing on asymptomatic patients. We aimed to investigate whether different doses of statin pretreatment can reduce periprocedural complications of carotid artery stenting (CAS) in patients with asymptomatic carotid artery stenosis.

Methods

Between July 2003 and June 2013, 276 consecutive patients received CAS for asymptomatic carotid stenosis. Periprocedural complications included the outcome of stroke, myocardial infarction, or death within 30 days of CAS. Statin pretreatment was categorized as no-statin (n = 87, 31.5%), standard-dose (< 40 mg, n = 139, 50.4%), and high-dose statin (≥40 mg, n = 50, 18.1%) according to the atorvastatin equivalent dose. The Cochran-Armitage (CA) trend test was performed to investigate the association of periprocedural complications with statin dose.

Results

The overall periprocedural complication rate was 3.3%. There was no significant difference in the risk of periprocedural complications between the three groups (no statin: n = 3 [3.4%]; standard-dose: n = 4 [2.9%]; high-dose n = 2 [4.0%] p = 0.923). The CA trend test did not demonstrate a trend in the proportion of periprocedural complications across increasing statin equivalent doses (p = 0.919).

Conclusions

Statin pretreatment before CAS showed neither absolute nor dose-dependent effects against periprocedural complications in asymptomatic patients undergoing CAS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02104-z.

Usefulness of preoperative coronary computed tomography angiography in high risk non-cardiovascular surgery old patients with unknown or suspected coronary artery disease

BACKGROUND

Cumulative evidence has shown that the non-invasive modality of coronary computed tomography angiography (CCTA) has evolved as an alternative to invasive coronary angiography, which can be used to quantify plaque burden and stenosis and identify vulnerable plaque, assisting in diagnosis, prognosis and treatment. With the increasing elderly population, many patients scheduled for non-cardiovascular surgery may have concomitant coronary artery disease (CAD). The aim of this study was to investigate the usefulness of preoperative CCTA to rule out or detect significant CAD in this cohort of patients and the impact of CCTA results to clinical decision-making.

METHODS

841 older patients (age 69.5 ± 5.8 years, 74.6% males) with high risk non-cardiovascular surgery including 771 patients with unknown CAD and 70 patients with suspected CAD who underwent preoperative CCTA were retrospectively enrolled. Multivariate logistic regression analysis was performed to determine predictors of significant CAD and the event of cancelling scheduled surgery in patients with significant CAD.

RESULTS

677 (80.5%) patients had non-significant CAD and 164 (19.5%) patients had significant CAD. Single-, 2-, and 3- vessel disease was found in 103 (12.2%), 45 (5.4%) and 16 (1.9%) patients, respectively. Multivariate analysis demonstrated that positive ECG analysis and Agatston score were independently associated with significant CAD, and the optimal cutoff of Agatston score was 195.9. The event of cancelling scheduled surgery was increased consistently according to the severity of stenosis and number of obstructive major coronary artery. Multivariate analysis showed that the degree of stenosis was the only independent predictor for cancelling scheduled surgery. In addition, medication using at perioperative period increased consistently according to the severity of stenosis.

CONCLUSIONS

In older patients referred for high risk non-cardiovascular surgery, preoperative CCTA was useful to rule out or detect significant CAD and subsequently influence patient disposal. However, it might be unnecessary for patients with negative ECG and low Agatston score. Trial registration Retrospectively registered.

Tranexamic acid and rosuvastatin in patients at risk of cardiovascular events after noncardiac surgery: a pilot of the POISE-3 randomized controlled trial

Background

Surgical bleeding is associated with postoperative cardiovascular complications. The efficacy and safety of tranexamic acid (TXA) in noncardiac surgery are still uncertain. Statins may prevent perioperative cardiovascular complications. We conducted a pilot to assess the feasibility of a perioperative trial of TXA and rosuvastatin.

Methods

Using a factorial design, we randomized patients at cardiovascular risk undergoing noncardiac surgery to intravenous TXA (1 g at the start and end of surgery) or placebo, and oral rosuvastatin (40 mg before and 20 mg daily for 30 days after surgery) or placebo. Feasibility outcomes included recruitment rates, follow-up, and compliance to interventions. Clinical outcomes were secondarily explored.

Results

After 3 months, we changed the design to a partial factorial due to the difficult recruitment of statin-naive patients. Over 6 months, 100 patients were randomized in the TXA trial (49 TXA, 51 placebo), 34 in the rosuvastatin trial (18 rosuvastatin, 16 placebo). Ninety-two percent (95% CI 80–98) of TXA and 86% (95% CI 74–94) of TXA-placebo patients received the 2 study doses. Thirty-three percent (95% CI 13–59) of rosuvastatin patients and 37% (95% CI 15–65) of rosuvastatin-placebo patients discontinued the study drug. A major cardiovascular complication occurred at 30 days in 1 TXA and 6 TXA-placebo patients, and 1 rosuvastatin and no rosuvastatin-placebo patients.

Conclusions

Our pilot study supports the feasibility of a perioperative TXA trial in noncardiac surgery. Feasibility of a perioperative rosuvastatin trial is uncertain because of a high prevalence of statin use in the target population and concerns about compliance.

Trial registration

ClinicalTrials.govNCT02546648.

Critical limb ischemia: Current and novel therapeutic strategies

Critical limb ischemia (CLI) is the advanced stage of peripheral artery disease spectrum and is defined by limb pain or impending limb loss because of compromised blood flow to the affected extremity. Current conventional therapies for CLI include amputation, bypass surgery, endovascular therapy, and pharmacological approaches. Although these conventional therapeutic strategies still remain as the mainstay of treatments for CLI, novel and promising therapeutic approaches such as proangiogenic gene/protein therapies and stem cell-based therapies have emerged to overcome, at least partially, the limitations and disadvantages of current conventional therapeutic approaches. Such novel CLI treatment options may become even more effective when other complementary approaches such as utilizing proper bioscaffolds are used to increase the survival and engraftment of delivered genes and stem cells. Therefore, herein, we address the benefits and disadvantages of current therapeutic strategies for CLI treatment and summarize the novel and promising therapeutic approaches for CLI treatment. Our analyses also suggest that these novel CLI therapeutic strategies show considerable advantages to be used when current conventional methods have failed for CLI treatment.

Comparison of outcomes after carotid endarterectomy between type 2 diabetic and non-diabetic patients with significant carotid stenosis

BACKGROUND

We aimed to compare early and late outcomes after carotid endarterectomy (CEA) between Korean type 2 diabetic and non-diabetic patients and to investigate the impact of diabetes on the overall incidence of cardiovascular events after CEA.

METHODS

We retrospectively analyzed 675 CEAs, which were performed on 613 patients with significant carotid stenosis between January 2007 and December 2014. The CEAs were divided into a type 2 diabetes mellitus (DM) group (n = 265, 39.3%) and a non-DM group (n = 410, 60.7%). The study outcomes included the incidence of major adverse events (MAEs), defined as fatal or nonfatal stroke or myocardial infarction or all-cause mortality, during the perioperative period and within 4 years after CEA.

RESULTS

Patients in the DM and non-DM groups did not differ significantly in the incidence of MAEs or any of the individual MAE manifestations during the perioperative period. However, within 4 years after CEA, the difference in the MAE incidence was significantly greater in the DM group (P = 0.040). Analysis of the individual MAE manifestations indicated a significantly higher risk of stroke in the DM group (P = 0.006). Multivariate analysis indicated that diabetes was not associated with MAEs or individual MAE manifestations during the perioperative period, whereas within 4 years after CEA, diabetes was an independent risk factor for MAEs overall (hazard ratio [HR], 1.62; 95% confidence interval [CI] 1.06-2.48; P = 0.026) and stroke (HR, 2.55; 95% CI 1.20-5.41; P = 0.015) in particular.

CONCLUSIONS

Diabetic patients were not at greater risk of perioperative MAEs after CEA; however, the risk of late MAE occurrence was significantly greater in these patients. Within 4 years after CEA, DM was an independent risk factor for the occurrence of MAEs overall and stroke in particular.

Association between statin use and perioperative mortality after aortobifemoral bypass in patients with aortoiliac occlusive disease

OBJECTIVE

The benefit of statins in reducing perioperative cardiovascular events in patients undergoing suprainguinal bypass is still controversial. The purpose of this study was to evaluate the association between statin use and perioperative mortality in patients undergoing aortobifemoral bypass (ABFB) for aortoiliac occlusive disease.

METHODS

We retrospectively analyzed all patients who had ABFB in the American College of Surgeons National Surgical Quality Improvement Program data set from 2011 to 2016. Univariable (t-test, χ² test, or Fisher exact test) and multivariable logistic regression analyses were used to compare patients' characteristics and the primary outcome (30-day mortality) between statin users and nonstatin users. Propensity score matching between statin users and nonusers was also performed on the basis of variables that were different between the two groups.

RESULTS

A total of 4445 patients underwent ABFB. Of those, 3032 (68.2%) were taking statins. Compared with nonstatin users, statins users were older (median [interquartile range], 67 years [59-74 years] vs 63 years [56-72 years]; P < .01) and more likely to be diabetic (31% vs 16%) and hypertensive (84% vs 63%) and to have a history of chronic obstructive pulmonary disease (20% vs 17%; all P < .05). Statin users had lower rates of 30-day mortality (3.4% vs 4.7%; P = .03) and renal complications (2.5% vs 3.7%; P = .04) compared with nonstatin users. After adjustment for patients' demographics (age, sex, race), comorbidities (diabetes, hypertension, congestive heart failure, chronic obstructive pulmonary disease, chronic kidney disease, dialysis, bleeding disorder), smoking, clinical presentation (claudication vs critical limb ischemia), and elective surgery status, statin use was associated with 32% reduction in 30-day mortality (odds ratio, 0.68; 95% confidence interval, 0.47-0.96; P = .03). Propensity score matching showed similar results (odds ratio, 0.63; 95% confidence interval, 0.41-0.95; P = .03).

CONCLUSIONS

This is the largest study to date demonstrating an association between preoperative statin use and lower 30-day mortality after ABFB for aortoiliac occlusive disease. This study highlights an area of potential quality improvement as one-third of the patients undergoing this procedure are not receiving statins.

Prevention of post-operative complications by using a HMG-CoA reductase inhibitor in patients undergoing one-lung ventilation for non-cardiac surgery: study protocol for a randomised controlled trial

Background

Postoperative pulmonary complications (PPC) and peri-operative myocardial infarction (MI) have a significant impact on the long-term mortality of surgical patients. Patients undergoing one-lung ventilation (OLV) for surgery are at a high risk of developing these complications. These complications could be associated with intensive care unit (ICU) admissions and longer hospital stay with associated resource and economic burden. Simvastatin, a HMG-CoA reductase enzyme inhibitor has been shown to have pleiotropic anti-inflammatory effects as well as being endothelial protective. The benefits of statins have been shown in various observational studies and in small proof-of-concept studies. There is an urgent need for a well-designed, large clinical trial powered to detect clinical outcomes. The Prevention HARP 2 trial will test the hypothesis ‘simvastatin 80 mg when compared to placebo will reduce cardiac and pulmonary complications in patients undergoing elective oesophagectomy, lobectomy or pneumonectomy’.

Methods/design

The Prevention HARP 2 trial is a UK multi-centre, randomised, double-blind, placebo-controlled trial. Adult patients undergoing elective oesophagectomy, lobectomy or pneumonectomy will be eligible. Patients who are already on statins will be excluded from this trial. Patients will be randomised to receive simvastatin 80 mg or matched placebo for 4 days pre surgery and for up to 7 days post surgery. The primary outcome is a composite outcome of PPC and MI within 7 days post surgery. Various secondary outcome measures including clinical outcomes, safety outcomes and health economic outcomes will be collected. The study aims to recruit 452 patients in total across 12 UK sites.

Discussion

The results of the Prevention HARP 2 trial should add to our understanding of the benefits of peri-operative statins and influence clinical decision-making. Analysis of blood and urine samples from the patients will provide insight into the mechanism of simvastatin action.

Trial registration

International Standard Randomised Controlled Trials registry, ID: ISRCTN48095567. Registered on 11 November 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3078-5) contains supplementary material, which is available to authorized users.

Modulation of Ion Channels in the Superior Cervical Ganglion Neurons by Myocardial Ischemia and Fluvastatin Treatment

Background: The superior cervical ganglion (SCG) of the autonomic nervous system plays an important role in different cardiovascular diseases. In this study, we investigated the effects of ischemia and fluvastatin treatment on the ion channel characteristics of SCG neurons in a rabbit myocardial ischemia (MI) model.

Methods: MI was induced by abdominal subcutaneous injections of isoproterenol (ISO). The properties of the delayed rectifier potassium channel current (I_K), sodium channel current (I_Na), and action potential (APs) on isolated SCG neurons in the control, MI-7d, MI-14d, fluvastatin-7d (fluvastatin pretreated 14 days and treated 7 days after ISO-induced MI), and fluvastatin-14d (fluvastatin pretreated 14 days and treated 14 days after ISO-induced MI) groups were studied. In addition, the RNA expressions of KCNQ3 and SCN9A in the SCG tissue were determined by performing real-time PCR. Intracellular calcium concentration was monitored using laser scanning confocal microscopy.

Results: Compared with the control group, the current amplitude of I_K and I_Na were increased in the MI-7d and MI-14d groups. KCNQ3 RNA (corresponding to channel proteins of I_K) expression and SCN9A RNA (corresponding to channel proteins of I_Na) expression were also increased in MI groups. Activation and inactivation curves for I_Na in the two MI groups shifted negatively compared with the control group. These changes were reversed by fluvastatin treatment. Intracellular calcium concentration in SCG neurons was not altered significantly by MI or fluvastatin treatment. By contrast, increased AP amplitude and shortened APD₉₀ were observed in the MI-7d and MI-14d groups. These changes were reversed in the fluvastatin-treated MI group.

Conclusion: Fluvastatin treatment partly reversed the characteristics of SCG neurons in MI. The ion channel of SCG neurons could be one of the potential targets of fluvastatin in treating coronary heart diseases.

Effects of perioperative statins on patient outcomes after noncardiac surgery: a meta-analysis

BACKGROUND

Cardiovascular complications are strongly correlated with a higher risk of mortality during follow-up after noncardiac surgery. However, controversy remains regarding whether perioperative administration of hydroxymethylglutaryl-CoA reductase inhibitors (statins) has a beneficial effect on patient outcomes.

OBJECTIVE

We performed a meta-analysis to validate the hypothesis that perioperative statins improve patient outcomes after noncardiac surgery.

METHODS

Electronic databases (PubMed, Web of Science, EMBASE, and the Cochrane Library) were searched for randomized controlled trials (RCTs) published up to 10 November 2017. RCTs were eligible for inclusion if they compared perioperative statin treatment with control treatment in patients scheduled for noncardiac surgery and reported data pertaining to clinical outcomes.

RESULTS

Twelve RCTs involving 4707 patients (2371 in the perioperative statin group and 2336 in the control group) were ultimately included in this meta-analysis. The incidences of postoperative myocardial infarction, composite of death/myocardial infarction/stroke and new cases of atrial fibrillation were all lower in patients treated with statins than in control group patients, as shown by the fixed-effects model (odds ratio (OR) = 0.460, 95% confidence interval (CI) = 0.324-0.653, p = 0 for myocardial infarction; OR = 0.617, 95% CI = 0.476-0.801, p = 0 for composite of death/myocardial infarction/stroke; OR = 0.406, 95% CI = 0.247-0.666, p = 0 for new atrial fibrillation). No significant differences in the incidences of stroke or transient ischemic attack, all-cause mortality and cardiovascular mortality were observed between the statin and control arms.

CONCLUSIONS

This meta-analysis supports the hypothesis that perioperative statins effectively reduce the incidences of postoperative myocardial infarction, composite of death/myocardial infarction/stroke and new cases of atrial fibrillation in patients undergoing noncardiac surgery. Key Messages Cardiovascular complications are strongly correlated with a higher risk of mortality during follow-up after noncardiac surgery. We performed a meta-analysis to confirm the hypothesis that perioperative statins improve patient outcomes after noncardiac surgery.

Statin therapy improved long-term prognosis in patients with major non-cardiac vascular surgeries: a systematic review and meta-analysis

OBJECTIVE

To investigate whether statin intervention will improve the long-term prognosis of patients undergoing major non-cardiac vascular surgeries.

METHODS

Major database searches for clinical trials enrolling patients undergoing major non-cardiac vascular surgeries, including lower limb revascularization, carotid artery surgeries, arteriovenous fistula, and aortic surgeries, were performed. Subgroup analyses, stratified by surgical types or study types, were employed to obtain statistical results regarding survival, patency rates, amputation, and cardiovascular and stroke events. Odds ratio (ORs) and 95% confidence intervals (CIs) were calculated by Review Manager 5.3. Sensitivity analysis, publication bias and meta-regression were conducted by Stata 14.0.

RESULTS

In total, 34 observational studies, 8 prospective cohort studies and 4 randomized controlled clinical trials (RCTs) were enrolled in the present analysis. It was demonstrated that statin usage improved all-cause mortality in lower limb, carotid, aortic and mixed types of vascular surgery subgroups compared with those in which statins were not used. Additionally, the employment of statins efficiently enhanced the primary and secondary patency rates and significantly decreased the amputation rates in the lower limb revascularization subgroup. Furthermore, for other complications, statin intervention decreased cardiovascular events in mixed types of vascular surgeries and stroke incidence in the carotid surgery subgroup. No significant publication bias was observed. The meta-regression results showed that the morbidity of cardiovascular disease or the use of aspirin might affect the overall estimates in several subgroups.

CONCLUSIONS

This meta-analysis demonstrated that statin therapy was associated with improved survival rates and patency rates and with reduced cardiovascular or stroke morbidities in patients who underwent non-cardiac vascular surgeries.

Current status of the treatment of infrarenal abdominal aortic aneurysms

Aortic aneurysms are the 13^th leading cause of death in the United States. While aneurysms can occur along the entire length of the aorta, the infrarenal location is the most common. Targeted ultrasound screening has been found to be an effective and economical means of preventing aortic aneurysm rupture. The indication for repair includes either symptomatic aneurysms or aneurysms with a diameter greater than 5.4 cm. Treatment options for the repair of infrarenal aortic aneurysms are open surgical repair (OSR) and endovascular aneurysm repair (EVAR). Currently, EVAR is the primary treatment method for the repair of infrarenal aortic aneurysms due to improved short-term morbidity and mortality outcomes. This article is intended to review the current status of the management of infrarenal abdominal aortic aneurysms (AAA).

Postoperative Myocardial Injury and Inflammation Is Not Blunted by a Trial of Atorvastatin in Orthopedic Surgery Patients

BACKGROUND

Orthopedic patients are at risk for adverse postoperative cardiovascular outcomes.

QUESTIONS/PURPOSES

This pilot randomized controlled trial (RCT) of atorvastatin vs. placebo in orthopedic surgery patients was performed in order to assess: (1) the prevalence of perioperative myocardial injury; (2) the effect of atorvastatin on perioperative inflammation; and (3) the feasibility of performing a large RCT of statin therapy in orthopedic patients.

METHODS

Hip fracture (hip Fx) and total hip and knee replacement (THR and TKR) patients were randomized 1:1 to atorvastatin 40 mg daily vs. placebo, starting preoperatively and continuing until postoperative day (POD) 45. High-sensitivity cardiac troponin I (hs-cTnI), high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) were measured preoperatively and on POD 2. Patients were monitored for adverse events until POD 90.

RESULTS

Five hundred fifty-six patients were screened, 22 were recruited (4 hip Fx, 11 THR, 7 TKR), and 2 withdrew. Most (80%) had detectable hs-cTnI (> 1.1 pg/mL) preoperatively. Twenty percent had a perioperative rise in hs-cTnI (≥ 10 pg/mL), which was not blunted by atorvastatin. Hs-CRP rose in 19/20 patients, and IL-6 rose in all patients. However, atorvastatin did not blunt the rise in these inflammatory biomarkers. On POD 2, IL-6 and hs-cTnI levels correlated (ρ = 0.59, p = 0.02). Recruitment was limited by the high prevalence of statin use in the screened population and a high prevalence of exclusions among hip fracture patients.

CONCLUSION

Perioperative myocardial injury and inflammation are common in orthopedic patients and do not appear to be reduced in those randomized to atorvastatin.

TRIAL REGISTRATION

NCT02197065.

Beneficial effect of statins on total mortality in abdominal aortic aneurysm (AAA) repair

In this single center, retrospective cohort study we wished to compare early and total mortality for all patients treated for abdominal aortic aneurysms (AAA) with open surgery who were taking statins compared to those who were not. A cohort of 640 patients with AAA was treated with open surgery between 1999 and 2012. Patients were consecutively recruited from a source population of 390,000; 21.3% were female, and the median age was 73 years. The median follow-up was 3.93 years, with an interquartile range of 1.79–6.58 years. The total follow-up was 2855 patient-years. An explanatory strategy was used. The propensity score (PS) was implemented to control for selection bias and confounders. The crude effect of statin use showed a 78% reduction of the 30-day mortality. A stratified analysis using the Mantel–Haenszel method on quintiles of the PS gave an adjusted effect of the odds ratio equal to 0.43 (95% CI: 0.18–0.96), indicating a 57% reduction of the 30-day mortality for statin users. The adjusted rate ratio was 0.62 (95% CI: 0.45–0.83), indicating a reduction of long-term mortality of 38% for statin users compared to non-users for a median follow-up of 3.93 years. This retrospective cohort study showed a significant beneficial effect of statin use on early and long-term survival for patients treated with open surgery. To be conclusive, our results need to be replicated by a randomized clinical trial.

Magnitude and direction of missing confounders had different consequences on treatment effect estimation in propensity score analysis

OBJECTIVE

Propensity score (PS) analysis allows an unbiased estimate of treatment effects but assumes that all confounders are measured. We assessed the impact of omitting confounders from a PS analysis on clinical decision making.

STUDY DESIGN AND SETTING

We conducted Monte Carlo simulations on hypothetical observational studies based on virtual populations and on the population from a large randomized trial (CRASH-2). In both series of simulations, PS analysis was conducted with all confounders and with omitted confounders, which were defined to have different strengths of association with the outcome and treatment exposure. After inverse probability of treatment weighting, we calculated the absolute risk differences and numbers needed to treat (NNT).

RESULTS

In both series of simulations, omitting a confounder that was moderately associated with the outcome and exposure led to negligible bias on the NNT scale. The bias induced by omitting strongly positive confounding variables remained less than 15 patients to treat. Major bias and reversed effects were found only when omitting highly prevalent, strongly negative confounders that were similarly associated with the outcome and exposure with odds ratios greater than 4.00 (or <0.25). This omission was accompanied by a substantial decrease in analysis power.

CONCLUSION

The omission of strongly negative confounding variables from a PS analysis can lead to incorrect clinical decision making. However, omitting these variables also decreases the analysis power, which may prevent the reporting of significant but misleading effects.

Effects of perioperative statin use on cardiovascular complications in patients submitted to non-cardiac surgery: protocol for a systematic review, meta-analysis, and trial sequential analysis

BACKGROUND

Preliminary evidence suggests statins may reduce major perioperative vascular events. However, evidence is limited to observational studies, underpowered trials, and non-comprehensive systematic reviews. This review aims to assess the effects of perioperative statin use on cardiovascular complications in patients submitted to non-cardiac surgery.

METHODS

We will search MEDLINE/PubMed, EMBASE, LILACS, CENTRAL, Web of Science, and CINAHL for randomized controlled trials assessing the effects of perioperative statin use in adults undergoing non-cardiac surgery and reporting cardiovascular complications. For patients already using statins for hyperlipidemia, a preoperative loading dose of statin is required in the experimental group. We will place no language or publication restriction on our search. Teams of two reviewers will independently assess eligibility and risk of bias, and will extract data from the included trials. Our primary outcome is a combination of cardiovascular mortality or non-fatal myocardial infarction. We will also assess the following outcomes: individual components of the primary outcome, all-cause mortality, total myocardial infarction, elevated troponin in the first seven postoperative days, total stroke, total venous thromboembolism, postoperative atrial fibrillation, elevation of creatine phosphokinase or liver enzymes, and rates of myalgia or rhabdomyolysis. We will conduct meta-analyses using random-effects model and will use trial sequential analysis to establish monitoring boundaries to limit global type I error due to repetitive testing for our primary outcome. We will rate the quality of evidence using the GRADE system.

DISCUSSION

The results of this systematic review may help to inform clinical practice and also the design of future large-scale randomized trials.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016035987.

Dose-Dependent Effect of Statin Pretreatment on Preventing the Periprocedural Complications of Carotid Artery Stenting

BACKGROUND AND PURPOSE

We investigated whether statin pretreatment can dose dependently reduce periprocedural complications in patients undergoing carotid artery stenting because of symptomatic carotid artery stenosis.

METHODS

We enrolled a consecutive series of 397 symptomatic carotid artery stenosis (≥50% stenosis on conventional angiography) treated with carotid artery stenting at 2 tertiary university hospitals over a decade. Definition of periprocedural complications included any stroke, myocardial infarction, and death within 1 month after or during the procedure. Statin pretreatment was divided into 3 categories according to the atorvastatin equivalent dose: none (n=158; 39.8%), standard dose (<40 mg of atorvastatin, n=155; 39.0%), and high dose (≥40 mg; n=84; 21.2%). A multivariable logistic regression analysis with the generalized estimating equation method was used to investigate independent factors in periprocedural complications.

RESULTS

The patients' mean age was 68.7 years (81.6% men). The periprocedural complication rates across the 3 categories of statin use were 12.0%, 4.5%, and 1.2%. After adjustment, a change in the atorvastatin dose category was associated with reduction in the odds of periprocedural complications for each change in dose category (standard-dose statin: odds ratio, 0.24; 95% confidence interval, 0.07-0.81; high-dose statin: odds ratio, 0.11; 95% confidence interval, 0.01-0.96; P for trend=0.01). Administration of antiplatelet drugs was also an independent factor in periprocedural complications (OR, 0.18; 95% CI, 0.05-0.69).

CONCLUSIONS

This study shows that statin pretreatment may reduce the incidence of periprocedural complications dose dependently in patients with symptomatic carotid artery stenting.

Risk Factors for Suboptimal Utilization of Statins and Antiplatelet Therapy in Patients Undergoing Revascularization for Symptomatic Peripheral Arterial Disease

BACKGROUND

The objective of this study was to identify risk factors for suboptimal medical therapy (defined as reported antiplatelet and statin use) among patients undergoing lower extremity bypass (LEB) and peripheral vascular interventions (PVIs) for symptomatic peripheral arterial disease (PAD).

METHODS

The Vascular Study Group of Greater New York (VSGGNY) database was used to identify all patients undergoing PVI or LEB for PAD (2011-2013). Bivariate analyses were performed to identify characteristics of patients who were not prescribed statins and/or antiplatelet agents before revascularization. Multivariate relative risk regression models were developed to identify patients at risk for suboptimal therapy, with regards to antiplatelet and statin therapy.

RESULTS

About 1,030 patients underwent endovascular therapy (n = 822; 80%) or surgical bypass (n = 208; 20%) for symptomatic PAD (57.2% claudication; 15% rest pain and 27.8% tissue loss). Overall, preoperative statin use was observed in 59%. Preoperative antiplatelet therapy was observed in 79% of patients. Bivariate analysis revealed comparatively reduced statin use among patients without other cardiovascular risk factors including hypertension (63% vs. 39.3%; P < 0.0001) and coronary artery disease (CAD) with or without prior cardiac revascularization (coronary artery bypass grafting [CABG]/percutaneous coronary intervention [PCI]; 75.2% vs. 47.4%; P < 0.0001). Multivariate relative risk regression confirmed higher rates of statin use among patients with other cardiovascular risk factors including hypertension (1.14 [1.02-1.27]; P = 0.02) and CAD with prior CABG/PCI (1.22 [1.13-1.31]; P < 0.0001). Reduced statin use was observed in patients over 80 years old. (0.92 [0.84-0.1.0]; P = 0.059). By multivariate regression, antiplatelet therapy use was associated with CAD and/or prior CABG/PCI (1.11 [1.04-1.17]; P = 0.0015) and prior peripheral revascularization (1.07 [1.01-1.13]; P = 0.03).

CONCLUSIONS

Patients with symptomatic PAD, but without an antecedent cardiovascular history, are less likely to be optimally managed with statins and antiplatelet therapy preoperatively. Given the established role of these medications in the optimal medical management of patients with PAD, this presents an opportunity for improvement in the overall vascular care of patients undergoing intervention for symptomatic PAD at VSGGNY centers.

Double-adjustment in propensity score matching analysis: choosing a threshold for considering residual imbalance

BACKGROUND

Double-adjustment can be used to remove confounding if imbalance exists after propensity score (PS) matching. However, it is not always possible to include all covariates in adjustment. We aimed to find the optimal imbalance threshold for entering covariates into regression.

METHODS

We conducted a series of Monte Carlo simulations on virtual populations of 5,000 subjects. We performed PS 1:1 nearest-neighbor matching on each sample. We calculated standardized mean differences across groups to detect any remaining imbalance in the matched samples. We examined 25 thresholds (from 0.01 to 0.25, stepwise 0.01) for considering residual imbalance. The treatment effect was estimated using logistic regression that contained only those covariates considered to be unbalanced by these thresholds.

RESULTS

We showed that regression adjustment could dramatically remove residual confounding bias when it included all of the covariates with a standardized difference greater than 0.10. The additional benefit was negligible when we also adjusted for covariates with less imbalance. We found that the mean squared error of the estimates was minimized under the same conditions.

CONCLUSION

If covariate balance is not achieved, we recommend reiterating PS modeling until standardized differences below 0.10 are achieved on most covariates. In case of remaining imbalance, a double adjustment might be worth considering.

Pleiotropic effects of statins in the perioperative setting

Statins belong to a specific group of drugs that have been described for their ability to control hyperlipidemia as well as for other pleiotropic effects such as improving vascular endothelial function, inhibition of oxidative stress pathways, and anti-inflammatory actions. Accumulating clinical evidence strongly suggests that statins also have a beneficial effect on perioperative morbidity and mortality. Therefore, this review aims to present all recent and pooled data on statin treatment in the perioperative setting as well as to highlight considerations regarding their indications and therapeutic application.

Simple randomization did not protect against bias in smaller trials

OBJECTIVES

By removing systematic differences across treatment groups, simple randomization is assumed to protect against bias. However, random differences may remain if the sample size is insufficiently large. We sought to determine the minimal sample size required to eliminate random differences, thereby allowing an unbiased estimation of the treatment effect.

STUDY DESIGN AND SETTING

We reanalyzed two published multicenter, large, and simple trials: the International Stroke Trial (IST) and the Coronary Artery Bypass Grafting (CABG) Off- or On-Pump Revascularization Study (CORONARY). We reiterated 1,000 times the analysis originally reported by the investigators in random samples of varying size. We measured the covariates balance across the treatment arms. We estimated the effect of aspirin and heparin on death or dependency at 30 days after stroke (IST), and the effect of off-pump CABG on a composite primary outcome of death, nonfatal stroke, nonfatal myocardial infarction, or new renal failure requiring dialysis at 30 days (CORONARY). In addition, we conducted a series of Monte Carlo simulations of randomized trials to supplement these analyses.

RESULTS

Randomization removes random differences between treatment groups when including at least 1,000 participants, thereby resulting in minimal bias in effects estimation. Later, substantial bias is observed. In a short review, we show such an enrollment is achieved in 41.5% of phase 3 trials published in the highest impact medical journals.

CONCLUSIONS

Conclusions drawn from completely randomized trials enrolling a few participants may not be reliable. In these circumstances, alternatives such as minimization or blocking should be considered for allocating the treatment.