Simvastatin Reduces CD40 Expression in an Experimental Model of Early Arterialization of Saphenous Vein Graft

Preventing treatment failures in coronary artery disease: what can we learn from the biology of in-stent restenosis, vein graft failure, and internal thoracic arteries?

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and the availability of percutaneous or surgical revascularization procedures significantly improves survival. However, both strategies are daunted by complications which limit long-term effectiveness. In-stent restenosis (ISR) is a major drawback for intracoronary stenting, while graft failure is the limiting factor for coronary artery bypass graft surgery (CABG), especially using veins. Conversely, internal thoracic artery (ITA) is known to maintain long-term patency in CABG. Understanding the biology and pathophysiology of ISR and vein graft failure (VGF) and mechanisms behind ITA resistance to failure is crucial to combat these complications in CAD treatment. This review intends to provide an overview of the biological mechanisms underlying stent and VGF and of the potential therapeutic strategy to prevent these complications. Interestingly, despite being different modalities of revascularization, mechanisms of failure of stent and saphenous vein grafts are very similar from the biological standpoint.

The effects of preoperative statins on the incidence of postoperative acute kidney injury in patients undergoing cardiac surgeries

OBJECTIVES

Recent evidence has emphasized multifunctional therapeutic effects of statins on renal protection after cardiac surgeries. We aimed to assess the effects of preoperative administration of statins on lowering the incidence of postoperative acute kidney injury in patients undergoing cardiac surgeries.

METHODS

In a retrospective study, the preoperative, intraoperative and postoperative data of 1064 consecutive patients who underwent different forms of cardiovascular surgeries were reviewed. According to whether patients had received statins preoperatively, the patients were categorized into no statin (n = 620), low-dose statin (n = 262) or high-dose statin (n = 182) administration groups.

RESULTS

No difference was seen in postoperative incidence of acute kidney injury between the three groups (11.1, 9.9 and 11.5%, respectively, P = 0.887). The multivariate logistic regression analysis showed that advanced age [odds ratio (OR) = 1.043, P < 0.001], recent myocardial infarction within 90 days of surgery (OR = 1.935, P = 0.002) and longer intubation time (OR = 1.001, P = 0.001) could predict occurrence of kidney injury after cardiac surgery. The preoperative use of angiotensin converting enzyme (ACE) inhibitor could effectively prevent occurrence of this postoperative event (OR = 0.552, P = 0.008). After adjusting for propensity score only, statin treatment, at low or high doses, was not associated with lower postoperative acute kidney injury (OR = 1.010, P = 0.971 for low dose and OR = 1.108, P = 0.745 for high dose versus no statin). After further adjustment for propensity score, statin treatment with the different dosages was not associated with acute kidney injury (OR = 0.869, P = 0.633 for low dose and OR = 1.051, P = 0.885 for high dose versus no statin).

CONCLUSIONS

Preoperative statin use may not inhibit acute kidney injury after operation.

Fatal early peripheral post-reperfusion syndrome and the role of cutaneous signs

The purpose of this report is to present the case of a 75-year-old male affected by right common femoral artery and abdominal aortic aneurysms. His clinical history was also characterised by post-ischaemic cardiomyopathy, arterial hypertension, chronic respiratory disease and peripheral arterial disease. We performed two surgical procedures: right femoral aneurysmectomy and femoro-femoral bypass and subsequently a femoro-femoral crossover bypass plus right femoro-popliteal bypass below the knee. The second operation became necessary in order to treat acute occlusion of the right iliac-femoral arterial axis. The patient developed a progressive and aggressive lower limb post-perfusion syndrome associated to frank peripheral oedema, myocardial stunning, reperfusion arrhythmias, renal failure and respiratory distress. Cutaneous alterations (oedema of the leg, mottled skin and cyanosis of the foot) were more specific compared with Doppler ultrasound that showed the presence of adequate blood flow in the early phase. On the basis of this experience and of pertinent literature, this study represents a challenge for the understanding of the exact mechanism of origin and progression of post-reperfusion syndrome.

Statins and vein graft failure in coronary bypass surgery

Saphenous vein grafts used in coronary artery bypass graft surgery suffer from lower patency rates compared to left internal mammary artery. A number of clinical trials and observational studies have demonstrated a significant benefit of statin treatment on vein graft patency. Aside from their well-known lipid-lowering capacities, statins exert pleiotropic effects by direct inhibition of the mevalonate pathway in the wall of these grafts. This leads to reduced geranylgeranylation of small GTPases such as Rho and Rac. Through this LDL-independent mechanism, statins improve endothelial function and reduce vascular inflammation and oxidative stress, inhibiting also smooth muscle cell proliferation and migration. Although the existing evidence supports a beneficial effect of statins on vein grafts biology, more clinical trials focused on the effect of aggressive statin treatment on vein graft patency are required, in order to safely translate this strategy into clinical practice.

Statins: a new pharmacological agent for free flap surgery?

Microvascular free tissue transfer has become the standard for reconstruction in head and neck oncological surgery. Several pharmacological agents have been used in order to increase the success rate of this surgery, but there is currently no consensus for an ideal drug. We review the literature concerning the complications encountered in free flap surgery related to the ischaemia-reperfusion injury and detail the effects of statins relevant to this endothelial dysfunction. Statins, because of their pleiotropic effects such as preservation of vascular tone, anticoagulation and anti-inflammatory properties, appear to be useful in free flap surgery. This study highlights the benefits of statins in order to increase the success rate and the quality of the free flap. They should be included in the perioperative strategy, especially in patients with cardiovascular risk factors. A protocol is presented.