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D S Baim

Publications and source records attributed to D S Baim.

At least 37 records · Page 2Linked to original sources
PubMed2000

Importance of lesion length on new device angioplasty of native coronary arteries. NACI Investigators. New Approaches to Coronary Interventions.

The influence of lesion length on early and late outcomes after new device angioplasty has not been well documented. We reviewed the clinical and angiographic outcomes of 2,980 patients (3,902 lesions) undergoing new device angioplasty of native vessels enrolled in the New Approaches to Coronary Interventions (NACI) Registry. Patients were divided into three groups according to the longest lesion length (< 10, 10-20, and > 20 mm) treated. Patients with the longest lesions had more multivessel disease (56.9% vs. 49.0%, P<0.05), right coronary artery disease (52.7% vs. 32.0%, P<0.001), and total occlusions (19.1% vs. 2.5%, P<0.001) than patients with shorter lesions. Longest lesions had the smallest minimal lumen diameter (P<0.001) at baseline and at the end of the procedure. Although in-hospital events were similar, there were differences in clinical outcomes at 1 year due mainly to more target lesion revascularization in the longest lesion group (P<0.01). Multivariate analysis showed that each 1-mm increase in lesion length was associated with an increase relative risk of 1.014 (95% CI, 1.004-1.025) for target lesion revascularization at 1 year. We conclude that despite similar early clinical events, patients undergoing new device angioplasty of longer lesions have more target lesion revascularization at 1 year.

Aged↗
PubMed1999

In vivo assessment of stent expansion and recoil in normal porcine coronary arteries: differential outcome by stent design.

BACKGROUND: Despite the routine use of high pressure, coronary stents generally fail to achieve a cross-sectional area (CSA) >60% to 80% of the nominal CSA of their dilating balloon. The extent to which incomplete balloon expansion and postdeflation stent recoil contribute to this failure has not been fully evaluated. METHODS AND RESULTS: Thirty-two stents (8 Gianturco-Roubin II, 8 Palmaz-Schatz, 8 MultiLink, and 8 NIR) were deployed in nondiseased coronary arteries of 8 Yorkshire pigs. All stents were then expanded according to 1 of 3 balloon strategies: appropriately sized compliant balloons, oversized compliant balloons, or oversized noncompliant balloons. Continuous ultrasound imaging was performed during stepwise balloon inflation and deflation, with an 0.018-in imaging core positioned within the guidewire lumen of the balloon. In these normal arteries, balloon underexpansion relative to the nominal size was not observed. After balloon deflation, however, all stents showed significant recoil from their maximum inflated CSA. Recoil was significantly greater for the coil Gianturco-Roubin II stent (30% CSA) than for the 3 slotted-tube stent designs (15% to 17% CSA). CONCLUSIONS: In normal, compliant coronary arteries, stent recoil is the predominant mechanism by which stents fail to achieve the nominal CSA of their dilating balloon. The magnitude of this in vivo stent recoil is significantly greater than reported from bench testing and varies with stent design (coil versus slotted tube). Postdilatation strategies that result in controlled stent overexpansion are needed to overcome this recoil phenomenon and result in a final stent CSA that approximates the reference artery CSA.

Angioplasty, Balloon, Coronary↗
PubMed1999

Comparative analysis of early and late angiographic outcomes using two quantitative algorithms in the Balloon versus Optimal Atherectomy Trial (BOAT).

Although substantial intersystem variability has been shown among several commercially available quantitative angiographic (QA) analysis algorithms, no previous study has compared the angiographic findings using 2 different QA systems performed at the same central angiographic laboratory. The purpose of this study was to compare the early and late QA results obtained with the CMS (MEDIS) and ARTREK (ImageComm) QA systems in the Balloon versus Optimal Atherectomy Trial. Directional atherectomy (n = 496) or balloon angioplasty (n = 490) was performed in 986 patients; late QA follow-up was available in 767 patients (77.7%). QA analysis was performed by 2 independent observers using the CMS and ARTREK systems. Correlation between the 2 QA systems for baseline measurements was good (Pearson's R = 0.78), although the CMS system resulted in larger baseline reference diameter (RD) (3.22 +/- 0.45 vs 3.07 +/- 0.40 mm; p <0.0001) and baseline minimal lumen diameters (MLD) (1.05 +/- 0.35 vs 0.92 +/- 0.32; mm p <0.0001) than the ARTREK system. The final and follow-up RD (+0.17 and +0.11 mm, respectively) were also larger using the CMS system. In contrast, the final and follow-up measurements of MLD and percent diameter stenosis were not significantly different using the 2 QA systems. The QA system did not affect the ability to detect a difference in restenosis rates (>50% follow-up diameter stenosis) between the 2 treatment groups (CMS, directional atherectomy [31.8%]; balloon angioplasty [40.5%]; p = 0.013 and ARTREK, directional atherectomy [33.9%], balloon angioplasty [41.3%]; p = 0.036). Only lesion irregularity contributed to the difference in baseline measurements of MLD and percent diameter stenosis. We conclude that important differences in measurements of RD, baseline MLD, and percent diameter stenosis were noted using the CMS and ARTREK systems. Both systems, however, were able to detect a treatment benefit associated with directional atherectomy in BOAT. The comparability of other angiographic systems will require similar evaluation in other studies.

Algorithms↗
PubMed1999

An embolization containment device.

A coaxial catheter system for containment of distal embolization is described. Utilizing a novel 0.014" hypotube with a distal elastomeric occlusion balloon, the PercuSurge GuardWire functions as a guidewire while trapping distal embolization resulting from more proximal intervention. The particulate debris is evacuated with a single operator exchange aspiration catheter (Export catheter) prior to deflation of the distal occlusion balloon. This animal study confirmed the feasibility of concept. The system was easily delivered through tortuous coronary anatomy. The GuardWire served as an adequate rail for delivery of dilatation balloons and a multitude of stents. There was no evidence of deep wall damage from low-pressure inflation and apposition of the distal occlusion balloon.

Animals↗
PubMed1999

Short- and long-term histopathologic evaluation of stenting using a self-expanding nitinol stent in pig carotid and iliac arteries.

Stenting is increasingly being used to treat carotid artery disease. However, complications including distal embolization, stent thrombosis, stent collapse from external compression, the need for high-pressure inflation with increased neointimal response, or balloon rupture during stent expansion and stent loss are all potential problems and of concern. To address each of these specific concerns, a new stent was designed, which is self-expandable, made of nitinol, with temperature-dependent superelastic properties, and with high vessel wall surface coverage. Since this device has a number of novel characteristics, we aimed to assess the short- and long-term histopathologic response in pig carotid and iliac arteries. Single stents were deployed in pig carotid and iliac arteries after overstretch balloon injury. Angiograms were performed pre- and poststenting and prior to sacrifice. Intravascular ultrasound was used before implantation to determine vessel size. Vessels were examined histologically at 1 month (n = 6) and 6 months (n = 6) for morphometric analysis, hemorrhage and thrombus, endothelialization, and inflammatory and fibrotic responses. There was a 100% angiographic success rate at implantation. In one case, it was determined histologically that a single stent was implanted in a dissection plane of a pig's left iliac artery and was occluded by organized thrombus, with the true lumen being patent. At 6-month follow-up, this was the only evidence of a single stent occlusion, with flow adjacent to the stent in the true lumen. In the other vessels, the stents showed good vessel wall-stent apposition and the lumens were patent with a concentric and thin neointima. Inflammatory cells were rare and there were no mural thrombi. Coverage of the vessel wall by endothelial-like cells was complete at 1 month. The novel nitinol EndoStent appears to have favorable biocompatibility with minimal thrombus deposition or inflammatory response, and its use is feasible for clinical application in carotid and iliac arteries.

Alloys↗
PubMed1999

Acute and nine-month clinical outcomes after "suboptimal" coronary stenting: results from the STent Anti-thrombotic Regimen Study (STARS) registry.

OBJECTIVES: This registry collected the 30-day and 9-month clinical outcomes of patients whose coronary stent implantation was suboptimal, and compared them with the cohort of patients with "optimal" stenting in the randomized portion of the STent Anti-thrombotic Regimen Study (STARS) trial. BACKGROUND: Although "optimal" stenting combined with an aspirin and ticlopidine regimen carries a low (0.5%) incidence of subacute stent thrombosis, only limited data are available for patients in whom stents are deployed suboptimally. METHODS: In the STARS, 312 (15.9%) of 1,965 patients enrolled were excluded from participation in the randomized trial based on a perceived "suboptimal" result of coronary stenting. Of these, 265 patients met prespecified criteria for suboptimal stenting, and were followed in a parallel registry, which was compared with the randomized STARS optimal stenting cohort. The primary end point was a 30-day composite of death, emergent target lesion revascularization, angiographic thrombosis of the target vessel without revascularization and nonfatal myocardial infarction (MI) unrelated to direct procedural complications. RESULTS: Registry patients had a similar frequency of the primary end point compared with the overall randomized cohort (3.0% vs. 2.2%), with this end point correlating to use of multiple stents, smaller final lumen diameter and absence of ticlopidine from the poststent regimen. Overall 30-day mortality (1.1% vs. 0.06%, p = 0.009) and periprocedural non-Q wave MI (8.7% vs. 4.2%, p = 0.003) were more frequent in registry patients, and appeared to be related to acute procedural complications. Clinical restenosis was significantly higher for registry patients (26.8% vs. 16.0%, p = 0.001), relating to greater prevalence of independent predictors such as smaller final lumen diameter and multiple stent use. CONCLUSIONS: In the STARS registry, the inability to perform optimal stenting correlated with smaller final lumen diameter and longer stent length. With ticlopidine-containing regimens, the acute clinical results of "suboptimal" stent deployment are clinically acceptable, although they are not quite as good as those of optimal stenting using similar drug therapy.

Acute Disease↗
PubMed1999

Rheolytic thrombectomy with the Possis AngioJet: technical considerations and initial clinical experience.

Percutaneous revascularization of thrombus-containing lesions has an increased incidence of adverse events such as abrupt vessel closure, periprocedural myocardial infarction and death. Various pharmacologic and mechanical approaches have demonstrated modest angiographic success with significant periprocedural complications. The AngioJet (Possis Medical, Inc., Minneapolis, Minnesota) is a dual lumen catheter that uses the principle of rheolytic thrombectomy to remove unorganized thrombus. A previously unreported scoring system based on clinical and angiographic data may help to select patients most likely to benefit from AngioJet treatment. When compared with urokinase in the randomized VeGAS 2 Trial, AngioJet therapy yields greater angiographic success with a lower incidence of 30-day major adverse events. Technical considerations and complications are reviewed in detail.

Catheterization↗
PubMed1998

A clinical trial comparing three antithrombotic-drug regimens after coronary-artery stenting. Stent Anticoagulation Restenosis Study Investigators.

BACKGROUND: Antithrombotic drugs are used after coronary-artery stenting to prevent stent thrombosis. We compared the efficacy and safety of three antithrombotic-drug regimens - aspirin alone, aspirin and warfarin, and aspirin and ticlopidine - after coronary stenting. METHODS: Of 1965 patients who underwent coronary stenting at 50 centers, 1653 (84.1 percent) met angiographic criteria for successful placement of the stent and were randomly assigned to one of three regimens: aspirin alone (557 patients), aspirin and warfarin (550 patients), or aspirin and ticlopidine (546 patients). All clinical events reflecting stent thrombosis were included in the prespecified primary end point: death, revascularization of the target lesion, angiographically evident thrombosis, or myocardial infarction within 30 days. RESULTS: The primary end point was observed in 38 patients: 20 (3.6 percent) assigned to receive aspirin alone, 15 (2.7 percent) assigned to receive aspirin and warfarin, and 3 (0.5 percent) assigned to receive aspirin and ticlopidine (P=0.001 for the comparison of all three groups). Hemorrhagic complications occurred in 10 patients (1.8 percent) who received aspirin alone, 34 (6.2 percent) who received aspirin and warfarin, and 30 (5.5 percent) who received aspirin and ticlopidine (P<0.001 for the comparison of all three groups); the incidence of vascular surgical complications was 0.4 percent (2 patients), 2.0 percent (11 patients), and 2.0 percent (11 patients), respectively (P=0.01). There were no significant differences in the incidence of neutropenia or thrombocytopenia (overall incidence, 0.3 percent) among the three treatment groups. CONCLUSIONS: As compared with aspirin alone and a combination of aspirin and warfarin, treatment with aspirin and ticlopidine resulted in a lower rate of stent thrombosis, although there were more hemorrhagic complications than with aspirin alone. After coronary stenting, aspirin and ticlopidine should be considered for the prevention of the serious complication of stent thrombosis.

Aged↗
PubMed1998

Mechanical debulking versus balloon angioplasty for the treatment of diffuse in-stent restenosis.

Previous studies have shown a high rate of repeat intervention after treating diffuse in-stent restenosis with percutaneous transluminal coronary angioplasty (PTCA) alone. It is not clear whether debulking with atherectomy is more effective in this condition. Between January 1994 and February 1997, we treated 60 consecutive patients with diffuse in-stent restenosis of a native coronary artery using conventional PTCA (n=30) or debulking (with rotational or directional atherectomy) plus adjunctive PTCA (n=30). Paired angiograms were analyzed by quantitative angiography, and clinical follow-up was obtained in all patients at 1 month, 6 months, and 1 year after revascularization. The mean lesion lengths were 13.5+/-8.3 and 18.4+/-13.2 mm in the debulking and PTCA groups, respectively (p=0.09). Acute procedural success was 100% in both cohorts, with no major complications in either group. Treatment with atherectomy plus adjunctive PTCA resulted in lower postprocedure stenoses (18+/-10 vs 26+/-13%, p=0.01) than treatment with balloon angioplasty alone. At 1-year follow-up, repeat target vessel revascularization was required in 28% of patients in the debulking group compared with 46% in the PTCA group (p=0.18). Independent predictors of the need for repeat target vessel revascularization were longer lesion lengths, diabetes mellitus, and smaller postprocedure lumen diameter. Thus, the strategy of atherectomy and adjunctive PTCA for diffuse in-stent restenosis is safe, improves acute angiographic results compared with PTCA alone, and may decrease the need for target vessel revascularization.

Angioplasty, Balloon, Coronary↗
PubMed1998

One-year follow-up of the Stent Restenosis (STRESS I) Study.

We present the completed 1-year follow-up results of the original Stent Restenosis Study (STRESS I), in which 407 patients with symptomatic ischemic heart disease and new lesions of the native coronary circulation were randomly assigned to treatment with either the Palmaz-Schatz coronary stent or conventional percutaneous transluminal coronary angioplasty (PTCA). The present study compares the safety of elective stenting to balloon angioplasty (PTCA) in terms of freedom from clinical events up to 1 year after treatment. Patients were enrolled and treated from January 1991 through February 1993, and follow-up data were collected and verified until July 1995. Ninety-seven percent of all patients had complete follow-up (deceased or alive with known clinical status) beyond 8 months, and 94% beyond 11 months. Anginal status between 9 to 15 months postprocedure was available for 78% of patients. At 1 year, 154 patients (75%) assigned to stent implantation and 141 (70%) to PTCA were free of all clinical events (death, myocardial infarction, or any revascularization procedure), and 162 stent patients (79%) and 149 PTCA patients (74%) were free from death, myocardial infarction, or target lesion revascularization. Symptom-driven target lesion revascularization occurred in 12% of the stent group versus 17% of the PTCA group. None of these differences in clinical events was statistically significant. Only 2 patients in the stent group and 7 in the PTCA group had a first event after 239 days, and freedom from angina at 1 year was reported in equal frequency in both groups (84%). There appear to be no late adverse effects of stent implantation. However, these results are limited by low statistical power, narrow patient selection, and the anticoagulation regimen used in the early experience with this device.

Angioplasty, Balloon, Coronary↗
PubMed1998

Balloon angioplasty versus new device intervention: clinical outcomes. A comparison of the NHLBI PTCA and NACI registries.

OBJECTIVES: We sought to compare outcomes of patients treated in the National Heart, Lung, and Blood Institute (NHLBI) Percutaneous Transluminal Coronary Angioplasty (PTCA) and New Approaches to Coronary Intervention (NACI) registries. BACKGROUND: Coronary angioplasty has numerous shortcomings. New devices for performing coronary interventions have been introduced in an effort to improve clinical outcomes. METHODS: Under the sponsorship of the NHLBI, a registry of consecutive patients treated with PTCA during 1985 to 1986 was established. In 1990, the NHLBI funded a second registry, the NACI. The two registries used the same data coordinating center to collect detailed baseline and follow-up information. RESULTS: Patients enrolled in the NACI registry were older, had undergone more previous bypass surgery procedures and had more stenoses located in bypass grafts than patients in the NHLBI PTCA registry. Procedural success was achieved in 72.1% and 82.6% of patients in the PTCA and NACI registries, respectively; however, in-hospital and 1-year mortality rates were 1.0% versus 1.8% and 3.1% versus 5.9% for the PTCA versus NACI registries, respectively. After risk adjustment, there was no difference in 1-year mortality. Rates of target lesion revascularization (TLR) were 21.5% for the PTCA registry and 24.2% for the NACI registry. NACI registry patients had a higher risk for TLR and the composite end point of death, myocardial infarction or revascularization (relative risk 1.28 and 1.23, respectively). However, the NACI registry patients who received stents tended to have a lower adjusted TLR rate. CONCLUSIONS: This comparative study found no overall superiority of these newer devices in terms of patient survival or freedom from TLR after adjustment for baseline risk profiles. Although technologic improvements (especially improved stenting) continue, these observations highlight the importance of careful assessment of clinical results in the broad population of patients in whom interventions are used.

Angioplasty, Balloon, Coronary↗
PubMed1998

Final results of the Balloon vs Optimal Atherectomy Trial (BOAT)

BACKGROUND: Previous directional coronary atherectomy (DCA) trials have shown no significant reduction in angiographic restenosis, more in-hospital complications, and higher 1-year mortality than conventional balloon angioplasty (percutaneous transluminal coronary angioplasty [PTCA]). DCA, however, has subsequently evolved toward a more "optimal" technique (larger devices, more extensive tissue removal, and routine postdilation to obtain diameter stenosis <20%). METHODS AND RESULTS: The Balloon vs Optimal Atherectomy Trial (BOAT) was conducted to evaluate whether optimal DCA provides short- and long-term benefits compared with balloon angioplasty. One thousand patients with single de novo, native vessel lesions were randomized to either DCA or PTCA at 37 participating centers. Lesion success was obtained in 99% versus 97% (P=.02) of patients to a final residual diameter stenosis of 15% versus 28% (P<.0001) for DCA and PTCA, respectively, the latter including stents in 9.3% of the patients. There was no increase in major complications (death, Q-wave myocardial infarction, or emergent coronary artery bypass graft surgery [2.8% versus 3.3%]), although creatine kinase-MB >3X normal was more common with DCA (16% versus 6%; P<.0001). Angiographic restudy (in 79.6% of eligible patients at 7.2+/-2.6 [median, 6.9] months) showed a significant reduction in the prespecified primary end point of angiographic restenosis by DCA (31.4% versus 39.8%; P=.016). Clinical follow-up to 1 year showed nonsignificant 13% to 17% reductions in the DCA arm of the study for mortality rate (0.6% versus 1.6%; P=.14), target-vessel revascularization (17.1% versus 19.7%; P=.33), target-site revascularization (15.3% versus 18.3%; P=.23), and target-vessel failure (death, Q-wave myocardial infarction, or target-vessel revascularization, 21.1% versus 24.8%; P=.17). CONCLUSIONS: Optimal DCA provides significantly higher short-term success, lower residual stenosis, and lower angiographic restenosis than conventional PTCA, despite failing to reach statistical significance for reducing late clinical events compared with PTCA with stent backup.

Aged↗
PubMed1998

'Optimal' directional coronary atherectomy: final results of the Optimal Atherectomy Restenosis Study (OARS).

BACKGROUND: Previous clinical trials of directional coronary atherectomy (DCA) have failed to show significant improvement in early or late outcomes compared with balloon angioplasty (PTCA). The present study tested the hypothesis that more aggressive "optimal" atherectomy could be performed safely to produce larger initial lumen diameters and a lower late restenosis rate. METHODS AND RESULTS: The present study was a prospective multicenter registry of consecutive patients undergoing optimal DCA of de novo or restenotic lesions in 3.0- to 4.5-mm native coronary arteries. Optimal DCA was defined as using a 7F atherectomy device and adjunctive PTCA if necessary to achieve a < 15% residual stenosis. Six-month angiographic and 1-year clinical follow-up was planned in all patients. A total of 199 patients with 213 lesions met eligibility criteria for enrollment. Short-term procedural success was achieved in 97.5%, with a major complication rate (death, emergency bypass surgery, or Q-wave myocardial infarction [MI]) of 2.5%. There were no early deaths. Non-Q-wave MI (CK-MB > 3 times normal) occurred in 14% of patients. Mean reference vessel diameter was 3.28 mm. Mean diameter stenosis was reduced from 63.5% to a final stenosis of 7%. Late 1-year clinical follow-up revealed one cardiac death and a target lesion revascularization rate of 17.8%. The angiographic restenosis rate at 6 months was 28.9%, with the major predictor of restenosis being a smaller postprocedure lumen diameter. CONCLUSIONS: Optimal DCA produced a low residual percent diameter stenosis and a lower restenosis rate than seen in previous trials without an increase in early or late major adverse events.

Aged↗