3,872 research outputs found
Prognostic impact of coronary microcirculation abnormalities in systemic sclerosis: a prospective study to evaluate the role of non-invasive tests
INTRODUCTION: Microcirculation dysfunction is a typical feature of systemic sclerosis (SSc) and represents the earliest abnormality of primary myocardial involvement. We assessed coronary microcirculation status by combining two functional tests in SSc patients and estimating its impact on disease outcome.
METHODS: Forty-one SSc patients, asymptomatic for coronary artery disease, were tested for coronary flow velocity reserve (CFR) by transthoracic-echo-Doppler with adenosine infusion (A-TTE) and for left ventricular wall motion abnormalities (WMA) by dobutamine stress echocardiography (DSE). Myocardial multi-detector computed tomography (MDCT) enabled the presence of epicardial stenosis, which could interfere with the accuracy of the tests, to be excluded. Patient survival rate was assessed over a 6.7- ± 3.5-year follow-up.
RESULTS: Nineteen out of 41 (46%) SSc patients had a reduced CFR (≤2.5) and in 16/41 (39%) a WMA was observed during DSE. Furthermore, 13/41 (32%) patients showed pathological CFR and WMA. An inverse correlation between wall motion score index (WMSI) during DSE and CFR value (r = -0.57, P <0.0001) was observed; in addition, CFR was significantly reduced (2.21 ± 0.38) in patients with WMA as compared to those without (2.94 ± 0.60) (P <0.0001). In 12 patients with abnormal DSE, MDCT was used to exclude macrovasculopathy. During a 6.7- ± 3.5-year follow-up seven patients with abnormal coronary functional tests died of disease-related causes, compared to only one patient with normal tests.
CONCLUSIONS: A-TTE and DSE tests are useful tools to detect non-invasively pre-clinical microcirculation abnormalities in SSc patients; moreover, abnormal CFR and WMA might be related to a worse disease outcome suggesting a prognostic value of these tests, similar to other myocardial diseases
Aerospace medicine and biology: A continuing bibliography with indexes, supplement 218, April 1981
This bibliography lists 161 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1981
Predictors of cardiac events after major vascular surgery: Role of clinical characteristics, dobutamine echocardiography, and beta-blocker therapy
CONTEXT: Patients who undergo major vascular surgery are at increased risk
of perioperative cardiac complications. High-risk patients can be
identified by clinical factors and noninvasive cardiac testing, such as
dobutamine stress echocardiography (DSE); however, such noninvasive
imaging techniques carry significant disadvantages. A recent study found
that perioperative beta-blocker therapy reduces complication rates in
high-risk individuals. OBJECTIVE: To examine the relationship of clinical
characteristics, DSE results, beta-blocker therapy, and cardiac events in
patients undergoing major vascular surgery. DESIGN AND SETTING: Cohort
study conducted in 1996-1999 in the following 8 centers: Erasmus Medical
Centre and Sint Clara Ziekenhuis, Rotterdam, Twee Steden Ziekenhuis,
Tilburg, Academisch Ziekenhuis Utrecht, Utrecht, and Medisch Centrum
Alkmaar, Alkmaar, the Netherlands; Ziekenhuis Middelheim, Antwerp,
Belgium; and San Gerardo Hospital, Monza, Istituto di Ricovero e Cura a
Carattere Scientifico, San Giovanni Rotondo, Italy. PATIENTS: A total of
1351 consecutive patients scheduled for major vascular surgery; DSE was
performed in 1097 patients (81%), and 360 (27%) received beta-blocker
therapy. MAIN OUTCOME MEASURE: Cardiac death or nonfatal myocardial
infarction within 30 days after surgery, compared by clinical
characteristics, DSE results, and beta-blocker use. RESULTS: Forty-five
patients (3.3%) had perioperative cardiac death or nonfatal myocardial
infarction. In multivariable analysis, important clinical determinants of
adverse outcome were age 70 years or older; current or prior angina
pectoris; and prior myocardial infarction, heart failure, or
cerebrovascular accident. Eighty-three percent of patients had less than 3
clinical risk factors. Among this subgroup, patients receiving
beta-blockers had a lower risk of cardiac complications (0.8% [2/263])
than those not receiving beta-blockers (2.3% [20/855]), and DSE had
minimal additional prognostic value. In patients with 3 or more risk
factors (17%), DSE provided additional prognostic information, for
patients without stress-induced ischemia had much lower risk of events
than those with stress-induced ischemia (among those receiving
beta-blockers, 2.0% [1/50] vs 10.6% [5/47]). Moreover, patients with
limited stress-induced ischemia (1-4 segments) experienced fewer cardiac
events (2.8% [1/36]) than those with more extensive ischemia (>/=5
segments, 36% [4/11]). CONCLUSION: The additional predictive value of DSE
is limited in clinically low-risk patients receiving beta-blockers. In
clinical practice, DSE may be avoided in a large number of patients who
can proceed safely for surgery without delay. In clinically intermediate-
and high-risk patients receiving beta-blockers, DSE may help identify
those in whom surgery can still be performed and those in whom cardiac
revascularization should be considered
Methodology, feasibility, safety and diagnostic accuracy of dobutamine stress echocardiography
Large numbers of patients referred for evaluation of chest pain are unable to perform adequate, diagnostic exercise testing. In these patients, dobutamine stress echocardiography (DSE) represents an alternative, exercise- independent stress modality. Apart from the ~5% of patients with an inadequate acoustic window, 10% of patients referred for this test have nondiagnostic (sub-maximal negative) test results. Serious side effects during or shortly after DSE are uncommon, with ventricular fibrillation or myocardial infarction occurring in ~1 of 2,000 studies. No deaths have been reported. On the basis of a total number of 2,246 patients, reported in 28 studies, the sensitivity, specificity and accuracy of the test for the detection of coronary artery disease (CAD) were 80%, 84% and 81%, respectively. Mean sensitivities for one-, two- and three-vessel disease were 74%, 86% and 92%, respectively. The sensitivity for detection of disease in the left circumflex coronary artery (55%) was lower, both compared with that for left anterior descending (72%) and right coronary artery disease (76%). The sensitivity of predicting multivessel disease by multiregion echocardiographic abnormalities varied widely, from 8% to 71%. In direct comparisons, DSE was superior to exercise electrocardiography and dipyridamole echocardiography and comparable to exercise echocardiography and radionuclide imaging. DSE is a useful, feasible and safe exercise-independent stress modality for assessing the presence, localization and extent of CAD
Stress echocardiography for the risk stratification of patients following coronary bypass surgery
Objectives: The aim of the study was to assess the prognostic value of stress echocardiography after surgical revascularization. Methods: We evaluated 500 (100 women) patients who had undergone exercise or pharmacological SE after a median of 69 months after coronary artery by-pass grafting (CABG). Of these, 351 (70%) complained of symptoms suggestive of ischemic origin while 149 (30%) were tested for asymptomatic progression of the disease. Results: SE was positive for ischemia in 196 (39%) patients. During a median follow-up of 25 months, 61 patients died, 33 had a nonfatal myocardial infarction, and 112 underwent late (N3 months) revascularization. Multivariable Cox\u27 regression analysis indicated age (HR=1.04; 95% CI 1.01-1.06; pb0.003), and peak WMSI (HR=3.07; 95% CI 1.96-4.81; p=0.0001) as independent predictors of hard (total mortality and myocardial infarction) events. SE information provided a significant improvement in predictive power of the statistical model (chi-square increase 34%, pb0.0001 for hard and 91%, pb0.0001 for major events, respectively). Survival analysis showed ischemia at SE to be associated with significantly higher hard and major event rate in both symptomatic and asymptomatic patients. Discussion: SE represents an effective tool for the risk stratification of patients with previous CABG independently of the presence of symptoms suggestive of ischemic origin
Noninvasive Imaging for the Assessment of Coronary Artery Disease
Noninvasive cardiac imaging is a cornerstone of the diagnostic work-up in patients with suspected coronary artery disease (CAD), cardiomyopathy, heart failure, and congenital heart disease. It is essential for the assessment of CAD from functional and anatomical perspectives, and is considered the gate-keeper to invasive coronary angiography. Cardiac tests include exercise electrocardiography, single photon emission computed tomography myocardial perfusion imaging, positron emission tomography myocardial perfusion imaging, stress echocardiography, coronary computed tomography angiography, and stress cardiac magnetic resonance. The wide range of imaging techniques is advantageous for the detection and management of cardiac diseases, and the implementation of preventive measures that can affect the long-term prognosis of these diseases. However, clinicians face a challenge when deciding which test is most appropriate for a given patient. Basic knowledge of each modality will facilitate the decision-making process in CAD assessment
Doppler tissue imaging in ST-elevation myocardial infarction
Highly available, noninvasive and cost-effective, echocardiography remains a keystone in
the evaluation of patients with coronary artery disease (CAD). Echocardiographic
assessment of cardiac function at rest and during dobutamine stress has direct clinical
implications. Conventional echocardiographic parameters however, are partly based on
visual interpretation of cardiac motion, thereby subject to interobserver variability,
especially in patients with poor image quality. As a complement, myocardial velocity
imaging techniques such as Doppler tissue imaging (DTI) offer quantitative markers of
cardiac function.
In the present study, we explored the feasibility and diagnostic value of DTI in the
evaluation of left and right ventricular function, the presence of inducible ischemia and
myocardial viability in patients with ST-elevation myocardial infarction (STEMI).
In 90 patients with STEMI (64 men and 26 women aged 65±13 years) echocardiography
was performed at day 1, 5–7 days and 6 months after admission. At day 5–7, dobutamine
stress echocardiography (DSE) with wall motion analysis (WMA) was performed,
followed by coronary angiography within 24 hours. Using DTI, systolic, early and late
diastolic myocardial velocities were recorded near the mitral annulus at 4 left ventricular
(LV) sites, and near the tricuspid annulus in the right ventricular free wall. The myocardial
performance index (MPI), a Doppler-based, combined measure of systolic and diastolic
function, was calculated as the sum of the isovolumic time intervals divided by the ejection
time derived from DTI at the 4 LV sites. Forty-one aged-matched healthy subjects served
as controls.
In patients with complete normalization of conventional parameters of LV function at
follow-up, peak systolic as well as early diastolic LV myocardial velocities were
significantly reduced compared with those in healthy subjects, possibly reflecting a
residual subendocardial damage.
Using peak systolic velocity in the right ventricular (RV) free wall as a marker of RV
function, sensitivity and specificity of DTI in identifying patients with electrocardographic
signs of RV infarction (ST-elevation in ECG lead V4R) were 89% and 71%, respectively.
Furthermore, peak RV systolic velocities remained reduced in patients with RV infarction,
even after resolution of ECG changes and were still evident at 6 months’ follow-up.
Use of the MPI as a marker of ischemia during DSE was shown to be feasible, and
although the majority of patients did not achieve an optimal level of stress, relative
changes in MPI between rest and peak stress offered reasonable diagnostic properties,
superior to those of WMA. Sensitivity and specificity for detection of left anterior
descending, left circumflex and right coronary artery disease were 80% and 87%, 59% and
80% and 85% and 72%, respectively.
Finally, we found that MPI during low-dose dobutamine infusion exhibits a specific
pattern, similar to that of WMA, predicting late recovery of LV systolic function.
In conclusion, the use of DTI during echocardiography at rest and during dobutamine
stress is feasible and allows evaluation of LV and RV function in the acute as well as the
late phase after a STEMI. Furthermore, changes in MPI derived from DTI during DSE
identify patients with residual CAD and predict late recovery of LV function,
independently of age, troponin level and time to reperfusion treatment
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