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Biomedical subjects

David Hilton

Publications and source records attributed to David Hilton.

6 recordsLinked to original sources

Vascular communications of the hand in patients being considered for transradial coronary angiography: is the Allen's test accurate?

OBJECTIVES: The purpose of this study was to assess the accuracy of the Allen's test (AT) in predicting hand ischemia in patients undergoing transradial coronary angiography. BACKGROUND: Patients with poor vascular communications between the radial artery (RA) and ulnar artery (UA), as indicated by an abnormal AT, are usually excluded from transradial coronary angiography to avoid ischemic hand complications. METHODS: Over a four-month period, patients undergoing coronary angiography were screened for AT time. Circulation in the RA, UA, principal artery of the thumb (PAT), and thumb capillary lactate were measured before and after 30 min of RA occlusion. RESULTS: Fifty-five patients were studied (20 normal, 15 intermediate, 20 abnormal). Three patients with an abnormal AT were excluded, owing to absence of detectible flow in the distal UA. Patients with an abnormal AT were all men, had a larger RA (3.4 vs. 2.8 mm; p <0.001), and smaller UA (1.9 vs. 2.5 mm; p <0.001), compared with patients with a normal AT. After 30 min of RA occlusion in patients with abnormal AT, blood flow to the PAT improved (3.2 to 7.7 cm/s; p <0.001) yet remained reduced relative to patients with normal AT (7.7 vs. 21.4 cm/s; p <0.001. Thumb capillary lactate was elevated in patients with an abnormal AT (2.0 vs. 1.5 mmol/l; p = 0.019). CONCLUSIONS: After 30 min of RA occlusion, patients with an abnormal AT showed significantly reduced blood flow to the thumb and increased thumb capillary lactate (compared with patients with a normal AT) suggestive of ischemia. Transradial cardiac catheterization should not be performed in patients with an abnormal AT.

Aged↗

Prevention of distal embolization and no-reflow in patients with acute myocardial infarction and total occlusion in the infarct-related vessel: a subgroup analysis of the cohort of acute revascularization in myocardial infarction with excimer laser-CARMEL multicenter study.

To overcome the adverse complications of percutaneous coronary interventions in thrombus laden lesions (i.e., distal embolization, platelet activation, no-reflow phenomenon), mechanical removal of the thrombus or distal embolization protection devices are frequently required. Pulsed-wave ultraviolet excimer laser light at 308 nm can vaporize thrombus, suppress platelet aggregation, and, unlike other thrombectomy devices, ablate the underlying plaque. The following multicenter registry was instituted to evaluate the safety and efficacy of laser ablation in patients presenting with acute myocardial infarction (AMI) complicated by persistent thrombotic occlusions. Patients with AMI and complete thrombotic occlusion of the infarct-related vessel were included in eight participating centers. Patients with further compromising conditions (i.e., cardiogenic shock, thrombolysis failures) were also included. Primary endpoint was procedural respective laser success; secondary combined endpoints were TIMI flow and % stenosis by quantitative coronary analysis and visual assessment at 1-month follow-up. Eighty-four percent of all patients enrolled (n = 56) had a very large thrombus burden (TIMI thrombus scale > or = 3), and 49% were compromised by complex clinical presentation, i.e., cardiogenic shock (21%), degenerated saphenous vein grafts (26%), or thrombolysis failures (5%). Laser success was achieved in 89%, angiographic success in 93%, and the overall procedural success rate was 86%. The angiographic prelaser total occlusion was reduced angiographically to 58% +/- 25% after laser treatment and to 4% +/- 13% final residual stenosis after adjunctive balloon angioplasty and/or stent placement. TIMI flow increased significantly from grade 0 to 2.7 +/- 0.5 following laser ablation (P < 0.001) and 3.0 +/- 0.2 upon completion of the angioplasty procedure (P > 0.001 vs. baseline). Distal embolizations occurred in 4%, no-reflow was observed in 2%, and perforations in 0.6% of cases. Laser-associated major dissections occurred in 4% of cases, and total MACE was 13%. The safety and efficacy of excimer laser for thrombus dissolution in a cohort of high-risk patients presenting with AMI and total thrombotic occlusion in the infarct-related vessel are encouraging and should lead to further investigation.

Aged↗

A comparison of the radial and the femoral approach in vein graft PCI. A retrospective study.

BACKGROUND: Transradial PCI is a safe and effective method of percutaneous revascularization. However, there is limited data on the efficacy of the transradial approach for saphenous vein graft (SVG) PCI. METHODS: We studied 334 patients who underwent SVG PCI between January 2000 and December 2003, and compared the radial (132 patients) and the femoral (202 patients) approach. RESULTS: Mean EF (55.6+/-18.6% radial versus 58.1+/-16.8% femoral), lesion location (proximal, mid, distal: 22.6/50.6/26.7% versus 22.6/44.5/32.9% respectively) and lesion type (B1/B2/C: 3.4/4.1/92.5% versus 0.4/3.1/96.5%) were similar in both groups (P>0.05). Five patients had a failed radial attempt (3.8%) and were switched to the femoral approach. Mean fluoroscopy time (20.4+/-12.2 versus 18.4+/-10.2 min), procedural time (60.0+/-27.2 versus 61.6+/-24.9 min) and the use of contrast (223+/-91 versus 234+/-91 ml) IIB/IIIA inhibitors (27.2 versus 33.2%), and stenting (81.5 versus 81.3%) were similar in both groups, whereas 5 or 6 French sheaths were used more often in the radial group (83.4 versus 64.9%, P<0.01). Angiographic success (93.9 versus 92.9%), in hospital MACE (radial:5 MI (3.8%) versus femoral: 1 death (0.5%) and 7 MI (3.5%) and major vascular complications (0.7 versus 0.5%) were also similar. CONCLUSIONS: The radial approach in SVG PCI is as fast and successful as the femoral.

Aged↗

Excimer laser angioplasty in acute myocardial infarction (the CARMEL multicenter trial).

Patients with acute myocardial infarction (AMI) with thrombus-laden lesions constitute a revascularization challenge. Thrombus and atherosclerotic plaque absorb laser energy; thus, we studied the safety and efficacy of excimer laser in AMI. In a multicenter trial, 151 patients with AMI underwent excimer laser angioplasty. Baseline left ventricular ejection fraction was 44 +/- 13%, and 13% of patients were in cardiogenic shock. A saphenous vein graft was the target vessel in 21%. Quantitative coronary angiography and statistical analysis were performed by independent core laboratories. A 95% device success, 97% angiographic success, and 91% overall procedural success rate were recorded. Maximal laser gain was achieved in lesions with extensive thrombus burden (p <0.03 vs small burden). Thrombolysis In Myocardial Infarction (TIMI) trial flow increased significantly by laser: 1.2 +/- 1.1 to 2.8 +/- 0.5 (p <0.001), reaching a final 3.0 +/- 0.2 (p <0.001 vs baseline). Minimal luminal diameter increased by laser from 0.5 +/- 0.5 to 1.6 +/- 0.5 mm (mean +/- SD, p <0.001), followed by 2.7 +/- 0.6 mm after stenting (p <0.001 vs baseline and vs after laser). Laser decreased target stenosis from 83 +/- 17% to 52 +/- 15% (mean +/- SD, p <0.001 vs baseline), followed by 20 +/- 16% after stenting (p <0.001 vs baseline and vs after laser). Six patients (4%) died, each presented with cardiogenic shock. Complications included perforation (0.6%), dissection (5% major, 3% minor), acute closure (0.6%), distal embolization (2%), and bleeding (3%). In a multivariant regression model, absence of cardiogenic shock was a significant factor affecting procedural success. Thus, in the setting of AMI, gaining maximal thrombus dissolution in lesions with extensive thrombus burden, combined with a considerable increase in minimal luminal diameter and restoration of anterograde TIMI flow, support successful debulking by excimer laser. The presence of thrombus does not adversely affect procedural success; however, cardiogenic shock remains a predictor of major adverse events during hospitalization.

Angioplasty, Laser↗

Crisis and connection.

Psychiatric interventions for crisis care lie at the center of the conflict between involuntary commitment and recovery/wellness systems in mental health services. Though crisis can mean completely different things to people who have the experience, the general public has been convinced by the media that people with psychiatric disabilities are to be feared. More and more this has led to social control but is erroneously still called treatment. This does nothing to help the person and in fact further confuses people already trying to make meaning of their experience. This paper offers a fundamental change in understanding and working with people in psychiatric crises. Rather than objectifying and naming the crisis experience in relation to illness, people can begin to explore the subjective experience of the person in crisis while offering their own subjective reality to the relationship. Out of this shared dynamic in which a greater sense of trust is built, the crisis can be an opportunity to create new meaning, and offer people mutually respectful relationships in which extreme emotional distress no longer has to be pathologized. The authors, who have had personal experience with psychiatric crises, have provided this kind of successful crisis counseling and planning and have designed and implemented peer support alternatives to psychiatric hospitalizations that support this model.

Crisis Intervention↗