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Raymond J Gibbons

Publications and source records attributed to Raymond J Gibbons.

At least 37 records · Page 2Linked to original sources
PubMed2005

Revascularization in severe left ventricular dysfunction: the role of viability testing.

Revascularization is a treatment option for moderate-to-severe ischemic cardiomyopathy. Limitations of the current literature, lack of completed randomized trials, and higher periprocedural risks create significant uncertainty about the optimal treatment strategy. This review focuses on the available literature describing the effect of revascularization on outcome and the role of noninvasive viability testing. It attempts to identify a subset of patients likely to benefit from therapy.

Algorithms↗
PubMed2005

A randomized, double-blinded, placebo-controlled multicenter trial of adenosine as an adjunct to reperfusion in the treatment of acute myocardial infarction (AMISTAD-II).

OBJECTIVES: The purpose of this research was to determine the effect of intravenous adenosine on clinical outcomes and infarct size in ST-segment elevation myocardial infarction (STEMI) patients undergoing reperfusion therapy. BACKGROUND: Previous small studies suggest that adenosine may reduce the size of an evolving infarction. METHODS: Patients (n = 2,118) with evolving anterior STEMI receiving thrombolysis or primary angioplasty were randomized to a 3-h infusion of either adenosine 50 or 70 microg/kg/min or of placebo. The primary end point was new congestive heart failure (CHF) beginning >24 h after randomization, or the first re-hospitalization for CHF, or death from any cause within six months. Infarct size was measured in a subset of 243 patients by technetium-99m sestamibi tomography. RESULTS: There was no difference in the primary end point between placebo (17.9%) and either the pooled adenosine dose groups (16.3%) or, separately, the 50-microg/kg/min dose and 70-microg/kg/min groups (16.5% vs. 16.1%, respectively, p = 0.43). The pooled adenosine group trended toward a smaller median infarct size compared with the placebo group, 17% versus 27% (p = 0.074). A dose-response relationship with final median infarct size was seen: 11% at the high dose (p = 0.023 vs. placebo) and 23% at the low dose (p = NS vs. placebo). Infarct size and occurrence of a primary end point were significantly related (p < 0.001). CONCLUSIONS: Clinical outcomes in patients with STEMI undergoing reperfusion therapy were not significantly improved with adenosine, although infarct size was reduced with the 70-microg/kg/min adenosine infusion, a finding that correlated with fewer adverse clinical events. A larger study limited to the 70-microg/kg/min dose is, therefore, warranted.

Adenosine↗
PubMed2005

Exercise single-photon emission computed tomography provides effective risk stratification of elderly men and elderly women.

BACKGROUND: In a recent study, we reported that the Duke treadmill score was unable to effectively stratify elderly patients according to risk. The purpose of this study was to evaluate the prognostic value of exercise single-photon emission computed tomography (SPECT) in this same population and to examine results by gender. METHODS AND RESULTS: A cohort of 247 elderly (age > or =75 years) patients (108 women, 139 men, age 77+/-3 years) who underwent exercise thallium-201 SPECT were followed up for a median duration of 6.4 years. SPECT variables were significantly associated with cardiac death: summed stress score (SSS) chi2=19.5, P<0.001; summed difference score chi2=12.3, P<0.001; increased lung uptake chi2=9.6, P=0.002; and left ventricular enlargement chi2=8.3, P=0.004. The Duke score was not significantly associated with cardiac death (chi2<1, P=NS). The SSS classified most patients as low risk (49%) or high risk (35%); the Duke score classified the majority (68%) as intermediate risk. Annual cardiac mortality rates for patients categorized by SSS as low risk and high risk were 0.8% and 5.8%, respectively. Cardiac survival rates according to SSS risk categories were significantly different for both women (P=0.012) and men (P=0.003). CONCLUSIONS: SPECT classified most elderly patients into clinically useful low- and high-risk categories and accurately predicted outcomes in both genders. If these results can be validated in future studies, exercise SPECT rather than standard treadmill testing may emerge as the initial noninvasive testing strategy in elderly patients who are able to exercise.

Aged↗
PubMed2005

Distal microcirculatory protection during percutaneous coronary intervention in acute ST-segment elevation myocardial infarction: a randomized controlled trial.

CONTEXT: Atheromatous and thrombotic embolization during percutaneous coronary intervention (PCI) in acute myocardial infarction is common and may result in microcirculatory dysfunction, the prevention of which may improve reperfusion success, reduce infarct size, and enhance event-free survival. OBJECTIVE: To determine whether protection of the distal microcirculation from thromboembolic debris liberated during primary PCI results in improved reperfusion and decreased infarct size. DESIGN, SETTING, AND PATIENTS: Prospective randomized controlled trial at 38 academic and community-based institutions in 7 countries enrolling 501 patients aged 18 years or older with ST-segment elevation myocardial infarction (STEMI) presenting within 6 hours of symptom onset and undergoing primary PCI or rescue intervention after failed thrombolysis. INTERVENTIONS: Patients were randomized between May 20, 2002, and November 21, 2003, to receive PCI with a balloon occlusion and aspiration distal microcirculatory protection system vs angioplasty without distal protection. MAIN OUTCOME MEASURES: Coprimary end points were ST-segment resolution (STR) measured 30 minutes after PCI by continuous Holter monitoring and infarct size measured by technetium Tc 99m sestamibi imaging between days 5 and 14. Secondary end points included major adverse cardiac events. RESULTS: Among 252 patients assigned to distal protection, aspiration was performed in 97% (242/251), all angioplasty balloon inflations were fully protected in 79% (193/245), and visible debris was retrieved from 73% (182/250). Complete STR was achieved in a similar proportion reperfused with vs without distal protection (63.3% [152/240] vs 61.9% [148/239], respectively; absolute difference, 1.4% [95% confidence interval, -7.7% to 10.5%; P = .78]), and left ventricular infarct size was similar in both groups (median, 12.0% [n = 229] vs 9.5% [n = 208], respectively; P = .15). Major adverse cardiac events at 6 months occurred with similar frequency in the distal protection and control groups (10.0% vs 11.0%, respectively; P = .66). CONCLUSIONS: A distal balloon occlusion and aspiration system effectively retrieves embolic debris in most patients with acute STEMI undergoing emergent PCI. Nonetheless, distal embolic protection did not result in improved microvascular flow, greater reperfusion success, reduced infarct size, or enhanced event-free survival.

Aged↗
PubMed2005

Identifying high-risk asymptomatic diabetic patients who are candidates for screening stress single-photon emission computed tomography imaging.

OBJECTIVES: The purpose of this study was to identify which asymptomatic diabetic patients are candidates for screening single-photon emission computed tomography (SPECT) imaging and to examine angiographic findings and mortality in patients according to SPECT imaging categories. BACKGROUND: Previously we reported a high percentage of abnormal and high-risk SPECT imaging scans in asymptomatic diabetic patients. METHODS: We examined the associations between several clinical and laboratory variables and a high-risk stress SPECT imaging scan in 1,427 asymptomatic diabetic patients without known coronary artery disease (CAD). Results of coronary angiography and long-term outcome were also analyzed. RESULTS: An abnormal stress SPECT imaging scan was present in 826 patients (58%) and a high-risk scan in 261 patients (18%). Multivariate analysis demonstrated that seven variables were independently associated with a high-risk scan (model chi-square=107, p <0.0001). The two most important variables were electrocardiogram (ECG) Q waves (adjusted chi-square=38.3, p <0.001) and peripheral arterial disease (PAD) (adjusted chi-square=13.9, p <0.001). Coronary angiography was performed in 127 (49%) high-risk SPECT imaging patients, 61% of whom had angiographic high-risk CAD. Annual mortality rates for patient subsets categorized by SPECT imaging scans were high-risk 5.9%, intermediate-risk 5.0%, and low-risk 3.6% (p <0.001 for differences between groups). CONCLUSIONS: High-risk findings on stress SPECT imaging were present in 18% of asymptomatic diabetic patients without known CAD. Patients with high-risk scans had a high prevalence of severe CAD and a high annual mortality rate. ECG Q waves and/or evidence of PAD identified the most suitable candidates for screening.

Coronary Angiography↗
PubMed2005

Incremental prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium 201 imaging in patients with ST-T abnormalities on their resting electrocardiograms.

BACKGROUND: The incremental prognostic value of thallium 201 imaging in patients with nonspecific ST-T abnormalities on the resting electrocardiogram (ECG) may be different from those with a normal resting ECG. METHODS: Nine hundred thirty-nine consecutive patients with nonspecific ST-T abnormalities on their resting ECG who had undergone exercise 201 Tl imaging were followed for a median duration of 7.0 y (94% complete). The Cox proportional hazards regression model was used in a stepwise fashion to generate (1) a clinical (Cl) model, (2) a clinical and exercise (Cl + Ex) model, (3) and a clinical, exercise, and thallium (Cl + Ex + Tl) model, for the prediction of cardiac death. RESULTS: Age, sex, and diabetes composed the Cl model (chi2 = 63, P < .0001). The Duke treadmill score added to the Cl + Ex model (chi2 = 71, P < .0001). Increased lung uptake (P < .0001) added significantly and summed reversibility score ( P = .03) added modestly to the Cl + Ex + Tl model (chi2 = 96, P < .0001). On the basis of the Cl + Ex + Tl model, the low-, intermediate-, and high-risk groups had a 7-y survival free of cardiac death of 99%, 88%, and 58%, respectively (P < .0001). Using the Cl + Ex + Tl model, only a small number of low-risk and high-risk patients by the Cl + Ex model were reclassified. However, 48% of the 230 patients in the intermediate-risk group by the Cl + Ex model were reclassified as low risk or high risk. CONCLUSIONS: 201 Tl imaging has incremental prognostic value in patients with nonspecific abnormalities on their resting ECG. However, patients classified as low risk or high risk by exercise testing using the Cl + Ex model do not require 201 Tl imaging. Intermediate-risk patients should be further risk-stratified by 201 Tl imaging.

Aged↗
PubMed2005

Electrocardiographic infarct size assessment after thrombolysis: insights from the Acute Myocardial Infarction STudy ADenosine (AMISTAD) trial.

BACKGROUND: Noninvasive methods are needed to evaluate reperfusion success in patients with acute myocardial infarction (MI). The AMISTAD trial was analyzed to compare MI size and myocardial salvage determined by electrocardiogram (ECG) with technetium Tc 99m sestamibi single-photon emission computerized tomography (SPECT) imaging. METHODS: Of 236 patients enrolled in AMISTAD, 166 (70 %) with no ECG confounding factors and no prior MI were included in this analysis. Of these, group 1 (126 patients, 53%) had final infarct size (FIS) available by both ECG and SPECT. Group 2 (56 patients, 24%) had myocardium at risk, FIS, and salvage index (SI) assessed by both SPECT and ECG techniques. Aldrich/Clemmensen scores for myocardium at risk and the Selvester QRS score for final MI size were used. Salvage index was calculated as follows: SI = (myocardium at risk-FIS)/(myocardium at risk). RESULTS: In group 1, FIS was 15% (6, 24) as measured by ECG and 11% (2, 27) as measured by SPECT. In the adenosine group, FIS was 12% (6, 21) and 11% (2, 22). In the placebo group, FIS was 16.5% (7.5, 24) and 11.5% (3.0, 38.5) by ECG and SPECT, respectively. The overall correlation between SPECT and ECG for FIS was 0.58 (P = .0001): 0.60 in the placebo group (P = .0001) and 0.54 (P = .0001) in the adenosine group. In group 2, myocardium at risk was 23% (17, 30) and 26% (10, 50) with ECG and SPECT, respectively (P = .0066). Final infarct size was 17% (6, 21) and 12% (1, 24) (P < .0001). The SI was 29% (-7, 57) and 46% (15, 79) with ECG and SPECT, respectively (P = .0510). CONCLUSIONS: The ECG measurement of infarct size has a moderate relationship with SPECT infarct size measurements in the population with available assessments. This ECG algorithm must further be validated on clinical outcomes.

Adenosine↗
PubMed2005

A simple clinical score accurately predicts outcome in a community-based population undergoing stress testing.

PURPOSE: Scoring systems based on clinical variables are available but not widely applied for evaluating patients with chronic coronary artery disease. The purpose of this study was to validate the prognostic value of a simple clinical scoring system, originally developed in patients referred for a nuclear stress test at a tertiary-care medical center, in a less-selected, community-based population undergoing stress testing for known or suspected coronary artery disease. SUBJECTS AND METHODS: Over a 4-year period, 3546 residents of Olmsted County, Minn, underwent stress testing. A previously developed clinical score was calculated for every patient by assigning 1 point each for: male sex, history of myocardial infarction, typical angina, diabetes, insulin use, and each decade of age beginning at age 40. The associations between the assigned score and clinical endpoints were tested using logistic regression. A previously established cutoff point of 5 was used to establish risk groups. RESULTS: During follow-up (7.6 +/- 2.7 years) there were 363 total deaths, 109 cardiac deaths, and 132 nonfatal myocardial infarctions. The clinical score was strongly associated with overall mortality, cardiac death, and cardiac death/myocardial infarction (P <0.001 for all 3 endpoints). Annual mortality was .6% for the 3076 patients (86%) with a score < or =4, 2.4% for 275 patients (8%) with a score = 5 and 6.2% for the 215 patients (6%) with a score > or =6. CONCLUSIONS: This study enhances the generalizability of this simple clinical score, which was highly effective for risk-stratifying this community-based population undergoing evaluation of chronic coronary artery disease.

Coronary Angiography↗
PubMed2005

Quantitation of regional ejection fractions using gated tomographic imaging with 99mTc-sestamibi.

BACKGROUND: Gated single photon emission CT (SPECT) sestamibi imaging allows the simultaneous assessment of myocardial perfusion and left ventricular function. OBJECTIVE: The purpose of this study was to evaluate a technique for quantitative regional wall motion assessment using gated SPECT (99m)Tc-sestamibi imaging. PATIENTS AND INTERVENTIONS: Fourteen subjects without cardiac pathology and 25 patients who had experienced myocardial infarction (MI) were studied. After tomographic reconstruction of gated short-axis slices, the identification of endocardial borders was made using a standard edge-detection program in systole and diastole in each of five selected slices. Regional ejection fraction (EF) and myocardial perfusion were determined for five regions within each slice. Ten patients underwent echocardiographic regional wall-motion analysis, the results of which were compared to corresponding regional EF results. RESULTS: High interobserver reproducibility in the assessment of regional EFs was found, with r values ranging from 0.94 to 0.98. In patients with anterior and inferior MIs, the regional EFs were abnormal in the anterior and septal regions, and the inferior and lateral regions, respectively. The regional EFs correlated significantly with regional perfusion in the anterior walls (r = 0.71; p = 0.0001), the lateral walls (r = 0.66; p = 0.0001), and inferior walls (r = 0.54; p = 0.0004). There was a significant association between the regional EFs and the echocardiographic regional wall motion assessment at the base (p < 0.0001), mid-ventricle (p = 0.0004), and apex (p = 0.0003). CONCLUSIONS: Gated SPECT images obtained (99m)Tc-sestamibi can provide reproducible quantitative, segmental regional EFs for multiple left ventricular slices that are significantly associated with subjective regional wall motion assessment by echocardiography.

Adult↗
PubMed2005

Effect of exercise treadmill testing and stress imaging on the triage of patients with chest pain: CHEER substudy.

OBJECTIVE: To determine whether stress imaging for patients who are unsuitable for exercise treadmill testing (ETT) as part of a chest pain unit (CPU) triage strategy resulted in incremental benefit in clinical outcomes and relative costs compared with patients randomized to routine hospital admission. PATIENTS AND METHODS: Clinical outcomes and medical resource utilization were examined at the Mayo Clinic in Rochester, Minn, for 212 intermediate-risk patients with unstable angina randomized to a CPU and compared with 212 patients randomized to routine admission from November 21, 1995, to March 18, 1997. Patients in stable condition in the CPU underwent ETT; if patients were unsuitable for ETT, stress imaging was performed. Costs for CPU evaluation and outcomes were assessed during a 6-month follow-up. RESULTS: During the observation period, 60 patients (28%) were admitted to the hospital. Of the 152 remaining patients, 125 (82%) underwent ETT (91 had normal results), and 27 (18%) underwent stress imaging (3 had normal results). Patients with normal ETT or stress imaging results had no primary events at 6-month follow-up. Patients admitted to the hospital who underwent stress imaging had an insignificantly higher 6-month event rate compared with patients who underwent ETT (16.7% vs 8.1%; P=.38). The standardized resource-based relative-value units (RBRVUs) for patients who underwent ETT and stress imaging during follow-up were 19.4 and 56.4 RBRVUs, respectively, compared with 51.4 (ETT) and 52.1 (stress imaging) RBRVUs for similar numbers of patients randomized to routine admission. CONCLUSIONS: Exercise treadmill testing safely stratified most intermediate-risk patients with unstable angina and was less costly than routine admission. Patients not suitable for ETT are likely to have abnormal stress imaging results. They represent a higher-risk cohort that could be routinely admitted to the hospital without reducing the effectiveness of the CPU strategy.

Angina, Unstable↗
PubMed2004

The quantification of infarct size.

We sought to summarize the published evidence regarding the measurement of infarct size by serum markers, technetium-99m sestamibi single-photon emission computed tomography (SPECT) myocardial perfusion imaging, and magnetic resonance imaging. The measurement of infarct size is an attractive surrogate end point for the early assessment of new therapies for acute myocardial infarction. For each of these three approaches, we reviewed reports published in English providing the clinical validation for the measurement of infarct size and the relevant clinical trial experience. The measurement of infarct size by serum markers has multiple theoretical and practical limitations. The measurement of troponin is promising, but the available data validating this marker are limited. Sestamibi SPECT imaging has five separate lines of published evidence supporting its validity and has received extensive study in multicenter trials. Magnetic resonance imaging has great promise but has less clinical validation and no multicenter trial experience. Therefore, SPECT sestamibi imaging is currently the best available technique for the quantitation of infarct size to assess the incremental treatment benefit of new therapies in multicenter trials of acute myocardial infarction.

Biomarkers↗
PubMed2004

Primary care management of chronic stable angina and asymptomatic suspected or known coronary artery disease: a clinical practice guideline from the American College of Physicians.

In 1999, the American College of Physicians (ACP), then the American College of Physicians-American Society of Internal Medicine, and the American College of Cardiology/American Heart Association (ACC/AHA) developed joint guidelines on the management of patients with chronic stable angina. The ACC/AHA then published an updated guideline in 2002, which ACP recognized as a scientifically valid review of the evidence and background paper. This ACP guideline summarizes the recommendations of the 2002 ACC/AHA updated guideline and underscores the recommendations most likely to be important to physicians seeing patients in the primary care setting. This guideline is the second of 2 that provide guidance on the management of patients with chronic stable angina. This document covers treatment and follow-up of symptomatic patients who have not had an acute myocardial infarction or revascularization procedure in the previous 6 months. Sections addressing asymptomatic patients are also included. Asymptomatic refers to patients with known or suspected coronary disease based on a history or electrocardiographic evidence of previous myocardial infarction, coronary angiography, or abnormal results on noninvasive tests. A previous guideline covered diagnosis and risk stratification for symptomatic patients who have not had an acute myocardial infarction or revascularization procedure in the previous 6 months and asymptomatic patients with known or suspected coronary disease based on a history or electrocardiographic evidence of previous myocardial infarction, coronary angiography, or abnormal results on noninvasive tests.

Angina Pectoris↗