Excimer laser revascularisation: current indications, applications and techniques.

The ultraviolet pulsed excimer laser (308 nm wavelength) is currently the only laser approved by the FDA for percutaneous intervention in patients with ischemic coronary artery disease. The clinical presentation of the treated patients varies from stable and unstable angina to acute myocardial infarction. Potential advantages of excimer laser revascularisation in acute coronary syndromes and in ischaemic obstructive peripheral vascular disease include concomitant plaque debulking and thrombus removal; absence of systemic lytic state; shortened thrombus clearing time and facilitation of adjunct balloon angioplasty and stenting. Improved understanding of laser-tissue interactions and positive clinical outcomes through the use of safe lasing techniques have led to expansion of indications/applications for laser angioplasty. These include stent restenosis, complex lesions and thrombotic stenoses, bifurcation lesions, balloon failure, total occlusions, focal saphenous vein graft lesions and peripheral arterial obstructions. The excimer laser can be effectively utilised in patients with depressed left ventricular ejection fraction and does not require implantation of a temporary pacemaker as no-reflow phenomenon and severe arrhythmias are rarely encountered. Careful case selection, proper utilisation of equipment and incorporation of efficient lasing techniques play a crucial role in effective and safe cardiovascular laser applications.

Excimer laser for revascularisation of saphenous vein grafts.

Coronary artery bypass grafting has been a major advance in cardiovascular medicine over the past 30 years. Saphenous venous bypass grafts, however, are prone to develop atherosclerotic disease within several years of the procedure. Unfortunately, percutaneous interventional techniques in saphenous venous bypass grafts are associated with significant risks of distal embolisation and resultant non-Q wave myocardial infarction. Preliminary results suggest excimer laser angioplasty may significantly reduce this complication. This article summarises the results of percutaneous interventions in spahenous venous bypass grafts, emphasising the potential role of excimer laser angioplasty in this group of patients.

Assessing myocardial viability using the coronary flow response to intravenous dobutamine infusion in recent myocardial infarction.

Coronary flow response to low-dose (5 and 10 micrograms/kg/min) dobutamine infusion was used to assess myocardial viability at the time of cardiac catheterization in 13 patients (age, 60 +/- 11 years) with recent myocardial infarction. Echocardiographic improvement in regional wall motion performed 4 to 6 weeks after discharge was used as the marker for viability. Viable patients demonstrated a 2-fold increase in flow from baseline (p < 0.001) during intravenous infusion. In contrast, patients without viability demonstrated no increase in flow. The coronary flow response to dobutamine measured at the time of catheterization shows promise in identifying viable myocardium in postinfarction patients.

Novel approach to rotational atherectomy results in low restenosis rates in long, calcified lesions: long-term results of the San Antonio Rotablator Study (SARS).

Ablation technique and adjunctive strategy may affect restenosis after rotational atherectomy. To minimize trauma to the vascular wall, we changed the technique of rotablation as follows: the RPM range was decreased to 140,000-160,000 RPM, the ablation was performed using a repetitive pecking motion, avoiding a decrease in the rotational speed of the burr greater than 3,000 RPM, long lesions were divided into segments and each segment was separately ablated, and the burr-to-artery ratio was intended to be approximately 0.75. To prevent coronary spasm, before and after each pass, 100-200 microg nitroglycerin and 100-200 microg verapamil i.c. boluses were administered. Adjunctive PTCA was performed using a closely sized 1.1:1 balloon-to-artery ratio with a noncompliant balloon at low pressures for 120 sec. The study incorporated 111 patients with a combined total of 146 calcified lesions. Results. A total of 31.5% of patients underwent a multivessel procedure. No deaths occurred. Q-wave MI and/or creatine kinase elevation greater than three times baseline levels occurred in 4.5% of patients. By quantitative coronary angiography (QCA), the reference vessel diameter was 3.13+/-0.59 mm, mean lesion length was 33.41+/-18.58 mm. Percent stenosis and mean luminal diameter were as follows: at baseline 75.7%+/-10.8%, or 0.76+/-0.41mm, Post-rotational atherectomy 41.5%+/-3.6%, or 1.83+/-0.43 mm, Post-PTCA 18.2%+/-11.9%, or 2.56+/-0.50 mm. Six-month angiographic follow-up was available in 64 (57.7%) pts. Net luminal gain was 1.15+/-0.76 mm, with a late luminal loss of 0.65+/-0.84 mm. The mean diameter stenosis at follow-up was 37.6%+/-28.5%, with MLD 1.91+/-1.21 mm. The binary restenosis rate was 28.1%. Therefore, modification of rotational atherectomy technique with adjunctive PTCA resulted in a favorable restenosis rate in long, calcified lesions. Cathet. Cardiovasc. Intervent. 48:48-53, 1999.

Worse six-month outcome for patients with multiple stents in a single coronary artery.

BACKGROUND: Before the "era" of optimal stent deployment, very few data concerning multiple stents in a single coronary artery showed restenosis rates up to 60%. OBJECTIVE: To evaluate the 6-month outcome of patients receiving multiple Palmaz-Schatz stents (> or =2 stents) in a single coronary artery compared to those receiving single stents. METHODS: Three hundred and forty-eight patients having multiple stents were compared to 174 patients receiving single stents during a 6-month follow-up. RESULTS: Repeat target lesion revascularization (RTLR), either repeat PTCA or CABG, was 10.4% in the single-stent group, 22.6% in the two-stent group, and 23.1% in the > or =2 stent group (p = 0.001, single versus 2 or > or =2 stents). There was not a significant difference between single stent and multiple stent groups in myocardial infarction and death during 6-month follow-up. Multivariate analysis showed multiple stents, diabetes mellitus, and type C lesion to be predictors of RTLR. CONCLUSIONS: Placement of two or more stents was associated with a significantly higher RTLR compared with single stent placement. The optimal approach to diffuse coronary artery disease remains to be defined.

Acute directional coronary atherectomy prior to stenting in complex coronary lesions: ADAPTS Study.

The purpose of this study was to determine the results of directional coronary atherectomy (DCA) combined with stenting in a high-risk patient population. The use of stenting or DCA alone for aorto-ostial lesions, total chronic occlusions, long lesions, and lesions containing thrombus is associated with lowered success and a relatively high restenosis rate. Between July 1993 and October 1996, we treated 89 lesions with the combined approach of DCA and stenting in 60 consecutive patients. Thirty-one (51.7%) patients were treated because of unstable angina, 11 (18.3%) for post-myocardial infarction (MI) angina, 3 (5.0%) for acute MI, and 15 (25.0%) patients for stable angina. A total of 43 (71.7%) patients had multivessel disease, 19 (31.7%) had undergone previous coronary artery bypass graft (CABG), and 17 (28.3%) patients had undergone multivessel revascularization. The procedure was successful in all patients; and no postprocedural deaths or emergent CABG occurred. Two patients (3.3%) had non-Q-wave MI after the procedure and 1 patient (1.7%) experienced Q-wave MI due to subacute stent closure 7 days after the procedure. During follow-up ranging from 6 months to 3 years, 2 (3.3%) patients died, 2 (3.3%) required CABG surgery, 1 (1.7%) patient had an MI, and 6 patients (10.0%) required target vessel revascularization. By the quantitative coronary angiography, the initial minimal luminal diameter (MLD) averaged 0.91+/-0.45 mm (74.7+/-11.8% stenosis) increasing to 3.80+/-0.44 mm (-6.7+/-12.1%) after the combined approach procedure. Thirty patients (50.0%) met criteria for late (> or =6 months) angiographic follow-up. Late MLD loss averaged 1.13+/-1.07 mm, for a mean net gain of 1.61+/-1.23 mm. Available angiographic follow-up evaluation showed a restenosis rate of 13.3%. A combined approach, defined as the use of both DCA and stenting, is safe and yields a low restenosis rate in high-risk patients who have lesions known to respond less favorably to stenting or DCA alone.

Real-time measurement of skin radiation during cardiac catheterization.

A novel skin dose monitor was used to measure radiation incident on maximal X-ray exposed skin during 135 diagnostic and 65 interventional coronary procedures. For the diagnostic studies (n = 135), mean skin dose was 180 +/- 64 mGy; for PTCA (n = 35), it was 1021 +/- 674 mGy, single stents (n = 25) 1529 +/- 601 mGy, and multiple stents with rotational atherectomy (n = 5) 2496 +/- 1028 mGy. The dose independently increased with more cine runs, more fluoroscopy, and greater patient weight. Physicians should consider the potential for adverse radiation exposure when planning coronary interventional cases and deciding on the X-ray mode and angles used.

Care of the elective intracoronary stent patient.

Recently, the Palmaz-Schatz coronary stent was approved by the FDA as an alternative to coronary angioplasty in the treatment of de novo native coronary stenosis. Developed by Dr. Julio Palmaz and Dr. Richard Schatz, the Palmaz-Schatz intracoronary stent design was implanted in 1987 at Brooke Army Medical Center. During the past 7 years, The University of Texas Health Science Center-San Antonio (clinical sites include University Hospital, Brooke Army Medical Center, and Audie Murphy Veterans Administration Hospital) has used this intracoronary stent to treat more than 300 patients. Nursing care for this patient population is both distinct and challenging. Successful patient outcomes require a knowledgeable staff and a team approach. This article will emphasize the nursing care and patient education required both before and after the stent procedure, as well as considerations for long-term follow-up.

Coronary artery stenting in active duty soldiers.

The treatment of coronary artery disease in young patients must take into account the long-term success of the treatment modality and the possibility of repeat interventions. Elective placement of Palmaz-Schatz coronary stents have been shown to reduce six month restenosis rates in discrete, de novo lesions in native coronary arteries albeit at a significant risk of bleeding and vascular complications. The present study was undertaken to evaluate the role of intracoronary stenting in young active duty soldiers. Between March 1988 and December 1994, fifteen active duty soldiers (age 37 to 53 years) underwent elective placement of one or more Palmaz-Schatz coronary stents at our institution. Angiographic success was 100% with no complications (acute/subacute closure, bleeding requiring transfusion, vascular repair, myocardial infarction, death, or in-hospital coronary artery bypass grafting). Six month angiographic follow-up is available in 13 patients (87%) with angiographic restenosis in one patient (8%) and no target vessel revascularization at six months. Clinical follow-up is available on all patients at a mean of 33 months (range 6-65) after the procedure. There was one death (7%) attributed to progression of coronary disease in another vessel and one patient (7%) who underwent target vessel revascularization for silent ischemia at 24 months after the procedure. These preliminary encouraging results suggest there may be a significant role for intracoronary stenting in active duty soldiers with coronary artery disease.

High balloon dilatation pressures in percutaneous transluminal coronary angioplasty are not associated with higher rate of significant complications.

To examine the results of high balloon dilatation pressures during percutaneous transluminal coronary angioplasty (PTCA), we retrospectively reviewed 482 angioplasty cases from our institution and divided them into three groups by the peak inflation pressure used during the procedure. Group one was defined by inflation pressures of 1-6 atmospheres (atm), group two by 7-12 atm, and group three by 13-20 atm. There were 166 patients in group 1 (34.4%), 235 in group 2 (48.8%), and 81 (16.8%) in group 3. The success rates were not statistically different; 90% in group 1, 96% in group 2, and 95% in group 3. Large dissections occurred in 27 patients in group 1 (16.3%), 19 in group 2 (8.1%), and 4 (4.9%) in group 3 (P > 0.006). There were no differences in the rates of death (1.2% vs. 0.9% vs. 1.2%), myocardial infarction (3.0% vs. 1.3% vs 3.7%), or in-hospital CABG (3.0% vs. 1.7% vs. 1.2%) in groups 1, 2, and 3, respectively. Six-mo target vessel revascularization rates also were not different: 19% vs. 13% vs. 18%. In summary, selectively using high balloon pressures during PTCA does not result in increased complications.