David Hilton

Novel use of a high-energy excimer laser catheter for calcified and complex coronary artery lesions

This study was designed to evaluate safety and effectiveness of the 0.9 mm excimer laser coronary catheter with increased laser parameters. We report a prospective trial of 100 calcified and/or balloon‐resistant lesions where a new 0.9 mm excimer laser catheter was used at standard or higher energy level to facilitate angioplasty. Standard in‐hospital clinical and angiographic parameters were collected and measured. Laser technical success was obtained in 87 lesions (92%), procedural success was reached in 88 lesions (93%), and clinical success in 82 lesions (86%). Increased laser parameters were used for 29 resistant lesions. This new 0.9 mm excimer laser coronary catheter using higher energy parameters seems to be safe and effective for management of calcified and nondilatable lesions. Catheter Cardiovasc Interv 2004;62:155–161.

Body Mass Index, Periprocedural Bleeding, and Outcome Following Percutaneous Coronary Intervention (from the British Columbia Cardiac Registry)

The incidence of obesity is increasing throughout the industrialized world and is a major public health concern. Some studies have shown a paradoxical protective effect of moderate obesity on outcome after percutaneous coronary intervention (PCI). The association between bleeding, body mass, and outcome is not well established and formed the basis for the present study, which examined major bleeding rates and mortality after PCI in British Columbia during a 6-year period. We identified 38,346 consecutive patients from the British Columbia Cardiac Registry who underwent PCI from 1999 to 2005. Data were cross-referenced to determine outcomes at 30 days and 1 year. Information about bleeding after PCI was obtained by cross-referencing the British Columbia Cardiac Registry with the Central Transfusion Registry. Baseline patient characteristics were compared among body mass index (BMI) categories. A clear bimodal (U-shaped) relation was seen between BMI and mortality. BMI was a potent independent predictor of mortality, particularly evident in the underweight (BMI <18.5 kg/m(2); odds ratio [OR] 1.98, 95% confidence interval [CI] 1.6 to 2.5, p <0.0001) and morbidly obese (> or =40 kg/m(2); OR 1.61, 95% CI 1.28 to 2.08, p <0.0001) groups. Periprocedural transfusion was also associated with adverse outcome (OR 2.86, 95% CI 2.52 to 3.25, p <0.0001). Transfusion adopted the same bimodal distribution across the entire cohort. Emergent PCI and femoral access were procedural factors associated with outcome. In conclusion, major bleeding conferred an adverse long-term prognosis after PCI. Identifying demographic and procedural factors that increase risk will facilitate more accurate risk scoring of patients undergoing PCI and allow targeted bleeding-avoidance strategies. Body mass and female gender identified subgroups at much higher risk of bleeding after PCI, an observation that merits further study.

Comparison of the Radial and the Femoral Approaches in Percutaneous Coronary Intervention for Acute Myocardial Infarction

In conclusion, in selected patients, the transradial approach performed by skilled operators is as safe and feasible as the transfemoral for PCI in the setting of AMI. The major clinical advantage of the radial approach is the absence of major vascular access complications.

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±10.2min), procedural time (60.0±27.2 versus 61.6±24.9 min) and the use of contrast (223±91 versus 234±91ml) 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.

A comparison of the radial and the femoral approaches in primary or rescue percutaneous coronary intervention for acute myocardial infarction in the elderly.

Background: Access site complications are reduced using radial percutaneous coronary intervention (PCI). There is concern that technical difficulties using this approach can delay achievement of reperfusion during primary or rescue PCI for acute myocardial infarction (AMI) especially in elderly patients. Methods and Results: We studied 155 patients (pts)⩾70 years who underwent primary or rescue PCI for AMI; radial (Group1; 87 pts) or femoral (Group2; 68 pts). Baseline characteristics, the amount of IIB/IIIA inhibitor, contrast and heparin used, and TIMI flow pre and post PCI were similar in both groups (P>0.05). Time from arrival in the catheterization laboratory to the first balloon inflation (Group 1: 44.0±21.5 versus Group 2 38.8±18.7 min) was also similar, but was significantly longer (61.2±11.1 min) compared to both groups in patients with a failed radial approach (7 pts, 8%). Angiographic success, and in‐hospital MACE were also similar in the two groups, but vascular access site complications were significantly higher in Group 2 (0 versus 2.9%, P<0.05). Conclusion: The use of the radial approach in elderly patients undergoing primary and rescue PCI, when successful, is safe and effective as the femoral approach, and leads to fewer vascular complications.

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, thombolysis 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 ≥ 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. Catheter Cardiovasc Interv 2005;64:67–74.

Radionuclide angiography and endomyocardial biopsy in the assessment of doxorubicin cardiotoxicity

Thirty-eight patients with a mean age of 53.2 years (19 to 75 years of age), who were receiving doxorubicin (D) for malignant disease, were studied in order to determine the relationship between functional and morphologic myocardial changes at different dose levels. Serial patient evaluations included physical examination, chest x-ray, electrocardiogram (ECG), endomyocardial biopsy (EMB), and rest-exercise gated nuclear angiography (GNA), at doses of D ranging from 144 to 954 mg/m2 (mean, 426 mg/m2). Physical examination, chest x-ray, and ECG proved to be insensitive predictors of D cardiotoxicity. Correlation of GNA and EMB in 31 patient evaluations, exclusive of known heart disease, did not reveal any false-positive angiograms, and all abnormal GNAs were associated with abnormal biopsies. Use of stress GNA uncovered six abnormal ventricles which could have been missed with a rest GNA alone. It has been suggested that: (1) GNA is a reliable monitor of D therapy; (2) an exercise study should be performed when the rest ejection fraction is normal, but is unnecessary when the rest EF is abnormal; (3) all patients with a resting ejection fraction of less than 45%, exclusive of other cardiac disease, should have D discontinued; and (4) endomyocardial biopsy is useful in assessing D cardiotoxicity in patients with other possible causes of an abnormal GNA.