Biomedical subjects

Rafael Beyar

Publications and source records attributed to Rafael Beyar.

65 records · Page 4Linked to original sources

PubMed2000

Intermediate coronary artery stenosis: evidence-based decisions in interventions to avoid the oculostenotic reflex.

The prevalence of intermediate coronary artery stenosis (defined as a diameter stenosis of 40% to 70%) is quite large in patients undergoing PTCA. The coronary angiogram is considered the 'gold standard' for the definition of coronary anatomy, in spite of various limitations associated with its use. In recent years, sensor tipped guidewire based methods of physiologic assessment of stenosis severity, like myocardial fractional flow reserve, and poststenotic coronary flow reserve had established their role in the decision making in catheterization laboratory. The decision making should combine morphologic and physiologic assessment as better evidence based approach in guiding therapy to avoid the 'oculostenotic reflex'.

Journal Article↗

PubMed2000

Editorial.

Explore the source record for details and available documents.

Journal Article↗

PubMed2000

Editorial.

Explore the source record for details and available documents.

Journal Article↗

PubMed2000

Editorial.

Explore the source record for details and available documents.

Journal Article↗

PubMed2000

Clinical and angiographic results with the beStent: the Registry for Optimal beStent Evaluation (ROSE) trial.

BACKGROUND: Although safety and efficacy of the beStent (Medtronic Inc., Santa Rosa, CA, USA) have been described, the long-term angiographic and clinical outcomes have yet to be investigated. The ROSE (Registry for Optimal beStent Evaluation) trial was designed to assess the procedural safety of single 15 mm beStent implantation, and the six-month angiographic and 12-month clinical outcomes of patients treated with this novel coronary stent. METHODS: Patients with angina and a single de novo lesion in a native coronary artery of >/=2.75 mm diameter were included in this multicenter, prospective, observational trial. Clinical follow-up was obtained at one, six and 12 months. Angiography was performed before and after the stent implantation and at six months. The primary end-point included major adverse cardiac events (death, myocardial infarction and target lesion revascularization), major bleeding complications, and thrombotic occlusions at one-month follow-up. Secondary end-points were major cardiac-event-free survival at six- and 12-month follow-up and angiographic restenosis at six months. A total of 120 patients (80% male, mean age 58.6 +/- 10.6 years) with stable (48%) or unstable (44%) angina pectoris were allocated. The target vessel reference diameter pre-procedure was 2.85 +/- 0.52 mm. RESULTS: Minimal lumen diameter pre/post and at follow-up was 0.97 +/- 0.28 mm, 2.53 +/- 0.40 mm and 1.86 +/- 0.63 mm, respectively. Restenosis rate according to the >50% diameter stenosis criterion at six-month follow-up was 21.5%. At 12 months, the event-free survival rate was 75% (no deaths, two Q-wave and seven non-Q-wave infarctions, five bypass surgery interventions and 16 target lesion revascularizations), whilst 87% of the patients were free of angina pectoris. CONCLUSION: Despite the relatively high percentage of small vessels, the outcome of the ROSE trial is comparable to those observed in previous stent trials, indicating that the coronary beStent is safe and effective as a primary device for the treatment of native coronary artery lesions in patients with (un)stable angina pectoris.

Journal Article↗

PubMed1999

Deferring angioplasty in intermediate coronary lesions based on coronary flow criteria is safe: comparison of a deferred group to an intervention group.

The decision for revascularization in patients with intermediate coronary lesions remains a challenging topic, particularly when objective data of reversible ischemia are lacking. In some of the patients, coronary revascularization is performed or deferred without definitive evidence on the clinical significance of the coronary stenosis. We investigated the usefulness of coronary flow reserve (CFR) measurements in 28 patients with intermediate coronary lesions. We compared 20 patients who underwent angioplasty based on Doppler-wire-derived CFR with 8 patients for whom angioplasty was deferred (diameter stenosis of 50.7 +/- 2.0% versus 46.5 +/- 3.1%, P < 0.0001 and CFR of 1.80 +/- 0.32 versus 2.65 +/- 0.11, P = 0.002, respectively). Angioplasty resulted in normalization of the CFR to 2.57 +/- 0.53 (P < 0.0001, versus the baseline value). During a follow-up period of 58.1 weeks (range 23-149 weeks), eight patients in the revascularization group were readmitted to the hospital, one of them with a myocardial infarction in the territory of the target vessel, compared with only one admission in the deferred group. Target-vessel revascularization was performed in three patients (a fourth patient declined it) in the former group, compared with only one in the latter. Symptomatic improvement or no change in clinical status was observed in the majority of patients in both groups (90% in the revascularization group and 87.5% in the deferred group). We conclude that in a selected group of patients with intermediate coronary lesions, measurement of CFR may be a useful tool in determining the need for revascularization based on its physiologic significance. Importantly, deferring PTCA in patients with intermediate lesions and normal CFR values seems to be safe.

Journal Article↗

PubMed1999

Clinical trends in stent treatment of simple and complex coronary disease.

This is a retrospective analysis of a consecutive group of patients from a single medical center who underwent stent implantation. It describes 316 patients who constituted 53% of the angioplasty procedures carried out in a single year. The authors describe the complications and their 1-year follow-up. We aimed to study the short and long-term results of stenting in our centre in relation to multiple clinical and angiographic variables. During 1996, 316 consecutive patients were treated with stent implantation for a total of 381 coronary lesions. The pharmacological protocol methods of stent implantation and patient characteristics were used. Clinical variables were: age 59.1 3 10.7 years, diabetes mellitus 25.3%, hypertension 33.0% and angina pectoris 88.7% (unstable in 44.1%). Previous coronary surgery had been undergone by 9.2%. Multivessel disease was present in 56% of the patients. The indications for stenting were: primary 58.5%, suboptimal results 33.0% and threatened or acute occlusion 8.5%. Angiographic success was 98.9% and clinical success 96.8%. The major in-hospital complications were acute myocardial infarction (2.2%), acute revascularization (0.3%) and major bleeding (0.6%). All occurred within 24 h of revascularization. Repeated angiography was performed in 115 cases (30.2%) at 160.3 3 109.4 days after stent procedure for unstable angina (38.7%), stable angina (26.1%) and other causes (35.2%). The restenosis rate in those catheterized was 38.1%, with an overall clinical restenosis rate of 11.3% during the follow-up period. Restenosis was more prevalent among diabetic patients (17.9 vs 9.15%, P 3 0.02) and patients with prior balloon angioplasty (18.6 vs 9.75%, P 3 0.046). Clinical follow-up was available in 90.8% of the patients for 291 3 112 days. The actuarial survival at the end of the follow-up period was 93.8%. Death/myocardial infarction was associated with unstable angina pectoris (P 3 0.006), hypertension (P 3 0.001), smoking (P 3 0.046) and threatened or acute occlusion (P < 0.001). In the first year of extensive stent use, stenting is associated with high technical and clinical success rates. Long-term results after stent implantation are associated with the occurrence of acute or threatened occlusion, and the in-hospital complications diabetes mellitus and hypertension.

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PubMed1998

Plasma endothelin levels as a function of coronary artery manipulation during balloon angioplasty and high-speed rotational atherectomy.

This study was conducted to test the hypothesis that endothelin levels may be related to the coronary artery manipulation during balloon angioplasty (BA) or rotational atherectomy (RA). Blood endothelin levels were measured in 35 patients who underwent BA and in 11 patients who underwent RA followed by adjunctive balloon angioplasty. Arterial and venous levels were measured before, immediately after, and 24 h after the procedure. The levels were then related to the number of balloon inflations, the total inflation time and the maximal pressure in the balloon during inflation. There were no significant differences between groups or time periods. However, 24 h after BA the endothelin plasma levels in venous blood were directly related to the number of balloon inflations (r 3 0.49; P 3 0.03), to the total inflation time (r 3 0.67; P 3 0.005) and to the maximal inflation pressure (r 3 0.71; P 3 0.001). No such correlation was found in venous blood immediately after BA, either in arterial blood or in the RA group. It can be concluded that plasma endothelin levels do not change significantly after balloon angioplasty; however, venous endothelin levels 24 h after BA are related to procedural parameters, reflecting endothelial damage, which may determine the post-angioplasty late results.

Journal Article↗

PubMedDate not supplied

Anomalous origin of right coronary artery: diagnosis and dynamic evaluation with multidetector computed tomography.

16 slice multidetector CT findings of an anomalous right coronary artery originating from the left sinus of Valsalva are presented. Multidetector CT depicted the malignant coronary anomaly in great anatomic detail as well as enabled dynamic evaluation through the cardiac cycle, documenting a substantial reduction in arterial diameter during peak systole. This case illustrates the full capabilities of multidetector cardiac CT in the evaluation of coronary artery pathology.

Coronary Vessel Anomalies↗

PubMedDate not supplied

Anomalous origin of a posterior descending artery from the right pulmonary artery: report of a rare case diagnosed by multidetector computed tomography angiography.

The case of a mildly symptomatic 43-year-old man with evidence of reversible inferior wall ischemia by radioisotope stress testing is described. Invasive catheterization showed abnormal connections between the coronary arteries and the pulmonary circulation. Multidetector computed tomography elucidated the previously undescribed finding of a posterior descending artery originating from the right pulmonary artery.

Adult↗

PubMedDate not supplied

Ipsilateral intracerebral hemorrhage following carotid stent-assisted angioplasty: a manifestation of hyperperfusion syndrome--a case report.

A case of hyperperfusion syndrome manifested as intracerebral hemorrhage following carotid stent-assisted angioplasty while using intravenous abciximab is described. Review of literature regarding hyperperfusion syndrome in patients undergoing carotid artery revascularization is presented. Possible mechanisms of hyperperfusion and the role of arterial hypertension, anticoagulation, and antiplatelet treatment in the genesis of hyperperfusion syndrome are discussed. Widening use of percutaneous carotid revascularization necessitates physicians' awareness of early recognition of this complication.

Abciximab↗