Cardiac risk assessment before vascular surgery: a prospective study comparing clinical evaluation, dobutamine stress echocardiography, and dobutamine Tc-99m sestamibi tomoscintigraphy

Pre-operative stress testing in the evaluation of patients undergoing non-cardiac surgery: A systematic review and meta-analysis

Background

Pre-operative stress testing is widely used to evaluate patients for non-cardiac surgeries. However, its value in predicting peri-operative mortality is uncertain. The objective of this study is to assess the type and quality of available evidence in a comprehensive and statistically rigorous evaluation regarding the effectiveness of pre-operative stress testing in reducing 30-day post -operative mortality following non -cardiac surgery.

Methods

The databases of MEDLINE, EMBASE, and CENTRAL databases (from inception to January 27, 2016) were searched for all studies in English. We included studies with pre-operative stress testing prior to 10 different non-cardiac surgery among adults and excluded studies with sample size<15. The data on study characteristics, methodology and outcomes were extracted independently by two observers and checked by two other observers. The primary outcome was 30-day mortality. We performed random effects meta-analysis to estimate relative risk (RR) and 95% confidence intervals (95% CI) in two-group comparison and pooled the rates for stress test alone. Heterogeneity was assessed using I² and methodological quality of studies using Newcastle-Ottawa Quality Assessment Scale. The predefined protocol was registered in PROSPERO #CRD42016049212.

Results

From 1807 abstracts, 79 studies were eligible (297,534 patients): 40 had information on 30-day mortality, of which 6 studies compared stress test versus no stress test. The risk of 30-day mortality was not significant in the comparison of stress testing versus none (RR: 0.79, 95% CI = 0.35–1.80) along with weak evidence for heterogeneity. For the studies that evaluated stress testing without a comparison group, the pooled rates are 1.98% (95% CI = 1.25–2.85) with a high heterogeneity. There was evidence of potential publication bias and small study effects.

Conclusions

Despite substantial interest and research over the past 40 years to predict 30-day mortality risk among patients undergoing non-cardiac surgery, the current body of evidence is insufficient to derive a definitive conclusion as to whether stress testing leads to reduced peri-operative mortality.

Actual impact of screening for myocardial ischemia with single-photon emission tomography among patients undergoing peripheral vascular interventions

The present study provides actual data with regard to the prevalence of myocardial ischemia among patients under contemporary cardiovascular prevention strategies undergoing peripheral vascular interventions. We included a total of 200 consecutive patients who underwent gated single-photon emission computed tomography myocardial perfusion study between January 2012 and January 2014 as preoperative evaluation for peripheral vascular interventions at our institution. The baseline medical treatment comprised aspirin (81%), statins (79%), and β-blockers (54%). Thirty-two (16%) patients underwent carotid revascularization; 69 (34.5%) patients underwent lower limb revascularization, and 99 patients underwent aortic interventions. Twenty-six (13%) patients showed evidence of myocardial ischemia, with an extensive ischemic burden identified in seven (3.5%) patients. Within the group of patients with peripheral vasculopathy, those with lower limb arteriopathy had a higher prevalence of ischemia. According to the results of the myocardial perfusion study, the cardiology in charge indicated invasive coronary angiography in 11/26 (42%) patients with evidence of myocardial ischemia. Seven of the 11 (64%) patients who had coronary angiography were revascularized. After a mean follow-up of 24 months, no cardiovascular adverse events were detected.

Mechanism of decreased sensitivity of dobutamine associated left ventricular wall motion analyses for appreciating inducible ischemia in older adults

BACKGROUND

Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.

METHODS

During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.

RESULTS

Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).

CONCLUSIONS

During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

TRIAL REGISTRATION

This study was registered with Clinicaltrials.gov (NCT00542503).

Proximal direct endarterectomy combined with simultaneous distal endovascular therapy for chronic full-length occlusion of the superficial femoral artery in elderly patients

BACKGROUND AND PURPOSE

The most proximal ostial site of the chronic occlusive superficial femoral artery is not suitable for ballooning or stenting because the deep femoral artery may be occluded by these procedures. Thus, the feasibility of performing an open endarterectomy for the occluded ostium of the superficial femoral arteries combined with an endovascular therapy for the remaining distal site was evaluated.

METHODS

Eleven critically ischemic limbs in 10 elderly patients with poor general health were enrolled. They had full-length occlusion of the superficial femoral artery involving its ostium. The ostial site was managed with an open endarterectomy followed by endovascular therapy for the remaining distal site.

RESULTS

All procedures were successfully performed. All patients experienced pain relief, and the wounds healed. During the follow-up observation period (average: 23.9 ± 14.7 months), nine patients died. None of the patients, including those who had lost patency of the superficial femoral artery, received major amputation.

CONCLUSION

Elderly patients, including those who were in terminal stage, were able to withstand the operation, and their postoperative quality of life was not compromised. Although the patency following the surgery was limited, sparing the deep femoral artery could either prevent or delay the recurrence of critical limb ischemia.

Imaging of Abdominal Aortic Aneurysm: the present and the future

Abdominal Aortic Aneurysm (AAA) is a common, progressive, and potentially lethal vascular disease. A major obstacle in AAA research, as well as patient care, is the lack of technology that enables non-invasive acquisition of molecular/cellular information in the developing AAA. In this review we will briefly summarize the current techniques (e.g. ultrasound, computed tomography, and magnetic resonance imaging) for anatomical imaging of AAA. We also discuss the various functional imaging techniques that have been explored for AAA imaging. In many cases, these anatomical and functional imaging techniques are not sufficient for providing surgeons/clinicians enough information about each individual AAA (e.g. rupture risk) to optimize patient management. Recently, molecular imaging techniques (e.g. optical and radionuclide-based) have been employed to visualize the molecular alterations associated with AAA, which are discussed in this review. Lastly, we try to provide a glance into the future and point out the challenges for AAA imaging. We believe that the future of AAA imaging lies in the combination of anatomical and molecular imaging techniques, which are largely complementary rather than competitive. Ultimately, with the right molecular imaging probe, clinicians will be able to monitor AAA growth and evaluate the risk of rupture accurately, so that the life-saving surgery can be provided to the right patients at the right time. Equally important, the right imaging probe will also allow scientists/clinicians to acquire critical data during AAA development and to more accurately evaluate the efficacy of potential treatments.

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.

How is risk defined in high-risk surgical patient management?

The definition of risk in surgical patients is a complex and controversial area. Generally risk is poorly understood and depends on past individual and professional perception, and societal norms. In medical use the situation is further complicated by practical considerations of the ease with which risk can be measured; and this seems to have driven much risk assessment work, with a focus on objective measurements of cardiac function. The usefulness of risk assessment and the definition of risk is however in doubt because there are very few studies that have materially altered patient outcome based on information gained by risk assessment. This paper discusses these issues, highlights areas where more research could usefully be performed, and by defining limits for high surgical risk, suggests a practical approach to the assessment of risk using risk assessment tools.

Carotid Endarterectomy: Experience in 5425 Cases

From 1992 to December 2002, 3967 patients (2619 males; 1348 females) with a mean age of 68.4A years (range 32-92) underwent 5425 carotid endarterectomy (CE) procedures at our institute. Neurological history was positive for stroke in 1130 cases (21%) and for transient ischemic attack (TIA) in 2121 cases (39%). In 2174 cases (40%) patients were neurologically asymptomatic or presented nonspecific symptoms. Our current clinical protocol has been designed to optimize resources and reduce complications. Some of the major features, along with the respective percentages in this series, are as follows. Duplex scanning was performed at a validated laboratory as the principal preoperative exam (86.9%). Locoregional anesthesia and neurological monitoring were performed during carotid cross-clamping (96.3%). Selective shunting was carried out with a Javid shunt (10.7%). The choice of surgical technique was made according to carotid anatomy and cerebral tolerance of cross-clamping. Those used were a standard technique (now abandoned, 12.1%), synthetic patching (46.4%), and eversion endarterectomy (41.5%). Intraoperative completion arteriography was routinely performed for eversion endarterectomy and only in dubious cases with other techniques. The option of staying in an postoperative intensive care unit (ICU) was available (selective use, 2%). In uncomplicated cases, early discharge (after 1.5 postoperative days) was considered safe. The overall perioperative mortality was 0.37% (20/5425). Causes of death were myocardial infarction in seven cases, ischemic stroke in six cases, hemorrhagic stroke in five cases, respiratory failure caused by cervical hematoma in one case, and wound infection in one case. Perioperative neurological morbidity was 1.31% (71/5425); there were 43 major and 28 minor strokes. In conclusion, CE is effective for stroke prevention when there is significant symptomatic and asymptomatic carotid stenosis, as low mortality and morbidity may be achieved in an experienced center. At our institute, the reduction of costs did not have negative consequences on the quality of the surgical care.

Myocardial perfusion scintigraphy: the evidence

This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by comparison with the numbers of revascularisations and coronary angiograms performed. Furthermore, MPS activity levels in this country fall far short of those in comparable European countries, with about half as many scans being undertaken per year. Currently, the number of MPS studies performed annually in the UK is 1,200/million population/year. We estimate the real need to be 4,000/million/year. The current average waiting time is 20 weeks and we recommend that clinically appropriate upper limits of waiting time are 6 weeks for routine studies and 1 week for urgent studies.

Risk assessment by myocardial perfusion imaging for coronary revascularization, medical therapy, and noncardiac surgery

Stress myocardial perfusion imaging (MPI) has become an important tool in risk stratification of patients with known coronary artery disease. A normal myocardial perfusion scan has a high negative predictive value and is associated with low annual mortality rate (< 1%). Patients with extensive ischemia (> 20% of the left ventricle), defects in more than 1 coronary vascular territory, transient or persistent left ventricular cavity dilation, and ejection fraction less than 45% have a high annual mortality rate (> 3%). Those patients should undergo coronary revascularization whenever feasible, as the cardiac event rate increases in proportion to the magnitude of the jeopardized myocardium. Stress MPI can be used to demonstrate ischemia in patients with symptoms early after coronary artery bypass surgery (< 5 years) or in those without symptoms late (>/= 5 years) after coronary artery bypass surgery. With respect to patients who underwent percutaneous interventions, stress MPI can help detect in-stent restenosis early after the intervention (3-6 months) or assess the progression of native coronary disease afterward. Since preliminary data suggest that a reduction in the perfusion defect size may translate to a reduction of coronary events, stress MPI can help assess the efficacy of medical management of coronary disease. Finally, stress MPI is indicated for perioperative cardiac risk stratification for noncardiac surgery in patients with intermediate risk predictors (mild angina, prior myocardial infarction or heart failure symptoms, diabetes mellitus, renal insufficiency) and poor functional capacity or in those who undergo high-risk surgery with significant implications in further preoperative management.

[Stress echocardiography in the pre-operative evaluation of patients undergoing major vascular surgery. Are results comparable with dypiridamole versus dobutamine stress echo?]

INTRODUCTION

[corrected] Perioperative cardiovascular complications are an important cause of post-surgical morbility and mortality in patients undergoing major vascular surgery. Dobutamine Stress Echo is considered one of the methods of choice in the detection of coronary artery disease in this subgroup of patients.

OBJECTIVES

. Our aim was to analyze if dipyridamole stress echocardiography could be used as an alternative to Dobutamine Stress Echo in the perioperative evaluation of patients in need of major vascular surgery.

PATIENTS AND METHOD

The result of consecutives dypiridamole and dobutamine stress exams prior to vascular surgery were reviewed. We analyzed if those patients with a positive stress echo presented a higher number of cardiac events during and after surgery than those with negative stress echo. The negative and positive predictive values were calculated for both techniques.

RESULTS

133 stress exams were analysed: 39 with dobutamine and 94 with dipyridamole. Of the 39 dobutamine studies 2 were positive, 29 negatives and 8 non conclusive. Of the 94 dypiridamole studies 13 were positive and 81 negatives. None of the patients with a positive dobutamine echo underwent surgery. The negative predictive value for dobutamine echo was 96.5%, quite similar to that of dypiridamole stress echo (97.5%).

CONCLUSION

Dipyridamole stress echocardiography is a valid alternative to dobutamine echocardiography in the pre-surgical evaluation of patients undergoing major vascular surgery.

Cardiac Investigation and Intervention Prior to Thoraco-abdominal Aneurysm Repair: Coronary Angiography in 35 Patients

OBJECTIVE

retrospective studies indicate a high risk of cardiac events in patients undergoing thoraco-abdominal aneurysm repair. We aimed to determine the prevalence of coronary disease in these patients, define the role of non-invasive cardiac testing and assess the short-term outcome of coronary re-vascularisation.

DESIGN

a prospective cohort study of consecutive patients referred to a single surgeon.

MATERIALS AND METHODS

forty patients recruited over 16 months (Type I, 6; II, 11; III, 8; IV, 15). Dobutamine stress echocardiography, coronary angiography and coronary re-vascularisation (PTCA or CABG) were performed according to a pragmatic protocol. Main outcome measures were the prevalence of coronary artery disease, sensitivity and specificity of clinical assessment and non-invasive cardiac testing, and adverse events associated with coronary investigation and intervention.

RESULTS

seven patients (17.5%) were stratified as having high perioperative cardiac risk. The majority of patients (23, 57.5%) had no cardiac risk factor other than the operation type. Five patients (12.5%) had inducible ischaemia on non-invasive testing. Fourteen patients (40%) had haemodynamically significant coronary artery stenoses, of whom 12 (34%) underwent coronary revascularisation. Dobutamine stress echocardiography demonstrated 100% specificity and 71% sensitivity for the detection of significant coronary artery lesions. Coronary re-vascularisation by three-vessel bypass grafting was complicated by non-fatal stroke in one patient. Thirty-five patients (87.5%) proceeded to aneurysm repair. No patient who had been adequately investigated suffered a cardiac complication.

CONCLUSIONS

the 40% prevalence of coronary artery disease in these patients is comparable to that of other patients undergoing arterial surgery. Non-invasive testing proved beneficial, both in screening low-risk patients and planning intervention in patients at higher risk. An aggressive approach to intervention was associated with an acceptable complication rate and favourable short-term outcome.

Dobutamine stress myocardial perfusion imaging

In patients with limited exercise capacity and (relative) contraindications to direct vasodilators such as dipyridamole or adenosine, dobutamine stress nuclear myocardial perfusion imaging (DSMPI) represents an alternative, exercise-independent stress modality for the detection of coronary artery disease (CAD). Nondiagnostic test results (absence of reversible perfusion defects with submaximal stress) do occur in approximately 10% of patients. Serious side effects during DSMPI are rare, with no death, myocardial infarction or ventricular fibrillation reported in three DSMPI safety reports for a total of 2,574 patients. On the basis of a total number of 1,014 patients reported in 20 studies, the sensitivity, specificity and accuracy of the test for the detection of CAD were 88%, 74% and 84%, respectively. Mean sensitivities for one-, two- and three-vessel disease were 84%, 95% and 100%, respectively. The sensitivity for detection of left circumflex CAD (50%) was lower, compared with that for left anterior descending CAD (68%) and right CAD (88%). The sensitivity of predicting multivessel disease by multiregion perfusion abnormalities varied widely, from 44% to 89%, although specificity was excellent in all studies (89% to 94%). In direct diagnostic comparisons, DSMPI was more sensitive, but less specific, than dobutamine stress echocardiography and comparable with direct vasodilator myocardial perfusion imaging. In the largest prognostic study, patients with a normal DSMPI study had an annual hard event rate less than 1%. An ischemic scan pattern provided independent prognostic value, with a direct relationship between the extent and severity of the perfusion defects and prognosis. In conclusion, DSMPI seems a safe and useful nonexercise-dependent stress modality to detect CAD and assess prognosis.

Influence of respiratory disease on perioperative cardiac risk in patients undergoing elective surgery for abdominal aortic aneurysm

We retrospectively reviewed perioperative cardiac complications in a series of 214 patients who underwent surgical treatment for infrarenal aortic aneurysm between 1992 and 1996. There were 192 men and 22 women, with a mean age of 68.3 years. Cardiac risk factors included angina in 28% of patients and previous myocardial infarction in 25%. Resting electrocardiography was normal in 80 patients (37.5%). Depending on clinical findings, thallium-201 scintigraphy was undertaken in 76 patients (35.5%) and led to elective coronary arteriography in 22 patients (10%). Results of coronary arteriography revealed lesions in 14 patients. Aortic reconstruction was performed by the transperitoneal route in all patients. Procedures consisted of aortoaortic bypass (63%), aortobiiliac bypass (27.5%), or aortobifemoral bypass (9.5%). Nine patients (4.2%) died within the first 30 postoperative days. The cause of death was myocardial infarction (MI) in two patients (1%), colonic necrosis in two (1%), acute pancreatitis in one (0.5%), acute renal insufficiency in three (1.4%), and multiple organ failure in one patient (0.5%). Nonfatal cardiac complications were observed in 15 patients (7%). Statistical analysis of risk factors revealed two predictors of perioperative cardiac complications, i.e., history of chronic bronchitis and reoperation. On review of the literature, we cannot propose a routine preoperative work-up. Prospective multicentric studies are needed to determine the predictive value of current preoperative screening methods.

Dobutamine stress echocardiography: safety in diagnosing coronary artery disease

Dobutamine stress echocardiography is considered a relatively well-tolerated diagnostic modality, effective in the management of patients with known or suspected coronary artery disease. Adverse effects during testing are relatively frequent, precluding the achievement of a diagnostic end-point in about 5 to 10% of tests. These adverse effects, mostly tachyarrhythmias and arterial hypotension, are usually minor and self limiting. However, severe life-threatening complications, as well as death, also occur. By analysing Medline-quoted literature up to March 1999, we found 35 original studies from a single institution with more than 100 patients, as well as 2 multicentre studies, concerning the feasibility and safety of dobutamine stress echocardiography. In a cumulative total of 26438 tests performed, 79 life-threatening complications (such as acute myocardial infarction, asystole, ventricular fibrillation, sustained ventricular tachycardia or severe symptomatic hypotension) have been reported, giving an incidence of 1 severe adverse reaction per every 335 examinations. In addition, 29 isolated case reports have been published describing life-threatening complications during dobutamine echocardiography. In case reports, 2 deaths have been described, both due to acute cardiac rupture in patients with recent inferior myocardial infarction. Severe adverse reactions during dobutamine echocardiography can be ischaemia independent, and are independent of operator experience and are unpredictable; some complications can be late occurring and long lasting. As a consequence, the procedure must be clearly indicated, written informed consent has to be obtained from the patient, an attending physician must be present during testing, and long term observation of outpatients is useful in order to manage late complications. In conclusion, while the safety of dobutamine stress echocardiography was reported to be outstanding in early reports, further experience presents a substantially more worrying picture. This must be taken into account by both physicians and patients when assessing the risk-benefit profile of the procedure.

Technetium Tc 99m sestamibi myocardial perfusion imaging: current role for evaluation of prognosis

Like 201Tl imaging, technetium Tc 99m sestamibi (MIBI) myocardial imaging can be used with exercise and pharmacologic testing to assess the presence of coronary artery disease. An increasing body of literature indicates that MIBI can also be used to assess risk of future cardiac events such as myocardial infarction or death. This article summarizes the current status of MIBI imaging for evaluating prognosis in patients with known or suspected coronary artery disease.

Comparison of dipyridamole stress echocardiography and perfusion scintigraphy for cardiac risk stratification in vascular surgery patients

Dipyridamole single-photon emission computed tomography (SPECT) has a high negative predictive value for perioperative cardiac events, but events are infrequent in patients with a positive test. In contrast, dipyridamole echocardiography is more selective for detection of multivessel disease and thus may have a greater specificity for cardiac events. We therefore compared the ability of dipyridamole SPECT and echocardiography to predict perioperative and long-term cardiac events in 133 patients referred for vascular surgery. The group was also evaluated based on clinical features and ejection fraction. Four patients had surgery cancelled because of high risk and were excluded from further analysis. Among the 129 remaining patients, 21 had coronary revascularization (n=12) or an early cardiac end point (n=9). The sensitivity of SPECT for the prediction of early events (90%) was not significantly different from that of echocardiography (66%, p=NS). The specificity of SPECT (68%) was less than that of echocardiography (88%, p <0.001%), as was the accuracy (72% vs 84%, p=0.02). These findings were replicated after exclusion of patients with treatment end points. During long-term follow-up, 12 patients experienced > or = 1 event: 6 died from cardiac causes, 4 underwent revascularization, and 3 had myocardial infarction. Thus, the specificity of SPECT and echocardiography for late events were 58% and 80%, respectively (p <0.001). The 3-year survival of patients without ischemia during echocardiography or at SPECT was not different (93% vs 94%, p=NS).