Impact of stents on clinical outcomes in percutaneous left main coronary artery revascularization

[Unprotected left main coronary artery stenting: immediate and medium-term outcomes of 24 procedures]

OBJECTIVES

We have examined the immediate and long-term patient outcomes following angioplasty of unprotected left main coronary artery stenoses.

BACKGROUND

Coronary disease of the unprotected left main artery is considered as an absolute contraindication for percutaneous intervention. Recently, several studies have reported good results with unprotected left main coronary artery stenting when surgical revascularization was contraindicated.

METHODS

From October 2004 to June 2006, 24 patients with a contraindication to surgery and with unprotected left main coronary artery stenoses received stents. Patients were surveyed at one, six and 12 months with telephone interviews.

RESULTS

The procedure's success rate was 100%. The percentage of stenosis and minimum lumen diameter (MLD) were respectively 63.4% (+/-15.4) and 1.1mm (+/-0.5) before procedure; 13.8% (+/-10.2) and 3.2mm (+/-0.5) after angioplasty. The size of stents averaged 3.79 mm (+/-0.46) with an average 1.04 stents per patient. During follow up, two deaths occurred (8.3%). No intrastent restenosis was found.

CONCLUSIONS

Stenting of unprotected left main coronary artery stenoses may be a safe and effective alternative to coronary artery bypass especially when surgical revascularization is contraindicated. However, further studies with larger patient populations are needed to assess the late outcome and to clarify the relevance of percutaneous intervention compared to surgery.

Left main coronary artery stenosis: state-of-the-art

Patients with stenosis of the left main coronary artery present difficult challenges. The risks associated with this lesion have been known since the early days of angiography when patients were found to have increased mortality during follow-up. This information led to the general guidelines that surgical revascularization should be considered the treatment of choice in patients with significant left main coronary artery stenosis. Current advances in invasive cardiology have brought important information to the field. Intravascular ultrasound is now used routinely to evaluate angiographically indeterminate lesions with criteria now set forward as to what constitutes an indication for revascularization. Stents have even further dramatically changed the landscape. There are substantial issues, however, that need to addressed. These include the following: (1) the effect of specific lesion location on outcome - it is known that patients with distal bifurcation left main disease have worse outcome; (2) the potential for subacute thrombosis of the left main coronary artery; (3) the impact of left ventricular function and patient comorbidities irrespective of the degree and location of left main coronary artery stenosis; and (4) the risk-benefit ratio of stenting versus coronary artery bypass graft surgery. These issues are currently being addressed in two seminally important trials including the SYNTAX trial, which randomizes patients with left main and/or three-vessel disease to either coronary artery bypass graft surgery or a TAXUS drug-eluting stent. This trial is in the final stages of patient recruitment and will have important implications for the field. The other trial is the COMBAT trial, which is focused exclusively on left main coronary artery stenosis and randomizes patients with left main coronary artery disease either to a Sirolimus-eluting stent (Cypher, Johnson and Johnson Cordis, USA) or to coronary artery bypass graft surgery. The field of left main coronary artery disease continues to expand in terms of the evidence available for optimal patient evaluation and selection of treatment modalities.

[Left main coronary artery angioplasty: report of five cases illustrating the current indications]

OBJECTIVES

The purpose of our study is to illustrate by five original observations the various situations where the stenting of the left main coronary artery can be proposed in alternative to aortocoronary bridging with encouraging results in short- and long-term.

MATERIALS AND METHODS

We report a retrospective study relating to five cases with left main disease treated by stenting between 1996 and 2002 at our institution. In two cases the left main stem was unprotected. In two other cases, the left main trunk was protected. And the last case was an emergency stenting for an iatrogenic dissection of the left main coronary artery.

RESULTS

The stenting was carried out successfully among the five patients without major in-hospital complication. During the follow-up of 29 months at mean, no death was deplored, and no target lesion revascularization was required on the left main coronary artery (with a left main trunk permeable on three coronarographic controls).

CONCLUSIONS

In the light of these results, and basing on the published data, we conclude that stenting for the left main coronary disease may be a safe and effective alternative to coronary artery bypass surgery in particular cases among "selected" patients (refusal or surgical contraindication, protected left main coronary artery, spontaneous or iatrogenic acute occlusion of the left main coronary artery).

Distal Left Main Coronary Disease Is a Major Predictor of Outcome in Patients Undergoing Percutaneous Intervention in the Drug-Eluting Stent Era

OBJECTIVES

This study sought to investigate whether the anatomical location of the disease carries prognostic implications in patients undergoing drug-eluting stent (DES) implantation for the left main coronary artery (LMCA) stenosis.

BACKGROUND

Liberal use of DES, compared with a bare metal stent (BMS), has resulted in an improved outcome in patients undergoing LMCA intervention. However, the overall event rate in this subset of patients remains high, and alternative tools to risk-stratify this population beyond conventional surgical risk status would be desirable.

METHODS

From April 2002 to June 2004, 130 patients received DES as part of the percutaneous intervention for LMCA stenoses in our institution. Distal LMCA disease (DLMD) was present in 94 patients. They were at higher surgical risk and presented with a greater coronary disease extent compared with patients without DLMD.

RESULTS

After a median of 587 days (range 368 to 1,179 days), the cumulative incidence of major adverse cardiac events (MACE) was significantly higher in patients with DLMD at 30% versus 11% in those without DLMD (hazard ratio [HR] 3.42, 95% confidence interval [CI] 1.34 to 9.7; p = 0.007), mainly driven by the different rate of target vessel revascularization (13% and 3%; HR 6, 95% CI 1.2 to 29; p = 0.02). After adjustment for confounders, DLMD (HR 2.79,95% CI 1.17 to 8.9; p = 0.032) and surgical risk status (HR 2.18,95% CI 1.06 to 4.5; p = 0.038) remained independent and complementary predictors of MACE.

CONCLUSIONS

Distal LMCA disease carries independent prognostic implications, and it may help in selecting the most appropriate patient subset for LMCA intervention beyond the conventional surgical risk status in the DES era.

Prevalence of unfavorable angiographic characteristics for percutaneous intervention in patients with unprotected left main coronary artery disease

OBJECTIVES

The goal of this study was to determine the proportion of patients with left main coronary disease (LMCD) with unfavorable characteristics for percutaneous coronary intervention (PCI).

BACKGROUND

Published series suggest that LMCD can be treated percutaneously, however, the proportion of patients in whom PCI is an option based on angiographic criteria is unknown.

METHODS

In 13,228 consecutive coronary angiograms, 476 (3.6%) patients had < or =60% stenosis of the left main. In 232 patients with unprotected LMCD, the clinical characteristics and angiograms were reviewed with six features chosen as "unfavorable" for PCI: (1) Bifurcation LMCD, (2) occlusion of a major coronary, (3) ejection fraction <30%, (4) occlusion of a dominant RCA, (5) left dominant circulation, and (6) coexisting three-vessel disease. Treatment modality and 1 year mortality were determined.

RESULTS

The mean age was 69 years and 68% were male. Unfavorable characteristics were common with at least one unfavorable characteristic seen in 80%. Bifurcation disease was the most common unfavorable characteristic observed (53%) and coexisting three-vessel disease was seen in 38%. Treatment consisted of CABG in 205 (88%), medical therapy in 24 (10%) and PCI in 3 (1%). Among patients referred for CABG, 1 year survival was 88% with similar rates of survival for those with favorable characteristics (86%) compared to those with at least one unfavorable characteristic (88%).

CONCLUSIONS

Most patients with LMCD have at least one unfavorable characteristic for PCI suggesting that PCI may be a technically difficult option for most patients with LMCD.

Percutaneous intervention for unprotected left main disease prior to explantation of a left ventricular assist device

Percutaneous coronary intervention of unprotected left main coronary arterial disease is an alternative to surgical revascularization in selected patients. In this report, a patient with an implanted left ventricular assist device (LVAD) underwent successful coronary intervention prior to its planned removal. The implanted LVAD clearly assisted the technical performance of the intervention.

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 for cardiac allograft vasculopathy

Cardiac allograft vasculopathy is the leading cause of death after the first year of transplantation. Treatment outcomes with medication, balloon angioplasty, bypass surgery, and retransplantation have been disappointing. We present our initial experience with stenting of the left main coronary artery in the setting of allograft vasculopathy.

Stent placement for non-STRESS/BENESTENT lesions: a critical review

Stenting lesions with favorable characteristics as required for inclusion in the STRESS/BENESTENT trials have yielded superior results to that of PTCA alone. Results for less favorable lesions such as in small vessels, diffuse disease, ostial disease, and saphenous vein grafts are less well established. This review seeks to analyze available data for stent placement in this subset of non-STRESS/BENESTENT lesions.