Statin therapy is associated with improved outcomes in vascular surgery patients with renal impairment

NAD+ Biosynthesis Impairment and Acute Kidney Injury after Major Vascular Surgery

Acute kidney injury (AKI) is a serious complication after vascular surgery. Reduced synthesis of nicotinamide adenine dinucleotide (NAD+) from tryptophan is associated with an increased risk of AKI in critically ill patients, patients hospitalized with COVID-19, and cardiac surgery patients, and is marked by elevated urinary quinolinate and quinolinate to tryptophan ratios. We measured quinolinate concentrations in vascular surgery patients to determine if impaired NAD+ synthesis was associated with AKI in this patient population. Eight preoperative and eight postoperative vascular surgery patients who developed AKI were selected from a parent study to participate in this single-center case-control study. They were matched with controls who did not develop AKI based on age, sex, BMI, eGFR, hypertension, and diabetes. Urinary quinolinate and tryptophan concentrations were measured at anesthetic induction and on postoperative day one. Two-sided Mann-Whitney U tests were used to compare quinolinate and quinolinate to tryptophan ratios. Multivariate linear regression modeling was used to estimate the relationship between quinolinate and serum creatinine. There was no difference in preoperative or postoperative urine quinolinate concentrations or the preoperative quinolinate to tryptophan ratio between patients that did and did not develop AKI (p = 0.07, 0.50, and 0.32, respectively). However, postoperative quinolinate to tryptophan ratios were higher in AKI patients (p = 0.04). Further, after adjustment for AKI risk factors, higher preoperative quinolinate concentrations and higher postoperative quinolinate to tryptophan ratios were associated with greater postoperative creatinine increases (p = 0.04 and 0.04, respectively). These data suggest that impaired NAD+ synthesis may contribute to AKI development in vascular surgery patients.

The role of osteoprotegerin in the development, progression and management of abdominal aortic aneurysms

Osteoprotegerin (OPG) appears to be a very promising marker both in the diagnosis of abdominal aortic aneurysms (AAAs) and as a potential target in its treatment. This article presents an overview of the current literature that discusses the role of OPG in the pathogenesis of atherosclerosis and its potential value as a prognostic factor in AAA. Pharmacological modulation of OPG expression has been considered. In conclusion, it seems that further research designed to assess the relationship between OPG and AAA is needed as this may contribute to improved AAA monitoring and more effective treatment of patients with AAA.

Comparison of outcomes after carotid endarterectomy between type 2 diabetic and non-diabetic patients with significant carotid stenosis

BACKGROUND

We aimed to compare early and late outcomes after carotid endarterectomy (CEA) between Korean type 2 diabetic and non-diabetic patients and to investigate the impact of diabetes on the overall incidence of cardiovascular events after CEA.

METHODS

We retrospectively analyzed 675 CEAs, which were performed on 613 patients with significant carotid stenosis between January 2007 and December 2014. The CEAs were divided into a type 2 diabetes mellitus (DM) group (n = 265, 39.3%) and a non-DM group (n = 410, 60.7%). The study outcomes included the incidence of major adverse events (MAEs), defined as fatal or nonfatal stroke or myocardial infarction or all-cause mortality, during the perioperative period and within 4 years after CEA.

RESULTS

Patients in the DM and non-DM groups did not differ significantly in the incidence of MAEs or any of the individual MAE manifestations during the perioperative period. However, within 4 years after CEA, the difference in the MAE incidence was significantly greater in the DM group (P = 0.040). Analysis of the individual MAE manifestations indicated a significantly higher risk of stroke in the DM group (P = 0.006). Multivariate analysis indicated that diabetes was not associated with MAEs or individual MAE manifestations during the perioperative period, whereas within 4 years after CEA, diabetes was an independent risk factor for MAEs overall (hazard ratio [HR], 1.62; 95% confidence interval [CI] 1.06-2.48; P = 0.026) and stroke (HR, 2.55; 95% CI 1.20-5.41; P = 0.015) in particular.

CONCLUSIONS

Diabetic patients were not at greater risk of perioperative MAEs after CEA; however, the risk of late MAE occurrence was significantly greater in these patients. Within 4 years after CEA, DM was an independent risk factor for the occurrence of MAEs overall and stroke in particular.

Current and emerging treatments for hypercholesterolemia: A focus on statins and proprotein convertase subtilisin/kexin Type 9 inhibitors for perioperative clinicians

Statins are a mainstay of hyperlipidemia treatment. These drugs inhibit the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase and have beneficial effects on atherosclerosis including plaque stabilization, reduction of platelet activation, and reduction of plaque proliferation and inflammation. Statins also have a benefit beyond atherosclerotic plaque, including anticoagulation, vasodilatation, antioxidant effects, and reduction of mediators of inflammation. In the perioperative period, statins appear to contribute to improved outcomes via these mechanisms. Both vascular and nonvascular surgery patients have been shown in prospective studies to have lower risk of adverse cardiac outcomes when initiated on statins preoperatively. However, not all patients can tolerate statins; the search for novel lipid-lowering therapies led to the discovery of the proprotein convertase subtilisin/kexin Type 9 (PCSK9) inhibitors. These drugs are fully-humanized, injectable monoclonal antibodies. With lower PCSK9 activity, low-density lipoprotein cholesterol (LDL-C) receptors are more likely to be recycled to the hepatocyte surface, where they serve to clear plasma LDL-C. Evidence from several prospective studies shows that these new agents can significantly lower LDL-C levels. While PCSK9 inhibitors offer hope of effective therapy for patients with familial hyperlipidemia or intolerance of statins, several important questions remain, including the results of long term cardiovascular outcome studies. The perioperative effects of new LDL-C-lowering drugs are unknown at present but are likely to be similar to the older agents.

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.

The effect of adding ezetimibe to rosuvastatin on renal function in patients undergoing elective vascular surgery

We compared the effects of lipid lowering with rosuvastatin (RSV) monotherapy versus intensified treatment by combining RSV with ezetimibe (EZT) on kidney function in patients undergoing vascular surgery. Patients were randomly assigned to either 10 mg/d RSV (n = 136) or RSV 10 mg/d plus EZT 10 mg/d (RSV/EZT, n = 126). At 12 months, a similar decrease in estimated glomerular filtration rate (eGFR) was noted. Patients who achieved a low-density lipoprotein cholesterol (LDL-C) of <100 mg/dL had less eGFR decrease than those patients having an LDL-C limit of more than 100 mg/dL. There were no significant changes in the urinary total protein to creatinine ratio in either group. Significant microalbuminuria was evident in both the groups. Patients undergoing vascular surgery show deterioration in their renal function during the first year, despite statin therapy. Intensified lipid-lowering therapy by adding EZT does not appear to have any renoprotective effect.

Preoperative estimates of glomerular filtration rate as predictors of outcome after surgery: a systematic review and meta-analysis

BACKGROUND

Kidney dysfunction is a strong determinant of prognosis in many settings.

METHODS

A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included.

RESULTS

Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 m l · min · 1.73 m(-2) was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95-4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22-4.41). An eGFR less than 60 ml · min · 1.73(-2) m was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38-1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32-1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml · min · 1.73m(-2) the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml · min · 1.73 m(-2) was 1.62 (95% CI 1.43-1.80), rising to 2.85 (95% CI 2.49-3.27) in patients with an eGFR less than 30 ml · min · 1.73 m(-2) and 3.75 (95% CI 3.44-4.08) in those with an eGFR less than 15 ml · min · 1.73 m(-2).

CONCLUSION

: There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.

Statins and noncardiac vascular disease

PURPOSE OF REVIEW

To discuss the beneficial effects of statin treatment in patients with peripheral arterial disease (PAD), abdominal aortic aneurysms (AAAs), atherosclerotic renal artery stenosis (ARAS) and carotid artery disease.

RECENT FINDINGS

Evidence suggests that statins may reduce the progression (or even reverse the development) of carotid artery stenosis and AAAs. Statins also improve several indices (e.g. serum creatinine) and preserve renal function in ARAS. In patients with PAD, statins are associated with improved claudication distance and time, reduced cardiovascular events, and improved graft patency rates should these patients undergo surgery. Finally, statins are associated with improved perioperative and long-term morbidity and mortality rates in all vascular patients whether they undergo surgery or endovascular procedures.

SUMMARY

Routine statin treatment should be implemented for all vascular patients to ensure a reduced progression of their disease, as well as a reduction in cardiovascular events.

Bias in observational studies of prevalent users: lessons for comparative effectiveness research from a meta-analysis of statins

Randomized clinical trials (RCTs) are usually the preferred strategy with which to generate evidence of comparative effectiveness, but conducting an RCT is not always feasible. Though observational studies and RCTs often provide comparable estimates, the questioning of observational analyses has recently intensified because of randomized-observational discrepancies regarding the effect of postmenopausal hormone replacement therapy on coronary heart disease. Reanalyses of observational data that excluded prevalent users of hormone replacement therapy led to attenuated discrepancies, which begs the question of whether exclusion of prevalent users should be generally recommended. In the current study, the authors evaluated the effect of excluding prevalent users of statins in a meta-analysis of observational studies of persons with cardiovascular disease. The pooled, multivariate-adjusted mortality hazard ratio for statin use was 0.77 (95% confidence interval (CI): 0.65, 0.91) in 4 studies that compared incident users with nonusers, 0.70 (95% CI: 0.64, 0.78) in 13 studies that compared a combination of prevalent and incident users with nonusers, and 0.54 (95% CI: 0.45, 0.66) in 13 studies that compared prevalent users with nonusers. The corresponding hazard ratio from 18 RCTs was 0.84 (95% CI: 0.77, 0.91). It appears that the greater the proportion of prevalent statin users in observational studies, the larger the discrepancy between observational and randomized estimates.

Progress in perioperative medicine: focus on statins

Beyond cholesterol reduction, statins have multiple beneficial influences on vascular endothelial function, atherosclerotic plaque stability, inflammation, and thrombosis. These favorable pleiotropic effects may be the basis for their perioperative risk reduction in cardiothoracic and vascular procedures. The published evidence suggests that statins offer significant outcome benefits throughout perioperative practice. Because statin therapy significantly reduces the perioperative risk for patients undergoing cardiovascular procedures, they already are recommended in published guidelines. Beyond cardiac risk reduction, statin therapy also may protect the brain and the kidney in the perioperative setting, both in cardiac and vascular surgery. The pleiotropic effects of statins also appear to have therapeutic roles in the progression of valve disease, sepsis, and venous thrombosis. Further trials are required to provide data to drive their safe and comprehensive perioperative application for optimal patient outcome both in the short term and the long term. Because there are multiple randomized trials currently in progress throughout perioperative medicine, it is very likely that the indications for statins will be expanded significantly.

Can Laboratory Tests Predict the Prognosis of Patients after Endovascular Aneurysm Repair? Current Status and Future Directions

The purpose of this study was to determine what laboratory values predict the prognosis of patients after endovascular aneurysm repair (EVAR). MEDLINE and Cochrane Library databases were searched. This resulted in 13 relevant articles. Data were pooled, and meta-analyses were performed. A meta-analysis including 5,655 patients showed that preoperative serum creatinine > 1.5 mg/dL was a significant risk indicator for increased 30-day mortality (relative risk 3.0, 95% confidence interval 2.3–4.1, p < .0001). Four other studies showed that other cutoff values of creatinine or glomerular filtration rate can predict mortality and complications following EVAR. One study suggested that reduced preoperative hemoglobin is a risk indicator for reduced long-term survival. Increased serum creatinine, reduced glomerular filtration rate, and reduced hemoglobin are significant and strong predictors of mortality and complications after EVAR. Current evidence remains limited, and further research is needed to determine conclusively additional laboratory values that may predict the outcome of patients following EVAR.

Effect of statin therapy on serum activity of proteinases and cytokines in patients with abdominal aortic aneurysm

Background and aims:

Metalloproteinases (MMPs) are considered to be key enzymes in the pathogenesis of abdominal aortic aneurysms (AAA), with elevated levels in diseased aorta and in patient sera. Statins seem to exert an inhibitory effect on MMP activity in the aortic wall. No data exist on the effect of statins on serum activity of MMPs and inflammatory cytokines (interleukins, IL).

Methods:

The serum activities of MMP2 and MMP9, osteoprotegerin (OPG), and IL6 and IL10 in 63 patients undergoing elective infrarenal aneurysm repair were measured on the day before surgery. Levels were correlated to statin therapy and aneurysm diameter.

Results:

There was no significant difference between the two groups in the activity of circulating levels of MMP2/9, OPG, and IL6/10 in patients with infrarenal aortic aneurysm. IL6 levels in patients with AAA larger than 6 cm were significantly elevated; differences in serum activities of MMP2/9, OPG, and IL10 were not related to AAA diameter.

Conclusion:

Serum activities of MMP2/9, OPG, and IL6/10 are not correlated to statin therapy; IL6 levels are higher in patients with large aneurysms. Hence the effect of statin therapy in the treatment of aneurismal disease remains to be elucidated.

Lipid abnormalities and cardiovascular risk in the elderly

The relationship between dyslipidaemia and cardiovascular disease is well documented. However, it is relevant to consider that cholesterol levels vary with age. Moreover, there is some controversy regarding the ability of lipid levels to predict vascular risk beyond the age of 70 years. In general, raised low-density lipoprotein cholesterol (LDL-C) and triglyceride levels as well as reduced levels of high-density lipoprotein cholesterol (HDL-C) predict risk in the elderly. There is evidence supporting the use of statins in the elderly. It is also likely that these drugs are under-used in this population.