Impact of Chronic Statin Use During Surgery on Inflammation and Infection Rates
Information source: Ottawa Hospital Research Institute
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Inflammation; Infection; Endothelial Function
Intervention: Atorvastatin (Drug); Atorvastatin (Drug); Atorvastatin (Drug); Atorvastatin (Drug); Control (Other)
Phase: N/A
Status: Completed
Sponsored by: Ottawa Hospital Research Institute Official(s) and/or principal investigator(s): David T Neilipovitz, MD, Principal Investigator, Affiliation: The Ottawa Hospital Greg L Bryson, MD, Principal Investigator, Affiliation: The Ottawa Hospital
Summary
Despite improvements in perioperative care, non-cardiac surgery remains associated with
significant and costly complications. Analysis of perioperative deaths in the United Kingdom
suggests that roughly 80% are directly attributable to infectious and cardiovascular
complications. The best available evidence suggests that medical optimization is the
preferred strategy to reduce cardiac risks but there has been no novel strategy to reduce
nosocomial infection rates in over 20 years.
Emerging evidence in both the non-operative and operative setting suggest that statin drugs
may prevent both infectious and cardiac events. The mechanism(s) of action are not entirely
clear but appear to independent of lipid lowering effects and are often referred to as
pleiotropic effects. Two key elements of the pleiotropic effects of statins appear to be
their anti-inflammatory properties and improved endothelial vascular reactivity. The statin
dose required to maximize these effects is unknown. A large observational trial suggests a
contradictory dose effect with higher doses associated with reduced infectious complications
and lower doses associated with fewer cardiac complications. Doctors therefore still have
many unanswered questions about the use of statins in the perioperative setting. Should they
be routinely started on all or only certain surgical patients? What dose of statin should be
used? If a patient is already on a statin, should their dose be altered perioperatively? The
latter question is particularly relevant in light of the marked increase in statin use.
Recruitment logs for an ongoing trial demonstrate that over 70% of patients undergoing
high-risk surgery were taking a statin but at markedly variable doses. This population
presents an ideal opportunity to determine if there is a dose response relationship between
statins and pleiotropic effects. We therefore propose an observational study that will
determine anti-inflammatory and endothelial effects in high-risk surgical patients on
varying doses of a perioperative statin drug.
Atorvastatin diminishes the rise in C-reactive protein (CRP), measured 48 hours after
elective vascular surgery, in a dose dependent fashion.
Secondary Hypotheses:
Atorvastatin reduces endothelial dysfunction after elective vascular surgery, as measured by
brachial artery ultrasound, in a dose dependent fashion.
Clinical Details
Official title: An Observational Trial of Perioperative Atorvastatin on Inflammatory and Endothelial Function in Patients Undergoing Vascular Surgery (STAR-VaS 2)
Study design: Observational Model: Case-Only, Time Perspective: Prospective
Primary outcome: C-reactive protein levels
Secondary outcome: brachial artery reactivity (assessed by ultrasound)Infection
Detailed description:
It is estimated that approximately 1. 7 million surgical procedures are performed each year
in Canada. Unfortunately, perioperative complications are not an uncommon occurrence and
have substantial morbidity, mortality and costs associated with them. To date, the best
strategies to reduce nosocomial infections are aseptic practices, timely prophylactic
antibiotics and good surgical technique. Despite these strategies, it is estimated that at
least 1 in 5 major vascular surgical patients will have some type of nosocomial infection
within 30 days of their procedure. The direct and indirect mortality of infections in this
population is difficult to estimate but nosocomial infections are estimated to contribute to
at least 15% of the mortality in hospitalized patients.
The primary manner in which infections contribute to patient mortality is by progression to
sepsis. Sepsis is the tenth leading cause of death in Canadians and worldwide is increasing
in incidence and severity. The associated mortality of sepsis varies by population and
infection source but is usually between 30-60%. Despite significant improvements in the
management of sepsis in the last 5 years, there is still no generally effective preventive
medication or strategy. Although cardiovascular complications, including myocardial
infarction and heart failure, are less common at 15% of major vascular patients, they have a
staggering mortality of around 30-50%. Clearly, strategies or therapies to reduce these
complications could have profound benefits. The questions are therefore whether statin drugs
reduce sepsis, cardiovascular complications, or both and, if they do, how might they do so.
Understanding of the pathophysiology of sepsis and acute coronary syndromes in the
non-operative setting has led to tremendous advancements in the management. In sepsis, an
excessive, inappropriate and misguided response in the host defense response is likely
responsible. Massive cytokine release exacerbates endothelium dysfunction that then impacts
coagulation, thrombolysis, inflammation, tissue repair and tissue growth. If not corrected,
the endothelial cells either die directly or through the triggering of apoptosis. This then
leads to multiorgan dysfunction and ultimately death. How sepsis ultimately impairs and
damages endothelial cell function is likely multifactoral. Impairment of endothelial nitric
oxide synthetase occurs that causes impaired perfusion and inappropriate microvasculature
coagulation.
In a strikingly similar manner to sepsis, key elements to acute coronary syndromes again
appear to be inflammation and endothelial dysfunction. Rupture of coronary plaques and
thrombosis are central. Although perioperative myocardial events are traditionally said to
be supply-demand problems, this theory is in dispute and evidence suggests that
perioperative problems are very similar to non-operative events. Elevated levels of various
inflammatory markers, particularly C-Reactive Protein, are associated with adverse
cardiovascular events. Similarly, the vascular endothelium is responsible for regulating
vasomotor tone, thrombosis, platelet and leukocyte interactions. Dysfunction of the
endothelium is also believed to be a central component of the development of coronary
complications. Although endothelial dysfunction has not been extensively investigated in the
perioperative setting, pathophysiologic similarities make it probable that perioperative
endothelial dysfunction contributes to the occurrence of perioperative myocardial events.
Thus, strategies designed to control perioperative inflammation, as well as to improve
endothelial function and stabilize coronary plaque have the potential to reduce both
perioperative coronary and infectious events.
Although studies in both animals and humans strongly suggest that statins may both prevent
and treat sepsis, no prospective randomized trials in humans have been conducted to
demonstrate these effects. Although some statins have been demonstrated to directly
attenuate replication and infectivity of microorganisms, the evidence primarily suggests
that if statins are indeed protective it will likely be due to their anti-inflammatory and
favorable endothelial effects. Improvement of endothelial function by statins has been
suggested to prevent cardiac events by stabilizing coronary plaques and may even contribute
to plaque regression. Statins restore endothelial production of endogenous nitric oxide
synthetase thus improving organ perfusion and microvasculature thrombosis that is impaired
in the setting of sepsis.
The goals of the proposed trial, STAR VaS II are therefore twofold: First, it will help
determine if statin blunts the adverse perioperative changes in inflammation and endothelial
function in a dose-dependent fashion. Second, it will determine if patients chronically on
lower than maximal statin dose should have their dose increased in the perioperative period.
We will evaluate the influence of varying doses of statins on perioperative inflammation,
as assessed by C-reactive protein, and endothelial function as assessed by brachial artery
ultrasound. If atorvastatin, chronically administered before surgery, improves inflammatory
changes or endothelial function in a dose dependent fashion, then it is plausible that
patients chronically on lower statin doses should have their dose increased in the
perioperative period. If however patients on lower doses experienced similar benefit, as
those on higher doses, then conceivably the recommended perioperative dose could be lower
thereby theoretically further improving the risk-benefit ratio for a statin drug. All
patients will be assessed for infections as defined by the CDC.
Eligibility
Minimum age: 45 Years.
Maximum age: N/A.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- over 45 years of age
- able to have a baseline brachial ultrasound test before their day of surgery
- elective high-risk surgery defined by use of the POISE criteria
Exclusion Criteria:
- lack of informed consent
- pregnant
- contraindication to the brachial artery ultrasound test protocol (i. e.
contraindication to 0. 4 mg sublingual nitroglycerin)
- enrolled in another conflicting study
- previously enrolled in STAR-VaS or STAR-VaS2
Locations and Contacts
The Ottawa Hospital, Ottawa, Ontario K1Y4E9, Canada
Additional Information
Starting date: November 2008
Last updated: July 19, 2011
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