Dobutamine stress echocardiography for assessment of cardiac risk before noncardiac surgery

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Preoperative Dobutamine Stress Echocardiography and Clinical Factors for Assessment of Cardiac Risk after Noncardiac Surgery

BACKGROUND

The role of dobutamine stress echocardiography (DSE) in the risk stratification of patients undergoing noncardiac surgery in the current era is unclear. The aim of this study was to evaluate the yield of DSE and the additive role of DSE to clinical criteria for preoperative risk stratification of patients undergoing noncardiac surgery.

METHODS

The study included 4,494 patients undergoing DSE ≤90 days before noncardiac surgery. The primary outcome was a composite of postoperative myocardial infarction, cardiac arrest, and all-cause mortality ≤30 days after noncardiac surgery.

RESULTS

The overall 30-day postoperative cardiac event rate was 2.3%. The mortality rate was 0.9% overall and 0.7% and 1.3% after normal and abnormal results on DSE, respectively. Among clinical variables, the modified Revised Cardiac Risk Index score demonstrated the strongest association with postoperative risk (P < .001). Patients with Revised Cardiac Risk Index scores of ≥3 had an event rate of 7.5%. The event rates for patients with wall motion score index ≥1.7 at baseline, left ventricular ejection fractions <40% at peak stress, or ischemic thresholds <70% of age-predicted maximal heart rate were 7.1%, 8.6%, and 7.9%, respectively. After adjusting for clinical variables, the overall result of DSE (P < .001), baseline and peak-stress wall motion score index (P < .001 and P = .014, respectively), peak-stress left ventricular ejection fraction (P < .001), and the number of ischemic segments (P = .027) were all associated with postoperative cardiac events. Incremental multivariate analysis demonstrated that an overall abnormal result on DSE, added to clinical variables, was associated with an increased risk for postoperative cardiac events (odds ratio, 2.07; 95% CI, 1.35-3.17; P < .001).

CONCLUSIONS

Baseline and peak-stress findings on preoperative DSE add to the prognostic utility of clinical variables for stratifying cardiac risk after noncardiac surgery.

[The Clinical use of Stress Echocardiography in Ischemic Heart Disease Cardiovascular Ultrasound (2017)15:7. Translation authors: Arystan A.Zh., Fettser D.V.]

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows detecting myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependence on operator expertise, the lack of outcome data (a widespread problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

Practical guidance for the implementation of stress echocardiography

Exercise stress testing has been widely undertaken for the diagnosis of heart diseases. The accurate assessment of clinical conditions can be conducted by comparing the findings obtained from the results of stress echocardiography with the changes in the blood/heart rate and electrocardiograms. Numerous overseas studies have reported the utility of stress echocardiography in diagnosing myocardial ischemia; in Japan, the use of this modality for this purpose was included in the national health insurance reimbursable list in 2012. Nevertheless, stress echocardiography is far from being a widespread practice in Japan. This might be due to insufficient equipment (e.g., ergometers, space for test implementation) at each medical institution, shortage of technicians and sonographers who are well experienced and who are responsible for obtaining images during stress testing. The other possible reasons include the limited evidence available in Japan and the lack of a standardized testing protocol. Further dissemination of the practice of exercise stress echocardiography in this country is deemed necessary to establish satisfactory evidence for the use of stress echocardiography in the Japanese population. To this end, efforts are underway to develop a standardized protocol and report format to be adopted throughout Japan. We here present a guideline created by the Guideline Development Committee of the Japanese Society of Echocardiography that describes safe and effective stress echocardiography protocols and report formats. The readers are encouraged to perform exercise stress echocardiography using the proposed template for consensus document and report attached to this guideline.

The clinical use of stress echocardiography in ischemic heart disease

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows to detect myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician.

The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependance on operator expertise, the lack of outcome data (a widesperad problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

Potential role of coronary computed tomography angiogram in cardiac preoperative evaluation

Preoperative assessment of the cardiac patients before noncardiac surgery is concern in the clinical practice of anesthesiologist, surgeon, and medical consultant. The preferred stress testing is exercise electrocardiogram (ECG) in patients who are able to exercise and have normal ECG; however, either stress myocardial perfusion scintigraphy (MPS) or stress echocardiography is necessary if further testing is appropriately indicated before surgery. Unfortunately, stress MPs or stress echocardiography is not widely available and has some limitations. Coronary computed tomography angiogram (CCTA) has demonstrated excellent diagnostic accuracy in detecting coronary artery disease and accurate left ventricle function measurement. CCTA seems to be feasible, reliable, and has strong potential of becoming sole screening test before surgery.

Usefulness of an accelerated transoesophageal stress echocardiography in the preoperative evaluation of high risk severely obese subjects awaiting bariatric surgery

Background

Severe obesity is associated with an increased risk of coronary artery disease (CAD). Bariatric surgery is an effective procedure for long term weight management as well as reduction of comorbidities. Preoperative evaluation of cardiac operative risk may often be necessary but unfortunately standard imaging techniques are often suboptimal in these subjects. The purpose of this study was to demonstrate the feasibility, safety and utility of transesophageal dobutamine stress echocardiography (TE-DSE) using an adapted accelerated dobutamine infusion protocol in severely obese subjects with comorbidities being evaluated for bariatric surgery for assessing the presence of myocardial ischemia.

Methods

Subjects with severe obesity [body mass index (BMI) >40 kg/m²] with known or suspected CAD and being evaluated for bariatric surgery were recruited.

Results

Twenty subjects (9M/11F), aged 50 ± 8 years (mean ± SD), weighing 141 ± 21 kg and with a BMI of 50 ± 5 kg/m² were enrolled in the study and underwent a TE-DSE. The accelerated dobutamine infusion protocol used was well tolerated. Eighteen (90%) subjects reached their target heart rate with a mean intubation time of 13 ± 4 minutes. Mean dobutamine dose was 31.5 ± 9.9 ug/kg/min while mean atropine dose was 0.5 ± 0.3 mg. TE-DSE was well tolerated by all subjects without complications including no significant arrhythmia, hypotension or reduction in blood arterial saturation. Two subjects had abnormal TE-DSE suggestive of myocardial ischemia. All patients underwent bariatric surgery with no documented cardiovascular complications.

Conclusions

TE-DSE using an accelerated infusion protocol is a safe and well tolerated imaging technique for the evaluation of suspected myocardial ischemia and cardiac operative risk in severely obese patients awaiting bariatric surgery. Moreover, the absence of myocardial ischemia on TE-DSE correlates well with a low operative risk of cardiac event.

Recent advances in dobutamine stress echocardiography

Dobutamine stress echocardiography (DSE) is a reliable cardiac risk stratifier that has widespread applicability because of its clinical accuracy and cost effectiveness. Dobutamine has positive inotropic and chronotropic effects and is commonly used in patients who cannot exercise or achieve an adequate heart rate response with exercise. Recently available long-term results from several independent clinical trials, combined with enhancements in image quality, have improved the ability to detect significant coronary artery disease and determine myocardial viability. Dobutamine stress echocardiography has an excellent safety profile with clinical results superior to regular exercise electrocardiography and comparable with exercise echocardiography and radionucleotide perfusion stress imaging. Low-dose dobutamine response can accurately predict dysfunctional yet viable myocardial regions that may improve with revascularization. Clinical studies are now available refining the common use of DSE preoperatively in female patients with valvular disease, as well as in the emergency department. Dobutamine stress echocardiography does have some limitations in discriminating particular regions of ischemia when multiple ventricular segments are involved and when the imaging is suboptimal. It can be applied using minimal additional resources in an otherwise functioning echocardiography laboratory and, with appropriate training, can result in clinical results comparable with those of large-scale multicenter trials. Ongoing improvements in technology and the development of new reagents such as myocardial contrast agents hold promise for further advancement in the near future.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

Prognostic value of ankle-brachial index and dobutamine stress echocardiography for cardiovascular morbidity and all-cause mortality in patients with peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) is associated with an excessive risk for cardiovascular events and mortality. To determine measures prognostic of adverse events, ankle-brachial index (ABI) was compared with dobutamine stress echocardiography (DSE) in patients referred to our vascular center for the evaluation of PAD.

METHODS

The medical records of consecutive patients referred for the concurrent evaluation of PAD and coronary artery disease (CAD) between 1992 and 1995 were reviewed for subsequent cardiovascular events and death.

RESULTS

Among 395 patients (mean age, 69.7 +/- 9.6 years; 40% women), 341 had abnormal ABI and 268 had abnormal DSE (95 fixed and 173 stress-induced wall motion abnormalities). During a mean follow-up of 4.7 years, 27.3% of patients experienced a cardiovascular event, and 39.4% died. By multivariate analysis, ABI provided the strongest prediction of all-cause mortality (hazard ratio [HR], 2.34; 95% confidence interval [CI], 1.36 to 4.05; P = .002). Conversely, DSE with inducible or fixed wall motion abnormalities showed no association with cardiovascular events or increased mortality in multivariate analysis. The only DSE variable independently predictive of mortality was decreased left ventricular ejection fraction (<50%) at peak stress (HR, 1.70; 95% CI, 1.22 to 2.36; P = .002). Statin and aspirin therapy, but not beta-blockers, were protective. There was no relation between ABI and wall motion index score at rest or after stress.

CONCLUSIONS

In high-risk patients referred to our vascular center for the evaluation of PAD, the assessment of ABI provided a strong independent prediction of all-cause mortality. Therefore, proper interpretation of this simple, affordable, and reproducible measure extends beyond the assessment of PAD severity. Although a poor left ventricular response to dobutamine was also predictive, other echo variables were not.

ACC/AHA guidelines for preoperative cardiovascular evaluation for noncardiac surgery: a critical point of view

This review examines the issue of preoperative cardiac evaluation from a critical point of view, based on recent medical literature. We reviewed the history of that field and focused on the American College of Cardiology and American Heart Association guidelines, which are a cornerstone in the field of cardiac patients undergoing noncardiac surgery. These guidelines synthesized the data into a comprehensive format and established the concept of integrating the patient's risk with the surgical risk. Nevertheless, there are some weaknesses in the guidelines. We believe that a better understanding of the guideline limitations will allow an improved and more educated practice of its recommendations.

A Meta-Analytic Comparison of Preoperative Stress Echocardiography and Nuclear Scintigraphy Imaging

In this meta-analysis we compared thallium imaging (TI) and stress echocardiography (SE) in patients at risk for myocardial infarction (MI) scheduled for elective noncardiac surgery. Two searches of published articles were used to identify relevant articles. We included all studies that stated the criteria for a positive test and detailed the frequency of postoperative MI and in-hospital death. Data were abstracted by two authors and captured preoperative patient characteristics, study design, blinding, and outcome adjudication. We defined a positive test as a test with a reversible defect and, where possible, quantified the size of the defects in each study. MI and/or death were the only postoperative outcomes of interest. We calculated the sensitivity, specificity, and likelihood ratio (LR) and, where possible, the Receiver Operating Characteristic (ROC) curve of a cardiac event in each study. The LR and ROC were combined by meta-analyses using the random effects model. Heterogeneity was assessed using the I2 test. The search revealed 68 studies of 10,049 patients. There were 25 SE studies and 50 TI studies. There were 7 studies with a direct comparison of the two methodologies. The quality of studies differed; routine screening for MI was used more frequently in SE studies (47.8% versus 21.2%; P = 0.008) and screening dictated treatment more often after TI (72.1%) than after SE (46.3%) (P = 0.027). The LR for SE was more indicative of a postoperative cardiac event than TI (LR, 4.09; 95% CI, 3.21-6.56 versus 1.83; 1.59-2.10; P = 0.001). This difference was attributable to fewer false-negative SEs. There was no difference in the cumulative ROC curves from qualitative studies (SE, 0.80; 95% CI, 0.76-.84 versus TI, 0.75; 95% CI, 0.70-081). Again, the LR for a negative SE was less (0.23; 95% CI, 0.17-0.32 versus 0.44; 95% CI, 0.36-0.54). A moderate-to-large defect, seen in 14% of patients, by either method predicts a postoperative cardiac event (LR, 8.35; 95% CI, 5.6-12.45). This meta-analysis possesses the statistical power to demonstrate that SE has better negative predicative characteristics than TI. A moderate-to-large perfusion defect by either SE or TI predicts postoperative MI and death. We conclude the SE is superior to TI in predicting postoperative cardiac events.

The use of stress echocardiography for prognostication in coronary artery disease: an overview

PURPOSE OF REVIEW

Stress echocardiography has a high accuracy for the detection of coronary artery disease. Additionally, it provides clinically useful prognostic information, such as resting left ventricular function, myocardial viability, stress-induced ischemia, vascular extent of wall motion abnormalities, and changes in end-systolic volume and ejection fraction with stress.

RECENT DEVELOPMENTS

The timing, extent, and severity of the stress-induced wall motion abnormalities are important determinants of long-term prognosis. Previous studies have shown the efficacy of stress echocardiography in predicting long-term cardiac events in mixed patient groups and the value of this test in selected patient subsets.

SUMMARY

This review attempts to define the role of stress echocardiography for prognostication in coronary artery disease, pointing out the ability of this technique to identify low-risk and high-risk subsets among patients with known or suspected coronary artery disease and thus guide patient management decisions.

Preoperative cardiac evaluation

Guidelines on perioperative cardiovascular evaluation for noncardiac surgery have been published. The integration of clinical risk factors, surgery-specific risk,and functional capacity should be used to determine the need for further diagnostic evaluation. The use of beta-adrenergic blockade in high-risk patients,particularly those with documented myocardium at risk undergoing vascular surgery, has been shown to reduce perioperative risk and may obviate the need for more invasive procedures. Coronary intervention should be reserved for those patients who warrant intervention independent of the noncardiac surgery.

Safety of dobutamine stress echocardiography in patients with unruptured intracranial aneurysms

Dobutamine stress echocardiography has been increasingly used for the preoperative assessment of patients who undergo major vascular surgery. The safety of this modality has been well documented in various patient subgroups, including patients with aneurysms of the aorta. No previous reports, however, have addressed the safety of this form of stress testing in patients with unruptured intracranial aneurysms. After reviewing the experience of 2 institutions, we identified 40 patients who underwent dobutamine stress echocardiography while harboring at least 1 unruptured intracranial aneurysm, and found no evidence of aneurysm instability in relation to the dobutamine infusion. Although vasodilator stress modalities should intuitively be the non-exercise stress technique of choice in these patients, stress echocardiography with the use of dobutamine appears to be safe and represents an acceptable option when used for diagnostic purposes or preoperative risk stratification in this patient population.

Short- and long-term prognostic value of cardiac troponin I and dobutamine echocardiography in patients with stabilized acute coronary syndromes

BACKGROUND

This study investigated the short- and long-term prognostic values of cardiac troponin I (cTnI) and dobutamine echocardiography (DE) in patients with acute coronary syndrome (ACS) who stabilized after medical treatment.

METHODS AND RESULTS

171 consecutive patients of ACS accepted blood sampling for cTnI at the emergency department and DE at 4.9+/-0.6 days after admission. The prognostic values of cTnI, DE, and combined cTnI and DE were separately investigated at follow up periods of 30 days, 1 year and 3 years for hard events (cardiac death and non-fatal myocardial infarction) and all spontaneous events. CTnI was elevated in 55 (32%) patients and DE was positive in 114 (67%) patients. Elevated cTnI with positive DE were found in 44 (26%) patients. Within 30 days, the combination of elevated cTnI and positive DE provided more accurate prognostic information than each test result alone, and was the only independent predictor for both hard (p=0.014) and all events (p=0.012). After 1 year, cTnI alone had no prognostic value. The combination of an elevated cTnI level and a positive DE only had a prognostic value for all events (p=0.015). However, DE was an independent predictor for both hard (p=0.006) and all events (p=0.002). Neither cTnI alone nor cTnI combined with DE had a significant 3-year prognostic value. However, DE maintained its prognostic value and was still an independent predictor after 3 years for both hard (p=0.024) and all events (p=0.004).

CONCLUSIONS

For patients with stabilized ACS, the diagnostic finding of elevated cTnI combined with a positive DE has a better short-term prognostic value than each test alone. However, DE alone has a better long-term prognostic value.

Cardiac risk assessment for noncardiac surgery: current concepts

Strategies for perioperative risk assessment in patients undergoing noncardiac surgery vary among physicians and are aimed to estimate the risk and minimize complications. We propose simplistic guidelines for assessing and modifying risk for patients undergoing a wide variety of procedures.

Cardiac risk stratification of patients with symptomatic spinal stenosis

The leading cause of death in the perioperative period after noncardiac surgery is a cardiac event. As the number of lumbar surgeries performed in patients older than 65 years of age continues to increase, this patient population with neurogenic claudications is an at risk group for a cardiac event because of their age and associated cardiac risk factors. The authors attempted to document by means of cardiac chemical stress testing, the prevalence of silent ischemic cardiac disease in patients with neurogenic claudication who were candidates for elective lumbar surgery. Eleven of 140 patients (8%) had induced cardiac wall abnormalities on stress testing, indicating myocardial ischemia. The only risk factors associated with cardiac ischemia were smoking and history of heart disease. It is recommended that dobutamine stress echocardiography be performed in patients undergoing elective spinal surgery for symptomatic spinal stenosis if they have a history of previous heart disease, smoking, or both.

Diagnostic and prognostic use of stress echocardiography in stable patients

Stress echocardiography is an effective diagnostic and prognostic technique in stable patients with known or suspected coronary artery disease (CAD), myocardial infarction, or chronic left ventricular dysfunction and those undergoing noncardiac surgery. Stress echocardiography is sensitive and specific for the detection and extent of CAD. Negative tests confer a high negative predictive value for cardiac events regardless of the clinical risk. Positive studies confer a high positive predictive value for ischemic events in patients with intermediate to high clinical risk. Stress echocardiography provides incremental prognostic information relative to clinical, resting echocardiographic, and angiographic data. Meta-analysis studies have shown that the diagnostic and prognostic information provided by stress echocardiography is comparable to that from radionuclide scintigraphic stress tests. Stress echocardiography may be more specific for the detection and extent of CAD, whereas radionuclide scintigraphy may be more sensitive for one-vessel disease. Sensitivities are similar for the detection and extent of disease in patients with multivessel CAD.

Guidelines for perioperative cardiac evaluation from the American College of Cardiology/American Heart Association task force are effective for stratifying cardiac risk before aortic surgery

PURPOSE

We assessed whether the American College of Cardiology/American Heart Association (ACC/AHA) task force guidelines for perioperative cardiac evaluation could reliably stratify cardiac risk before aortic surgery.

METHODS

We retrospectively applied the guidelines to a closed database, set up prospectively. The setting was a referral center in an institutional practice with hospitalized patients. The closed database included 133 patients who had a routine cardiac examination, which comprised an estimation of functional capacity and noninvasive testing, before aortic surgery. This cardiac evaluation led to the proposal of coronarography in 23 patients and to treating an underlying coronary artery disease in 21 patients (including three myocardial revascularizations). One patient died after myocardial revascularization, and two patients died of cardiac causes after aortic surgery. The algorithm of the ACC/AHA guidelines was applied independently by two investigators to each patient's file that was included in the existing database. The main outcome measure was a comparison between cardiac risk stratification with the ACC/AHA guidelines and the results of the routine cardiac evaluation.

RESULTS

The ACC/AHA guidelines were successfully applied to all 133 files by the two investigators. After applying the algorithm, 73 patients were stratified as low cardiac risk, and 60 patients were stratified as high risk. The 21 patients who had undergone a preoperative coronary artery disease optimization were stratified as high risk by means of the ACC/AHA guidelines. The patients who died from cardiac causes were stratified as high risk by means of the ACC/AHA guidelines, whereas none of the patients stratified as low risk died during hospitalization.

CONCLUSION

The ACC/AHA guidelines were effective in stratifying cardiac risk by using clinical predictors and an estimate of the physical capacity of the patient. Their use may allow a reduction in unnecessary noninvasive testing in patients stratified as being at low risk, while permitting the selection of all patients likely to benefit from preoperative coronary artery disease optimization.

Assessment of cardiac risk before nonvascular surgery: dobutamine stress echocardiography in 530 patients

OBJECTIVE

This study evaluated the incremental value of dobutamine stress echocardiography (DSE) for assessment of cardiac risk before nonvascular surgery.

BACKGROUND

Limited information exists regarding the preoperative assessment of cardiac risk in patients with known or suspected coronary artery disease who are to undergo nonvascular surgery.

METHODS

All patients (303 men, 227 women) who underwent DSE before nonvascular surgery and did not sustain an intervening event (coronary revascularization or cardiac event) were studied. Clinical, electrocardiographic and rest and stress echocardiographic variables were evaluated to identify predictors of postoperative cardiac events.

RESULTS

Events occurred in 6% of patients: 1 cardiac death and 31 nonfatal myocardial infarctions. All of these patients had inducible ischemia on DSE (sensitivity 100%, specificity 63%). Multivariate predictors of postoperative events in patients with ischemia were history of congestive heart failure (p = 0.006; odds ratio = 4.66; confidence interval 1.55 to 14.02) and ischemic threshold less than 60% of age-predicted maximal heart rate (p = 0.0001; odds ratio 7.002; confidence interval 2.79 to 17.61). Clinical variables of Eagle's index identified 21% of patients as low, 68% as intermediate and 11% as high risk preoperatively; the postoperative event rates were 3%, 6%, and 14%, respectively. Dobutamine stress echocardiography identified 60% of patients as low (no ischemia), 32% as intermediate (ischemic threshold 60% or more) and 8% as high risk (ischemic threshold < 60%); postoperative event rates were 0%, 9% and 43%, respectively.

CONCLUSIONS

In this population of patients with known or suspected coronary artery disease evaluated before nonvascular surgery, DSE had incremental value over clinical, electrocardiographic and rest echocardiographic variables for identifying patients at low, intermediate and high risk for postoperative cardiac events. Ischemia occurring at less than 60% of age-predicted maximal heart rate identified patients at highest risk.

Enhanced detection of ischemic myocardium by transesophageal dobutamine stress echocardiography: comparison with simultaneous transthoracic echocardiography

The diagnostic accuracy of dobutamine stress echocardiography is limited in patients with poor transthoracic acoustic windows. Transesophageal echocardiography (TEE) overcomes these limitations and thus may increase the clinical usefulness of dobutamine stress echocardiography. The present study was designed to compare the diagnostic accuracies of transesophageal and transthoracic dobutamine stress echocardiography for the identification of coronary artery disease (CAD) in a cohort of patients with a higher incidence of poor acoustic windows. Forty-two male patients (mean age, 66 +/- 9 years) underwent dobutamine stress echocardiography with simultaneous transesophageal and transthoracic imaging. Coronary arteriography was performed in 28 patients (67%). Transesophageal imaging adequately visualized 99.6% of left ventricular segments compared with 76.2% visualized by transthoracic imaging (P < 0.0001). There was substantial agreement between the two techniques for segmental wall motion analysis at baseline (kappa 0.76; 95% CI, 0.70-0.82); however, at peak dobutamine dose, agreement was significantly reduced (kappa 0.62; 95% CI, 0.55-0.69). The sensitivity (88% vs 75%), specificity (100% vs 75%), and positive predictive value (100% vs 80%) for the identification of CAD were all superior for transesophageal imaging. Transesophageal imaging correctly identified 11 of the 12 patients (92%) with multivessel disease compared with 5 patients (42%) identified by transthoracic imaging (P < 0.03). There were no major complications. Transesophageal dobutamine stress echocardiography is a safe, feasible, and accurate technique for the identification and risk stratification of patients with CAD. Transesophageal imaging appears to be superior to transthoracic imaging for identifying both the presence and extent of CAD, specifically in patients with poor acoustic windows.

Transesophageal dobutamine stress echocardiography in the evaluation of myocardial ischemia in morbidly obese subjects

BACKGROUND

The evaluation of chest pain or suspected coronary artery disease (CAD) in morbidly obese subjects is limited by the inability of routine diagnostic techniques to adequately image these individuals. Morbidly obese subjects are therefore often inadequately treated or inappropriately treated for presumed CAD.

METHODS AND RESULTS

We prospectively evaluated 23 morbidly obese patients with chest pain using transesophageal dobutamine stress echocardiography (TE-DSE). The mean (+/- SD) weight was 164 +/- 8 kg (range, 118 to 215 kg). We identified nine patients with abnormal TE-DSE findings. Five of these patients subsequently had cardiac catheterization with confirmation of CAD in the regions identified by TE-DSE. Over a follow-up period of 18 +/- 6 months, three cardiac events (non-Q-wave myocardial infarction) occurred in the same group, including two patients without confirmatory cardiac catheterization data. Thus, seven of nine patients with positive results of TE-DSE had objective confirmatory evidence of CAD. No cardiac events were observed in the group with normal TE-DSE over the same follow-up period.

CONCLUSION

TE-DSE is a safe and potentially useful technique for the evaluation of suspected CAD in morbidly obese subjects.

Role of dobutamine stress echocardiography for preoperative cardiac risk assessment before major vascular surgery: a diagnostic tool comes of age

BACKGROUND

Cardiac complications are a major cause for perioperative mortality and morbidity. Also, the presence and severity of underlying coronary artery disease (CAD) determine long-term prognosis after successful surgery.

AIM

This overview evaluates the additional value of dobutamine stress echocardiography (DSE) to common clinical cardiac risk factors and other noninvasive cardiac imaging modalities for perioperative and late cardiac prognosis.

RESULTS

DSE provides theattending physician with preoperative prognostic information for perioperative and long-term prognosis for cardiac events. It also enables the selection of high risk patients for evaluation of cardiac risk reduction therapies.

CONCLUSIONS

DSE is a useful tool for preoperative cardiac risk evaluation in addition to common clinical cardiac risk factors.

The effect of bisoprolol on perioperative mortality and myocardial infarction in high-risk patients undergoing vascular surgery. Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group

BACKGROUND

Cardiovascular complications are the most important causes of perioperative morbidity and mortality among patients undergoing major vascular surgery.

METHODS

We performed a randomized, multicenter trial to assess the effect of perioperative blockade of beta-adrenergic receptors on the incidence of death from cardiac causes and nonfatal myocardial infarction within 30 days after major vascular surgery in patients at high risk for these events. High-risk patients were identified by the presence of both clinical risk factors and positive results on dobutamine echocardiography. Eligible patients were randomly assigned to receive standard perioperative care or standard care plus perioperative beta-blockade with bisoprolol.

RESULTS

A total of 1351 patients were screened, and 846 were found to have one or more cardiac risk factors. Of these 846 patients, 173 had positive results on dobutamine echocardiography. Fifty-nine patients were randomly assigned to receive bisoprolol, and 53 to receive standard care. Fifty-three patients were excluded from randomization because they were already taking a beta-blocker, and eight were excluded because they had extensive wall-motion abnormalities either at rest or during stress testing. Two patients in the bisoprolol group died of cardiac causes (3.4 percent), as compared with nine patients in the standard-care group (17 percent, P=0.02). Nonfatal myocardial infarction occurred in nine patients given standard care only (17 percent) and in none of those given standard care plus bisoprolol (P<0.001). Thus, the primary study end point of death from cardiac causes or nonfatal myocardial infarction occurred in 2 patients in the bisoprolol group (3.4 percent) and 18 patients in the standard-care group (34 percent, P<0.001).

CONCLUSIONS

Bisoprolol reduces the perioperative incidence of death from cardiac causes and nonfatal myocardial infarction in high-risk patients who are undergoing major vascular surgery.

Screening for coronary artery disease

Unidentified coronary artery disease remains a significant cause of premature death and morbidity during the prime of life. The availability of effective interventions for the management of ischemia has provoked new interest in screening for this condition in asymptomatic patients, in the hope of reducing the burden of this condition. Although widespread use of stress testing is ineffective, the use of imaging techniques may offer better accuracy for detection of ischemia. Other tests that identify evidence of atheroma in the peripheral or coronary circulation may be useful to identify patients at risk.

Diagnostic and Prognostic Use of Stress Echocardiography and Radionuclide Scintigraphy

Stress echocardiography and radionuclide scintigraphy are effective diagnostic and prognostic techniques in patients with known or suspected coronary artery disease (CAD), myocardial infarction (MI), chronic left ventricular dysfunction (LVD), and those undergoing noncardiac surgery. Both are sensitive and specific for the detection and extent of CAD. Negative tests confer a high negative predictive value for cardiac events irrespective of clinical risk. Positive studies confer a high positive predictive value for ischemic events in patients with intermediate to high clinical risk. Both provide incremental diagnostic and prognostic information relative to clinical, resting echocardiographic, and angiographic data. Meta-analysis studies have shown that the diagnostic and prognostic information provided by stress echocardiography is comparable with radionuclide scintigraphic stress tests. Stress echocardiography may be more specific for the detection and extent of CAD, whereas radionuclide scintigraphy may be more sensitive for single-vessel disease. Sensitivities are similar for the detection and extent of disease in patients with multivessel CAD.

Dobutamine stress echocardiography for the preoperative evaluation of patients undergoing lung volume reduction surgery

BACKGROUND

Lung volume reduction surgery has been proposed as a bridge to lung transplantation and as definitive therapy for advanced chronic obstructive lung disease. However, patient selection criteria and optimal preoperative assessment have not been clearly defined.

OBJECTIVE

We investigated the feasibility, safety, and value of dobutamine stress echocardiography as a predictor of major early cardiac events in patients who underwent lung volume reduction surgery.

METHODS

The study population consisted of 46 patients (21 men and 25 women, mean age 59 +/- 9 years) who underwent dobutamine stress echocardiography (maximum dose 40 microg. kg(-1). min(-1) plus atropine if needed) 180 days or less before lung volume reduction surgery. Adverse cardiac events were prospectively defined and tabulated during hospitalization after the operation and at subsequent outpatient visits.

RESULTS

Dobutamine stress echocardiography was interpretable in 45 of 46 (98%) patients. There were no adverse events during testing. The studies revealed normal left ventricular systolic function at rest in all patients and normal right ventricular function in all patients but one. Thirteen patients had right ventricular enlargement. Estimated right ventricular systolic pressure was mildly elevated (>40 mm Hg) in 5 patients. Four patients (9%) had stress tests positive for ischemia. There were no perioperative deaths. Follow-up was available for 44 of 45 patients at a duration of 20.0 +/- 7.0 months. Two major adverse cardiac events occurred in the same patient in whom the results of dobutamine stress echocardiography were positive for ischemia (positive predictive value 25%, 95% confidence interval 0% to 83%; negative predictive value 100%, 95% confidence interval 90 to 100%).

CONCLUSION

Despite end-stage chronic obstructive lung disease and poor ultrasound windows, dobutamine stress echocardiography is feasible and safe in patients undergoing evaluation for lung volume reduction surgery. It yields important information on right and left ventricular function and has an excellent negative predictive value for early and late adverse cardiac events.

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.

Pharmacologic stress echocardiography. Dobutamine and arbutamine stress testing

Pharmacologic stress testing is an important noninvasive method for evaluating patients with known or suspected coronary artery disease who are unable to adequately exercise. Pharmacologic stress echocardiography using dobutamine has been developed over the last 10 to 15 years as an alternative to vasodilator stress testing using nuclear perfusion imaging. As experience has grown, digital subtraction echocardiogram has been shown to be a safe, convenient, and reliable method for stress testing in a variety of patient populations. Digital subtraction echocardiogram has comparable sensitivity, specificity, and accuracy when compared to other stress testing methods which employ cardiac imaging and is superior to the exercise echocardiogram. It has certain advantages over nuclear perfusion imaging in terms of cost and convenience. The recent addition of arbutamine echocardiography (which has been shown to be comparable to digital subtraction echocardiogram) provides another alternative method for pharmacologic stress testing. Continued improvement in echocardiographic image quality and the development of new technologies such as tissue harmonic imaging and contrast echocardiography will hopefully improve the echocardiographic evaluation of wall motion therefore increasing the diagnostic accuracy of echocardiographic stress testing.

Exercise echocardiography. Principles, methods, and clinical use

Stress echocardiography is composed of a family of examinations in which various forms of cardiovascular stress are combined with echocardiographic imaging to assist in the diagnosis of coronary artery disease. Exercise cardiography has evolved over the past 20 years into a routinely available clinical tool employed in both university and community hospital settings. This article discusses advantages and disadvantages of using exercise echocardiography.

Prognostic value of dobutamine stress echocardiography in predicting cardiac events in patients with known or suspected coronary artery disease

OBJECTIVES

The study sought to determine the utility of dobutamine stress echocardiography (DSE) in predicting cardiac events in the year after testing.

BACKGROUND

Increasingly, DSE has been applied to risk stratification of patients.

METHODS

Medical records of 1,183 consecutive patients who underwent DSE were reviewed. The cardiac events that occurred during the 12 months after DSE were tabulated: myocardial infarction (MI), cardiac death, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass surgery (CABG). Patient exclusions included organ transplant receipt or evaluation, recent PTCA, noncardiac death, and lack of follow-up. A positive stress echocardiogram (SE) was defined as new or worsened wall-motion abnormalities (WMAs) consistent with ischemia during DSE. Classification and regression tree (CART) analysis identified variables that best predicted future cardiac events.

RESULTS

The average age was 68+/-12 years, with 338 women and 220 men. The overall cardiac event rate was 34% if SE was positive, and 10% if it was negative. The event rates for MI and death were 10% and 8%, respectively, if SE was positive, and 3% and 3%, respectively, if SE was negative. If an ischemic electrocardiogram (ECG) and a positive SE were present, the overall event rate was 42%, versus a 7% rate when ECG and SE were negative for ischemia. Rest WMA was the most useful variable in predicting future cardiac events using CART: 25% of patients with and 6% without a rest WMA had an event. Other important variables were a dobutamine EF <52.5%, a positive SE, an ischemic ECG response, history of hypertension and age.

CONCLUSIONS

A positive SE provides useful prognostic information that is enhanced by also considering rest-wall motion, stress ECG response, and dobutamine EF.

Perioperative Risk Stratification in Patients Undergoing Noncardiac Surgery

Adverse cardiac events during noncardiac surgery are a major cause of morbidity and mortality. As the population ages, greater numbers of patients (including the elderly) are undergoing noncardiac surgical procedures; additional emphasis must therefore be placed on effective preoperative risk assessment. On a national level, the estimated annual expenditure for this process is already $3.7 billion. There is a need for both the specialist and primary care provider to execute a safe, methodical, and cost efficient screening plan. This process should identify both the patients at highest risk and also those at lowest risk. Subsequently, the emphasis should attempt to minimize the overall risk of perioperative complications. The cornerstone of risk assessment requires meticulous history taking, a thorough physical examination, and usually a chest radiograph and an ECG. Five subsequent (basic) steps for the evaluation of patients for noncardiac surgery are outlined here in assessment of clinical markers and the pa- tient's functional capacity, risk of the surgical procedure, the need for noninvasive testing, and when appropriate, the indications for invasive testing. The AHA/ACC Practice Guidelines Committee has outlined a clinical algorithm which provides a stepwise approach to guide the clinician during the decision making process. The purpose of preoperative evaluation is not to "give medical clearance" per se, but rather to evaluate the patient's current medical status, detect stress-induced ischemia in a cost effective manner, and to make recommendations about patient management throughout the entire perioperative period.