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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.

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.

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.

To evaluate technical differences and angiographic response of saphenous vein bypass graft angioplasty in comparison to native coronary arteries, we retrospectively analyzed 54 patients undergoing this procedure at The Toronto Hospital between February 1988 and May 1993. These subjects were temporally matched to a cohort of successful native coronary angioplasties, with comparison of technical parameters, pre-existing qualitative/quantitative (Cardiac Measurement System) stenotic morphology, and angiographic response; including changes in minimum lumen diameter. Saphenous bypass graft angioplasty utilized larger balloons (CABG, 3.27 +/- 0.65 vs. native, 2.90 +/- 0.37 mm, P < .05), and higher inflation pressures (CABG, 10.1 +/- 3.7 vs. native, 8.8 +/- 2.5 atm, P < .05), although in a relative sense, balloon/artery ratios were similar (CABG, 1.09 +/- 0.20 vs. native, 1.03 +/- 0.15, pNS). Pre-procedural bypass graft lesions were more complex, with more frequent ACC/AHA type B1 lesions [CABG, 24/54 (44%) vs. native, 16/54 (30%), P < .05] and luminal thrombus [CABG, 17/54 (31%) vs. native, 6/54 (11%), P < .05]. Quantitative angiography revealed larger "reference" diameters within saphenous veins (CABG, 3.41 +/- 0.76 vs. native, 3.04 +/- 0.51 mm, P < .05), although minimum lumen diameter was less severe (CABG, 0.83 +/- 0.41 vs. native, 0.77 +/- 0.36, P < .05). In terms of balloon angioplasty response, greater improvement in luminal diameter was seen in bypass graft lesions (CABG, 1.55 +/- 0.53 vs. native, 1.32 +/- 0.44 mm, P < .05), with the largest changes within the "body" of the saphenous vein (ostial, 1.53 +/- 0.37; body, 1.68 +/- 0.50; anastomosis, 1.37 +/- 0.57 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

To examine physician bias in reporting percutaneous transluminal coronary angioplasty (PTCA) results and analyze this potential source of errors, and to examine the ability to estimate absolute lumen diameters visually, the authors reviewed 56 successful PTCAs from their institution. Pre- and postprocedural cineangiograms were blindly reviewed by an experienced consensus panel (three members) and compared with the interventional cardiologist's reported outcome (percentage diameter stenosis) and quantitative coronary angiography (QCA) using the Cardiac Measurement System. Staff cardiologists significantly overestimated pre-PTCA stenosis severity (staff 83.7 versus panel 75.2%, P < 0.05) while underestimating residual narrowing (staff 18.4 versus panel 22.8%, P < 0.05), thus exaggerating overall angioplasty benefit (staff -65.3 versus panel -52.4%, P < 0.05). The cumulative error varied greatly among individual staff members (3.4 to 18.0%). Despite these findings, the consensus panel accurately identified pre-PTCA minimum lumen diameter, as measured by quantitative angiography (panel 0.66 versus QCA 0.67 mm, not significant), although they tended to overestimate absolute postprocedural luminal dimensions (panel 2.28 versus QCA 2.00 mm, P < 0.05) and thereby ultimate changes in minimum lumen diameter (panel 1.62 versus QCA 1.33 mm, P < 0.05). Therefore, substantial bias exists in the reporting of PTCA outcomes, which tends to magnify the perceived benefits of the procedure. Well-trained observers can accurately estimate pre-PTCA absolute lumen diameters, although difficulties occur in evaluating residual dimensions.

We evaluated intraprocedural "elastic recoil" in 25 patients (22 men and 3 women) undergoing directional coronary atherectomy (DCA) of left anterior descending stenoses, and compared these with 25 temporally-matched (14 men and 11 women) patients having balloon angioplasties (PTCA). Quantitative arteriography was performed using the Coronary Measurement System (Leiden, The Netherlands), with "elastic recoil" defined as the difference in maximum device or balloon size minus residual minimum diameter. In addition, we determined the effects of relative device size, specific anatomic location (proximal/mid artery), lesion length, eccentricity (symmetry index), and dystrophic calcification on acute "recoil" severity after both procedures. Although initial coronary stenoses were similar (minimum stenotic diameter, DCA = 0.59 +/- 0.20 mm versus PTCA = 0.55 +/- 0.23 mm, p = NS), less "elastic recoil" was observed after atherectomy (DCA = 0.83 +/- 0.57 mm versus PTCA = 1.26 +/- 0.56 mm, p < 0.01), and this was confirmed by absolute recoil/maximum device size ratios (DCA = 23.5 +/- 16.0% versus PTCA = 41.6 +/- 13.8%, p < 0.01). Acute "elastic recoil" was also influenced by maximum device size/"normal" coronary artery ratios [(ratio < 0.9, DCA = 0.26 +/- 0.10 mm versus PTCA = 0.84 +/- 0.13 mm, p < 0.01); (ratio 0.9 to 1.1, DCA = 0.69 +/- 0.41 mm versus PTCA 0.75 +/- 0.32 mm, p = NS); (ratio > 1.1, DCA = 1.09 +/- 0.64 mm versus PTCA = 1.59 +/- 0.48 mm, p < 0.05)].(ABSTRACT TRUNCATED AT 250 WORDS)

To assess the immediate outcome of directional coronary atherectomy (DCA) versus standard balloon angioplasty (PTCA) in de novo left anterior descending coronary stenoses, 25 consecutive atherectomies (22 men, 3 women) performed at The Toronto Hospital, between July 1990 and March 1991 were compared with 25 (14 men, 11 women) temporally matched successful angioplasties. Coronary stenoses were analyzed by quantitative arteriography, using the Coronary Measurement System (Leiden, The Netherlands), with estimation of transstenotic hemodynamics by fluid dynamic equations. Before and after procedure qualitative blood flow (TIMI criteria) was also evaluated, as was intimal haziness and coronary dissection. In comparison to PTCA, coronary atherectomy produced less residual minimum stenotic diameter (DCA, 2.75 +/- 0.55 vs PTCA, 1.70 +/- 0.44 mm, p < 0.001), and relative percent diameter stenosis (DCA, 17.9 +/- 10.7 vs PTCA, 34.4 +/- 10.7 percent, p < 0.001), with less transstenotic obstructive gradient (DCA, 0.2 +/- 0.2 vs PTCA, 1.0 +/- 1.5 mm Hg, p < 0.05), and greater estimated stenotic flow reserve (DCA, 4.86 +/- 0.15 vs PTCA, 4.50 +/- 0.48 x baseline, p < 0.05). Coronary atherectomy "normalized" TIMI flow patterns in virtually all patients (DCA, 2.96 +/- 0.20 vs PTCA, 2.72 +/- 0.45, p < 0.05), while creating less intimal haziness (DCA, 10/25 [40 percent] vs PTCA, 23/25 [92 percent], p < 0.01), and coronary dissection (DCA, 6/25 [24 percent] vs PTCA, 16/25 [64 percent], p < 0.05). Therefore, when compared with standard balloon angioplasty, DCA produces less residual stenosis, better transstenotic hemodynamics, while decreasing the frequency of coronary artery damage, in de novo left anterior descending stenoses.

To examine the morphologic features of stenotic segments developing abrupt coronary occlusion during elective angioplasty, 36 cases occurring at the Toronto General Hospital between January 1985 and December 1989 were evaluated and compared with a temporally matched successful group. Quantitative arteriographic analysis was performed, including estimates of arterial tortuosity (proximal-stenotic axis deviation) and qualitative assessment for dystrophic calcification, residual lumen eccentricity and intimal irregularity. Acute occlusion occurred more frequently in the mid-arterial segment (success, mid 14 versus occlusion 21, P less than 0.05). Stenosis severity assessed by minimum stenotic diameter did not affect outcome (success 0.42 mm versus occlusion 0.37 mm, not significant or relative percentage diameter stenosis (success 86% versus occlusion 86%, not significant). Average stenotic length was equal (success 14.3 mm versus occlusion 13.6 mm, not significant), although coronary arterial tortuosity was increased in the acute occlusion group (success 27 degrees versus occlusion 34 degrees, P less than 0.05). Residual lumen eccentricity score was increased (success 1.66 versus occlusion 2.69, P less than 0.001), with greater dystrophic calcification in the occlusion group (success 0.31 versus occlusion 0.69, P less than 0.05). In addition, intimal irregularity was significantly greater (success 1.65 versus occlusion 2.5, P less than 0.001), although major arterial side branches failed to predict outcome (success 28% versus occlusion 36%, not significant). These data suggested that a mid-coronary anatomic location, arterial tortuosity, lumen eccentricity, dystrophic calcification and intimal irregularity increased the probability of acute occlusion during elective coronary angioplasty.