Long-term analysis of conventional coronary balloon angioplasty and an initial "stent-like" result. The NHLBI PTCA Registry

Reduced incidence of clinical restenosis with newer generation stents, stent oversizing, and high-pressure deployment: single-operator experience

BACKGROUND

Over the last 4 years, several newer generation stents have become available, promising to change the scenery of coronary angioplasty (PTCA) with its attendant restenosis rate.

HYPOTHESIS

The aim of this study was to review prospectively the results of a single operator adopting a uniform approach with approximately 0.5 mm stent oversizing and high-pressure (> or = 12-16 bar) deployment and compare them with conventional PTCA in a series of 244 consecutive patients.

METHODS

The study included 203 men and 41 women, aged 59 +/- 11 years, who presented with stable angina and/or positive exercise testing (n = 75), unstable angina (n = 161), or acute myocardial infarction (n = 8). Dilated vessels included the left anterior descending artery (n = 139), the right coronary artery (n = 86), the left circumflex artery (n = 47), the ramus branch (n = 4), or venous grafts (n = 2). Stents were implanted for dissection, suboptimal PTCA result, and electively. Two groups were compared: 83 patients who underwent balloon PTCA alone and 161 patients who also received stent(s).

RESULTS

The two groups had similar demographics, age (58 +/- 10 vs. 59 +/- 11 years), initial vessel stenosis (92 +/- 7 vs. 93 +/- 6%), and left ventricular ejection fraction (51 +/- 9 vs. 51 +/- 8%). Procedural success was also similar (97.6 vs. 99.4%), but as expected the residual stenosis was much lower in the stent group (< or = 0 vs. 17%). The following stents were employed: J & J (n = 1), NIR (n = 117), ACS (n = 59), AVE (n = 9), Inflow GoldFlex (n = 9), Crossflex (n = 5), Wictor (n = 1), Jostent (n = 16), R stent (n = 9), Seaquence (n = 2) and Wallstent (n = 1). Single stents were used in 118 patients, two stents in 31 patients, three in 6 patients, and four in 6 patients. There was one in-hospital death at 3 days unrelated to the procedure. There were no events of subacute stent thrombosis; all patients in the stent group received combined therapy with aspirin and ticlopidine, the latter for 1 month. During 18 +/- 14 months, the clinical restenosis rate was significantly lower in the stent group (6.9%) than in the PTCA group (28.4%) (p = 0.001).

CONCLUSION

In a series of 244 consecutive patients, newer generation stents and a consistent approach of stent oversizing and high-pressure stent deployment by a single operator resulted in high procedural success (99%), lack of stent thrombosis (0%), and a very low clinical restenosis rate (7%).

Impact of routine angiographic follow-up on the clinical benefits of paclitaxel-eluting stents: results from the TAXUS-IV trial

OBJECTIVES

The objectives of the study were to evaluate the effect of angiographic follow-up on revascularization rates in the TAXUS-IV trial and to determine whether the relative benefit of paclitaxel-eluting stent implantation compared with bare metal stent implantation was modified by angiographic follow-up.

BACKGROUND

Although several clinical trials have demonstrated that drug-eluting stents (DES) reduce restenosis compared with bare-metal stents (BMS), virtually all of these studies have incorporated angiographic follow-up.

METHODS

In the TAXUS-IV trial, 1,314 percutaneous coronary intervention patients were randomized to receive paclitaxel-eluting stents (PES) (n = 662) or identical-appearing BMS (n = 652). Clinical outcomes were compared, stratified by assignment to angiographic follow-up or clinical follow-up alone.

RESULTS

Compared with clinical follow-up alone, angiographic follow-up patients had a significantly higher rate of target vessel revascularization (TVR) at 1 year (adjusted hazard ratio [HR] 1.46; p = 0.04), with similar relative increases in PES and BMS patients. Because PES reduced TVR by approximately 60% regardless of type of follow-up, assignment to angiographic follow-up tended to overestimate the absolute benefit of PES relative to clinical follow-up alone. In contrast, assessment of end points immediately before the time of follow-up angiography led to substantial underestimation of the absolute benefit of PES implantation.

CONCLUSIONS

Performance of mandatory angiographic follow-up increases rates of TVR among patients receiving both BMS and PES and overestimates the absolute clinical benefits of PES relative to clinical follow-up alone. Nonetheless, PES substantially reduces TVR regardless of assignment to mandatory angiographic follow-up or not. Future studies designed to determine the true clinical benefits of DES should either forgo routine angiographic follow-up or separate the time of repeat angiography from the primary clinical end point by as long as possible.

Shortening the stent length reduces restenosis with bare metal stents: matched pair comparison of short stenting and conventional stenting

OBJECTIVE

To investigate the effect of reducing stent length on the rate of target lesion restenosis.

DESIGN

In a prospective investigation, acute and long term results of a short stenting procedure were analysed by quantitative angiography and compared with results of a conventional stenting procedure selected according to a matched pairs analysis.

PATIENTS

Short stents were implanted in 400 consecutive patients with 464 lesions and conventional stents in 430 patients. Demographic and lesion characteristics were comparable between groups.

INTERVENTIONS

In short stenting, the shortest stent length to cover only segments with > 30% reduction in vessel diameter was used. In conventional stenting, full coverage of a stenotic vessel segment was intended.

MAIN OUTCOME MEASURES

The mean stent lengths of the short stent group (9.8 (4) mm) and the conventional stent group (16.3 (7) mm) differed significantly (p < 0.0001); all other procedural and angiographic parameters were the same. Procedural success was similar for both groups. Control angiography after six months was conducted in 92% of patients.

RESULTS

Short stenting resulted in both less restenosis (68 of 431 (15.8%)) than conventional stenting (93 of 381 (24.4%), p = 0.007) and less late lumen loss (0.6 (0.6) mm v 0.75 (0.5) mm, p = 0.0001). Residual stenosis (< 45%) in adjacent vessel segments after short stenting did not affect the restenosis rate. Only the implantation of a < or = 9 mm stent predicted the absence of restenosis in a multivariate analysis.

CONCLUSION

Shortening the length of bare metal stents reduces the restenosis rate as compared with conventional stenting.

Outcomes of optimal or “stent-like”balloon angioplasty in acutemyocardial infarction: the CADILLAC trial

OBJECTIVES

We sought to compare outcomes between patients with acute myocardial infarction (AMI) undergoing percutaneous transluminal coronary angioplasty (PTCA) with an optimal or "stent-like" result versus patients who underwent routine stent placement.

BACKGROUND

Recent studies in patients with AMI undergoing stent implantation have suggested that PTCA may no longer be a relevant treatment modality for stent eligible lesions. However, whether routine stent placement is superior or necessary when an optimal PTCA or "stent-like" result is achieved is unknown.

METHODS

In the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial, 2,082 patients with AMI were randomly assigned to undergo PTCA alone, PTCA + abciximab, stenting alone, or stenting + abciximab. Outcomes were compared in patients achieving an optimal acute PTCA result (residual core laboratory diameter stenosis <30% without significant dissection) versus those assigned to routine stenting.

RESULTS

Optimal PTCA was achieved in 40.7% of patients randomized to balloon angioplasty, including 38.5% and 42.7% assigned to PTCA alone and PTCA + abciximab, respectively. Ischemic target vessel revascularization (TVR) at 30 days occurred more frequently after optimal PTCA than routine stenting (5.1% vs. 2.3%, p = 0.007). The one-year composite adverse event rate (death, reinfarction, disabling stroke, or TVR) was greater after optimal PTCA than routine stenting (21.9% vs. 13.8%, p < 0.001), driven largely by increased rates of ischemic TVR (19.1% vs. 9.1%, p < 0.001); no significant differences were present in the rates of death, reinfarction, or disabling stroke between the two groups. Angiographic restenosis also was more common with optimal PTCA than routine stenting (36.2% vs. 22.2%, p = 0.003). Even a post-PTCA diameter stenosis of <20% (realized in 12% of patients) did not result in outcomes equivalent to stenting.

CONCLUSIONS

Even if an optimal result is achieved after primary PTCA in AMI, early and late outcomes can be further improved with routine stent implantation.

One-year outcome after percutaneous coronary intervention for stable and unstable angina pectoris with or without application of general usage of stents in unselected European patient groups

The outcome after percutaneous coronary intervention (PCI) of all patients treated for stable and unstable angina pectoris from July 1992 to June 1993 (group A [n = 590], of whom 3.7% received stents) was compared with the outcome in patients treated from July 1996 to June 1997 (group B [n = 768], of whom 64.7% received stents). All patients were followed up for at least 1 year. PCI was performed due to unstable angina in 34.1% and 33.5% of patients in groups A and B, respectively. More patients in group B than in group A had systemic hypertension, previous coronary artery bypass grafting, and PCI. Within 1 year, 42.2% of patients in group A versus 27.2% in group B (p <0.001) either died, had a nonfatal acute myocardial infarction (AMI), or underwent a new revascularization procedure. The difference between the groups persisted after correction for differences in baseline characteristics. No difference was seen in the subgroup that had previously undergone PCI. Mortality (2.0% vs 1.4%, p = NS) and the composite of death plus AMI (6.6% vs 6.1%, p = NS) was similar in groups A and B. The diagnoses of unstable angina and systemic hypertension at the time of the procedure were also predictors of adverse outcome. Thus, in a cohort of patients treated after the general acceptance of stenting, the composite of death, AMI, and/or revascularization procedures was significantly less than that in the cohort treated before this increase in stenting. However, this did not result in a reduced frequency of death or AMI.

Angiographic classification of coronary dissections after plain old balloon angioplasty for prediction of regression at follow-up

Coronary dissection after plain old balloon angioplasty often shows regression during follow-up. This study sought to determine whether we can predict such phenomenon angiographically. We analyzed 64 patients with 71 type B-D coronary dissections determined by the National, Heart, Lung, and Blood Institute (NHLBI) criteria. Regression was considered present when minimal lumen diameter increased by more than 0.3 mm during follow-up. Dissections were divided into subgroups using the NHLBI criteria and our classification in which type a and b dissections were characterized by the width of a dissection lumen exceeding one quarter of the reference diameter with the outer edge of the dissection lumen within the boundary of reference in type a and beyond it in type b. In type c and type d dissections, the width of the dissection lumen was within one quarter of the reference with its outer edge within the boundary of reference in type c and beyond it in type d. Type e dissection had a protruding flap or spiral appearance. Regression was recognized in 23.9%. The distribution of dissection types was similar in the groups with and without regression by the NHLBI criteria, but type c dissection had regression more frequently than the other types of coronary dissections (p<0.001) using our classification.

The role of acute wall recoil and late restenosis: results of the OCBAS trial (Optimal Coronary Balloon Angioplasty with Provisional Stenting versus Primary Stent)

Early deterioration of minimal luminal diameter immediately after PTCA, has been associated with an increase of late restenosis. Lesions with no early loss after PTCA have a low restenosis rate. Coronary stents reduce restenosis in lesions exhibiting early wall recoil. The purpose of the OCBAS study was to compare two strategies during coronary interventions; provision vs. elective stenting. 116 patients with good PTCA results were randomized to stent (n = 57) or to optimal PTCA (n = 59). After randomization in PTCA group, 13.5% of the patients crossed over to stent due to early loss (provisional stenting). Baseline demographic and angiographic characteristics were similar in both groups of patients. At 7.6 months, 96.6% of the entire population had a follow-up angiographic study; 98.2% in the stent and 94.9% in the PTCA group. Immediate and follow-up angiographic data showed that acute gain was significantly higher in the stent than in the PTCA group (1.95 vs. 1.5 mm; P < 0.03). However, late loss was significantly higher in the stent than the PTCA groups (0.63 +/- 0.59 vs. 0.26 +/- 0.44, respectively; P = 0.01). Hence, net gain with both techniques was similar (1.32 +/- 0.3 vs. 1.24 +/- 0.29 mm for the stent and PTCA groups respectively; P = NS). Angiographic restenosis rate at follow-up (19.2% in stent vs. 16.4% in PTCA; P = NS) and TVR (17.5 in stent vs. 13.5% in PTCA; P = NS) were also similar. Furthermore, event-free survival was 80.8% in the stent versus 83.1% in the PTCA group (P = NS). Overall costs (hospital and follow-up) were US$591,740 in the stent versus US$398,480 in the PTCA group (P < 0.02). The strategy of the PTCA with delay angiogram and provisional stent if early loss occurs, had similar restenosis rate and TVR than universal use of bare stents.

Intravascular-ultrasound-guided percutaneous transluminal coronary angioplasty/provisional stent implantation strategy: impact on long-term clinical follow-up

Two hundred and eighty-four consecutive patients with 438 native coronary artery stenoses were enrolled prospectively in a study of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary angioplasty (PTCA) with provisional stenting: (1) aggressive lesion-site media-to-media balloon-sizing; (2) IVUS-assessment of residual lumen dimensions to identify optimal PTCA results (minimum lumen area = 65% of the average of the proximal and distal reference lumen areas or = 6.0 mm(2) and no major dissection); and (3) liberal stent crossover. Overall, 206 stenoses in 134 patients (47%) were treated with PTCA alone. Reasons for crossover were flow-limiting or lumen-compromising dissections in 28% of patients and suboptimal IVUS minimum lumen area in 72% of patients. At one year, 8% of stenoses in the PTCA group and 16% in the stent crossover group required revascularization. In approximately half of the patients treated using an IVUS-guided aggressive PTCA strategy, stent implantation could be avoided without sacrificing an increase in acute complications or worse clinical outcome.

Achieving optimal results with standard balloon angioplasty: can baseline and angiographic variables predict stent-like outcomes?

OBJECTIVES

To predict which patients might not require stent implantation, we identified clinical and angiographic characteristics associated with repeat revascularization after standard balloon angioplasty.

BACKGROUND

Stents reduce the risk of repeat revascularization but are costly and may lead to in-stent restenosis, which remains difficult to treat. Identification of patients at low risk for repeat revascularization may allow clinicians to reserve stents for patients most likely to benefit.

METHODS

Data from five interventional trials (5,146 patients) were pooled for analysis. We identified patients with optimal angiographic results (final diameter stenosis < or =30% and no dissection) after balloon angioplasty and determined the multivariable predictors of repeat revascularization.

RESULTS

Optimal angiographic results were achieved in 18% of patients after angioplasty. The repeat revascularization rate at six months was lower for patients with optimal results (20% vs. 26%, p < 0.001) but still higher than observed in stent trials. Independent predictors of repeat revascularization were female gender (odds ratio [OR] 1.67, p = 0.01), lesion length > or =10 mm (OR 1.62, p = 0.03) and proximal left anterior descending coronary artery lesions (OR 1.62, p = 0.03). For the 8% of patients with optimal angiographic results and none of these risk factors, the repeat revascularization and target vessel revascularization rates were 14% and 8% respectively, similar to rates after stent implantation. Cost analysis estimated that $78 million per year might be saved in the U.S. with a provisional stenting strategy using these criteria compared with elective stenting.

CONCLUSIONS

A combination of baseline characteristics and angiographic results can be used to identify a small group of patients at very low risk for repeat revascularization after balloon angioplasty. Provisional stenting for these low risk patients could substantially reduce costs without compromising clinical outcomes.

Randomized comparison of primary stenting and provisional balloon angioplasty guided by flow velocity measurement. Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II Study Group

BACKGROUND

Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may have other disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive.

METHODS AND RESULTS

To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is "optimal." An optimal result was defined as a flow reserve >2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; P:=0.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P:=0. 066).

CONCLUSIONS

After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.

Randomized comparison of elective stent implantation and coronary balloon angioplasty guided by online quantitative angiography and intracoronary Doppler. DESTINI Study Group (Doppler Endpoint STenting INternational Investigation)

BACKGROUND

The purpose of this study was to compare long-term outcomes of coronary stenting in all lesions (elective stenting) or only in lesions with inadequate morphological and functional results after balloon angioplasty (guided PTCA).

METHODS AND RESULTS

Treatment of multivessel disease, with any lesion length and vessel size, was allowed provided that all lesions were suitable for stent implantation. Patients were randomized to elective stent implantation (n=370) or guided PTCA (n=365). An optimal PTCA result (residual diameter stenosis </=35%, coronary flow reserve measured with a Doppler guidewire >2.0, absence of threatening dissections) was achieved in 166 lesions (43%). The remaining 218 lesions underwent stent implantation (provisional stenting). Final residual diameter stenosis was lower in the elective and provisional stent groups (9.3% and 10.2%) than in the optimal PTCA group (24.8%, P:<0. 00001). On an intention-to-treat analysis, the probability of >/=1 major adverse cardiac event at 12 months was 17.8% in the elective stenting group and 18.9% in the guided PTCA group (20.1% for optimal PTCA and 18.0% for the provisional stenting subgroup, P:=NS). The incidence of repeat target lesion revascularization at 1 year was 14. 9% in the elective stent group and 15.6% in the guided PTCA group (17.6% for optimal PTCA and 14.1% for the provisional stenting subgroup, P:=NS).

CONCLUSIONS

When balloon angioplasty is guided by online quantitative angiography and Doppler-derived coronary flow reserve, with provisional stenting reserved for suboptimal results, early and late clinical outcomes are comparable to those achieved by elective stenting of all patients.

Provisional stenting strategies: systematic overview and implications for clinical decision-making

Coronary stents reduce the rates of abrupt closure, emergency coronary artery bypass graft surgery and restenosis, but do not prevent myocardial infarction or death at six months. The financial burden of increased stent use and the difficulty in managing in-stent restenosis have provided the impetus to develop provisional stenting strategies. Patients at low risk for restenosis after balloon angioplasty may not derive additional benefit from stent implantation and may be successfully managed with percutaneous transluminal coronary angioplasty (PTCA) alone. Numerous patient, lesion and procedural predictors of restenosis have been identified. Postprocedural assessment using quantitative coronary angiography, intravascular ultrasound (IVUS), coronary flow velocity reserve (CVR) or fractional flow reserve (FFR) may further enhance the ability to predict adverse outcomes after PTCA. Several studies have been performed to investigate the feasibility of provisional stenting strategies using various modalities to identify low risk patients who could be managed with PTCA alone. An optimal or "stent-like" angiographic result after PTCA is associated with favorable clinical outcomes. Preliminary results of studies using IVUS or CVR to guide provisional stenting appear promising. Angiography alone may be inadequate to identify truly low risk patients and may need to be combined with clinical factors, assessment of recoil, IVUS or physiologic indexes. Strategies that avoid unnecessary stenting in even a small proportion of patients may have large impacts on health care costs. Provisional stenting may potentially reduce costs and rates of in-stent restenosis without compromising the quality of health care delivery.

[The practical clinical guidelines of the Sociedad Española de Cardiología on interventional cardiology: coronary angioplasty and other technics]

Interventional cardiology has had an extraordinary expansion in last years. This clinical guideline is a review of the scientific evidence of the techniques in relation to clinical and anatomic findings. The review includes: 1. Coronary arteriography. 2. Coronary balloon angioplasty. 3. Coronary stents. 4. Other techniques: directional atherectomy, rotational atherectomy, transluminal extraction atherectomy, cutting balloon, laser angioplasty and transmyocardial laser and endovascular radiotherapy. 5. Platelet glycoprotein IIb/IIIa inhibitors. 6. New diagnostic techniques: intravascular ultrasound, coronary angioscopy, Doppler and pressure wire. For the recommendations we have used the classification system: class I, IIa, IIb, III like in the guidelines of the American College of Cardiology and the American Heart Association.

Acute and long-term results of an intravascular ultrasound-guided percutaneous transluminal coronary angioplasty/provisional stent implantation strategy

Two hundred eighty-four consecutive patients with 438 native coronary artery stenoses were enrolled prospectively in a study of intravascular ultrasound (IVUS)-guided provisional percutaneous transluminal coronary angioplasty (PTCA): (1) IVUS-guided, aggressive lesion-site media-to-media balloon sizing, (2) IVUS assessment of residual lumen dimensions to identify optimal PTCA results (minimum lumen area > or =65% of the average of the proximal and distal reference lumen areas or > or =6.0 mm2 and no major dissection), and (3) liberal stent crossover. Overall, 206 stenoses in 134 patients were treated with PTCA alone. Reasons for crossover were flow-limiting or lumen compromising dissections in 28% of patients or a suboptimal IVUS minimum lumen area in 72% of patients. Sixty-three stenoses (27%) were treated with Gianturco-Roubin stents and 169 (73%) with Palmaz-Schatz stents. The clinical success rate and major in-hospital complication rates were similar in the optimal PTCA and stent crossover groups. At 1 year, 42 patients (15%) with 53 stenoses (12%) underwent revascularization: 8% of stenoses in the PTCA group and 16% in the stent crossover group. In approximately half of the patients treated using an IVUS guided aggressive PTCA strategy, stent implantation could be avoided without sacrificing an increase in acute complications or late clinical outcome. This provides an alternative strategy for interventionalists less inclined to use routine elective stenting.