Does preoperative coronary revascularization before noncardiac surgery reduce the risk of coronary events in patients with known coronary artery disease?

How to optimize patients for geriatric fracture surgery

Low-energy fragility fractures account for >80% of fractures in elderly patients, and with aging populations, geriatric fracture surgery makes up a substantial proportion of the orthopedic workload. Elderly patients have markedly less physiologic reserve than do younger patients, and comorbidity is common. Even with optimal care, the risk of mortality and morbidity remains high. Multidisciplinary care, including early orthogeriatric input, is recommended to anticipate and treat complications. This article explores modern treatment strategies for this challenging group of patients and provides guidance for systematically preparing and optimizing elderly patients before surgery, based on best available current evidence and recommendations by relevant health organizations.

Cardiac screening before noncardiac surgery

Cardiovascular complications are infrequent but can result in significant morbidity following noncardiac surgery, especially in patients with peripheral vascular disease or increased age. All patients require some level of preoperative screening to identify and minimize immediate and future risk, with a careful focus on known coronary artery disease or risks for coronary artery disease and functional capacity. The 2007 American College of Cardiology/American Heart Association Guidelines are clear that noninvasive and invasive testing should be limited to circumstances in which results will clearly affect patient management or in which testing would otherwise be indicated. beta-Blocker therapy has become controversial in light of recent publications but should be continued in patients already on therapy, and started in patients with high cardiac risk undergoing intermediate- or high-risk surgery.

Heparin-Coated Stents Do Not Protect Cancer Patients from Cardiac Complications after Noncardiac Surgery

Previous studies regarding preoperative coronary stents and antithrombotic agents have excluded patients with cancer as a result of hypercoagulability. The objective of this study is to determine whether preoperative heparin-coated coronary stents are as safe in patients with cancer undergoing surgery as patients without cancer. Between February 2003 and February 2005, 29 patients had heparin-coated coronary stents placed before noncardiac surgery. The incidence of postoperative myocardial infarction (MI) and/or death was compared in patients with and without cancer, and outcomes were further evaluated based on preoperative antithrombotic status. Postoperative MI occurred in three of 13 (23%) patients with cancer compared with zero of 16 non-cancer patients. Patients with cancer were 9.6 times more likely to have a postoperative MI resulting in death compared with noncancer patients. There was a positive correlation between patients having cancer and having a postoperative MI ( r = 0.38, P = 0.044) and between patients with cancer being on antithrombotic medications during surgery and having a postoperative MI ( r = 0.567, P = 0.044). After stent placement, patients with cancer undergoing surgery experienced a higher incidence of postoperative MI resulting in death compared with noncancer patients despite continued antithrombotic use. In these patients, alternatives to stenting should be considered to avoid perioperative cardiac complications.

The impact of a cardioprotective protocol on the incidence of cardiac complications after aortic abdominal surgery

We analyzed a local database including 468 consecutive patients who underwent elective aortic abdominal surgery over an 8-yr period in a single institution. A new cardioprotective perioperative protocol was introduced in January 1997, and we questioned whether perioperative cardiac outcome could be favorably influenced by the application of a stepwise cardiovascular evaluation based on the American College of Cardiology/American Heart Association guidelines and by the use of antiadrenergic drugs. Clonidine was administered during surgery, and beta-blockers were titrated after surgery to achieve heart rates less than 80 bpm. We compared data of two consecutive 4-yr periods (1993-1996 [control period] versus 1997-2000 [intervention period]). Implementation of American College of Cardiology/American Heart Association guidelines was associated with increased preoperative myocardial scanning (44.3% vs 20.6%; P < 0.05) and coronary revascularization (7.7% vs 0.8%; P < 0.05). During the intervention period, there was a significant decrease in the incidence of cardiac complications (from 11.3% to 4.5%) and an increase in event-free survival at 1 yr after surgery (from 91.3% to 98.2%). Multivariate regression analysis showed that the combined administration of clonidine and beta-blockers was associated with a decreased risk of cardiovascular events (odds ratio, 0.3; 95% confidence interval, 0.1-0.8), whereas major bleeding, renal insufficiency, and chronic obstructive pulmonary disease were predictive of cardiac complications. In conclusion, cardiac testing was helpful to identify a small subset of high-risk patients who might benefit from coronary revascularization. Sequential and selective antiadrenergic treatments were associated with improved postoperative cardiac outcome.

IMPLICATIONS

Implementation of American College of Cardiology/American Heart Association guidelines and use of antiadrenergic drugs were associated with better cardiac outcomes after major vascular surgery.

Assessment of cardiac risk before aortic reconstruction: noninvasive work-up using clinical examination, exercise testing, and dobutamine stress echocardiography versus routine coronary arteriography

In this prospective study we evaluated the efficacy of a battery of noninvasive tests including clinical evaluation (CE), exercise testing (ET), and dobutamine stress echocardiography (DSE) for assessment of cardiac risk in 90 patients indicated for aortic reconstruction. As the gold-standard reference technique, coronary arteriography was performed in each patient after noninvasive evaluation. The sensitivity of CE was low (61%). ET proved to be more sensitive (71.4%) and highly specific (95.8%) but feasibility (77%) and diagnostic accuracy (42%) were low. DSE demonstrated acceptable sensitivity (78%) and specificity (75.5%) with high feasibility (94.5%) and diagnostic accuracy (100%). None of the four patients with false negative ET results and only one of seven with false-negative DSE required coronary bypass. On the basis of these findings we conclude that a combination of CE and ET with DES, if necessary, can reliably assess cardiac risk before aortic reconstruction. Noninvasive assessment is a reliable alternative to routine coronary arteriography.

The role of myocardial revascularization preceding noncardiac surgery

Of about 6.7 million Americans who have coronary artery disease, approximately 700,000 undergo various noncardiac operations annually in the United States. Perioperative cardiac complications remain the leading cause of morbidity and mortality not related to the primary operative procedure; the mechanisms of perioperative ischemia and infarction are unclear. Currently, clinicians, using a combination of clinical and laboratory findings, can estimate the risk of noncardiac surgical procedures with a high degree of precision, but much less is known about the preferred approach to patient management after noninvasive risk stratification. Coronary angiography and revascularization are frequently recommended for those determined by functional tests to be at moderate and high risk, but the risks of revascularization are often substantially higher among these patients. No randomized, controlled trials exist to guide patient management. Quantitative decision analysis based on published nonrandomized data suggests that coronary angiography with selective myocardial revascularization should be performed to reduce the risk of noncardiac surgery only if the risk of noncardiac surgery is greater than 5% and the risk of coronary angiography with selective revascularization is less than 3%. On the other hand, if independent indications exist for myocardial revascularization, it should generally be performed before the noncardiac operation.

Expert opinion regarding indications for coronary angiography before noncardiac surgery

Whether to perform coronary angiography on the basis of preoperative noninvasive cardiac testing remains a difficult decision. We hypothesized that there are noninvasive test results for which experts have general agreement about the indication for preoperative coronary angiography. We asked 30 experts (24 in specific diagnostic tests and six in clinical cardiology) to comment on statements regarding hypothetical noninvasive test results. There was agreement that catheterization should be performed for (1) exercise electrocardiographic ischemia with a blood pressure drop > 10 mm Hg, (2) stress perfusion scan reversibility in one half or more of single-photon emission computed tomographic slices, and (3) stress echo ischemia in more than five segments, two or more coronary artery zones, or four left anterior descending coronary artery segments. Therefore coronary angiography should be performed for results of noninvasive tests that indicate large zones of myocardial ischemia and not for limited ischemia or test abnormalities without other significant findings.

[Role of noninvasive examinations in the management of ischemic cardiopathy. V. Noninvasive examinations in the management of patients with chronic ischemic cardiopathy]

In the last few years the has been an enormous development in noninvasive testing in the field of clinical cardiology. In fact, excellent monographs on each one of these techniques have been published elsewhere, but fewer publications exist that treat the topic of their indications and use in an integrated way, except for in the most common clinical situations. In this paper, the treatment of patients who present chest pain, stable and unstable angina is discussed, including the study of postinfarction patients. Furthermore, the role of noninvasive tests in the detection of coronary heart disease in women and in patients with left bundle branch block is thoroughly analyzed; as well as their usefulness after surgical or percutaneous coronary revascularization and in patients with peripheral vascular disease.

Cardiac complications in noncardiac surgery: value of dobutamine stress echocardiography versus dipyridamole thallium imaging

OBJECTIVES

The objective of this study was to determine the relative value of dobutamine stress echocardiography (DSE) and dipyridamole thallium imaging (DT) in the preoperative assessment of cardiovascular risk before noncardiac surgery.

DESIGN

Prospectively DSE was performed in patients who had undergone DT as a part of their preoperative evaluation.

SETTING

A large urban veterans' affairs medical center.

PARTICIPANTS

Thirty-seven patients undergoing major noncardiac surgery were assessed for complications during a 1-month follow-up period.

INTERVENTIONS

Both DSE and DT were performed before surgery. The medium interval between the two tests were 15.5 days.

MEASUREMENTS

Left ventricular wall motion was assessed at baseline and peak dobutamine dose in a standard fashion. Wall motion was scored and indexed using a 16-segment model. A positive DSE was defined as failure of augmentation, new or worsening of baseline wall motion abnormalities in two or more contiguous segments. Myocardial perfusion studies after DT were performed according to conventional method. A positive DT was defined as a reversible perfusion defect, increased lung uptake, and/or transient left ventricular dilatation. Complications were defined as myocardial infarction or cardiac death occurring as a result of the operation, or need for revascularization before surgery.

RESULTS

DSE was positive in 19 patients, whereas DT was positive in 25 patients. Fourteen patients had both an abnormal DSE and DT. Five patients had major postoperative cardiac complications: fetal myocardial infarction (1); fatal cardiac arrest (1); and severe coronary artery disease necessitating coronary artery bypass surgery (2) or percutaneous transluminal coronary angioplasty (1). DSE was positive in all 5 (100%), whereas DT was positive in 4 of 5 (80%) patients with complications. The sensitivity for each test was comparable: for DSE it was 100% (95% C.I. 56% to 100%) and for DT 80% (37% to 96%). Specificity for DSE (60%, 43%-74%) was somewhat higher than DT (38%, 24% to 54%), although this did not reach statistical significance (p = 0.06).

CONCLUSIONS

The ability of DSE to predict major cardiac complications related to noncardiac surgery appears to be similar to DT and may be used as an alternative to DT imaging in the preoperative risk assessment of patients undergoing noncardiac surgery.

Additive value of thallium single-photon emission computed tomography myocardial imaging for prediction of perioperative events in clinically selected high cardiac risk patients having abdominal aortic surgery

The present study was designed to prospectively evaluate whether reinjection thallium-201 single-photon emission computed tomography (SPECT) has a significant additive predictive value for occurrence of perioperative cardiac events in clinically selected patients at high cardiac risk undergoing abdominal aortic surgery. Of a group of 517 consecutive patients referred, 134 had > or = 2 of the following clinical or electrocardiographic cardiac risk variables: age > 70 years; history of myocardial infarction, angina, or congestive heart failure; diabetes mellitus; hypertension with severe left ventricular hypertrophy; and Q waves or ischemic ST-segment abnormalities on electrocardiogram at rest. Operation was performed after thallium SPECT study. Twelve patients (9%) had major perioperative events (cardiac death or nonfatal myocardial infarction) and 18 patients had other cardiac events (unstable angina, congestive heart failure, or severe ventricular tachyarrhythmia). Variables correlated with the occurrence of major events were history of myocardial infarction (p < 0.05) and the presence (p < 0.001) and number of segments with thallium reversible defects (p < 0.001). In multivariate analysis, history of myocardial infarction (p < 0.05) and the number of segments with reversible thallium defects (p < 0.001) were independent predictors. When all the cardiac events were taken into consideration, all the previous variables, as well as Q waves and ischemic ST abnormalities on the electrocardiogram, showed significant predictive value in both univariate and multivariate analyses. Furthermore, thallium SPECT imaging has an additive predictive value for major cardiac events over clinical and electrocardiographic risk factors. When performed on clinically selected patients at high cardiac risk undergoing abdominal aortic surgery, thallium SPECT demonstrates significant prognostic value for cardiac events over that provided by clinical variables alone.