Current uncertainty over the best approach for preventing fatal perioperative myocardial infarction (MI) lies in our inability, despite sophisticated testing methods, to detect unstable coronary plaque prior to surgery. Unstable plaque can be present in patients with coronary lumina that appear normal on coronary angiography. Therefore, reliance on medical therapy to blunt inflammation is currently the best practice for minimizing the risk that unstable plaque poses.
Perioperative use of statins is a cornerstone of such therapy. This article briefly reviews the rationale for perioperative statin use in the setting of noncardiac surgery, presents the latest evidence on the clinical effects of perioperative statin use, and considers the potential role for statins in promoting recovery from acute kidney injury after vascular surgery.
FATAL MI: ORIGINS AND APPROACHES TO RISK REDUCTION
Fatal perioperative MI has two potential origins. 1,2 One is a culprit coronary plaque that fissures and ruptures, causing a cascade of thrombogenic events (hemorrhage and thrombosis) inside the vessel wall, culminating in an MI. Less often, fatal perioperative MI results from long-lasting myocardial ischemia (a demand/supply mismatch of oxygen), typically as a consequence of a fixed coronary stenosis.
In nearly half of patients with fatal MI, coronary inflammation is a key contributor. In the perioperative setting, surgical stress induces the release of inflammatory cytokines that disrupt smooth muscle cells in the endothelium and contribute to disruption of a nonobstructing coronary plaque, predisposing to acute thrombus formation.
Risk reduction depends on pathophysiology
Strategies for minimizing the risk of perioperative MI depend on the pathophysiology involved. In the case of oxygen demand/supply mismatch as a result of flow-limiting stenosis, a beta-blocker and coronary revascularization, if possible, may be useful.
In the more common case of unstable plaque, a multifactorial strategy appears optimal, involving the following:
- Statin therapy to reduce coronary inflammation
- Aspirin to blunt the prothrombotic milieu postoperatively
- Chronic low-dose beta-blockade to decrease myocardial oxygen demand or inhibit plaque rupture.
A particular role for statins
Ridker et al found that patients with an acute coronary syndrome who experience a decline in high-sensitivity C-reactive protein (hsCRP) level after treatment with a statin have improved clinical outcomes compared with those whose hsCRP level remains high, regardless of their resultant low-density lipoprotein (LDL) cholesterol level. 3
Among surgical patients, those most at risk for poor cardiovascular outcomes are those who undergo vascular surgery. In Europe, the cardiovascular death rate in such patients is approximately 2%. 4
Retrospective cohort data and data from randomized clinical trials have demonstrated reductions in perioperative cardiac complications with statin use in patients undergoing various types of noncardiac vascular surgery. 5–9 In light of these data, my colleagues and I recently undertook a prospective study to examine the effect of perioperative statin use on cardiovascular complications in patients undergoing vascular surgery. 10 Key details and findings are surveyed in the following section.
DECREASE III: PROSPECTIVE EVIDENCE FOR ISCHEMIC BENEFIT FROM PERIOPERATIVE STATINS
The Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echo III (DECREASE III) was conducted at a single center (Erasmus Medical Center, Rotterdam, the Netherlands) in a randomized, double-blind, placebo-controlled manner. 10