47 research outputs found
Myocardial stress imaging: a clinical tool has come of age
Coronary artery disease is a major cause of morbidity and mortality in the western
world (1 ). Depending on the progression and severity of coronary artery disease and the
myocardial response this may result in angina pectoris, myocardial infarction, chronic
ischemic heart disease and cardiac death. Several techniques have been developed to evaluate
patients with known or suspected coronary artery disease.
In 1973, Strauss and Zaret and coworkers (2,3) hypothesized that exercise should be
used to maximize differences in relative perfusion bet\veen normal and abnormal coronary
vascular beds during myocardial perfusion imaging. This is a safe and simple noninvasive
way of assessing myocardial perfusion at rest and to detect myocardial ischemia. In 1979,
Wann and colleagues (4) demonstrated that the mechanical consequences of ischemia can be
detected noninvasively by real-time two-dimensional stress echocardiography. Since then,
advances in exercise and pharmacological stress protocols, developments in nuclear
cardiology, and significant improvements in echocardiographic equipment have provided the
foundation for the growth of myocardial stress imaging (5-11 ).
Myocardial stress imaging has seen little to parallel its rapid development. Currently,
noninvasive imaging of the heart using radionuclide tracers under stress and resting
conditions and dobutamine stress echocardiography are established techniques for the
evaluation of patients with known or suspected coronary artery disease. Myocardial stress
imaging can b
Contrast-enhanced ultrasound: clinical applications in patients with atherosclerosis
Contrast-enhanced ultrasound (CEUS) is increasingly being used to evaluate patients with known or suspected atherosclerosis. The administration of a microbubble contrast agent in conjunction with ultrasound results in an improved image quality and provides information that cannot be assessed with standard B-mode ultrasound. CEUS is a high-resolution, noninvasive imaging modality, which is safe and may benefit patients with coronary, carotid, or aortic atherosclerosis. CEUS allows a reliable assessment of endocardial borders, left ventricular function, intracardiac thrombus and myocardial perfusion. CEUS results in an improved detection of carotid atherosclerosis, and allows assessment of high-risk plaque characteristics including intraplaque vascularization, and ulceration. CEUS provides real-time bedside information in patients with a suspected or known abdominal aortic aneurysm or aortic dissection. The absence of ionizing radiation and safety of the contrast agent allow repetitive imaging which is particularly useful in the follow-up of patients after endovascular aneurysm repair. New developments in CEUS-based molecular imaging will improve the understanding of the pathophysiology of atherosclerosis and may in the future allow to image and directly treat cardiovascular diseases (theragnostic CEUS). Familiarity with the strengths and limitations of CEUS may have a major impact on the management of patients with atherosclerosis
Impact of Early Coronary Revascularization on Long-Term Outcomes in Patients With Myocardial Ischemia on Dobutamine Stress Echocardiography
The role of early coronary revascularization in the management of stable coronary artery disease remains controversial. The aim of this study was to evaluate the impact of early coronary revascularization on long-term outcomes (>10Â years) after an ischemic dobutamine stress echocardiography (DSE) in patients with known or suspected coronary artery disease. Patients without stress-induced ischemia on DSE and those who underwent late coronary revascularization (>90Â days after DSE) were excluded. The final study cohort consisted of 905 patients. A DSE with a peak wall motion score index of 1.1 to 1.7 was considered mild
Long-term (>10 years) prognostic value of dobutamine stress echocardiography in a high-risk cohort
The prognostic value of dobutamine stress echocardiography (DSE) at >10-year follow-up is unknown. The aim of this study was to assess the very long-term prognostic value of DSE in a high-risk cohort of patients with known or suspected coronary artery disease. This prospective, single-center study included 3,381 patients who underwent DSE from January 1990 to January 2003. Two-dimensional echocardiographic images were acquired at rest, during dobutamine stress, and during recovery. Follow-up events were collected and included overall mortality, cardiac death, nonfatal myocardial infarction, and revascularization. The incremental value of DSE in the prediction of selected end points was evaluated using multivariate Cox proportional hazard analysis. During a mean follow-up of 13 ± 3.2 years (range 7.3 to 20.5 years), there were 1,725 deaths (51%), of which 1,128 (33%) were attributed to cardiac causes. Patients with an abnormal DSE had a higher mortality rate (44% vs 35% at 15-year follow-up, p <0.001) than those with a normal DSE. When comparing echocardiographic variables at rest to variables at maximum dose dobutamine, the chi-square of the test improved from 842 to 870 (p <0.0001) and from 684 to 740 (p <0.0001) for all-cause mortality and cardiac death, respectively. DSE provided incremental value in predicting all-cause mortality, cardiac death, and hard cardiac events. There seems, however, to be a "warranty period" of approximately 7 years, when the survival curves of a normal and abnormal DSE no longer diverge
Impact of sex on timing and clinical outcome of septal myectomy for obstructive hypertrophic cardiomyopathy
Background: Sex disparities are common in hypertrophic cardiomyopathy (HCM). Previous research has shown that at time of myectomy, women are older, have greater impairment of diastolic function and more advanced cardiac remodeling. The clinical impact of these differences is unknown. Method: This study included 162 HCM patients (61% m
Long-term prognostic value of dobutamine stress 99mTc-sestamibi SPECT: single-center experience with 8-year follow-up
PURPOSE: To determine the long-term prognostic value of dobutamine stress
technetium 99m (99mTc)-labeled sestamibi single photon emission computed
tomography (SPECT) in patients with limited exercise capacity. MATERIALS
AND METHODS: Clinical data and SPECT results were analyzed in 531
consecutive patients. Follow-up was successful in 528 (99.4%) patients; 55
underwent early revascularization and were excluded. Normal or abnormal
findings were considered in the absence or presence of fixed and/or
reversible perfusion defects. A summed stress score was calculated to
estimate the extent and severity of perfusion defects. Univariate and
multivariate Cox proportional hazards regression models were used to
identify independent predictors of late cardiac events. The incremental
value of myocardial perfusion scintigraphy over clinical variables in
predicting events was determined according to two models. The probability
of survival was calculated by using the Kaplan-Meier method. RESULTS:
Findings were abnormal in 312 patients. During 8.0 years +/- 1.5 of
follow-up (range, 4.5-10.6 years), cardiac death occurred in 67 patients
(total deaths, 165); nonfatal myocardial infarction, in 34; and late
revascularization, in 49. The annual rates for cardiac death, cardiac
death or infarction, and all events were 0.9%, 1.2%, and 1.5%,
respectively, after normal findings and 2.7%, 3.4%, and 4.4%,
respectively, after abnormal findings (P <.05). In a multivariable Cox
proportional hazards model, not only an abnormal finding but also the
summed stress score provided incremental prognostic information in
addition to clinical data. The hazard ratio for cardiac death was 1.09
(95% CI: 1.01, 1.18) per 1-unit increment of the summed stress score.
CONCLUSION: The incremental prognostic value of dobutamine stress
99mTc-sestamibi SPECT over clinical data was maintained over an 8-year
follow-up in patients with limited exercise capacity
Noninvasive evaluation of ischaemic heart disease: myocardial perfusion imaging or stress echocardiography?
Stress echocardiography and myocardial perfusion imaging are commonly used noninvasive imaging modalities for the evaluation of ischaemic heart disease. Both modalities have proved clinically useful in the entire spectrum of coronary artery disease. Both techniques can detect coronary artery disease and provide prognostic information. Both techniques can identify low-risk and high-risk subsets among patients with known or suspected coronary artery disease and thus guide patient management decisions. In patients with acute myocardial infarction, both techniques have been used to identify residual viable tissue and predict improvement of function over time. In patients with chronic ischaemic left ventricular (LV) dysfunction, viability assessment with either modality can be used to predict improvement of function after revascularisation and thus guide patient treatment