Dipyridamole-thallium Scanning Research Articles

Does preoperative dipyridamole-thallium scanning reduce 90-day cardiac complications and 1-year mortality in patients with femoral neck fractures undergoing hemiarthroplasty?

BackgroundThis study aimed to evaluate the effect of dipyridamole-thallium scanning (DTS) on the rates of 90-day cardiac complications and 1-year mortality in patients with a femoral neck fracture treated with hemiarthroplasty.MethodsBetween 2008 and 2015, 844 consecutive patients who underwent cemented or cementless hemiarthroplasty were identified from the database of a single level-one medical center. One-hundred and thirteen patients (13%) underwent DTS prior to surgery, and 731 patients (87%) did not. Patient characteristics, comorbidities, surgical variables, and length of the delay until surgery were recorded. A propensity score-matched cohort was utilized to reduce recruitment bias in a 1:3 ratio of DTS group to control group, and multivariate logistic regression was performed to control confounding variables.ResultsThe incidence of 90-day cardiac complications was 19.5% in the DTS group and 15.6% in the control group (p = 0.343) among 452 patients after propensity score-matching. The 1-year mortality rate (10.6% vs 13.3%, p = 0.462) was similar in the two groups. In the propensity score-matched patients, utilization of DTS was not associated with a reduction in the rate of 90-day cardiac complications (matched cohort, adjusted odds ratio [aOR] = 1.32; 95% confidence interval [CI] 0.75–2.33, p = 0.332) or the 1-year mortality rate (aOR = 0.62; 95% CI 0.27–1.42, p = 0.259). Risk factors for cardiac complications included an American Society of Anesthesiologists grade ≥ 3 (OR 3.19, 95% CI 1.44–7.08, p = 0.004) and pre-existing cardiac comorbidities (OR 5.56, 95% CI 3.35–9.25, p < 0.001). Risk factors for 1-year mortality were a long time to surgery (aOR 1.15, 95% CI 1.06–1.25, p = 0.001), a greater age (aOR 1.05, 95% CI 1.00 to 1.10, p = 0.040), a low body mass index (BMI; aOR 0.89, 95% CI 0.81–0.98, p = 0.015), and the presence of renal disease (aOR 4.43, 95% CI 1.71–11.46, p = 0.002).DiscussionPreoperative DTS was not associated with reductions in the rates of 90-day cardiac complications or 1-year mortality in patients with a femoral neck fracture undergoing hemiarthroplasty. The necessity for DTS should be re-evaluated in elderly patients with femoral neck fractures, given that this increases the length of the delay until surgery.Level of evidencePrognostic level III

A study on the role of ECG, echo and dipyridamole thallium scan in identifying early myocardial damage in systemic sclerosis

A study on the role of ECG, echo and dipyridamole thallium scan in identifying early myocardial damage in systemic sclerosis

MEDICAL THERAPY CAN SIGNIFICANTLY IMPROVE EXERCISE TOLERANCE IN ISOLATED DIASTOLIC HEART FAILURE.

Background Patients with preserved left ventricular ejection fraction and signs and symptoms of heart failure are defined as having diastolic heart failure (DHF). Evidence-based therapies for this disorder are not clearly defined. We present three cases, which derived significant benefit from different medical regimens tailored to the individual patient. Case 1 A 66-year-old, hypertensive male referred for assessment of his progressive shortness of breath (SOB). SOB had worsened over the past 6 months to the point of being unable to walk half a block without symptoms. Echocardiogram revealed a preserved ejection fraction with reversal of the E:A ratio. Lung/heart ratio on dipyridamole thallium scan was elevated at 0.67. His DHF was treated by starting ramipril and increasing his metoprolol. After treatment, he noted that he was able to use his stationary bike for 15 to 20 minutes without dyspnea. Case 2 A 49-year-old hypertensive obese female presented with retrosternal chest discomfort associated with worsening SOB after walking only 10 feet. Cardiac catheterization revealed an elevated end-diastolic pressure of 40 mm Hg but no evidence of coronary artery disease. Echocardiogram showed moderate left ventricular hypertrophy with a preserved ejection fraction. She was initially started on benazepril and metoprolol, with spironolactone added later. Her distance walked had increased to one block since beginning treatment. Case 3 A 54-year-old female presented to the emergency department complaining of exhaustion and SOB after walking only one-tenth of a mile for the past 3 weeks. Cardiac catheterization showed nonobstructive coronaries with an LVEDP of 38mmHg. Echocardiogram showed a preserved ejection fraction with a right ventricular systolic pressure of 53 mm Hg and impaired relaxation. She was initially treated with losartan, spironolactone, Isordil, Lasix, and hydrochlorothiazide. Verapamil was added later in a follow-up visit, with further improvement in symptoms. Later, verapamil was stopped and Toprol XL was added. However, as her symptoms of SOB worsened, verapamil was reinstated. SOB improved by restarting the verapamil. She is now able to walk 450 feet with relative ease, whereas prior to hospitalization, she could only walk 50 feet before becoming tired and SOB. Conclusions We presented three patients with DHF who responded to individually tailored medical regimens, resulting in a 100 to 1,000% increase in exercise tolerance. Medical therapy for DHF can produce striking improvement in quality of life. Precise medical therapy and hierarchy of its implementation remain to be defined.

Cardiovascular Magnetic Resonance Imaging Has Much to Offer in the Assessment of Renal Transplant Recipients

To the Editor: In her review of cardiac assessment for renal transplantation, Pilmore (American Journal of Transplantation 2006; 6: 659–665) comprehensively assesses current methods for screening for coronary artery disease in patients with end-stage renal failure (ESRF) using myocardial perfusion studies with thallium scintography, dobutamine echocardiography and dipyridamole thallium scans (1Pilmore H Cardiac assessment for renal transplantation..Am J Transplant. 2006; 6: 659-665Abstract Full Text Full Text PDF PubMed Scopus (51) Google Scholar). Recent developments in cardiac imaging with cardiac magnetic resonance imaging (CMR) suggest that this technique may also have much to offer in work-up of the renal transplant recipient. This is a promising method for noninvasive evaluation of myocardial perfusion as well as allowing detailed assessment of cardiac structure and function. Studies suggest that CMR is more accurate than radionuclide imaging at detecting small areas of myocardial infarction (2Wagner A Mahrholdt H Holly TA et al.Contrast-enhanced MRI and routine single photon emission computed tomography (SPECT) perfusion imaging for detection of subendocardial myocardial infarcts: An imaging study..Lancet. 2003; 361: 374-379Abstract Full Text Full Text PDF PubMed Scopus (1075) Google Scholar), which are likely to have therapeutic and prognostic implications for patients on the transplant list. Furthermore, while Pilmore rightly points out that data are lacking on the benefits of pre-emptive coronary revascularization of patients with ESRF, CMR can identify viable myocardium, therefore allowing appropriate selection of individual patients for revascularization procedures (3Kim RJ Wu E Rafael A et al.The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction..N Engl J Med. 2000; 343: 1445-1453Crossref PubMed Scopus (2591) Google Scholar). This is particularly important given the high mortality of patients with ESRF undergoing coronary revascularization. Our experience using CMR as research tool in patients being assessed for renal transplantation has confirmed a high incidence of myocardial ischemia (Figure 1) (4Mark PB Johnston N Groenning BA et al.Redefinition of uremic cardiomyopathy by contrast-enhanced cardiac magnetic resonance imaging..Kidney Int. 2006; (Epub 2006 Mar 1.)Abstract Full Text Full Text PDF Scopus (205) Google Scholar). Moreover with CMR we found that left ventricular dysfunction did not occur in the absence of myocardial ischemia, suggesting that left ventricular dysfunction in a patient with ESRF is highly suggestive of underlying coronary artery disease. This should be investigated aggressively with angiography in addition to medical therapy with beta-blockade, anti-platelet therapy and renin-angiotensin system inhibition as appropriate. Prospective study of patients studied with CMR is ongoing to assess the impact of its use and the relationship between CMR findings and long-term outcomes for both transplanted patients and those remaining on the wait list. From a practical point of view CMR is noninvasive, does not use ionizing radiation (unlike radionuclide studies and CT angiography) and therefore is appropriate for performing repeated scans on transplant listed patients. Stress perfusion CMR, using pharmacological agents such as adenosine to induce coronary hyperaemia, has a high sensitivity and specificity for the presence of significant coronary artery stenoses (5Plein S Radjenovic A Ridgway JP et al.Coronary artery disease: Myocardial perfusion MR imaging with sensitivity encoding versus conventional angiography..Radiology. 2005; 235: 423-430Crossref PubMed Scopus (115) Google Scholar). Although nephrotoxicity has been reported with gadolinium-based contrast agents used for CMR, these are generally felt to be safe in renal insufficiency, and certainly safer than radiocontrast agents used for both conventional and CT coronary angiography. This allows CMR to facilitate comprehensive noninvasive cardiac assessment of the patient with advanced kidney disease, hoping to undergo pre-emptive renal transplantation, by detailing cardiac structure, function, assessing myocardial perfusion and viability, should revascularization be contemplated. The argument could be made that CMR is expensive and not widely available. As its use is expanding and it integrates the results of multiple tests in a safe repeatable manner, potentially reducing the need for invasive investigations, these obstacles may be surmounted. The renal transplant community is ideally placed to embrace this technology that may progress from being a research tool to representing a ‘one stop’ screening investigation for potential transplant recipients. P.B. Mark is funded by a British Heart Foundation Junior Fellowship.

CASE 5—2000 redo coronary revascularization without cardiopulmonary bypass

The patient was a 53-year-old man with a history of 3 previous coronary artery bypass graft (CABG) operations (1978, 1991, 1997) who presented to an outside hospital with severe unstable angina and tachycardia (heart rate 140 BPM). Because of his extensive cardiac history and unfavorable coronary anatomy, he was deemed a poor surgical candidate for a fourth reoperation. During his third revascularization procedure, the right ventricle had been entered at sternotomy; the aorta was also noted to be densely adherent and heavily calcified with no sites for proximal graft anastomosis (vein grafts to the left anterior descending and right coronary artery had their proximal anastomoses to a previously existing circumflex saphenous vein graft near the coronary graft ostium). The heart was supplied entirely by this single vein graft with its 3 divisions; all native coronary vessels were totally occluded. The patient was transferred to this institution for further surgical evaluation. Past medical history was significant for myocardial infarction, permanent pacemaker, history of hepatitis C, gastritis, depression, bipolar disorder, posttraumatic stress disorder, remote 30 pack-year smoking history, recent history of alcohol abuse, and history of marijuana use. The patient was not considered a transplant candidate. Medications at presentation included captopril, 12.5 mg orally three times a day; furosemide, 40 mg orally two times a day; omeprazole (prilosec), 20 mg orally daily; heparin infusion, 1200 U/h; digoxin, 0.125 mg orally daily; aspirin daily; sertraline (Zoloft), 50 mg orally daily; and diazepam, 5 mg orally daily. The preoperative electrocardiogram (ECG) showed an incomplete left bundle-branch block with diffuse STand T-wave abnormalities. Pulmonary function tests showed forced expiratory volume in 1 second, 2.03 L, and forced vital capacity, 2.87 L. A preoperative chest radiograph showed cardiomegaly with pulmonary congestion. Laboratory data, including a complete blood count, renal and electrolyte panel, coagulation profile, and liver panel, were normal except for activated partial thromboplastin time, 46.7 seconds; hematocrit, 31.5%; and elevated CK-MB fraction suggestive of acute non–Q wave myocardial infarction. Preoperative testing included a dual isotope cardiac study, which showed a large reversible perfusion defect involving the anteroapical region; a small reversible perfusion defect involving the septum, left ventricular hypokinesia, and a calculated left ventricular ejection fraction of 19%. A dipyridamolethallium scan was strongly positive for global ischemia. A transthoracic echocardiogram was significant for severe global left ventricular dysfunction, normal right ventricular function, and mild-to-moderate mitral regurgitation. Cardiac catheterization revealed a single 50% proximal stenosis of the circumflex saphenous vein graft compromising flow to the existing associated right coronary artery and left anterior descending artery vein grafts, whose proximal anastomotic sites were distal to this obstruction. Despite aggressive medical management, the patient could not be weaned from intra-aortic balloon pump support. Percutaneous transluminal coronary angioplasty was not considered to be an option. He presented for elective coronary artery bypass graft (CABG) surgery without cardiopulmonary bypass by a left thoracotomy approach. His estimated operative risk was 50%. In the operating room, routine monitors, a femoral arterial catheter, a femoral venous catheter (8F introducer sheath), and a left internal jugular 12F central venous pressure (CVP) catheter were placed. External defibrillator pads were also applied. A right internal jugular pulmonary artery catheter and a left femoral intra-aortic balloon pump at 1:1 counterpulsation were already in situ. The patient was on no inotropic support at this time. Preinduction vital signs were heart rate (HR), 80 beats/ min; mean arterial pressure (MAP), 95 mmHg; CVP, 17 mmHg; pulmonary artery pressure (PAP), 62/39 mmHg; and cardiac index (CI), 2.8 L/min/m2. The ECG showed diffuse ST-T wave changes in all leads. Anesthetic induction with etomidate, midazolam, and fentanyl proceeded uneventfully. A 39F leftsided double-lumen endotracheal tube was inserted easily, and the position was verified with a pediatric fiberoptic bronchoscope. Postinduction transesophageal echocardiography (TEE)

Intravenous dipyridamole thallium imaging V combined arm-leg cycle stress testing of patients unable to exercise on the treadmill.

Rehabilitation patients who will undergo noncardiac surgery or strenuous rehabilitation programs often cannot exercise to greater than 85% of predicted maximal heart rate as required for valid treadmill testing. Because many patients have known or suspected coronary artery disease, greatly increasing their risk for a cardiac event, dipyridamole thallium scans are usually performed, despite a cost of approximately $1400, patient radiation exposure, and the need for a gamma camera. Instead, arm-leg cycle stress testing can be continued to an appropriately high heart rate, is done in the physician's office with an electrocardiograph machine and a blood pressure cuff, and costs $250. This study describes nine patients who had both dipyridamole thallium scans and arm-leg cycle ergometry. Four awaited peripheral vascular surgery, one needed bilateral knee replacements, one was an amputee, and three had claudication. Six had documented and three had suspected coronary disease. In eight of nine patients, the electrocardiograms during both dipyridamole thallium imaging and ergometry were in agreement as to the presence or absence of ischemia (kappa statistic, 0.7273; P = 0.0117). In seven of nine patients, thallium images and ergometry agreed (78% concurrence). To achieve 90% agreement between dipyridamole thallium scans and cycle results, however, 68 patients would have to be studied. In this preliminary study, arm-leg ergometry was feasible in all patients and seemed cost-effective and useful for detecting myocardial ischemia. Clinically, if the ergometry were inconclusive, dipyridamole thallium scans could be performed subsequently to obtain the needed information.

Is coronary angiography necessary for vascular surgery patients who have positive results of dipyridamole thallium scans?

Because dipyridamole thallium (DT) scanning is a useful predictor of perioperative cardiac events, a positive results of a DT scan is frequently the basis for performing more invasive cardiac evaluation and for consideration for performing coronary revascularization procedures before performing peripheral vascular surgery. The rationale for this approach has been that the treatment of anatomically significant coronary artery disease would lower the risk of performing a subsequent vascular operation. However, the benefit of performing aggressive diagnostic and therapeutic cardiac procedures in such patients remains unproved. To examine this issue, data from patients who underwent coronary angiography because of thallium redistribution were compared with data from matched control subjects who underwent peripheral vascular operations without further cardiac evaluation. The medical records of 70 consecutive patients who underwent coronary angiography because of the presence of two or more segments of redistribution on DT scan were reviewed and compared with 70 other patients matched with respect to age, gender, peripheral vascular operation, and number of segments of redistribution on DT scan who did not undergo additional cardiac evaluation. DT scans were performed on 934 preoperative peripheral vascular surgery patients to help in the assessment of operative risk. Ischemic responses, defined as two or more segments of redistribution, were observed in 297. Of these, 70 underwent cardiac catheterization and 25 underwent coronary revascularization procedures. Adverse outcomes affected 46% of the coronary angiography group and 44% of the control group (p = NS). Patients who underwent coronary angiography and were considered for myocardial revascularization had fewer cardiac events with a subsequent vascular operation than did the control subjects. However, any possible benefit from invasive cardiac evaluation was offset by the three deaths and two myocardial infarctions (MIs) that complicated the cardiac evaluation. There was no significant difference between the angiography group and the matched control subjects with respect to perioperative nonfatal MI (13% vs 9%), fatal MI (4% vs 3%), late nonfatal MI (16% vs 19%), or late cardiac death (10% vs 13%). In long-term follow-up, MIs occurred later in patients who underwent coronary angiography than the control subjects (p = 0.049), but this difference was not associated with an improvement in the overall survival rate. The risks of extended cardiac evaluation and treatment did not produce any improvement in either the perioperative or the long-term survival rate. For most vascular surgery patients who have a positive result of a DT scan, coronary angiography does not provide any additional useful information.

Reduced Morbidity and Mortality Following Carotid Endarterectomy: The Value of Preoperative Cardiac Screening

Carotid endarterectomy can be recommended for stroke prophylaxis when performed with low perioperative cardiac morbidity and mortality. In this study the authors evaluate the effectiveness of a cardiac screening protocol using dipyridamole-thallium scintig raphy to identify and treat coexistent coronary artery disease (CAD). The authors reviewed the medical records of 164 patients undergoing carotid endarterectomy between 1988 and 1993 at the John L. Doyne Hospital and at the Zablocki Veterans Administration Hospital in Milwaukee, Wisconsin. Results of the preop erative cardiac evaluations and the incidence of perioperative cardiac events were recorded. Forty patients without any evidence of cardiac disease by history or electrocardio gram went on to surgery without further screening. Eight patients underwent coronary catheterization without dipyridamole-thallium scan, owing to the severity of their cardiac symptoms. A cardiology consultation and dipyridamole-thallium scan were obtained preoperatively in the remaining 116 patients with a history of CAD. Of these 116 patients, 62 (53.4%) were diagnosed as normal. Thirty-five (30%) scans demonstrated reversible reperfusion defects, leading to preoperative coronary angiography in 17 patients and to cardiac revascularizations in 8. Nineteen (16.4%) scans demonstrated a fixed perfusion defect; 3 of these patients underwent coronary catheterization, leading to cardiac revas- cularization in 1 patient. Of 2 patients (1.7%) who suffered a postoperative myocardial infarction, 1 patient had a fixed perfusion defect and 1 was found to have a two-vessel disease on coronary catheterization. There were no perioperative deaths. In the follow- up period (15.9 months; range one to sixty), no cardiac deaths occurred. With this treatment algorithm using selective dipyridamole-thallium scan evaluation, perioperative and long-term cardiac morbidity and mortality can be minimized.

A prospective, blinded assessment of the value of quantitative dipyridamole-thallium scanning in the prediction of perioperative myocardial infarction following peripheral vascular surgery

A prospective, blinded assessment of the value of quantitative dipyridamole-thallium scanning in the prediction of perioperative myocardial infarction following peripheral vascular surgery

The Role of Coronary Angiography and Coronary Revascularization Before Noncardiac Vascular Surgery

Objective. —To determine whether preoperative coronary angiography and revascularization improve short-term outcomes in patients undergoing noncardiac vascular surgery. Design. —Decision analysis. Patients. —Patients undergoing elective vascular surgery who had either no angina or mild angina and a positive dipyridamole-thallium scan result. Interventions. —Three strategies were compared. The first strategy was to proceed directly to vascular surgery. The second was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to cancel vascular surgery in patients with severe inoperable coronary artery disease (CAD). The third was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to perform vascular surgery in patients with inoperable CAD. Main Outcome Measures. —Mortality, nonfatal myocardial infarction, stroke, uncorrected vascular disease, and cost. All outcomes were assessed within 3 months. Results. —Proceeding directly to vascular surgery led to lower morbidity and cost in the base case analysis. The coronary angiography strategy led to higher mortality if vascular surgery would proceed in patients with inoperable CAD, but led to slightly lower mortality if vascular surgery were canceled in patients with inoperable CAD. The coronary angiography strategy also led to lower mortality when vascular surgery was particularly risky. Conclusions. —Decision analysis indicates vascular surgery without preoperative coronary angiography generally leads to better outcomes. Preoperative coronary angiography should be reserved for patients whose estimated mortality from vascular surgery is substantially higher than average. ( JAMA . 1995;273:1919-1925)

Routine Perioperative Dipyridamole 2O1TI Imaging in Diabetic Patients Undergoing Vascular Surgery: Is it necessary?

To assess the utility of dipyridamole thallium testing in symptomatic and asymptomatic patients with diabetes undergoing vascular surgery. Dipyridamole 201Tl myocardial scintigraphy was performed preoperatively in 93 consecutive patients with diabetes undergoing peripheral vascular procedures. The utility of clinical and thallium variables in predicting cardiovascular complications was assessed. Two groups of patients were identified: group A (36 patients) without clinical evidence of cardiac disease and group B (57 patients) with clinical evidence of cardiac disease. Dipyridamole thallium scans were abnormal in 21 of 36 (58%) of group A patients compared with 53 of 57 (93%) of group B patients (P < 0.0001). Compared with group B patients with perfusion defects, group A patients with perfusion abnormalities tended to have fewer defects per scan (2.7 +/- 1.5 vs. 3.6 +/- 1.9, P = 0.05). No perioperative cardiac complications occurred in group A patients while perioperative cardiac complications occurred in 9 of 57 (16%, 95% CI 7-28%) group B patients (P = 0.01). For the entire study population, the complication rate was 10%. Diabetic individuals without clinical markers for coronary artery disease appear to be at low risk for adverse postoperative cardiac events after vascular surgery. Preoperative myocardial perfusion imaging may add little to cardiovascular risk assessment in this subgroup of patients with diabetes.

Prediction of in‐hospital cardiac events using dipyridamole‐thallium scintigraphy performed very early after acute myocardial infarction

Ischemic complications occur frequently during hospitalization after acute myocardial infarction. Dipyridamole-thallium scintigraphy performed early after admission can detect residual ischemia, may have additional prognostic value and be useful in the management of these patients. Dipyridamole infusion and 201thallium imaging were performed on the third day of infarction in 114 consecutive patients. Coronary angiography was performed before hospital discharge in 90% of patients and exercise testing was performed at the time of discharge in patients without contraindications. Side effects occurred in 28 patients, but they were mild and transient or rapidly reversed with intravenous aminophylline. During hospitalization, three patients died and four had a nonfatal reinfarction. Patients with these major cardiac events had previously shown a higher prevalence of reversible perfusion defects during testing (71 vs. 31%, p < 0.05). In addition, 19 patients had early recurrent ischemia requiring early in-hospital revascularization. Overall, cardiac events defined as death, reinfarction, or early myocardial revascularization occurred in 22 patients. Of the patients with these events, 68% had thallium redistribution on initial myocardial scanning compared with 25% of patients without events (p = 0.0001). Patients with cardiac events also showed a higher number of myocardial segments with reversible perfusion defects (1.8 +/- 2.2 vs. 0.6 +/- 1.3, p = 0.001). Logistic regression analysis revealed that among all the other clinical, scintigraphic, and angiographic variables, the presence of thallium redistribution on the dipyridamole-thallium scan was the only independent predictor of cardiac events, increasing the risk by sixfold. Furthermore, during a 1-year follow-up, 14 other patients had ischemic events. Of these, 64% had previously shown thallium redistribution during early dipyridamole testing compared with 19% of patients without cardiac events (p < 0.001). Intravenous dipyridamole-thallium-scintigraphy performed very early after myocardial infarction is safe and useful to predict in-hospital ischemic events.

The role of coronary angiography and coronary revascularization before noncardiac vascular surgery

<h3>Objective.</h3> —To determine whether preoperative coronary angiography and revascularization improve short-term outcomes in patients undergoing noncardiac vascular surgery. <h3>Design.</h3> —Decision analysis. <h3>Patients.</h3> —Patients undergoing elective vascular surgery who had either no angina or mild angina and a positive dipyridamole-thallium scan result. <h3>Interventions.</h3> —Three strategies were compared. The first strategy was to proceed directly to vascular surgery. The second was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to cancel vascular surgery in patients with severe inoperable coronary artery disease (CAD). The third was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to perform vascular surgery in patients with inoperable CAD. <h3>Main Outcome Measures.</h3> —Mortality, nonfatal myocardial infarction, stroke, uncorrected vascular disease, and cost. All outcomes were assessed within 3 months. <h3>Results.</h3> —Proceeding directly to vascular surgery led to lower morbidity and cost in the base case analysis. The coronary angiography strategy led to higher mortality if vascular surgery would proceed in patients with inoperable CAD, but led to slightly lower mortality if vascular surgery were canceled in patients with inoperable CAD. The coronary angiography strategy also led to lower mortality when vascular surgery was particularly risky. <h3>Conclusions.</h3> —Decision analysis indicates vascular surgery without preoperative coronary angiography generally leads to better outcomes. Preoperative coronary angiography should be reserved for patients whose estimated mortality from vascular surgery is substantially higher than average. (<i>JAMA</i>. 1995;273:1919-1925)

The Role of Coronary Angiography and Coronary Revascularization Before Noncardiac Vascular Surgery

To determine whether preoperative coronary angiography and revascularization improve short-term outcomes in patients undergoing noncardiac vascular surgery. Decision analysis. Patients undergoing elective vascular surgery who had either no angina or mild angina and a positive dipyridamole-thallium scan result. Three strategies were compared. The first strategy was to proceed directly to vascular surgery. The second was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to cancel vascular surgery in patients with severe inoperable coronary artery disease (CAD). The third was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to perform vascular surgery in patients with inoperable CAD. Mortality, nonfatal myocardial infarction, stroke, uncorrected vascular disease, and cost. All outcomes were assessed within 3 months. Proceeding directly to vascular surgery led to lower morbidity and cost in the base case analysis. The coronary angiography strategy led to higher mortality if vascular surgery would proceed in patients with inoperable CAD, but led to slightly lower mortality if vascular surgery were canceled in patients with inoperable CAD. The coronary angiography strategy also led to lower mortality when vascular surgery was particularly risky. Decision analysis indicates vascular surgery without preoperative coronary angiography generally leads to better outcomes. Preoperative coronary angiography should be reserved for patients whose estimated mortality from vascular surgery is substantially higher than average.

Combined coronary artery bypass grafting and abdominal aortic aneurysm repair.

Fifteen patients of mean age 65 years underwent simultaneous coronary artery bypass grafting and abdominal aortic aneurysm repair between 1988 and 1992. Of these 13 had coexistent angina and two had symptomless coronary artery disease detected by preoperative dipyridamole thallium scanning or exercise stress testing. All patients had significant coronary artery disease on coronary angiography. Coronary artery bypass grafting was performed first, with a median number of grafts of 4, a median aortic cross-clamp time of 39 min and a median bypass time of 74 min. Abdominal aortic aneurysm repair followed with a median aortic clamp time of 66 min. Six straight and nine bifurcated grafts were inserted. The median total operating time was 395 min. All patients were managed postoperatively in the cardiothoracic intensive care unit with a median duration of 5 days. The median total hospitalization was 14 days. One patient died of non-cardiac causes; hence the mortality rate was 6.7%. The authors' experience suggests that combined coronary artery bypass grafting and abdominal aortic aneurysm repair is feasible in carefully selected patients.

Con: Pulmonary artery catheters are not routinely indicated in patients undergoing elective abdominal aortic reconstruction

Con: Pulmonary artery catheters are not routinely indicated in patients undergoing elective abdominal aortic reconstruction

Prophylactic Myocardial Revascularization Based on Dipyridamole-Thallium Scanning before Peripheral Vascular Surgery

Cardiac events continue to be the leading cause of perioperative mortality following peripheral vascular reconstruction. The role of preoperative cardiac screening and prophylactic myocardial revascularization in patients without clinical evidence of coronary artery disease is undefined. Fifteen patients with no clinical evidence of coronary artery disease who were found to have reversible defects on dipyridamole-thallium scans and severe correctable coronary artery disease underwent aortocoronary artery bypass grafting. There was one (6.7%) operative death. Three patients (20%) developed postoperative complications: two atrial fibrillation and one breakdown of the saphenous vein harvest site. Thirteen patients underwent subsequent peripheral vascular surgery: seven had abdominal aortic procedures, three infrainguinal reconstruction, two carotid endarterectomy and one carotid-subclavian artery bypass. There were no perioperative or late deaths, cardiac complication, electrocardiographic changes, or episodes of angina associated with the peripheral vascular procedures. Thus, dipyridamole-thallium imaging appears to help select a group of symptom-free, but high cardiac risk, vascular patients in whom preparatory myocardial revascularization and subsequent peripheral vascular surgery can be performed with acceptable mortality and morbidity. The life expectancy of these patients may be improved and, specifically, the risk of their subsequent vascular surgery may be reduced by this approach.

Combined Myocardial and Peripheral Revascularization of the Lower Limbs

In a series of 2,786 patients submitted to operation for peripheral arterial disease of the lower limbs from 1964 to 1986, the overall mortality rate was 6.9%, and 69% of these died of acute myocardial infarction (AMI). In order to reduce the incidence of AMI, from 1979 to 1990, 258 patients with lower limb ischemia were investigated for coronary artery disease (CAD). All of them had clinical signs of myocardial ischemia and were submitted to coronary arteriog raphy after previous evaluation with dipyridamole thallium scanning and echo cardiography. Severe CAD was shown in 137 patients, and combined myocardial and peripheral revascularization was planned: coronary artery by pass grafting (CABG) was performed first on 61 patients followed by peripheral operation after an average of three weeks; simultaneous procedure was per formed on 76 patients upon intraoperative decision. The overall mortality rate was 3.6%: 3.3% for staged and 3.9% for simultaneous procedure. No myocar dial infarction was registered in the early postoperative period, but peripheral graft occlusion in 5.8% (8/137) was the main complication. The actuarial five- year survival rate was 87%; the actuarial five-year patency of the peripheral grafts was 61.9%. The authors conclude that combined myocardial and peripheral revascular ization prevents early death from myocardial infarction and improves late sur vival without increasing surgical risks; with proper judgment simultaneous operations can be performed.

An assessment of the positive predictive value of abnormal dipyridamole thallium scanning in vascular surgery patients: John D. L. Bry, MD, Michael Belkin, MD, Thomas F. O'Donnell, MD, William C. Mackey, MD, and James E. Udelson, MD, New England Medical Center Hospitals, Boston, Mass.

An assessment of the positive predictive value of abnormal dipyridamole thallium scanning in vascular surgery patients: John D. L. Bry, MD, Michael Belkin, MD, Thomas F. O'Donnell, MD, William C. Mackey, MD, and James E. Udelson, MD, New England Medical Center Hospitals, Boston, Mass.

Usefulness of dipyridamole-thallium scanning for preoperative evaluation of cardiac risk for nonvascular surgery : Coley CM, Field TS, Abraham SA, et al; Am J Cardiol 69: 1280–1285, 1992

Usefulness of dipyridamole-thallium scanning for preoperative evaluation of cardiac risk for nonvascular surgery : Coley CM, Field TS, Abraham SA, et al; Am J Cardiol 69: 1280–1285, 1992