Coronary artery stenting and non-cardiac surgery--a prospective outcome study

[Management of a high risk of thrombosis patient with drug-eluting stents undergoing a complete gastrectomy]

We report the case of a 70-year-old patient, with two drug-eluting stents (DES), scheduled for a complete gastrectomy for a gastric cancer. This case underlines management problems regarding a patient with a high risk of DES thrombosis in case of AAP withdrawal and a high risk of bleeding in case of AAP maintenance. At this time, no evidence-based recommendation is available for clinicians to manage these patients. Our strategy was therefore based on platelet function monitoring test, which is however neither available in clinical practice nor validated to predict haemorrhagic risk. Several biologic tests are under study; they could be useful to guide perioperative management of antiplatelet therapy in the clinical setting of surgical patients with DES.

The unresolved issues with risk stratification and management of patients with coronary artery disease undergoing major vascular surgery

PURPOSE

The purpose of this article, with a specific focus on patients undergoing vascular surgery, is to review controversial issues related to mechanisms of perioperative myocardial infarction (MI), coronary artery disease detection, and strategies to reduce perioperative complications. We propose explanations for the many conflicting results that have recently emerged in the literature.Source documents: We searched MEDLINE and reviewed all relevant manuscripts and scientific statements regarding management of patients undergoing non-cardiac surgery.

PRINCIPAL FINDINGS

Identification and prevention of ischemia in patients undergoing vascular surgery remains controversial. While the identification of preoperative ischemia is a marker of a higher perioperative risk, the value of identifying such ischemia has been questioned. We believe this may be, at least in part, due to our limited understanding of perioperative MI. Appropriate management of patients, based on the results of such testing, is likely the key to improving outcomes, and deserves further investigation. Efforts aimed at reducing the ischemic consequences of severe coronary plaques (by revascularization or beta-blocker therapy) have yielded conflicting results. The use of high doses of preoperative beta-blocker therapy may be harmful. Some studies suggest a promising role for statin therapy. Benefits of acetylsalicylic acid must be weighted against the risk of bleeding.

CONCLUSION

Many questions remain unanswered about the impact of detecting inducible ischemia, and the role of revascularization or beta-blockers in patients undergoing vascular surgery. A better understanding of the pathophysiology of perioperative MI is critical, in order to identify the best approach to improve cardiac outcomes in these patients.

[Perioperative discontinuation of antiplatelet therapy of patients with coronary stents. Reevaluating the risks]

According to the present guidelines, patients with coronary stents are to be treated with dual antiplatelet therapy. In case surgery is needed, the risk of a fatal stent thrombosis by withdrawing antithrombotics needs to be balanced in each individual case against the risk of haemorrhagic complications on continued antiplatelet medication. We present a case of fatal stent thrombosis and discuss the current evidence regarding perioperative continuation and interruption of antiplatelet therapy for this patient population. In summary the haemorrhagic risk with acetylsalicylic acid for secondary prevention seems very low, and it should be discontinued only in selected cases. Continued dual anticoagulation concepts are also discussed.

How to prevent perioperative myocardial injury: the conundrum continues

BACKGROUND

Perioperative myocardial injury (PMI) remains a major cause of perioperative morbidity and mortality but clinical strategies to prevent PMI are still uncertain.

METHODS AND RESULTS

We comprehensively searched PubMed for major research articles concerning clinical strategies to prevent PMI. The key findings are as follows: (1) the American College of Cardiology/American Heart Association guideline update for perioperative cardiovascular evaluation for noncardiac surgery is very useful to stratify cardiac risk preoperatively; (2) cardiac troponin has emerged as a biomarker to diagnose postoperative PMI and to predict clinical outcomes; (3) coronary revascularization before noncardiac surgery probably would provide cardiac protection in select patients, especially in patients with high-risk coronary artery disease; (4) elective noncardiac surgery should be postponed in patients who received coronary stenting recently because of high incidence of serious cardiac complications (minimum 6-8 weeks for bare metal stents and 6-12 months for drug-eluting stents); and (5) beta-blockers and statins are very promising drugs and probably would prevent PMI in a select patient population, especially in patients with intermediate risk and stable coronary artery disease.

CONCLUSIONS

Further studies, especially randomized clinical trials and mechanistic investigation are needed to find the best and effective clinical strategies to prevent/reduce PMI.

Discontinuation of antiplatelet therapy prior to low-risk noncardiac surgery in patients with drug-eluting stents: a retrospective cohort study

BACKGROUND

Drug-eluting coronary stents (DESs) pose a challenge in the perioperative period. Sirolimus and paclitaxel may inhibit reendothelialization of the traumatized vessel, making it vulnerable to platelet-mediated thrombosis. Given the anecdotal evidence and case series suggesting that DESs may be more vulnerable to thrombosis on discontinuation of antiplatelet agents than are bare-metal stents, we sought to quantify this risk.

METHODS

We linked the Cleveland Clinic Heart Center database with the Cleveland Clinic Internal Medicine Preoperative Assessment Consultation and Treatment (IMPACT) Center database to identify all patients who had undergone DES placement at the Cleveland Clinic and subsequently were evaluated for noncardiac surgery between July 2003 and July 2005. Outcome measures included 30-day rate of postoperative myocardial infarction (MI), DES thrombosis, major bleeding, and all-cause mortality.

RESULTS

We identified 114 patients who underwent noncardiac surgery a median of 236 days (IQR 125-354) after stent placement. Forty-five patients (40%) underwent surgery within 180 days of stenting, 15 of whom (13%) underwent surgery within 90 days of stenting. Eighty-eight patients (77%) discontinued all antiplatelet agents a median of 10 days before surgery. No patients died. Two patients (1.8%, 95% CI 0.5%-6.2%) suffered postoperative MIs, but postoperative catheterization showed neither had DES thrombosis (0%, 95% CI 0%-3.3%). One patient developed major bleeding (0.9%, CI 0.2%-4.8%).

CONCLUSIONS

These data suggest that the overall risk of stent thrombosis is low in low-risk noncardiac surgery patients with DESs, particularly those who have undergone at least 180 days of antiplatelet therapy, even after complete discontinuation of antiplatelet agents.

Perioperative antiplatelet therapy: the case for continuing therapy in patients at risk of myocardial infarction

Recent clinical data show that the risk of coronary thrombosis after antiplatelet drugs withdrawal is much higher than that of surgical bleeding if they are continued. In secondary prevention, aspirin is a lifelong therapy and should never be stopped. Clopidogrel is regarded as mandatory until the coronary stents are fully endothelialized, which takes 3 months for bare metal stents, but up to 1 yr for drug-eluting stents. Therefore, interruption of antiplatelet therapy 10 days before surgery should be revised. After reviewing the data on the use of antiplatelet drugs in cardiology and in surgery, we propose an algorithm for the management of patients, based on the risk of myocardial ischaemia and death compared with that of bleeding, for different types of surgery. Even if large prospective studies with a high degree of evidence are still lacking on different antiplatelet regimens during non-cardiac surgery, we propose that, apart from low coronary risk situations, patients on antiplatelet drugs should continue their treatment throughout surgery, except when bleeding might occur in a closed space. A therapeutic bridge with shorter-acting antiplatelet drugs may be considered.

[Coronary stents and anaesthesia]

The coronary stents are widely used to prevent coronary restenosis after percutaneous coronary intervention. Dual antiplatelet therapy (acetyl salicylic acid and a thienopyridine-clopidogrel or ticlopidine) are prescribed at least during six weeks after conventional stent and six months after drug eluting stent insertion to prevent stent thrombosis. When an invasive procedure is required, a risk of stent thrombosis arises after stopping antiplatelet therapy and a risk of bleeding when continuing this treatment. Therefore, cardiologists should choose carefully the type of coronary stent before insertion and concerned physicians (anaesthesiologists, surgeons, cardiologists) should decide a perioperative strategy in these high-risk patients.

A tale of two stents: perioperative management of patients with drug-eluting coronary stents

Drug-eluting stents were introduced into clinical practice to decrease coronary stent restenosis rates. Though remarkably effective in reducing this complication, recent data reveal that drug-eluting stents pose a significant risk for late stent thrombosis, an event strongly correlated with discontinuation of anti-platelet therapy. Because anti-platelet agents are often discontinued perioperatively, patients with DES are at risk for perioperative stent thrombosis and myocardial infarction. Along with a review of the recent literature, we present two cases of patients with drug-eluting stents scheduled for renal transplantation. Two distinct antithrombotic management strategies illustrate the risk of either approach-bleeding and transfusion versus stent thrombosis and myocardial infarction.

Prognostic impact of previous percutaneous coronary intervention in patients with diabetes mellitus and triple-vessel disease undergoing coronary artery bypass surgery

OBJECTIVES

In the current era of stent usage, percutaneous coronary intervention is more frequently performed as the initial revascularization strategy in multivessel disease before patients are finally referred to coronary artery bypass grafting. We sought to determine whether previous PCI has a prognostic impact on outcome in patients with diabetes mellitus and triple-vessel disease.

METHODS

Between January 2000 and March 2006, 621 consecutive patients with diabetes mellitus and triple-vessel disease undergoing isolated first-time coronary artery bypass grafting as the primary revascularization procedure (group 1) were evaluated for in-hospital mortality and major adverse cardiac events and compared with 128 patients with diabetes mellitus and triple-vessel disease treated during the same time period with previous percutaneous coronary intervention before coronary artery bypass grafting (group 2).

RESULTS

All-cause in-hospital mortality was 2.9% in group 1 and 7.8% in group 2 (odds ratio, 2.84; 95% confidence interval, 1.19-6.68; P = .02). In-hospital major adverse cardiac events were identified in 6.1% and 14.1% (odds ratio, 2.51; 95% confidence interval, 1.32-4.73; P < .005), respectively. Risk-adjusted multivariate logistic regression analysis of previous percutaneous coronary intervention significantly correlated with in-hospital mortality (odds ratio, 2.87; 95% confidence interval, 1.29-6.37; P = .03) and major adverse cardiac events (odds ratio, 2.54; 95% confidence interval, 1.39-4.62; P = .01). After computed propensity score matching based on 12 major preoperative risk factors to control selection bias, conditional regression analysis confirmed previous percutaneous coronary intervention to be associated with all-cause in-hospital mortality (odds ratio, 2.97; 95% confidence interval, 1.12-7.86; P = .03) and major adverse cardiac events (odds ratio, 2.46; 95% confidence interval, 1.18-5.15; P = .02) in these patients.

CONCLUSION

Previous percutaneous coronary intervention before coronary artery bypass grafting in patients with diabetes mellitus and triple-vessel disease independently increases the risk for in-hospital mortality and major adverse cardiac events.

Coronary artery stents and non-cardiac surgery

The utility of interventional cardiology has developed significantly over the last two decades with the introduction of coronary angioplasty and stenting, with the associated antiplatelet medications. Acute coronary stent occlusion carries a high morbidity and mortality, and the adoption of therapeutic strategies for prophylaxis against stent thrombosis has major implications for surgeons and anaesthetists involved in the management of these patients in the perioperative period. Currently, there is limited published information to guide the clinician in the optimal care of patients who have had coronary stents inserted when they present for non-cardiac surgery. This review examines the available literature on the perioperative management of these patients. A number of key issues are identified: the role of surgery vs percutaneous coronary intervention for coronary revascularization in the preoperative period; the different types of coronary stents currently available; the emerging issues related to drug-eluting stents; the pathophysiology of coronary stent occlusion; and the recommended antiplatelet regimes that the patient with a coronary stent will be receiving. The role of preoperative platelet function testing is also discussed, and the various available tests are listed. Appropriate management by all the clinicians involved with patients with coronary stents undergoing a variety of non-cardiac surgical procedures is essential to avoid a high incidence of postoperative cardiac mortality and morbidity. The review examines the evidence available for the perioperative strategies aimed at reducing adverse outcomes in a number of different clinical scenarios.

Perioperative use of anti-platelet drugs

Performing a surgical procedure on a patient undergoing anti-platelet therapy raises a dilemma: is it safer to withdraw the drugs and reduce the haemorrhagic risk, or to maintain them and reduce the risk of myocardial ischaemic events? Based on recent clinical data, this review concludes that the risk of coronary thrombosis on anti-platelet drugs withdrawal is much higher than the risk of surgical bleeding when maintaining them. In secondary prevention, aspirin is a lifelong therapy and should never be stopped. Clopidogrel is mandatory as long as the coronary stents are not fully endothelialized, which takes 6-24 weeks depending on the technique used, but might be required for a longer period.

Management of patients with cardiac stents undergoing noncardiac surgery

PURPOSE OF REVIEW

Coronary stenting is performed in over 4 million patients annually. Approximately 5% of these patients undergo a noncardiac surgical procedure within 1 year after stenting. Surgery might induce hypercoagulability. This causes increased concern about the effects of previous coronary stenting on postoperative cardiac outcome, particularly in-stent thrombosis. On the other hand, patients with multiple cardiac risk factors are at high risk for postoperative adverse cardiac events and might even benefit from preoperative prophylactic coronary revascularization.

RECENT FINDINGS

Early noncardiac surgery after coronary stent placement is associated with an increased risk of major adverse cardiac events. The majority of these events are attributable to in-stent thrombosis. Antiplatelet therapy interruption in the perioperative period seems to be associated with an increase in adverse cardiac events, particularly in patients who undergo noncardiac surgery early after coronary stenting. Furthermore, prophylactic coronary revascularization for high cardiac risk patients is not associated with an improved outcome.

SUMMARY

Early noncardiac surgery after coronary stenting increases the risk of postoperative cardiac events. Interruption of antiplatelet therapy seems to play an important role in this increased event rate. Prophylactic coronary revascularization in cardiac stable, but high-risk patients does not seem to improve outcome.

Perioperative Management of Patients With Coronary Stents

Perioperative coronary stent thrombosis is a catastrophic complication that can occur in patients receiving both bare-metal and drug-eluting stents. Noncardiac surgery appears to increase the risk that recently-placed stents thrombose, especially when surgery is performed early after stenting, and particularly if dual antiplatelet therapy is discontinued. We reviewed the existing data about the frequency of stent thrombosis after noncardiac surgery and explored the impact of delay from surgery and discontinuation of antiplatelet therapy. We also reviewed the data about the impact of preoperative revascularization in patients known to require noncardiac surgery. Based on these published data, we offer recommendations that can be used to guide the treatment of patients who require noncardiac surgery after having received a stent.

Preoperative cardiac risk stratification 2007: evolving evidence, evolving strategies

Various guidelines and risk indices have optimized cardiac risk stratification, and the emphasis has shifted to reducing perioperative risk. This review is an update on invasive (CABG/PCI) and noninvasive (medical therapy with beta-blockers, alpha-agonists, and statins) strategies to reduce cardiac risk for noncardiac surgery and the controversies surrounding their use.

Koronare Stents, duale Antiplättchentherapie und die perioperative Problematik

Up to 90% of all percutaneous coronary interventions include coronary artery stenting. Dual antiplatelet therapy, usually involving acetylsalicyl acid combined with clopidogrel, is mandatory for patients with coronary artery stents. The duration of antiplatelet therapy for bare metal stents is 3-4 weeks, for drug eluting stents 6-12 months. Preoperative discontinuation of both drugs increases the risk of stent thrombosis, continuation the risk of relevant bleeding. According to the recommendations of anaesthesiological and cardiological societies, perioperative management has to balance the risk of bleeding vs stent thrombosis. Surgery involving a high risk of bleeding can require the discontinuance of both substances. In cases of high thrombosis risk, at least the acetylsalicyl acid should be continued until the day of surgery. For patients under antiplatelet therapy scheduled for local anaesthesia, national recommendations exist. A close collaboration between the anaesthesiologist, cardiologist and surgeon is essential for appropriate pre-, intra- and postoperative management.

Perioperative Kardioprotektion

Myocardial ischemia is a major cause of perioperative morbidity and mortality. Because of a growing expectancy of lives, the prevalence of cardiovascular diseases is increasing, and thus the number of surgical patients presenting with a cardiovascular risk profile. Based upon pathophysiological considerations, different interventions to lower perioperative cardiovascular risk have been evaluated. The mostly discussed intervention believed to prevent cardiovascular complications in the perioperative period is the use of beta-blockers. Although many authors agree that perioperative beta-blockade is effective in high-risk patients, less is known about the optimal timing, dosage and the identification of patients in whom the intervention would be beneficial. Based upon the available data we try to answer questions about timing and dosage, and we discuss possible side effects and economic questions. Another cardioprotective option is the use of statins. Besides their lipid-lowering properties, so called pleiotropic effects are believed to decrease cardiac risk. Furthermore, different interventions can be used in addition to or as an alternative to perioperative beta-blocker therapy, such as alpha-2 agonists, thoracic epidural analgesia or coronary revascularization.

[Coronary stents and anaesthesia: it is time to have national data]

We report 13 cases of coronary stent patients, undergoing a non cardiac surgery. Despite an heterogenous perioperative management of antiplatelet agents, none of these patients developed any significant complications. Recently, several case reports of postoperative drug eluting stent thrombosis have been reported. However, the actual incidence of this dramatic event is not known. This confirms the need to perform prospective studies or registries of patients with coronary stents undergoing non cardiac surgery, in order to propose evidence-based recommendations on perioperative antiplatelet management in such patients.