Cardiac surgery can effectively treat patients with heart disease but is associated with a risk ratio for adverse events at the same time. Despite the increasing proportion of patients undergoing cardiac surgery with major co-morbidities, operative results have remained stable during past decades, which may be related to advancements in surgical techniques. Nonetheless, perioperative care of these patients remains to be optimised.
Statins (HMG-CoA reductase inhibitors) are prescribed to lower blood cholesterol levels but are known to provide beneficial effects beyond their lipid-lowering properties. In the past, studies have shown that statins are linked to lower mortality in patients with atherosclerotic cardiovascular disease. However, evidence for the beneficial effects of statins in patients undergoing cardiac surgery is inconsistent, as it is mainly extracted from observational studies and only a few small randomised clinical trials.
The aim of this review is to gather current evidence for preoperative statin therapy for reducing major adverse cardiovascular events in patients referred for cardiac surgical procedures. The first review was published in 2012, and the present review is an updated version.
We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and the metaRegister of Controlled Trials. We identified 17 studies dating from 1999 to 2014 with a total of 2138 participants undergoing cardiac surgical procedures. All included trials were randomised studies comparing statin treatment with a control intervention (no statin medication) or placebo in patients who were predominantly referred for coronary artery bypass grafting surgery.
Preoperative statin therapy resulted in a reduction in postoperative atrial fibrillation (AF) (12 studies) and a shorter stay both on the ICU (nine studies) and in the hospital (11 studies). Although statin pretreatment was associated with lower incidences of myocardial infarction (seven studies) and renal failure (five studies), these results did not reach statistical significance. Furthermore, statin therapy had no impact on short-term mortality (two studies) or postoperative stroke (two studies). No serious side effects of statin therapy given before cardiac surgery were reported. However, all analysed studies included mainly patients undergoing coronary bypass operations, thus results of these studies may not be generalisable to patients undergoing cardiac procedures other than coronary artery bypass grafting.
Preoperative statin therapy reduces the odds of postoperative atrial fibrillation (AF) and shortens the patient's stay on the ICU and in the hospital. Statin pretreatment had no influence on perioperative mortality, stroke, myocardial infarction or renal failure, but only two of all included studies assessed mortality. As analysed studies included mainly individuals undergoing myocardial revascularisation, results cannot be extrapolated to patients undergoing other cardiac procedures such as heart valve or aortic surgery.
Patients referred to cardiac surgery for cardiovascular disease are at significant risk for the development of major postoperative adverse events despite significant advances in surgical techniques and perioperative care. Statins (5-hydroxy-3-methylglutaryl-co-enzyme A (HMG-CoA) reductase inhibitors) have gained a pivotal role in the primary and secondary prevention of coronary artery disease and are thought to improve perioperative outcomes in patients undergoing cardiac surgery. This review is an updated version of a review that was first published in 2012.
To determine the effectiveness of preoperative statin therapy in patients undergoing cardiac surgery.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 11), MEDLINE (1950 to November 2013 Week 3), EMBASE (1980 to 3 December 2013 (Week 48)) and the metaRegister of Controlled Trials. Additionally, we searched ongoing trials through the National Research Register, the ClinicalTrials.gov registry and grey literature. We screened online conference indices from relevant scientific meetings (2006 to 2014) to look for eligible trials. We applied no language restrictions.
All randomised controlled trials comparing any statin treatment before cardiac surgery, for any given duration and dose, versus no preoperative statin therapy (standard of care) or placebo.
Two review authors evaluated trial quality and extracted data from titles and abstracts identified by electronic database searches according to predefined criteria. Accordingly, we retrieved full-text articles of potentially relevant studies that met the inclusion criteria to assess definitive eligibility for inclusion. We reported effect measures as odds ratios (ORs) or weighted mean differences (WMDs) with 95% confidence intervals (95% CIs).
We identified 17 randomised controlled studies including a total of 2138 participants undergoing on-pump or off-pump cardiac surgical procedures, and added to this review six studies with 1154 additional participants. Pooled analysis showed that statin treatment before surgery reduced the incidence of postoperative atrial fibrillation (AF) (OR 0.54, 95% CI 0.43 to 0.67; P value < 0.01; 12 studies, 1765 participants) but failed to influence short-term mortality (OR 1.80, 95% CI 0.38 to 8.54; P value = 0.46; two studies, 300 participants) or postoperative stroke (OR 0.70, 95% CI 0.14 to 3.63; P value = 0.67; two studies, 264 participants). In addition, statin therapy was associated with a shorter stay for patients on the intensive care unit (ICU) (WMD -3.19 hours, 95% CI -5.41 to -0.98; nine studies, 721 participants) and in the hospital (WMD -0.48 days, 95% CI -0.78 to -0.19; 11 studies, 1137 participants) when significant heterogeneity was observed. Results showed no reduction in myocardial infarction (OR 0.48, 95% CI 0.21 to 1.13; seven studies, 901 participants) or renal failure (OR 0.57, 95% CI 0.30 to 1.10; five studies, 467 participants) and were not affected by subgroup analysis. Trials investigating this safety endpoint reported no major or minor perioperative side effects of statins.