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Biomedical subjects

D S Baim

Publications and source records attributed to D S Baim.

At least 163 records · Page 9Linked to original sources
PubMed1991

Early ostial vein graft stenosis: management by atherectomy.

During the initial perioperative period (1 mo to 1 yr) after saphenous vein coronary grafting, early stenosis and occlusion occurs in 5-8% of grafts due to intimal hyperplasia. We report a patient who developed ostial stenosis within 4 mo of bypass surgery at the aortotomy site of two vein grafts. Balloon angioplasty of the elastic stenoses did not provide significant luminal enlargement, but successful treatment of the lesions was obtained using directional atherectomy. Histological examination demonstrated intimal hyperplasia. Directional atherectomy may be an excellent technique for treatment of elastic ostial vein graft stenoses in lieu of conventional balloon dilatation.

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PubMed1991

Selective versus routine predischarge coronary arteriography after therapy with recombinant tissue-type plasminogen activator, heparin and aspirin for acute myocardial infarction. TIMI II Investigators.

To ascertain whether predischarge arteriography is beneficial in patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator (rt-PA), heparin and aspirin, the outcome of 197 patients in the Thrombolysis in Myocardial Infarction (TIMI) IIA study assigned to conservative management and routine predischarge coronary arteriography (routine catheterization group) was compared with the outcome of 1,461 patients from the TIMI IIB study assigned to conservative management without routine coronary arteriography unless ischemia recurred spontaneously or on predischarge exercise testing (selective catheterization group). The two groups were similar with regard to important baseline variables. During the initial hospital stay, coronary arteriography was performed in 93.9% of the routine catheterization group and 34.7% of the selective catheterization group (p less than 0.001), but the frequency of coronary revascularization (angioplasty or coronary artery bypass surgery) was similar in the two groups (24.4% versus 20.7%, p = NS). Coronary arteriograms showed a predominance of zero or one vessel disease (stenosis greater than or equal to 60%) in both groups (routine catheterization group 73.1%, selective catheterization group 61.3%). During the 1st year after infarction, rehospitalization for cardiac reasons and the interim performance of coronary arteriography were more common in the selective catheterization group (37.9% versus 27.6%, p = 0.007 and 28.6% versus 11.6%, p less than 0.001, respectively); however, the interim rates of death, nonfatal reinfarction and performance of coronary revascularization procedures were similar. At the end of 1 year, coronary arteriography had been performed one or more times in 98.9% of the routine catheterization group and 59.4% of the selective catheterization group (p less than 0.001), whereas death and nonfatal reinfarction had occurred in 10.2% versus 7.0% (p = 0.10) and 8.6% versus 9.0% (p = 0.87), respectively. Because the selective coronary arteriography policy exposes about 40% fewer patients to the small but finite risks and inconvenience of the procedure without compromising the 1 year survival or reinfarction rates, it seems to be an appropriate management strategy.

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PubMed1991

Laser balloon angioplasty: clinical, angiographic and histologic results.

Laser balloon angioplasty combines conventional coronary angioplasty with laser energy to transiently heat vascular tissue. Laser balloon angioplasty, was performed in 21 patients (aged 56 +/- 13 years), including 10 patients treated urgently after acute failure of conventional angioplasty and 11 patients treated with elective laser balloon angioplasty. Immediately after conventional angioplasty, laser doses (1 to 10 doses of 205 to 380 J each) were delivered during inflation of the laser balloon to a pressure of 4 atm. Seven (70%) of 10 patients with acute failure of conventional angioplasty were successfully treated with laser balloon angioplasty, but 3 (30%) were unsuccessfully treated with the laser procedure and required emergency coronary artery bypass surgery. In all three failures, the 3 mm laser balloon angioplasty catheter was not the optimal size for the vessel. In the 11 patients treated with elective laser balloon angioplasty (reference diameter 2.94 +/- 0.22 mm), the minimal luminal diameter increased from 0.45 +/- 0.25 to 1.85 +/- 0.46 mm after conventional angioplasty and to 2.44 +/- 0.29 mm after laser balloon angioplasty (p less than 0.001). This corresponded to a decrease in diameter stenosis from 84 +/- 9% before to 35 +/- 16% after conventional angioplasty and to 15 +/- 10% after laser balloon angioplasty (p less than 0.001). There were no instances of myocardial infarction, emergency coronary artery bypass surgery or death and no acute complications related to delivery of laser energy in this group. Follow-up coronary angiography was performed 5.5 +/- 1.1 months after laser balloon angioplasty in 18 patients discharged from the hospital after a successful procedure. Ten patients (56%) had angiographic restenosis, defined as recurrent diameter stenosis greater than 50%. Six patients were subsequently treated by directional coronary atherectomy, which revealed intimal proliferation indistinguishable from that in patients with restenosis after conventional angioplasty. In conclusion, laser balloon angioplasty may be effective in sealing severe coronary dissections and reversing abrupt closure associated with failed conventional angioplasty. After uncomplicated conventional angioplasty, laser balloon angioplasty improves immediate luminal dimensions, but restenosis appears to be mediated by intimal hyperplasia, similar to that seen after conventional angioplasty.

Angiography↗
PubMed1991

Coronary interventions in ischemic heart disease.

Coronary angioplasty has continued to undergo important developments, both in terms of the maturation of conventional balloon angioplasty, and the favorable preliminary results of a variety of novel adjunctive techniques. To the extent that these new techniques can address the residual limitations of conventional angioplasty--and thereby improve its success, safety, and durability--angioplasty is likely to become the dominant form of myocardial revascularization in the 1990s. To ensure that this tool is applied correctly, however, careful randomized trials must be performed to establish which medical, surgical, or catheter-based treatment represents the best approach to a given clinical situation.

Angioplasty, Balloon, Coronary↗
PubMed1991

Clinical experience with the Palmaz-Schatz coronary stent. Initial results of a multicenter study.

Stenting of native coronary arteries with a balloon-expandable stent was attempted in 226 patients after elective angioplasty. Delivery of the device was successful in 213 (94%) of the patients. Of these, 39 received aspirin and dipyridamole only (group 1) and 174 received aspirin, dipyridamole, and warfarin for 1-3 months (group 2). There was no abrupt closure (less than or equal to 1 day) or perioperative death in either group. In-hospital or perioperative complications in group 1 compared with group 2 were as follows: subacute closure (1-14 days), seven (18%) patients versus one (0.6%) patient, respectively, p less than 0.0001; myocardial infarction, five (13%) patients versus one (0.6%) patient, respectively; condition requiring urgent bypass surgery, one (2.5%) patient versus no patients, respectively. Thus, the incidence of major complications such as death, myocardial infarction, or a condition requiring urgent bypass surgery was 15% in group 1 and 0.6% in group 2. Clinical follow-up revealed that 92% of the patients were asymptomatic at 3 months after stenting compared with 6% before stenting (p less than 0.0001). Of the 13 patients who were symptomatic, nine underwent cardiac catheterization and, ultimately, successful elective coronary angioplasty or bypass surgery. We conclude that a high delivery success rate can be expected with this device and that clinical thrombosis is less frequent in anticoagulated patients than in nonanticoagulated patients. Furthermore, in this selected patient population, coronary stenting results in a low incidence of in-hospital and perioperative complications. Clinical success, defined by absence of symptoms, appears to be sustained at 3 months.

Angioplasty, Balloon, Coronary↗
PubMed1990

Internal mammary angiography: a review of technical issues and newer methods.

Up to 90% of coronary bypass operations in some centers now include at least one IMA graft. In parallel with the increased use of IMA grafts, our catheterization laboratory records for 1986-7-8 demonstrate a progressive increase in IMA angiography, both absolutely (11, 28, 48 cases/yr) and as a percent of restudy procedures performed after prior bypass (14, 25, 43%). Unfortunately, these records also show that cannulation of the right and left IMAs may involve substantial technical hurdles, resulting in a mean time of 19 +/- 19 min from catheter insertion to selective IMA angiography. Based on this experience, we review a standard technique for IMA angiography using preformed catheters, and describe alternative methods (including use of PTCA guidewires with or without super-selective catheters, and non-selective angiography utilizing a specially designed balloon occlusion catheter).

Angioplasty, Balloon, Coronary↗
PubMed1990

The Thrombolysis in Myocardial Infarction (TIMI) Trial phase II: additional information and perspectives.

Given the many thrombolytic agents and the number of ways in which they can be combined with mechanical revascularization, the treatment of acute myocardial infarction has been the subject of active study and lively debate, which are likely to continue for some time. Several studies, including TIMI IIA (2,3,10,22), have suggested that immediate catheterization and angioplasty offer no clinical benefit and have a greater complication rate than a more delayed invasive strategy, but TIMI II (1) and SWIFT (16) trials have suggested that an even more conservative strategy of reserving catheterization and coronary angioplasty after thrombolytic therapy for patients with recurrent spontaneous or exercise-induced ischemia may be the most desirable approach for the majority of patients similar to those entered into these trials.

Angioplasty, Balloon, Coronary↗
PubMed1990

Clinical and angiographic results of balloon-expandable intracoronary stents in right coronary artery stenoses.

Balloon-expandable stents were placed successfully in 35 (95%) of 37 patients whose right coronary artery lesion was believed to have a poor short- or long-term prognosis with conventional balloon angioplasty because of prior restenosis or adverse lesion morphology. Quantitative angiography showed a reduction in stenosis diameter from 83 +/- 14% to 42 +/- 14% after conventional balloon dilation, with a further reduction to -3 +/- 12% after stent placement (p less than 0.001). There were no acute stent thromboses, but one patient (with two stents and unstented distal disease) developed subacute thrombosis on day 8 after self-discontinuation of warfarin and was treated with thrombolytic therapy and redilation. Follow-up angiography was performed at 4 to 6 months in 25 patients, demonstrating restenosis (83 +/- 13%) in 4 (57%) of 7 patients with multiple stents, but only 3 (17%) of 18 patients with a single stent (p less than 0.05). Six of the seven in-stent restenotic lesions were subtotal (80 +/- 12%) and were subjected to repeat conventional balloon angioplasty (postdilation stenosis 13 +/- 21%). The 18 patients without restenosis had a maximal in-stent diameter stenosis of 29 +/- 15%, corresponding to a maximal focal neointimal thickness of 0.68 +/- 0.26 mm within the stented segment. These preliminary results suggest that the Schatz-Palmaz stent may be a useful adjunctive device in the performance of coronary angioplasty.

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PubMed1990

Comparison of immediate invasive, delayed invasive, and conservative strategies after tissue-type plasminogen activator. Results of the Thrombolysis in Myocardial Infarction (TIMI) Phase II-A trial.

To assess the value and timing of percutaneous transluminal coronary angioplasty (PTCA) after thrombolytic therapy for acute myocardial infarction (AMI), 586 patients in the Thrombolysis in Myocardial Infarction Study Phase II-A were randomized among three treatment strategies, one using immediate coronary arteriography followed by PTCA if appropriate (immediate invasive strategy group, n = 195), a second that deferred angiography and PTCA for 18-48 hours (delayed invasive strategy group, n = 194), and a third, more conservative, approach in which PTCA was used only if ischemia occurred spontaneously or at the time of predischarge exercise testing (conservative strategy group, n = 197). Predischarge contrast left ventricular ejection fraction, the primary study end point, was similar among the patients in all three treatment groups and averaged 49.3%. The finding of a patent infarct-related artery at the time of predischarge arteriography was equally common among the patients in the three groups (mean, 83.7%); however, the mean residual infarct artery stenosis was greater in the patients in the conservative strategy group (67.2%) as compared with the patients in the immediate invasive (50.6%) and the delayed invasive strategy groups (47.8%) (p less than 0.001). Immediate invasive strategy led to a higher rate of coronary artery bypass graft surgery (CABG) after PTCA (7.7%) than did delayed invasive and conservative strategies (2.1% and 2.5%, respectively; p less than 0.01). Furthermore, among patients not undergoing CABG during the first 21 days, blood transfusion of more than 1 unit was used in 13.8% of the patients in the immediate invasive strategy group, 3.1% of the patients in the delayed invasive strategy group, and 2.0% of the patients in the conservative strategy group (p less than 0.001). At 1-year follow-up, the three treatment groups had similar cumulative rates of mortality (8.7%, pooled over all groups), fatal and nonfatal reinfarction (8.5%), combined death and reinfarction (14.5%), and CABG (17.2%), although the cumulative performance rate of PTCA remained higher in the invasive groups (immediate invasive strategy group, 75.8%; delayed invasive strategy group, 64.3%; and conservative strategy group, 23.9%; p less than 0.001). Thus, because conservative strategy achieves equally good short- and long-term outcome with less morbidity and a lower use of PTCA, it seems to be the preferred initial management strategy.

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PubMed1990

Coronary atherectomy. Clinical, angiographic, and histological findings and observations regarding potential mechanisms.

Between August 5, 1988 and August 1, 1989, we attempted percutaneous directional coronary atherectomy of 76 lesions, including 42 primary lesions and 34 restenosis lesions that developed after one or more prior interventions. The procedure was successful in 67 lesions (88%), with a decrease in diameter stenosis from 80 +/- 11% to 5 +/- 15% after atherectomy (p less than 0.01). One or more complications occurred in six patients (9%), including non-Q wave myocardial infarction (three patients, 4.5%), femoral arterial injury requiring surgical repair (two patients, 3%), and proximal dissection leading to emergency bypass surgery (one patient, 1.5%). Despite these favorable acute results, the 6-month lesion restenosis rate was 30% by life-table analysis. Light microscopy of retrieved tissue revealed atherosclerotic plaque in 94%, media in 67%, and adventitia in 27%. Intimal proliferation was present in 97% of the restenosis lesions but was also evident in 33% of primary lesions. Tissue weight from 27 lesions averaged 18.5 mg (range, 5.8-45.1 mg), which is not adequate to explain the entire angiographic improvement. Thus, part of the improvement in lumen diameter appears to be due to mechanical dilatation rather than to tissue removal alone. Atherectomy can predictably treat selected coronary lesions with overall safety comparable to that of conventional balloon angioplasty, although the procedure as currently performed does not derive all of its benefit from tissue removal and does not appear to prevent restenosis.

Angiography↗
PubMed1989

Randomised trial of fish oil for prevention of restenosis after coronary angioplasty.

To examine the potential role of fish oil supplementation in the prevention of restenosis after coronary angioplasty (PTCA), a randomised double-blind trial was conducted in 204 patients. The treatment group received 6 g/day of n-3 fatty acids, beginning 5.4 (SD 3.2) days before PTCA, and continuing for 6 months; the control group received olive oil placebo. Compliance was assessed by pill count and plasma levels of eicosapentaenoic acid (EPA). Restenosis was identified by symptoms and exercise testing and confirmed by angiography. PTCA was successful in 186 patients (93%). The incidence of angiographic restenosis was 34% in the fish oil group and 23% in the control group (relative risk 1.7, 95% CI 0.9-3.4). The lack of benefit of fish oil was not influenced by length of pretreatment, compliance with study medication, or the concentrations of plasma EPA achieved.

Angioplasty, Balloon↗
PubMed1989

Benefit of the perfusion catheter for emergency coronary artery grafting after failed percutaneous transluminal coronary angioplasty.

Of 2,102 consecutive patients who underwent percutaneous transluminal coronary angioplasty, 31 (1.5%) had emergency coronary bypass grafting for failed angioplasty. To determine the potential impact of different therapeutic strategies for controlling associated myocardial ischemia, 3 groups were analyzed. Group 1 comprised 11 patients (36%) in whom a "bailout" catheter was used to maintain anterograde coronary perfusion, group 2 included 16 patients (52%) in whom only intraaortic balloon counterpulsation was used and group 3 contained 4 patients (13%) in whom neither bailout catheter nor intraaortic balloon was used. Despite a longer average time to cardiopulmonary bypass, patients managed with the bailout catheter had a significantly lower incidence of Q-wave myocardial infarctions (9 vs 75%, p less than 0.05) compared with patients managed with intraaortic balloon counterpulsation alone. Those managed with the bailout catheter also had more consistent resolution of ST elevation and greater use of internal mammary artery grafts than patients supported by intraaortic balloon counterpulsation alone.

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