Angiographic correlates of cardiac death and myocardial infarction complicating major nonthoracic vascular surgery

Validation of Perioperative Troponin Levels for Predicting Postoperative Mortality and Long-Term Survival in Patients Undergoing Surgery for Hepatobiliary and Pancreatic Cancer

Background: Hepatopancreato and biliary (HPB) tumors represent some of the leading cancer-related causes of death worldwide, with the majority of patients undergoing surgery in the context of a multimodal treatment strategy. Consequently, the implementation of an accurate risk stratification tool is crucial to facilitate informed consent, along with clinical decision making, and to compare surgical outcomes among different healthcare providers for either service evaluation or clinical audit. Perioperative troponin levels have been proposed as a feasible and easy-to-use tool in order to evaluate the risk of postoperative myocardial injury and 30-day mortality. The purpose of the present study is to validate the perioperative troponin levels as a prognostic factor regarding postoperative myocardial injury and 30-day mortality in Greek adult patients undergoing HPB surgery. Method: In total, 195 patients undergoing surgery performed by a single surgical team in a single tertiary hospital (2020-2022) were included. Perioperative levels of troponin before surgery and at 24 and 48 h postoperatively were assessed. Model accuracy was assessed by observed-to-expected (O:E) ratios, and area under the receiver operating characteristic curve (AUC). Survival at one year postoperatively was compared between patients with high and normal TnT levels at 24 h postoperatively. Results: Thirteen patients (6.6%) died within 30 days of surgery. TnT levels at 24 h postoperatively were associated with excellent discrimination and provided the best-performing calibration. Patients with normal TnT levels at 24 h postoperatively were associated with higher long-term survival compared to those with high TnT levels. Conclusions: TnT at 24 h postoperatively is an efficient risk assessment tool that should be implemented in the perioperative pathway of patients undergoing surgery for HPB cancer.

Antiplatelet therapy and long-term mortality in patients with myocardial injury after non-cardiac surgery

BACKGROUNDS

Myocardial injury after non-cardiac surgery (MINS) has recently been accepted as a common complication associated with increased mortality. However, little is known about the treatment of MINS. The aim of this study was to investigate an association between antiplatelet therapy and long-term mortality after MINS.

METHODS

From 2010 to 2019, patients with MINS, defined as having a peak high-sensitivity troponin I higher than 40 ng/L within 30 days after non-cardiac surgery, were screened at a tertiary centre. Patients were excluded if they had a history of coronary revascularisation before or during index hospitalisation. Clinical outcomes at 1 year were compared between patients with and without antiplatelet therapy at hospital discharge. The primary outcome was death, and the secondary outcome was major bleeding.

RESULTS

Of the 3818 eligible patients with MINS, 940 (24.6%) received antiplatelet therapy at hospital discharge. Patients with antiplatelet therapy had a significantly lower mortality at 1 year than those without antiplatelet therapy (7.5% vs 15.9%, adjusted HR 0.60, 95% CI 0.45 to 0.79, p<0.001). A risk of major bleeding at 1 year was not significantly different between the patients with and without antiplatelet therapy (6.6% vs 7.6%, adjusted HR 0.85, 95% CI 0.62 to 1.17, p=0.324). In propensity score-matched analysis of 886 pairs, patients with antiplatelet therapy had a significantly lower risk of 1-year mortality (adjusted HR 0.53, 95% CI 0.39 to 0.73, p<0.001) than those without antiplatelet therapy.

CONCLUSIONS

In patients with MINS, antiplatelet therapy at discharge was associated with decreased 1-year mortality.

Myocardial injury after major non-cardiac surgery evaluated with advanced cardiac imaging: a pilot study

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) is a frequent complication caused by cardiac and non-cardiac pathophysiological mechanisms, but often it is subclinical. MINS is associated with increased morbidity and mortality, justifying the need to its diagnose and the investigation of their causes for its potential prevention.

METHODS

Prospective, observational, pilot study, aiming to detect MINS, its relationship with silent coronary artery disease and its effect on future adverse outcomes in patients undergoing major non-cardiac surgery and without postoperative signs or symptoms of myocardial ischemia. MINS was defined by a high-sensitive cardiac troponin T (hs-cTnT) concentration > 14 ng/L at 48-72 h after surgery and exceeding by 50% the preoperative value; controls were the operated patients without MINS. Within 1-month after discharge, cardiac computed tomography angiography (CCTA) and magnetic resonance imaging (MRI) studies were performed in MINS and control subjects. Significant coronary artery disease (CAD) was defined by a CAD-RADS category ≥ 3. The primary outcomes were prevalence of CAD among MINS and controls and incidence of major cardiovascular events (MACE) at 1-year after surgery. Secondary outcomes were the incidence of individual MACE components and mortality.

RESULTS

We included 52 MINS and 12 controls. The small number of included patients could be attributed to the study design complexity and the dates of later follow-ups (amid COVID-19 waves). Significant CAD by CCTA was equally found in 20 MINS and controls (30% vs 33%, respectively). Ischemic patterns (n = 5) and ischemic segments (n = 2) depicted by cardiac MRI were only observed in patients with MINS. One-year MACE were also only observed in MINS patients (15.4%).

CONCLUSION

This study with advanced imaging methods found a similar CAD frequency in MINS and control patients, but that cardiac ischemic findings by MRI and worse prognosis were only observed in MINS patients. Our results, obtained in a pilot study, suggest the need of further, extended studies that screened systematically MINS and evaluated its relationship with cardiac ischemia and poor outcomes. Trial registration Clinicaltrials.gov identifier: NCT03438448 (19/02/2018).

Prognosis of Myocardial Injury After Non-Cardiac Surgery in Adults Aged Younger Than 45 Years

BACKGROUND

This study compared myocardial injury after non-cardiac surgery (MINS) and mortalities between patients under and over the age of 45 years.Methods and Results:From January 2010 and June 2019, patients with cardiac troponin measurement within 30 days after non-cardiac surgery were enrolled and divided into groups according to age: >45 (≥45 years) and <45 (<45 years). Further analyses were conducted only in patients who were diagnosed with MINS. The outcomes were MINS and 30-day mortality. Of the 35,223 patients, 31,161 (88.5%) patients were in the >45-year group and 4,062 (11.5%) were in the <45-year group. After adjustment with inverse probability of weighting, the <45-years group showed a lower incidence of MINS and cardiovascular mortality (16.6% vs. 11.7%; odds ratio, 0.77; 95% confidence interval [CI], 0.69-0.84; P<0.001 and 0.4% vs. 0.2%; hazard ratio [HR], 0.41; 95% CI, 0.19-0.88; P=0.02, respectively). In a comparison of only the <45-years group, MINS was associated with increased 30-day mortality (0.7% vs. 10.3%; HR, 10.48; 95% CI, 6.18-17.78; P<0.001), but the mortalities of patients with MINS did not differ according to age.

CONCLUSIONS

MINS has a comparable prognostic impact in patients aged under and over 45 years; therefore, future studies need to also consider patients aged <45 years regarding risk factors of MINS and screening of perioperative troponin elevation.

Non-cardiac surgery in patients with coronary artery disease: risk evaluation and periprocedural management

Perioperative cardiovascular complications are important causes of morbidity and mortality associated with non-cardiac surgery, particularly in patients with coronary artery disease (CAD). Although preoperative cardiac risk assessment can facilitate the identification of vulnerable patients and implementation of adequate preventive measures, excessive evaluation might lead to undue resource utilization and surgical delay. Owing to conflicting data, there remains some uncertainty regarding the most beneficial perioperative strategy for patients with CAD. Antithrombotic agents are the cornerstone of secondary prevention of ischaemic events but substantially increase the risk of bleeding. Given that 5-25% of patients undergoing coronary stent implantation require non-cardiac surgery within 2 years, surgery is the most common reason for premature cessation of dual antiplatelet therapy. Perioperative management of antiplatelet therapy, which necessitates concomitant evaluation of the individual thrombotic and bleeding risks related to both clinical and procedural factors, poses a recurring dilemma in clinical practice. Current guidelines do not provide detailed recommendations on this topic, and the optimal approach in these patients is yet to be determined. This Review summarizes the current data guiding preoperative risk stratification as well as periprocedural management of patients with CAD undergoing non-cardiac surgery, including those treated with stents.

Perioperative cardiovascular complications rate and activity of coagulation and fibrinolysis among patients undergoing vascular surgery for peripheral artery disease and abdominal aortic aneurysm

OBJECTIVES

To compare preoperative coagulation and fibrinolysis activity and incidence of perioperative complications between patients undergoing vascular procedures for peripheral artery disease and abdominal aortic aneurysm.

METHODS

This is a substudy of a prospective observational cohort study (VISION; NCT00512109) in which we recruited patients aged ≥45 years, undergoing surgery for peripheral artery disease and abdominal aortic aneurysm. Blood samples were obtained 24 h preoperatively to measure platelet count, concentrations of coagulation coagulation (fibrinogen, factor VIII, von Willebrand factor:Ristocetin cofactor, antithrombin III), fibrinolysis (dimer D, plasmin-antiplasmin complexes, tissue plasminogen activator) markers and level of soluble CD40 ligand. Incidence of myocardial infarction, stroke, and death (composite endpoint) was assessed in 30-day follow-up.

RESULTS

The study group included 131 patients at the mean age of 68.3 years among whom reason for surgery was peripheral artery disease in 77 patients (58.8%) and abdominal aortic aneurysm in 54 patients (41.2%). Peripheral artery disease group was characterized by higher platelet count (250.5 versus 209.5 (×10³/µl), p = 0.001), concentrations of fibrinogen (5.4 versus 4.1 (g/l), p < 0.001), factor VIII (176.9 versus 141.9 (%), p < 0.001), von Willebrand factor:Ristocetin cofactor (188.9 versus 152.3 (%), p = 0.009), and soluble CD40 ligand (9016.0 versus 7936.6 (pg/ml), p = 0.005). The dimer D level was higher (808.0 versus 2590.5 (ng/ml), p < 0.001) in the abdominal aortic aneurysm group. Incidence of major cardiovascular events (death, myocardial infarction, stroke) within 30 days from surgery did not differ between the groups (39.0% versus 29.6%, p = 0.27).

CONCLUSIONS

The study suggests higher activation of coagulation and relatively lower fibrinolytic activity in peripheral artery disease group compared to patients undergoing surgery for abdominal aortic aneurysm without a significant difference in cardiovascular outcomes.

Chronic Kidney Disease and Coronary Artery Disease: JACC State-of-the-Art Review

Chronic kidney disease (CKD) is a major risk factor for coronary artery disease (CAD). As well as their high prevalence of traditional CAD risk factors, such as diabetes and hypertension, persons with CKD are also exposed to other nontraditional, uremia-related cardiovascular disease risk factors, including inflammation, oxidative stress, and abnormal calcium-phosphorus metabolism. CKD and end-stage kidney disease not only increase the risk of CAD, but they also modify its clinical presentation and cardinal symptoms. Management of CAD is complicated in CKD patients, due to their likelihood of comorbid conditions and potential for side effects during interventions. This summary of the Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference on CAD and CKD (including end-stage kidney disease and transplant recipients) seeks to improve understanding of the epidemiology, pathophysiology, diagnosis, and treatment of CAD in CKD and to identify knowledge gaps, areas of controversy, and priorities for research.

Perioperative Heart-Brain Axis Protection in Obese Surgical Patients: The Nutrigenomic Approach

The number of obese patients undergoing cardiac and noncardiac surgery is rapidly increasing because they are more prone to concomitant diseases, such as diabetes, thrombosis, sleep-disordered breathing, cardiovascular and cerebrovascular disorders. Even if guidelines are already available to manage anesthesia and surgery of obese patients, the assessment of the perioperative morbidity and mortality from heart and brain disorders in morbidly obese surgical patients will be challenging in the next years. The present review will recapitulate the new mechanisms underlying the Heart-brain Axis (HBA) vulnerability during the perioperative period in healthy and morbidly obese patients. Finally, we will describe the nutrigenomics approach, an emerging noninvasive dietary tool, to maintain a healthy body weight and to minimize the HBA propensity to injury in obese individuals undergoing all types of surgery by personalized intake of plant compounds that may regulate the switch from health to disease in an epigenetic manner. Our review provides current insights into the mechanisms underlying HBA response in obese surgical patients and how they are modulated by epigenetically active food constituents.

Preoperative biomarker evaluation for the prediction of cardiovascular events after major vascular surgery

OBJECTIVE

The cause of perioperative myocardial infarction (PMI) is postulated to involve hemodynamic stress or coronary plaque destabilization. We aimed to evaluate perioperative factors in patients with peripheral artery disease (PAD) undergoing major vascular surgery to determine the likely mechanisms and predictors of PMI.

METHODS

This was a prospective cohort study of 133 patients undergoing major vascular surgery including open abdominal aortic aneurysm (AAA) repair (n = 40) and major suprainguinal or infrainguinal arterial bypasses (non-AAA; n = 93). Preoperative assessment with history, physical examination, and peripheral artery tonometry was performed in addition to plasma sampling of biomarkers associated with inflammation and coronary plaque instability. The primary outcome was occurrence of a 30-day cardiovascular event (CVE; composite of PMI [troponin I elevation >99th percentile reference of ≥0.1 μg/L], stroke, or death).

RESULTS

Of 133 patients, 36 patients (27%) developed a 30-day CVE after vascular surgery, and all were PMI. Patients with 30-day CVE were older (75 ± 8 years vs 69 ± 10 years, mean ± standard deviation; P = .001), had higher prevalence of hypertension (94% vs 79%; P = .01) and preoperative beta-blocker therapy (50% vs 29%; P = .02), and had longer duration of surgery (5.1 ± 1.8 hours vs 4.0 ± 1.1 hours; P < .0001). Significant elevations in cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), troponin I, high-sensitivity troponin T, matrix metalloproteinase 3, and osteoprotegerin occurred in those who developed 30-day CVE (all P < .05). Multivariate binary logistic regression identified AAA surgery and log-transformed NT-proBNP to be independent preoperative predictors of 30-day CVE (area under the receiver operating characteristic curve = 0.81).

CONCLUSIONS

In patients with peripheral artery disease undergoing major vascular surgery, the likely mechanism of PMI appears to be the hemodynamic stress related to the type and duration of surgery. NT-proBNP was a useful independent predictor of CVE and thus may serve as an important biomarker of cardiovascular fitness for surgery.

Etiology of Acute Coronary Syndrome after Noncardiac Surgery

BACKGROUND

The objective of this investigation was to determine the etiology of perioperative acute coronary syndrome with a particular emphasis on thrombosis versus demand ischemia.

METHODS

In this retrospective cohort study, adult patients were identified who underwent coronary angiography for acute coronary syndrome within 30 days of noncardiac surgery at a major tertiary hospital between January 2008 and July 2015. Angiograms were independently reviewed by two interventional cardiologists who were blinded to clinical data and outcomes. Acute coronary syndrome was classified as ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, or unstable angina; myocardial infarctions were adjudicated as type 1 (plaque rupture), type 2 (demand ischemia), or type 4b (stent thrombosis).

RESULTS

Among 215,077 patients screened, 146 patients were identified who developed acute coronary syndrome: 117 were classified as non-ST-elevation myocardial infarction (80.1%); 21 (14.4%) were classified as ST-elevation myocardial infarction, and 8 (5.5%) were classified as unstable angina. After coronary angiography, most events were adjudicated as demand ischemia (type 2 myocardial infarction, n = 106, 72.6%) compared to acute coronary thrombosis (type 1 myocardial infarction, n = 37, 25.3%) and stent thrombosis (type 4B, n = 3, 2.1%). Absent or only mild, nonobstructive coronary artery disease was found in 39 patients (26.7%). In 14 patients (9.6%), acute coronary syndrome was likely due to stress-induced cardiomyopathy. Aggregate 30-day and 1-yr mortality rates were 7 and 14%, respectively.

CONCLUSIONS

The dominant mechanism of perioperative acute coronary syndrome in our cohort was demand ischemia. A subset of patients had no evidence of obstructive coronary artery disease, but findings were consistent with stress-induced cardiomyopathy.

Remote Ischemic Conditioning: A Clinical Trial’s Update

Coronary artery disease (CAD) is the leading cause of death and disability worldwide, and early and successful restoration of myocardial reperfusion following an ischemic event is the most effective strategy to reduce final infarct size and improve clinical outcome. This process can, however, induce further myocardial damage, namely acute myocardial ischemia-reperfusion injury (IRI) and worsen clinical outcome. Therefore, novel therapeutic strategies are required to protect the myocardium against IRI in patients with CAD. In this regard, the endogenous cardioprotective phenomenon of “ischemic conditioning,” in which the heart is put into a protected state by subjecting it to one or more brief nonlethal episodes of ischemia and reperfusion, has the potential to attenuate myocardial injury during acute IRI. Intriguingly, the heart can be protected in this manner by applying the “ischemic conditioning” stimulus to an organ or tissue remote from the heart (termed remote ischemic conditioning or RIC). Furthermore, the discovery that RIC can be noninvasively applied using a blood pressure cuff on the upper arm to induce brief episodes of nonlethal ischemia and reperfusion in the forearm has greatly facilitated the translation of RIC into the clinical arena. Several recently published proof-of-concept clinical studies have reported encouraging results with RIC, and large multicenter randomized clinical trials are now underway to investigate whether this simple noninvasive and virtually cost-free intervention has the potential to improve clinical outcomes in patients with CAD. In this review article, we provide an update of recently published and ongoing clinical trials in the field of RIC.

Postoperative Cardiac Ischemia Detection by Continuous 12-Lead Electrocardiographic Monitoring in Vascular Surgery Patients: A Prospective, Observational Study

OBJECTIVES

Elderly patients undergoing vascular surgery are at major risk for perioperative cardiac complications. The authors investigated continuous electrocardiographic Holter monitoring in a postoperative setting to determine the degree of postoperative ischemic load and its possible associations with perioperative myocardial infarction.

DESIGN

A prospective, observational study.

SETTING

One university hospital.

PARTICIPANTS

The study comprised 51 patients aged 65 years or older undergoing peripheral arterial surgery.

INTERVENTIONS

Continuous electrocardiographic monitoring with a Holter device was started postoperatively and continued for 72 hours or until discharge. Postural changes were recorded using a 3-axis accelerometer. Standard 12-lead electrocardiography, high-sensitive troponin T measurements, and an inquiry of ischemic symptoms were performed 4 times perioperatively.

MEASUREMENTS AND MAIN RESULTS

The primary outcomes were ischemic load (area under the function of ischemic ST-segment deviation and ischemic time) and perioperative myocardial infarction. During 3,262.7 patient-hours of monitoring, 17 patients (33.3%) experienced 608 transient ischemic events, all denoted by ST-segment depression. Of these 17 patients, 5 experienced perioperative myocardial infarction. The mean ischemic load in all patients was 913.2±2,797.3 µV×minute. Ischemic load predicted perioperative myocardial infarction, with an area under receiver operating characteristics curve (95% confidence interval) of 0.87 (0.75-0.99). Ischemic changes occurred most frequently during hours 24 to 60 of monitoring. Ischemia was asymptomatic in 14 of 17 patients (82.4%).

CONCLUSION

Postoperative myocardial ischemia was common in peripheral vascular surgery patients and may progress to perioperative myocardial infarction. Ischemic load was a good predictor of perioperative myocardial infarction. Ambulatory electrocardiographic monitoring solutions for continuous postoperative ischemia detection are warranted in the surgical ward.

Role of prophylactic coronary revascularisation in improving cardiovascular outcomes during non-cardiac surgery: A narrative review

Coronary revascularisation has been a topic of debate for over three decades in patients undergoing high-risk non-cardiac surgery. The paradigm shifted from routine coronary angiography toward stress test guided decision-making based on larger randomised trials. However, this paradigm is challenged by relatively newer data where routine coronary angiography and revascularisation is shown to improve perioperative cardiovascular outcomes. We review major studies performed over a long period including more contemporary data with regard to the 2014 American College of Cardiology/American Heart Association as well as 2014 European Society of Cardiology guideline on perioperative cardiovascular evaluation of patients undergoing non-cardiac surgery.

Perioperative Diastolic Dysfunction in Patients Undergoing Noncardiac Surgery Is an Independent Risk Factor for Cardiovascular Events

Background

The prognostic value of perioperative diastolic dysfunction (PDD) in patients undergoing noncardiac surgery remains uncertain, and the current guidelines do not recognize PDD as a perioperative risk factor. This systematic review aimed to investigate whether existing evidence supports PDD as an independent predictor of adverse events after noncardiac surgery.

Methods

Ovid MEDLINE, PubMed, EMBASE, the Cochrane Library, and Google search engine were searched for English-language citations in April 2015 investigating PDD as a risk factor for perioperative adverse events in adult patients undergoing noncardiac surgery. Two reviewers independently assessed the study risk of bias. Extracted data were verified. Random-effects model was used for meta-analysis, and reviewers’ certainty was graded.

Results

Seventeen studies met eligibility criteria; however, 13 contributed to evidence synthesis. The entire body of evidence addressing the research question was based on a total of 3,876 patients. PDD was significantly associated with pulmonary edema/congestive heart failure (odds ratio [OR], 3.90; 95% CI, 2.23 to 6.83; 3 studies; 996 patients), myocardial infarction (OR, 1.74; 95% CI, 1.14 to 2.67; 3 studies; 717 patients), and the composite outcome of major adverse cardiovascular events (OR, 2.03; 95% CI, 1.24 to 3.32; 4 studies; 1,814 patients). Evidence addressing other outcomes had low statistical power, but higher long-term cardiovascular mortality was observed in patients undergoing open vascular repair (OR, 3.00; 95% CI, 1.50 to 6.00). Reviewers’ overall certainty of the evidence was moderate.

Conclusion

Evidence of moderate certainty indicates that PDD is an independent risk factor for adverse cardiovascular outcomes after noncardiac surgery.

Diagnosis, Incidence, and Clinical Implications of Perioperative Myocardial Injury in Vascular Surgery

Introduction:

Routine measurement of cardiac biomarkers such as troponin T (TnT) is recommended perioperatively, especially in high-risk vascular surgery. Long-term prognosis is worse even in those with nonspecific perioperative myocardial injury. However, a clear understanding of these biomarker profiles and how they should affect patient management is lacking.

Methods:

We examined the perioperative profile of high-sensitivity TnT (hsTnT) release in 85 patients undergoing elective major vascular surgery. Plasma hsTnT was measured preoperatively, at 6, 12, and 24 hours postoperatively, and then every 24 hours for a maximum of 5 days. Significant elevations in hsTnT with/without clinical indicators of ischemia were used to diagnose myocardial infarction or injury.

Results:

A high incidence of myocardial injury was evident (46% had elevated hsTnT); only 5% were associated with myocardial infarction, and 41% were due to myocardial injury.

Conclusions:

This study emphasizes the high incidence of perioperative myocardial injury and stress in vascular surgery as revealed by the use of the robust and very sensitive biomarker of myocardial damage, hsTnT. The high availability and swift development of increasingly sensitive assays allow detection of abnormal elevated hsTnT levels in a higher proportion of the population. Consequent challenges are the reduced specificity to separate acute events as well as to deduce the prognostic value of elevations due to confusing criteria; this is especially the case in a patient group with multiple comorbidities that affect hsTnT levels chronically.

Perioperative clinical variables and long-term survival following vascular surgery

Cardiovascular disease is the leading cause of death in patients with peripheral arterial disease (PAD). Coronary artery disease (CAD) is highly prevalent, and often times coexist, in patients with PAD. The management of patients with PAD that requires a high-risk vascular surgical procedure for intermittent claudication, critical limb ischemia or expanding abdominal aortic aneurysm requires risk stratification with the revised cardiac risk index, optimization of medical therapies, and limited use of cardiac imaging prior to surgery. Preventive revascularization in patients with stable CAD, with the sole intention to mitigate the risk of cardiac complications in the peri-operative period, is not effective and may be associated with significant bleeding and thrombotic risks, in particular if stents are used. A strategy of universal use of cardiac troponins in the perioperative period for active surveillance of myocardial ischemia may be more reasonable and cost-effective than the current standard of care of widespread use of cardiac imaging prior to high-risk surgery. An elevated cardiac troponin after vascular surgery is predictive of long-term mortality risk. Medical therapies such as aspirin and statins are recommended for patients with post-operative myocardial ischemia. Ongoing trials are assessing the role of novel anticoagulants. Additional research is needed to define the role of cardiac imaging and invasive angiography in this population.

Cardiovascular risk assessment in kidney transplantation

Cardiovascular disease (CVD) remains the most common cause of death after kidney transplantation worldwide, with the highest event rate in the early postoperative period. In an attempt to address this issue, screening for CVD prior to transplant is common, but the clinical utility of screening asymptomatic transplant candidates remains unclear. A large degree of variation exists among both transplant center practice patterns and clinical practice guidelines regarding who should be screened, and opinions are based on mixed observational data with great potential for bias. In this review, we discuss the potential risks, benefits, and evidence for screening for CVD in kidney transplant candidates, and also the next steps to better evaluate and treat asymptomatic kidney transplant candidates.

Perioperative management of cardiac disease

Pre-existing cardiac disease contributes significantly to morbidity and mortality amongst patients undergoing non cardiac surgery. Patients with pre-existing cardiac disease or with risk factors for it, have as much as a 3.9% risk of suffering a major perioperative cardiac event (Lee et al 1999, Devereaux 2005). Furthermore, the incidence of perioperative myocardial infarction (MI) is increased 10 to 50 fold in patients with previous coronary events (Jassal 2008).

The aetiology of myocardial injury after non-cardiac surgery

Recognition of myocardial injury after non-cardiac surgery is difficult, since strong analgesics (e.g. opioids) can mask anginal symptoms, and ECG abnormalities are subtle or transient. Thorough knowledge of the pathophysiological mechanisms is therefore essential. These mechanisms can be subdivided into four groups: type I myocardial infraction (MI), type II MI, non-ischaemic cardiac pathology, and non-cardiac pathology. The incidence of type I MI in patients with a clinical suspicion of perioperative acute coronary syndrome (ACS) is 45-57 %. This percentage is higher in patients with a high likelihood of MI such as patients with ST-elevation ACS. Of note, the generalisability of this statement is limited due to significant study limitations. Non-ischaemic cardiac pathology and non-cardiac pathology should not be overlooked as a cause of perioperative myocardial injury (PMI). Especially pulmonary embolism and dysrhythmias are a common phenomenon, and may convey important prognostic value. Implementation of routine postoperative troponin assessment and accessible use of minimally invasive imaging should be considered to provide adequate individualised therapy. Also, addition of preoperative imaging may improve the stratification of high-risk patients who may benefit from preoperative or perioperative interventions.

Statin therapy in the reduction of cardiovascular events in patients undergoing intermediate-risk noncardiac, nonvascular surgery

BACKGROUND

Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) reduce perioperative cardiac events in high-risk patients undergoing cardiovascular surgery. However, there is paucity of data on the role of statins in patients undergoing intermediate-risk noncardiac, nonvascular surgery (NCNVS).

HYPOTHESIS

Statins are cardioprotective in intermediate-risk NCNVS.

METHODS

We identified a retrospective cohort of patients undergoing intermediate risk NCNVS. Our composite end point (CEP) included 30-day all-cause mortality, atrial fibrillation (AF), and nonfatal myocardial infarction (MI). A stepwise logistic regression with adjustment using propensity scores was performed to determine if statin therapy was independently associated with the risk reduction of adverse postoperative cardiovascular outcomes.

RESULTS

We identified 752 patients. Seventy-five of them (9.97%) developed composite end points; 10 (1.33%) had in-hospital nonfatal MI, 44 (5.85%) developed AF, and 35 (4.65%) died within 30 days. The 30-day all-cause mortality was 31/478 (6.48%) among statin nonusers vs 4/274 (1.45%) for statin users (P < 0.002). As compared with nonusers, patients on statin therapy had a 5-fold reduced risk of 30-day all-cause mortality. Statin therapy was associated with decreased CEP after adjusting for baseline characteristics, with a propensity score to predict use of statins (odds ratio [OR]: 0.54, 95% confidence interval [CI]: 0.30-0.97, P = 0.039). After further adjustment for propensity score, diabetes mellitus, percutaneous coronary intervention, and prior coronary artery bypass grafting, statin therapy proved beneficial (OR: 0.51, 95% CI: 0.28-0.92, P = 0.026).

CONCLUSIONS

Statin use in the perioperative period was associated with a reduction in cardiovascular adverse events and 30-day all-cause mortality in patients undergoing intermediate-risk NCNVS.

Angiographic and clinical characteristics of type 1 versus type 2 perioperative myocardial infarction

OBJECTIVES

The aim of this study was to analyze clinical and angiographic differences between the two etiologic subtypes of perioperative myocardial infarction (PMI).

BACKGROUND

PMI is believed to occur by either reduced coronary blood flow attributable to acute plaque rupture and thrombosis (type 1) or primary increase in oxygen demand in the setting of stable but stenotic lesions (type 2). Incidence and mortality rates of PMI are substantial, but angiographic and clinical features are not well characterized.

METHODS

Consecutive patients with PMI were classified as "type 1" or "type 2" based on angiographic characteristics of culprit lesions. Clinical and angiographic characteristics of each subtype were compared using statistical analyses.

RESULTS

Of the 54 patients analyzed, 32 (59%) cases had type 1 PMI, whereas 22 others (41%) had type 2 PMI. Compared with type 2 patients, those with type 1 PMI more often had ECG (electrocardiogram) ST elevation (53% versus 23%, P = 0.026), greater peak troponin (15.3 ng/dl versus 5.3 ng/dl, P = 0.035), higher preoperative mean blood pressure (103 mm Hg versus 93 mm Hg, P = 0.009), greater decrease in mean intraoperative blood pressure (-36 mm Hg versus -26 mm Hg, P = 0.015). Type I patients trended toward greater in-hospital mortality (16% versus 5%, P = 0.38) and length of hospitalization (13.5 days versus 9.0 days, P = 0.13).

CONCLUSIONS

These results demonstrate that PMI not only results from "demand ischemia" but also that in nearly 60% of cases the cause is acute plaque rupture. Patients with PMI attributable to plaque rupture suffer more intraoperative hypotension, greater transmural ischemia, larger infarct size, and trended toward worse outcome.

STAR VaS--Short Term Atorvastatin Regime for Vasculopathic Subjects: a randomized placebo-controlled trial evaluating perioperative atorvastatin therapy in noncardiac surgery

PURPOSE

Evidence suggests that statins reduce cardiovascular complications in patients undergoing noncardiac surgery, although questions remain regarding the mechanism of benefit and the preferred dosing strategy. In this trial, we evaluated the perioperative effects on C-reactive protein (CRP) that resulted from starting atorvastatin within seven days of noncardiac surgery. The objective was to identify anti-inflammatory effects of atorvastatin prior to conducting a large randomized trial with clinical end points.

METHODS

In a single centre, parallel group, placebo-controlled trial, sixty high cardiac risk participants over age 45 yr undergoing noncardiac surgery were assigned randomly to one of three groups to receive atorvastatin 80 mg (A) and/or placebo (P). Group AA (n = 26) received atorvastatin seven days before surgery, the day of surgery, and for seven days post surgery. Group PA (n = 17) received placebo seven days before surgery, atorvastatin on the day of surgery, and atorvastatin for seven days post surgery. Group PP (n = 17) received placebo at all times. All participants, health care professionals, research assistants, and outcome adjudicators were masked to treatment allocation. Analyses were by intention to treat. The primary outcome was the C-reactive protein level at 48 hr.

RESULTS

Fifty-six participants completed the 30-day follow-up. The mean (standard deviation) changes in CRP levels from baseline at 48 hr in Groups AA, PA, and PP were 141.0 (72.4), 153.5 (42.2), and 111.2 (84.6), respectively. The mean differences (95% confidence interval) at 48 hr for AA vs PA, AA vs PP, and PA vs PP were: -20.1 (-81.2 to 41.1), 22.7 (-31.7 to 77.2), and 42.8 (-20.0 to 105.7), respectively, adjusting for baseline CRP, type of procedure, presence of coronary artery disease, use of medications, and for multiple comparisons using Tukey's method.

CONCLUSIONS

Administration of atorvastatin, initiated within seven days preoperatively, was not associated with clinically significant reductions in CRP levels.

Preoperative cardiac evaluation of the vascular surgery patient--an anesthesia perspective

The morbidity and mortality associated with vascular surgery procedures are largely the results of cardiac events. National guidelines have been regularly proposed and updated by the American College of Cardiology (ACC)/American Heart Association (AHA) to ensure optimal perioperative management and risk stratification. Controversy remains between experts and other cardiology societies regarding several patient care issues including revascularization before surgery, timing of β-blocker therapy, and the administration of antiplatelet therapy. Several landmark articles recently published have helped to modify the guidelines in the hope of improving vascular patient outcomes. In this review, we searched all recent available literature pertaining to perioperative cardiac evaluation before major vascular surgery. We propose an algorithm for preoperative cardiac evaluation, which is a modification to the AHA recommendations. Incorporated in this algorithm are recent published pivotal articles that can help in guiding physicians caring for the vascular patient requiring major operative or endovascular interventions.

The evolving role of preoperative testing in vascular surgery patients: can a little knowledge be dangerous?

It has been traditionally recommended that candidates for vascular surgery receive noninvasive stress perfusion testing risk stratification to help decide which patients may benefit from coronary artery revascularization. Recent clinical trials have contested the efficacy of revascularization in this population as well as the information yield of noninvasive testing. This article reviews a number of these studies that are likely to change our beliefs regarding testing and subsequent interventions as well as evolving role of medical therapy in patients undergoing vascular surgery.

Culprit coronary lesions requiring percutaneous coronary intervention after vascular surgery often arise from in-stent restenosis of bare metal stents

BACKGROUND

The natural history of coronary artery disease (CAD) after vascular surgery is poorly defined. The aim of this study was to determine the temporal change of coronary artery lesions requiring revascularization with a percutaneous coronary intervention (PCI) after elective vascular surgery and to determine the utility of preoperative biomarkers on predicting those patients at risk for new coronary lesions.

METHODS

The Coronary Artery Revascularization Prophylaxis Trial tested the long-term survival benefit of coronary artery revascularization before elective vascular surgery. Among randomized patients who subsequently required PCI after surgery, the stenosis of the culprit lesion from the follow-up angiogram was compared with the preoperative vessel stenosis at the identical site on the baseline angiogram.

RESULTS

A total of 30 patients underwent PCI for progressive symptoms at a median of 11.5 (interquartiles: 4.5-18.5) months postsurgery. Of 30 patients, 16 (53%) had nonobstructive CAD preoperatively (group 1) with a stenosis that increased from 17 +/- 6% to 91 +/- 2% (P < 0.01) and 14 (47%) had severe CAD at the culprit site preoperatively (group 2), with a stenosis that increased 89 +/- 2% (P = 0.15). The only biomarker that was an identifier of early coronary artery lesion formation in group 1 compared with group 2 patients was a higher baseline homocysteine level (14.6 +/- 1.4 vs. 10.6 +/- 0.7 mg/dL; P = 0.02).

CONCLUSIONS

Culprit coronary artery lesions requiring PCI after an elective vascular operation often arise from in-stent restenosis. Therapies that either stabilize existing plaques or prevent restenosis, particularly among patients with elevated homocysteine levels, have the greatest promise for improving postoperative outcomes.

The pathophysiology of peri-operative myocardial infarction

SUMMARY

It is generally believed that plaque rupture and myocardial oxygen supply-demand imbalance contribute approximately equally to the burden of peri-operative myocardial infarction. This review critically analyses data of post-mortem, pre-operative coronary angiography, troponin surveillance, other pre-operative non-invasive investigations, and peri-operative haemodynamic predictors of myocardial ischaemia and/or myocardial infarction. The current evidence suggests that myocardial oxygen supply-demand imbalance predominates in the early postoperative period. It is likely that flow stagnation and thrombus formation is an important pathway in the development of a peri-operative myocardial infarction, in addition to the more commonly recognised role of peri-operative tachycardia. Research and therapeutic interventions should be focused on the prediction and therapy of flow stagnation and thrombus formation. Plaque rupture appears to be a more random event, distributed over the entire peri-operative admission.