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

Asymmetric dimethylarginine predicts perioperative cardiovascular complications in patients undergoing medium-to-high risk non-cardiac surgery

Objectives

Perioperative cardiovascular events remain an important factor that affects surgery outcome. We assessed if asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, predicts perioperative risk, and if pre-operative supplementation with L-arginine/L-citrulline improves the plasma L-arginine/ADMA ratio.

Methods

In this prospective study, planned thoracic and/or abdominal surgery patients were randomized to receive L-arginine/L-citrulline (5 g/day) or placebo 1 to 5 days before surgery. We measured perioperative plasma ADMA and L-arginine levels. The primary outcome was a 30-day combined cardiovascular endpoint.

Results

Among 269 patients, 23 (8.6%) experienced a major adverse cardiovascular event. ADMA and C-reactive protein were significantly associated with the incidence of cardiovascular complications in the multivariable-adjusted analysis. The L-arginine plasma concentration was significantly higher on the day of surgery with L-arginine/L-citrulline supplementation compared with placebo. In patients with high pre-operative ADMA, there was a non-significant trend towards reduced incidence of the primary endpoint with L-arginine/L-citrulline supplementation (six vs. nine events).

Conclusions

ADMA is a predictor of major adverse cardiovascular complications in the perioperative period for patients who are undergoing major abdominal and/or thoracic surgery. Supplementation with L-arginine/L-citrulline increased the L-arginine plasma concentration, enhanced the L-arginine/ADMA ratio, and induced a trend towards fewer perioperative events.

[Atrial Fibrillation After Coronary Artery Bypass Surgery: Risk Factors, Prevention and Treatment]

This review focuses on the issue of atrial fibrillation (AF) following coronary bypass surgery in patients with ischemic heart disease. Risk factors of this complication are discussed in detail. The authors addressed the effect of diabetes mellitus on development of postoperative AF. Data on current methods for prevention and treatment of AF are provided.

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.

Statins in the perioperative period

In this review, we discuss clinical evidence-based data regarding the potential benefit of statin therapy in the perioperative period of non-cardiac surgery. Results from meta-analyses of prospective observational studies have provided conflicting evidence. Moreover, comparison among studies is complicated by varying data sources, outcome definitions, types of surgery, and preoperative versus perioperative statin therapy. However, results of two recent large prospective cohort studies showed that statin use on the day of or the day after non-cardiac surgery (or both) is associated with lower 30-day all-cause mortality and reduction in a variety of postoperative complications, predominantly cardiac, compared with non-use during this period. There is a paucity of data from randomized controlled trials assessing the benefit of statin therapy in non-cardiac surgery. No randomized controlled trials have shown that initiating a statin in statin-naïve patients may reduce the risk of cardiovascular complications in non-cardiac surgeries. One randomized clinical trial demonstrated that the use of a preoperative statin in patients with stable coronary heart disease treated with long-term statin therapy had a significant reduction in the incidence of myocardial necrosis and major adverse cardiovascular events after non-cardiac surgery. In conclusion, it is important that all health-care professionals involved in the care of the surgical patient emphasize the need to resume statin therapy, particularly in patients with established atherosclerotic cardiovascular disease. However, initiating a statin in statin-naïve patients undergoing non-cardiac surgery needs more evidence-based data.

Preoperative chronic beta-blocker prescription in elderly patients as a risk factor for postoperative mortality stratified by preoperative blood pressure: a cohort study

BACKGROUND

Recent data suggest that beta blockers are associated with increased perioperative risk in hypertensive patients. We investigated whether beta blockers were associated with an increased risk in elderly patients with raised preoperative arterial blood pressure.

METHODS

We conducted a propensity-score-matched cohort study of primary care data from the UK Clinical Practice Research Datalink (2004-13), including 84 633 patients aged 65 yr or over. Conditional logistic regression models, including factors that were significantly associated with the outcome, were constructed for 30-day mortality after elective noncardiac surgery. The effects of beta blockers (primary outcome), renin-angiotensin system (RAS) inhibitors, calcium-channel blockers, thiazides, loop diuretics, and statins were investigated at systolic and diastolic arterial pressure thresholds.

RESULTS

Beta blockers were associated with increased odds of postoperative 30-day mortality in patients with systolic hypertension (defined as systolic BP >140 mm Hg; adjusted odds ratio [aOR]: 1.92; 95% confidence interval [CI]: 1.05-3.51). After excluding patients for whom prior data suggest benefit from perioperative beta blockade (patients with prior myocardial infarction or heart failure), rather than adjusting for them, the point estimate shifted slightly (aOR: 2.06; 95% CI: 1.09-3.89). Compared with no use, statins (aOR: 0.35; 95% CI: 0.17-0.75) and thiazides (aOR: 0.28; 95% CI: 0.10-0.78) were associated with lower mortality in patients with systolic hypertension.

CONCLUSIONS

These data suggest that the safety of perioperative beta blockers may be influenced by preoperative blood pressure thresholds. A randomised controlled trial of beta-blocker withdrawal, in select populations, is required to identify a causal relationship.

Medical therapy for atherosclerotic cardiovascular disease in patients with myocardial injury after non-cardiac surgery

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) is a common post-operative cardiovascular complication and is associated with short and long-term mortality. The objective of this study was to describe the contemporary management of patients with and without MINS after total joint and spine orthopedic surgery at a large urban health system in the United States.

METHODS

Adults admitted for total joint and major spine surgery from January 2013 through December 2015 with ≥1 cardiac troponin (cTn) measurement during their hospitalization were identified. MINS was defined by a peak cTn above the 99th percentile of the upper reference limit. Demographics, medical comorbidities, and admission and discharge medications were reviewed for all patients.

RESULTS

A total of 2561 patients underwent 2798 orthopedic surgeries, and 236 cases of MINS were identified. Patients with MINS were older (71.9 ± 10.9 vs. 67.0 ± 10.0, p < 0.001) and more likely to have cardiovascular risk factors, including hypertension, chronic kidney disease, prior stroke, coronary artery disease, prior MI, and a history of heart failure. Among patients with MINS, only 112 (47.5%) were discharged on a combination of aspirin and statin. Patients with MINS were more likely to be prescribed a statin (154 [65.3%] vs. 1463 [57.1%], p = 0.018), beta-blocker (147 [62.3%] vs. 1194 [46.6%], p < 0.001), and oral anticoagulation (65 [27.5%] vs. 436 [17.0%], p < 0.001) than patients without MINS.

CONCLUSIONS

The proportion of patients with MINS who were prescribed medical therapy for atherosclerotic cardiovascular disease was low. Additional efforts to determine optimal management of MINS are warranted.

Perioperative statin therapy in cardiac and non-cardiac surgery: a systematic review and meta-analysis of randomized controlled trials

Background

The effects of perioperative statin therapy on clinical outcome after cardiac or non-cardiac surgery are controversial. We aimed to assess the association between perioperative statin therapy and postoperative outcome.

Methods

Electronic databases were searched up to May 1, 2018, for randomized controlled trials of perioperative statin therapy versus placebo or no treatment in adult cardiac or non-cardiac surgery. Postoperative outcomes were: myocardial infarction, stroke, acute kidney injury (AKI), and mortality. We calculated risk ratio (RR) or odds ratio (OR) and 95% confidence interval (CI) using fixed-effects meta-analyses. We performed meta-regression and subgroup analyses to assess the possible influence of statin therapy regimen on clinical outcomes and trial sequential analysis to evaluate the risk of random errors and futility.

Results

We included data from 35 RCTs involving 8200 patients. Perioperative statin therapy was associated with lower incidence of postoperative myocardial infarction in non-cardiac surgery (OR = 0.44 [95% CI 0.30–0.64], p < 0.0001), but not in cardiac surgery (OR = 0.93 [95% CI 0.70–1.24], p = 0.61) (p_subgroup = 0.002). Higher incidence of AKI was present in cardiac surgery patients receiving perioperative statins (RR = 1.15 [95% CI 1.00–1.31], p = 0.05), nonetheless not in non-cardiac surgery (RR = 1.52 [95% CI 0.71–3.26], p = 0.28) (p_subgroup = 0.47). No difference in postoperative stroke and mortality was present in either cardiac or non-cardiac surgery. However, low risk of bias trials performed in cardiac surgery showed a higher mortality with statins versus placebo (OR = 3.71 [95% CI 1.03–13.34], p = 0.04). Subgroup and meta-regression analyses failed to find possible relationships between length of statin regimens and clinical outcomes. Trial sequential analysis suggested no firm conclusions on the topic.

Conclusions

Perioperative statins appear to be protective against postoperative myocardial infarction in non-cardiac surgery and associated with higher AKI in cardiac surgery. Possible positive or even negative effects on mortality could not be excluded and merits further investigations. Currently, no randomized evidence supports the systematic administration of statins in surgical patients.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0441-3) contains supplementary material, which is available to authorized users.

Statin intensity and postoperative mortality following open repair of intact abdominal aortic aneurysm

Background

There is a lack of evidence for the association between intensive statin therapy and outcomes following vascular surgery. The aim of this study was to evaluate the association between perioperative statin intensity and in-hospital mortality following open abdominal aortic aneurysm (AAA) repair.

Methods

Patients undergoing open AAA repair between 2009 and 2015 were identified from the Premier Healthcare Database. Statin use was classified into low, moderate and high intensity, based on American College of Cardiology/American Heart Association guidelines. Supratherapeutic intensity was defined as doses higher than the recommended guidelines. Multivariable logistic regression analyses were undertaken to assess the association between statin intensity and postoperative major adverse events and in-hospital mortality.

Results

Of 6497 patients undergoing open AAA repair, 3217 (49·5 per cent) received perioperative statin. Statin users were more likely to present with three or more co-morbidities than non-users (26·5 versus 21·8 per cent; P < 0·001). Unadjusted postoperative mortality was significantly lower in statin users (2·6 versus 6·3 per cent; P < 0·001); however, there was no difference in the risk of developing major adverse events. Multivariable analysis showed that statin use was associated with lower odds of death (odds ratio 0·41, 95 per cent c.i. 0·31 to 0·54). Moderate, high and supratherapeutic statin intensities were not associated with lower odds of death or major adverse events compared with low-intensity statin therapy.

Conclusion

Statin use is associated with lower odds of death in hospital following open AAA repair. High-intensity statins were not associated with lower morbidity or mortality.

Systematic review and meta-analysis of perioperative and long-term outcomes in patients receiving statin therapy before carotid endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) is associated with perioperative stroke and mortality in a minority of cases. The aim of this systematic review and meta-analysis was to investigate the effect of pre-operative statins on perioperative outcomes in patients undergoing CEA for internal carotid artery (ICA) stenosis.

METHODS

A systematic review of PubMed, Medline, and the Cochrane Database of Systematic Reviews was performed. Studies were included which reported perioperative stroke and/or survival outcomes following CEA for ICA stenosis and compared patients who were and were not taking pre-operative statins. Relevant data were extracted and pooled using meta-analysis.

RESULTS

Seven studies met the inclusion criteria, comprising 21,387 patients. A total of 68.9% (14,976) were administered statins and 31.1% (6657) were statin-free. Pre-operative statin use was higher in patients with a history of cardiac disease (12.2 vs. 23.6% in the statin-free group), diabetes (31.6 vs. 25.1% in the statin-free group), and hypertension (83.5 vs. 72.2% in the statin-free group), while a greater proportion of statin-free patients had symptomatic disease (44.9 vs. 55.5% in the statin-free group). Statins were associated with reduced perioperative stroke in all patients (OR 0.57; 95% CI 0.34-0.95; p = 0.03) and in symptomatic patients (OR 0.57; 95% CI 0.35-0.93; p = 0.03). A trend towards lower perioperative mortality (OR 0.54; 95% CI 0.29, 1.03; p = 0.06) and significantly improved overall survival was observed in the statin group (HR 0.69; 95% CI 0.59-0.81; p < 0.001) at a mean follow-up of 62 months (range 27-76 months).

CONCLUSIONS

Administration of statins before CEA is associated with lower rates of perioperative stroke and improved overall survival. Compliance with optimal medical treatment associated with the use of pre-operative statins may limit the clinical significance of these findings. Future investigation to characterize the potential benefit of statin therapy in patients undergoing CEA for ICA stenosis is warranted.

Statin therapy is associated with higher long-term but not perioperative survival after abdominal aortic aneurysm repair

BACKGROUND

Although preoperative and perioperative statin therapy improves postoperative outcomes in several populations, few data examine its association with survival after abdominal aortic aneurysm (AAA) repair. In addition, no data exist regarding the benefits of starting statins in patients with AAA not currently taking them.

METHODS

We performed a registry-based study of all patients undergoing repair of AAAs in the Vascular Quality Initiative between 2003 and 2017 without documented statin intolerance. In our primary analysis, we evaluated the association between preoperative statin therapy and long-term mortality, 30-day mortality, and in-hospital myocardial infarction and stroke. As a secondary analysis, we studied the cohort of patients not taking a statin preoperatively and compared their long-term mortality on the basis of whether they were discharged on a statin. To account for nonrandom assignment to treatment, we constructed propensity scores and applied inverse probability weighting.

RESULTS

We identified 40,452 AAA repairs, of which 37,950 fit our entry criteria (29,257 endovascular and 8693 open). Overall, 25,997 patients (69%) were taking a statin preoperatively, with patients undergoing endovascular aneurysm repair more frequently taking a statin than those undergoing open repair (69% compared with 66%; P < .001). After propensity weighting, preoperative statin therapy was not associated with 30-day death or in-hospital stroke or myocardial infarction. However, patients taking statins preoperatively experienced higher adjusted 1-year (94% vs 90%) and 5-year (85% vs 81%) survival from the date of surgery compared with those who were not (P < .001 overall), although subgroup analysis showed that this applied only to intact or symptomatic aneurysms. Of the 11,941 patients not taking a statin preoperatively and discharged alive, 2910 (24%) started on a statin before discharge. In our secondary analysis of the subset of patients not taking statins preoperatively, those initiated on a statin before discharge experienced higher survival at 1 year (94% vs 91%) and 5 years (89% vs 81%; P < .001 overall) than those who remained off statin therapy, with the greatest absolute long-term survival difference in patients with rupture (87% vs 62%; P < .001 overall).

CONCLUSIONS

Preoperative statin therapy is associated with higher long-term survival but not perioperative mortality and morbidity in patients undergoing AAA repair, and initiating statin therapy in previously statin-naive patients is associated with markedly higher survival. All patients with AAAs without contraindications should receive statin therapy. In patients not taking a statin at the time of AAA repair, clinicians should consider initiating one before discharge.

Continuation versus discontinuation of antiplatelet therapy for bleeding and ischaemic events in adults undergoing non-cardiac surgery

BACKGROUND

Antiplatelet agents are recommended for people with myocardial infarction and acute coronary syndromes, transient ischaemic attack or stroke, and for those in whom coronary stents have been inserted. People who take antiplatelet agents are at increased risk of adverse events when undergoing non-cardiac surgery because of these indications. However, taking antiplatelet therapy also introduces risk to the person undergoing surgery because the likelihood of bleeding is increased. Discontinuing antiplatelet therapy before surgery might reduce this risk but subsequently it might make thrombotic problems, such as myocardial infarction, more likely.

OBJECTIVES

To compare the effects of continuation versus discontinuation for at least five days of antiplatelet therapy on the occurrence of bleeding and ischaemic events in adults undergoing non-cardiac surgery under general, spinal or regional anaesthesia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 1), MEDLINE (1946 to January 2018), and Embase (1974 to January 2018). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized controlled trials of adults who were taking single or dual antiplatelet therapy, for at least two weeks, and were scheduled for elective non-cardiac surgery. Included participants had at least one cardiac risk factor. We planned to include quasi-randomized studies.We excluded people scheduled for minor surgeries under local anaesthetic or sedation in which bleeding that required transfusion or additional surgery was unlikely. We included studies which compared perioperative continuation of antiplatelet therapy versus discontinuation of antiplatelet therapy or versus substitution of antiplatelet therapy with a placebo for at least five days before surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias and synthesized findings. Our primary outcomes were: all-cause mortality at longest follow-up (up to six months); all-cause mortality (up to 30 days). Secondary outcomes included: blood loss requiring transfusion of blood products; blood loss requiring further surgical intervention; risk of ischaemic events. We used GRADE to assess the quality of evidence for each outcome MAIN RESULTS: We included five RCTs with 666 randomized adults. We identified three ongoing studies.All study participants were scheduled for elective general surgery (including abdominal, urological, orthopaedic and gynaecological surgery) under general, spinal or regional anaesthesia. Studies compared continuation of single or dual antiplatelet therapy (aspirin or clopidogrel) with discontinuation of therapy for at least five days before surgery.Three studies reported adequate methods of randomization, and two reported methods to conceal allocation. Three studies were placebo-controlled trials and were at low risk of performance bias, and three studies reported adequate methods to blind outcome assessors to group allocation. Attrition was limited in four studies and two studies had reported prospective registration with clinical trial registers and were at low risk of selective outcome reporting bias.We reported mortality at two time points: the longest follow-up reported by study authors up to six months, and time point reported by study authors up to 30 days. Five studies reported mortality up to six months (of which four studies had a longest follow-up at 30 days, and one study at 90 days) and we found that either continuation or discontinuation of antiplatelet therapy may make little or no difference to mortality up to six months (risk ratio (RR) 1.21, 95% confidence interval (CI) 0.34 to 4.27; 659 participants; low-certainty evidence); the absolute effect is three more deaths per 1000 with continuation of antiplatelets (ranging from eight fewer to 40 more). Combining the four studies with a longest follow-up at 30 days alone showed the same effect estimate, and we found that either continuation or discontinuation of antiplatelet therapy may make little or no difference to mortality at 30 days after surgery (RR 1.21, 95% CI 0.34 to 4.27; 616 participants; low-certainty evidence); the absolute effect is three more deaths per 1000 with continuation of antiplatelets (ranging from nine fewer to 42 more).We found that either continuation or discontinuation of antiplatelet therapy probably makes little or no difference in incidences of blood loss requiring transfusion (RR 1.37, 95% CI 0.83 to 2.26; 368 participants; absolute effect of 42 more participants per 1000 requiring transfusion in the continuation group, ranging from 19 fewer to 119 more; four studies; moderate-certainty evidence); and may make little or no difference in incidences of blood loss requiring additional surgery (RR 1.54, 95% CI 0.31 to 7.58; 368 participants; absolute effect of six more participants per 1000 requiring additional surgery in the continuation group, ranging from seven fewer to 71 more; four studies; low-certainty evidence). We found that either continuation or discontinuation of antiplatelet therapy may make little or no difference to incidences of ischaemic events (to include peripheral ischaemia, cerebral infarction, and myocardial infarction) within 30 days of surgery (RR 0.67, 95% CI 0.25 to 1.77; 616 participants; absolute effect of 17 fewer participants per 1000 with an ischaemic event in the continuation group, ranging from 39 fewer to 40 more; four studies; low-certainty evidence).We used the GRADE approach to downgrade evidence for all outcomes owing to limited evidence from few studies. We noted a wide confidence in effect estimates for mortality at the end of follow-up and at 30 days, and for blood loss requiring transfusion which suggested imprecision. We noted visual differences in study results for ischaemic events which suggested inconsistency.

AUTHORS' CONCLUSIONS

We found low-certainty evidence that either continuation or discontinuation of antiplatelet therapy before non-cardiac surgery may make little or no difference to mortality, bleeding requiring surgical intervention, or ischaemic events. We found moderate-certainty evidence that either continuation or discontinuation of antiplatelet therapy before non-cardiac surgery probably makes little or no difference to bleeding requiring transfusion. Evidence was limited to few studies with few participants, and with few events. The three ongoing studies may alter the conclusions of the review once published and assessed.

Statin use is not associated with improved 30-day survival in patients undergoing surgery for colorectal cancer

PURPOSE

Besides the lipid-lowering properties, statins are thought to have anti-inflammatory effects and it has been shown that statins directly attenuate the inflammatory stress response after surgical trauma. The aim of the study was to examine the association between preoperative statin use and 30-day mortality as well as postoperative complications after curative-intended surgery for colorectal cancer.

METHODS

The study was a Danish nationwide register-based observational study. A total of 29,352 patients undergoing surgery for colorectal cancer between January 1, 2003, and December 31, 2012, were included in the study. At the time of surgery, 5961 were registered as statin users. The outcomes were 30-day mortality and risk of postoperative complications.

RESULTS

The adjusted hazard ratio of 30-day mortality was 0.91 (95 CI 0.80-1.04, P = 0.16) among statin users compared with the non-statin group. There was no difference between the two groups regarding the risk of infectious complications (sepsis, anastomotic leakage, pneumonia) (odds ratio 0.95, 95% CI 0.86-1.05, P = 0.31). For other postoperative complications (cardiovascular events, stroke, renal failure, respiratory insufficiency, and thromboembolic events), there was no significant difference between the two groups (odds ratio 0.89, 95% CI 0.78-1.01, P = 0.06).

CONCLUSION

The study did not show an improved 30-day survival after surgery for colorectal cancer in patients treated with statins in the year preceding surgery. No overall association with the risk of postoperative complications was shown.

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.

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.

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.

Effects of preoperative statin use on perioperative outcomes of carotid endarterectomy

OBJECTIVES

Several studies have shown the beneficial role of statins in reducing the risk of major perioperative complications and death associated with noncardiac vascular surgery, but few have focused on their effects in the event of carotid endarterectomy (CEA). This study analyzes the effects of preoperative statin use on perioperative outcomes in patients undergoing CEA.

MATERIALS AND METHODS

Data from all consecutive patients who underwent primary CEA for symptomatic and asymptomatic carotid disease between 2002 and 2014 at a single institution were prospectively stored in a vascular surgery registry, recording risk factors, medication, and indication for surgery. Endpoints of the study were perioperative (30-day) stroke and death.

RESULTS

Overall, 784 patients were on statins (825 CEAs, Group I), while 494 were not (545 CEAs, Group II). There were two perioperative strokes in Group I (0.24%) and four in Group II (0.73%; p = .22), and no deaths. The only nonfatal cardiac complication occurred in Group II (0.18%, p = .39). A neurologist assessed patients at 1, 6, and 12 months after CEA, and every 2 years thereafter. Follow-up (range: 0.1-13 years; mean, 6.3 ± 3.7 years) was obtained for 1,239 patients (1,326 CEAs). Because 165 patients (166 CEAs) crossed over from Group II to Group I during the follow-up time, long-term data were stratified by postoperative statin treatment rather than by preoperative statin use. The 5- and 10-year restenosis/occlusion and survival rates did not differ significantly between the two groups.

CONCLUSIONS

Taking statins prior to CEA did not seem to affect the risk of major perioperative ischemic events and death, most likely due to the extremely low overall incidence of perioperative complications.

Postoperative management

Most patients undergoing major aortic surgery have multiple comorbidities and are at high risk of postoperative complications that affect multiple organ systems. Different aortic pathologies and surgical repair techniques have specific impact on the postoperative course. Ischemia-reperfusion injury is the common denominator in aortic surgery and influences the integrity of end-organ function. Common postoperative problems include hemodynamic instability due to the immediate inflammatory response, renal impairment, spinal cord ischemia, respiratory failure with prolonged mechanical ventilation, and gastrointestinal symptoms such as ileus or mesenteric ischemia. Focused care bundles to establish homeostasis and a team working toward an early functional recovery determine the success of effective rehabilitation and outcomes after aortic surgery.

Efficacy of atorvastatin in prevention of atrial fibrillation after heart valve surgery in the PROFACE trial (PROphylaxis of postoperative atrial Fibrillation After Cardiac surgEry)

Background

To evaluate the efficacy of perioperative atorvastatin administration for prophylaxis of postoperative atrial fibrillation (POAF) after heart valve surgery.

Methods

Our study included 90 patients with heart valve disease who were scheduled to undergo elective cardiac surgery. Cases with previous AF or preoperative beta-blocker therapy were excluded. Patients were randomized into the atorvastatin group, which included 47 patients who received 40 mg/day of atorvastatin 7 days before and after the surgery and the control group, which included 43 patients. Primary endpoint was the occurrence of POAF. Secondary endpoints included modifications in the preoperative and postoperative levels of the markers of inflammation (C-reactive protein [CRP]), myocardial injury (ultrasensitive troponin T and creatinine phosphokinase MB [CPK-MB]), and cardiac dysfunction (pro-brain natriuretic peptide [proBNP]) related to POAF and changes in the echocardiographic parameters, such as atrial electromechanical interval, A wave, E/A ratio, and Doppler imaging systolic velocity wave amplitude, related to POAF.

Results

No relationship between atorvastatin administration and reduction in the incidence of POAF was observed (42.6% in the atorvastatin vs. 30.2% in the control group) (p=0.226). No difference in the levels of CPK-MB, ultrasensitive troponin T, CRP, or proBNP and in the analyzed echocardiographic parameter was detected between both groups.

Conclusions

Atorvastatin in the described dose, was not adequate for the prophylaxis of POAF after heart valve surgery. It was ineffective in controlling the inflammatory phenomena, myocardial injury, and echocardiographic predictors of POAF.

Hypoxia-induced inflammation and purinergic signaling in cross clamping the human aorta

Open aortic surgery evokes a systemic inflammatory response and is associated with high morbidity and mortality. Purinergic signaling has been shown to be crucial for maintaining vascular integrity and attenuating inflammation related to hypoxia. The involvement of purinergic signaling in cross clamping of major human arteries is unknown. Our aim was to compare systemic inflammatory responses and hypoxia-induced purinergic signaling in patients undergoing either open infra-renal abdominal aortic repair or infra-inguinal revascularization. Pre- and 24 h post-operative blood samples were gathered from 6 patients undergoing aortic clamping and 6 similar patients undergoing common femoral artery cross-clamping. Using Biorad Multipex™ 21- and 27-panels 48 different cytokines, chemokines and growth factors were analyzed, in addition to circulating levels of ATP, ADP, CD39, CD73 and HIF-1α, and compared between the groups. Several inflammatory cytokines were elevated from baseline levels after aortic clamping, but not after femoral cross clamping. Most pronoun rises were seen in IL-6 (667 %, P = 0.016) and HGF (760 %, P = 0.016). HIF-1α values showed a steady increase after clamping of either artery unless the subject underwent blood transfusion. Despite an adequate increase in HIF-1α CD39 and CD73 activity decreased significantly after aortic clamping (P = 0.047 and P = 0.016, respectively). Aortic clamping is associated with a clear and strong systemic inflammatory response and impaired repair mechanisms in terms of purinergic signaling. Patients undergoing open aorta repair could benefit from pre-operative medical therapy, which enhances CD73 expression.

[Cardiovascular assessment and management prior to non-cardiac surgery. Comment on the new 2014 ESC/ESA guidelines]

In 2014 the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA) published an update of the guidelines on "non-cardiac surgery: cardiovascular assessment and management". Epidemiological data underline the relevance of these guidelines: a total of 5.7 million surgical procedures are performed per year in patients with increased cardiac risk and approximately 167,000 cardiac complications occur per year in Europe of which 19,000 are life-threatening. This new version of the guidelines highlights the patient characteristics, such as functional capacity and comorbidities and procedure-specific aspects for perioperative risk stratification. Decision-making for preoperative stress tests and coronary angiography has been simplified, procedure-specific risks have been revised and the role of multidisciplinary teamwork for high risk procedures is emphasized. A standardized stepwise approach on how to stratify patient-specific and procedure-associated risks has been established. For the first time, the guidelines recommend perioperative regimens on dual antiplatelet therapy and the new oral anticoagulants (NOAC).

Initiation patterns of statin therapy among adult patients undergoing intermediate to high-risk non-cardiac surgery

BACKGROUND

A growing body of literature has been produced on the potential role of statins in reducing perioperative cardiac events in patients undergoing non-cardiac surgery. However, evidence remains inconsistent, and little is known about the patterns of perioperative statin use in routine care.

OBJECTIVES

The objective of this study was to examine patterns of perioperative statin initiation among adults undergoing non-cardiac elective surgery in the USA.

METHODS

Using data from a large US healthcare insurer, we identified patients aged ≥18 years who underwent moderate-risk to high-risk non-cardiac elective surgery between 2003 and 2012 and initiated statins within 30 days before surgery. We evaluated temporal trends of statin initiation and patient characteristics. In a matched analysis, we assessed the effect of temporal proximity to surgery on the likelihood of statin initiation.

RESULTS

Of 460,154 patients undergoing surgery, 5628 (12 per 1000 patients) initiated a statin within 30 days before surgery. Statin initiation increased from 8 per 1000 patients in 2003 to 15 in 2012 (p = 0.0022). The increase was more pronounced among patients undergoing vascular surgery (149 initiators per 1000 patients by the end of 2012) and with Revised Cardiac Risk Index (RCRI) score ≥2 (72 per 1000 patients). Proximity to surgery, in particular vascular surgery, was predictive of statin initiation.

CONCLUSIONS

Despite the lack of robust evidence, perioperative statin initiation progressively increased from 2003 to 2012, particularly among patients undergoing major vascular surgery and with higher RCRI score. These trends were largely attributable to the initiation of statins in anticipation of non-cardiac surgery rather than routine dyslipidemia treatment.

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.

Addressing the Global Burden of Trauma in Major Surgery

Despite a technically perfect procedure, surgical stress can determine the success or failure of an operation. Surgical trauma is often referred to as the "neglected step-child" of global health in terms of patient numbers, mortality, morbidity, and costs. A staggering 234 million major surgeries are performed every year, and depending upon country and institution, up to 4% of patients will die before leaving hospital, up to 15% will have serious post-operative morbidity, and 5-15% will be readmitted within 30 days. These percentages equate to around 1000 deaths and 4000 major complications every hour, and it has been estimated that 50% may be preventable. New frontline drugs are urgently required to make major surgery safer for the patient and more predictable for the surgeon. We review the basic physiology of the stress response from neuroendocrine to genomic systems, and discuss the paucity of clinical data supporting the use of statins, beta-adrenergic blockers and calcium-channel blockers. Since cardiac-related complications are the most common, particularly in the elderly, a key strategy would be to improve ventricular-arterial coupling to safeguard the endothelium and maintain tissue oxygenation. Reduced O2 supply is associated with glycocalyx shedding, decreased endothelial barrier function, fluid leakage, inflammation, and coagulopathy. A healthy endothelium may prevent these "secondary hit" complications, including possibly immunosuppression. Thus, the four pillars of whole body resynchronization during surgical trauma, and targets for new therapies, are: (1) the CNS, (2) the heart, (3) arterial supply and venous return functions, and (4) the endothelium. This is termed the Central-Cardio-Vascular-Endothelium (CCVE) coupling hypothesis. Since similar sterile injury cascades exist in critical illness, accidental trauma, hemorrhage, cardiac arrest, infection and burns, new drugs that improve CCVE coupling may find wide utility in civilian and military medicine.

Association between pre-operative statin use and major cardiovascular complications among patients undergoing non-cardiac surgery: the VISION study

AIMS

The aim of this study was to assess the effects of pre-operative statin therapy on cardiovascular events in the first 30-days after non-cardiac surgery.

METHODS AND RESULTS

We conducted an international, prospective, cohort study of patients who were ≥45 years having in-patient non-cardiac surgery. We estimated the probability of receiving statins pre-operatively using a multivariable logistic model and conducted a propensity score analysis to correct for confounding. A total of 15 478 patients were recruited at 12 centres in eight countries from August 2007 to January 2011. The matched population consisted of 2845 patients (18.4%) treated with a statin and 4492 (29.0%) controls. The pre-operative use of statins was associated with lower risk of the primary outcome, a composite of all-cause mortality, myocardial injury after non-cardiac surgery (MINS), or stroke at 30 days [relative risk (RR), 0.83; 95% confidence interval (CI), 0.73-0.95; P = 0.007]. Statins were also associated with a significant lower risk of all-cause mortality (RR, 0.58; 95% CI, 0.40-0.83; P = 0.003), cardiovascular mortality (RR, 0.42; 95% CI, 0.23-0.76; P = 0.004), and MINS (RR, 0.86; 95% CI, 0.73-0.98; P = 0.02). There were no statistically significant differences in the risk of myocardial infarction or stroke.

CONCLUSION

Among patients undergoing non-cardiac surgery, pre-operative statin therapy was independently associated with a lower risk of cardiovascular outcomes at 30 days. These results require confirmation in a large randomized trial.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov NCT00512109.

Effect of statins on early and late clinical outcomes of carotid endarterectomy and the rate of post-carotid endarterectomy restenosis

BACKGROUND

This study analyzed the effect of statins on clinical outcomes after carotid endarterectomy (CEA) and the rate of restenosis.

STUDY DESIGN

We performed a retrospective analysis of prospectively collected data on 500 consecutive CEAs followed at 1, 6, and 12 months and every year.

RESULTS

There were 299 patients on statins vs 201 without. Combined perioperative MI/death rates were 2.7% vs 4% (p = 0.416) and MI/stroke/death rates were 4% vs 5% (p = 0.607) for statins vs no statins. At mean follow-up (27 months), MI, stroke, and death rates were: 9.7%, 2.3%, and 2.3% vs 9%, 2.5% and 4.5% (p = 0.18) for statins vs no statins, respectively. Diabetic patients not on statins had 4 times more deaths (8.5% vs 2.3%) and twice as many strokes/deaths (10.2% vs 5.3%). Patients with hypercholesterolemia who were not on statins had twice as many deaths (4.3% vs 2.2%). Rates of freedom from stroke/MI/death at 1, 2, 3, and 4 years were: 94%, 90%, 85% and 77% vs 94%, 89%, 85%, and 82% (p = 0.87) for statins vs no statins, respectively. Rates of freedom from death only for patients on statins vs no statins at 1, 2, 3, and 4 years were: 98%, 98%, 97.4% and 97.4% vs 98%, 96%, 94.8% and 94.8%, respectively (p = 0.191). For diabetic patients, rates of freedom from death at 1, 2, 3, and 4 years were 99%, 99%, 97%, and 97% for statins vs 97%, 90%, 90%, and 90% without statins, respectively (p = 0.048). Post-CEA restenosis rates ≥ 50% were not significantly different between statins vs no statins (p = 0.64).

CONCLUSIONS

Statins significantly lowered death rates in patients with diabetes and tended to lower both death and stroke rates in diabetic patients and patients with hypercholesterolemia. Statins had no effect on post-CEA restenosis.

Effects of atorvastatin on plasma matrix metalloproteinase-9 concentration after glial tumor resection; a randomized, double blind, placebo controlled trial

Background

Neurosurgical procedures such as craniotomy and brain tumor resection could potentially lead to unavoidable cerebral injuries. Matrix metalloproteinase-9 (MMP-9) is up-regulated in neurological injuries. Statins have been suggested to reduce MMP- 9 level and lead to neuroprotection. Atorvastatin preoperatively administered to evaluate its neuroprotective effects and outcome assessment in neurosurgical-induced brain injuries after glial tumor resection. In this prospective, randomized, double-blind, placebo-controlled trial, 42 patients undergoing glial tumor surgery randomly received 40 mg atorvastatin or placebo twice daily from seven days prior to operation and continued for a 3 weeks period. Plasma MMP-9 concentration measured 4 times, immediately before starting atorvastatin or placebo, immediately before surgery, 24 hours and two weeks after the surgery. Karnofsky performance score was assessed before first dose of atorvastatin as a baseline and 2 months after the surgery.

Results

Karnofsky performance scale after surgery raised significantly more in Atorvastatin group (11.43 +/- 10.62 vs. 4.00 +/- 8.21) (p = 0.03). Atorvastatin did not significantly reduce MMP-9 plasma concentration 24 hours after surgery in comparison to placebo. No statistical significance detected regarding length of hospital stay among the groups. Significant reduction in MMP-9 plasma concentration was recorded in atorvastatin group two weeks after surgery (p = 0.048).

Conclusions

Significant statistical differences detected with atorvastatin group regarding MMP-9 plasma concentration, clinical outcome and Karnofsky performance score. Consequently, atorvastatin use may lead to better outcome after neurosurgical procedures.