Clinical, histologic and quantitative angiographic predictors of restenosis after directional coronary atherectomy: a multivariate analysis of the renarrowing process and late outcome

Invasive testing for coronary artery disease: FFR, IVUS, OCT, NIRS

Coronary angiography is the gold standard for the diagnosis of coronary artery disease and guides revascularization strategies. The emergence of new diagnostic modalities has provided clinicians with adjunctive physiologic and image-based data to help formulate treatment strategies. Fractional flow reserve can predict whether percutaneous intervention will benefit a patient. Intravascular ultrasonography and optical coherence tomography are intracoronary imaging modalities that facilitate the anatomic visualization of the vessel lumen and characterize plaques. Near-infrared spectroscopy can characterize plaque composition and potentially provide valuable prognostic information. This article reviews the indications, basic technology, and supporting clinical studies for these modalities.

Relation of coronary artery size to one-year clinical events after new device angioplasty of native coronary arteries (a New Approach to Coronary Intervention [NACI] Registry Report)

The influence of vessel size on clinical and angiographic outcomes after new device angioplasty has not been well documented. We reviewed clinical and angiographic outcomes of 2,044 patients undergoing new device angioplasty of native vessels enrolled in the New Approaches to Coronary Interventions (NACI) Registry. Quantitative angiography was performed using standard methods. Patients were divided into 3 groups according to reference vessel diameter (RVD) (<2.75, 2.75 to 3.25, and >3.25 mm). Patients with the smallest vessels had a higher incidence of diabetes (26% vs. 16%, p<0.01), multivessel disease (50% vs. 45%, p<0.01), left anterior descending coronary artery disease (61% vs. 39% p<0.01), and in general, more severe baseline lesion characteristics than patients with larger (>3.25 mm) vessels. Absolute baseline and final minimal lumen diameter (MLD) was also smaller in patients with RVD <2.75 mm despite similar final percent diameter stenosis. Although in-hospital events were similar, patients who underwent interventions in vessels <2.75 mm had an increased incidence of death (p<0.01), surgical revascularization (p<0.05), and target lesion revascularization (TLR) (p<0.01) at 1 year. Multivariate analysis by vessel size showed a stepwise increase in the risk of TLR by 1 year in patients with the smaller RVD (p = 0.0001) and the combined end point of 1 year death/Q wave-myocardial infarction/TLR (p = 0.02). Thus, despite similar early clinical events among patients undergoing new device angioplasty, patients who underwent treatment of smaller vessels had a significantly increased risk of major adverse clinical events and particularly TLR by 1 year after new device angioplasty of native coronary arteries.

Clinical and angiographic outcome of stenting following suboptimal results of percutaneous transluminal coronary angioplasty in small (<2.5 mm) coronary arteries

The purpose of the present study was to evaluate the feasibility and efficacy of stenting following suboptimal percutaneous transluminal coronary angioplasty (PTCA) in angiographically small coronary arteries. The clinical and angiographic outcome of unplanned stenting in 33 patients with coronary arteries <2.5 mm in diameter was studied. Procedural success was achieved for 97.0% with a greater initial gain (1.79 +/- 0.60 vs. 1.34 +/- 0.58 mm, P < 0.05) and larger postprocedural minimal luminal diameter (2.19 +/- 0.43 vs. 1.57 +/- 0.57 mm, P < 0.001) than that in the size-matched elective PTCA patients. Trends toward a lower restenosis rate and a significant reduction in target lesion revascularization (7.1% vs. 41.9%, P < 0.01) were observed in the stented patients, suggesting the feasibility and efficacy of stenting following suboptimal PTCA in small coronary arteries. Cathet. Cardiovasc. Intervent. 47:269-276, 1999.

Low restenosis rate in lesions of the left anterior descending coronary artery with stenting following directional coronary atherectomy

The present study evaluated acute and late results with stenting following directional coronary atherectomy (DCA) for the lesions in the left anterior descending coronary artery (LAD). Between April 1995 and January 1997, 200 LAD lesions with > or =3 mm reference vessel diameter were treated with coronary stents. The lesions were divided as to whether or not DCA was performed before stenting; 1) stenting alone (n = 163) and 2) debulking and stenting (n = 37). There were no significant differences in the incidences of complications except for non-Q-wave myocardial infarction that was more frequent in patients with debulking and stenting than in those with stenting alone (13.5% vs. 2.4%, P < 0.05). A greater acute lumen gain (2.85 +/- 0.66 vs. 2.25+/-0.60 mm, P < 0.01) and minimal lumen diameter (3.64+/-0.56 vs. 3.15+/-0.41 mm, P < 0.01) after stenting were observed in patients with debulking and stenting than in those with stenting alone. At follow-up patients with debulking and stenting continued to have a greater minimal lumen diameter (2.88+/-0.72 vs. 2.15+/-0.85 mm, P < 0.01) and had a lower restenosis rate (6.3% vs. 23.1%, P < 0.05) than those with stenting alone. Stenting following DCA appears to be advantageous in the LAD lesions with > or =3 mm reference vessel diameter.

Effectiveness of tranilast on restenosis after directional coronary atherectomy

Tranilast is an antiallergic drug used widely in Japan that also inhibits the migration and proliferation of vascular smooth muscle cells. This pilot study was undertaken to determine the effectiveness of tranilast on restenosis after successful directional coronary atherectomy. After the procedure, 40 patients (56 lesions, tranilast group) were treated with oral tranilast for 3 months, and 152 patients (188 lesions, control group) did not receive tranilast. Angiographic and clinical variables were compared between the two groups. The minimal lumen diameter was significantly larger in the tranilast group than in the control group at both 3-month (2.08 vs 1.75 mm, p = 0.004) and 6-month follow-up (2.04 vs 1.70 mm, p = 0.003). The diameter stenosis in the tranilast group was smaller than that in the control group both 3 months (28% vs 40%, p = 0.0007) and 6 months (30% vs 43%, p = 0.0001) after the procedure, with a lower restenosis rate (percent diameter stenosis > or =50) in the tranilast group at 3 months (11 % vs 26%, p = 0.03). The number of clinical events over the 12-month period after the procedure was significantly reduced by tranilast administration (p = 0.013). These findings suggest that the oral administration of tranilast strongly prevents restenosis after directional coronary atherectomy.

Coronary AVE micro stents: serial quantitative angiography and histology in a canine model

The AVE Micro Stent (AVE Inc., Santa Rosa, CA) is composed of helically welded 3 mm long, zigzag crowns with stent lengths from 6 to 39 mm and diameters from 2.5 to 4.5 mm. Quantitative coronary angiography and histologic analyses of acute and chronic implantation were obtained in 52 stented coronary segments of 18 dogs. Three hearts with 8 stented coronary segments were harvested after 24 hr, 3 hearts with 9 stented segments were harvested after 2 weeks, 6 hearts with 15 stented segments were harvested at 8 weeks, and 6 hearts with 20 stented segments were harvested at 24 weeks post-deployment. There were no procedural complications, deaths, or acute vessel closures. The average lumen diameter of the stented segment was largest at 2 weeks (3.3 +/- 0.3 mm). The smallest average diameters were observed at 8 weeks after the stent deployment (2.7 +/- 0.4, P < 0.05) with an increase again at 24 weeks (2.9 +/- 0.6). The pre-explant percent of stenosis was <30% in all animals. Histologically, a peak of inflammation was visible at 2 weeks; however, the extent of luminal narrowing reached its peak at 8 weeks and the lumen dimension increased somewhat at 24 weeks. The degree of intimal thickening remained relatively constant throughout the different time points (<200 microm). Overall, these data suggest that constrictive remodeling within the stented segment occurs at 8 weeks in this animal model. The later increase of the stented segment dimensions as well as higher net gain at 24 weeks compared to 8 weeks after deployment suggests that this constriction is a transitory phenomenon.

Impact of restenosis after optimal directional coronary atherectomy on regional left ventricular function

To assess the effect of optimal directional coronary atherectomy (DCA) on restenosis and left ventricular (LV) function, 95 patients who underwent DCA and adjunctive balloon angioplasty for de novo lesions were prospectively followed for 6 months. Absolute and relative coronary lumen measurements were analyzed with online quantitative coronary angiography. LV volumes, ejection fraction, and segmental wall motion were measured off-line according to the radial method for LV cineangiograms acquired in a right anterior oblique projection. Target vessels were the left anterior descending artery in 63 patients and right coronary artery in 32. Mean (+/- SD) reference diameter was 3.58 +/- 0.65 mm. Mean lumen diameter improved significantly after DCA from 1.19 +/- 0.44 to 3.03 +/- 0.45 mm, yielding a 14 +/- 10% residual stenosis. Overall angiographic restenosis rate (> 50% stenosis in diameter) at control was 23%. In patients without restenosis, there were no significant changes in LV volumes or in LV pressures. In this subgroup, ejection fraction improved significantly in the left anterior descending group (mean difference 3 +/- 10%, p < 0.04). Moreover, there was an increase in fractional shortening of all anterior segments (mean difference 11 +/- 16%, p < 0.005). Improvement in fractional shortening was less marked in the right coronary artery group even without restenosis. We conclude that: (1) optimal DCA can achieve a low restenosis rate in selected large vessels, (2) long-term beneficial effects on regional LV function are possible, particularly in patients with left anterior descending disease and in the absence of coronary restenosis.

Comparison of balloon angioplasty and Simpson atherectomy for lesions in the femoropopliteal artery: angiographic and clinical results of a prospective randomized trial

PURPOSE

This study involves a prospective randomized trial comparing clinical and angiographic results of balloon angioplasty (BA) and Simpson directional atherectomy (DA) in patients with short lesions in the femoropopliteal artery causing symptoms of intermittent claudication.

MATERIALS AND METHODS

Thirty-five patients were treated with BA and 38 with DA. Procedural complications were seen in eight patients. Residual stenoses immediately after the procedure with between 30% and 50% diameter reduction (DR) were observed in three patients after BA and in five patients after DA. In all other patients, residual stenosis was less than 30% DR. Two study end-points during a 2-year follow-up were used: the angiographic occurrence of restenosis with a DR of 50% or greater or the recurrence of symptoms.

RESULTS

Clinical success after 2 years, according to the criteria of the Society for Vascular Surgery/International Society for Cardiovascular Surgery, was seen in 79% of the BA patients and 56% of the DA patients (P = .07). The 2-year primary angiographic patency rates were 67% in patients treated with BA and 44% in patients treated with DA (P = .06). The secondary angiographically determined patency rates were 80% and 65%, respectively (P = .15).

CONCLUSION

Simpson atherectomy is an interventional technique to treat arterial lesions in the femoropopliteal artery with an acceptably low complication rate. The clinical and angiographic results of DA and BA are comparable. DA should not be used to replace BA for routine treatment of short femoropopliteal lesions.

Effect of subintimal resection on initial outcome and restenosis for native coronary lesions and saphenous vein graft disease treated by directional coronary atherectomy. A report from the CAVEAT I and II investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial

OBJECTIVES

This study was designed to determine whether the depth of tissue resection affected either immediate outcome or subsequent restenosis in patients treated by directional coronary atherectomy (DCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I and II studies.

BACKGROUND

The relation between the depth of tissue resection, immediate outcome and subsequent restenosis in lesions treated with DCA has been controversial.

METHODS

In CAVEAT I, 412 patients undergoing DCA had tissue samples available for analysis by the core laboratory, whereas in CAVEAT II, 113 patients had vein graft tissue specimens available.

RESULTS

Subintimal deep arterial wall resection was demonstrated in 169 patients (41%) in CAVEAT I and 40 (35%) in CAVEAT II. The depth of tissue resection did not affect initial procedural outcome in either CAVEAT I or CAVEAT II, nor did it affect subsequent restenosis rates at 6 months in native coronary lesions (CAVEAT I, 50.8% for intimal resection vs. 51.2% for subintimal resection). In patients treated with vein graft disease (CAVEAT II), restenosis rates varied; when resection was limited to the intima, a restenosis rate of 40.4% was documented, whereas in patients with subintimal resection, the restenosis rate was 57.1%. This difference was not statistically significant (p = 0.144).

CONCLUSIONS

This combined randomized series of DCA for treatment of primary native coronary artery and vein graft stenoses with quantitative coronary angiography and core laboratory pathologic assessment resolves the controversy created by previous experimental and clinical data regarding deep vessel wall resection and immediate and longer outcome. Directional atherectomy with deep arterial wall resection as practiced in these studies is safe and does not jeopardize initial success rates. More important, deep wall resection is not associated with significantly increased restenosis rates.

Clinical and angiographic comparison of matched patients with successful directional coronary atherectomy or stent implantation for primary coronary artery lesions

OBJECTIVES

This study was designed to compare the long-term clinical and angiographic effects of successful directional atherectomy and stent implantation and to examine whether restenosis is related to the mechanism of lumen improvement as well as the extent of lumen gain.

BACKGROUND

Directional atherectomy and coronary stent implantation have been shown to achieve a more optimal immediate result that may lead to a more favorable long-term angiographic outcome and fewer target vessel revascularizations than does angioplasty. However, it remains to be determined whether one of the devices used in these interventions provides consistently better results than the other.

METHODS

To allow meaningful comparisons a prospectively collected series of 117 patients successfully treated with atherectomy were individually matched with a prospectively collected series of 117 patients successfully treated with stent implantation. Matching for baseline characteristics identified patients with identical lesion location and lesion severity, and immediate and late angiographic and clinical outcome were compared. To evaluate the possibility of a procedure effect on restenosis, patients were further matched for both immediate angiographic outcome and baseline characteristics, providing 150 matched patients for comparison. As confirmatory analysis, multivariate models were constructed to predict late lumen diameter.

RESULTS

Matching resulted in two comparable groups with equivalent baseline clinical and stenosis characteristics (n = 117 pairs). Atherectomy led to a smaller immediate gain than stenting and, because late loss was similar in both groups, stenting resulted in a larger late lumen (1.96 +/- 0.51 vs. 1.66 +/- 0.55 mm, p < 0.0001). When patients were matched for immediate gain and baseline characteristics (n = 75 pairs), lumen loss was more pronounced after atherectomy, and thus the minimal lumen diameter at follow-up differed significantly between the two groups (1.66 +/- 0.53 vs. 1.90 +/- 0.47 mm, p = 0.004). This beneficial angiographic effect of stenting was accompanied by a reduced need for repeat interventions. Multivariate analysis confirmed the independent effect of the interventional device used, whereby less loss and greater lumen diameter at follow-up were predicted for stent implantation than for atherectomy.

CONCLUSIONS

Successful stent implantation provided a more favorable long-term angiographic outcome and lower rates of restenosis and need for target lesion revascularization than did atherectomy. This favorable effect of stenting not only is related to a larger, immediate gain, but also seems to attenuate late lumen loss.

High-speed rotational atherectomy: six-month serial quantitative coronary angiographic follow-up

One hundred twenty-three patients treated with high-speed rotational atherectomy (HSRA) were restudied 6.9 +/- 1.2 months later. At the follow-up, the number of focal concentric lesions increased from 32.2 percent to 63.0 percent, p<0.01, with decrease of type C lesions from 54.8 percent to 30.8 percent, p<0.05. Comparison of the degree of the net gain (NG) showed more severe baseline lesions in the high-gain group (NG >20 percent) compared with the moderate-gain group (20 percent > NG > 0 percent) and to the loss group (minimal luminal diameter [MLD] 0.8 +/- 0.4 mm vs 1.0 +/ 0.4 mm, p<0.05; and 1.2 +/- 0.5 mm; p<0.01, respectively). Highest initial gain (36.5 percent +/- 26.2 percent vs 24.5 percent +/- 18.1 percent; p<0.015; and 19.0 percent +/- 23.2 percent; p<0.001) as well as lowest late loss (1.8 percent +/- 21.7 percent vs 14.0 percent +/-18.4 percent; p<0.01 and 28.1 percent +/- 25.0 percent; p<0.01) were found in the high NG group. A higher interaction between burr and atheroma resulted in the lowest restenosis rate of 6 percent.

Immediate and late outcome of excimer laser and balloon coronary angioplasty: a quantitative angiographic comparison based on matched lesions

OBJECTIVES

This study sought to compare acute lumen changes and late lumen narrowing during and after excimer laser-assisted balloon angioplasty, measured by quantitative coronary angiography, with the immediate and long-term outcome of balloon angioplasty alone.

BACKGROUND

Although excimer laser coronary angioplasty is used as an adjunct or alternative to balloon angioplasty, limited comparative data exist regarding the immediate and long-term efficacy of excimer laser-assisted balloon angioplasty versus balloon angioplasty alone.

METHODS

A series of 53 lesions in 47 consecutive patients successfully treated with excimer laser-assisted balloon angioplasty were individually matched after completion of 6-month follow-up angiography with 53 successfully treated balloon angioplasty lesions according to vessel location, preprocedural minimal lumen diameter and reference diameter. Immediate and long-term angiographic results were assessed by an automated lumen contour detection algorithm.

RESULTS

Before intervention in the laser and balloon angioplasty groups, respectively, minimal lumen diameter (mean +/- SD) was 0.73 +/- 0.47 and 0.74 +/- 0.46 mm, and reference diameter was 2.71 +/- 0.42 and 2.72 +/- 0.41 mm. Laser angioplasty was followed by adjunctive balloon dilation in 50 lesions. Mean balloon diameter at maximal inflation was similar in both treatment groups (2.61 +/- 0.32 and 2.65 +/- 0.38 mm, respectively), resulting in similar minimal lumen diameters after intervention of 1.77 +/- 0.41 and 1.78 +/- 0.34 mm, respectively. At follow-up angiography, minimal lumen diameter after excimer laser-assisted balloon angioplasty was 1.17 +/- 0.63 mm, and that after balloon angioplasty alone was 1.46 +/- 0.67 mm (p = 0.02). The angiographic restenosis rates at follow-up using the 50% diameter stenosis cutoff criterion were 57% and 34%, respectively (p = 0.02).

CONCLUSIONS

Quantitative angiographic analysis of a matched group of 106 successfully treated coronary lesions showed a similar immediate outcome but reduced long-term efficacy of excimer laser-assisted balloon angioplasty compared with that after balloon angioplasty alone.

Angiographic, ultrasonic, and angioscopic assessment of the coronary artery wall and lumen area configuration after directional atherectomy: the mechanism revisited

The purpose of the present study was to use the complementary information of angiography, intravascular ultrasound, and intracoronary angioscopy before and after directional atherectomy to characterize the postatherectomy appearance of vessel wall contours and the mechanism of lumen enlargement. Directional coronary atherectomy aims at debulking rather than dilating a coronary artery lesion. The selective removal of the plaque may potentially minimize the vessel wall damage and lead to subsequent better late outcome. Whether plaque removal is the main mechanism of action has only to be assessed indirectly by angiography and warrants further investigation with detailed analysis of luminal changes and vessel wall damage by ultrasound and direct visualization with angioscopy. Twenty-six patients have been investigated by quantitative angiography, intravascular ultrasound, and intracoronary angioscopy (n = 19) before and after atherectomy. In addition, all retrieved specimens were microscopically examined. Ultrasound imaging showed an increase in lumen area from 1.95 +/- 0.70 mm2 to 7.86 +/- 2.16 mm2 at atherectomy. The achieved gain mainly resulted from plaque removal because plaque plus media area decreased from 18.16 +/- 4.47 mm2 to 13.13 +/- 3.10 mm2. Vessel wall stretching (i.e., change in external elastic lamina area) accounted for only 15% of lumen area gain. Luminal gain was higher in noncalcified (6.52 +/- 2.12 mm2) lesions than in lesions containing deeply located calcium (5.19 +/- 0.99 mm2) and lowest in superficially calcified lesions (5.41 +/- 2.41 mm2). Ultrasound imaging identified an atherectomy byte in 85% of the cases, whereas angioscopy revealed such a crevice in 74%. The complementary use of the three techniques revealed an underestimation of the presence of dissection/tear and new thrombus by angiography (10% and 4%) and ultrasound imaging (12% and 0%) compared with angioscopy (26% and 21%). The combined use of angiography, ultrasound, and angioscopy reveals that the postatherectomy luminal lining is not as regular and smooth as that seen by angiography. Luminal enlargement with atherectomy is achieved by plaque excision rather than arterial expansion.

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.

Acute and long-term outcome of directional coronary atherectomy for stable and unstable angina

The clinical efficacy and safety of directional coronary atherectomy for the treatment of stable and unstable angina were assessed in 82 patients with stable and 68 patients with unstable angina. Therefore, clinical and angiographic follow-up was obtained in a prospectively collected consecutive series of 150 atherectomy procedures. Restenosis was assessed clinically and by quantitative angiography. The overall clinical success rate of atherectomy for patients with unstable and stable angina was 88% and 91%, respectively. No significant differences were found for in-hospital event rates between the unstable and stable angina groups: death (1.5% vs 0%), myocardial infarction (10% vs 6%), and emergency bypass operation (3% vs 2%). These clinical events were related to the occurrence of abrupt occlusions (8.8% in patients with stable and 6.1% in those with unstable angina; p = NS). Clinical follow-up was achieved in 100% of the patients with stable and unstable angina at a mean interval of 923 and 903 days, respectively. Two-year survival rates were 96% and 97% in the populations with unstable and stable angina, respectively. There were no significant differences with respect to bypass surgery and angioplasty, but event-free survival at 2 years was significantly lower in the unstable (54%) than the stable (69%) angina group. Quantitative coronary angiography did not detect any difference in luminal renarrowing during the 6-month angiographic follow-up period. Although directional coronary atherectomy can be performed effectively in patients with unstable and stable angina, the long-term clinical outcome was less favorable in the unstable angina group.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of coronary vessel size on renarrowing process and late angiographic outcome after successful balloon angioplasty

BACKGROUND

Although coronary angioplasty is increasingly applied in the treatment of multivessel disease and a broadening range of vessel size, the influence of vessel size itself on the late results of intervention is unresolved. An influence of vessel size on late outcome would carry implications for the application and evaluation of interventional devices, which are selectively used in larger or smaller vessels. The purpose of the present study was to investigate the influence of vessel size on both the restenosis process and late angiographic outcome in a large homogeneous patient group after successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS AND RESULTS

The study population comprised 3072 patients with 3736 successfully dilated native primary coronary artery lesions and satisfactory quantitative angiographic analysis in multiple identical projections before and after PTCA and at a 6-month follow-up. Late luminal loss, minimal luminal diameter (MLD) at follow-up, and net luminal gain, as well as percent diameter stenosis at follow-up, net gain in percent diameter stenosis, restenosis rates (according to three definitions), and net gain index, were all compared among nine equally sized groups (noniles) according to vessel size. A direct influence of vessel size on continuous measures of late result was also evaluated by linear regression. These evaluations provided conflicting information with no consistent influence of vessel size emerging. To elucidate the independent influence of vessel size on the restenosis process (late loss) and late angiographic outcome (MLD at follow-up), multiple linear regression analysis was performed taking into account luminal gain, preprocedural MLD, and lesion location. In this manner, vessel size was found to be exert a significantly positive influence on MLD at follow-up (P < .0001) and an equally negative effect on loss. Correcting for vessel size by using percent stenosis measurements led to an anticipated neutralization of this influence. Lesion location in the left anterior descending coronary artery was found to be independently associated with greater loss and smaller MLD at follow-up (P < .0001).

CONCLUSIONS

Increasing coronary vessel size was found to be independently predictive of decreasing late luminal loss and increasing follow-up MLD after successful balloon angioplasty. Apparently superior or inferior late angiographic results of new interventional devices may thus be explained in part by preferential use in larger or smaller vessels, respectively. Devices that can safely optimize the short-term result of intervention may realize their ultimate long-term value in larger coronary vessels.