Percutaneous transluminal coronary angioplasty of the left main coronary artery in patients with rest angina

Percutaneous intervention of unprotected left main coronary artery

Successful percutaneous intervention of unprotected left main coronary artery (LMCA) in lieu of surgical revascularization represents the next wave of challenges that the field of interventional cardiology will try to overcome. Significant LMCA stenosis, commonly secondary to atherosclerosis, is seen in about 4-10% of cases presenting to the cardiac catheterization laboratory. Currently, the vast majority of these patients undergo surgical revascularization unless there are prohibitive reasons for surgical revascularization. Several challenges of percutaneous revascularization have been overcome with stents, intravascular brachytherapy, and other technical improvements. Yet, several remaining limitations of percutaneous intervention, such as in-stent restenosis, have to be improved further before randomized clinical trials of surgical and percutaneous revascularization of unprotected LMCA disease can be contemplated to establish a new standard of care.

Short- and long-term results of emergency and elective percutaneous interventions on left main coronary artery stenoses

In this prospective study, we analyzed the short- and long-term outcomes of percutaneous interventions on significant left main coronary artery (LM) stenoses. Between January 1998 and June 2000, 18 patients underwent emergency interventions on unprotected LM stenoses (group 1), while 15 patients had elective interventions on protected LM stenoses (group 2). Despite a procedural success of 88.9% in group 1, event-free in-hospital and mortality rates were 50.0% and 38.9%. After 6.4 +/- 4.4 months of follow-up, late event-free survival and mortality rates were 33.3% and 38.9%. In group 2, procedural success was 100%, with 100% event-free in-hospital survival; late event-free survival and mortality rates were 93.3% and 0% after 6.7 +/- 4.1 months of follow-up. Emergency interventions on LM stenoses remain a procedure with high acute and mid-term mortality. In spite of the high rate of major adverse cardiac events, an acceptable long-term survival can be achieved.

Unprotected left main coronary artery stenting: correlates of midterm survival and impact of patient selection

BACKGROUND

The study served to present the in-hospital and six-month clinical outcome and also the long-term survival data of a consecutive series of patients undergoing stenting for unprotected left main coronary artery (LMCA) disease.

METHODS

Revascularization with coronary bypass surgery has been generally recommended for treatment of left main coronary stenosis. Improvements in angioplasty and coronary stent techniques and equipment may result in the wider applicability of a percutaneous approach. A total of 92 consecutive patients underwent unprotected LMCA stenting between March 1994 and December 1998. For the initial 39 patients (group I) angioplasty was performed only when surgical revascularization was contraindicated. The remaining 53 patients (group II) also included patients in whom surgery was feasible. Patients were followed for 7.3 +/- 5.8 months (median 239 days; range 49 to 1,477 days).

RESULTS

Compared to group I, group II patients had higher left ventricular ejection fraction (60 +/- 12% vs. 51 +/- 16%, p < 0.01), less severe LMCA stenosis (68 +/- 12% vs. 80 +/- 10%, p < 0.001), lower surgical risk score (13 +/- 7 vs. 20 +/- 7, p < 0.001), and had angioplasty more often performed via the radial approach (88% vs. 23%, p < 0.001) with smaller guiding catheters (6F: 49% vs. 15%; 8F: 2% vs. 77%, p < 0.001). The procedural success rate was 100%. In-hospital mortality was 4% (4 deaths, 3 cardiac). During follow-up there were six deaths, 13 patients required repeat percutaneous transluminal coronary angioplasty (4 LMCA), and two required coronary artery bypass graft surgery. Estimated survival (+/- SEE) was 89 +/- 6.3% at 500 days and 85 +/- 12% at 1,000 days post-stenting. Overall mortality was 3.8% in group II and 20.5% in group I (p < 0.02).

CONCLUSIONS

Coronary stenting can be performed safely in high-risk individuals with acceptable intermediate-term outcome. It may be feasible to broaden the application of this technique in selected patients needing revascularization for left main coronary disease.

Unprotected left main coronary artery stenting: immediate and medium-term outcomes of 140 elective procedures

OBJECTIVES

We sought to evaluate immediate and late outcomes after stenting for left main coronary artery (LMCA) stenosis.

BACKGROUND

Conventional percutaneous transluminal coronary angioplasty (PTCA), for which coronary artery bypass grafting (CABG) has been the gold standard therapy for years, has yielded poor results in unprotected LMCA lesions. The development of coronary stents, together with their dramatic patency improvement provided by new antiplatelet regimens and their validation against restenosis, warrants a reappraisal of angioplasty in LMCA stenosis.

METHODS

From January 1993 to September 1998, 140 consecutive unselected patients with unprotected LMCA stenosis underwent elective stenting. Group I included 47 high-CABG-risk patients, and group II included 93 low-CABG-risk patients. Ticlopidine without aspirin was routinely started at least 72 h before the procedure and continued for one month. Patients were reevaluated monthly. A follow-up angiography was requested after six months.

RESULTS

The procedure success rate was 100%. One-month mortality was 9% (4/47) in group I and 0% in group II. A follow-up angiography was obtained in 82% of cases, and target lesion revascularization was required in 17.4%. One-year actuarial survival was 89% in the first 29 group I patients and 97.5% in the first 63 group II patients.

CONCLUSIONS

Stenting of unprotected LMCA stenosis provided excellent immediate results, particularly in good CABG candidates. Medium-term results were good, with a restenosis rate of 23%, similar to that seen after stenting at other coronary sites. Stenting deserves to be considered a safe and effective alternative to CABG in institutions performing large numbers of PTCAs.

Results of stenting of unprotected left main coronary artery stenosis in patients at high surgical risk

From March 1994 to September 1996, 39 patients underwent stenting of the unprotected left main coronary artery because of high surgical risk. Stenting appeared to improve clinical outcome, but there was a significant mortality rate at long-term follow-up.

Emergency left main stenting in the management of postcoronary bypass graft surgery (CABG) ischemia

Angioplasty has been used in the management of postcoronary bypass graft myocardial ischemia/infarction. A stent was successfully deployed in the left main artery in a patient with postcoronary bypass graft ischemia with hemodynamic instability. This case illustrates the potential use of emergency left main stenting in a selected patient with peri-operative ischemia, who was considered high risk for re-operation.

Comparison of quantitative coronary angiographic results after directional coronary atherectomy and balloon angioplasty of protected left main coronary stenosis

We compared the angiographic and clinical outcomes after directional coronary atherectomy (DCA, 13 patients) with those after conventional balloon angioplasty (BA, 21 patients) in patients with protected left main coronary artery stenosis. The initial success rate was 100% in the DCA group and 81% (17 of 21) in the BA group. Restenosis was present in 2 of 11 patients in the DCA group and 9 of 16 patients in the BA group (18% vs. 56%, P < 0.05). DCA and BA improved a minimal lumen diameter. The initial gain after DCA was greater than that after BA. At follow-up, the minimal lumen diameter was larger and the percentage diameter stenosis was smaller in the DCA group than in the BA group. The late loss and loss index were equivalent in both groups. Compared with conventional BA, DCA in protected left main coronary artery stenosis is associated with a higher angiographic success rate and provides a wider luminal diameter with reduced incidence of restenosis.

Coronary stenting of unprotected left main stem stenoses in elderly patients unsuitable for coronary surgery

We describe five patients with severe unstable angina refractory to medical management in whom coronary angiography demonstrated a severe stenosis of the left main stem. Due to severe co-existing illnesses bypass surgery was deemed inappropriate. Angioplasty to the left main stem stenosis followed by stent deployment was performed. All five patients were successfully discharged from hospital.

Angioplasty and stenting of an unprotected left main bifurcation lesion

A case of unprotected bifurcation left main disease treated on 2 occasions by angioplasty and stenting is presented. This case demonstrates the 2 main features of salvage angioplasty, namely medically refractory rest angina and refused bypass surgery. In addition, it presents short inflation time angioplasty for sole or main conduits and treating the left main as a bifurcation lesion.

Left main intervention revisited: early and late outcome of PTCA and stenting

We reviewed our experience with 28 unselected, consecutive patients undergoing left main coronary artery (LMCA) angioplasty who had been considered unsuitable for coronary artery bypass graft surgery (CABG). Fourteen patients (50%) had a protected LMCA circulation. Balloon angioplasty was performed in 11 patients (39.3%), and stents were implanted in 17 patients (60.7%). The procedure was elective in 22 patients (78.6%) and acute in the setting of myocardial infarction/cardiogenic shock in 6 (21.4%). The mean follow-up duration was 15.9 +/- 12 months. There were 5 early (before hospital discharge) and 4 late deaths (total 32.1%), 1 myocardial infarction (3.6%), 6 repeat angioplasties (21.4%), and 3 subsequent CABG (10.7%). All 5 early deaths occurred in patients with cardiogenic shock and unprotected circulation. The results of our study suggest that when patients have prohibitive surgical risks, elective LMCA angioplasty and/or stenting may be undertaken with a high procedural success rate. However, our data do not support intervention in the presence of acute myocardial infarction/cardiogenic shock.

Percutaneous treatment of protected and unprotected left main coronary stenoses with new devices: immediate angiographic results and intermediate-term follow-up

OBJECTIVES

We sought to evaluate the immediate angiographic results and intermediate-term follow-up after percutaneous treatment of left main coronary stenoses in the new device era.

BACKGROUND

Historically, balloon angioplasty of left main coronary stenoses has been associated with high procedural morbidity and poor long-term results. It is not clear whether new devices are more effective in this anatomic setting.

METHODS

Between July 1993 and July 1995, we performed initial left main coronary interventions on 46 patients (mean age 67 +/- 12 years, 26% women). Quantitative angiography was available for 42 of 46 interventions, and clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization.

RESULTS

Most interventions (42 of 46) were performed in patients with "protected" coronary stenoses to the left coronary system owing to the presence of one or more patent left main coronary grafts. Seventy-seven percent of screened patients were deemed unsuitable for repeat coronary artery bypass surgery. Procedures performed included stenting in 73% of patients (alone in 30% and after rotational atherectomy in 43%), rotational atherectomy in 58% (alone in 15% and before stenting in 43%), directional atherectomy in 4% and angioplasty alone in 7%. Initial procedural success was achieved in all interventions, with no deaths, myocardial infarctions (creatine kinase, MB fraction > 50 IU/liter) or emergent bypass surgery. Follow-up data to date (median duration 9 months, range 6 to 19) demonstrate a 98% overall survival rate and a 6-month event-free survival rate of 78% (six target vessel revascularizations [TVRs], four non-TVRs).

CONCLUSIONS

Treatment of protected left main coronary artery stenoses can be accomplished safely and effectively with new device technology. Intermediate-term follow-up demonstrates an acceptably low rate of death, myocardial infarction or repeat revascularization at 6 months and 1 year.