Negative impact of cardiac evaluation before vascular surgery

Perioperative body weight change is associated with in-hospital mortality in cardiac surgical patients with postoperative acute kidney injury

Background

Postoperative acute kidney injury (AKI) is common following cardiac surgery (CS). Body weight (BW) may be an amenable variable by representing the summation of the nutritional and the fluid status. However, the predictive role of perioperative BW changes in CS patients with severe postoperative AKI is never explored. This study aimed to evaluate this association.

Methods

This study was conducted using a prospectively collected multicenter cohort, NSARF (National Taiwan University Hospital Study Group on Acute Renal Failure) database. The adult CS patients with postoperative AKI requiring renal replacement therapy (RRT), who had clear initial consciousness, received CS within 14 days of hospitalization, and underwent RRT within seven days after CS in intensive care units from January 2001 to January 2014 were enrolled. With the endpoint of 30-day postoperative mortality, we evaluated the association between the clinical factors denoting fluid status and patients outcomes.

Results

A total of 188 patients (70 female, mean age 63.7 ± 15.2 years) were enrolled. Comparing with the survivors (n = 124), the non-survivors (n = 64) had a significantly higher perioperative BW change [3.6 ± 6.1% versus 0.1 ± 8.3%, p = 0.003] but not the postoperative and pre-RRT BW changes. By using multivariate Cox proportional hazards model, the independent indicators of 30-day postoperative mortality included perioperative BW change (p = 0.026) and packed red blood cells transfusion (p = 0.007), postoperative intra-aortic balloon pump (p = 0.001) and central venous pressure level (p = 0.005), as well as heart rate (p = 0.022), sequential organ failure assessment score (p < 0.001), logistic organ dysfunction score (p = 0.001), and blood total bilirubin level (p = 0.044) at RRT initiation. The generalized additive models further demonstrated, in a multivariate manner, that the mortality risk rose significantly during a perioperative BW change of 2% to 15%.

Conclusions

Perioperative BW change was independently associated with an increased risk for 30-day postoperative mortality in CS patients with RRT-requiring AKI.

American College of Cardiology/American Heart Association perioperative assessment guidelines for noncardiac surgery reduces cardiologic resource utilization preserving a favourable clinical outcome

OBJECTIVES

The American College of Cardiology (ACC) and the American Heart Association (AHA) provided perioperative evaluation and management guidelines for assessing cardiac risk in noncardiac surgery. Even if previously validated as safe and effective in risk stratification, there is often a gap between clinical practice and the recommendations of the ACC/AHA guidelines. We evaluated the impact of strict application of ACC/AHA guidelines for cardiac risk assessment of patients undergoing elective noncardiac vascular surgery in a consultant anaesthesiologist-led preoperative clinic.

METHODS

One hundred and sixty-four consecutive patients who underwent elective vascular surgery after ACC/AHA guidelines implementation (from September 2004 to May 2005) were enrolled in the study and compared with a historical group of 166 patients operated from April 2002 to September 2002. Preoperative resources utilization (cardiologic consultations, non-invasive diagnostic tests, coronary angiograms, coronary revascularizations) and clinical events [all-cause death, acute myocardial infarction (AMI) and acute myocardial ischaemia] occurring within 30 days after surgical procedure were compared.

RESULTS

Guidelines implementation reduced preoperative cardiologic consultations by 21% (P < 0.001) and preoperative non-invasive diagnostic testing by 11% (P = 0.01), and increased utilization of preoperative beta-blockers by 13% (P = 0.01). Preoperative coronary angiograms (2% versus 4%) and coronary revascularizations (3% versus 2%) and all-cause death (1% versus 2%), AMI (2% versus 1%) and acute myocardial ischaemia (4% versus 2%) during follow-up were similar in both groups.

CONCLUSIONS

Implementation of the ACC/AHA guidelines for cardiac risk assessment prior to noncardiac surgery in a consultant anaesthesiologist-led preoperative clinic reduced preoperative resources utilization, improved medical treatment and preserved a low rate of perioperative cardiac complications.

Economic aspects of an anesthesia preoperative evaluation clinic

Studies continue to demonstrate that preoperative evaluation clinics help to prepare patients for surgery in a manner that minimizes cost and optimizes outcomes. These clinics are becoming common in both teaching and community hospitals. Many full service preoperative assessment clinics utilize specially trained nurses who are under the direction of an anesthesiologist. These clinics are associated with favorable outcomes, dramatic decreases in preoperative testing, infrequent subspecialty consultation and shorter lengths of stay. The current literature is reviewed and organizational and clinical changes that improve efficiency and patient care are highlighted.

Myocardial infarction in major noncardiac surgery: Epidemiology, pathophysiology and prevention

The number of subjects undergoing major noncardiac surgery who are at risk for perioperative myocardial infarction (MI) is growing worldwide.

It has been estimated that 500,000 to 900,000 patients suffer major perioperative cardiovascular complications every year, with consequent heavy, long-term prognostic implications and costs.

It is well known that perioperative MIs don’t share the same pathophysiology as nonsurgical MIs but the relative role of the different, potential triggers has not been completely clarified.

Many aspects of the perioperative management, including risk-stratification and prophylactic or postoperative interventions have also not been completely defined.

Throughout recent years many resources have been invested to clarify these aspects and experts have developed indices and algorithm-based strategies to better assess the cardiac risk and to guide the perioperative management.

The scope of the present review is to discuss the main aspects of perioperative MI in noncardiac surgery, with particular regard to epidemiology, pathophysiology, preoperative risk stratification, prophylaxis and therapy.

Preoperative cardiac evaluation does not improve or predict perioperative or late survival in asymptomatic diabetic patients undergoing elective infrainguinal arterial reconstruction

OBJECTIVE

Patients undergoing infrainguinal arterial reconstruction frequently have increased cardiac risk factors. Diabetic patients are often asymptomatic despite advanced cardiac disease. This study investigates whether preoperative cardiac testing improves the outcome in diabetic patients at risk for cardiac disease.

METHODS

We retrospectively reviewed all patients undergoing lower-extremity arterial reconstructions in a 32-month period from July 1999 to February 2002. Of the 433 patients identified undergoing 539 procedures, 295 had diabetes mellitus and considered in this study. The patients were stratified into two groups according to the present American College of Cardiology, American Heart Association (ACC/AHA) algorithm. We identified 140 patients with two or more of ACC (Eagle) criteria who met the inclusion criteria for a preoperative cardiac evaluation. These patients were separated into two groups: those undergoing a cardiac work-up (WU) according to the ACC/AHA algorithm and those not undergoing the recommended work-up (NWU). Outcomes included perioperative mortality, postoperative myocardial infarction, congestive heart failure, arrhythmia, and length of hospitalization. Significance of association was assessed by the Fisher exact test. Length of hospitalization was compared using the Kruskal-Wallis rank sum test. Survival data was analyzed with the Kaplan-Meier method.

RESULTS

One hundred forty patients met the criteria for moderate risk. There were 61 patients in the NWU group and 79 in the WU group. Ten patients in the WU group underwent preoperative coronary revascularization (6 had percutaneous transluminal coronary angioplasty, 4 underwent coronary artery bypass grafting). There was no difference between perioperative mortality (WU, 1%; NWU, 2%; P = 1.00) or in postoperative cardiac morbidity, including myocardial infarction, congestive heart failure, and arrhythmia requiring treatment (WU, 5%; NWU, 6%; P = .71). There were no perioperative deaths and one episode of congestive heart failure in the group that had preoperative coronary revascularization. Median length of hospitalization was 10 days in the WU group and 8 days in the NWU group ( P = .11). Patient survival at 12 months for the NWU, WU, and revascularized groups was 85.3%, 78.5%, and 80.0%, respectively; 36-month survival was 73.6%, 62.9%, and 80.0%, respectively. The three survival curves did not differ significantly ( P = .209).

CONCLUSIONS

Preoperative cardiac evaluation, as defined by the ACC/AHA algorithm, does not predict or improve postoperative morbidity, mortality, or 36-month survival in asymptomatic, diabetic patients undergoing elective lower-extremity arterial reconstruction. These data do not support the current ACC/AHA recommendations as a standard of care for diabetic patients with an intermediate clinical predictor who undergo peripheral arterial reconstruction, a high-risk surgical procedure.

Very late survival after vascular surgery

PURPOSE

The aim of this study was to define very late survival in veterans who routinely underwent preoperative assessment of left ventricular function using radionuclide ventriculography (RNVG) before elective major vascular surgery from 7/84 to 7/88 at one Veterans Affairs Medical Center.

METHODS

RNVG defined left ventricular ejection fraction (EF) and determined the presence of ventricular wall motion abnormalities. Patients undergoing elective vascular surgery (n = 310) who had preoperative RNVG were then followed over the years using direct contact, VA administrative databases, and, most recently, the Social Security Death Index.

RESULTS

Follow-up was 6.64 +/- 4.62 years (range 0 to 16.2 years). Current survival is 10% (11/107) after carotid surgery, 12% (10/82) after aortic aneurysm repair, 15% (17/111) after extremity reconstruction, and 0% (0/10) after visceral artery reconstruction (ns). There was no statistically significant difference in mortality between the different types of vascular surgery at 30 days or at 1, 5, and 10 years after surgery (ns). Actual survival rates at 5 years after carotid surgery, aneurysm repair, extremity reconstruction, and visceral reconstruction were 55, 61, 59, and 50%, respectively. Stepwise logistic regression analysis was performed which included preoperatively defined cardiovascular risk factors, type of surgery, and results of RNVG. The final regression model indicated that age, diabetes, smoking at the time of surgery, and low EF were independently associated with overall mortality while angina, prior myocardial infarction (MI), and type of operation were not. Mean survival duration with normal EF (>50%) was 7.99 years versus 4.78 years with low EF (P < 0.001). No patient with severe left ventricular dysfunction (EF < or = 35%; n = 39) or who had postoperative cardiac complications (MI, CHF, ventricular arrhythmia; n = 38) survived to the present.

CONCLUSIONS

Very late survival after major vascular surgery was related to the presence of diabetes, active smoking at the time of surgery, left ventricular function, and postoperative cardiac complications. Since there was no association of overall mortality with angina or prior MI, an aggressive approach to coronary evaluation in such patients might not alter very late survival.

Prediction of cardiac risk before abdominal aortic reconstruction: comparison of a revised Goldman Cardiac Risk Index and radioisotope ejection fraction

BACKGROUND

A revised Goldman Cardiac Risk Index has been suggested to identify patients at higher risk for cardiac complications in patients who undergo major noncardiac surgery. The aim of this study was to test the usefulness of this model in an independent series of patients who underwent abdominal aortic surgery and to compare the index with the multiple gated acquisition (MUGA) scan in the prediction of cardiac complications.

METHODS

We studied 77 patients who underwent MUGA scan before elective abdominal aortic reconstruction. The revised index was calculated for each patient after recording the following five risk factors: history of ischemic heart disease, congestive heart failure, cerebrovascular disease, insulin-dependent diabetes, and creatinine level more than 2 mg/dL. Technetium-99m MUGA scan provided information about the resting left ventricular ejection fraction (LVEF) and the presence of regional wall motion abnormalities.

RESULTS

Fourteen patients (18%) had cardiac complications develop. The index proved to be a satisfactory predictor of postoperative cardiac events (P =.008), and an abnormal LVEF failed to do so (P =.1). The presence of wall abnormalities, with or without an abnormal LVEF, predicted cardiac complications (P =.004 and P =.006). Patients with a higher index score showed a tendency to have a lower LVEF (Spearman rank correlation, r = -0.43; P <.001). Wall abnormalities, with or without an abnormal LVEF, were more frequent in patients with higher scores (P =.03 and P =.009). Combining the index with the LVEF or the wall abnormalities or both could further stratify the cardiac risk (P =.004, P =.0003 and P =.0006, with chi(2) test for trend).

CONCLUSION

For those patients who undergo elective abdominal aortic surgery, the revised Goldman Cardiac Risk Index is a simple method of evaluating cardiac risk with minimum resource implications. MUGA scan can offer additional stratification in patients judged with the index to be at high risk.

Anaesthesia and endovascular surgery

Anaesthetic requirements for endovascular surgery for aortic, carotid and peripheral vascular disease are reviewed. Peculiarities of the surgery which may impinge on anaesthetic management are discussed together with the pre-operative assessment issues of particular relevance to patients with generalized vascular disease. The detailed anaesthetic management for carotid and aortic endovascular repair is addressed. The lowered peri-operative stress and general morbidity levels which occur with endovascular surgery allow sicker patients with greater risk factors to present for this type of surgery, thus increasing the challenges facing anaesthetists.

Preoperative Evaluation of the Patient for Vascular Surgery in the "Real World"

Patients presenting for vascular surgery frequently have multiple coexisting diseases. To meet the goal of providing a safe anesthetic with optimum resource use, we must ex amine the impact of each of these conditions on the patient and how the data from a particular evaluation or test will impact our anesthetic plan. Existing guidelines may be valu able if adapted to institution-specific circumstances. Con sultants represent a relatively high-cost resource, which can be optimized when used with clear goals in sight. Finally, we may be able to modify our evaluation based on the antici pated procedure, as these patients are exposed to a range of potential hemodynamic stresses.