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. Cathet. Cardiovasc. Diagn. 44:138–141, 1998. © 1998 Wiley-Liss, Inc.     

Comparative analysis of early and late angiographic outcomes using two quantitative algorithms in the Balloon versus Optimal Atherectomy Trial (BOAT)

Although substantial intersystem variability has been shown among several commercially available quantitative angiographic (QA) analysis algorithms, no previous study has compared the angiographic findings using 2 different QA systems performed at the same central angiographic laboratory. The purpose of this study was to compare the early and late QA results obtained with the CMS (MEDIS) and ARTREK (ImageComm) QA systems in the Balloon versus Optimal Atherectomy Trial. Directional atherectomy (n = 496) or balloon angioplasty (n = 490) was performed in 986 patients; late QA follow-up was available in 767 patients (77.7%). QA analysis was performed by 2 independent observers using the CMS and ARTREK systems. Correlation between the 2 QA systems for baseline measurements was good (Pearson’s R = 0.78), although the CMS system resulted in larger baseline reference diameter (RD) (3.22 ± 0.45 vs 3.07 ± 0.40 mm; p <0.0001) and baseline minimal lumen diameters (MLD) (1.05 ± 0.35 vs 0.92 ± 0.32; mm p <0.0001) than the ARTREK system. The final and follow-up RD (+0.17 and + 0.11 mm, respectively) were also larger using the CMS system. In contrast, the final and follow-up measurements of MLD and percent diameter stenosis were not significantly different using the 2 QA systems. The QA system did not affect the abilily to detect a difference in restenosis rates (>50% follow-up diameter stenosis) between the 2 treatment groups (CMS, directional atherectomy [31.8%]; balloon angioplasty [40.5%]; p = 0.013 and ARTREK, directional atherectomy [33.9%], balloon angioplasty [41.3%]; p = 0.036). Only lesion irregularity contributed to the difference in baseline measurements of MLD and percent diameter stenosis. We conclude that important differences in measurements of RD, baseline MLD, and percent diameter stenosis were noted using the CMS and ARTREK systems. Both systems, however, were able to detect a treatment benefit associated with directional atherectomy in BOAT. The comparability of other angiographic systems will require similar evaluation in other studies.     

Adjunctive stent implantation following directional coronary atherectomy in patients with coronary artery disease

Objectives. This prospective case-control study evaluated the acute and long-term results of stent implantation preceded by debulking of the plaque by means of directional coronary atherectomy.

Background. In comparison with balloon angioplasty, intracoronary stenting produces a larger luminal diameter, maintains artery patency and reduces the incidence of restenosis. Optimal stent deployment is a pivotal factor for achieving the best results, but the bulk of the atherosclerotic plaque opposes stent expansion and may limit the success of the procedure. Debulking of the plaque may provide a better milieu for optimal stent deployment.

Methods. Directional coronary atherectomy followed by a single Palmaz-Schatz stent implantation was attempted in 100 patients. The successes, complications and angiographic results of the combined procedure were evaluated both acutely and during follow-up. Matched patients undergoing successful Palmaz-Schatz stent implantation alone during the same period served as controls.

Results. Atherectomy followed by stent implantation was performed in 94 patients with 98 lesions; periprocedural complications were observed in four cases. The stenosis diameter decreased from 76 ± 9% at baseline to 30 ± 13% after atherectomy (p < 0.0001), and 5 ± 9% after stent implantation (p < 0.0001); it increased to 27 ± 15% at 6-month angiography (p < 0.0001). During the 14 ± 10 months of follow-up, none of the patients died or experienced myocardial infarction, but three patients underwent target lesion revascularization. The patients undergoing stent implantation alone achieved smaller acute gains, tended to have a higher late lumen loss, had a higher restenosis rate (30.5% vs. 6.8%, p < 0.0001) and showed a greater incidence of clinical events during follow-up (p < 0.0001).

Conclusions. Debulking atherosclerotic lesions by means of directional coronary atherectomy before stent implantation is a safe procedure with a high success rate and a low incidence of restenosis at follow-up.     

Quantitative angiography after directional coronary atherectomy

OBJECTIVE--To assess by quantitative analysis the immediate angiographic results of directional coronary atherectomy. To compare the effects of successful atherectomy with those of successful balloon dilatation in a series of patients with matched lesions. DESIGN--Case series. SETTING--Tertiary referral centre. PATIENTS--62 patients in whom directional coronary atherectomy was attempted between 7 September 1989 and 31 December 1990. INTERVENTIONS--Directional coronary atherectomy. MAIN OUTCOME MEASURES--Increase in minimal luminal diameter of coronary artery segment. RESULTS--Angiographic success on the basis of intention to treat was obtained in 54 patients (87%). In four patients the lesion could not be crossed by the atherectomy device; all four had an uneventful conventional balloon angioplasty. Four of the 58 patients who underwent atherectomy were subsequently referred for coronary bypass surgery because of failure or complications; three of them sustained a transmural infarction. In the successful cases, coronary atherectomy resulted in an increase in the minimal luminal diameter from 1.1 mm to 2.5 mm with a concomitant decrease of the diameter stenosis from 62% to 22%. In the subset of 37 patients in which the changes induced were compared with conventional balloon angioplasty atherectomy increased the minimal luminal diameter more than balloon angioplasty (1.6 v 0.8 mm; p less than 0.0001). Conventional histology showed media or adventitia in 26% of the atherectomy specimens. In hospital complications occurred in six patients who had undergone a successful procedure: two transmural infarctions, two subendocardial infarctions, one transient ischaemia attack, and one death due to delayed rupture of the atherectomised vessel. All patients were clinically evaluated at one and six months. One patient had persisting angina (New York Heart Association class II), one patient sustained a myocardial infarction, one patient underwent a percutaneous transluminal coronary angioplasty for early restenosis, and one patient underwent coronary bypass surgery because of a coronary aneurysm formation. At six months 80% (36/47) of the patients were symptom free. CONCLUSIONS--Coronary atherectomy achieved a better immediate angiographic result than balloon angioplasty; however, in view of the complication rate in this preliminary series, which may be related to a learning curve, a randomised study is needed to show whether this procedure is as safe as a conventional balloon angioplasty.     

Quantitative angiography after directional coronary atherectomy.

OBJECTIVE--To assess by quantitative analysis the immediate angiographic results of directional coronary atherectomy. To compare the effects of successful atherectomy with those of successful balloon dilatation in a series of patients with matched lesions. DESIGN--Case series. SETTING--Tertiary referral centre. PATIENTS--62 patients in whom directional coronary atherectomy was attempted between 7 September 1989 and 31 December 1990. INTERVENTIONS--Directional coronary atherectomy. MAIN OUTCOME MEASURES--Increase in minimal luminal diameter of coronary artery segment. RESULTS--Angiographic success on the basis of intention to treat was obtained in 54 patients (87%). In four patients the lesion could not be crossed by the atherectomy device; all four had an uneventful conventional balloon angioplasty. Four of the 58 patients who underwent atherectomy were subsequently referred for coronary bypass surgery because of failure or complications; three of them sustained a transmural infarction. In the successful cases, coronary atherectomy resulted in an increase in the minimal luminal diameter from 1.1 mm to 2.5 mm with a concomitant decrease of the diameter stenosis from 62% to 22%. In the subset of 37 patients in which the changes induced were compared with conventional balloon angioplasty atherectomy increased the minimal luminal diameter more than balloon angioplasty (1.6 v 0.8 mm; p less than 0.0001). Conventional histology showed media or adventitia in 26% of the atherectomy specimens. In hospital complications occurred in six patients who had undergone a successful procedure: two transmural infarctions, two subendocardial infarctions, one transient ischaemia attack, and one death due to delayed rupture of the atherectomised vessel. All patients were clinically evaluated at one and six months. One patient had persisting angina (New York Heart Association class II), one patient sustained a myocardial infarction, one patient underwent a percutaneous transluminal coronary angioplasty for early restenosis, and one patient underwent coronary bypass surgery because of a coronary aneurysm formation. At six months 80% (36/47) of the patients were symptom free. CONCLUSIONS--Coronary atherectomy achieved a better immediate angiographic result than balloon angioplasty; however, in view of the complication rate in this preliminary series, which may be related to a learning curve, a randomised study is needed to show whether this procedure is as safe as a conventional balloon angioplasty.     

Effect of prior coronary restenosis on the risk of subsequent restenosis after stent placement or directional atherectomy

Lesions that have developed restenosis after a prior intervention may be more likely to develop restenosis after subsequent percutaneous interventions. To determine if this is an independent effect, the clinical characteristics and immediate angiographic outcomes of 179 prior restenosis lesions were compared with those of 254 primary lesions after stenting or directional atherectomy. Six-month angiographic follow-up was obtained for 79% of successfully treated lesions. Univariable and muttivariable logistic regression was used to determine how binary restenosis (defined as -50% diameter stenosis at follow-up) was influenced by postprocedure luminal diameter, left anterior descending artery location, diabetes mellitus, as well as prior restenosis. At 6-month follow-up, prior restenosis lesions had a significantly smaller late diameter (1.77 vs 2.18 mm, p < 0.001), more absolute late loss (1.35 vs 1.14 mm, P = 0.051), a higher loss index (0.58 vs 0.45, p < 0.02), and a higher binary restenosis rate (37.3% vs 24.4%, P = 0.01). Whereas univariable analysis revealed that left anterior descending artery location, diabetes mellitus, postprocedure luminal diameter < 3.1 mm, and prior restenosis were each strong predictors of binary restenosis (all p < 0.02), muttivariable analysis showed that after adjustment for left anterior descending artery location, diabetes, and postprocedure luminal diameter, prior restenosis was no longer an independent predictor of restenosis (odds ratio 1.57, 95% confidence interval 0.95–2.60, P = 0.073). In conclusion, although prior restenosis lesions do show more restenosis than primary lesions, much of this effect is due to preselection of a population enriched in other known factors that predispose to restenosis.     

Randomized trials of directional coronary atherectomy: Implications for clinical practice and future investigation

Objectives. This study compared and contrasted the randomized trials of directional atherectomy and coronary angioplasty for de novo native coronary artery lesions.Background. The results of two randomized trials, the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) and the Canadian Coronary Atherectomy Trial (CCAT), comparing initial and intermediate-term outcome of directional coronary atherectomy and conventional coronary angioplasty in de novo native vessels, have been reported. In CAVEAT any coronary artery segment that could be by either technique was included; in CCAT only nonostial proximal left anterior descending coronary artery stenoses were studied.Methods. The primary end point was 6-month angiographic restenosis. Clinical outcome end points at 6 months included death, myocardial infarction, emergency bypass surgery and abrupt closure.Results. Initial angiographic success rates were significantly improved with directional coronary atherectomy compared with conventional angioplasty (89% vs. 80% for CAVEAT; 98% vs. 91% for CCAT). Also, the initial improvement in minimal lumen diameter and final immediate postprocedural residual diameter stenosis were better with atherectomy. In CCAT, there was no difference in initial complications; in CAVEAT, non-Q wave myocardial infarction rates and abrupt closure were increased with atherectomy. Despite improved success rates and better lumen achieved with atherectomy, in CCAT there was no difference in angiographic restenosis (46% for directional atherectomy vs. 43% for angioplasty). In CAVEAT, in a prespecified subset analysis involving the proximal left anterior descending coronary artery, restenosis was both significantly and clinically less for directional atherectomy (51% vs. 63%). For non-left anterior descending coronary artery segments, there was no difference.Conclusions. These studies document the difference between achievement of an excellent initial angiographic result and the longer term issue of clinical restenosis. Widespread use of directional coronary atherectomy to treat lesions that would be well treated by angioplasty in an attempt to decrease restenosis rates substantially does not appear indicated by the data. In individual lesions, directional atherectomy should be selected with the view toward optimizing initial results. Further trials are needed to determine whether more aggressive or better targeted directional coronary atherectomy may improve not only the initial gain but the long-term outcome as well.     

Mechanisms of balloon angioplasty and directional coronary atherectomy as assessed by intracoronary ultrasound.

OBJECTIVE. This study was designed to use intracoronary ultrasound imaging to elucidate the physical effects of balloon angioplasty and directional coronary atherectomy in vivo in humans. BACKGROUND. The proposed mechanisms of coronary artery interventions such as balloon angioplasty and directional atherectomy are based on animal studies or pathologic findings and these data may not be applicable to living patients. Intracoronary ultrasound findings correlate highly with pathologic results and may allow in vivo assessment of the mechanisms of such interventions in humans. METHODS. Intracoronary ultrasound imaging was performed in 45 patients after a successful coronary intervention (balloon angioplasty in 30, directional coronary atherectomy in 15). Ultrasound images obtained at the treatment site and at an adjacent angiographically normal references site were analyzed quantitatively for minimal lumen diameter, cross-sectional lumen area, are enclosed by the internal elastic lamina, plaque area (internal elastic lamina area--lumen area) and percent area stenosis (plaque area/internal elastic lamina area). Qualitative analysis included assessment of presence of dissection, plaque composition and plaque topography. RESULTS. The results of the two procedures were similar with respect to minimal lumen diameter (angioplasty 2.6 +/- 0.5 vs. atherectomy 2.6 +/- 0.3 mm, p = NS), lumen area (0.07 +/- 0.03 vs. 0.07 +/- 0.02 cm2, p = NS) and percent area stenosis (59 +/- 14% vs. 51 +/- 21%, p = NS). However, after angioplasty, the internal elastic lamina area was significantly larger at the treated site than at the reference site (delta = +0.03 +/- 0.04 cm2, p = 0.01). There was no significant difference between the two sites after atherectomy (delta = -0.01 +/- 0.05 cm2, p = NS). In addition, dissection was seen significantly more often after balloon angioplasty than after atherectomy (50% vs. 7%, p less than 0.01). The results were similar when stratified for plaque composition and morphology. These data were confirmed in six additional patients who underwent ultrasound imaging before and after the intervention. CONCLUSIONS. Thus, the improvement in lumen dimensions after coronary balloon angioplasty is a result of both vessel stretch, demonstrated by a larger internal elastic lamina area at the treated site, and dissection. Both vessel stretch and dissection are uncommon after atherectomy, a finding consistent with plaque removal as the major mechanism for improved lumen area after this procedure.     

The importance of acute luminal diameter in determining restenosis after coronary atherectomy or stenting.

BACKGROUND. We evaluated native coronary arteries treated by directional coronary atherectomy or balloon-expandable stent placement in an effort to derive a quantitative geometric model relating the luminal diameter immediately after intervention to that present 6 months later. The minimal luminal diameter of each lesion was measured before and immediately after intervention in 102 single Palmaz-Schatz stents and 134 directional atherectomies, 192 (81%) of which had repeat angiographic measurement of minimal luminal diameter 6 months after the intervention. The immediate enlargement in luminal diameter produced by the intervention (acute gain) and the subsequent reduction in luminal diameter from the time of intervention to 6 months of follow-up (late loss) were calculated. METHODS AND RESULTS. Luminal diameter increased from 0.69 +/- 0.40 mm to 3.11 +/- 0.64 mm (acute gain, 2.41 +/- 0.64 mm) after intervention, providing an immediate postprocedure residual stenosis of 1 +/- 14% relative to a reference diameter of 3.13 +/- 0.65 mm. At 6-month follow-up, the late luminal diameter was 1.97 +/- 0.92 mm (late loss, 1.13 +/- 0.89 mm), yielding a late diameter stenosis of 36 +/- 26%. The restenosis rate (according to the traditional definition of diameter stenosis > or = 50%) was 30%. Multivariable analysis demonstrated that late luminal diameter (p = 0.02), late percent stenosis (p = 0.04), and restenosis (according to a > 50% definition, p = 0.04) were each strongly associated with the luminal diameter present immediately after the procedure. Whereas late luminal diameter was also influenced by reference artery size and the vessel treated (left anterior descending versus right coronary artery), reference vessel size was rejected by the multivariable models of late percent stenosis and binary restenosis after they were adjusted for the effect of postprocedure luminal diameter. Once adjusted for postprocedure luminal diameter, neither late luminal diameter nor late loss was found to be independently determined by which device was used (atherectomy versus stents). Rather, late loss was determined independently by the immediate postprocedure luminal diameter (p = 0.005) and the postprocedure percent stenosis (p = 0.02). Although late loss thus increased with acute gain, the net beneficial effect of increased acute gain was maintained: Late loss was only a fraction (0.47) of acute gain, so the ability of a larger postprocedure luminal diameter to reduce the probability of subsequent restenosis was preserved. CONCLUSIONS. This quantitative model demonstrates that the late coronary lumen diameter and the probability of restenosis after Palmaz-Schatz stenting or directional atherectomy are influenced strongly by the lumen diameter present immediately after the procedure rather than by the specific device used. Although the influence of a larger acute result on reduced restenosis appears to be well established in this treatment population, the interplay among the multiple other biological influences on restenosis limits the ability to predict the probability of restenosis for the individual patient based on a large acute result alone. Future studies of restenosis, however, can further refine this multivariable quantitative model by adjusting for the effects of other clinical variables, mechanical interventions, or drug therapies in addition to the clear effect of postprocedure luminal diameter.     

Directional coronary atherectomy vs. rotational atherectomy for the treatment of in-stent restenosis of native coronary arteries.

Management of in-stent restenosis has become a significant challenge in interventional cardiology. Since the mechanism of in-stent restenosis is predominantly intimal hyperplasia, debulking techniques have been used to treat this condition. This study is a nonrandomized comparison of the immediate and long-term results of directional coronary atherectomy (DCA; n = 58) vs. high-speed rotational atherectomy (ROTA; n = 61) for the treatment of in-stent restenosis of native coronary arteries. There were no in-hospital deaths, Q-wave myocardial infarctions, or emergency coronary artery bypass surgery in either group. DCA resulted in a larger postprocedural minimal luminal diameter of (2.57 +/- 0.51 vs. 2.14 +/- 0.37 mm; P < 0.0001) and a larger acute gain (1.83 +/- 0.52 vs. 1.42 +/- 0.48 mm; P < 0.0001). Furthermore, 12-month clinically indicated target lesion revascularization (39% vs. 21%; P = 0.02) and long-term follow-up MACE (44% vs. 28%; P = 0.03) was greater in the ROTA group. The present study suggests that DCA appears to be superior to ROTA for the treatment of in-stent restenosis of native coronary arteries. Compared to ROTA, the debulking effect of DCA leads to a larger postprocedure minimal luminal diameter, and a lower incidence of subsequent target lesion revascularization and MACE.     

Novel approach to the analysis of restenosis after the use of three new coronary devices.

Restenosis after coronary intervention has remained a vexing problem despite the introduction of nearly 24 newer coronary interventional devices. To more clearly evaluate the potential impact of three such new devices on restenosis, coronary lumen diameters were measured before, immediately after and at 6 months after intervention, and restenosis was analyzed using continuous geometric techniques. Lumen diameters were measured before and immediately after intervention in 223 coronary vessels treated with one of three new devices: a single Palmaz-Schatz stent (n = 87), directional atherectomy (n = 125) and laser balloon angioplasty (n = 11); 184 (83%) of the patients underwent follow-up angiography 6 months after treatment. The immediate increase in lumen diameter produced by the intervention (acute gain) and the subsequent reduction in lumen diameter between the time of intervention to 6 month follow-up study (late loss) were examined. For each of the three interventions, the restenosis rate at follow-up study was analyzed using a traditional dichotomous definition (greater than or equal to 50% diameter stenosis), as well as a novel graphic technique. Although the apparent restenosis rates differed significantly among the three interventions (19% for stents, 31% for atherectomy and 50% for laser balloon angioplasty; p = 0.02), late loss among the three interventions was equivalent (average 1 mm; p = 0.91). There were, however, marked differences in the acute gain achieved by the three interventions: 2.6 mm for stents, 2.2 mm for atherectomy and 2 mm for laser balloon angioplasty; p less than 0.001). It was these differences in acute gain rather than late loss that explained the observed differences in restenosis rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative Coronary Dimensions and Restenosis After Directional Atherectomy or Balloon Angioplasty

Coronary artery dimensions were evaluated in 42 patients (52 lesions) undergoing directional atherectomy of primary atheromatous lesions in native coronary arteries between October 1989 and April 1991, Dimensions were compared with a cohort of 162 patients (213 lesions) undergoing percutaneous transluminal coronary angioplasty of similar lesions between March 1984 and April 1988. Computer-assisted quantitative angiography was performed for paired near-orthogonal views (captured during diastole) of each treated lesion; image pairs taken prior to, immediately following, and 6 months after coronary intervention were studied. Although coronary dimensions were equivalent for the two treatment groups before therapy, the immediate posttreatment minimal lumen diameter was significantly larger after atherectomy than angioplasty (2.24 ± 0.53 mm vs 1.52 ± 0.34 mm, P < 0.01). Despite this, coronary dimensions were similar in the two groups at follow-up angiography. Several dichotomous definitions of restenosis were tested using these quantitative data. Restenosis rates were similar for the two treatments using most definitions, but those definitions based on loss of relative or absolute lumen dimensions resulted in higher rates of restenosis following atherectomy. These data demonstrate that: (1) directional coronary atherectomy can achieve greater initial gain in luminal dimensions than angioplasty; (2) the loss in vessel dimensions within 6 months (late loss) is greater after atherectomy than after angioplasty; and (3) restenosis definitions rely on relative or absolute loss of initial luminal gain favor of angioplasty. (J Interven Cardiol 1996;9:121–127)     

Quantitative Angiography of Coronary Artery Dimensions 24 Hours After Rotational Atherectomy

Rotational atherectomy results in platelet activation and heat generation, which may impact artery size immediately after treatment. In addition, arteries treated with balloon angioplasty may exhibit recoil within 24 hours. In this study, arteries treated with rotational atherectomy, with and without adjunctive balloon angioplasty, were analyzed by quantitative coronary angiography to determine the effect of rotational atherectomy on the dynamic behavior of the arterial wall within 24 hours after the procedure. Quantitative coronary angiography was performed at a core laboratory. Coronary angiogram acquisitions were preceded by intracoronary nitroglycerin injections and were repeated using identical angles of projection. Proximal and distal reference vessel diameters were 2.55 ± 0.60 and 2.28 ± 0.51 mm, respectively, and did not change from pre- to postprocedure. Both were larger the following day increasing to 2.72 ± 0.65 and 2.52 ± 0.52 mm, respectively, (p <0.001). Minimum luminal diameter (MLD) increased from 0.70 ± 0.28 mm before to 1.49 ± 0.34 mm after the procedure and to 1.72 ± 0.37 mm at 24-hour follow-up (p <0.001). Subset analysis of patients treated with rotational atherectomy alone or rotational atherectomy with adjunctive balloon angioplasty revealed that the increase in luminal diameters occurred in both subsets. Patients treated with adjunctive angioplasty had a smaller initial MLD, a larger postprocedure MLD, and no difference in MLD at 24-hour follow-up compared with stand-alone rotational atherectomy. Subset analysis of 100 patients who had 6-month follow-up angiography revealed that both a calculated acute gain and chronic late loss, based on a 24-hour film, differed significantly from values using a film acquired immediately after the procedure. However, the slope of the linear regression between acute gain and chronic late loss did not differ. Coronary arteries treated with rotational atherectomy with or without adjunctive balloon angioplasty increase significantly in size during the first 24 hours after the procedure. This phenomenon has implications for the calculation of absolute gain and chronic late loss, but not for the linear relation between the 2 quantitative outcomes.     

Optimal use of directional coronary atherectomy is required to ensure long-term angiographic benefit: A study with matched procedural outcome after atherectomy and angioplasty

Objectives. This study was designed to examine whether restenosis is related to the extent or mechanism of lumen improvement and to explore angiographic determinants of optimal atherectomy.Background. Directional atherectomy induces a greater extent of immediate gain and late loss but has not been found to yield a better late angiographic lumen than angioplasty in randomized trials. The difference in lumen renarrowing may be related to either the extent or the mechanism of immediate gain. The design of previous studies has precluded the detection of a device-specific effect on restenosis.Methods. A retrospective analysis was based on matching a prospectively collected series of 80 native coronary arteries successfully treated with atherectomy with a prospectively collected series of 80 native coronary arteries successfully treated with balloon angioplasty. Angiographic analysis was performed in 160 lesions to explore whether a specific device-related effect exists. Multivariate analyses were performed to determine the correlates of minimal lumen diameter at follow-up and late lumen loss and to identify the procedural characteristics for optimal atherectomy.Results. Matching resulted in two comparable groups with equivalent baseline clinical and stenosis characteristics. By study design, atherectomy and angioplasty resulted in similar mean (±SD) immediate lumen gain (1.15 ± 0.44 vs. 1.10 ± 0.40 mm, p = 0.50). However, lumen loss was more pronounced after atherectomy, and, thus, the minimal lumen diameter at follow-up differed significantly between the two groups (1.78 ± 0.57 vs. 2.00 ± 0.56 mm, p = 0.001). Device type was retained in the multivariate analysis as an independent predictor of late minimal lumen diameter and lumen loss. Multivariate analysis identified vessel size and immediate gain as determinants of optimal atherectomy.Conclusions. Restenosis is a consequence not only of the extent of lumen improvement but also of the mechanism of vessel wall injury (debulking vs. dilating). While performing atherectomy, the operator should strive for an optimal procedural result to accommodate an increased intimal hyperplastic response.     

Role of new devices for angioplasty in the unprotected left main coronary artery]

OBJECTIVES: Angioplasty for the unprotected left main trunk remains controversial, but new procedures and devices such as directional coronary atherectomy and stenting have improved the results. We compared the results of angioplasty with the inflexible balloon and new devices. METHODS: The procedures were performed in 239 consecutive lesions in 160 patients between April 1986 and March 2000. This study excluded emergency cases and repeat angioplasty cases, and included 120 initial and elective cases. Initial and long-term results were compared between the balloon group (n = 29) and the new device group (n = 91). RESULTS: Lesion success rate was lower in the balloon group (90% vs 100%, p < 0.05), but there were no significant differences in in-hospital results including cardiac death (0% vs 0%), noncardiac death (0% vs 3.3%), Q-wave myocardial infarction (0% vs 2.2%), non-Q wave myocardial infarction (3.4% vs 6.6%), bypass surgery (0% vs 0%) and repeat angioplasty (6.9% vs 1.1%). Quantitative angiography showed significant improvements in minimal lumen diameter (mean 2.17 vs 3.16 mm, p < 0.001) and percentage diameter stenosis (mean 31% vs 13%, p < 0.001) in the new device group after the procedures. The minimum lumen diameter remained larger at 3 (p < 0.001) and 6 months (p < 0.05) in the new device group. Therefore, angiographic restenosis rate was higher in the balloon group (55% vs 21%, p < 0.005). Five-year survival rate showed no significant difference between the groups (75.0% vs 83.8%). CONCLUSIONS: New devices significantly improved the minimal lumen diameter after angioplasty for unprotected left main trunk disease, and lead to significant improvement of restenosis rate at follow-up.     

Influence of stenotic lesion morphology on immediate and long-term (6 months) angiographic outcome: Comparative analysis of directional coronary atherectomy versus standard balloon angioplasty

Objectives. This study sought to determine whether preprocedural lesion morphology differentially affects the outcome of directional coronary atherectomy versus standard balloon angioplasty.Background. Despite previous studies (Canadian Coronary Atherectomy Trial [CCAT]/Coronary Angioplasty Versus Excisional Atherectomy Trial [CAVEAT]), directional coronary atherectomy continues to be recommended on the basis of lesion-specific features, although the validity of this approach has never been proved.Methods. A retrospective, subgroup analysis of the CCAT data base (group average ± SD) was performed.Results. In the long term (6 months), both procedures were equally successful in the proximal left anterior descending coronary artery (directional atherectomy 0.62 ± 0.70 mm vs. coronary angioplasty 0.70 ± 0.72 mm, p = NS), with atherectomy tending to perform best in relatively “simple” lesions (American College of Cardiology/American Heart Association [ACC/AHA] type A: atherectomy 0.57 ± 0.70 mm vs. angioplasty 0.50 ± 0.77 mm; ACC/AHA type B₁: atherectomy 0.65 ± 0.68 mm vs. angioplasty 0.60 ± 0.68 mm) and those with moderate dystrophic calcification (atherectomy 0.79 ± 0.56 mm vs. angioplasty 0.45 ± 0.73 mm). Although greatest minimal lumen diameter gains were seen in larger (>3 mm) coronary arteries (atherectomy 0.76 ± 0.62 mm vs. angioplasty 0.80 ± 0.72 mm, p = NS) and those with severe obstruction (preprocedural minimal lumen diameter < 1.0 mm: atherectomy 0.80 ± 0.62 mm vs. angioplasty 0.84 ± 0.63 mm, p = NS), neither technique was superior, and eccentric stenoses (symmetry index < 0.5) had similar outcomes (atherectomy 0.59 ± 0.49 mm vs. angioplasty 0.62 ± 0.65 mm, p = NS).Conclusions. These data refute many preconceptions regarding the choice of directional coronary atherectomy on the basis of anatomic criteria.     

Directional coronary atherectomy for lesions of the proximal left anterior descending artery: initial clinical results, complications and histopathological findings

Background: Directional coronary atherectomy is a percutaneous technique which extends the role of balloon angioplasty to bulky eccentric coronary lesions. Aims: To report the early experience, clinical results, complications and histopathological findings of directional coronary atherectomy (DCA) in proximal left anterior descending artery (LAD) stenosis. Methods: Study of 25 lesions in 24 patients on whom directional atherectomy was performed on the proximal LAD artery with the Simpson coronary atherectomy device. Results: Twenty-five procedures were performed on 24 patients with stenosis in the proximal LAD artery. There were 21 males and three females with a mean age of 56.5 years. Sixteen patients presented with stable angina and eight with unstable angina. Eight patients had previous myocardial infarction (MI). Angiographic success was obtained in 24 of 25 lesions (96%). The mean lesion length was 13.1 ± 3.7 mm and the mean LAD artery diameter was 3.6 ± 0.5 mm. Minimal luminal diameter improved from 0.9 ± 0.4 mm to 3.0 ± 0.5 mm and the percentage diameter stenosis reduced from 75 ± 12% to 16 ± 9%. Complications included acute occlusion in one patient, non-Q MI in three patients, local vascular complications in one patient and side-branch loss in one patient. Histology demonstrated fibrous cap of atherosclerotic plaque in 100%, media and internal elastic lamina in 28% and intimal hyperplasia in 100% of restenotic lesions and 27% of native lesions. Restenosis rates in angiographically restudied patients was 27%. The mean minimal luminal diameter at follow-up was 2.3 ± 0.9 mm and the mean percentage diameter stenosis was 35 ±21%. Conclusion: From this initial study, we conclude that DCA is an effective and safe procedure for the treatment of large proximal LAD lesions. DCA provides a large luminal diameter and a ‘smoother’ angiographic appearance compared to coronary angioplasty. Acute complication rates are low and restenosis rates were comparable with percutaneous transluminal coronary balloon angioplasty.     

Six-month Follow-up of Successful Stenting for Acute Dissection After Coronary Angioplasty: Comparison Between Slotted Tube (Palmaz-Schatz) and Flexible Coil (Gianturco-Roubin) Stent Designs

The aim of this study was to evaluate the influence that two different stent designs may have in late outcome following successful coronary stent implantation for acute dissection after balloon angioplasty. In the present study, 50 consecutive patients were matched to compare late outcome between the use of slotted tube (Palmaz-Schatz) and flexible coil (Gianturco-Roubin) stent designs (25 in each group). Group matching was performed according to vessel size, location of target lesion, and dissection type among patients undergoing successful coronary stenting to treat an acute dissection following balloon coronary angioplasty. Poststent minimal luminal diameter (2.46 ± 0.49 mm vs 2.35 ± 0.47 mm, not significant [NS]) and acute luminal gain (2.02 ± 0.61 mm vs 1.85 ± 0.56 mm, NS) were similar in slotted tube and flexible coil stent groups, respectively. However, at 6-month follow-up, late loss in luminal diameter was larger in lesions treated with a flexible coil stent (0.96 ± 0.75 mm vs 0.62 ± 0.55 mm, P = 0.05), and minimal luminal diameter was smaller in those lesions treated with a flexible coil stent (1.38 ± 0.87 mm vs 1.84 ± 0.63 mm, P < 0.05). Angiographic restenosis (> 50% diameter narrowing) occured in four lesions treated with a slotted tube stent (16%) compared to ten lesions treated with a flexible coil stent (40%, P < 0.05). The design of the coronary stent may have significant influence in the late lesion outcome. In patients with acute dissection following balloon coronary angioplasty, use of a slotted tube stent design (Palmaz-Schatz) may result in lower late loss and larger luminal diameter at 6-month follow-up than use of a flexible coil stent design (Gianturco-Roubin).     

Chlamydia pneumoniae seropositivity predicts the risk of restenosis after percutaneous transluminal coronary angioplasty

This study was done to evaluate whether anti-Chlamydia pneumoniae seropositivity can be a predictor of restenosis after coronary intervention. Recent studies indicate that latent infection with C. pneumoniae is associated with and could possibly cause atherosclerosis. However, it is unknown whether chronic infection with this microorganism is involved in the mechanism of restenosis after percutaneous transluminal coronary angioplasty. We prospectively studied 78 consecutive patients (90 target lesions) with symptomatic coronary artery disease who underwent successful coronary intervention to a de novo lesion (conventional balloon angioplasty to 31 lesions and stent implantation to 59 lesions). At angioplasty, blood samples were collected to measure the serum level of anti-C. pneumoniae IgG to examine whether seropositive patients were prone to restenosis and whether the seropositivity could predict the risk of restenosis determined by follow-up coronary angiography performed within 6 months after the angioplasty. Restenosis, defined as more than 50% stenosis with an increase of 15% or more in the degree of stenosis from that measured on cineangiograms after angioplasty, developed in 36 of 62 seropositive patients and in 4 of 16 seronegative patients (58% vs 25%, P = 0.025). Lesions in the seropositive patients had a greater mean loss index (mean ± SD 0.75 ± 0.45 vs 0.35 ± 0.41, P < 0.001), which was defined as late loss (luminal diameter reduction at follow-up angiography) divided by acute gain (luminal diameter gain by angioplasty), in late loss (1.07 ± 0.64 mm vs 0.65 ± 0.79 mm, P = 0.019), in percentage of diameter stenosis (57% ± 20% vs 41% ± 21%, P = 0.003) and a lesser mean in minimal luminal diameter (1.18 ± 0.58 mm vs 1.67 ± 0.63 mm, P = 0.002) at follow-up angiography. In a multivariate logistic regression model, anti-C. pneumoniae IgG seropositivity was a strong independent predictor of restenosis compared to the other risk factors (odds ratio = 6.2, P = 0.01). C. pneumoniae could play an important role in the mechanism of restenosis and evaluation of the IgG seropositivity, and may help to identify patients at high risk for restenosis. Received: June 13, 2001 / Accepted: December 7, 2001     

One hundred and thirteen attempts at directional coronary atherectomy: the early and combined experience of two European centres using quantitative angiography to assess their results.

Directional coronary atherectomy has been introduced as an alternative to conventional balloon angioplasty when treating coronary artery stenoses with complex lesion morphology. To determine the immediate efficacy of coronary atherectomy in patients with such lesions, the first 113 attempts at directional atherectomy in two centres using quantitative angiography were reviewed in 105 patients. The lesions were classified as complex stenosis since 95% had a symmetry index less than 1.0, a length of 6.83 +/- 2.55 mm on average and an area of plaque of 9.77 +/- 6.69 mm2. Procedural success defined as a residual stenosis less than or equal to 50% after tissue retrieval was obtained in 90 (85.7%) of 105 patients. The primary angioplastic success rate, combining atherectomy and balloon angioplasty in case of failed attempt of atherectomy was 95.2%. Coronary atherectomy was unsuccessful in five patients; three were referred for emergency coronary artery bypass grafting. Major complications (death, emergency surgery and transmural infarction) were encountered in 5.7% of the patients. Assessed by quantitative coronary analysis, a residual minimal luminal diameter of 2.42 +/- 0.52 mm and a diameter stenosis of 26 +/- 12% were obtained immediately after directional coronary atherectomy. We conclude that directional coronary atherectomy is particularly suitable for the treatment of stenosis with complex lesion morphology and is associated with acceptable complication rates. Randomized trials comparing atherectomy with balloon angioplasty are warranted to clarify the role of atherectomy in the treatment of lesions in the proximal part of the three major epicardial coronary arteries.