PubMed Health⌕ Search

Biomedical subjects

J R Margolis

Publications and source records attributed to J R Margolis.

At least 19 recordsLinked to original sources
PubMed1992

Excimer laser coronary angioplasty.

Recent experience with excimer laser coronary angioplasty (ELCA) has shown the safety and efficacy of the technique in the treatment of coronary stenosis, with results similar to percutaneous transluminal coronary angioplasty (PTCA). Several advantages of the excimer laser for intravascular use have been identified by the ELCA Registry, a group of 15 institutions nationally that have pooled data on their cooperative experience with ELCA. Advantages include the ability of the laser to ablate atheroma with microscopic precision without thermal injury and the ability of vessel surfaces to heal without scarring. The initial results of the multicenter investigation of ELCA in 958 patients indicate that ELCA may be indicated particularly for long, diffuse lesions. With the advent of larger diameter catheters, ELCA is a viable alternative to PTCA. Restenosis was seen as a significant problem, and it remained problematic at 6-month follow-up. In comparison with conventional balloon angioplasty, ELCA may eliminate that component of restenosis due to inadequate dilation or elastic recoil, but it does not appear to affect restenosis caused by smooth muscle proliferation. Catheter design and energy delivery continue to evolve and may affect future results of laser coronary angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1991

Diffuse embolization following percutaneous transluminal coronary angioplasty of occluded vein grafts: the blush phenomenon.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 146 saphenous vein grafts in 116 patients. In 29 patients, 31 grafts were totally occluded. Myocardial staining lasting over 5 minutes--"the blush phenomenon"--followed the opening of the occluded grafts in 9 of these patients. In 5 of these 9, enzyme release suggested infarction. A sixth patient died within a few hours of PTCA, with suspected infarction. Autopsy demonstrated diffuse and extensive distal coronary arterial embolization of grumous material, including cholesterol crystals, platelets, and fibrin. The blush phenomenon was not seen following PTCA in the remaining 20 patients with total occlusions, nor in any of the 87 patients with stenosed grafts. We have not observed the blush phenomenon following PTCA of more than 3300 coronary arteries. Of the 9 patients demonstrating the blush phenomenon, 6 had a recent history of myocardial infarction or unstable angina pectoris, compared with 4 of the remaining 20 patients with occluded grafts. We now approach occluded grafts with injection of intragraft thrombolytic agents or with atherectomy prior to PTCA. Future approaches may include atherectomy or laser angioplasty.

Adult↗
PubMed1991

Multi-Hospital Eastern Atlantic Restenosis Trial. II: A placebo-controlled trial of thromboxane blockade in the prevention of restenosis following coronary angioplasty.

Since platelet interactions appear to play an important role in the development of restenosis, attenuation of thromboxane-mediated reactions may improve the long-term outcome following coronary angioplasty. Phase II of the Multi-Hospital Eastern Atlantic Restenosis Trial (M-HEART) is a prospective, randomized, placebo-controlled study of thromboxane blockade in the prevention of restenosis following successful coronary angioplasty. Two forms of thromboxane blockade are evaluated: aspirin (a nonspecific inhibitor of thromboxane synthesis) and sulotroban (a specific thromboxane receptor antagonist). The design of this multicenter trial and the rationale for use of sulotroban in the prevention of restenosis are reviewed in this report.

Angioplasty, Balloon, Coronary↗
PubMed1991

Clinical and angiographic determinants of primary coronary angioplasty success. M-HEART Investigators.

Clinical and anatomic determinants of the initial success of percutaneous transluminal coronary angioplasty were prospectively evaluated in 826 patients enrolled in the Multi-Hospital Eastern Atlantic Restenosis Trial (M-HEART). The 639 men and 187 women ranged in age from 31 to 85 years. Successful angioplasty (residual stenosis less than 50% and no major complications) was achieved in 886 (88.6%) of 1,000 lesions. Success rates were uniform among the eight individual centers. Outcome was not influenced by gender, age or other clinical features, including severity and duration of angina, prior myocardial infarction, rest pain, transient ST segment elevation, history of smoking or diabetes. In contrast, procedural outcome was significantly associated with lesion-specific angiographic factors. Stenoses 60% to 74%, 75% to 89%, 90% to 99% and 100% were associated with success rates of 96%, 90%, 84% and 69%, respectively (p less than 0.001). Angioplasty was less successful in calcified than in noncalcified lesions (82% versus 90%, p less than 0.01), in thrombotic than in nonthrombotic lesions (82% versus 90%, p less than 0.05) and in lesions in the right coronary artery than in other vessels (84% versus 90%, p less than 0.01). Outcome was not related to other anatomic variables, including lesion location (proximal versus distal), vessel size, eccentricity, stenosis length or translesional gradient. By multivariate logistic regression, preangioplasty percent stenosis, right coronary artery location and lesion calcification were demonstrated to be significant independent predictors of angioplasty success. Alternative clinical and angiographic variables did not contribute to this regression model.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

Percutaneous excimer laser coronary angioplasty.

To determine the efficacy of percutaneous excimer laser coronary angioplasty as an adjunct or alternative to conventional balloon angioplasty, 55 patients were studied in a multicenter trial. These patients underwent the procedure using a modification of conventional balloon angioplasty technique. A first-generation, 1.6-mm diameter catheter constructed of 12 individual silica fibers concentrically arranged around a guidewire lumen was used. Catheter tip energy density varied from 35 to 50 mJ/mm2. The mean number of pulses delivered at 20 Hz was 1,272 +/- 1,345. Acute success was defined as a greater than or equal to 20% increase in stenotic diameter and a lumen of greater than or equal to 1 mm in diameter after laser treatment. Acute success was achieved in 46 of 55 (84%) patients. Adjunctive balloon angioplasty was performed on 41 patients (75%). The percent diameter stenosis as determined by quantitative angiography decreased from a baseline of 83 +/- 14 to 49 +/- 11% after laser treatment and to 38 +/- 12% in patients undergoing adjunctive balloon angioplasty. The mean minimal stenotic diameter increased from a baseline of 0.5 +/- 0.4 to 1.6 +/- 0.5 mm after laser treatment and to 2.1 +/- 0.5 mm after balloon angioplasty. There were no deaths and no vascular perforations. One patient (1.8%) required emergency coronary bypass surgery. These data suggest that excimer laser energy delivered percutaneously by specially constructed catheters can safely ablate atheroma and reduce coronary stenoses.

Angioplasty, Laser↗
PubMed1990

Patient-related variables and restenosis after percutaneous transluminal coronary angioplasty--a report from the M-HEART Group.

As part of a randomized prospective study designed to investigate the restenosis process after percutaneous transluminal coronary angioplasty (PTCA), the relation between patient-related variables and restenosis rate was examined. A total of 722 patients had successful PTCA. Angiographic follow-up was scheduled for 6 +/- 2 months after the procedure and achieved in 510 patients (71%), yielding 598 lesions for analysis. The overall restenosis rate was 40%. The rate was higher in patients undergoing early restudy for a clinical event than in those undergoing routinely scheduled follow-up restudy (71 vs 22%, p less than 0.0001). Age, sex, cigarette smoking history, diabetes mellitus and history of previous myocardial infarction were not associated with restenosis rate. Angina duration and severity before PTCA were also unrelated to restenosis rate. In summary, these variables, many of which have been previously implicated in restenosis, were not found to be predictors of restenosis. The decision to perform PTCA in individual patients should not be negatively influenced by the presence of these factors.

Adult↗
PubMed1990

The M-Heart percutaneous balloon mitral Valvuloplasty Registry: initial results and early follow-up. The M-Heart Group.

The initial results, complications and early follow-up of 74 patients undergoing percutaneous balloon mitral valvuloplasty in seven hospitals participating in a multicenter registry are reported. Seventy-four patients with a mean age of 53 years had 75 valvuloplasty procedures performed over a 2.5 year period. Eighty-nine percent of the attempted procedures were completed and resulted in an increase in mean mitral valve area from 1.0 +/- 0.04 to 2.0 +/- 0.1 cm2 (p less than 0.0001); the valve area increased greater than or equal to 50% of the baseline valve area in 73% of the patients. Major complications included procedure-related death (2.7%), cardiac tamponade (6.7%), systemic embolism (2.7%) and emergency surgery (6.7%). At a mean follow-up period of 14.6 months, the condition of the majority of patients had improved, and 89% of 55 patients treated only with valvuloplasty were in New York Heart Association functional class I or II. Thus, hemodynamic and clinical improvement can be obtained in the majority of patients with mitral stenosis treated with balloon valvuloplasty in multiple centers. However, suboptimal results and major complications occurred in a significant number of patients and may limit this procedure to use by experienced operators in hospitals with facilities for cardiac surgery.

Adolescent↗
PubMed1990

Excimer laser coronary angioplasty: American multicenter experience.

Second generation angioplasty devices remove rather than displace atherosclerotic plaque. For such devices to be useful they must be capable of addressing the major problems not solved by balloon catheters: difficult anatomy, abrupt reclosure, and restenosis. Laser angioplasty systems have proven difficult to adapt to treatment of coronary artery disease, because of heat generation, problems with perforation, and inflexibility of optical fibers. The AIS excimer laser coronary angioplasty system couples a 308 nm pulsed excimer laser to multifiber over-the-wire catheters of 1.3 mm, 1.6 mm, and 2.0 mm diameters. The laser's uniquely long pulse width (250 ns) allows delivery of higher energies through smaller fibers. Because the catheter system is front firing, risk of perforation is reduced. The Excimer Laser Coronary Angioplasty Registry involves six institutions investigating the AIS excimer system. This report deals with 255 lesions in the first 210 patients in the registry. The study cohort resembles a standard angioplasty population in terms of demographics, symptomatology, vessels dilated, and complications. Unlike a standard PTCA cohort, the ELCA patients had a higher prevalence of chronic total occlusions, calcified lesions, long lesions and diffuse disease. Both very distal lesions and those that had previously failed PTCA were successfully treated with ELCA. The laser was successful in 85% of cases, but adjunctive balloon angioplasty was required in the majority. There were no instances of perforation.

Adult↗
PubMed1989

Coronary artery spasm complicating PTCA: role of intracoronary nitroglycerin.

During PTCA intracoronary (ic) nitroglycerin is used in our institution only in cases of suspected coronary artery spasm. In order to estimate the incidence of true spasm, records from 1400 consecutive PTCA procedures were retrospectively reviewed for use of ic nitroglycerin. For each of the 376 procedures where ic nitroglycerin was used, angiograms were reviewed to determine whether spasm had been present or whether there was some other complicating problem which had mimicked spasm. In 191 procedures (51%), spasm had apparently occurred. In 178 procedures (47%), there was evidence for dissection rather than spasm. Seven procedures (2%) had evidence for neither spasm nor dissection. These included three cases of guiding catheter injury, two procedures where unsuspected distal disease was found after opening of total occlusions, and one case each of branch vessel occlusion and no re-flow phenomenon. Spasm was more common during right coronary PTCA. It frequently occurred in areas remote from the PTCA site. In every instance spasm was reversed following administration of one or more boluses of ic nitroglycerin. On the basis of these data, coronary artery spasm occurs in 14% of PTCA procedures.

Angioplasty, Balloon↗
PubMed1978

The role of the exercise test in the evaluation of patients for ischemic heart disease.

A cohort of 1472 patients who underwent both exercise stress testing and coronary angiography within six weeks was examined. The data indicated that a combination of exercise parameters is both diagnostically and prognostically important. Almost all patients (greater than 97%) who had positive exercise tests at Stage I or Stage II had significant coronary artery disease. More than half of these (greater than 60%) had three vessel disease and over 25% had significant narrowing (greater than 50%) of the left main coronary artery. Patients who achieved Stage IV or greater exercise durations with either negative or indeterminate ST-segment response had less than a 15% prevalence of three vessel disease and less than a 1% prevalence of left main coronary artery disease. A low risk subgroup (75% of all non-operated patients) was identified with a twelve month survival greater than 99%. A high risk subgroup (11% of all nonoperated patients) was identified with a twelve month survival of less than 85%. The exercise test is a noninvasive, reproducible method to assess the presence and extent of anatomic disease and the prognosis when significant disease has been defined. It should be used in conjunction with other noninvasive tests to determine optimal management in patients evaluated for ischemic heart disease.

Angiocardiography↗
PubMed1978

Relationships among ventricular arrhythmias, coronary artery disease, and angiographic and electrocardiographic indicators of myocardial fibrosis.

This study was performed to determine the relationships among angiographic, hemodynamic, clinical, and electrocardiographic data and premature ventricular contractions (PVCs). Arrhythmias were analyzed by 24 hour Holter monitor in 244 patients evaluated for chest pain by coronary angiography and left ventriculography. Using a categorical linear model, the presence of myocardial fibrosis as indicated by both abnormal left ventricular contraction (LVC) and abnormal initial QRS on electrocardiogram was found to be the only independent predictor of both frequent and complex ventricular arrhythmias (P less than .0001). All other descriptors, including the number of diseased vessels (greater than or equal to 75% obstruction), were dependent upon abnormal LVC in their association with PVCs. When the right anterior oblique view of the left ventriculogram was divided into nine segments to allow automated quantiative analysis of LVC, the prevalence of frequent PVCs was directly related to the number of abnormally contracting segments. Of patients with 0 abnormal segments, 11% had greater than or equal to 2 PVC/hr, in contrast to 44%, 73% and 100% of patients with 1-3, 4-6, and 7-9 abnormal wall segments, respectively (P less than 0.01). A similar quantitative relationship was found between premature ventricular contractions and abnormal initial forces indicating previous myocardial infarction on the electrocardiogram.

Adult↗
PubMed1976

Aortocoronary bypass surgery: Correlation of angiographic symptomatic and functional improvement at 1 year.

Angiographic changes in the coronary circulation were evaluated in 60 patients 1 year after aortocoronary bypass surgery, and their relation to the postoperative clinical status was examined. Of 124 grafts implanted, 26 were closed, 7 stenotic and 91 (74 percent) patent at 1 year. Progression of occlusive disease occurred in 21 of 57 (37 percent) nongrafted and 78 of 123 (63 percent) grafted vessels. On the basis of location and severity of progression, significant lesions bypassed and patency of grafts, postoperative coronary perfusion was considered optimal in 16 patients (Group I), better in 24 (Group III). Complete freedom from chest pain or lessening of pain (improvement by two New York Heart Association functional classes) occurred in 88 and 79 percent of patients in Group III. Positive preoperative treadmill stress tests became negative after surgery in five of six patients in Group I, five of eight in Grojp II and three of eight in Group III. This study demonstrates that when progression of disease, graft patency and extent of revasculariztion are considered in combination, the postoperative angiographic status of the coronary circulation correlates well with clinical improvement at 1 year. These findings support the hypothesis that improved blood supply to ischemic myocardium is a major factor contributing to relief of angina pectoris after saphenous vein bypass surgery.

Coronary Artery Bypass↗
PubMed1976

The hemodynamic simulation of mitral regurgitation in ventricular septal defect after myocardial infarction.

The development of a ventricular septal defect (VSD) following myocardial infarction is an uncommon complication which clinically can be confused with mitral insufficiency due to infarction of a papillary muscle. The clinical and hemodynamic records of six patients with documented acute VSD secondary to myocardial infarction were analyzed to determine which descriptors would be of value in clinically separating these two entities. All six of our patients had a right heart catheterization showing an oxygen step-up consistent with a VSD, and five had a large pulmonary wedge V wave suggesting concomitant mitral insufficiency. The echocardiogram showed only nonspecific chamber enlargement. Since these patients were being considered for open heart surgery to close the VSD, left and right cardiac catheterization including selective coronary arteriography was done. Despite large V waves being present in the pulmonary wedge and/or left atrial pressure tracing in five of the six patients, no mitral insufficiency was present on the left ventricular cineangiograms. It is concluded that a large pulmonary wedge and/or left atrial V wave does not necessarily indicate mitral insufficiency. Since both a VSD and mitral insufficiency are surgically correctable, patients who develop new holosystolic murmurs following myocardial infarction should have complete right and left heart catheterizations with LV angiography for accurate diagnosis if surgical correction of the lesion is contemplated.

Acute Disease↗
PubMed1976

Community surveillance for coronary heart disease: the Framingham Cardiovascular Disease survey. Comparisons with the Framingham Heart Study and previous short-term studies.

It appears likely that intervention trials on a community scale against one or more coronary heart disease risk factors will begin in the near future. Prerequisite to the evaluation of the effectiveness of these trials is the accurate determination of coronary heart disease incidence rates. The Framingham Cardiovascular Disease Survey was undertaken to test the hypothesis that a short-term surveillance study of a defined population can generate accurate incidence rates for at least some categories of cardiovascular disease and that these rates are comparable with those obtained by longitudinal survey of the same population. In conjunction with the 1970 U.S. census, a 1 year survey was made of all new coronary heart disease events occurring in the town of Framingham, Mass. Surveillance was performed by several methods that were intentionally overlapping. During the study period, 244 coronary heart disease events occurred. Despite the relatively small size of the population, many of the well established epidemiologic characteristics of this disease were evident. The rates obtained by the cardiovascular disease survey were comparable with those obtained by the Framingham Heart Study, for the harder end points of myocardial infarction and death from coronary heart disease, but much smaller for the softer end point of angina pectoris, especially in women. These data and those from similar studies indicate that periodic short-term surveillance studies of target populations of major intervention programs can provide an economic method of generating incidence data for the evaluation of the impact of such programs on myocardial infarction and death from coronary heart disease.

Age Factors↗