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Biomedical subjects

D Hasdai

Publications and source records attributed to D Hasdai.

At least 73 records · Page 4Linked to original sources
PubMed1997

The changing face of coronary interventional practice. The Mayo Clinic experience.

BACKGROUND: Devices designed to facilitate or replace conventional percutaneous transluminal coronary angioplasty have been introduced in recent years. OBJECTIVES: To characterize the changes in percutaneous coronary interventional practice over 16 years and to assess the relative use of these new devices. METHODS: We performed a retrospective analysis of all patients who underwent percutaneous coronary revascularization at Mayo Clinic, Rochester, Minn, during a 16-year period (1980-1995) and characterized the changes in procedural and clinical factors. RESULTS: The number of coronary interventional procedures performed increased from 38 in 1980 to 1284 in 1995. Atherectomy and laser angioplasty were incorporated in 1988; their use peaked in 1994 (17% of procedures) but decreased to 9.9% by 1995. In contrast, the use of intracoronary stents has increased steadily since 1990. By 1995, intracoronary stents were placed in 48.2% of procedures. The success rate improved from 55.3% in 1980 to 91.4% in 1995, although patients were older (51 +/- 10 [mean +/- SD] years in 1980 vs 63 +/- 12 years in 1995), had more extensive coronary artery disease (0% with multivessel disease in 1980 vs 47.4% in 1995), had more complex lesions, and often underwent intervention in the peri-infarction setting (2.6% of procedures in 1980 vs 17% in 1995). The rate of referral to emergency coronary bypass surgery after percutaneous procedures declined from 5.2% in 1980 to 0.4% in 1995. CONCLUSIONS: Current coronary interventional practice is expanding and improving. In contrast to intracoronary stents that have greatly affected current practice, other new devices are used infrequently. Conventional angioplasty, with or without intracoronary stents, remains the dominant treatment strategy.

Adult↗
PubMed1997

Effect of smoking status on the long-term outcome after successful percutaneous coronary revascularization.

BACKGROUND: Cigarette smoking is known to be deleterious to patients with coronary artery disease, but the effect of smoking on the clinical outcome of percutaneous coronary revascularization is unknown. METHODS: Patients who had undergone successful percutaneous coronary revascularization at the Mayo Clinic between 1979 and 1995 were divided into nonsmokers (n=2009), former smokers (those who had stopped smoking before the procedure, n=2259), quitters (those who stopped smoking after the procedure, n=435), and persistent smokers (those who smoked before and after the procedure, n=734). RESULTS: The maximal follow-up was 16 years (mean [+/-SD], 4.5+/-3.4). The nonsmokers and former smokers had similar base-line characteristics and outcomes. The quitters and persistent smokers were younger than the nonsmokers and former smokers and had more favorable clinical and angiographic characteristics. In analyses adjusted for confounding base-line characteristics, the persistent smokers had a greater relative risk of death (1.76 [95 percent confidence interval, 1.37 to 2.26]) and of Q-wave infarction (2.08 [95 percent confidence interval, 1.16 to 3.72]) than the nonsmokers. The quitters and persistent smokers were less likely than the nonsmokers to undergo additional percutaneous coronary procedures (relative risk, 0.80 [95 percent confidence interval, 0.64 to 0.98] and 0.67 [95 percent confidence interval, 0.56 to 0.81], respectively) or coronary bypass surgery (relative risk, 0.72 [95 percent confidence interval, 0.54 to 0.95] and 0.68 [95 percent confidence interval, 0.54 to 0.86], respectively). The persistent smokers were also at greater risk for death than the quitters (relative risk, 1.44 [95 percent confidence interval, 1.02 to 2.11]). CONCLUSIONS: Patients who continued to smoke after successful percutaneous coronary revascularization were at greater risk for Q-wave infarction and death than nonsmokers. The cessation of smoking either before or after percutaneous revascularization was beneficial. Patients undergoing percutaneous revascularization should be encouraged to stop smoking.

Aged↗
PubMed1997

Mechanical pressure and stretch release endothelin-1 from human atherosclerotic coronary arteries in vivo.

BACKGROUND: Endothelin-1 (ET-1) is an endothelium-derived vasoactive peptide with mitogenic properties. In vitro, vascular release of ET-1 is increased in response to mechanical stress. The goal of the present study was to examine whether ET-1 is released from human atherosclerotic coronary arteries in vivo in response to mechanical pressure and stretch and to characterize immunoreactivity for ET-1 and its precursor, big ET-1, within the atheromatous plaque. METHODS AND RESULTS: Circulating ET-1 levels were measured in 20 patients before and after coronary angioplasty for stable angina at three sampling sites: the femoral artery and the coronary artery segments proximal and distal to the lesion dilated. In addition, atheromatous tissue obtained from 20 patients undergoing directional coronary atherectomy for stable angina were analyzed for immunoreactivity for ET-1 and big ET-1. In patients undergoing angioplasty, ET-1 levels in the distal coronary artery increased after balloon dilatation (8.4 +/- 0.9 to 16.4 +/- 2 pg/mL, P < .05); proximal coronary artery and systemic ET-1 levels were unchanged. The degree of mechanical stress applied (product of duration and pressure of balloon inflation) correlated with the change in distal coronary artery ET-1 levels (r = .71, P < .01). Immunoreactivity for big ET-1 and ET-1 was ubiquitous in the extracellular space and the intracellular compartment (macrophages, myointimal cells, myofibroblasts, and endothelial cells) of human coronary atheromatous tissue. CONCLUSIONS: Big ET-1 and ET-1 immunoreactivity is ubiquitous within the intracellular and extracellular compartments of coronary atherosclerotic tissue. ET-1 is released from these sites in response to mechanical stress. These findings support a role for endothelins in the evolution and progression of coronary atherosclerosis in humans.

Aged↗
PubMed1997

Maximal precordial ST-segment depression in leads V4-V6 in patients with inferior wall acute myocardial infarction indicates coronary artery disease involving the left anterior descending coronary artery system.

BACKGROUND: In inferior wall acute myocardial infarction, maximal ST-segment depression in left precordial leads (V4-V6) has been shown to be associated with increased in-hospital mortality, presumably due to coronary artery disease involving the left anterior descending coronary artery system. METHODS: We measured ST-segment deviation from baseline in the initial electrocardiogram of patients with inferior wall acute myocardial infarction, who subsequently underwent coronary angiography during their in-hospital stay. Patients were divided into three groups: (I) No precordial ST-segment depression (n = 34). (II) Maximal precordial ST-segment depression in leads V1-V3 (n = 44). (III) Maximal precordial ST-segment depression in leads V4-V6 (n = 14). RESULTS: The left anterior descending coronary artery or its diagonal branch were stenosed (> 50%) in 32%, 41%, and 71% of patients in groups I, II, and III, respectively (p = 0.04), and severely stenosed (> 70%) in 18%, 18% and 57% of patients in the respective groups (p = 0.007). CONCLUSION: In patients with inferior wall acute myocardial infarction, maximal precordial ST-segment depression in leads V4-V6 is suggestive of severe coronary artery disease involving the left anterior descending coronary artery or its diagonal branch.

Adult↗
PubMed1997

Clinical outcome of patients undergoing endoluminal coronary artery reconstruction with three or more stents.

OBJECTIVES: We sought to evaluate the outcome of patients undergoing multiple (three or more), contiguous stent implantation within a single native coronary artery. BACKGROUND: The implantation of multiple stents within a single coronary artery is increasing in frequency, although the outcome of such patients is not well described. METHODS: Forty-five patients without previous coronary artery bypass graft surgery (CABG) undergoing multiple, contiguous stent implantation in a single coronary artery were identified. Clinical and angiographic characteristics and outcomes were analyzed. RESULTS: The angiographic success rate was 97.8%. The procedural success rate was 91.1%; stent occlusion during the initial hospital period occurred in four patients (8.9%). Death, myocardial infarction (MI), CABG, repeat target vessel intervention or severe angina occurred in 10 (23.3%) of 43 hospital survivors at 6-months follow-up. The indication for stent placement was threatened or abrupt closure in 30 patients (66.7%). Of the 25 patients with abrupt or threatened closure whose clinical and angiographic data would have indicated emergent CABG had stents not been available, the frequency of in-hospital death and Q wave MI was similar to that of a matched consecutive series of patients at our institution who underwent emergent CABG after failed angioplasty. At 1 year, the frequency of death, Q wave MI, CABG and severe angina at 1 year was similar in the two groups; the need for repeat percutaneous intervention was more common in the stent group (25% vs. 0%, p = 0.01). CONCLUSIONS: Implantation of multiple, contiguous intracoronary stents was associated with a high initial success rate, although the incidence of early stent closure was relatively high. Adverse events at 6 months of follow-up were more frequent than previously reported for elective single-stent implantation; however, adverse angiographic characteristics such as dissection and thrombus were frequent in this group. In addition, the strategy of multiple stent implantation in the setting of failed angioplasty is a reasonable alternative to emergent CABG, although the need for further percutaneous intervention must be anticipated.

Angioplasty, Balloon, Coronary↗
PubMed1997

The effect of basic fibroblast growth factor on coronary vascular tone in experimental hypercholesterolemia in vivo and in vitro.

OBJECTIVE: To determine whether bFGF causes coronary vasoconstriction in experimental hypercholesterolemia in association with endothelial dysfunction. METHODS: We infused 0.02 microgram/kg per min bFGF into the left anterior descending artery of anesthetized pigs (n = 5) before and after 10 weeks of a high-cholesterol diet. The coronary artery diameter (CAD) was measured by quantitative angiography and the coronary blood flow (CBF) was calculated using coronary-flow Doppler measurements. In additional in-vitro studies, epicardial arteries from normal and hypercholesterolemic pigs were exposed to cumulative concentrations of bradykinin (10(-11)-10(-6) mol/l) after precontraction with 10(-6) mol/l endothelin-1. Cumulative concentrations of bFGF (10(-13)-10(-8) mol/l) were added to other vessels with and without prior contraction with 10(-5) mol/l PGF2 alpha. Similar in-vitro studies were performed using rings from which the endothelium had been removed. RESULTS: In vivo, intracoronary administration of bFGF increased the CBF by 33 +/- 33% and the CAD by 12 +/- 5% at baseline, but reduced the CBF by 45 +/- 8% and the CAD by 14 +/- 6% after 10 weeks of a high-cholesterol diet. In vitro, the endothelium-dependent vasorelaxation in response to bradykinin was attenuated significantly in coronary arteries from hypercholesterolemic pigs (P < 0.05). Cumulative concentrations of bFGF exerted no effect on the coronary epicardial tone both in normal (with and without endothelium) and in hypercholesterolemic pigs. CONCLUSIONS: Acute administration of intracoronary bFGF caused coronary vasodilatation under steady-state conditions and vasoconstriction under diet-induced hypercholesterolemia. In vitro, bFGF did not affect the coronary epicardial tone. These findings suggest that the coronary vasoactive properties of bFGF may be exerted indirectly and are affected by the functional integrity of the endothelium.

Animals↗
PubMed1997

Enhanced endothelin-B-receptor-mediated vasoconstriction of small porcine coronary arteries in diet-induced hypercholesterolemia.

The coronary vasoconstrictor effects of endothelins, mediated by both endothelin ETA and ETB receptors, may be differentially altered in pathophysiological states associated with endothelial dysfunction and elevated endothelin levels. Experimental hypercholesterolemia is associated with coronary endothelial dysfunction and increased circulating endothelin concentrations. These studies were designed to test the hypothesis that experimental hypercholesterolemia is characterized by a differentially altered coronary contractile response to ETA- and ETB-receptor stimulation, in vitro. Pigs were fed either a normal or a high-cholesterol diet for 10 to 13 weeks. Changes in the intraluminal diameter of pressurized small coronary arteries (< 481 +/- 25 microns in diameter) to cumulative concentrations (10(-10) to 10(-6) mol/L) of endothelin-1 (ET-1), and sarafotoxin 6c (S6c), a specific ETB-receptor agonist, were measured using a video dimension analyzer. The maximal contraction attained with ET-1 was greater than with S6c in both normal (86 +/- 7% versus 47 +/- 7%, P = .001) and hypercholesterolemic (77 +/- 6% versus 37 +/- 7%, P < .001) pigs. At 10(-10) mol/L, vessels from hypercholesterolemic pigs manifested greater contraction to both ET-1 (23 +/- 6% versus 8 +/- 3%, P = .02) and S6c (17 +/- 5% versus 4 +/- 2%, P = .02). Incubation of arteries from hypercholesterolemic pigs with BQ-788 (ETB-receptor antagonist), but not FR-139317 (ETA-receptor antagonist), altered the contractile response to ET-1 at 10(-10) mol/L. Removal of the endothelium abolished the difference in response to S6c between normal and hypercholesterolemic pigs. These studies demonstrate that experimental hypercholesterolemia is characterized by enhanced coronary vasoconstriction to endothelins in vitro, the mechanism of which is mediated mainly through the ETB receptor. Thus, the ETB receptor has a role in regulation of coronary artery tone in both the steady-state and pathophysiological states.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1997

Enhanced angiogenesis and unfavorable remodeling in injured porcine coronary artery lesions: effects of local basic fibroblast growth factor delivery.

There is interest in the role of growth factors in the genesis of arterial remodeling. We studied local administration of basic fibroblast growth factor (bFGF) to coronary lesions to determine whether there is a difference in remodeling and whether neovascularization could be induced in such stenoses and distal myocardium. Pigs were randomized to balloon infusion of either saline or bFGF at each thermally injured arterial site. After the animals were killed, their internal elastic lamina, neointima, and lumen areas were measured. Capillaries were counted in the arteries and myocardium. There was a greater loss of lumen and internal elastic in the bFGF group. The neointima, media, and myocardium in the bFGF treated arteries had statistically more capillaries. This study showed that local intracoronary bFGF, at a dose that results in arterial luminal revascularization in injured segments, adversely affects arterial remodeling. Thus, the angiogenic response to exogenous bFGF may be offset by concomitant shrinkage of injured arterial segments.

Animals↗
PubMed1997

Prevention of Groin Vascular Complications Associated with Percutaneous Procedures.

Groin vascular complications are frequent problems associated with percutaneous interventions. The potential for these problems may increase as more potent antiplatelet and anticoagulant regimens are tested and become more widely used. Prevention of these complications involves consideration of several factors including 1) technical factors of arterial entry; 2) early sheath removal; 3) careful monitoring of the patient after sheath removal; and 4) measurement of activated clotting time and 5) consideration of weight adjustment of heparin in selected patients in whom adjunctive medications are given. If local bleeding occurs, prompt evaluation is required to assess the site of bleeding, the reason for bleeding, and magnitude of hemodynamic compromise. Often local vascular complications can be treated without need for other invasiveive procedures. Prevention of vascular complications is essential to optimize the outcome of interventional cardiology care.

Journal Article↗
PubMed1996

Prognostic significance of the initial electrocardiographic pattern in patients with inferior wall acute myocardial infarction.

The purpose of the study was to determine whether the initial electrocardiographic pattern is predictive of in-hospital mortality in inferior wall acute myocardial infarction. It is commonly perceived that patients with acute myocardial infarction presenting with greater ST elevation have a worse prognosis. The initial electrocardiogram of patients (n = 213) with inferior wall myocardial infarction was categorized based on the pattern of ST-segment elevation in inferior leads: (A) ST <1 mm with tall T waves, (B) ST > or = 1 mm with normal terminal QRS, and (C) ST > or = 1 mm with distortion of terminal QRS. ST deviation from baseline was calculated for all leads. Patients with maximal precordial ST depression in V4-V6 and pattern A had an in-hospital mortality rate of 68.8% compared with 16.9% for the entire study group. By univariate analysis, only pattern A was significantly predictive of in-hospital mortality [odds ratio = 2.91, 95% confidence interval (CI) 1.22-6.93], but by multivariate analysis adjusted for (1) age, (2) diabetes mellitus, (3) previous myocardial infarction, (4) thrombolytic therapy, (5) precordial ST-depression pattern, and (6) patterns of ST elevation, maximal ST depression in V4-V6 was significantly predictive (odds ratio = 4.93, 95% CI 1.79-13.56), whereas pattern A was not (odds ratio = 1.12, 95% CI 0.36-3.52). Contrary to popular perception, patients with inferior wall myocardial infarction presenting with minimal ST-segment elevation are at highest risk for in-hospital mortality, especially if accompanied by maximal precordial ST depression in V4-V6.

Adult↗
PubMed1996

Evaluation of patients with minimally obstructive coronary artery disease and angina.

Atherosclerotic coronary artery disease is a progressive process adversely affecting the integrity of the coronary vasculature. In past years, most studies have focused on the morphological changes leading to compromised coronary blood flow in atherosclerosis. However, in recent years it has become apparent that abnormal coronary vasomotor regulation may precede or accompany gross morphological changes in coronary atherosclerotic disease. In fact, the pathophysiology of angina pectoris in many patients with risk factors for atherosclerosis and minimally obstructive disease may involve abnormal coronary vasomotor tone regulation. The aim of the present article is to describe a clinical approach to patients with angina pectoris and minimally obstructive coronary artery disease based on current knowledge of coronary vasomotor regulation.

Acetylcholine↗
PubMed1996

Prominent atrial wave and diastasis deflection in the radionuclide diastolic volume curve during exercise--sensitive marker for coronary artery disease.

It is well-known that many patients with coronary artery disease have reduced left ventricular diastolic distensibility with normal systolic function. However, researchers have to data focused on the diastolic rapid filling phase of the radionuclide volume curve in ischemic patients, paying less attention to the ensuing left ventricular filling associated with passive filling ('diastasis') and atrial contraction ('A' wave). We analyzed the radionuclide volume curves of 27 consecutive patients suspected ischemic heart disease, who manifested normal systolic function at rest and during exercise, as assessed by multigated equilibrium technetium-99m radionuclide cineangiography. For all patients, the amplitude of the maximal 'A' deflection relative to the peak of the diastolic curve (presented as percentage units) was calculated manually from the radionuclide left ventricular volume curves obtained at rest and during exercise. Twenty patients (Group I) had transient perfusion defects on thallium scintigraphy (treadmill), and 7 (Group II) did not. Patients in Group I manifested prominent 'A'-deflections during exercise, with a rise of 120 +/- 43% (mean +/- S.D.) from rest to exercise, whereas the patients in Group 11 had only 34 +/- 11% (mean +/- S.D.) rise in 'A' wave amplitude during exercise (P = 0.0001). We conclude that the appearance of a prominent 'A' deflection in the radionuclide left ventricular volume curve during exercise might be a sensitive marker of myocardial ischemia.

Adult↗
PubMed1996

Coronary angioplasty and intracoronary thrombolysis are of limited efficacy in resolving early intracoronary stent thrombosis.

OBJECTIVES: This study sought to evaluate treatment of early intracoronary stent thrombosis. BACKGROUND: Although refinements in intracoronary stent implantation technique and pharmacologic treatment have reduced the frequency of early stent thrombosis, stent thrombosis remains a feared complication of this procedure. Optimal treatment for stent thrombosis is still undefined. METHODS: Twenty-nine patients (44 stents) with early (< or = 30 days) coronary stent thrombosis over a 5-year period at our institution were identified. Treatment and outcome of stent thrombosis were analyzed. RESULTS: Mean (+/- SD) time from implantation to stent thrombosis was 6.1 +/- 5 days. Twenty-three patients were treated with catheter-based therapies (angioplasty alone in 14, angioplasty and intracoronary urokinase in 7, intracoronary urokinase alone in 2). Flow was restored without residual thrombus in 11 (48%) of the catheter-treated patients (6 of 14 with angioplasty alone, 4 of 7 with angioplasty and urokinase, 1 with urokinase alone). Of the 23 patients, 2 died despite restoration of anterograde flow, and 9 were referred for emergent or urgent bypass surgery because of residual thrombus and refractory angina despite restoration of blood flow. Of the remaining six patients, five were treated medically and one with coronary bypass surgery; three died. Acute myocardial infarction evolved in 26 patients (90%), including 20 (87%) of the 23 catheter-treated patients. CONCLUSIONS: Stent thrombosis is associated with severe adverse outcomes. Although catheter-based therapies are effective in restoring patency in a majority of patients, patients are referred frequently for coronary bypass surgery because of residual thrombus and refractory angina. These findings suggest that alternative or adjunctive therapies for stent thrombosis are needed.

Angioplasty, Balloon, Coronary↗
PubMed1996

Acute myocardial infarction entailing ST-segment elevation in lead aVL: electrocardiographic differentiation among occlusion of the left anterior descending, first diagonal, and first obtuse marginal coronary arteries.

Acute myocardial infarction with ST elevation in lead aVL may represent involvement of the first diagonal or the first obtuse marginal branch. This study assesses the correlation among different electrocardiographic patterns of acute myocardial infarction with ST elevation in aVL and the site of the infarct-related artery occlusion. Patients who underwent coronary angiography within 14 days of infarction with an unequivocal culprit lesion were included. Fifty-seven patients were evaluated. The culprit lesion was in the left anterior descending coronary artery proximal to the first diagonal, first diagonal, and first obtuse marginal branches, in 38, 8, and 11 patients, respectively. ST elevation in aVL and V2 through V5 signifies left anterior descending artery occlusion proximal to the first diagonal branch (positive predictive value [PPV] and negative predictive value [NPV] of 95% and 94%, respectively). ST elevation in aVL and V2, not accompanied by ST elevation in V3 through V5, favors occlusion of the first diagonal branch (PPV, 89%; NPV, 100%). ST elevation in aVL accompanied by ST depression in V2 predicts obstruction of the first obtuse marginal branch (PPV, 100%; NPV, 98%).

Cineradiography↗
PubMed1996

Is the heart a source for elevated circulating endothelin levels during aorta-coronary artery bypass grafting surgery in human beings?

Reports have shown increased systemic levels of endothelins during coronary artery bypass grafting in human beings. It was not known whether increased endothelin levels during coronary artery bypass grafting reflect a general systemic response to the surgical procedure or increased myocardial production of endothelins in response to ischemia and reperfusion. We therefore measured endothelin levels in the right atrium and proximal aorta of 15 patients undergoing coronary artery bypass grafting for anginal syndrome immediately before aortic crossclamping and again after cessation of cardiopulmonary bypass. In five patients, we also measured coronary sinus levels of endothelins during cardiopulmonary bypass circulation. We found that endothelin levels were elevated throughout the surgical procedure. Right atrial endothelin levels were significantly elevated after cessation of cardiopulmonary bypass circulation with respect to values immediately before aortic crossclamping (11.1 +/- 3.1 vs 14.2 +/- 3.7 pg/ml, p = 0.008), whereas endothelin levels in the proximal aorta did not rise significantly (10.5 +/- 2.3 vs 11.6 +/- 2.4 pg/ml, p > 0.5). Coronary sinus endothelin levels tended to decline temporarily during cardiopulmonary bypass circulation (11.1 +/- 2.1 pg/ml before aortic crossclamping, 7.9 +/- 1.9 1 minute after release of aortic crossclamp, and 9.9 +/- 2.1 pg/ml after release of partial aortic crossclamping, p = 0.06). We conclude that the rise in right atrial endothelin levels during coronary artery bypass grafting reflects systemic production and secretion of endothelins, probably by vasculature or organs distal to the proximal aorta, and is not the result of increased myocardial production and secretion of endothelins.

Aged↗
PubMed1996

The role of endothelin in coronary atherosclerosis.

During the evolution of coronary atherosclerosis, growth factors, cytokines, and other molecules are involved in cell recruitment, migration, and proliferation. Endothelin is an endothelial-derived vasoconstrictor peptide that possesses mitogenic properties. In this review, current evidence is provided that suggests that endothelin fulfills proposed criteria to be considered an atherogenic peptide because of its mitogenic and proliferative properties, as well as its inter-actions with known atherogenic factors. In addition, a proposed role of endothelin in the evolution of atherosclerosis is outlined.

Angioplasty, Balloon, Coronary↗