Myocardial blush and microvascular reperfusion following manual thrombectomy during percutaneous coronary intervention for ST elevation myocardial infarction: insights from the TOTAL trial.

AIMS: Thrombectomy during primary percutaneous coronary intervention (PPCI) for ST elevation myocardial infarction (STEMI) has been thought to be an effective therapy to prevent distal embolization and improve microvascular perfusion. The TOTAL trial (N = 10 732), a randomized trial of routine manual thrombectomy vs. PCI alone in STEMI, showed no difference in the primary efficacy outcome. This angiographic sub-study was performed to determine if thrombectomy improved microvascular perfusion as measured by myocardial blush grade (MBG). METHODS AND RESULTS: Of the 10 732 patients randomized, 1610 randomly selected angiograms were analysable by the angiographic core laboratory. Primary outcomes included MBG and post-PCI thrombolysis in myocardial infarction (TIMI) flow grade. Secondary outcomes included distal embolization, PPCI complications, and each component of the complications. The primary end point of final myocardial blush (221 [28%] 0/1 for thrombectomy vs. 246 {30%} 0/1 for PCI alone group, P = 0.38) and TIMI flow (712 [90%] TIMI 3 for thrombectomy vs. 733 [89.5%] TIMI 3 for PCI alone arm, P = 0.73) was similar in the two groups. Thrombectomy was associated with a significantly reduced incidence of distal embolization compared with PCI alone (56 [7.1%] vs. 87 [10.7%], P = 0.01). In multivariable analysis, distal embolization was an independent predictor of mortality (HR 3.00, 95% CI 1.19-7.58) while MBG was not (HR 2.73, 95% CI 0.94-5.3). CONCLUSIONS: Routine thrombectomy during PPCI did not result in improved MBG or post-PCI TIMI flow grade but did reduce distal embolization compared with PCI alone. Distal embolization and not blush grade is independently associated with mortality.

Long-term outcomes using a two-stent technique for the treatment of coronary bifurcations.

BACKGROUND: The crush and culotte are probably the most common two-stent techniques utilized for percutaneous coronary intervention (PCI) of complex bifurcation lesions. Long-term outcome associated with the utilization of these techniques is unknown. Our objective was to evaluate the long-term outcomes after bifurcation PCI utilizing these 2 techniques with a prospective PCI registry. METHODS: Between 11/1/2003 and 12/31/2007, 360 patients were treated with either crush (n=304) or culotte (n=56). Primary outcome was the occurrence of major adverse cardiac events (MACE) defined as the composite of death, myocardial infarction and target vessel revascularization. The major secondary outcome measure was MACE or occurrence of CCS Class ≥ 2 angina. RESULTS: After a median follow-up of 4.1 years (3.0-5.1), the occurrence of MACE was 23.9%. MACE or CCS Class ≥ 2 angina occurred in 27.5% of patients. Multivariable analysis revealed that creatinine clearance <60 ml/min (odds-ratio [OR]=1.71, 95% CI 1.08-2.71; p=0.022) and left ventricular ejection fraction <40% (OR=2.14, 95% CI 1.21-3.79; p=0.008) were independent predictors of MACE or CCS Class ≥ 2 angina. A larger main vessel reference diameter (OR=0.57, 95% CI 0.61-0.92), bifurcation angle <50% (OR=0.59, 95% CI 0.35-0.92) and a final kissing-balloon inflation (OR=0.75, 95% CI 0.35-0.99) were associated with a lower risk of MACE or CCS Class ≥ 2 angina. CONCLUSIONS: Application of the crush and culotte techniques is associated with efficacy and safety at long-term follow-up. Bifurcation angle, a final kissing balloon inflation and vessel reference diameter are important variables that impact on very long-term outcomes.

A calcified neointima--"stent" within a stent.

De novo atherosclerosis arising within a coronary stent is rare and generally occurs many years after stent deployment. We describe a case of restenosis in a patient presenting with angina 8 years after original stent deployment. Intravascular ultrasound greyscale imaging and virtual histology demonstrated that this "neointima" was calcified.

Long-term outcomes after percutaneous coronary intervention of bifurcation narrowings.

The optimal approach to percutaneous coronary intervention (PCI) of bifurcation lesions remains unclear, reflecting lack of long-term follow-up and heterogeneity of lesions encountered. We evaluated the long-term outcome of patients undergoing bifurcation PCI followed in the prospective bifurcation registry at the University Health Network, Toronto, Ontario, Canada. Of 526 patients undergoing bifurcation PCI between November 2003 and March 2005, most (n = 406) were treated by main vessel stenting only (n = 266) or crush/culotte stenting (n = 140). After median follow-up of 26.5 months, major adverse cardiac events (MACEs) and Canadian Cardiovascular Society class > or =2 angina occurred in 28.5% and 22.3% of patients in these groups, respectively (p = 0.190), whereas MACE rates were 20.8% for main vessel stenting and 18.7% for crush/culotte stenting (p = 0.670). A low bifurcation angle was associated with better outcomes in the crush/culotte group but had no effect on outcome of patients treated with main vessel stenting only. Use of crush/culotte techniques independently predicted freedom from MACEs or Canadian Cardiovascular Society class > or =2 angina compared with main vessel stenting only (odds ratio 0.55, 95% confidence interval 0.32 to 0.94, p = 0.029). In conclusion, the use of crush/culotte stenting is safe, with efficacy and MACE rates being similar to main vessel stenting alone. Our observations regarding the effect of lesion characteristics such as bifurcation angle and extent of side branch disease on outcome underscore the need for randomized trials that are inclusive of patients with complex side branch disease.

Prediction of distal embolization during percutaneous coronary intervention in saphenous vein grafts.

Distal protection devices have been proved to decrease distal embolization and improve outcome in unselected patients undergoing percutaneous coronary intervention (PCI) in saphenous vein grafts (SVGs). However, it remains uncertain whether distal protection is necessary in all patients. We investigated whether clinical or angiographic variables can predict distal embolization and, hence, need for a distal protection device. Fifty-eight consecutive SVGs that underwent PCI with a FilterWire distal protection device were studied. After the procedure, the FilterWire was fixed in formalin and photographed, and embolic debris area (square millimeters) was quantified by semi-automated edge-detection analysis. Debris area was correlated with 6 prespecified variables: clinical presentation, SVG age, reference lumen diameter, plaque volume, SVG degeneracy, and presence of a filling defect. Embolic debris was identified in 57 of 58 grafts (98%). Median debris area was 4.0 mm(2) (range 0.0 to 25.1). None of the prespecified variables predicted the occurrence of distal embolization or the amount of captured embolic debris. In conclusion, distal embolization during SVG PCI is universal. Embolic burden cannot be predicted by clinical or angiographic variables, and embolic protection should be used in all patients.

Predictors of long-term outcome after crush stenting of coronary bifurcation lesions: importance of the bifurcation angle.

OBJECTIVES: We hypothesized that the bifurcation angle (BA) may affect the outcome of crush stenting (CS) of bifurcation lesions and thus set out to determine the effect of the BA on outcome of patients undergoing coronary bifurcation CS. METHODS: Of 538 bifurcation PCI cases performed between November 2003 and March 2005, 133 were performed using CS (n = 56), balloon CS (n = 71), or reverse CS (n = 6). Patients were divided into low-angle and high-angle groups using the median BA as the cut point. RESULTS: The median BA was 50 degrees. High-angle patients were more likely to be women (33% vs 15%, P = .02), with a prior percutaneous coronary intervention (26% vs 12%. P = .05) and coronary artery bypass grafting (15% vs 5%, P = .05). Procedural success was 98.5% in the low-angle and 95.4% in the high-angle group (P = nonsignificant). Two high-angle patients had acute stent thrombosis, and 1 died in hospital. Four additional high-angle patients (6.1%) and 1 low-angle patient (1.5%) died (P = nonsignificant) during follow-up. Major adverse cardiac events (MACE) occurred more frequently in the high-angle group (22.7% vs 6.2%, P = .007). Bifurcation angle > or = 50 degrees (P = .004), no final kissing balloon inflation (P = .012), and creatinine clearance < 40 mL/min (P = .031) independently predicted MACE. CONCLUSIONS: Bifurcation angle > or = 50 degrees is an independent predictor of MACE after bifurcation CS, in addition to no final kissing balloon inflation and severe renal dysfunction. A high BA confers a setting of increased turbulent flow that is further exacerbated by suboptimal treatment of the crushed side-branch stent. Further study to improve outcome in this subset of patients is warranted.

Predictors of angiographic restenosis after coronary intervention in patients with diabetes mellitus.

BACKGROUND: Patients with diabetes mellitus are particularly prone to restenosis after percutaneous coronary intervention. An exploratory, nested, case-control study was undertaken to identify clinical, lesional, and procedural predictors of angiographic restenosis in these patients. METHODS: Seventy-five patients with diabetes mellitus with 86 coronary lesions were selected from a larger population of 217 patients who had undergone 6-month angiographic follow-up after a first, successful balloon angioplasty (PTCA) or stent implantation procedure. Data collection was by patient interview and review of hospital database and other medical records. All angiograms were analyzed with quantitative coronary angiography, and restenosis was defined as a >or=50% diameter reduction at the treated site. A multivariate analysis of 10 prespecified explanatory variables, derived from a literature review, was performed on a per-lesion basis. RESULTS: There were 45 patients (53 lesions) with restenosis and 30 patients (33 lesions) without restenosis. Univariate predictors of binary restenosis were periprocedural glycosylated hemoglobin level, vessel reference diameter, PTCA, and larger final balloon size to reference artery diameter ratio. Multiple logistic regression identified poor glycemic control (odds ratio [OR] 3.03, 95% CI 1.06-8.65, P =.038), small vessel reference diameter (OR 3.41, 95% CI 1.17-9.95, P =.025), and mode of intervention (OR 3.12, 95% CI 1.08-9.00, P =.036) as independent risk factors. Vessel reference diameter appeared to be an important effect modifier of the association between type of intervention and angiographic outcome, with stenting no longer superior to PTCA in patients with diabetes mellitus who had vessels <2.87 mm in diameter (P =.054). CONCLUSION: Poor glycemic control, vessel size, and PTCA were independent predictors of restenosis in patients with diabetes mellitus. It is possible that improved periprocedural glycemic control, in addition to stenting, may reduce the restenosis rate in these patients.

The role of intravascular ultrasound in the diagnosis and treatment of patients with coronary artery disease.

Approximately 95% of the coronary vasculature is atherosclerotic before lesions are visible by coronary angiography. Intravascular ultrasound assesses the burden of coronary atherosclerosis, as well as clarifying the anatomical and physiological characteristics of ambiguous lesions.