A peri-operative statin update for non-cardiac surgery. Part I: The effects of statin therapy on atherosclerotic disease and lessons learnt from statin therapy in medical (non-surgical) patients

Pleiotropic vascular protective effects of statins in perioperative medicine

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor (statins) is one of the most commonly prescribed agents for controlling hyperlipidemia. Apart from their lipid-lowering property, statins are well known for their pleiotropic effects, such as improvement of vascular endothelial dysfunction, attenuation of inflammatory responses, stabilization of atherosclerotic plaques, inhibition of vascular smooth muscle proliferation, and modulation of procoagulant activity and platelet function. The vasculo-protective effect of statins is mainly mediated by inhibition of the mevalonate pathway and oxidized low-density lipoprotein generation, thereby enhancing the biosynthesis of endothelium-derived nitric oxide. Accumulating clinical evidence strongly suggests that administration of statins reduces overall mortality, the development myocardial infarction and atrial fibrillation, and length of hospital stay after a major cardiac/noncardiac surgery. This review updates the clinical pharmacology and therapeutic applications of statins during major operations, and highlights the anesthesia considerations for perioperative statin therapy.

Effects of adding statins before surgery on mortality and major morbidity: a meta-analysis

OBJECTIVE

To re-evaluate the effects of adding a statin before surgery on mortality at 30 days and at 1 year and on major morbidity at 0-30 days.

DESIGN

A meta-analysis of parallel, randomized, controlled trials published in English.

SETTING

A university-based electronic search.

PARTICIPANTS

Adult patients undergoing any type of procedure.

INTERVENTION

Adding a statin before a procedure compared to a placebo or no intervention.

MEASUREMENTS AND MAIN RESULTS

A search for all randomized controlled trials (RCT) was done in PubMed, Embase, Ovid MEDLINE and the Cochrane Central Register of Controlled Trials in November 2012. The quality of each study was assessed with the Cochrane Collaboration Tools. An I-square ≥ 25% was chosen as the cut-off point for heterogeneity exploration. The search produced 29 trials. Statins reduced the 0-30 days' risk of myocardial infarction: risk ratio (RR) 0.48 (95%CI 0.38, 0.61); I-square 13.2%; p<0.001; number needed-to-treat 17 (14, 24). There were no statistical differences at 0-30 days for stroke RR 0.70 (0.25, 1.95), acute renal insufficiency RR 0.54 (0.26, 1.12) or reoperation RR 1.10 (0.51, 2.38). There was a trend for a reduced mortality at 1 year RR 0.26 (0.06, 1.02); I-square 0%; p = 0.053. The hospital length of stay was slightly decreased with atorvastatin: standardized mean difference (SMD) -0.27 (-0.39, -0.14), p<0.001; fluvastatin SMD -0.95 (-1.56, -0.34), p = 0.002; and rosuvastatin SMD -0.69 (-0.98, -0.40), p<0.001 but not with simvastatin SMD -0.04 (-0.41, 0.48).

CONCLUSIONS

Adding a statin before a high risk cardiac procedure reduces the 0-30 days' risk of myocardial infarction.

Perioperative statin use: an update

HMG CoA reductase inhibitors (statins) are a proven modality to reduce serum cholesterol and have been shown to reduce morbidity and mortality in cardiovascular patients. Statins have also demonstrated improvements in postoperative outcomes among patients taking them in the perioperative period. Many of the studies are limited to select patient populations and/or select surgeries. This review will give an overview of the pharmacology of statins, summarize the mechanisms of the beneficial effects of statins, and provide an overview of evidence in the use of statins in the perioperative period.

Drugs mediating myocardial protection

The occurrence of myocardial ischaemia will result in either reversible or irreversible myocardial dysfunction. Even when revascularization is successful, some reperfusion injury may occur that transiently impairs myocardial function. Therefore, treatment should not only be directed towards prompt restoration of myocardial blood flow but measures should also be taken to prevent or alleviate the consequences of myocardial reperfusion injury. Over the years, various strategies have been developed. The present contribution reviews a number of these strategies focusing on pharmacological treatments that have been developed to address myocardial reperfusion injury.

Cardiovascular problems in noncardiac surgery

PURPOSE OF REVIEW

Perioperative cardiac complications remain a major area of concern as our surgical population increases in volume, age and frequency of comorbidity. A variety of strategies can be used to optimize patients and potentially reduce the incidence of these serious complications.

RECENT FINDINGS

Recent literature suggests a trend towards less invasive testing for detection and quantification of coronary artery disease and greater interest in pharmacologic 'cardioprotection' using beta-blockers, statins and other agents targeting heart rate control and other mechanisms (e.g. reducing inflammatory responses). The recent Perioperative Ischemic Evaluation study has substantially altered this approach at least towards widespread application to lower/intermediate risk cohorts. Considerable attention has been focused on ensuring optimal standardized perioperative management of patients with a recent percutaneous coronary intervention, particularly those with an intracoronary stent. Widespread surveillance of postoperative troponin release and increasing recognition of the prognostic potential of elevated preoperative brain natriuretic peptides point towards changing strategies for long-term risk stratification.

SUMMARY

The complexity of a particular patient's physiologic responses to a wide variety of surgical procedures, which are undergoing constant technological refinement generally associated with lesser degrees of invasivity and stress make calculation of patients' perioperative risk very challenging. At the present time, adequate information is available for the clinician to screen patients with high-risk preoperative predictors, delay elective surgery for patients with recent intracoronary stents and continue chronic beta-blockade in appropriate patients. New large-scale database and subanalyses of major trials (e.g. Perioperative Ischemic Evaluation and Coronary Artery Revascularization Prophylaxis) should provide additional information to minimize perioperative cardiac risk.

[Minimizing perioperative risk - an interdisciplinary effort]

Physicians involved in perioperative care have to face new challenges because of the continuing aging of the population and medical progress, which facilitates even more invasive surgery. The risk of surgical procedures is elevated in patients with cardiac co-morbidity necessitating an optimization of both clinical condition and preoperative therapy of these patients. Innovative therapeutic concepts like fast-track surgery, new approaches in coronary revascularisation, and new strategies of anticoagulation require an interdisciplinary treatment of these patients and a strict collaboration of surgeons and anaesthesiologists with the colleagues from other nonsurgical disciplines like internal medicine and cardiology. Physicians should start beforehand the interdisciplinary preparation of surgical patients as out-patients and should continue this approach during the stay in hospital. In this review, we describe the major perioperative cardiac, pulmonary and vascular risks for physicians involved in the treatment of surgical patients.

A peri-operative statin update for non-cardiac surgery. Part II: Statin therapy for vascular surgery and peri-operative statin trial design

This is the second of two review articles evaluating peri-operative statin therapy. In surgical patients, the utility of peri-operative statin therapy is strongly suggested by retrospective studies, although it is probably overestimated, as important confounding factors have not been controlled for and hence the literature is considered to be currently inconclusive. This review examines the potential mechanisms and indications for peri-operative statin protection, the efficacy of acute peri-operative beta-blockade in addition to statin therapy, the effect of peri-operative statin therapy withdrawal and the implications of comorbidities associated with peri-operative cardiovascular risk on statin therapy. Recommendations concerning appropriate dosing, duration, therapeutic targets and necessary investigations when prescribing peri-operative statins are made. Peri-operative study design recommendations are suggested, so that future meta-analyses may be more informative. Recommendations are made regarding retrospective reporting of statin studies to minimise the bias inherent in a number of the current retrospective studies on this subject.