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Biomedical subjects

G S Roubin

Publications and source records attributed to G S Roubin.

At least 145 records · Page 8Linked to original sources

Presentation and late outcome of myocardial infarction in the absence of angiographically significant coronary artery disease.

To determine the natural history of myocardial infarction (MI) in the absence of angiographically significant (no lesion greater than or equal to 50% diameter stenosis) fixed coronary artery disease (CAD), clinical and angiographic data and late outcome were studied in 43 such patients. The mean age was 45 +/- 11 years; 32 patients (74%) were cigarette smokers. Mild fixed CAD, present in 38 patients (88%), was more frequent in the artery supplying the MI zone (p less than 0.01). Filling defects or serial angiographic resolution of obstruction in the artery supplying the MI zone were present in 14 patients (33%). At late follow-up, 14 major cardiac events occurred in 9 patients, including revascularization in 3, recurrent MI in 6 and cardiac death in 5. Of 35 patients undergoing catheterization within 1 year of the index MI, cumulative risk of a major cardiac event was 9 +/- 4, 12 +/- 5 and 20 +/- 7% at 3, 19 and 37 months, respectively. Myocardial infarction in the absence of significant fixed CAD tends to occur in young smokers with mild CAD in the artery serving the MI zone. Superimposed intracoronary thrombus can be frequently implicated. In these patients, subsequent major cardiac events may occur more frequently than previously reported.

Adolescent↗

In-hospital cardiac mortality after acute closure after coronary angioplasty: analysis of risk factors from 8,207 procedures.

Cardiac death consequent to acute vessel closure after coronary angioplasty occurred in 13 of 294 closures from 8,207 consecutive procedures performed at two centers since 1981 (0.16% cardiac mortality rate). To determine the predictors of cardiac death after acute coronary closure, 50 clinical, angiographic and procedural variables were analyzed by an observer unaware of the clinical outcome for each of the 13 patients who died and also 100 patients randomly chosen, in whom vessel closure after angioplasty did not result in death during hospitalization. Univariate analysis found female gender (p less than 0.0001), collateral channels from the vessel dilated (p less than 0.0001), use of balloon counterpulsation (p less than 0.0002), pre- and postprocedural hypotension (p = 0.0003 and p = 0.003, respectively), jeopardy score greater than or equal to 2.5 (p = 0.003), left ventricular hypertrophy (p = 0.013), hypertension (p = 0.02), diabetes (p = 0.02) and multivessel disease (p = 0.03) to be predictive of death. Multivariate analysis found collateral vessels, female gender and multivessel disease to be independent predictors of death. Thus, cardiac death after elective coronary angioplasty is very rare in experienced centers and occurs most often in women with a large amount of potentially ischemic myocardium. Hypotension often precedes the fatal closure event. Close attention to the amount of potentially ischemic myocardium and to the fluid volume status of these patients would seem to be especially warranted.

Adult↗

Repeat coronary angioplasty: correlates of a second restenosis.

To identify the correlates of a second restenosis after repeat percutaneous coronary angioplasty, the records of 384 patients with single vessel disease who underwent repeat angioplasty for restenosis complicating a first elective angioplasty were examined. A second restenosis occurred in 47 (31%) of 151 patients having angiographic follow-up. Univariate correlates of a second restenosis were an interval between the first and second angioplasty less than 5 months (41 versus 20% of patients had restenosis, p less than 0.01), male gender (35 versus 12%, p less than 0.05), lesions length greater than or equal to 15 mm before the second angioplasty (62 versus 28%, p less than 0.05), diameter stenosis greater than 90% before the second angioplasty (67 versus 29%, p less than 0.05), final gradient greater than 20 mm Hg after the second angioplasty (52 versus 28%, p less than 0.05) and an additional site requiring dilation at the time of the second angioplasty (50 versus 29%, p = 0.10). Multivariate predictors of a second restenosis were an interval of less than 5 months between the first and the second angioplasty (p = 0.001), male gender (p = 0.001), lesion length greater than or equal to 15 mm before the second angioplasty (p = 0.001) and the need to have an additional site dilated at the time of the second angioplasty (p = 0.002). Patients at increased risk of restenosis after the second angioplasty can be identified and may serve as a useful population for intervention studies.

Adult↗

Incomplete redistribution in delayed thallium-201 single photon emission computed tomographic (SPECT) images: an overestimation of myocardial scarring.

To determine if incomplete redistribution at 4 h in exercise tomographic thallium-201 studies is always due to a myocardial scar, 141 patients were evaluated before and after a total of 160 successful percutaneous transluminal coronary angioplasty procedures. Thallium studies were analyzed using polar "bull's-eye" maps. For both immediate and delayed images, abnormalities were quantified as a thallium score by calculating a standard deviation-weighted sum of pixels greater than 2.5 SD below gender-matched normal limits. One hundred forty-four of 160 studies indicated abnormalities before angioplasty. Of these 144, incomplete redistribution occurred in 111 (77%): 16 (14%) in patients with and 95 (86%) in patients without prior Q wave myocardial infarction. After angioplasty, improvement in delayed image score occurred in 8 (50%) of 16 patients with prior infarction and 72 (76%) of 95 patients without prior infarction (p less than 0.05). After angioplasty, delayed images were normal in 1 (6%) of 16 patients with prior infarction and 32 (34%) of the 95 without (p less than 0.05). Before angioplasty, delayed image scores were positively correlated with scores in the immediate postexercise images in patients with (r = 0.84) and those without (r = 0.69) prior infarction. To determine if additional delayed images could help differentiate scar from ischemia, an 8 to 24 h delayed image was obtained in each of 40 other patients with incomplete redistribution at 4 h. Of 28 patients without prior infarction, 15 had no redistribution, and 13 had further redistribution at 8 to 24 h.

Adult↗

Angiographic and clinical predictors of acute closure after native vessel coronary angioplasty.

To determine predictors of acute coronary closure after PTCA performed with steerable catheter systems, we compared 140 procedures complicated by acute closure and 311 representative successful attempts from 4,772 procedures performed between April 1982 and March 1986. Sixteen clinical, 35 angiographic, and seven procedural variables were analyzed. Multivariate analysis found seven independent preprocedural factors related to closure: stenosis length of 2 or more luminal diameters, female gender, stenosis at a bend point of 45 degrees or more, stenosis at a branch point, stenosis-associated thrombus (filling defect or staining), other stenoses in the same vessel, and multivessel disease. In addition, four procedural factors were found to be associated with closure by univariate analysis: post-PTCA percent stenosis (p less than .001), intimal tear or dissection (p less than .001), use of prolonged heparin infusion (p less than .001), and post-PTCA gradient of 20 mm Hg or more (p = .004). Multivariate analysis of both preprocedural and procedural variables found six factors independently related to closure: post-PTCA percent stenosis, dissection, prolonged post-PTCA use of heparin, branch point location, fixed bend point location, and other stenoses in the vessel dilated. The risk of coronary closure after PTCA has many determinants. While an estimation of risk can be made before performing PTCA, the most powerful predictors of closure can only be assessed during the procedure itself.

Acute Disease↗

Clinical outcome 5 years after attempted percutaneous transluminal coronary angioplasty in 427 patients.

This study was performed to define the 5 year clinical status of 427 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) in 1981. Their mean age was 54 +/- 10 years (+/- 1 SD). Sixty-one percent had unstable angina, 23% had prior myocardial infarction, 86% had one-vessel disease, and 92% had normal left ventricular function. Sixty-seven percent of patients had left anterior descending artery stenosis. Angiographic success was achieved in 84% of patients. Coronary bypass surgery was required in 9.6% of patients, in 5.9% as an emergency procedure. There were no in-hospital deaths. Follow-up at 5 years was 100% complete. There were 15 late deaths (96.3 +/- 1.0% survival), including seven of cardiac cause (98.1 +/- 0.7% cardiac survival). Myocardial infarction occurred in 24 patients (94% freedom from myocardial infarction), coronary bypass surgery was required in 63 (84% freedom from bypass surgery), and 365 patients (85%) were asymptomatic at follow-up. At 5 years, 83 patients (20%) had required an additional PTCA. Unstable angina pectoris and proximal left anterior descending coronary artery stenoses were present in 162 patients. The overall survival and cardiac survival in this subset was 94.4 +/- 1.8% and 98.1 +/- 1.1%, respectively. The excellent survival and low event rates over 5 years in this population support the concept that PTCA is safe and effective for patients with symptomatic angina pectoris, single-vessel disease, and normal left ventricular function.

Actuarial Analysis↗

Influence of balloon size on initial success, acute complications, and restenosis after percutaneous transluminal coronary angioplasty. A prospective randomized study.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) is strongly associated with incomplete initial dilatation. To determine if oversized PTCA balloons would reduce the restenosis rate without increasing the risk of arterial dissection and acute complications, we prospectively randomized 336 patients to receive either smaller or larger balloons. Thirty-four percent of patients had multivessel disease and 18% had multisite dilatation. One hundred sixty-nine patients were randomized to PTCA with a larger balloon and 167 to PTCA with a smaller balloon. Balloon:artery diameter ratios were 1.13 +/- 0.14 in the larger group and 0.93 +/- 0.12 in the smaller group (p less than 0.001). The trial was halted as clinically important differences in acute complications emerged. Emergency bypass graft surgery, usually for the treatment of arterial dissection, was required in 7.1% of patients in the larger balloon group and 3.6% of patients in the smaller balloon group (p = 0.15). Myocardial infarction (Q wave and non-Q wave) complicated 7.7% of procedures in which large balloons were assigned and 3.0% of procedures in which small balloons were assigned (p = 0.056). There were no deaths in either group. The incidence of bypass surgery was 1.7% when the balloon:artery ratio was less than 0.9, 3.1% when the ratio was 0.9-1.1, and 7.8% when it was greater than 1.1. Stepwise logistic regression analysis demonstrated that larger balloon assignment, multiple lesion dilatation, and multivessel coronary artery disease were independent predictors of emergency surgery. Angiographic restudy rates were 50% in the larger group and 60% in the smaller group (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Intra-arterial stenting in the atherosclerotic rabbit.

The major problem associated with percutaneous transluminal coronary angioplasty is recurrence of the stenotic lesion. Balloon catheter-mounted intracoronary stent devices may reduce restenosis by improving luminal morphology and flow characteristics. This study assessed the effects of a stainless steel wire, interdigitating coil stent on restenosis in the atherosclerotic rabbit model. Fifteen cholesterol-fed rabbits with preexisting iliac arterial lesions induced by balloon deendothelialization were instrumented in one iliac artery with a 2.0-mm diameter stent after balloon dilatation; the contralateral iliac lesion was treated by dilatation only to serve as a control. The animals were given heparin with aspirin (60 mg) and aspirin every 3rd day until death. Arteriography was repeated 4 weeks after stenting, just before death. Tissue sections from stented and control arterial segments were analyzed morphometrically. Stented arteries had a significantly larger luminal diameter at restudy, whether measured by arteriography (1.38 +/- 0.19 vs. 0.94 +/- 0.35 mm, p less than 0.01) or from tissue sections (1.26 +/- 0.18 vs. 0.81 +/- 0.30 mm, p = 0.0001). Wall thickness of the stented segment was slightly, but significantly, less than the control segment (436 +/- 143 vs. 532 +/- 221 microns, p less than 0.05). Scanning electron microscopy of five stented atherosclerotic rabbit aortas revealed regeneration of a nonthrombogenic, confluent, flow-directed endothelium by 4 weeks after placement. Intra-arterial stenting may be of benefit in the prevention of restenosis by the preservation of a larger functional lumen and by a decrease in the neointimal hyperplastic response to arterial injury.

Angiography↗

Antianginal effects of nitroglycerin during exercise-induced angina: hemodynamic and left ventricular function changes related to indexes of myocardial oxygen consumption.

In 14 patients during exercise, intravenous nitroglycerin improved anginal threshold and increased workload compared with control subjects. At similar workloads, the decreased left ventricular volumes suggested decreased myocardial oxygen consumption due to peripheral unloading. At maximal exercise with nitroglycerin (50 +/- 17 to 79 +/- 15 watts), rate-pressure product and end-diastolic volumes were higher with less ischemia, suggesting myocardial supply was improved by nitroglycerin.

Angina Pectoris↗

Usefulness of ejection fraction response to exercise one month after acute myocardial infarction in predicting coronary anatomy and prognosis.

The prognostic value of left ventricular (LV) ejection fraction (EF) measured during maximal exercise testing early after acute myocardial infarction (AMI) was assessed in 75 patients, aged 65 years or younger, a mean of 36 days after AMI. At follow-up for a mean 12 months (range 6 to 26), medical complications developed in 15 patients: cardiac death in 5, ventricular fibrillation in 1, reinfarction in 2, unstable angina in 5, and severe cardiac failure in 2. Seven other patients underwent coronary artery bypass grafting for severe angina. When LVEF less than 50% at rest was compared with LVEF of 50% or more, the 2-year life-table survival free of complications was 54 +/- 21% compared with 84 +/- 19% (p less than 0.05). When exercise LVEF less than 50% was compared with LVEF of 50% or more, the 2-year survival rate free of medical complication was 42 +/- 32% compared with 83 +/- 20% (p less than 0.05). LVEF change from rest to exercise was not related to prognosis. Patients with combined medical and surgical events tended to have lower rest and exercise LVEFs, but changes in LVEF during exercise were again unrelated to prognosis. Sixty-five patients underwent coronary arteriography. After inferior AMI the mean LVEF was lower in those with multivessel than in those with 1-vessel coronary artery disease at rest (47 +/- 13% vs 59 +/- 7%, p less than 0.005) and during exercise (47 +/- 13% vs 59 +/- 9%, p less than 0.005); however, the change in LVEF during exercise was not related to coronary anatomy anatomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

Effect of propranolol and verapamil on oxygen utilization, acidosis and fatigue during exercise in stable angina pectoris.

Oxygen utilization, arterial and venous blood gas levels, hemodynamic values and exercise tolerance were compared before and after administration of propranolol and verapamil in 10 patients with stable angina pectoris. During exercise, propranolol decreased cardiac output (CO) by 22%; O2 extraction was increased and O2 consumption (VO2) did not change. With verapamil treatment, CO modestly increased (7%), O2 extraction decreased and VO2 did not change. In contrast to O2 utilization, the drugs produced opposite changes in mixed venous and arterial blood gas levels. Propranolol decreased mixed venous pH, increased CO2 tension and decreased the pH of arterial blood. Verapamil increased venous pH and decreased CO2 tension; pH of arterial blood did not change. The drugs yielded similar levels of antianginal efficacy, but patients exercised longer during verapamil therapy and were less fatigued. The hemodynamic and metabolic differences suggest that muscle perfusion during exercise influences the onset of fatigue and may help determine the choice of therapy.

Adult↗

Influence of the methodology of percutaneous transluminal coronary angioplasty on restenosis.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) remains the principal factor preventing broader application of this form of myocardial revascularization. Several methodologic variables contribute to the quality of the angioplasty result and may directly or indirectly influence restenosis rates after the procedure. PTCA operators attempt to minimize thrombotic activity at the angioplasty site by delaying PTCA when thrombus is present, with heparin and antiplatelet agents and with thrombolytic agents if thrombus is identified during the procedure. Therapy directed at preventing coronary artery spasm with nitrates and calcium antagonists has no proven efficacy in preventing restenosis. Residual stenosis and pressure gradient have been shown to be predictors of restenosis. Retrospective studies have indicated that a balloon to artery diameter ratio greater than 1 favors long-term patency; however, preliminary results of a prospective randomized study suggested that acute complications were more frequent with larger balloons. The interplay of other balloon-related variables (maximal inflation pressure, number of inflations, duration of inflations, balloon material and length of balloon) and the potential influence on restenosis are discussed. Recommendations for patient management after PTCA are also offered. A number of prospective randomized trials using antiplatelet agents and modification of risk factors are underway to test ability of these strategies to influence restenosis.

Angioplasty, Balloon↗

Restenosis after percutaneous transluminal coronary angioplasty: the Emory University Hospital experience.

Restenosis after coronary angioplasty, a gradual encroachment of the dilated arterial lumen by overgrowth of neointimal cells, occurs in a minority (25% to 30%) of patients. Clinical and anatomic descriptors of those patients who develop restenosis have been identified and suggest a complex, multifactorial etiology. Optimal initial enlargement of the diameter probably reduces the chance of restenosis on geometric grounds alone. The independent predictive value of a low final translesional pressure gradient indicates that adequate blood flow may reduce platelet adhesion and thrombus formation. The importance of the latter factor remains uncertain. Individual proliferative responses to the intimal and medial injury caused by balloon dilatation appear to be modulated by both lesion-specific and patient factors. Lesion-specific factors appear most important and relate to vessel site, tortuosity and branching. These factors are also thought to influence native atherogenesis but the relation between restenosis and atherogenesis remains obscure. Patient risk factors for coronary artery disease also appear to influence restenosis. Procedural factors and risk factor modification may partially modify the restenosis response; however, prevention of restenosis will depend on finding agents that block either stimulation or proliferation of smooth muscle cells.

Angioplasty, Balloon↗

Coaxial laser energy delivery using a steerable catheter in canine coronary arteries.

Intracoronary delivery of argon laser energy was studied in eight anesthetized mongrel dogs. A No. 4.5 French single lumen catheter, with steerable guidewire and an optical fiber, was introduced through a Judkins-type femoral-coronary guiding catheter into three left anterior descending and eight left circumflex coronary arteries. A total of 65 laser energy exposures were made coaxially at 24 sites in the 11 arteries. At five sites, angiographically evident arterial perforation occurred with the first laser exposure, while at seven sites multiple laser exposures were made without angiographically evident perforation. All eight dogs remained hemodynamically stable, and were electively killed 5 +/- 1 hours following the procedure. Sections of myocardium from territories supplied by treated arteries demonstrated minimal or no pathology in 10 cases, while one territory had a small zone of early myocardial necrosis. This study suggests that standard coronary artery catheterization techniques can be used to introduce and position a steerable guidewire and an optical fiber in canine coronary arteries. Laser energy can repeatedly be delivered coaxially. Short-term deleterious effects may be reduced or eliminated, and exposure of blood elements to argon laser energy does not appear to create debris.

Animals↗

Multicenter study of percutaneous transluminal angioplasty for right coronary artery ostial stenosis.

Over a 5 year period at three centers, 53 patients underwent percutaneous transluminal angioplasty of a right coronary artery ostial stenosis. The procedure was successful in 42 patients (79%) and unsuccessful in 11, of whom 5 (9.4%) required emergency coronary artery bypass grafting because of abrupt closure. The right coronary ostial lesion had distinctive technical requirements to achieve success, including high pressure balloon inflation (10 +/- 4 atm) and the need for unconventional right coronary guide catheters. Technical factors that account for increased difficulty in these patients include: problems with guide catheter impaction and ostial trauma; inability to inflate the balloon with adequate guide catheter support; and need for increased intracoronary manipulation. The stenoses were quite discrete (4 +/- 5 mm) and calcified in the majority (40) of the 53 patients. Long-term follow-up (mean 12.5 months, range 4 to 60) of these patients demonstrated clinical recurrence of angina in 20 patients (48%) and angiographically proved restenosis in 16 (38%). Repeat coronary angioplasty was successful in three of six patients for relief of symptoms for over 6 months. In conclusion, angioplasty of the right coronary ostial lesion compared with nonostial dilation leads to a suboptimal early success rate; an apparent high risk of emergency bypass surgery; and a high restenosis rate. Careful assessment of the patient with this lesion and improved technology appear to be warranted.

Angiography↗