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Biomedical subjects

J K Kahn

Publications and source records attributed to J K Kahn.

At least 73 records · Page 4Linked to original sources
PubMed1990

Early postoperative balloon coronary angioplasty for failed coronary artery bypass grafting.

In a small number of patients, coronary artery bypass grafting (CABG) fails to relieve anginal symptoms. The usefulness of coronary angioplasty for the treatment of early (less than or equal to 90 days) recurrent ischemia after CABG was examined. Forty-five patients were treated from 2 to 90 days after CABG, including 8 patients studied emergently for prolonged ischemic symptoms. One-, 2- and 3-vessel native disease was found in 4, 10 and 31 patients, respectively. At the time of postoperative angiography, the major anatomic mechanism of recurrent ischemia was complete vein graft occlusion in 12 patients (27%), internal mammary artery occlusion in 3 (7%), vein graft stenoses in 13 (29%), internal mammary artery stenoses in 10 (22%), unbypassed disease in 4 (8%) and disease distal to the graft insertion site in 3 (7%). Angioplasty was successful at 91 of 98 sites (93%), including 95% of 41 lesions in native arteries, 89% of 46 lesions in vein grafts and 100% of 11 internal mammary artery lesions attempted. Complete revascularization was achieved in 84% of patients. There were 2 in-hospital deaths and 2 myocardial infarctions. Two additional patients underwent repeat CABG before discharge after uncomplicated but unsuccessful angioplasty. At late follow-up of the 43 survivors (mean 44 months), there were 4 deaths, 2 of which were noncardiac. Repeat CABG was required in only 3 patients and repeat angioplasty was performed in 10. Angina was absent or minimal in 35 patients; 17 patients were employed full time. Thus, percutaneous transluminal coronary angioplasty can relieve myocardial ischemia after unsuccessful CABG in the majority of patients.

Adult↗
PubMed1990

Outcome following emergency coronary artery bypass grafting for failed elective balloon coronary angioplasty in patients with prior coronary bypass.

To assess frequency and outcome of emergency coronary artery bypass grafting (CABG) for failed coronary angioplasty in patients with prior CABG, 2,136 elective angioplasty procedures in prior CABG patients were reviewed over a 10-year period. Emergency surgical revascularization was required in 19 patients (0.9%) with prior CABG, compared with 130 of 6,974 patients (1.9%) without prior CABG (p = 0.001). The interval from the most recent CABG to the failed coronary angioplasty was 6.8 years (range 1 to 16). Referral for emergency CABG was made on the basis of an acute closure not responding to repeat dilatation in 12 native coronary arteries and in 7 saphenous vein grafts. Severe hemodynamic instability after acute closure required the placement of an intraaortic balloon pump in 3 patients, including 2 who required cardiopulmonary resuscitation. A total of 34 saphenous vein grafts and 1 internal mammary artery graft were placed emergently. Three patients with high-risk features (3 prior CABG operations in 1 patient, single remaining vessel to heart in 2 patients) could not be weaned from cardiopulmonary bypass. The remaining 16 patients were discharged after a mean hospital stay of 16 days. Four patients developed new Q waves after CABG. At follow-up (mean 52 months, range 3 to 99), 1 patient died late from an acute myocardial infarction. The 15 survivors had no or mild angina and were free of further CABG. Thus, emergency CABG after failed angioplasty in patients with prior CABG is required infrequently. In patients without extreme high-risk features, emergency repeat CABG can be accomplished with good hospital and long-term results.

Aged↗
PubMed1990

Usefulness of angioplasty during acute myocardial infarction in patients with prior coronary artery bypass grafting.

The efficacy and risk of reperfusion strategies for myocardial infarction in patients with prior coronary artery bypass surgery are uncertain. In this study 72 patients with prior bypass grafting underwent direct percutaneous transluminal coronary angioplasty without antecedent thrombolytic therapy. There were 26 anterior and 46 inferior infarctions, including 11 patients (15%) in cardiogenic shock. The baseline ejection fraction was less than 40% in 47 (65%) patients. Angioplasty was successful in 41 of 48 (85%) vein grafts and 24 of 24 (100%) arteries (difference not significant) at 5.1 +/- 4.0 hours from the onset of symptoms (79% treated less than 6 hours). There were no urgent bypass operations, strokes or transfusions. In-hospital survival was 90% (nonshock 95% vs shock 64%, p less than 0.01). Symptomatic acute reclosure occurred in 1 patient. Predischarge coronary arteriography in 34 patients demonstrated continued vessel patency in 32 infarct vessels (94%), although 5 of these vessels were redilated for restenoses. Predischarge paired ventriculography in 26 patients showed an increase in ejection fraction from 44 +/- 16% to 51 +/- 18% (p less than 0.01). One- and 3-year actuarial survival was 89 and 87%. Thus, prior coronary surgery should not preclude reperfusion therapy by direct angioplasty, which can be accomplished with low procedural risk, improvements in ventricular function and excellent in-hospital and late survival.

Aged↗
PubMed1990

Thrombus aspiration in acute myocardial infarction.

A 57 yr-old man suffered an in-hospital inferior myocardial infarction 9 yr following coronary artery bypass surgery. Emergency cardiac catheterization demonstrated a large, occlusive thrombus in the saphenous vein graft to the right coronary artery. Multiple balloon dilitations failed to lyse the thrombus. A guiding catheter was used to aspirate the thrombus from the graft and there was immediate pain relief.

Angioplasty, Balloon, Coronary↗
PubMed1990

Retrograde coronary angioplasty of isolated arterial segments through saphenous vein bypass grafts.

Progression of native coronary artery disease proximal to the placement of saphenous vein grafts may leave arterial segments isolated by stenoses on either side. In 16 patients, we attempted coronary angioplasty in a retrograde direction through saphenous vein grafts to revascularize 17 isolated arterial segments. The retrograde dilatation was successful in 12 of 17 attempts (71%). Failure in 5 attempts was due to severe angulation between the graft insertion site and the retrograde proximal arterial limb. There were no major complications of these procedures. Symptoms and signs of myocardial ischemia were relieved following successful retrograde dilatation. Thus, retrograde dilatation through saphenous vein grafts provides another means of achieving complete revascularization using coronary angioplasty in patients with prior coronary bypass surgery.

Angioplasty, Balloon, Coronary↗
PubMed1990

Balloon rupture due to lesion morphology during coronary angioplasty.

We report a case of coronary angioplasty of a left anterior descending artery lesion that was complicated by the rupture of three successive balloon catheters. Each rupture occurred as a pinhole jet of contrast into a diagonal side branch, causing subintimal staining. This case demonstrates that balloon rupture may result from lesion morphology.

Angioplasty, Balloon, Coronary↗
PubMed1990

Inflation pressure requirements during coronary angioplasty.

To examine the balloon inflation pressures required for successful percutaneous transluminal coronary angioplasty (PTCA), the maximal inflation pressure required for 477 coronary lesions in 200 consecutive patients was determined retrospectively. When graded balloon inflations just sufficient to achieve full expansion were used, the maximal inflation pressure used was less than or equal to 8 atm in 412 stenoses (86%) and was less than or equal to 10 atm in 463 stenoses (97%). Successful PTCA was achieved in 98% of lesions with a 3.5% major procedural complication rate. In a second group of 100 patients studied prospectively, the inflation pressure required to achieve full balloon expansion was less than or equal to 8 atm in 214 of 232 stenoses (92%) and less than or equal to 10 atm in 228 stenoses (98%). Thus, PTCA of coronary stenoses can be achieved with high success rates and low complication rates when graded inflations to pressures just sufficient to achieve full balloon expansion are performed. Most coronary stenoses will respond to pressures less than or equal to 8-10 atm.

Adult↗
PubMed1990

High-dose contrast agent administration during complex coronary angioplasty.

To examine the necessity and consequences of high-dose contrast media administration during coronary angioplasty, the records of 730 consecutive patients over a 6-month period were reviewed. The 54 patients (7%) requiring contrast agent doses greater than or equal to 400 ml were examined in detail. The mean contrast dose in this group was 496 +/- 76 ml (range 400 to 785 ml). Their mean age was 63 +/- 11 years (range 36 to 83 years), 10 patients had diabetes mellitus (19%), and four patients had a baseline creatinine level greater than or equal to 1.5 mg/dl (7%). Following coronary angioplasty, the serum creatinine rose from 1.1 +/- 0.2 to 1.2 +/- 0.3 (p = 0.08). The creatinine rose greater than or equal to 0.5 mg/dl in six patients (11%) and greater than or equal to 1.0 mg/dl in one patient (2%). Five of these six patients had either diabetes mellitus, baseline renal insufficiency, or both. Oliguria was not observed. The most important procedural factors contributing to the high doses of contrast media were multilesion and multivessel angioplasty in 96% and 83% of patients, respectively, prior bypass surgery in 52%, and combined diagnostic cardiac catheterization and angioplasty in 13%. Thus renal dysfunction following high-dose contrast agent administration during complex coronary angioplasty is infrequently associated with nephrotoxicity. Whenever possible, contrast doses in patients with diabetes mellitus and renal insufficiency should be minimized.

Adult↗
PubMed1990

Supported "high risk" coronary angioplasty using intraaortic balloon pump counterpulsation.

Hemodynamic support may be desirable for selected patients with high risk characteristics undergoing elective coronary angioplasty. Twenty-eight high risk patients were studied with elective intraaortic balloon pump support over a recent 30 month period. Their mean age was 66 years; 10 patients were greater than or equal to 70 years old. Class III or IV angina was present in 23 patients (82%). The mean left ventricular ejection fraction was 24% (range 15% to 50%) and was less than 30% in 25 patients (89%). Three vessel disease was present in 26 patients (93%) and 7 patients had significant left main coronary artery disease. Ninety (96%) of 94 attempts to dilate stenoses were successful, including multivessel angioplasty in 21 patients (75%) and five left main coronary artery dilations. Decreases in systolic blood pressure to less than or equal to 70 mm Hg occurred in 11 patients (39%), but augmented diastolic pressure was greater than or equal to 90 mm Hg at all times. No deaths or myocardial infarctions occurred within 72 h of coronary angioplasty. Vascular complications requiring surgical repair occurred in three patients who had good operative results and no need for transfusions. Thus, intraaortic balloon pump support in patients with high risk features undergoing elective coronary angioplasty appears effective and relatively benign, although definite benefit cannot be proved without a randomized study. Newer techniques, such as in-laboratory cardiopulmonary bypass, must be compared with the results obtained with intraaortic balloon pump support alone.

Aged↗
PubMed1990

Results of primary angioplasty for acute myocardial infarction in patients with multivessel coronary artery disease.

The influence of multivessel coronary artery disease on the outcome of reperfusion therapy for myocardial infarction has not been fully characterized. Direct coronary angioplasty without antecedent thrombolytic therapy was performed during evolving myocardial infarction in 285 patients with multivessel coronary artery disease at 5.2 +/- 4.2 h after the onset of chest pain. Two vessel disease was present in 163 patients (57%) and three vessel disease in 122 (43%). An anterior infarct was present in 123 patients (43%), cardiogenic shock in 33 (12%) and age greater than or equal to 70 years in 59 (21%). Angioplasty of the infarct-related vessel was successful in 256 patients (90%), including 92% with two vessel and 88% with three vessel disease (p = NS). Emergency bypass surgery was needed in six patients (2%). In-hospital death occurred in 33 patients (12%), including 13 with two vessel and 20 with three vessel disease (p less than 0.05). The mortality rate was only 4% in the subgroup of 101 patients who met entry criteria for thrombolytic trials. The in-hospital mortality rate was 45% in patients in shock and 7% in patients not in shock (p less than 0.01). Logistic regression analysis identified shock and age greater than or equal to 70 years as independently associated with in-hospital death. In 135 patients who underwent predischarge left ventriculography, global ejection fraction increased from 50% to 57% (p less than 0.001) and regional wall motion in the infarct zone improved in 59% of patients. Follow-up data were available in 251 patients (99%) at a mean of 35 +/- 19 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

The spectrum of symptomatic coronary air embolism during balloon angioplasty: causes, consequences, and management.

PTCA is a widely used method of myocardial revascularization. Although complications of this procedure have been characterized, air emboli to the coronary vasculature have rarely been reported and their appropriate management is uncertain. We report six cases of symptomatic coronary air emboli occurring during PTCA. The possible mechanisms of the introduction of air during PTCA include incomplete aspiration of guiding catheters, balloon rupture, insinuation of air with balloon catheter introduction or withdrawal; structural failures of the equipment, and constant negative suction of selfventing catheters left outside the body. Symptomatic responses range from mild angina to full cardiac arrest and tend to resolve spontaneously in 5 to 10 minutes. Treatment is aimed at supporting the patient for this brief period, and consists of 100% inspired oxygen, analgesics, arrhythmic therapy if needed, and pressor and balloon pump support as required. Greater awareness of the causes, prevention, and therapy of coronary air emboli will lead to the safer practice of PTCA.

Aged↗
PubMed1990

Short- and long-term outcome of percutaneous transluminal coronary angioplasty in chronic dialysis patients.

Accelerated atherosclerosis occurs in chronic renal failure. The role of percutaneous transluminal coronary angioplasty (PTCA) in chronic renal failure patients requiring dialysis has not been characterized. We studied 17 chronic dialysis patients requiring PTCA over a 6-year period. Their mean age was 60 years, four were diabetic, eight had severe hypertension, and seven had unstable angina. Angiographic success was achieved in 47 of 49 (96%) stenoses attempted, including multivessel PTCA in 12 patients. There was one procedural death, two non-Q wave myocardial infarctions following PTCA, and one additional in-hospital noncardiac death. The 15 survivors were asymptomatic on discharge (mean stay 11 days), but recurrent angina developed within 6 months in 12 patients. Angiography in 11 of these 12 patients demonstrated restenosis of 26 of 32 (81%) dilated sites. Repeat PTCA in six patients was followed by return of angina in four patients with restenosis in 11 of 12 sites. Bypass surgery was ultimately performed in four patients with long-term angina relief. During follow-up (mean 20 months), seven patients died (five from chronic renal failure, two cardiac deaths). Thus although PTCA in chronic dialysis patients is technically feasible and provides relief of angina, aggressive restenosis limits the long-term benefit. Coronary bypass surgery may be the preferred therapy for this unique patient group.

Angina Pectoris↗
PubMed1990

Catheterization laboratory events and hospital outcome with direct angioplasty for acute myocardial infarction.

To assess the safety of direct infarct angioplasty without antecedent thrombolytic therapy, catheterization laboratory and hospital events were assessed in consecutively treated patients with infarctions involving the left anterior descending (n = 100 patients), right (n = 100), and circumflex (n = 50) coronary arteries. The groups of patients were similar for age (left anterior descending coronary artery, 59 years; right coronary artery, 58 years; circumflex coronary artery, 62 years), patients with multivessel disease (left anterior descending coronary artery, 55%; right coronary artery, 55%; circumflex coronary artery, 64%), and patients with initial grade 0/1 antegrade flow (left anterior descending coronary artery, 79%; right coronary artery, 84%; circumflex coronary artery, 90%). Cardiogenic shock was present in eight patients with infarction of the left anterior descending coronary artery, four with infarction of the right coronary artery, and four with infarction of the circumflex coronary artery. Major catheterization laboratory events (cardioversion, cardiopulmonary resuscitation, dopamine or intra-aortic balloon pump support for hypotension, and urgent surgery) occurred in 10 patients with infarction of the left anterior descending coronary artery, eight with infarction of the right coronary artery, and four with infarction of the circumflex coronary artery (16 of 16 shock and six of 234 nonshock patients, p less than 0.001). There was one in-laboratory death (shock patient with infarction of the left anterior descending coronary artery).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1989

Estimation of jeopardized left ventricular myocardium in symptomatic and silent ischemia as determined by iodine-123 phenylpentadecanoic acid rotational tomography.

Whether patients with silent myocardial ischemia have a lesser mass of ischemic myocardium than patients with symptomatic ischemia is controversial. Forty-five patients with angiographic coronary artery disease (greater than or equal to 70% luminal diameter narrowing) were studied. All patients had ischemic patterns of myocardial uptake and clearance of the long-chain fatty acid perfusion/metabolic imaging agent iodine-123 phenylpentadecanoic acid after maximal exercise. Single-photon emission computed tomography was performed and 25 myocardial segments were analyzed using circumferential activity profile curves. The 21 patients with silent treadmill ischemia exercised longer than the 24 patients with painful treadmill ischemia (430 +/- 137 vs 337 +/- 96 seconds, p less than 0.01) and to a higher heart rate (138 +/- 21 vs 125 +/- 18 beats/min, p less than 0.05). Patients with treadmill silent ischemia had the same number of abnormally perfused myocardial segments as patients with painful treadmill ischemia (8.6 +/- 4.5 vs 6.5 +/- 4.1 segments, difference not significant) and the same number of reversibly ischemic myocardial segments (4.0 +/- 1.4 vs 4.2 +/- 3.0 segments, difference not significant). The angiographic severity and extent of coronary artery disease were similar in the 2 groups. Thus, in this selected group of patients, those with silent treadmill ischemia appear to have at least as great an extent of ischemic myocardium as patients with painful exertional ischemia.

Angina Pectoris↗