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ABSTRACT: Cell therapy for myocardial disease is a rapidly progressive field. However, present strategies of cell transplantation into the infarcted myocardium have limitations from practical points of view. One of the biggest challenges is to achieve a sufficient number of suitable cells. Umbilical cord blood (UCB), an unlimited source of stem/progenitor cells that could be used for transplantation into the injured heart, is readily available. The aim of our review is to describe the potential and prospect of UCB as a new supplier of cells for myocardial repair. The use of UCB stem cells might be of importance to elderly and sick people in whom the availability of autologous stem cells is limited.
Cytotherapy 02/2005; 7(3):251-7. · 3.63 Impact Factor
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A A Kotlyar,
Z Vered,
I Goldberg, P Chouraqui,
D Nas,
E Fridman,
Z Chen-Levy,
S Fytlovich,
G Sangiorgi,
L G Spagnoli,
A Orlandi,
N Savion,
M Eldar,
M Scheinowitz
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ABSTRACT: Insulin-like growth factors (IGF) I and II improve myocardial function after coronary occlusion in different animal models.
To investigate the mechanism of improved myocardial function after administration of IGF-I or IGF-II in acute myocardial infarction.
Female pigs (mean (SD) weight 25 (5) kg) were subjected to acute myocardial infarction by microembolisation with 75-150 micrometer affigel blue beads. The beads contained and slowly released 150 microgram/pig of IGF-I (n = 6), IGF-II (n = 6), or pig albumin (n = 6). Echocardiography, perfusion imaging, and haemodynamic measurements were performed before infarction and during four weeks after infarction. Regional wall motion of different left ventricular segments was scored semiquantitatively on the basis of a three point scoring system, from normal = 0 to dyskinesia = 3. Serum cardiac troponin I concentration was measured before, immediately after, and three hours after the infarct. Excised hearts were analysed for actin, desmin, blood vessel density, and DNA laddering within the infarct, border, and normal myocardial areas.
Myocardial function of the infarct related area improved significantly during the four weeks of follow up in both the IGF groups (p = 0.01). Myocardial perfusion, heart rate, and blood pressure were similar in all the animals during the study. Treated animals had lower serum cardiac troponin I concentration (p = 0.001), more actin in the border area (p = 0.01) and infarct area (p = 0.0001), and reduced DNA laddering in the infarct area compared with the controls (p < 0.05). IGF groups had more blood vessels in the border area (p = 0.04) and the infarct area (p = 0.003).
Both types of IGF improved myocardial function and the improvement was associated with preservation of myocardial structure. IGF-I was more effective than IGF-II.
Heart (British Cardiac Society) 12/2001; 86(6):693-700. · 4.22 Impact Factor
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The American Journal of Cardiology 09/2000; 86(4):462-4. · 3.37 Impact Factor
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ABSTRACT: This study evaluated the diagnostic value of dipyridamole plus low level treadmill exercise (dipyridamole stress) thallium-201 single-photon emission computed tomography (SPECT) in patients taking antianginal drugs.
Dipyridamole stress is the major substitute for maximal exercise in patients referred for myocardial perfusion imaging. Although antianginal drugs are commonly suspended before exercise, dipyridamole stress is usually performed without discontinuing these drugs.
Twenty-six patients underwent two dipyridamole perfusion studies: the first without (SPECT-1) and the second with (SPECT-2) antianginal treatment. Twenty-one patients (81%) received calcium antagonists, 19 (73%) received nitrates, and 8 (31%) received beta-blockers. Eighteen of the patients underwent coronary angiography. Data are presented as the mean value +/- SD.
Visual scoring yielded significantly larger and more severe reversible perfusion defects for SPECT-1 than for SPECT-2. Quantitative analysis showed larger perfusion defects on stress images of SPECT-1 in the left anterior descending coronary artery (LAD) (25 +/- 21% vs. 17 +/- 15%, p = 0.003), left circumflex coronary artery (LCx) (56 +/- 35% vs. 48 +/- 36%, p = 0.03) and right coronary artery (RCA) (36 +/- 27% vs. 25 +/- 24%, p = 0.008) territories. Individual vessel sensitivities in the LAD, LCx and RCA territories were 93%, 79% and 100% for SPECT-1 and 64%, 50% and 70% for SPECT-2, respectively. These differences were highly significant for the LAD (p = 0.004) and LCx (p = 0.00004) territories. The overall individual vessel sensitivity of SPECT-1 was significantly higher than that of SPECT-2 (92% vs. 62%, p = 0.000003). Specificity was not significantly different in SPECT-1 compared with SPECT-2 (80% and 93%, p = 0.33).
Continued use of antianginal drugs before dipyridamole plus low level treadmill exercise thallium-201 SPECT may reduce the extent and severity of myocardial perfusion defects, resulting in underestimation of coronary artery disease.
Journal of the American College of Cardiology 07/1998; 31(7):1540-6. · 14.16 Impact Factor
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ABSTRACT: This study was designed to examine whether ST segment elevation in posterior chest leads (V7 to V9) during acute inferior myocardial infarction (MI) identifies patients with a concomitant posterior infarction and whether these patients might benefit more from thrombolysis.
Because the posterior wall is faced by none of the 12 standard electrocardiographic (ECG) leads, the ECG diagnosis of posterior infarction is problematic and has often remained undiagnosed, especially in the acute phase.
Eighty-seven patients with a first inferior infarction who were treated with recombinant tissue-type plasminogen activator were stratified according to the presence (Group A [46 patients]) or absence (Group B [41 patients]) of concomitant ST segment elevation in posterior chest leads V7 to V9.
Patients in Group A had a higher incidence of posterolateral wall motion abnormalities (p < 0.001) on radionuclide ventriculography, a larger infarct area (as evidenced by higher peak creatine kinase levels) (p < 0.02) and a lower left ventricular ejection fraction (LVEF) at hospital discharge (p < 0.008) than those in Group B. ST segment elevation in leads V7 to V9 was associated with a higher incidence of at least one of the following adverse clinical events: reinfarction, heart failure or death (p = 0.05). Although patency of the infarct-related artery (IRA) in Group A resulted in an improved LVEF at discharge (p < 0.012), LVEF was unchanged in Group B, regardless of the patency status of the IRA.
ST segment elevation in leads V7 to V9 identifies patients with a larger inferior MI because of concomitant posterolateral involvement. Such patients might benefit more from thrombolytic therapy.
Journal of the American College of Cardiology 03/1998; 31(3):506-11. · 14.16 Impact Factor
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ABSTRACT: The aim of this study was to test the influence of the source decay on the performance of the attenuation-corrected (AC) thallium-201 ((<sup>2</sup>01)Tl) single photon emission tomography using a gadolinium-153 (<sup>153</sup>Gd) line source. Three acquisitions were performed using the same line source during a period of 26 months. The activity of the source was 300 mCi for the first acquisition and 30 mCi for the last one. For each phantom acquisition AC and NC (non-corrected) <sup>201</sup>Tl SPECT was performed. AC and NC images were evaluated by a 31-segment semiquantitative analysis. Comparisons between the circumferential count density profiles of the AC and NC segmented polar map were done. Evident degradation in the AC performance was demonstrated for line source activity lower then 60 mCi. From noise propagation the authors estimated that source activity higher then 300 mCi would give poor improvement in the AC performance
Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE; 02/1998
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ABSTRACT: Only one third of hospitalized patients with acute myocardial infarction (AMI) receive thrombolytic therapy despite its proven benefits on outcomes. Elderly patients, have a greater risk of death during myocardial infarction; however, thrombolytic therapy appears to be less used in these patients, as compared to the general AMI-patients. In order to evaluate the impact of magnesium supplementation in AMI-patients without thrombolytic therapy, 194 patients participated in a prospective, randomized and placebo-controlled study: 96 patients received a 48-hour intravenous magnesium sulfate and 98 isotonic glucose as placebo. Magnesium infusion reduced the incidence of arrhythmias, congestive heart failure and in-hospital-mortality compared with placebo (27 vs. 40%, p = 0.04; 18 vs. 23%, p = 0.27; 4 vs. 17%, p < 0.01, respectively); in the subgroup of elderly patients (> 70 years), the benefit was also obvious (42 vs. 50%; 18 vs. 25%; 9 vs. 23%, p = 0.09, respectively). These data suggest that intravenous magnesium supplementation might be justified in order to reduce myocardial damage and mortality rate in subsets of high-risk patients such the elderly and/or patients not suitable for thrombolysis. Additional trials appear to be indicated to evaluate the potential benefit of magnesium in well defined specific subsets of AMT-patients.
Herz 06/1997; 22 Suppl 1:73-6. · 0.92 Impact Factor
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ABSTRACT: Thrombolytic therapy reduces in-hospital mortality. However, 70% to 80% of patients do not receive thrombolysis and their in-hospital mortality is high. During the last decade some clinical trials demonstrated that magnesium sulfate reduced in-hospital mortality. The aim of this study was to evaluate the effects of magnesium sulfate in patients with acute myocardial infarction (AMI) who were considered unsuitable for thrombolytic therapy. Intravenous magnesium sulfate was evaluated in 194 patients with AMI ineligible for thrombolytic therapy in a randomized, double-blind, placebo-controlled study. Group I consisted of 96 patients who received 48-hour intravenous magnesium. Group II consisted of 98 patients who received isotonic glucose as a placebo. Magnesium reduced the incidence of arrhythmias, congestive heart failure, and conduction disturbances compared with placebo (27% vs 40%, p = 0.04; 18% vs 23%, p = 0.27; 10% vs 15%, p = 0.21, respectively). Left ventricular ejection fraction 72 hours and 1 to 2 months after admission was higher in patients who received magnesium sulfate than in those taking placebo (49% vs 43% and 52% vs 45%; p = 0.01, respectively). In-hospital mortality was significantly reduced in patients receiving magnesium sulfate than in those receiving placebo (4% vs 17%; p < 0.01), and also in the subgroup of elderly patients (> 70 years) (9% vs 23%; p = 0.09). In conclusion, magnesium sulfate should be considered as an alternative therapy to thrombolysis in patients with AMI.
The American Journal of Cardiology 03/1995; 75(5):321-3. · 3.37 Impact Factor
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ABSTRACT: Iodine-123-iodophenyl-9-methyl-pentadecanoic acid [( 123I]MPDA) and thallium-201 (201Tl) were sequentially injected in 11 patients during exercise-induced myocardial ischemia. Simultaneous dual-energy planar images were obtained at 5 min, 3 and 5 hr. All studies were concordantly either positive (8/11) or negative (3/11) by both radionuclides. Exact agreement for segmental uptake was 93%, 94% and 94% for 5-min, 3- and 5-hr images, respectively. Exact agreement for defect reversibility by 3 and 5 hr were 95% and 92%. The initial defect contrasts and myocardial-to-lung ratios were similar by both agents but myocardial-to-liver ratio was lower by [123I]MPDA at 5 min, which became similar to 201Tl at 5 hr. Normal percent myocardial clearances of both agents were comparable and significantly higher than those in defect zones. Thus [123I]MPDA is suitable for myocardial imaging and correlates closely with 201Tl for initial postexercise myocardial uptake and defect reversibility. Defect reversibility appears to result from differential myocardial clearance from normal and ischemic regions.
Journal of Nuclear Medicine 04/1991; 32(3):447-52. · 6.38 Impact Factor
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ABSTRACT: The occurrence and significance of transient dilation of the left ventricle during dipyridamole stress-redistribution thallium-201 scintigraphy was studied in 73 patients who underwent both dipyridamole thallium-201 study and coronary angiography. Transient dilation ratio was calculated from planar anterior images by dividing the computer-derived left ventricular area on the initial image by that of the 4-hour image. In 11 patients with normal coronary arteriograms or less than 50% coronary stenosis, the transient dilation ratio was 0.98 +/- 0.046. An abnormal transient dilation ratio was defined as greater than or equal to 1.12, representing greater than or equal to 3 standard deviations above the mean normal value. When the 15 patients with an abnormal ratio were compared with the 58 with a normal ratio, the former group had a significantly higher frequency of 3 critical (greater than or equal to 90%) coronary stenoses (33 vs 5%), higher prevalence of collaterals (67 vs 24%), more extensive myocardial reversible defects by planar (71 vs 10%) or by single-photon emission computed tomography (87.5 vs 35%) imaging and a higher incidence of dipyridamole-induced anginal chest pain (53 vs 22%). No significant difference between the 2 groups was noted with respect to age, gender, prior myocardial infarction, single or double critical coronary stenosis, dipyridamole-induced ischemic electrocardiographic response and increased lung uptake. An abnormal transient dilation ratio of greater than or equal to 1.12 was a specific marker of multivessel (87%) or 3-vessel (85%) critical coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)
The American Journal of Cardiology 10/1990; 66(7):689-94. · 3.37 Impact Factor
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ABSTRACT: The utility of stress-redistribution thallium-201 myocardial perfusion single-photon emission computed tomography (SPECT) in patients with a prior single myocardial infarction was studied in 66 patients who were tested by both SPECT and coronary angiography. SPECT was quantified by comparing the patients' circumferential count profiles to a previously established normal data base and by plotting the results onto a polar coordinate map that localized defects to the 3 major coronary artery territories. The pattern of reversibility of the quantitatively detected defects was assessed by consensus visual analysis. SPECT thallium-201 detected myocardial infarction in 62 of 66 patients (sensitivity = 94%). Sixty-five percent of the infarct zones showed some reversibility at 4-hour imaging which corresponded with angiographic evidence of flow to the infarct zones in 95.5% of cases. Late (18 to 24 hours) imaging, done in 26 patients, showed complete or partial reversibility of 29% of infarct zone segments which were nonreversible on 4-hour images. To improve specificity for detection of disease in coronary arteries supplying the non-infarct territories, new quantitative criteria were developed that took into consideration contiguity of defects with the infarct zone. Accuracy for detection of patients with multivessel coronary disease by quantitative thallium-201 SPECT was 86%, which was significantly higher than those of the clinical response to exercise (48%), the exercise electrocardiographic response (56%) or their combination (65%).(ABSTRACT TRUNCATED AT 250 WORDS)
The American Journal of Cardiology 08/1990; 66(2):151-7. · 3.37 Impact Factor
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ABSTRACT: Isosorbide-5-mononitrate was administered in a continuous intravenous infusion, according to the haemodynamic response, to 19 patients with left heart failure of ischaemic aetiology; 12 with acute heart failure complicating an acute myocardial infarction and 7 with chronic ischaemic failure. In both groups, the following statistically significant haemodynamic changes were observed: a decrease in PCWP from 25.4 +/- 4.6 to 17.2 +/- 4.6 mmHg; an increase in SWI from 19.1 +/- 10 to 23.6 +/- 13.1 gm m-2; a slight increase in cardiac index with no change in arterial pressure and only minimal decrease in vascular resistance. There were two major differences in the haemodynamic response between the patients with acute heart failure and those with chronic disease: (a) the duration of the effect of isosorbide-5-mononitrate on the PCWP was longer in the first group (mean, 8 hours, compared to 1.5 hours in the chronic group), and (b) the effect on afterload was more pronounced in the group with chronic ischaemic failure than in the first group. Thus, isosorbide-5-mononitrate administered by intravenous infusion under careful monitoring appears to have a beneficial role in the treatment of acute as well as chronic ischaemic heart failure.
European Heart Journal 02/1988; 9 Suppl A:175-80. · 10.48 Impact Factor
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ABSTRACT: Isosorbide-5-mononitrate (ISMN), the main metabolite of isosorbide dinitrate (ISDN) was recently introduced in clinical use. The hemodynamic effects of oral ISMN and ISDN, administered in equal doses, were studied in a randomized, crossover fashion in 20 patients with pump failure of ischemic etiology. Baseline hemodynamic criteria for admission into the study were: pulmonary capillary wedge pressure (PCW) of at least 20 mmHg and systolic arterial pressure (AP) above 90 mmHg. Hemodynamic parameters were serially measured and systemic vascular resistance was calculated up to 6 h postadministration of either ISMN or ISDN single dose (40 mg). Maximal effects obtained were statistically significantly different from baseline. While ISMN and ISDN appeared to be equipotent in reducing the filling pressure, with a maximum effect reached in 60-120 min, the mononitrate maintained its effects for a longer period.
Clinical Cardiology 11/1987; 10(10):603-8. · 2.15 Impact Factor
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ABSTRACT: To evaluate the influence of two techniques of myocardial protection on septal wall motion (SWM) and left ventricular ejection fraction, 21 patients with a normal SWM underwent surgery using either conventional antegrade cardioplegia (group I, n = 9) or combined antegrade/retrograde cardioplegia (group II, n = 12). The patients were assessed pre- and postoperatively by radionuclide ventriculography. A resting thallium-201 study was performed in patients (n = 6) with a postoperatively abnormal SWM: in 2 of 9 (22%) in group I and in 4 of 12 (33%) in group II (p = NS). The left ventricular ejection fraction was similar in both groups before surgery (57 +/- 3% in group I vs. 57 +/- 8% in group II; p = NS) and did not change significantly after surgery. All 6 patients with an abnormal SWM had a normal septal thallium-201 uptake. Thus, (1) an abnormal SWM after cardiac surgery is common: (2) it is not due to perioperative ischemia or infarction, and (3) neither the incidence of an abnormal SWM not the global left ventricular function is influenced by the addition of retrograde cardioplegia during open heart surgery.
Cardiology 88(6):526-9. · 1.71 Impact Factor
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ABSTRACT: In this era of cost constraints in health care and the growing demand for cost-effective clinical strategies, the nuclear cardiologist is under increasing pressure to show clear evidence that myocardial imaging studies compete favorably with other modalities. This underlines the need for ensuring consistently high image quality and accuracy using optimally chosen standardized protocol. Nuclear medicine imaging has not yet reached the level of standardization, automation, and built-in quality control of imaging modalities such as ultrasound or x-ray computerized tomography, where the press of a button guarantees a consistent high-quality image. This is due to the large number of parameters and other factors affecting image quality that each individual operator still has to choose or be aware of before commencing imaging. Of crucial importance is ensuring the correct collection of the raw data. Processing can be repeated, but errors in the raw data, if detected at all, require repeating the entire study. These errors can cause artifacts that are difficult or impossible to recognize and are the major causes of incorrect reporting. Examples are a poorly prepared radiopharmaceutical, a poor injection, scatter from "hot" areas outside myocardium, an undetected change in the photopeak window, uniformity, or center of rotation, insufficient acquisition time, camera too far from the patient, etc. The first step to guarantee consistent image quality and accuracy is the preparation and strict implementation of a quality assurance program covering all the individual stages of the procedure starting from preparation of the radiopharmaceutical and ending with processing, display, and reporting. The next step is the standardization of optimally chosen protocols with maximization of automation. Rapid built-in automated software-driven equipment quality control checks should be developed. Finally, attenuation and scatter correction, gated single-photon emission computed tomography, and the advent of digital cameras will no doubt improve quantitation and accuracy even further following clinical evaluation in close cooperation with manufacturers who have the incentive to accelerate all the above steps.
Journal of Nuclear Cardiology 3(2):157-66. · 2.67 Impact Factor
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ABSTRACT: Image artifacts caused by nonuniform photon attenuation are a source of error in interpretation of images during myocardial perfusion single photon emission computed tomography (SPECT). A newly introduced attenuation correction method was evaluated for improvement in image homogeneity during 201Tl SPECT. The method was assessed with a cardiac phantom and in examinations of 42 patients (29 men) with a low likelihood of coronary disease.
Simultaneous transmission-emission SPECT was performed with a moving collimated 153Gd line source synchronized with a moving electronic acquisition window for transmission imaging and a novel variable-width electronic exclusion window for emission imaging designed to avoid transmission-to-emission cross talk. The resulting uncorrected and corrected polar maps were analyzed visually and divided into 31 segments for quantitative analysis. Visual analysis of the color-coded mean polar maps showed clear improvement in homogeneity after correction among the phantom, male patients, female patients, and 42 patients combined at stress and redistribution. The male and female mean polar maps showed very little differences in regional count distribution after correction. Quantitative analysis of the mean polar maps showed the following mean segmental counts (%SD) before and after attenuation correction: phantom 88 (9) to 90 (7.5), P = .00005; men at stress 83 (10) to 88 (6), P = .0007, and at redistribution 84 (8) to 88 (6), P = .01; women at stress 86 (7) to 90 (5), P = .0002, and at redistribution 87 (5) to 88 (7), P = .3; patients combined at stress 84 (8) to 88 (6), P = .0004, and at redistribution 85 (7) to 87 (7), P = .03. Inferior/anterior count ratio for men at stress increased after correction from 0.82 to 0.99 and septal/lateral count ratio from 0.94 to 1.02. Inferior/anterior count ratio for men at redistribution increased from 0.86 to 1.06 and septal/lateral count ratio from 0.97 to 1.04. Inferior/anterior count ratio for women at stress increased from 0.95 to 1.03 and septal/lateral count ratio from 0.93 to 1.00. Inferior/anterior count ratio for women at redistribution increased from 1.04 to 1.10, and septal/lateral count ratio decreased from 1.02 to 1.00.
Improvement in image homogeneity was demonstrated with this attenuation correction method with a cardiac phantom and for patients with low likelihood of coronary artery disease. The slight relative increase in inferior wall counts at redistribution was most likely caused by scatter from the relatively higher liver activity compared with the situation during stress and emphasizes the need for scatter correction. The close similarity in count distribution for the mean male and female polar maps supports use of a sex-independent normal database for quantitative analysis. The reduced variation in corrected images from patient to patient implies increased accuracy for detection of myocardial defects.
Journal of Nuclear Cardiology 5(4):369-77. · 2.67 Impact Factor
