Dipyridamole thallium scanning in the evaluation of coronary artery disease in elective abdominal aortic surgery.

Dipyridamole thallium scanning was routinely performed on 68 consecutive patients who presented for elective aortic surgery. All 68 patients were judged by clinical assessment to be at low risk for perioperative cardiac complications. In addition, 42 of 68 patients had a history of myocardial infarction, stable angina, or abnormal echocardiographic findings (group 1). Twenty-six of 68 patients did not have a history of myocardial infarction, angina, or abnormal echocardiographic findings (group 2). In group 1, 34 of 4 patients had positive results on dipyridamole thallium scanning, and 15 of these patients were found to have critical coronary artery disease on subsequent cardiac catheterization; nine underwent immediate coronary artery bypass grafting, and six had their coronary artery disease treated medically and their vascular operations cancelled. The remaining 27 patients in group 1 underwent elective operations, with six (22%) of 27 sustaining postoperative cardiac complications. None of the group 2 patients was found to have critical coronary artery disease. All patients in group 2 underwent aortic operation without cardiac complication. Routine dipyridamole thallium scanning detected a 22% (15 of 68) incidence of critical coronary artery disease overall. There was a 36% (15 of 42) incidence of critical coronary artery disease in group 1 patients vs 0% in group 2 patients (95% confidence interval, 21% to 50%). We conclude that the use of dipyridamole thallium scanning in low-risk patients for cardiac screening prior to elective aortic operations is beneficial in selected patients who have a history of myocardial infarction, angina, or abnormal echocardiographic findings, but is not necessary in patients with no history of coronary artery disease.     

Association of atherosclerotic coronary artery disease and pulse pressure with renal disease progression

BACKGROUND: This study was performed to identify the association of atherosclerotic coronary artery disease (CAD) and pulse pressure with renal disease progression in patients with mild chronic renal disease. METHODS: Eligibility criteria for enrollment in this study included age 18 to 70 years, mild chronic renal disease (CRD), undergoing thallium SPECT and echocardiography and followed longer than three years. Mild CRD was defined as serum creatinine level of 1.5 to 3.0 mg/dL in men and 1.4 to 3.0 mg/dL in women. Patients with serious illness, history of kidney transplantation, ejection fraction less than 40% on echocardiography and development of acute renal failure during follow-up were excluded. RESULTS: A total of 87 patients were included in this study. The underlying renal disease included diabetic nephropathy in 51 patients. Forty-five patients showed positive findings on thallium SPECT and they were classified as having CAD. Coronary angiography showed significant stenosis in 41 of 42 patients studied. Median duration of follow-up was 56 months. During the follow-up period, 40 patients required chronic dialysis therapy and 16 patients showed a doubling of baseline serum creatinine in three years. These 56 patients were classified as progressors. Comparison of clinical and laboratory parameters between progressors and nonprogressors showed a difference in the presence of diabetic nephropathy, mean arterial pressure, 24-h urine protein (p < 0.001), pulse pressure (p < 0.01), total cholesterol and presence of CAD (p < 0.05). There was no association between the progression of CRD and the results of CAD or treatment of CAD. Multivariate logistic regression analysis showed that the presence of diabetic nephropathy and mean arterial pressure > 100 mm Hg were independent predictors of CRD progression. CONCLUSION: Atherosclerotic coronary artery disease and pulse pressure were associated with renal disease progression.     

Predicting cardiac events with Tl201 dipyridamole myocardial scintigraphy in renal transplant recipients

BACKGROUND: Renal transplant recipients should be screened for coronary artery disease. The purpose of this study was to evaluate the usefulness of thallium-201 dipyridamole myocardial perfusion single-photon emission computed tomography (SPECT) to predict major cardiac events in these patients. METHODS AND RESULTS: Eighty-two consecutive patients (61 males) in hemodialysis (HD) treatment, awaiting renal transplantation, underwent dipyridamole Tl-201 SPECT for pretransplant risk stratification. SPECT semiquantitative analysis showed a normal perfusion pattern in 52 patients (group A) and fixed defects in 9 (group B). Reversible perfusion defects were found in 21 (group C). Cardiac death, myocadial infarction, and unstable angina were sought as cardiac events. During a follow-up lasting 28.3 +/- 21.6 months, three patients of group A died for a non-cardiac cause. In group C, six patients (28.6%) had a cadiac event: one had a non-q wave myocardial infarction after renal transplantation; five were admitted with unstable angina. No cardiac events were observed in groups A and B (p = 0.0001). SPECT semiquantitative analysis showed that a summed difference score > or = 3 significantly increased the risk of cardiac events (odds ratio 4.5, C.I. 2.5-8.1). CONCLUSION: Cardiac events were only observed in HD patients with Tl-201 SPECT dipyridamole reversible defects (group C). A normal pattern or a fixed defect in Tl-201 dipyridamole SPECT in HD patients identified a good long-term prognosis.     

Myocardial scintigraphy using a fatty acid analogue detects coronary artery disease in hemodialysis patients

BACKGROUND: Coronary artery disease contributes significantly to mortality in end-stage renal disease (ESRD) patients. Single-photon emission computed tomography (SPECT) using an iodinated fatty acid analogue, iodine-123-methyl iodophenylpentadecanoic acid (123I-BMIPP), can assess fatty acid metabolism in the myocardium. We investigated the ability of 123I-BMIPP SPECT to detect coronary artery disease in hemodialysis patients compared with 201thallium chloride (201Tl) SPECT. METHODS: We prospectively studied 130 ESRD patients undergoing hemodialysis for a mean of 88.6 months (male/female, 77/53; mean age, 63.8 years). Dual SPECT using 123I-BMIPP and 201Tl was performed, followed by coronary angiography. SPECT findings were graded in 17 segments on a five-point scale (0, normal uptake; 4, none) and assessed as a summed score. RESULTS: By coronary angiography, 71.5% of patients (93/130) had significant coronary stenosis (> or =75%), and five patients showed coronary spasm without coronary stenosis. When a BMIPP summed score of 6 or more was defined as abnormal, sensitivity, specificity, and accuracy for detecting coronary artery disease by BMIPP SPECT were 98.0%, 65.6%, and 90.0%, respectively; in contrast, these parameters for detecting coronary artery disease by Tl SPECT were 84.7%, 46.9%, and 75.0%, respectively, when a Tl summed score of 1 or more was defined as abnormal. In receiver operating characteristic analysis, the area under the curve was 0.895 in BMIPP and 0.727 in Tl SPECT, respectively. CONCLUSION: Resting BMIPP SPECT is superior to Tl SPECT for detecting coronary lesions, and provides safe screening for coronary artery disease among maintenance hemodialysis patients.     

Myocardial perfusion imaging is an effective screening test for coronary artery disease in liver transplant candidates

A reliable screening test for coronary artery disease (CAD) in liver transplant (LT) candidates with end‐stage liver disease is essential because a high percentage of perioperative mortality and morbidity is CAD‐related. In this study, the effectiveness of myocardial perfusion imaging (MPI) for identification of significant CAD in LT candidates was evaluated. Records of 244 patients meeting criteria for MPI were evaluated: 74 met inclusion criteria; 40 had a positive MPI and cardiology follow‐up; 27 had a negative MPI and underwent LT; and seven had a negative MPI and then had coronary angiography or a significant cardiac event. A selective MPI interpretation strategy was established where MPI‐positive patients were divided into high, intermediate, and low CAD risk groups. The overall incidence of CAD in this study population was 5.1% and our strategy resulted in PPV 20%, NPV 94%, sensitivity 80%, and specificity 50% for categorizing CAD risk. When applied only to the subset of patients categorized as high CAD risk, the strategy was more effective, with PPV 67%, NPV 97%, sensitivity 80%, and specificity 94%. We determined that renal dysfunction was an independent predictive factor for CAD (p < 0.0001, odds ratio = 8.1), and grades of coronary occlusion correlated significantly with chronic renal dysfunction (p = 0.0079).     

Selection of patients for cardiac evaluation before peripheral vascular operations

Purpose: This study evaluated the value of preoperative cardiac screening with dipyridamole thallium scintigraphy and radionuclide ventriculography in vascular surgery patients.Methods: From July 1, 1989, to Dec. 31, 1991, we routinely (irrespective of the patient's cardiac history or symptomatology) performed dipyridamole thallium scintigraphy (DTS) and radionuclide ventriculography (RVG) in 394 patients being considered for an elective vascular operation. Patients with reversible defects on DTS underwent coronary arteriography.Results: DTS results were normal in 146 patients (37%), showed a fixed defect in 75 (19%), and showed a reversible defect in 173 (44%). Patients with and without a history of angina or myocardial infarction had identical rates of reversible defects. Normal left ventricular function (>50%) was noted in 76% of the patients; 17% had moderate dysfunction (35% to 50%) and 7% had a low ejection fraction (<35%). The finding of severe coronary artery disease led to cardiac revascularization in 17 patients who had no prior history of cardiac disease and in 13 patients with a history of angina or myocardial infarction. Two deaths and nine major complications were associated with coronary arteriography and cardiac revascularization. Vascular procedures (144 aortic, 53 carotid, 146 infrainguinal) were ultimately performed in 343 patients, with a mortality rate of 1.7% (3.5% aortic, 0% carotid, and 0.7% infrainguinal bypass). The nonfatal perioperative myocardial infarction rate was 2.0%. We monitored all 394 patients for cardiovascular events, with a mean follow-up of 40 months. Patients who underwent cardiac revascularization had a 4-year survival rate of 75%, which was similar to those with a normal DTS. Late cardiac events were significantly more frequent in patients who had either a reversible DTS or RVG <35%.Conclusions: Routine cardiac screening of vascular surgery patients had similar impact on patients irrespective of their prior history or current symptoms suggesting coronary artery disease. Routine screening did not result in substantial benefit. Screening studies such as DTS or RVG may be most useful as part of an overall risk versus benefit assessment in patients without active symptoms of coronary artery disease who have less compelling indications for vascular intervention (claudication, moderate-sized aortic aneurysms, or asymptomatic carotid disease). (J Vasc Surg 1996;23:802-9.)     

Association of Atherosclerotic Coronary Artery Disease and Pulse Pressure with Renal Disease Progression

Background.?This study was performed to identify the association of atherosclerotic coronary artery disease (CAD) and pulse pressure with renal disease progression in patients with mild chronic renal disease. Methods.?Eligibility criteria for enrollment in this study included age 18 to 70 years, mild chronic renal disease (CRD), undergoing thallium SPECT and echocardiography and followed longer than three years. Mild CRD was defined as serum creatinine level of 1.5 to 3.0 mg/dL in men and 1.4 to 3.0 mg/dL in women. Patients with serious illness, history of kidney transplantation, ejection fraction less than 40% on echocardiography and development of acute renal failure during follow-up were excluded. Results.?A total of 87 patients were included in this study. The underlying renal disease included diabetic nephropathy in 51 patients. Forty-five patients showed positive findings on thallium SPECT and they were classified as having CAD. Coronary angiography showed significant stenosis in 41 of 42 patients studied. Median duration of follow-up was 56 months. During the follow-up period, 40 patients required chronic dialysis therapy and 16 patients showed a doubling of baseline serum creatinine in three years. These 56 patients were classified as progressors. Comparison of clinical and laboratory parameters between progressors and nonprogressors showed a difference in the presence of diabetic nephropathy, mean arterial pressure, 24-h urine protein (p<0.001), pulse pressure (p<0.01), total cholesterol and presence of CAD (p<0.05). There was no association between the progression of CRD and the results of CAD or treatment of CAD. Multivariate logistic regression analysis showed that the presence of diabetic nephropathy and mean arterial pressure ≥100 mm Hg were independent predictors of CRD progression. Conclusion.?Atherosclerotic coronary artery disease and pulse pressure were associated with renal disease progression.     

Comparison of left ventricular function and myocardial perfusion for evaluating perioperative cardiac risk of abdominal aortic surgery

The measurement of left ventricular function by gated blood pool scanning and of myocardial perfusion by dipyridamole thallium imaging were compared in a prospective study of patients who had abdominal aortic aneurysm or aortoiliac occlusive disease to determine which measurement was the better predictor of postoperative cardiac complications. Sixty-six men and 19 women (mean age 67 years) underwent both tests before admission for surgery. Fifty-six had repair of an abdominal aortic aneurysm, and 29 had reconstruction for aortoiliac occlusive disease. In 17 patients the left ventricular ejection fraction was less than 50%. Dipyridamole thallium imaging was positive, showing redistribution, in 45 patients. Postoperative cardiac complications occurred in 33 patients. The sensitivity of dipyridamole thallium imaging (91%) was significantly (p less than 0.01) greater than that observed with gated blood pool scanning (27%). However, the specificity of gated blood pool scanning (85%) was similar to that of dipyridamole thallium imaging (71%). Diagnostic accuracy was greatest with dipyridamole thallium imaging (79% versus 62% [p less than 0.02]). Dipyridamole thallium imaging is superior to gated blood pool scanning for perioperative evaluation of vascular surgical patients.     

Failure of negative dipyridamole thallium scans to predict perioperative myocardial ischaemia and infarction

Three cases of postoperative myocardial infarction are reported in patients with normal or fixed defects on preoperative dipyridamole thallium scans (interpreted as "negative" for active cardiac ischaemic risk). All patients were monitored with an ambulatory electrocardiographic recorder from the evening before surgery through the first two postoperative days. Two of the patients demonstrated preoperative or early postoperative ischaemia, suggesting that the test was a false negative. The third patient did not demonstrate ischaemia during the period of monitoring, but developed a myocardial infarction during the third postoperative day, suggesting progression of the underlying coronary artery disease. Preoperative dipyridamole thallium imaging may result in false negative scans in selected high-risk populations.     

Cardiac Findings in Asymptomatic Chronic Hemodialysis Patients with Persistently Elevated Cardiac Troponin I Levels

Background. The prevalence and significance of higher than normal cardiac troponin I (cTnI) levels in asymptomatic chronic hemodialysis (HD) patients remains a source of discussion. The aim of the present study was to evaluate the prevalence of higher than normal cTnI levels in asymptomatic HD patients, as determined by the last generation of immunoassay, and to perform further cardiological investigations in those patients with persistently elevated cTnI levels. Methods. All chronic HD patients in our center who had exhibited no symptoms of coronary artery disease (CAD) during the previous four weeks were screened. cTnI levels were determined before dialysis in all patients using the last generation AccuTnI? assay (UniCel DxI 800, Beckman Coulter). The cTnI levels of those patients with elevated cTnI at the screening evaluation were then measured monthly for six months. We were thus able to identify a group of patients with persistently elevated cTnI levels (> 3 consecutive months) who subsequently underwent cardiac echography and dipyridamole-exercise (D-E) thallium testing. If stress myocardial ischemia was detected, a coronary angiography was then performed. Results. Fifty patients (32 males) were included: mean age 62.8 ± 13.6 years, 20 (40%) with a history of CAD, and 21 (42%) diabetic. At the initial screening, the mean cTnI concentration was 0.05 ± 0.06 μg/L and the cTnI levels were higher than normal (> 0.09 μg/L) in six patients (12%). In the follow-up, the cTnI normalized immediately in two patients but remained persistently elevated (range, 0.10–0.48 μg/L) in four (8%). These four patients (all males, one diabetic) had a mean age of 70.2 ± 6.6 years, and all had heart failure with a history of severe CAD with previous myocardial infarction (n = 4), coronary stenting (n = 3), and/or bypass (n = 2). D-E thallium imaging showed reversible myocardial ischemia in all. The stress ischemia involved one to four cardiac segments and was slight to moderate in three patients and severe in the diabetic patient. A coronary angiogram was performed in all patients, and showed lesions of variable severity: severe three-vessel CAD with severe systolic dysfunction in two patients (including the diabetic), and non-critical/peripheral coronary stenosis in the other two. Conclusions. Among the asymptomatic HD patients in our center, we identified four (8%) with persistently elevated cTnI levels, as determined using the last generation AccuTnI? assay. All of them had a history of severe CAD with heart failure and exhibited reversible myocardial ischemia upon D-E thallium imaging; coronary angiography revealed coronary lesions of variable severity. Overall, our data indicate that persistent low-grade cTnI elevation occurs in HD patients having longstanding severe cardiac disease, but, from our data, it is difficult to reach a conclusion as to the best clinical approach for this group of patients.     

Cardiac assessment with thallium scanning prior to aortic aneurysm repair.

Coronary artery disease occurs commonly in patients with aortic aneurysms and is a major cause of morbidity and mortality. The role of screening and intervention for cardiac disease prior to aneurysm repair is controversial. The outcome after cardiac screening with thallium scanning and/or angiography in 102 consecutive patients undergoing aortic aneurysm repair was documented. Significant coronary artery disease was found in 34 (33%) patients and two patients had either coronary artery bypass or angioplasty prior to aneurysm repair. There was no cardiac mortality after aneurysm repair and the overall mortality on an intention-to-treat basis was 2%. There was good correlation between prior history of cardiac events, electrocardiography (ECG) and the results of screening with thallium scanning and angiography. There was no correlation between cardiac history, ECG and the incidence of cardiac events in the postoperative period. Significant coronary artery disease was found in 33% of patients without a cardiac history or abnormal ECG. Cardiac screening with thallium scanning confirmed a high incidence of significant coronary disease in patients with aortic aneurysm. In this study, cardiac intervention followed by expedient aneurysm repair in 20 patients was associated with zero mortality. The short-term benefit of such a policy is difficult to prove and its main advantage may be better long-term survival.     

Prognostic Value of Cardiovascular Screening in Potential Renal Transplant Recipients: A Single-Center Prospective Observational Study

We assessed the outcome of pretransplant cardiac assessment in a single center. Three hundred patients with end-stage renal disease underwent electrocardiogram, Bruce exercise testing (ETT) and ventricular assessment by cardiac MRI. Patients with high index of suspicion of coronary artery disease (CAD) underwent coronary angiography and percutaneous coronary intervention (PCI) if indicated. Two hundred and twenty-two patients were accepted onto the renal transplant waiting list; 80 patients were transplanted during the follow-up period and 60 died (7 following transplantation). Successful transplantation was associated with improved survival (mean survival 4.5 ± 0.6 years vs. listed not transplanted 4.1 ± 1.4 years vs. not listed 3.1 ± 1.7 years; p < 0.001). Ninety-nine patients underwent coronary angiography; 65 had normal or low-grade CAD and 34 obstructive CAD. Seventeen patients (5.6%) were treated by PCI. There was no apparent survival difference between patients who underwent PCI or coronary artery bypass graft compared to those who underwent angiography without intervention or no angiography (p = 0.67). Factors associated with nonlisting for renal transplantation included burden of preexisting cardiovascular disease, poor exercise tolerance and severity of CAD. Pretransplant cardiovascular screening provides prognostic information and information that can be used to restrict access to transplantation. However, if the aim is to identify and treat CAD, the benefits are far from clear.     

Prognostic value of stress myocardial perfusion imaging using adenosine triphosphate at the beginning of haemodialysis treatment in patients with end-stage renal disease

Background. Non-invasive detection of coronary artery disease(CAD) remains difficult in patients with end-stage renal disease(ESRD). This study evaluated the ability of pharmacologic stressmyocardial perfusion imaging to predict cardiac events in patientswith ESRD. Methods. A prospective study was carried out in 49 consecutivepatients with ESRD. Thallium-201 single photon emission computedtomography (SPECT) using high-dose adenosine triphosphate (ATP)was performed within 1 month of the beginning of haemodialysis.The study end-point was a cardiac event or the 1-year anniversaryof the SPECT study. Results. Twenty-four patients (17 diabetics, 57% and seven non-diabetics,37%) had myocardial perfusion defects. The remaining 25 patientshad normal perfusion images. Fifteen patients had non-fatalcardiac events and two patients died of a cardiac cause. Allpatients who had non-fatal cardiac events underwent myocardialrevascularization and survived until the end of follow-up. The1-year cardiac event-free survival rate was 34% among patientswith perfusion defects and 96% among patients without perfusiondefects (P<0.001). The presence of a myocardial perfusiondefect was the only independent predictor of 1-year cardiacevents both in overall (HR, 49.91; 95% CI, 5.15–484.00;P<0.001) and in diabetic patients (HR, 33.72; 95% CI, 2.96–383.5;P = 0.005). Diabetes and an increased C-reactive protein wereassociated with the progression of CAD. Conclusions. Normal myocardial perfusion imaging by stress thallium-201SPECT using high-dose ATP performed within 1 month after thebeginning of haemodialysis treatment is a powerful predictorof cardiac event-free survival in patients with ESRD.     

Prevalence of coronary artery disease using thallium-201 single photon emission computed tomography among patients newly undergoing chronic peritoneal dialysis and its association with mortality

BACKGROUND: Previous data about the prevalence of coronary artery disease in dialysis patients were mainly based on history or electrocardiogram. METHODS: We evaluated the prevalence of coronary artery disease using routine thallium-201 single photon emission computed tomography (SPECT) in 227 patients at the start of chronic peritoneal dialysis between January 1996 and October 2003. We also analyzed its association with mortality. RESULTS: Fifty-one patients (22.5%) were positive on thallium SPECT. There were significant differences in age, underlying diabetic nephropathy, and C-reactive protein (CRP), serum albumin, total cholesterol, and prealbumin levels among patients positive and negative on thallium SPECT. Multivariate logistic regression analysis showed that age (> or =60 years), underlying diabetic nephropathy, and CRP (> or =0.5 mg/dl) were independent predictors of positive thallium SPECT, with the patients positive for all three factors having a probability for positive thallium SPECT of 43%, whereas patients negative for all three factors had a probability of only 4%. Ninety patients died, and 137 survived during the median follow-up period of 34 (range 3-99) months. Kaplan-Meier survival analysis revealed that age, underlying diabetic nephropathy, serum albumin, prealbumin, and CRP levels, positive thallium SPECT, and smoking affected survival. Survival was not different according to gender, presence of hypertension, body mass index, total cholesterol, or lipoprotein(a). Cox regression analysis showed that only underlying diabetic nephropathy and age (> or =60 years) were independent predictors of mortality. CONCLUSIONS: We found that 22.5% of the patients who started chronic peritoneal dialysis had a positive thallium SPECT. Age, underlying diabetic nephropathy, and CRP were independent predictors of a positive thallium SPECT. Underlying diabetic nephropathy and age, but not positive thallium SPECT, were independent predictors of mortality.     

The impact of left ventricular systolic dysfunction on survival after renal transplantation

BACKGROUND: Gated single photon emission computed tomography (SPECT) provides information on myocardial perfusion and left ventricular ejection fraction (LVEF), which correlates with risk of cardiac events in patients with known or suspected coronary artery disease (CAD). We hypothesize that decreased LVEF at time of renal transplant evaluation is an independent risk factor for cardiac death and nonfatal events after transplant. METHODS AND RESULTS: A total of 653 recipients of renal allografts between 1998 and 2005 had stress SPECT imaging before transplantation. One hundred and nineteen (18%) patients had left ventricular (LV) systolic dysfunction (LVEF 相似文献   

Detecting asymptomatic coronary artery disease using routine exercise testing and exercise thallium scintigraphy in patients with atherosclerotic vascular disease

ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored exercise testing may enhance sensitivity and specificity of non-invasive evaluation. Thirty-two patients were subjected to ECG-monitored exercise testing, exercise thallium scintigraphy and coronary angiography. The sensitivity of ECG-monitored exercise testing for detecting coronary artery disease was calculated at 81.8% and the specificity at 87.5%, while the figures for exercise thallium scintigraphy were 73.1% and 33.3% respectively. Using these two methods in combination yielded a predictive accuracy of 90.6%. The only advantage of exercise thallium scintigraphy over exercise ECG appears to be in patients in whom the latter test could not be interpreted or was non-diagnostic.     

Value of thallium myocardial imaging in the prediction of future cardiovascular events in patients with end-stage renal failure

Chronic renal failure is associated with an increased rate ofpremature death from cardiovascular disease. Non-invasive identificationof asymptomatic cardiac disease should be valuable in the managementof such patients, and in selection for transplantation. Onehundred and three high-risk patients (66 male, 37 female) withchronic renal failure who were without cardiovascular symptomswere assessed by exercise-graded thallium myocardial perfusionimaging and followed prospectively for 4 years. The developmentof a cardiovascular event, or death, and the interval to eventor death were recorded. Cardiovascular events were documented in 50 patients; in 44of the 60 patients with a positive thallium test and in onlysix of the 43 patients with a negative thallium test (test sensitivity88%, specificity 70%, predictive value of a positive test 73%).Forty patients died, 28 from cardiovascular causes, during thestudy period. Thallium myocardial perfusion imaging is of value in the predictionof future cardiovascular events in patients with chronic renalfailure, and is a useful non-invasive screening technique inpatients with end-stage renal failure being considered for transplantation.     

Technetium myocardial perfusion scanning in prerenal transplant evaluation in the United kingdom

Because death with a functioning graft remains one of the most important causes of long-term renal transplant failure, cardiac risk stratification and screening for coronary artery disease are essential components of pretransplant assessment. Pretransplant screening for occult coronary artery disease in a subset of these patients may improve outcome. The UK follows the European Best practice guideline 1.5.5 E. Although echocardiography, thallium myocardial perfusion scanning (MPS), dobutamine stress echocardiography, and coronary angiography have been suggested as means of cardiovascular assessment, the best means of assessment remains undetermined. Therefore, we investigated the role of 99m technetium sestamibi myocardial perfusion scanning as an assessment tool for identifying those patients with end-stage renal failure at high risk of cardiovascular death after renal transplantation. Retrospectively, we studied 126 patients that had a MPS as part of their pretransplant assessment. Overall unadjusted survival was 65% at 3 years. Twelve deaths resulted from cardiovascular causes. A reversible defect on MPS was associated with a fatal cardiac event and all-cause mortality. The unadjusted hazard ratio of cardiac event with reversible defect on MPS was 3.1 (95% confidence interval, 1.1 to 18.2) and hazard ratio of death with reversible defect on MPS was 1.92 (95% confidence interval, 1.1 to 4.4). Thus, MPS may be a useful tool in cardiac risk stratification and in selecting patients with a favorable outcome after renal transplantation. Our patients with a reversible defect in particular have increased cardiac mortality. This group may benefit from coronary angiography.     

Detection and management of concomitant coronary artery disease in patients undergoing thoracic aortic surgery

OBJECTIVES: No method has been established to detect and manage coronary artery disease in patients undergoing thoracic aortic surgery. METHODS: Subjects were 192 patients scheduled for elective thoracic aortic surgery. Selection criteria for coronary angiography included a history of coronary artery disease or a positive dipyridamole myocardial perfusion imaging test. RESULTS: Four patients were inoperable due to complications associated with coronary angiography or aneurysm rupture following coronary revascularization. A total of 55 patients with coronary angiography (group A) underwent 57 thoracic aortic operations and 133 patients without coronary angiography (group B) underwent 143 similar operations. Of 13 group A patients with significant coronary stenosis, 9 underwent either preoperative percutaneous transluminal coronary angioplasty (n = 3) or concomitant coronary artery bypass (n = 6). Perioperative myocardial infarction occurred in 3 group A patients (5%) and in 4 group B patients (1%, ns). The incidence of cardiac events--perioperative myocardial infarction or cardiac death--in group A (11%, 6/57) was higher than that in group B (3%, 4/143; p < 0.05). Multivariate analysis demonstrated incomplete revascularization of major coronary arteries with significant stenosis as a risk factor for cardiac events (p = 0.0106). CONCLUSIONS: Although dipyridamole myocardial perfusion imaging was useful, additional selection criteria for coronary angiography is needed. Complete revascularization of major coronary arteries with significant stenosis is essential to reduce postoperative cardiac events.     

Use of digital subtraction fluorography in screening for coronary artery disease in patients with chronic renal failure

The diagnosis of coronary artery disease remains a major problem in patients with end-stage renal disease. Screening with conventional noninvasive techniques is limited by the poor exercise capacity of these patients. This study evaluated the accuracy of digital subtraction fluorography in detecting coronary calcification as a noninvasive, nonexercise screening test for coronary artery disease. Eighty-six patients under evaluation for renal transplantation and considered at increased risk of coronary artery disease were studied by coronary arteriography and digital subtraction fluorography for coronary calcification. Significant coronary disease (greater than or equal to 50% obstruction in at least one vessel) was present in 36 (42%) patients. The detection of coronary calcification by digital subtraction fluorography had a sensitivity of 78% and a specificity of 66%. The probability of disease being present in the absence of coronary calcification in this group was 18%. The detection of coronary calcification by digital subtraction fluorography appears to be a satisfactory and inexpensive screening test in this setting.