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Biomedical subjects

A Battler

Publications and source records attributed to A Battler.

At least 37 records · Page 2Linked to original sources
PubMed2001

The effects of streptokinase and hydroxyethyl starch on in vitro clot disruption by ultrasound.

BACKGROUND: In vitro studies showed that low-frequency ultrasound (US) causes blood clot dissolution. This effect is augmented with thrombolytics, microbubbles and microparticles. However, in animal models of transcutaneous delivery, US alone is not effective, probably due to attenuation of US energy by overlying skin. When combined with thrombolytics or microbubbles, transcutaneous US is highly effective. PURPOSE: To assess the synergistic effect of low-intensity low-frequency US and saline, hydroxyethyl starch (HAES) (a non-gas filled microparticle containing solution), streptokinase (STK), and their combination on blood clot disruption. METHODS: Human blood clots from 4 healthy donors, 2-4 hours old, were immersed for 0, 15, or 30 min in 37 degrees C in 10 ml of the above-mentioned solutions, and then were randomized to 10 sec of 20 kHz US or no US. The % difference in weight was calculated. RESULTS: Immersion for 30 min without US resulted in 13.8 +/- 1.2% clot lysis in saline, and 22.0 +/- 1.3%, 21.7 +/- 2.1%, and 23.2 +/- 1.9% in STK, HAES, and STK + HAES, respectively (p = 0.002). US augmented clot lysis in all groups and at all time points. With low-intensity US, HAES was not better than saline. However, the combination of HAES + STK with US resulted in larger clot disruption at 15 sec incubation time (46.7 +/- 3.2%) than with saline (29.6 +/- 2.1%), HAES (29.6 +/- 2.5%), and STK (32.8 +/- 3.6%) (p < 0.001). CONCLUSION: low-frequency, low-intensity US combined with HAES and STK resulted in greater clot disruption at short incubation times. This combination may assist in achieving faster reperfusion in in vivo models.

Blood↗
PubMed2001

Management and outcome of cardiogenic shock complicating acute myocardial infarction in hospitals with and without on-site catheterisation facilities.

OBJECTIVE: To determine whether the availability of on-site catheterisation and revascularisation facilities influenced hospital management and outcome of patients with acute myocardial infarction complicated by cardiogenic shock. METHODS: Patients with acute myocardial infarction were enrolled prospectively in four nationwide surveys during 1992, 1994, 1996, and 1998. The characteristics, management, and outcome of patients with cardiogenic shock were compared between hospitals with on-site catheterisation facilities (group 1; 18 hospitals) and without such facilities (group 2; 8 hospitals). RESULTS: Of 5351 patients with acute myocardial infarction, 254 (4.7%) developed cardiogenic shock. Group 1 patients (n = 186 of 3854; 4.6%) were younger (mean (SD) age, 69.6 (12) v 73.7 (10) years, p = 0.006) and had a lower proportion of women (36% v 52%, p = 0.03) than group 2 (n = 68 of 1243; 5.2%). There was no difference in other characteristics including the use of thrombolysis. Group 1 patients more often underwent coronary angiography (26% v 4%, p < 0.001), angioplasty (21% v 4%, p = 0.002), and intra-aortic balloon counterpulsation (28% v 4%, p < 0.001). Seven day mortality was lower among group 1 than among group 2 patients (61% v 77%, p = 0.02), even after age and sex adjustment (odds ratio (OR) 0.54; 95% confidence interval (CI) 0.28 to 1.02). This outcome benefit persisted at 30 days (74% v 88%, p = 0.01; OR 0.45, 95% CI 0.18 to 0.98), and at 6 months (80% v 90%, p = 0.06; OR 0.57, 95% CI 0.22 to 1.33). CONCLUSIONS: The greater use of invasive and interventional procedures in hospitals with catheterisation facilities is associated with improved survival of patients with acute myocardial infarction complicated by cardiogenic shock. Immediate availability of invasive care facilities will improve the outcome of cardiogenic shock in the community setting.

Aged↗
PubMed2001

Aspirin and percutaneous coronary angioplasty are associated with a decline in mortality from cardiogenic shock. Results from a national Israeli survey, 1992--1998.

BACKGROUND AND METHODS: Despite the significant progress in the care and outcome of patients with acute myocardial infarction (AMI), the impact of evolving therapies on the incidence and outcome of patients with cardiogenic shock complicating AMI has been questioned. We analyzed trends in the incidence, care and outcome of cardiogenic shock from four national surveys conducted during 1992--1998. RESULTS: Of the 5,351 AMI patients admitted to all coronary care units in Israel, 254 (4.7%) developed cardiogenic shock. The incidence of cardiogenic shock decreased over time (5.8, 5.1, 4.3 and 4.4% for the years 1992, 1994, 1996 and 1998, respectively, p = 0.08). Concomitantly, there was an increase in utilization of coronary angiography, urgent angioplasty and intra-aortic balloon counterpulsation. In addition, there was an increase in hospital use of aspirin, nitrates, ACE inhibitors and beta-blockers. Patients with shock were more likely to die within 7 days compared with AMI patients not having shock (65 vs. 4%; p < 0.001). During the study period, the mortality of patients with shock decreased: at 7 days (72% in 1992 to 60% in 1998; p = 0.09), at 30 days (87 to 70%, respectively; p = 0.01) and at 6 months (89 to 77%, respectively; p = 0.02). Both aspirin and angioplasty were independently associated with improved outcome after adjustment for baseline characteristics and study period. CONCLUSIONS: Although the mortality rate of cardiogenic shock complicating AMI remains high, the increased utilization of aspirin and angioplasty is associated with improved outcome.

Aged↗
PubMed2000

Relation of nonobstructive aortic valve calcium to carotid arterial atherosclerosis.

Recently it was shown that subjects with aortic valve calcium (AVC) are at increased risk for future cardiovascular disease including stroke. We hypothesized that the increased risk of stroke may be due to an association with carotid artery atherosclerotic disease. Between 1995 and 1999 our laboratory made a diagnosis of AVC without significant stenosis in 3,949 patients. Of those, 279 patients without other cardiac structural exclusion criteria (148 men and 131 women; mean age 73 +/- 9 years, range 45 to 90) underwent carotid artery duplex ultrasound for various indications, and formed the study group. Age- and sex-matched patients without AVC (n = 277), who underwent carotid artery duplex ultrasound during the same period and for the same indications, served as the control group. Compared with the control group, the AVC group had a significantly higher prevalence of carotid stenosis (> 40% to 60%, 89% vs 78% [p < 0.001]; >60% to 80%, 43% vs 23% [p <0.001];and > 80% to 100%, 32%vs 14% [p < 0.001]). The AVC group had a similar, significantly higher prevalence of > or = 2-vessel disease and bilateral carotid stenosis (stenosis levels of > 20% to 40%, >40% to 60%, > 60% to 80%, and > 80% to 100%). In multivariate analysis, AVC, but not traditional risk factors, was the only independent predictor of severe carotid atherosclerotic disease (stenosis > 80% to 100%; p = 0.0001). Thus, there is a significant association between the presence of AVC and carotid atherosclerotic disease.

Aged↗
PubMed2000

Bioengineered cardiac grafts: A new approach to repair the infarcted myocardium?

BACKGROUND: The myocardium is unable to regenerate because cardiomyocytes cannot replicate after injury. The heart is therefore an attractive target for tissue engineering to replace infarcted myocardium and enhance cardiac function. We tested the feasibility of bioengineering cardiac tissue within novel 3-dimensional (3D) scaffolds. METHODS AND RESULTS: We isolated and grew fetal cardiac cells within 3D porous alginate scaffolds. The cell constructs were cultured for 4 days to evaluate viability and morphology before implantation. Light microscopy revealed that within 2 to 3 days in culture, the dissociated cardiac cells form distinctive, multicellular contracting aggregates within the scaffold pores. Seven days after myocardial infarction, rats were randomized to biograft implantation (n=6) or sham-operation (n=6) into the myocardial scar. Echocardiography study was performed before and 65+/-5 days after implantation to assess left ventricular (LV) remodeling and function. Hearts were harvested 9 weeks after implantation. Visual examination of the biograft revealed intensive neovascularization from the neighboring coronary network. Histological examination revealed the presence of myofibers embedded in collagen fibers and a large number of blood vessels. The specimens showed almost complete disappearance of the scaffold and good integration into the host. Although control animals developed significant LV dilatation accompanied by progressive deterioration in LV contractility, in the biograft-treated rats, attenuation of LV dilatation and no change in LV contractility were observed. CONCLUSIONS: Alginate scaffolds provide a conducive environment to facilitate the 3D culturing of cardiac cells. After implantation into the infarcted myocardium, the biografts stimulated intense neovascularization and attenuated LV dilatation and failure in experimental rats compared with controls. This strategy can be used for regeneration and healing of the infarcted myocardium.

Alginates↗
PubMed2000

Nonobstructive aortic valve calcium as a window to atherosclerosis of the aorta.

Aortic valve calcium without stenosis and mitral annulus calcium (MAC) are known to correlate with atherosclerotic risk factors. Recently, it has been reported that MAC is associated with atherosclerosis of the cardiovascular system, suggesting MAC as an atherosclerotic process by itself. Hence, the aim of the present study was to determine whether a similar association between aortic valve calcium and aortic atheroma exists. Ninety-six patients (54 men and 42 women, mean age 72 +/- 12 years) with aortic valve calcium who underwent transesophageal echocardiography (TEE) formed the study group. They were compared with 92 sex- and age-matched patients without aortic valve calcium who underwent TEE for the same indications during the same period. The presence and echocardiographic features of aortic atheromas were evaluated by TEE. No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the aortic valve calcium group for prevalence of aortic atheroma (86% vs 30%, p = 0.001). This significant trend was also consistent with the dimension and complexity of the atheromas. On multivariate analysis aortic valve calcium, and MAC were the only independent predictors of aortic atheroma (p = 0.0001, 0.006 respectively). We conclude that there is a significant association between the presence of aortic valve calcium and the presence and severity of aortic atheroma. Thus, aortic valve calcium may serve as a window to atherosclerosis of the aorta.

Aged↗
PubMed2000

Microparticle-containing oncotic solutions augment in-vitro clot disruption by ultrasound.

Echocardiographic contrast agents enhance blood clot disruption by ultrasound. It has been suggested that the microbubbles add nuclei for the enhancement of cavitation by ultrasound. However, microbubbles are rapidly destroyed by the ultrasound energy. We assessed whether non-gas filled colloidal solutions (hyperoncotic medium molecular hydroxyethyl starch and degraded gelatin polypeptides) will facilitate clot disruption by ultrasound. In two separate experiments human blood clots, 200-400 mg in weight, were weighed and then immersed for 15 seconds in 10 ml normal saline solution containing 0%, 0.1%, 1%, 2%, and 5% of hyperoncotic medium molecular hydroxyethyl starch or 0%, 0.035%, 0.175%, 0.35%, and 0.7% degraded gelatin polypeptides. Clots were randomized to 10 seconds 20 kHz ultrasound or immersion without ultrasound. After treatment, the clots were reweighed, and the percent difference in weight was calculated. Non-gas filled microparticle-containing solutions such as hyperoncotic medium molecular hydroxyethyl starch and degraded gelatin polypeptides significantly augmented blood clot disruption by ultrasound. The effect is dependent on the colloidal solution concentration with maximal effect achieved with 1% hyperoncotic medium molecular hydroxyethyl starch and 0.35% degraded gelatin polypeptides.

Blood Coagulation↗
PubMed2000

[Thrombolytic therapy or primary coronary angioplasty in acute myocardial infarction? Israel Thrombolytic Survey Group].

There has been continuous debate over the superiority of primary percutaneous, transluminal, coronary angioplasty (PTCA) over thrombolysis for acute myocardial infarction (AMI). It was questioned whether this advantage of primary PTCA reported in selected populations by experienced centers can be replicated in our clinical practice. We compared demographic and clinical variables, therapies and outcome in AMI treated with primary PTCA vs thrombolytic therapy. Clinical and demographic variables of 1,678 unselected AMI patients (admitted January/February and May/July 1996) were analyzed in 16 cardiac care units with on-site catheterization facilities and ability to perform PTCA. Of these 803 (48%) were treated by thrombolysis and 99 (6%) by primary PTCA. The prevalence of adverse prognostic variables, such as anterior wall MI, heart failure on admission or during hospital stay, pulmonary edema, and ventricular tachycardia or fibrillation, was higher in the PTCA group. The 7-day, 30-day and 1-year mortality rates were similar in the 2 groups: 4%, 7.2% and 12.8%, respectively, in the PTCA group and 5%, 7.2% and 11.1% in the thrombolysis group. There was a trend toward lower mortality in subgroups of high-risk patients: those with heart failure on admission (Killip class > 1), the elderly (> 65 years), and those with previous MI treated with PTCA. After adjusting for confounders, treatment with primary PTCA was not found to be associated with lower mortality. Only a small proportion of AMI patients in Israel were treated with primary PTCA in 1996. The frequency of adverse prognostic factors among them was higher but their short and long term outcomes were similar to those of high risk patients treated with thrombolysis.

Aged↗
PubMed2000

Cytotoxic T lymphocytes are activated following myocardial infarction and can recognize and kill healthy myocytes in vitro.

The damage of myocardial infarction (MI) is often progressive. A possible mechanism for subsequent myocardial damage and heart failure after MI is immune response against cardiac self-antigens. The purpose of our study was to test the hypothesis that cytotoxic T lymphocytes are activated following acute MI and may have a role in producing further myocardial damage. Rats were allocated into three experimental groups: acute MI, Sham MI and non-operated control. One, two and three weeks after surgery, lymphocytes were obtained from rat spleens and incubated with neonatal cardiac myocytes. Lymphocyte proliferation was assessed by a thymidine incorporation assay and calculated as proliferation index (PI). Myocyte destruction was measured by a crystal-violet staining assay and expressed as percentage of cell destruction. Proliferation index was significantly higher among lymphocytes obtained from MI animals (44. 3+/-5.8 and 44.9+/-5.1, at 2 and 3 weeks after MI, respectively) than sham MI (29.3+/-5.3, 27.1+/-4.7) (P<0.05) or control animals (17.1+/-2.5, 16.2+/-2.8) (P=0.03). Cytotoxic activity of the MI lymphocytes against the cultured cardiomyocytes was significantly higher 2 and 3 weeks after MI, (36.4+/-7.3%, 69.3+/-4.9%) compared to sham MI (17.9+/-3.14%, 36.6+/-5.3%) (P<0.001) and control animals respectively (13.3+/-5.4%, 17.4+/-6.1%) (P<0.001). The cytotoxic activity against healthy cardiomyocytes was myocyte-specific, induced by CD8 lymphocytes and major-histocompatibility complex (MHC) restricted. Cytotoxic T lymphocytes (CD8) are activated following MI and can recognize and kill normal cardiomyocytes in vitro. The newly described pathophysiological insights may provide novel oportunities to prevent death of non-ischemic cardiomyocytes and heart failure following myocardial infarction.

Animals↗
PubMed2000

Platelet glycoprotein IIb/IIIa blockade and outcome of cardiogenic shock complicating acute coronary syndromes without persistent ST-segment elevation.

OBJECTIVES: The study examined whether antiplatelet treatment with eptifibatide affected the frequency and outcome of shock among patients in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial who had acute coronary syndromes but not persistent ST-segment elevation. BACKGROUND: Preliminary reports suggest a salutary effect of antiplatelet agents when shock complicates acute myocardial infarction. METHODS: We analyzed the impact of antiplatelet treatment with eptifibatide on the frequency and outcome of cardiogenic shock developing after enrollment. PURSUIT was a double-blind, randomized trial that examined the efficacy of eptifibatide (180 microg/kg bolus + continuous infusion of 2.0 microg/kg/min for < or =96 h) versus placebo among patients who had acute coronary syndromes but not persistent ST-segment elevation. RESULTS: Shock developed in 2.5% of the 9,449 patients at a median (25th, 75th interquartiles) of 94.0 (38, 206) h. Death by 30 days occurred in 65.8% of shock patients. Patients who had acute myocardial infarction upon enrollment had a greater incidence of shock (2.9% vs. 2.1%, p = 0.01), developed shock earlier (40.2% <48 h vs. 20.9%, p = 0.001), and had higher 30-day mortality from shock (77.2% vs. 52.7%, p = 0.001). Randomization to eptifibatide did not affect the occurrence of shock (p = 0.71, adjusted odds ratio [OR] = 0.95, 95% confidence interval [CI] = 0.72-1.25). However, shock patients treated with eptifibatide had significantly reduced adjusted odds of 30-day death (p = 0.03, adjusted OR = 0.51, 95% CI = 0.28-0.94). CONCLUSIONS: Patients with shock treated with eptifibatide had significantly reduced adjusted odds of death, suggesting a salutary effect of antiplatelet therapy on shock. This finding warrants verification in specifically designed studies.

Aged↗
PubMed2000

Cardiogenic shock: single center experience with and without on-site catheterization facilities.

BACKGROUND: The beneficial effect of on-site catheterization facilities on the survival of all patients with myocardial infarction complicated by cardiogenic shock has been questioned. Our objective was to evaluate the impact of the availability of on-site catheterization facilities on the outcome of unselected patients with cardiogenic shock. METHODS AND RESULTS: We studied the hospital records of 70 consecutive patients with cardiogenic shock admitted to our intensive coronary care unit during 1990-1996, and compared two groups of patients: those admitted before (n = 34) and after (n = 36) the opening of our catheterization laboratory. Patients admitted when the catheterization laboratory was available were of similar age, but included fewer males and fewer patients with prior myocardial infarction. Following the activation of the catheterization laboratory, utilization rates of coronary angiography, percutaneous transluminal coronary angioplasty and intra-aortic balloon pump increased, compared with the previous period. However, there was no improvement in in-hospital (88 vs. 83%; p = 0.7) and 30-day mortality (91 vs. 86%; p = 0.7) before versus after the activation of our catheterization laboratory. Twelve patients selected to cardiac catheterization (9 underwent percutaneous transluminal coronary angioplasty) experienced lower in-hospital and 30-day mortality compared with patients who were not selected (58 vs. 96, and 67 vs. 96%, respectively; p < 0.02). CONCLUSIONS: Following the activation of the catheterization laboratory, the mortality of the entire population of cardiogenic shock patients remained relatively unchanged. Still, a small subgroup of these patients selected for urgent cardiac catheterization had a lower mortality compared with patients who were not selected.

Aged↗
PubMed2000

Correlation between the admission electrocardiogram and regional wall motion abnormalities as detected by echocardiography in anterior acute myocardial infarction.

We correlated ST elevation in various leads on admission and regional dysfunction in 132 patient with first anterior acute myocardial infarction using echocardiography. ST elevation in leads I and a VL and II, III and aVF was not associated with a specific pattern of regional dysfunction. Basal anterior and septal regional dysfunction were seen more often in patients with ST elevation in V1 (49 vs. 25%, p = 0.006; 35 vs. 17%, p = 0.048, respectively). Patients with ST elevation in V2 had more regional dysfunction of the apical inferior region (84 vs. 53%; p = 0.01). ST elevation in V5 and V6 was not associated with more apical or lateral wall motion abnormalities. ST elevation in lead V1 in anterior myocardial infarction is associated with a high incidence of regional dysfunction of the basal anterior, anteroseptal and septal regions.

Aged↗
PubMed1999

Contribution of stenting to the results of rescue PTCA.

Failed thrombolysis in acute myocardial infarction (AMI) is associated with increased mortality. Controversial benefit of rescue percutaneous transluminal coronary angioplasty (PTCA) in these setting has been published. The feasibility, safety, and contribution of stenting to the outcome of AMI patients treated with this strategy is unknown. We studied the angiographic result and clinical outcome of 33 patients with failed thrombolysis referred for rescue angioplasty. Twenty-three patients had stenting and 10 patients did not have stenting. Both groups had similar clinical and angiographic characteristics. Stent indications were nonoptimal result, 40%; bailout, 40%; elective, 20%. Angiographic success was 100% with stent vs. 91% with balloon alone (P < 0.8). Postprocedure residual stenosis was 1.5% (0%-10%) with stent vs. 18.05% (0%-30%) with balloon alone (P < 0.01). Thirty-day outcome with and without stent was mortality, 0% vs. 13% (P < 1.0); reinfarction, 10% vs. 0% (P < 0.30); target vessel revascularization, 0% vs. 21% (P < 0.21). The 6-month mortality was 0% with stent vs. 14% (P < 0.5). We conclude that stenting during rescue angioplasty is feasible, safe, and is associated with better immediate angiographic results. Although no obvious clinical benefit was found, a potential decrease in the revascularization rate was suggested.

Angioplasty, Balloon, Coronary↗
PubMed1999

Aspirin and mortality in patients treated with angiotensin-converting enzyme inhibitors: a cohort study of 11,575 patients with coronary artery disease.

OBJECTIVES: The purpose of this study was to investigate the significance of the possible negative interaction between aspirin and angiotensin-converting enzyme (ACE) inhibitors. BACKGROUND: Several provocative reports have recently suggested that aspirin is unsafe in patients with heart failure and has negative interaction with ACE inhibitors that might attenuate their beneficial effects upon survival. METHODS: We analyzed mortality data of 11,575 patients with coronary artery disease screened for the Bezafibrate Infarction Prevention trial. A total of 1,247 patients (11%) were treated with ACE inhibitors. Of them, 618 patients (50%) used aspirin. RESULTS: Five-year mortality was lower among patients on ACE inhibitors and aspirin than patients on ACE inhibitors without aspirin (19% vs. 27%; p < 0.001). After adjusting for confounders, treatment with aspirin and ACE inhibitors remained associated with lower mortality risk than using ACE inhibitors only (relative risk [RR] = 0.71; 95% confidence interval [CI] = 0.56 to 0.91). Subgroup analysis of 464 patients with congestive heart failure treated with ACE inhibitors revealed 221 patients (48%) on aspirin and 243 patients not on aspirin. Although clinical characteristics and therapy were similar, patients taking aspirin experienced lower mortality than patients who did not (24% vs. 34%; p = 0.001). After adjustment, treatment with aspirin was still associated with lower mortality (RR = 0.70; 95% CI = 0.49 to 0.99). CONCLUSIONS: Among coronary artery disease patients with and without heart failure who are treated with ACE inhibitors, the use of aspirin was associated with lower mortality than treatment without aspirin. Our findings contradict the claim that aspirin attenuates the beneficial effect of ACE inhibitors and supports its use in patients with coronary artery disease treated with ACE inhibitors.

Angiotensin-Converting Enzyme Inhibitors↗