Prognostic utility of cardiovascular magnetic resonance upright maximal treadmill exercise testing.

BACKGROUND: Left ventricular wall motion abnormalities (LVWMA) observed during cardiovascular magnetic resonance (CMR) pharmacologic stress testing can be used to determine cardiac prognosis, but currently, information regarding the prognostic utility of upright maximal treadmill induced LVWMA is unknown. Our objective was to determine the prognostic utility of upright maximal treadmill exercise stress CMR. METHODS: One hundred and fifteen (115) men and women with known or suspected coronary arteriosclerosis and an appropriate indication for cardiovascular (CV) imaging to supplement ST segment stress testing underwent an upright treadmill exercise CMR stress test in which LVWMA were identified before and immediately after exercise. Personnel blinded to results determined the post-test incidence of cardiac events (cardiac death, myocardial infarctions [MI], and unstable angina warranting hospital admission or coronary arterial revascularization). RESULTS: All participants completed the testing protocol, with 90% completing image acquisition within 60 s of exercise cessation. MI or cardiac death occurred in 3% of individuals without and 17% of individuals with inducible LVWMA (p = 0.024). The combination of MI, cardiac death, and unstable angina warranting hospitalization occurred in 14% of individuals without and 47% of individuals with inducible LVWMA (p = 0.002). The addition of CMR imaging identified those at risk for future events (p = 0.002), as opposed to the electrocardiogram stress test alone (p = 0.63). CONCLUSIONS: In patients with or suspected of coronary arteriosclerosis and appropriate indication for imaging to supplement ST segment analysis during upright treadmill exercise, the presence of inducible LVWMA during treadmill exercise stress CMR supplements ST segment monitoring and helps identify those at risk of the future combined endpoints of myocardial infarction, cardiac death, and unstable angina warranting hospitalization.

Intra-coronary bone marrow mononuclear cell transplantation in patients with ST-elevation myocardial infarction: a randomized controlled study.

BACKGROUND: Stem cell transplantation is a potential treatment to improve left ventricular ejection fraction (LVEF) after ST elevation myocardial infarction (STEMI). However, the outcomes still are controversial. OBJECTIVE: To determine the 6-month LVEF of the patients who underwent intra-coronary bone marrow mononuclear cell (BMC) transplantation in patients with STEMI compared with controlled subjects. MATERIAL AND METHOD: After successful percutaneous coronary intervention (PCI) in STEMI patients who had LVEF was less than 50% were randomized to intra-coronary BMC transplantation or control. Bone marrow aspiration of 100 cc was performed in the morning. After cellprocessing for three hours, the suspension of BMC about 10 cc were infused to infracted area using standard PCI technique. Balloon occlusion for three minutes was performed during cell infusion. Cardiac magnetic resonance imaging was used to determine LVEF scar volume and LV volume before and six-month follow-up. RESULTS: Between September 2006 and July 2008, 23patients (11 in BMC group and 12 in control group) were enrolled. Mean BMC count before transplant was 420 x 10(6) cell with 96% viability. At six-month follow-up, New York Heart Association function class significantly improved in both groups (2.3 +/- 0.6 to 1.2 +/- 0. 4 for BMC and 2.3 +/- 0.7 to 1.3 +/- 0.5 for control group) but no difference was seen between groups. However, scar volume, wall motion score index, and LVEF did not show improvement after six months in both groups (33.7 +/- 7.7 to 33.5 +/- 7.6 for BMC and 31.1 +/- 7.1 to 32.6 +/- 8.3 for control group). No complication was observed during the procedure. CONCLUSION: BMC transplantation intra-coronary in patients with STEMI in KCMH was feasible and safe but LVEF improvement could not be demonstrated.

Transcoronary infusion of bone marrow derived multipotent stem cells to preserve left ventricular geometry and function after myocardial infarction.

BACKGROUND: Myocardial damage after myocardial infarction (MI) was deemed irreversible after late reperfusion. Administration of multipotent stem cell (MSC) into such infarct may regenerate the myocardium and capillary network. HYPOTHESIS: Transcoronary infusion of bone marrow derived multipotent stem cells into infarcted related artery after acute myocardial infarction is feasible, safe and improve left ventricular function. METHODS: We conducted a pilot study in patients who survived ST-elevation MI with late reperfusion therapy and remained hemodynamically stable. Bone marrow derived MSC was infused into a patent infarct-related coronary artery during brief low pressure (2 atm) balloon inflation. A 3-T gadolinium-based MRI was performed at baseline and 8 weeks later to evaluate infarct area and LV function. RESULTS: We enrolled 10 patients, age 63.8 +/- 2.8 years 5.2 +/- 4.12 x 10(6) MSC were infused via coronary artery 24.8 +/- 16 days after infarction. The procedures were successful in all patients without any in-hospital event. Infarct size by MRI decreased by 5.84% (P = .018) over 8 weeks. Mean baseline left ventricular ejection fraction (LVEF) was 44.1% +/- 9% and was 46.3% +/- 9% at 8 weeks (P = .34). A trend of smaller LV end-systolic volume with 65.02 +/- 18.2 ml vs 63.04 +/- 21.89 ml (P = .09) with no change of LV end-diastolic volume observed. CONCLUSION: MSC infusion into coronary circulation was feasible and safe after myocardial infarction. Infarct size was reduced with preservation of LV geometry.

Location of arterial stiffening differs in those with impaired fasting glucose versus diabetes: implications for left ventricular hypertrophy from the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: To determine whether middle-aged and older individuals with impaired fasting glucose (IFG), but no clinical evidence of cardiovascular disease, exhibit abnormal changes in proximal thoracic aortic stiffness or left ventricular (LV) mass when compared with healthy counterparts. RESEARCH DESIGN AND METHODS: From the Multi-Ethnic Study of Atherosclerosis, 2,240 subjects with normal fasting glucose (NFG), 845 with IFG, and 414 with diabetes, all aged 45 to 85 years and without preexisting coronary artery disease, underwent MRI determinations of total arterial and proximal thoracic aortic stiffness and LV mass. The presence or absence of other factors known to influence arterial stiffness was assessed. RESULTS: After adjustment for clinical factors known to modify arterial stiffness, proximal thoracic aortic stiffness was not increased in those with IFG compared with those with NFG (1.90 +/- 0.05 versus 1.91 +/- 0.04 10(-3) mmHg(-1), respectively, P = 0.83). After accounting for clinical factors known to influence LV mass, LV mass was increased in those with diabetes relative to those with NFG (150.6 +/- 1.4 versus 145.8 +/- 0.81 g, P < 0.0009) but not in those with IFG in comparison with NFG (145.2 +/- 1.03 versus 145.8 +/- 0.81 g, P = 0.56). CONCLUSIONS: Middle-aged and older individuals with the pre-diabetes state of IFG do not exhibit abnormal proximal thoracic distensibility or LV hypertrophy relative to individuals with NFG. For this reason, an opportunity may exist in those with IFG to prevent LV hypertrophy and abnormal aortic stiffness that is observed in middle-aged and older individuals with diabetes.

Feasibility and safety of intra-coronary bone marrow mononuclear cell transplantation in ST elevation myocardial infarction patients.

BACKGROUND: Stem cell transplantation is a potential treatment to improve left ventricular ejection fraction (LVEF) after ST elevation myocardial infarction (STEMI). However technique and mode of transplantation, type of cells, number of cells, and when to transplant are still unknown. OBJECTIVE: To determine the feasibility and safety of bone marrow mononuclear cell (BMC) intra-coronary transplantation and 6-months results in patients with STEMI. MATERIAL AND METHOD: After successful percutaneous coronary intervention (PCI) in STEMI patients who did not have flow re-established within 12 hours and poor LVEF (less than 50%) by echocardiography were enrolled Bone marrow aspiration of 100 cc was performed in the morning. After cell processing for 3 hours, the suspension of BMC about 10 cc were infused to infarcted area using standard PCI technique. Balloon occlusion for 3 minutes was performed during cell infusion. Cardiac magnetic resonance imaging was used to determine LVEF scar volume and LV volume before and 6 months after transplantation. RESULTS: Five patients were enrolled between May and August 2006. Duration of STEMI before transplantation ranged from 18 days to 14 years. Total amount of BMC ranged from 67 x 10(6) to 335 x 10(6). Number of CD 34 and CD 133+ cells were approximation to be 0.7 x 10(6) to 7.7 x 10(6) and 0.01 x 10(6) to 3.04 x 10(6). LVEF was increased from 36.4 at baseline to 43.3 at 6-month. NT pro-BNP level was decreased from 1105 ng/ml at baseline to 288 pg/ml at 6-month. No complications such as chest pain, no re-flow phenomenon, ventricular arrhythmia, or hypotension was detected during the procedure. CONCLUSION: Intra-coronary BMC transplantation in patients with STEMI in our center is feasible and safe. LVEF was slightly improved; however, a randomized controlled study is needed.

Detection of coronary stenoses in chronic stable angina by multi-detector CT coronary angiography.

OBJECTIVE: To assess the accuracy for detection of coronary stenoses in chronic stable angina patients. MATERIAL AND METHOD: Twenty-four chronic stable angina patients, referred for conventional coronary angiography by the indication of positive stress tests or clinical highly suspicion of coronary artery disease were enrolled. MDCT coronary angiography (MDCTCA) and conventional coronary angiography (144 coronary vessels) were performed within one month. Accuracy of MDCTCA for predicting significant coronary artery stenoses was analyzed. RESULTS: Five patients were excluded due to the total Agaston calcium score more than 500. Therefore, 114 vessels or 209 segments from 19 patients (9 males and 10 females) were available for analysis, and 186 segments were assessable (89%). Of all assessable segments, 13 from 20 significant lesions (65%) and 158 from 167 normal or non-significant lesions (95%) were correctly detected by MDCTCA. The sensitivity, specificity, positive and negative predictive values to detect significant coronary artery stenoses in terms of vessel are 82%, 96%, 79%, and 97% respectively. CONCLUSION: Coronary CT angiography provides accurate assessment of coronary luminal artery narrowing and shows the ability to exclude significant coronary artery stenoses in patients with chronic stable angina.

Left ventricular spherical remodeling and apical myocardial relaxation: cardiovascular MR imaging measurement of myocardial segments.

PURPOSE: To prospectively evaluate left ventricular (LV) shape and regional relaxation to determine if rapid, early relaxation of the LV is lost with spherical remodeling of the LV. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review board. All participants gave written informed consent. Cardiovascular magnetic resonance (MR) imaging and transthoracic echocardiography (TTE) were performed in 18 individuals. Each participant was classified into one of three groups according to LV shape and TTE-derived mitral filling parameters. Pairwise comparisons of cardiovascular MR imaging measurements of LV relaxation were made between healthy individuals and those with spherically shaped LVs. RESULTS: The LV regional relaxation rates were determined in a total of 108 basal, middle, and apical myocardial segments in 18 participants (13 women, five men; age range, 35-76 years). Participants with a spherically shaped LV (sphericity index, <1.5) and a mitral inflow velocity E wave/A wave ratio of less than 1.0 exhibited apical thinning velocities that were lower than those of healthy individuals (sphericity index, > or =1.5) (P < .01). The ratio of LV relaxation velocities in the apical versus middle LV segments correlated significantly with sphericity index (R(2) = 0.53; P = .0005). CONCLUSION: LV apical relaxation velocities in participants with LV spherical remodeling (sphericity index, <1.5) were reduced compared with those of healthy individuals (sphericity index, > or =1.5).

Reliability of the evaluation for left ventricular ejection fraction by ECG-gated multi-detector CT (MDCT): comparison with biplane cine left ventriculography.

OBJECTIVE: To evaluate the reliability of measurement for left ventricular ejection fraction (LVEF) by ECG-gated multi-detector CT (MDCT) comparing with biplane cine left ventriculography that is current gold standard. MATERIAL AND METHOD: The authors reviewed the data from 15 patients who were referred for coronary CT angiography for clinical indications and underwent cardiac catheterization within 14 days. Coronary CTA studies were performed on MDCT Somatom Sensation 16, Siemens, Germany, Slice thickness 1 mm, Slice collimation 0. 75 mm, and Pitch 0. 3. L VEF were measured with MDCTby Simpson s method and compared with values measured by biplane area length method from cardiac catheterization. The L VEF from both techniques were compared using intraclass correlation power analysis (SPSS analysis software). RESULTS: The study population consisted with six men and nine women with a mean age of 54+/-10 years. The LVEF measured from MDCT and cine ventriculography were 54.7 +/-10% and 56. 3+/-10%, respectively. LVEF measured with MDCT by interpreter I and interpreter 2 was significantly correlated with L VEF measured with biplane cine ventriculography (ICC= 0.99 and 0.98, respectively). The interobserver reliability was excellent with ICC = 0.9. CONCLUSION: LVEF measurement with MDCT during coronary CT angiography can be performed easily, very accurately, and compare well with measures taken from biplane cine left ventriculography.

Dobutamine stress magnetic resonance imaging.

Measurements of left ventricular function with cardiovascular magnetic resonance (CMR) at rest and during intravenous dobutamine are useful for identifying myocardial ischemia, viability, and the risk of subsequent cardiovascular events. Without ionizing radiation, intravascular iodinated contrast administration, or acoustic window limitations, CMR has emerged as a useful adjunct to transthoracic echocardiography for assessing patients with or suspected of having coronary artery disease.

Comprehensive assessment of a post-coronary bypass graft patient with cardiovascular magnetic resonance imaging and multi-detector computed tomography / 老年心脏病学杂志（英文版）

Coronary bypass graft surgery (CABG) is a revascularization procedure which reduces myocardial ischemia and cardiovascular morbidity and mortality in selected patients; however, up to 40% of saphanous vein grafts may degenerate over 10 years. Although coronary angiography is the gold standard to detect graft patency and native vessel disease, sometimes it is difficult to locate the grafts resulting in increased exposure to radiation and contrast administration. This case highlights the utility of cardiac computerized tomography and magnetic resonance imaging to provide comprehensive noninvasive assessment in a patient post CABG.

Cardiovascular examination with 3.0 Tesla magnetic resonance imaging: first 100 cases at Ramathibodi Hospital.

BACKGROUND: Cardiovascular magnetic resonance imaging (CMR) has been utilized for diagnosis in various cardiovascular diseases and most of those were performed on a 1.5 Tesla CMR system. Recently, a 3.0 Tesla magnetic resonance imaging system has been introduced into clinical practice, however the clinical experience on cardiovascular examination using this system is limited. Therefore, the authors' institution has integrated a team for developing a CMR program on this 3.0 Tesla system. OBJECTIVE: To describe the authors' experience on the 3.0 Tesla CMR system. MATERIAL AND METHOD: The data on patients referred to the authors' CMR unit between August 2004 and October 2005 were reviewed. RESULTS: One hundred patients were referred for CMR examination. The mean age was 56 years (2 month - 85 years) and 65 patients were male. The most common indication was to assess coronary artery disease (64 patients). The performed examination was divided into cardiac structure and function assessment (39%), stress testing (23%), coronary magnetic resonance angiography (13%), myocardial viability assessment (12%), magnetic resonance angiography (9%), and flow assessment (4%). CONCLUSION: The present study highlights that comprehensive assessment of various cardiovascular diseases can be performed on the 3.0 Tesla CMR system.

Cardiac CT angiography: comprehensive assessment of patient suspected coronary artery disease.

Coronary artery disease is the leading cause of mortality and morbidity worldwide. Although coronary angiography is currently a gold standard for diagnosis of coronary artery disease, some patients are of concern regarding small but not negligible risk of complications and discomfort of the procedure. In recent years, cardiac computerized tomographic angiography (CTA) is an attractive non-invasive modality for evaluation of chest pain in patients suspected to have coronary artery disease. The authors report a 61 year-old-man with a history of hypertension and hypercholesterolemia who presented with exertional angina pectoris for 3 weeks. Cardiac CTA was performed and revealed a severely stenotic lesion at the proximal left anterior descending coronary artery (LAD) with left ventricular ejection fraction of 53% and hypokinesia of anteroseptal and apical wall. The patient then was planned and underwent percutaneous coronary interventional procedure. This case highlights the utility of comprehensive information from cardiac CTA as a modality for coronary interventional procedure planning.

Effect of the transmural extent of myocardial scar on left ventricular systolic wall thickening during intravenous dobutamine administration.

Using magnetic resonance imaging, the extent of scar tissue due to chronic infarction and quantification of dobutamine systolic wall thickening (SWT) can be measured simultaneously in human subjects. To determine whether the transmural extent of scar tissue determines dobutamine SWT in chronic ischemic heart disease, we assessed the transmural extent of hyperenhancement and dobutamine SWT with magnetic resonance imaging in 16 patients. The transmural extent of hyperenhancement correlated inversely with dobutamine SWT (r = -0.7, p <0.001). All segments with dobutamine SWT >/=2 mm showed a transmural extent of hyperenhancement of <50%.

Inducible left ventricular outflow tract gradient during dobutamine stress echocardiography: an association with intraoperative hypotension but not a contraindication to liver transplantation.

BACKGROUND: Dobutamine stress echocardiography (DSE) is frequently used in the evaluation of cardiac risk prior to orthotopic liver transplantation (OLT). In the general cardiac population, an inducible left ventricular outflow tract gradient (LVOT Delta) during DSE has variable prognostic importance. The purpose of this study was to determine the prevalence and clinical significance of LVOT Delta in patients undergoing OLT during DSE. METHODS: Consecutive medical records of 106 patients who had undergone OLT at our institution from January 1997 until January 2002 were retrospectively analyzed and divided into two groups based on the presence (Group I, LVOT Delta >36 mmHg) or absence (Group II, LVOT Delta< or = 36 mmHg) of a significant LVOT Delta measured during DSE. We determined any outcome differences between these two groups with regard to intraoperative hypotension, cardiac mortality, length of hospital stay, graft function, and renal function post-OLT. RESULTS: Forty-six patients had an LVOT Delta > 36 mmHg (Group I) and 60 patients had LVOT Delta< or = 36 mmHg (Group II). Baseline demographics were similar in both groups. There was no significant overall difference in cardiac mortality between Group I versus Group II patients (0 versus 1 patient, respectively, P=0.57). Intraoperative hypotension occurred in 4 patients in Group I versus 0 patient in Group II (P=0.03). Length of stay, graft function, and postoperative renal function were similar in both groups. CONCLUSION: A significant LVOT Delta >36 mmHg is a frequent finding occurring in 46/106 (43%) of patients who have DSE pre-OLT. Intraoperative hypotension is associated with patients having an LVOT Delta. However, post-OLT patients with significant LVOT Delta have a similar in-hospital outcome compared to patients without significant LVOT Delta.

Relation of cardiac prognosis to segment location with apical left ventricular ischemia.

Previously, we have shown that myocardial ischemia induced during intravenous dobutamine in the distal segments composing the left ventricular apex is associated with a heightened risk of future myocardial infarction or cardiac death. In this study, we find this heightened risk is present independent of the location of the distal segment within the left ventricular apex.

Feasibility to detect severe coronary artery stenoses with upright treadmill exercise magnetic resonance imaging.

We performed treadmill exercise magnetic resonance imaging in 27 patients with exertional chest pain who were referred for contrast coronary angiography to determine the feasibility of this method to identify severe coronary artery stenoses. The sensitivity and specificity for detecting >70% coronary artery luminal diameter narrowings on contrast coronary angiography were 79% and 85%, respectively.

Assessment of cardiac function with MR imaging.

A variety of black or white blood imaging techniques are available for assessing global and regional LV and RV function during cardiovascular MR imaging examinations. In addition to providing information about LV function at rest, these techniques provide diagnostic and prognostic information regarding myocardial ischemia and viability during MR imaging stress tests.

Detection of pseudoaneurysm of the left ventricle by fast imaging employing steady-state acquisition (FIESTA) magnetic resonance imaging.

This report highlights the importance of interpretating images throughout the course of a dobutamine MRI stress test. Upon review of the baseline images, the left ventricular (LV) endocardium was not well seen due to flow artifacts associated with low intracavitary blood-flow velocity resulting from a prior myocardial infarction. Physicians implemented a cine fast imaging employing steady-state acquisition (FIESTA) technique that was not subject to low flow artifact within the LV cavity. With heightened image clarity, physicians unexpectedly identified a LV pseudoaneurysm.

Magnetic resonance imaging assessment of cardiac function.

Measurements of left ventricular function at rest and during stress are useful for identifying myocardial ischemia, injury, and the risk of subsequent myocardial infarction. Without ionizing radiation or intravascular contrast administration, magnetic resonance imaging techniques can be used to acquire precise measurements of left ventricular function. This relatively new development may enhance a physician's ability to provide care to patients with cardiovascular disease.