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Robert C Hendel

Publications and source records attributed to Robert C Hendel.

At least 19 recordsLinked to original sources
PubMed2006

ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR 2006 appropriateness criteria for cardiac computed tomography and cardiac magnetic resonance imaging: a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American College of Radiology, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, American Society of Nuclear Cardiology, North American Society for Cardiac Imaging, Society for Cardiovascular Angiography and Interventions, and Society of Interventional Radiology.

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Cardiovascular Diseases↗
PubMed2006

Cardiovascular disease risk stratification with stress single-photon emission computed tomography technetium-99m tetrofosmin imaging in patients with the metabolic syndrome and diabetes mellitus.

The metabolic syndrome represents a constellation of risk factors caused by insulin resistance, dyslipidemia, hypertension, and obesity, resulting in elevated coronary disease risk. From a multicenter prospective registry of 7,849 patients, the relation among the metabolic syndrome, diabetes, and risk stratification with stress technetium-99m tetrofosmin single photon-emission computed tomography (SPECT) was evaluated. The percentage of stress myocardial defects was calculated as < or = 5%, 5.1% to 10%, 10.1% to 15%, and > 15%. A Cox proportional-hazards model was used to estimate cardiovascular death or myocardial infarction (n = 752). Of 7,849 patients, 42% had the metabolic syndrome. Patients with the metabolic syndrome had an 84% 2-year event-free survival rate, lower than patients with normal metabolic status (p <0.0001). In patients with the metabolic syndrome, the percentage of moderate to severely abnormal SPECT findings ranged from 11% to 44% for those with 3 to 5 risk factors for the metabolic syndrome. There was an additive relation between the number of risk factors for the metabolic syndrome and the extent and severity of abnormalities in SPECT findings (p <0.0001). Patients with 5 risk factors for the metabolic syndrome were at the greatest risk, with hazard ratios from 7.8- to 14.1-fold for mild to severely abnormal SPECT findings. For diabetic patients requiring combined oral and insulin therapy, relative risk ratios increased from 15 to 21.4 for patients with > 5% to > 15% stress myocardial perfusion defects. In conclusion, cardiovascular prognosis is affected by the degree of metabolic dysfunction, and stress-induced reductions in myocardial perfusion provide an accurate means for near-term risk stratification.

Aged↗
PubMed2005

Initial clinical experience with regadenoson, a novel selective A2A agonist for pharmacologic stress single-photon emission computed tomography myocardial perfusion imaging.

OBJECTIVES: Regadenoson, a selective A2A adenosine receptor agonist, was evaluated for tolerability and effectiveness as a pharmacological stress agent for detecting reversible myocardial hypoperfusion when combined with single-photon emission computed tomography (SPECT). BACKGROUND: Adenosine and dipyridamole are nonselective adenosine agonists currently used as pharmacologic stressors. Despite proven safety, these agents often cause undesirable side effects and require a continuous infusion. METHODS: This Phase II, multicenter, open-label trial was conducted in 36 patients who had demonstrated ischemia on a 6-min adenosine SPECT imaging study within the previous 2 to 46 days. Patients received regadenoson as a rapid intravenous bolus dose of 400 microg (n = 18) or 500 microg (n = 18). The radiopharmaceutical was then delivered within one minute. The SPECT images were acquired in a standard manner and uniformly processed at a central laboratory. Regadenoson and adenosine studies were presented in random order and interpreted blindly with a 17-segment model by three observers. Additionally, quantitative analysis was performed with 4D-MSPECT software (University of Michigan, Ann Arbor, Michigan). RESULTS: Overall agreement for the presence of reversible hypoperfusion was 86%. The 400-mug dose was better tolerated. Overall, regadenoson was well-tolerated; side effects (e.g., chest discomfort, flushing, dyspnea) were generally mild in severity and self-limiting. High-grade atrioventricular block and bronchospasm were not observed. CONCLUSIONS: Regadenoson is well-tolerated and seems as effective as adenosine for detecting and quantifying the extent of hypoperfusion observed with SPECT perfusion imaging. Phase III clinical trials are now underway, given the promise of regadenoson's reduced side effects and simplicity of bolus administration.

Adenosine↗
PubMed2005

A blinded, randomized, placebo-controlled trial of percutaneous laser myocardial revascularization to improve angina symptoms in patients with severe coronary disease.

OBJECTIVES: This study was a randomized, patient- and evaluator-blinded, placebo-controlled trial in patients treated using percutaneous myocardial laser revascularization. BACKGROUND: Previous studies using similar therapies have been confounded by placebo bias. METHODS: A total of 298 patients with severe angina were randomly assigned to receive low-dose or high-dose myocardial laser channels or no laser channels, blinded as a sham procedure. The primary end point was the change in exercise duration from baseline examination to six months. RESULTS: The incidence of 30-day death, stroke, myocardial infarction, coronary revascularization, or left ventricular perforation occurred in two patients in the placebo, eight patients in the low-dose, and four patients in the high-dose groups (p = 0.12); 30-day myocardial infarction incidence was higher in patients receiving either low-dose or high-dose laser (nine patients) compared with placebo (no patients, p = 0.03). At six months, there were no differences in the change in exercise duration between those receiving a sham (28.0 s, n = 100), low-dose laser (33.2 s, n = 98), or high-dose laser (28.0 s, n = 98, p = 0.94) procedure. There were also no differences in the proportion of patients improving to better than Canadian Cardiovascular Society class III angina symptoms at six months. The follow-up visual summed stress single-photon-emission computed tomography scores were not significantly different from baseline in any group and were no different between groups. The modest improvement in angina symptoms assessed by the Seattle Angina Questionnaire also was not statistically different among the arms. CONCLUSIONS: Treatment with percutaneous myocardial laser revascularization provides no benefit beyond that of a similar sham procedure in patients blinded to their treatment status.

Angina Pectoris↗
PubMed2005

ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI): a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group and the American Society of Nuclear Cardiology endorsed by the American Heart Association.

Under the auspices of the American College of Cardiology Foundation (ACCF) and the American Society of Nuclear Cardiology (ASNC), an appropriateness review was conducted for radionuclide cardiovascular imaging (RNI), specifically gated single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). The review assessed the risks and benefits of the imaging test for several indications or clinical scenarios and scored them based on a scale of 1 to 9, where the upper range (7 to 9) implies that the test is generally acceptable and is a reasonable approach, and the lower range (1 to 3) implies that the test is generally not acceptable and is not a reasonable approach. The mid range (4 to 6) implies that the test may be generally acceptable and may be a reasonable approach for the indication. The indications for this review were primarily drawn from existing clinical practice guidelines and modified based on discussion by the ACCF Appropriateness Criteria Working Group and the Technical Panel members who rated the indications. The method for this review was based on the RAND/UCLA approach for evaluating appropriateness, which blends scientific evidence and practice experience. A modified Delphi technique was used to obtain first- and second-round ratings of 52 clinical indications. The ratings were done by a Technical Panel with diverse membership, including nuclear cardiologists, referring physicians (including an echocardiographer), health services researchers, and a payer (chief medical officer). These results are expected to have a significant impact on physician decision making and performance, reimbursement policy, and future research directions. Periodic assessment and updating of criteria will be undertaken as needed.

Coronary Circulation↗
PubMed2005

Ethnic differences in the prognostic value of stress technetium-99m tetrofosmin gated single-photon emission computed tomography myocardial perfusion imaging.

OBJECTIVES: This study was designed to evaluate the differential prognostic value of gated single-photon emission computed tomographic imaging (SPECT) imaging in an ethnically diverse multicenter registry. BACKGROUND: Ethnic minority patient populations have reportedly higher coronary heart disease mortality with greater comorbidity and a clustering of risk factors at a significantly younger age when compared with Caucasian, non-Hispanic patients. Despite our increasingly diverse population, the predictive accuracy of cardiac imaging in ethnic minority patients is ill-defined. METHODS: A total of 7,849 patients were prospectively enrolled in a registry of patients undergoing exercise (44%) or pharmacologic stress (56%) technetium-99m tetrofosmin SPECT. Scans were scored using a 20-segment myocardial model with a 5-point severity index. Multivariable Cox proportional hazards models were employed to assess time to death or myocardial infarction. RESULTS: A total of 1,993 African-American, 464 Hispanic, and 5,258 Caucasian non-Hispanic patients underwent SPECT imaging. African-American and Hispanic patients more often had a history of stroke, peripheral arterial disease, angina, heart failure, diabetes, hypertension, and smoking at a younger age. Moderate or severely abnormal SPECT scans were noted in 21%, 17%, and 13% of African-American, Hispanic, and Caucasian non-Hispanic patients, respectively (p < 0.0001). Cardiovascular death rates were highest for ethnic minority patients (p < 0.0001). Annual rates of ischemic heart disease death ranged from 0.2% to 3.0% for Caucasian non-Hispanic and 0.8% to 6.5% for African-American patients with low-risk to severely abnormal SPECT scans (p < 0.0001). For post-stress ejection fraction <45%, annualized risk-adjusted death rates were 2.7% for Caucasian non-Hispanic patients versus 8.0% and 14.0% for African-American and Hispanic patients (p < 0.0001). CONCLUSIONS: The current results from a large observational registry reveal that exercise and pharmacologic stress SPECT effectively predicts major cardiovascular events in a large cohort of African-American and Hispanic patients evaluated for suspected myocardial ischemia. These results provide further evidence that ethnic minority patient populations have a worsening outcome related to cardiovascular disease.

Black or African American↗
PubMed2004

Gender differences in the value of ST-segment depression during adenosine stress testing.

Previous studies have suggested that ST-segment depression with adenosine myocardial perfusion imaging (MPI) may be a marker of significant coronary artery disease (CAD). It is unclear if the significance of ST depression differs between men and women. We investigated the diagnostic accuracy of ST-segment depression with adenosine radionuclide MPI as a marker of significant CAD in men and women. Consecutive patients who had angina or suspected CAD and underwent an adenosine stress test and subsequent angiography were retrospectively analyzed. The inclusion criteria were met by 959 patients. Mean age was 64 +/- 11 years, and 43% were women. ST depression occurred in 7.6% of the cohort and more often in women (64% women vs 36% men, p <0.001). Among men and women, patients with ST-segment depression had a significantly higher peak rate-pressure product, more chest pain, and a higher ejection fraction in response to the adenosine infusion compared with those without ST-segment depression. ST-segment depression occurred more often in the presence of stenotic lesions (>/=50% and >/=70%), and left main or 3-vessel disease, regardless of gender. Transient ischemic dilation occurred more often in men with ST-segment depression. The logistic regression analysis demonstrated that the only significant predictors of left main or 3-vessel CAD were gender, an abnormal result on MPI, transient ischemic dilation, and ST-segment depression. In conclusion, ST-segment depression during adenosine MPI is an important marker of angiographically significant CAD in men and women. The presence of ST-segment depression is associated with left main disease and 3-vessel CAD.

Adenosine↗
PubMed2004

The diagnostic and prognostic value of ECG-gated SPECT myocardial perfusion imaging.

Since the development of gated SPECT imaging approximately 10 y ago, this technique is now almost universally used as an adjunct for radionuclide perfusion imaging, enabling the assessment of perfusion along with determination of regional and global left ventricular function in the same examination. The gated SPECT determination of the left ventricular ejection fraction and volumes has been extensively validated. Additionally, this method allows for the improved identification of soft-tissue artifacts and enhances the detection of multivessel coronary artery disease. Furthermore, gated SPECT provides powerful information for the risk assessment of patients with known or suspected coronary artery disease and aids in the assessment of myocardial viability. Gated SPECT imaging has clearly become an integral part of radionuclide myocardial perfusion imaging.

Artifacts↗
PubMed2003

Comparison of echocardiography using tissue harmonics and contrast harmonics with radionuclide angiography for the assessment of left ventricular function.

BACKGROUND: Left ventricular ejection fraction (LVEF) is a significant predictor of morbidity and mortality; however, the optimal noninvasive modality for the quantitative determination of LVEF is not apparent. HYPOTHESIS: We verified the hypothesis that the various echocardiographic methods of assessing LVEF using the Method of Discs with contrast (Optison human albumin microspheres; Amersham Health, Princeton, NJ) and visual assessment of LVEF using tissue harmonics and contrast harmonics compare favorably with radionuclide angiography (RNA). METHODS: In a prospective analysis, 24 consecutive patients scheduled to undergo RNA had an echocardiogram using tissue harmonics and contrast harmonics on the same day. LVEF was assessed by RNA by an experienced, blinded reader using manual determination of the region of interest. LVEF was calculated using the Method of Discs (Simpson's Rule) by a blinded sonographer. LVEF was visually estimated by two blinded readers using echocardiography with tissue harmonics and contrast harmonics on separate occasions. RESULTS: By linear regression analysis, LVEF determination by echocardiography with contrast using the Method of Discs correlated well with RNA (r = .835, p < .0005). Using Bland-Altman analysis, the second echocardiogram reader had excellent agreement with RNA, whereas the first reader had a mean difference of 5.25% (CI 1.3-9.2; p = .012) with visual assessment using tissue harmonics and a mean difference of 4.67% (CI 0.4-8.8; p = .031) with visual assessment using contrast harmonics compared with RNA. Thus, a small difference in agreement between RNA and echocardiographic visual estimation was noted that appeared to be primarily reader dependent. CONCLUSIONS: LVEF determination with echocardiography with contrast using the Method of Discs correlated well with RNA and provided agreement across a range of cardiac functions. Visual echocardiographic assessment of LVEF with both tissue harmonics and contrast harmonics correlated well with RNA, but contrast harmonics did not appear to offer an advantage over tissue harmonics alone.

Adult↗
PubMed2003

Improved in-hospital outcomes in acute coronary syndromes (unstable angina/non-ST segment elevation myocardial infarction) despite similar TIMI risk scores.

BACKGROUND: The Thrombolysis In Myocardial Infarction (TIMI) Risk Score has been shown to predict prognosis in acute coronary syndromes (ACS) comprised of unstable angina (UA) and non-ST segment elevation myocardial infarction (STEMI). We sought to evaluate the impact of newer antiplatelet and antithrombotic therapies for ACS, such as glycoprotein IIb/IIIa inhibitors (GPI) and low molecular weight heparin (LMWH), on in-hospital outcomes over time in patients (pts) with similar TIMI risk scores. METHODS: The baseline demographics and clinical outcomes of pts with ACS (UA and non-STEMI) in 1998 (Group 1998) and 2000 (Group 2000) at a single large university medical center were compared using a prospectively collected database. In-hospital major adverse cardiac events (MACE) included death, MI, or recurrent angina that resulted in urgent revascularization. Risk was estimated by utilizing the TIMI Risk Score, which uses 7 predictor variables: age > 65 years, at least 3 risk factors for coronary artery disease, prior coronary stenosis of 50%, ST segment deviation on EKG, severe angina, prior aspirin use, and elevated cardiac biomarkers. RESULTS: Comparing Group 1998 (n = 563) and Group 2000 (n = 604), there was no difference between the mean TIMI Risk Score (2.90 1.52 vs. 2.91 1.52; p = 0.97), demonstrating a similar risk profile. Nevertheless, significant improvement in in-hospital MACE (9.1% vs. 2.8%; p < 0.001) was noted. The improvement in MACE was due to differences in rates of recurrent angina, without significant differences in death and myocardial infarction. This occurred temporally in association with a significant increase in GPI (1.0% vs. 8.3%; p < 0.01) and LMWH (0.0% vs. 15.6%; p < 0.001) use within 24 hours of presentation, and the increased utilization of intracoronary stenting (46.6% vs. 64.6%; p = 0.005), findings which were confirmed with multivariate analysis. CONCLUSION: Despite similar TIMI Risk Scores, the in-hospital outcomes of pts with ACS have improved over time. This temporal change is associated with the greater use of newer antiplatelet and antithrombotic therapies and increased utilization of intracoronary stenting.

Aged↗
PubMed2002

Myocardial perfusion imaging for evaluation and triage of patients with suspected acute cardiac ischemia: a randomized controlled trial.

CONTEXT: Observational studies of acute myocardial perfusion imaging in emergency department (ED) patients with chest pain have suggested high sensitivity and negative predictive value for acute cardiac ischemia, but use of this method has not been prospectively tested. OBJECTIVE: To assess whether incorporating acute resting perfusion imaging into an ED evaluation strategy for patients with suspected acute ischemia but no initial electrocardiogram (ECG) changes diagnostic of acute ischemia improves clinical decision making for initial ED triage. DESIGN, SETTING, AND PATIENTS: Prospective, randomized controlled trial conducted at 7 academic medical centers and community hospitals between July 1997 and May 1999 among 2475 adult ED patients with chest pain or other symptoms suggestive of acute cardiac ischemia and with normal or nondiagnostic initial ECG results. INTERVENTION: Patients were randomly assigned to receive either the usual ED evaluation strategy (n = 1260) or the usual strategy supplemented with results from acute resting myocardial perfusion imaging using single-photon emission computed tomography with injection of 20 to 30 mCi of Tc-99m sestamibi (n = 1215), interpreted in real time by local staff physicians and with results provided to the ED physician for incorporation into clinical decision making. MAIN OUTCOME MEASURE: Appropriateness of triage decision either to admit to hospital/observation or to discharge directly home from the ED. RESULTS: Among patients with acute cardiac ischemia (ie, acute myocardial infarction [MI] or unstable angina; n = 329), there were no differences in ED triage decisions between those receiving standard evaluation and those whose evaluation was supplemented by a sestamibi scan. Among patients with acute MI (n = 56), 97% vs 96% were hospitalized (relative risk [RR], 1.00; 95% confidence interval [CI], 0.89-1.12), and among those with unstable angina (n = 273), 83% vs 81% were hospitalized (RR, 0.98; 95% CI, 0.87-1.10). However, among patients without acute cardiac ischemia (n = 2146), hospitalization was 52% with usual care vs 42% with sestamibi imaging (RR, 0.84; 95% CI, 0.77-0.92). CONCLUSIONS: Sestamibi perfusion imaging improves ED triage decision making for patients with symptoms suggestive of acute cardiac ischemia without obvious abnormalities on initial ECG. In this study, unnecessary hospitalizations were reduced among patients without acute ischemia, without reducing appropriate admission for patients with acute ischemia.

Acute Disease↗
PubMed2002

Phase 1/2 placebo-controlled, double-blind, dose-escalating trial of myocardial vascular endothelial growth factor 2 gene transfer by catheter delivery in patients with chronic myocardial ischemia.

BACKGROUND: This phase 1/2 study investigated the safety of percutaneous catheter-based gene transfer of naked plasmid DNA encoding for vascular endothelial growth factor 2 (phVEGF2) to left ventricular (LV) myocardium in a prospective, randomized, double-blind, placebo-controlled, dose-escalating study of inoperable patients with class III or IV angina. METHODS AND RESULTS: A steerable deflectable 8F catheter with a 27-gauge needle at its distal tip was advanced percutaneously to the endocardial surface of the LV in 19 patients (age, 61+/-2 years) with chronic myocardial ischemia who were not candidates for conventional revascularization. Patients were randomized in a double-blind fashion to receive 6 injections (total volume, 6.0 mL) of placebo or phVEGF2 in doses of 200 microg (n=9), 800 microg (n=9), or 2000 microg (n=1) guided by LV electromechanical (NOGA) mapping with a gene-to-placebo ratio of 2:1. A total of 114 LV injections were delivered and caused no hemodynamic alterations, sustained ventricular arrhythmias, ECG evidence of infarction, or ventricular perforation. End-point analysis at 12 weeks disclosed a statistically significant improvement in Canadian Cardiovascular Society (CCS) angina class in phVEGF2-treated versus placebo-treated patients (-1.3 versus -0.1, P=0.04). Remaining efficacy end points--including change in exercise duration (91.8 versus 3.9 seconds), functional improvement by > or =2 CCS classes (9 of 12 versus 1 of 6), and Seattle Angina Questionnaire data--all showed strong trends favoring efficacy of phVEGF2 versus placebo treatment. CONCLUSIONS: This phase 1/2, double-blind, randomized trial provides preliminary data that support safety of phVEGF2 catheter-mediated myocardial gene transfer. The statistically significant reduction in anginal class and strong positive trends for remaining end points suggest that a larger phase 2/3 trial is warranted.

Angina Pectoris↗