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T M Bateman

Publications and source records attributed to T M Bateman.

At least 19 recordsLinked to original sources
PubMed2001

Evidence-based risk assessment in noninvasive imaging.

UNLABELLED: Assessment of important clinical and economic outcomes has become central to the evaluation of patient care. Outcome research is deeply rooted in epidemiology, including the use of multivariable, risk-adjusted regression analysis. In our current health care environment, these methods are increasingly being used to assess the quality of care and to profile physicians and laboratories. Nuclear medicine physicians therefore need to better understand outcome methodologies in order to evaluate patient outcomes, develop guidelines, and decide on patient management. METHODS: This review describes the methods of assessing the diagnostic and prognostic value of nuclear medicine techniques and, briefly, the methodologic limitations of sample size, frequency and type of events, and follow-up periods and the incremental value of imaging. Also described are logistic regression and Cox proportional hazards modeling. Models for risk assessment are designed to identify whether patients require conservative (i.e., low-risk) or aggressive (i.e., high-risk) treatment. Treatment selection is currently based on risk assessment and the formation of an integrated, empiric risk stratification algorithm of care. This review also includes the methods of assessing economic effectiveness and quality-of-life issues for patients examined with nuclear medicine techniques. CONCLUSION: In this era of constrained resources, low-cost outpatient-based care may be of increasing importance. High-quality evidence of the clinical and economic outcome of nuclear imaging is essential for helping health care providers and payers assess its value.

Cardiovascular Diseases↗
PubMed2000

Lipid risk factor correlates of ischemic heart disease as diagnosed by myocardial perfusion scintigraphy.

Patients with known coronary artery disease frequently change their lifestyles (e.g., diet, exercise, and smoking habit) after the diagnosis is made. Such changes can alter lipid risk factor levels and obscure etiologic risk factor associations with the presence of coronary artery disease. It is therefore preferable to determine the contribution of potential risk factors before the diagnosis of coronary artery disease has been established. In this trial, we used stress nuclear myocardial perfusion imaging to diagnose coronary artery disease in patients presenting for evaluation of chest pain. Two groups of age- and sex-matched patients were identified: a normal group (patients with no evidence of coronary artery disease), and an abnormal group (patients whose scans indicated the presence of significant coronary artery disease due to either fixed or reversible perfusion defects). Blood samples were drawn before scanning and analyzed for lipid risk factors. Compared to the normal group, the abnormal group had higher levels of triglycerides (189±91 vs. 135±51 mg/dL, p=0.003), lower levels of high-density lipoprotein cholesterol (39±9 vs. 45±14 mg/dL, p=0.037), and higher levels of small, dense low-density lipoprotein (LDL(3)) (42±18 vs. 32±13 mg/dL, p=0.007). Total cholesterol, low-density lipoprotein, and lipoprotein(a) levels were similar between groups. These findings suggest that ischemic heart disease, as assessed by myocardial perfusion scintigraphy, is more closely associated with the low high-density lipoprotein/high triglyceride syndrome than with increased low-density lipoprotein or total cholesterol levels. (c) 2000 by CHF, Inc.

Journal Article↗
PubMed1997

Bypass surgery versus coronary angioplasty for revascularization of treated diabetic patients.

BACKGROUND: The purpose of this study was to evaluate outcomes after coronary bypass surgery versus coronary angioplasty in 525 patients with pharmacologically treated diabetes. Diabetic patients constitute a significant portion of patients considered for coronary revascularization. Some studies have shown no difference in long-term outcome when comparing revascularization mode. Recently, the Bypass Angioplasty Revascularization Investigation reported better survival with bypass surgery over angioplasty in treated diabetic patients. However, the above studies have been limited by small cohorts of diabetic patients. METHODS AND RESULTS: By using a single-institution comprehensive database, a retrospective cohort design was used to study 525 consecutive pharmacologically treated diabetic patients who underwent coronary revascularization. Patients treated with surgery (n=246) were statistically similar when comparing age, gender, angina class, and ejection fraction to patients (n=279) treated with angioplasty. Follow-up was complete in 95% of bypass patients and 99% of angioplasty patients. Mean follow-up was 55.5 months. Complete revascularization was accomplished more often in the surgery group (79%) than in the angioplasty group (42%; P<.001). During a 6-year follow-up, repeat revascularization (8% versus 64%; P=.001), cardiac events (32% versus 41%; P=.04), and death (30% versus 37%; P=.08) occurred less in the bypass patients than the angioplasty patients. Multivariable analysis identified age >70 years, ejection fraction <40%, class IV angina, and incomplete revascularization, but not mode of revascularization, as correlates of late mortality. CONCLUSIONS: For most pharmacologically treated diabetic patients, freedom from death, myocardial infarction, and subsequent revascularization during long-term follow-up is superior with bypass surgery compared with angioplasty. This worse outcome was mediated in part by the frequent occurrence of incomplete revascularization with angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1996

Poloxamer-188 as an adjunct to primary percutaneous transluminal coronary angioplasty for acute myocardial infarction.

Poloxamer-188 is a surfactant polymer with antithrombotic and hemorheologic properties that make it potentially useful as an adjunct to acute reperfusion strategies. Animal studies and early human studies have documented poloxamer-188 to be effective at improving myocardial salvage when used as an adjunct to intravenous thrombolytic therapy for acute myocardial infarction. The current trial was a prospective pilot study involving 150 patients who were randomized in a 2:1 fashion to a poloxamer-188 infusion for 48-hours versus placebo. The poloxamer-188 infusion was well tolerated subjectively. The only clinically significant laboratory abnormality noted was an elevation in the serum creatinine above 2.0 g/dl in 12% (n = 12) of the 98 poloxamer-188 treated patients versus 1 of the 52 (2%) of the placebo treated patients (p = 0.048). Clinical end points including reinfarction (1% vs 4%), cardiogenic shock (7% vs 6%), and death (9% vs 4%) were statistically similar in the poloxamer-188 and placebo groups, respectively (p = NS). Using quantitative nuclear techniques, final infarct size and myocardial salvage were statistically similar in the poloxamer-188 and placebo groups. Mean left ventricular ejection fractions 1 week post after infarction were 51% +/- 12% in the poloxamer-188 group and 52% +/- 13% in the placebo group (p = NS). Final infarct size, was not altered by the poloxamer- 188 infusion; however, it was significantly correlated with normal perfusion (Thrombolysis in Myocardial Infarction grade 3 flow) in the infarct vessel after angioplasty. This study documented poloxamer-188 to be ineffective as an adjunct to primary angioplasty for acute myocardial infarction and resulted in azotemia in 12% of the patients.

Aged↗
PubMed1996

Incremental value of myocardial perfusion scintigraphy in prognosis and outcomes of patients with coronary artery disease.

The concept of incremental value in prognosis and outcome of patients with coronary artery disease is important to the field of noninvasive imaging. Because these tests are expensive, they should be held to the standard of demonstrating a statistical improvement over the information provided by clinical assessment and treadmill testing. Responding to the demand for cost-effective applications of myocardial perfusion scintigraphy, a large amount of research has recently been devoted to defining specific patient subsets in which incremental value exists for scintigraphy. Subsets thus far demonstrated to benefit incrementally include those men and women referred for possible coronary artery disease, with known coronary artery disease, and after percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, unstable angina, or recent infarction. Incremental cost savings also apply to these subsets except for patients with normal ECGs at rest and less than 15% likelihood for significant coronary artery disease.

Angioplasty, Balloon, Coronary↗
PubMed1996

The new paradigm for coronary artery disease: altering risk factors, atherosclerotic plaques, and clinical prognosis.

The old paradigm states that the greater the stenosis, the greater the risk of cardiac events. Revascularization procedures are the only effective approach to improving prognosis associated with coronary artery disease. In contrast, on the basis of the new paradigm, the nature of the plaque determines the risk of acute cardiovascular events. Dangerous plaques have a lipid-rich core with surrounding inflammation and a thin friable overlying fibrous cap, but they usually appear innocuous on angiography. Effective risk factor modification stabilizes the dangerous plaques and is associated with prompt improvement in endothelial dysfunction and a substantial decrease in the risk of acute cardiovascular events and death.

Adrenergic beta-Antagonists↗
PubMed1995

Comparison of stress echocardiography and stress myocardial perfusion scintigraphy for diagnosing coronary artery disease and assessing its severity.

The cumulative published literature dealing with the most frequently utilized noninvasive cardiac stress imaging modalities (radionuclide myocardial perfusion scintigraphy and echocardiography) was reviewed to gain insight on their comparative diagnostic accuracies. To be included, studies had to be performed in conjunction with exercise or a commonly used intravenous pharmacologic stress agent (dipyridamole, adenosine or dobutamine) and had to report temporally related coronary angiography findings. A total of > 75 studies were included, involving > 7,000 patients. Exercise single-photon emitted computed tomographic (SPECT) scintigraphy was more sensitive than exercise echocardiography for detecting coronary artery disease (CAD), localizing it to the proper coronary artery distribution and correctly identifying the presence of multivessel CAD. Adenosine, dipyridamole, and dobutamine provided similar diagnostic accuracy when performed in conjunction with SPECT scintigraphy, and all were more accurate than dobutamine echocardiography. Clinical specificity was similarly high with adenosine SPECT, dipyridamole echocardiography, and exercise echocardiography, and lower with exercise SPECT. Normalcy rate was high for exercise SPECT and similar to clinical specificity for echocardiography.

Coronary Disease↗
PubMed1995

Four- versus 6-minute infusion protocol for adenosine thallium-201 single photon emission computed tomography imaging.

Intravenous adenosine infusion results in immediate maximal coronary arteriolar vasodilatation. Side effects occur in most patients who receive adenosine. For these reasons, a shorter infusion for pharmacologic stress thallium-201 testing may improve patient tolerability without compromising diagnostic accuracy. In a retrospective, unblinded evaluation, we compared side effects and accuracy of a standard 6-minute adenosine infusion single photon emission computed tomography (SPECT) study with a 4-minute protocol in 730 and 621 patients, respectively. Adenosine was infused at 140 micrograms/kg/minute in both groups; thallium-201 was injected at the 3-minute mark of the 4-minute protocol and at the 4-minute mark of the 6-minute protocol. Angiographic follow-up (mean 8 days) after thallium-201 testing was available in 233 (32%) of the patients in the 6-minute protocol and in 174 (28%) of the patients in the 4-minute protocol (p not significant (NS). Side effects occurred in 90% of the patients in the 6-minute protocol and in 91% of the patients in the 4-minute protocol (p = NS). Premature termination of the infusion was required in 4% of the patients in the 6-minute protocol and 2% of the patients in the 4-minute protocol (p = 0.02). Second- or third-degree atrioventricular block was noted in 4.5% and 3.0% of the 6- and 4-minute groups, respectively (p = NS). The duration of symptoms averaged 2.9 +/- 4.4 minutes in the patients in the 6-min protocol and 2.1 +/- 1.6 minutes in the patients in the 4-minute protocol (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1994

Extended acquisition for minimizing attenuation artifact in SPECT cardiac perfusion imaging.

Artifacts due to attenuation can complicate the interpretation of SPECT cardiac perfusion images, especially when the attenuated region corresponds to that of a coronary vascular distribution. Since methods of correction are limited, some patients undergo coronary angiography unnecessarily. Acquisition using a three-detector camera provides more data that can serve to minimize the effects of localized attenuation if incorporated into the final reconstruction set. In this article, a practical approach for interpreting SPECT cardiac perfusion images is outlined, demonstrating with an illustrative case how this approach can be clinically helpful.

Artifacts↗
PubMed1993

Adenosine thallium-201 is superior to exercise thallium-201 for detecting coronary artery disease in patients with left bundle branch block.

OBJECTIVES: We sought to assess the comparative diagnostic accuracy of adenosine versus exercise in conjunction with thallium-201 scintigraphy for the detection and localization of coronary artery disease in patients with left bundle branch block on the rest electrocardiogram (ECG). BACKGROUND: Patients with left bundle branch block on the rest ECG frequently have artifactual reversible septal perfusion defects on exercise thallium-201 scintigraphy. Adenosine thallium scintigraphy is a theoretically attractive alternative in these patients. METHODS: One hundred seventy-three consecutive patients with left bundle branch block were evaluated with either exercise thallium (n = 56) or adenosine thallium (n = 117) scintigraphy. The tomographic thallium images were interpreted visually with adjunctive quantitative analysis. Follow-up cardiac catheterization was performed in 31 of the 56 patients in the exercise thallium group and 42 of the 117 patients in the adenosine thallium group. RESULTS: Minor subjective side effects were noted in most patients in the adenosine thallium group (86%); atrioventricular block occurred in seven patients (6%). The overall predictive accuracy was 93% in the adenosine thallium group and 68% in the exercise thallium group (p = 0.01). The combined specificity for the detection of disease in the coronary arteries subtending the septum (the left anterior descending and right coronary arteries) was only 42% with exercise thallium scintigraphy versus 82% with adenosine thallium scintigraphy (p < 0.0002). CONCLUSIONS: Adenosine thallium imaging 1) was superior to exercise thallium imaging in the detection of coronary artery disease in patients with left bundle branch block; 2) obviated septal artifacts, thereby markedly improving the specificity in the left anterior descending and right coronary arteries; and 3) was safe in patients with left bundle branch block.

Adenosine↗
PubMed1992

Safety and diagnostic accuracy of adenosine thallium-201 scintigraphy in patients unable to exercise and those with left bundle branch block.

Three hundred forty consecutive patients (mean age 69 +/- 9 years) were evaluated with adenosine tomographic thallium-201 scintigraphy for suspected coronary artery disease. Minor side effects occurred in 91% of patients. Out of 28 patients (8%) with potentially serious side effects, 28 had significant atrioventricular (AV) block (second-degree, 24 patients; third-degree, four patients; syncope occurred in two patients). Acute bronchospasm and severe refractory angina pectoris occurred in one patient each. All side effects were transient and without sequelae. One hundred twenty-one patients underwent coronary angiography within 9 days of adenosine thallium imaging. The predictive accuracies of adenosine thallium imaging for identifying and localizing ischemia to a specific coronary distribution were: left anterior descending = 88%, left circumflex = 84%, right coronary = 88%. The predictive accuracy of adenosine thallium imaging in patients with left bundle branch block was 91%, and was higher than the 71% predictive accuracy noted in 39 patients who underwent exercise thallium testing (p = 0.04). It is concluded that adenosine thallium-201 myocardial scintigraphy was (1) highly accurate for the detection and localization of significant coronary artery disease; (2) it was more accurate at detecting ischemia in patients with left bundle branch block than exercise thallium testing, and (3) subjective side effects were common and were of no diagnostic importance; transient AV block occurred occasionally.

Adenosine↗
PubMed1992

Ineffectiveness of colchicine for the prevention of restenosis after coronary angioplasty.

Colchicine, an antimitogenic agent, has shown promise in preventing restenosis after coronary angioplasty in experimental animal models. A prospective trial was conducted involving 197 patients randomized in a 2:1 fashion to treatment with oral colchicine, 0.6 mg twice daily (130 patients), or placebo (67 patients) for 6 months after elective coronary angioplasty. Treatment in all patients began between 12 h before angioplasty and 24 h after angioplasty. Compliance monitoring revealed that 96% of all prescribed pills were ingested. Demographic characteristics were similar in colchicine- and placebo-treated groups. A mean of 2.7 lesions/patient were dilated. Side effects resulted in a 6.9% dropout rate in the colchicine-treated patients. Complete quantitative angiographic follow-up was obtained in 145 patients (74%) with 393 dilated lesions. Quantitative angiographic measurements were obtained in two orthogonal views at baseline before angioplasty and immediately and at 6 months after angioplasty. The quantitative mean lumen diameter stenosis before angioplasty was 67% both in the 152 lesions in the placebo-treated group and in the 241 lesions in the colchicine-treated group; this value was reduced to 24% immediately after angioplasty in the lesions in both treatment groups. At the 6-month angiogram, lesions had restenosed to 47% lumen diameter narrowing in the placebo-treated group compared with 46% in the colchicine-treated group (p = NS). Forty-one percent of colchicine-treated patients developed restenosis in at least one lesion compared with 45% of the placebo-treated group (p = NS). In conclusion, colchicine was ineffective for preventing restenosis after coronary angioplasty.

Angioplasty, Balloon, Coronary↗