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

Infrainguinal Arterial Intervention: Is There a Role for an Atherectomy Device?

Excision of atheromatous plaque is an attractive option for the minimally invasive treatment of peripheral arterial disease. Approved for use in 2003, the SilverHawk Plaque Exicison System (FoxHollow Technologies, Redwood City, CA) is a catheter-based plaque excision device allowing percutaneous removal of atheromatous material. This device represents the most recent generation of atherectomy tools. Overall experience with plaque debulking in the peripheral arteries spans almost two decades, and understanding of the technique continues to evolve. This article reviews the technology, current practices, and data on plaque excision.

Directional coronary atherectomy: a time for reflection. Should we let it go?

A series of interventional tools have emerged since the advent of percutaneous coronary angioplasty. Several are fundamental and used routinely, while others less favourable have fallen short of mainstream therapy and/or have settled as a niche device. We present an overview of the evolution of directional coronary atherectomy (DCA), a unique device that was originally conceived in 1984 to solve the limitations of balloon angioplasty. Unfortunately, we have witnessed its use fall significantly out of favour due to premature and controversial study results. In many interventional laboratories DCA is no longer available. However, we strongly feel that allowing DCA to join the list of extinct interventional tools would be very unfortunate. We, herein, present a series of complex percutaneous coronary procedures to illustrate the convenience of DCA use as a lesion-specific niche device. Finally, DCA offers a valuable distinct clinical research function as it allows for in vivo pathological coronary tissue examination. In conclusion, we plead for its continued production and use as an interventional niche device for the wellbeing of our patients.

Directional atherectomy before stenting versus stenting alone in percutaneous coronary interventions: A meta-analysis

Plaque debulking before stenting is still controversial. We performed a meta-analysis of 12 randomized and non-randomized trials comparing directional coronary atherectomy (DCA) before stenting versus stenting alone. Angiographic end points were acute gain, late loss and angiographic restenosis rate. Clinical end points were early major adverse cardiac events [MACEs: death, Q-wave myocardial infarction (MI), non-Q-wave MI], late MACEs (death, Q-wave MI) and target lesion revascularization (TLR). Data are expressed as odds ratio (OR) with 95% confidence intervals (CI) or weighted mean difference (WMD) with 95% CI, as appropriate. A total of 1216 patients undergoing DCA before stent and 1484 patients undergoing stent alone have been included. DCA before stent was associated to a better acute gain compared to stenting alone (WMD 0.23, [0.18-0.28]; p<0.0001), to a striking reduction of angiographic restenosis rate (OR of 0.67, [0.54-0.84], p=0.0003) and to a significantly lower rate of late TLR (OR 0.73 [0.59-0.91], p=0.006). Late loss did not differ between the two groups (WMD 0.00 [-0.08 and 0.08], p=0.98). We found a higher rate of early MACEs for the combined approach (OR 1.87 [1.16-3.02], p=0.01), with similar prevalence of late MACEs (OR 0.83 [0.65-1.06], p=0.13). In conclusion, this meta-analysis demonstrates that DCA before stenting is superior to stenting alone with regard to acute angiographic results and TLR with a similar prevalence of late MACEs. The higher prevalence of early MACEs with DCA before stenting, however, is disturbing and probably related to distal embolization.

Contemporary Stent Treatment of Coronary Bifurcations

Treatment of coronary bifurcation lesions represents a challenging area in interventional cardiology. The introduction of drug-eluting stents (DES) reduced restenosis in the main branch (MB). However, restenosis at the ostium of the side branch (SB) remains a problem. Although stenting the MB with provisional SB stenting seems to be the prevailing approach, in the era of DES various two-stent techniques emerged (crush) or were re-introduced (V or simultaneous kissing stents, crush, T, culottes, Y, skirt) to allow stenting in the SB when needed. This review describes in detail various techniques used for implantation of two stents by intention to treat.

Stent restenosis in a Chinese population

BACKGROUND

Stents are now widely used in Hong Kong and China and there is a clinical impression that restenosis is less common because of the lower prevalence of coronary artery disease and associated risk factors in the Chinese. However, there are no published data on angiographic stent restenosis rates in Chinese patients.

METHOD

In a prospective study of 114 consecutive Chinese patients who underwent coronary stenting, quantitative coronary analyses were made at the time of stent implantation and subsequently at 6 months post-stenting (n = 97).

RESULTS

At 6 months, restenosis (> or = 50% diameter stenosis in the dilated segment) was present in 42 (43.3%) of the 97 patients and 54 (33.5%) of the total 161 lesions stented. Vessel reference diameter (VRD) of < 3 mm and stented length of > or = 18 mm were associated with higher restenosis rates (36% and 38%). Compared to those without, those with restenosis had a greater residual stenosis of 16.53+/-11.54% and smaller final minimal luminal diameter (MLD) of 2.41+/-0.49 mm, (p < 0.01 and p < 0.008 respectively). Standard coronary risk factors were not associated with a higher rate of restenosis. Lesion morphology was significantly associated with restenosis.

CONCLUSION

Coronary stenting in Hong Kong Chinese patients is associated with a restenosis rate comparable to that demonstrated in previously published trials from populations in the West.

Directional coronary atherectomy plus stent implantation vs. left internal mammary artery bypass grafting for isolated proximal stenosis of the left anterior descending coronary artery

The aim of this study was to compare the short- (< 30 days) and long-term (> or = 30 days) clinical outcomes of left internal mammary artery bypass grafting (LIMA-LAD) and directional coronary atherectomy plus stent implantation (DCA + stent) in the treatment of isolated proximal left anterior descending coronary (LAD) lesions. One hundred and twenty-six patients underwent LIMA-LAD and 132 consecutive patients underwent DCA + stenting. The primary endpoint was the incidence of short- and long-term major adverse cardiac events (MACE); the secondary endpoints included any periprocedural events and long-term target vessel revascularization (TVR). We found no significant between-treatment difference in the occurrence of short-term MACE, and the long-term MACE rate per 100 person-years was 3.0 in the LIMA-LAD group and 4.6 in the DCA + stent group. After 5-year follow-up, 79% of the patients in the DCA + stent group and 89% of those in the LIMA-LAD group were still MACE-free. The risk of any periprocedural events was six times lower in the DCA + stent group, and the risk of TVR was six times higher. We conclude that both procedures lead to good short- and long-term follow-up results in isolated proximal LAD disease. As fewer periprocedural events and more TVRs occur after DCA + stenting than after LIMA-LAD, they can be considered valuable alternatives to each other.

Stenting after directional coronary atherectomy compared with directional coronary atherectomy alone and stenting alone: a serial intravascular ultrasound study

BACKGROUND

Directional coronary atherectomy prior to stent implantation (DCA-stent) is expected to be an effective approach to reduce restenosis. The purpose of this study was to determine whether DCA-stent has advantages over DCA alone or stenting alone using serial intravascular ultrasound (IVUS).

METHODS AND RESULTS

Serial (pre-, post- and follow-up) IVUS was performed in 187 native coronary lesions treated with each of the 3 strategies. External elastic membrane cross-sectional area (CSA), lumen CSA and plaque CSA were measured. Baseline characteristics were similar. Postprocedural lumen CSA was largest after DCA-stent (11.2+/-2.7 mm2) and DCA (10.8+/-2.5 mm2) than stenting alone (9.0+/-2.9 mm2) (p<0.0005). Follow-up lumen loss was similar. As a result, follow-up lumen CSA was largest after DCA-stent (DCA-stent: 9.1+/-3.4 mm2, DCA: 7.8+/-4.2 mm2, stent: 6.3+/-2.6 mm2, p<0.0005). There was a trend toward a lower rate of restenosis with DCA-stent (DCA-stent, 12.5%; DCA, 18.3%; stent, 18.8%; p=0.57).

CONCLUSIONS

DCA-stent is superior to both DCA alone and stent alone in terms of the ability to gain a larger lumen as assessed by IVUS.

Comparison of directional coronary atherectomy and stenting versus stenting alone for the treatment of de novo and restenotic coronary artery narrowing

Late lumen loss after directional coronary atherectomy (DCA) is mainly determined by arterial remodeling. We hypothesized that stent implantation after optimal lesion debulking could be an effective approach to reduce restenosis. A total of 753 patients with de novo or restenotic coronary lesions were prospectively randomized to DCA plus stenting (n = 381) or stenting alone (n = 372). The patients were followed for 12 months. Procedural success was achieved in 91.5% versus 97.3% (p = 0.0007) of patients treated with DCA plus stent versus stent alone. Optimal atherectomy (<20% residual stenosis) was achieved in 26.5% of patients. The final minimal luminal diameter and the acute gain were similar in the 2 groups. There was no increase in 30-day major adverse cardiac events in the DCA plus stent group (3.9% vs 2.4%, p = 0.30). The primary end point, angiographic restenosis at 8 months, occurred in 26.7% of patients treated with DCA plus stents and in 22.1% of patients treated with stents alone (p = 0.237). Clinical follow-up to 1 year showed no difference in mortality (1.3% vs 0.8%, p = 0.725), acute myocardial infarction (4.2% vs 3.5%, p = 0.706), and target vessel failure (composite of death, Q-wave myocardial infarction, and target vessel revascularization) (23.9% vs 21.5%, p = 0.487) between patients with DCA plus stents and those with stents alone. This study failed to support the hypothesis that DCA before stenting lowers the angiographic restenosis rate compared with stents alone. At 12-month follow-up, there were no significant differences between the 2 groups in rates of death, reinfarction, or target vessel failure.

Initial experience with a new 8 French-compatible directional atherectomy catheter: Immediate and mid-term results

The purpose of this study was to evaluate the safety and efficacy of the new Fox Hollow atherectomy device (FHT) designed for more efficient and easier plaque removal. The FHT has short rigid section and low-profile cutter mounted on a monorail catheter. The FHT catheter was utilized in 77 patients with 98 lesions. Mean reference vessel diameter was 2.75 +/- 0.51 mm. Successful atherectomy with tissue retrieval was performed in 94 lesions (96%). Following atherectomy, mean diameter stenosis was reduced from 71.1% to 31.9% and further to 10.4% following adjunctive treatment. Angiographic complications were one coronary perforation and one adventitial staining, both successfully treated with prolong balloon inflation and stent implantation. Nine patients (11.7%) had in-hospital non-Q-wave myocardial infarction (MI). One patient died (1.3%) for noncardiac reasons and one had MI (1.3%) at 6-month follow-up. Target lesion revascularization was required in 13 (13.8%) lesions and target vessel revascularization in 15 (20.3%) patients. There was target vessel failure in 17 (23.0%) patients. Plaque debulking with the FHT catheter can be performed safely and effectively in relatively small vessels and complex lesions located in mid-distal artery segments with 6-month clinical outcome similar to prior atherectomy devices.

Clinical and angiographic outcome of directional atherectomy followed by stent implantation in de novo lesions located at the ostium of the left anterior descending coronary artery

BACKGROUND

Lesions located at the ostium of the left anterior descending coronary artery (LAD) are considered an ideal target for directional atherectomy (DCA), but few data are available about the value of using this strategy before stenting in comparison with stenting alone.

OBJECTIVES

To investigate the immediate and mid term clinical and angiographic results of DCA followed by stent implantation for ostial LAD lesions.

DESIGN

Retrospective comparison of the immediate and mid term angiographic and clinical results of a series of 117 consecutive patients with de novo lesions located at the ostium of the LAD. Of these, 46 underwent DCA before stenting and 71 were treated with stenting alone.

RESULTS

Technical success in the two groups was similar at around 98%. DCA plus stenting provided a larger minimum lumen diameter at the end of the procedure than stenting alone (3.57 (0.59) mm v 3.33 (0.49) mm, p = 0.022). There were no differences for in-hospital major adverse events (MACE) (7.5% for atherectomy plus stenting, and 5.3% for stenting alone; p = 0.41). All patients had clinical follow up at a mean of 7.9 (2.7) months. Angiographic follow up was done in 89 patients (76%) at a mean of 5.9 (2.2) months. The atherectomy plus stenting group had a larger minimum lumen diameter than the stenting group (2.79 (0.64) mm v 2.26 (0.85) mm, p = 0.004) and a lower binary restenosis rate (13.8% v 33.3%, p = 0.031). Six month MACE were reduced in the atherectomy plus stenting group (8.7% v 23.9%, p = 0.048).

CONCLUSIONS

Debulking before stenting in de novo lesions located at the ostium of the LAD is safe and is associated with a high rate of technical success. Follow up data show that DCA plus stenting results in a significantly larger minimum lumen diameter and a lower incidence of restenosis than stenting alone.

Effect of plaque debulking before stent implantation on in-stent neointimal proliferation: a serial 3-dimensional intravascular ultrasound study

BACKGROUND

Recent intravascular ultrasound (IVUS) studies have suggested that plaque burden has a role in promoting intimal hyperplasia after stenting. We report on volumetric assessments of in-stent neointimal formation with 3-dimensional IVUS analysis, comparing directional coronary atherectomy (DCA) plus stenting (DCA/stenting) to stenting without DCA.

METHODS

Twenty-four patients (24 lesions) treated with DCA before stenting were matched to 24 patients (24 lesions) receiving stenting without DCA. All stents were a single Multilink stent. In both groups, serial IVUS was performed before and after intervention and during the 6-month follow-up period. The arterial segments that were analyzed with a computer-based contour detection program were the same as the stented segments analyzed on serial studies. These measurements were obtained: (1) lumen volume (LV), (2) stent volume (SV), (3) vessel volume (VV), (4) in-stent neointimal volume (ISV) calculated as SV-LV, and (5) percent in-stent neointimal volume (%ISV) calculated as ([SV-LV]/SV) x 100.

RESULTS

Baseline characteristics of the 2 groups were similar. After intervention, both groups achieved similar LV (140.0 mm(3) DCA/stenting vs 135.2 mm(3) stenting alone). However, the follow-up ISV and %ISV were significantly smaller in the DCA/stenting group (19.6 +/- 12.2 mm(3) DCA/stenting vs 44.6 +/- 29.5 mm(3) stenting alone; P =.00040; 15.3% +/- 10.6% DCA/stenting vs 31.5% +/- 17.7% stenting alone; P =.00040). Consequently, the DCA/stenting group showed a significantly greater follow-up LV (121.0 +/- 51.5 mm(3) DCA/stenting vs 91.5 +/- 26.7 mm(3) stenting alone; P =.016).

CONCLUSIONS

Plaque removal with DCA before stenting inhibits in-stent neointimal hyperplasia.

Effectiveness of adjunctive stent implantation following directional coronary atherectomy for treatment of left anterior descending ostial stenosis

The aim of this study was to evaluate the acute and long-term angiographic and clinical results of optimal plaque debulking by means of directional coronary atherectomy (DCA) followed by stent implantation for treatment of left anterior descending (LAD) ostial stenosis. Eighty consecutive patients (66 men; aged 57 +/- 10 years) with angina pectoris, documented anterior myocardial ischemia, and de novo LAD ostial stenosis prospectively underwent DCA and stent deployment. They were evaluated angiographically after 6 months and clinically for up to 30 +/- 29 months. The primary success rate was 98%. The in-hospital complications were 1 death due to in-stent subacute thrombosis 7 days after the procedure, 1 non-Q-wave myocardial infarction, and 1 retrograde left main artery dissection. The angiographic binary restenosis rate was 14.5%, and the loss index was 0.38 +/- 0.35. The target lesion revascularization (TLR) rates at 6, 12, and 24 months were 6.0%, 14.5%, and 16.3%, respectively, and the combined event rates (death, nonfatal myocardial infarction, TLR) at the same times were 8.7%, 17.5%, and 21.2%, respectively. These results indicate that the combined approach of DCA and stent implantation is feasible and safe in patients with LAD ostial lesions, has a high success rate, a low incidence of restenosis, and a good long-term outcome.

Effective plaque removal with a new 8 French-compatible atherectomy catheter

The purpose of this study was to evaluate the safety and efficacy of the new 8 Fr guide catheter-compatible Flexicut directional atherectomy device and to compare it with the conventional Atherocath GTO catheter. The 6 Fr Flexicut catheter has a larger cutting window and a titanium nitride-coated cutter to effect more tissue removal as well as treat mildly calcified lesions. A group of 143 lesions in 117 consecutive patients treated with the Flexicut catheter in four centers were compared with a control group of 277 lesions in 212 consecutive patients treated with the GTO device. Postatherectomy luminal diameters were larger (2.92 +/- 0.79 vs. 2.52 +/- 0.64 mm; P < 0.0001), with more luminal gain (relative gain: 0.58 +/- 0.24 vs. 0.48 +/- 0.25; P = 0.0007) using fewer directional coronary atherectomy (DCA) cuts (12 +/- 7 vs. 16 +/- 9; P = 0.0001) in the Flexicut group. A residual diameter stenosis < 20% immediately after DCA was obtained in 77% of the lesions in the Flexicut group vs. 45% in the GTO group (P < 0.0001). Histology in the former group revealed large calcium speckles in the retrieved specimens. In the Flexicut group, there was a lower incidence of access site complications and damage to the coronary ostium (2.5% vs. 7.5%; P = 0.08). The new Flexicut catheter is more effective than the conventional GTO catheter with a trend for reduced guiding catheter-related complications.

Preliminary experience with the Xtrak debulking device in the treatment of peripheral occlusions

PURPOSE

To report our initial experience with a new rotary debulking device designed for treating long, diffusely diseased arterial segments.

METHODS

Ten symptomatic patients (8 men; mean age 63 years, range 34-76) with occluded superficial femoral (n = 6) or popliteal (n = 4) arteries were enrolled into a study to evaluate the debulking capabilities of a rotational atherectomy device. Occlusion length ranged from 4.0 to 16.1 cm (mean 11.1 +/- 4.10). The occlusions were treated with a low-speed, over-the-wire rotary device featuring a flexible, spiral "corkscrew" that embeds itself in the obstructive material while a rotary cutting catheter simultaneously cuts and captures the obstruction in a single pass.

RESULTS

The device cut and retrieved material in a single pass from all segments without device-related complications. The captured material consisted of a mixture of atherosclerotic plaque and thrombus. Minimum lumen diameters (MLD) increased from 0.0 to 2.2 +/- 1.09 mm (p<0.05) after Xtrak treatment and to 4.09 +/- 1.20 mm (p<0.05) after adjunctive balloon dilation, which was used in 8 of 10 segments. All patients improved clinically after the procedure, with an increased the mean ankle-brachial index sustained at 6 months (0.69 +/- 0.32, p<0.05 compared to baseline and 1-month measurements). Six months after the procedure, 7 patients remained free of clinical symptoms, while 3 patients required a subsequent intervention.

CONCLUSIONS

These initial results demonstrate that the Xtrak device can safely debulk long segments of diffusely diseased arteries in a single pass while simultaneously retrieving the occluding material. Supplementary angioplasty may be required in the majority of cases. Larger studies are required to determine whether debulking followed by balloon dilation improves the long-term prognosis in patients with chronic lower limb occlusions.

Diffuse in-stent restenosis

Stent restenosis, especially the diffuse pattern, has developed into a significant clinical and economical problem. It has been estimated that up to 250,000 patients developed in-stent restenosis in 2,000 alone, two thirds of them can be expected to have diffuse in-stent restenosis, which is difficult to treat because of high recurrence rates. None of the conventionally available interventional treatment modalities provides optimal long-term results. Intravascular radiation therapy is currently the only effective percutaneous therapy for combating in-stent restenosis. Late thrombotic complications have largely been eliminated by extended antiplatelet regimens. Geographical miss, a major reason for recurrence of in-stent restenosis after brachytherapy, can be reduced by an improved radiation technique. The first preliminary data on drug-eluting stents, showing only minimal neointimal proliferation at 6-month postimplantation, could represent a major breakthrough in the quest to solve restenosis.

The use of mechanical devices as adjuncts to intracoronary stenting

A number of mechanical adjuncts to intracoronary stenting are now available to the interventional cardiologist. These devices have assisted in the development of a safer and more effective stenting practice. Intravascular ultrasound-guided stenting has been shown to reduce the rate of subacute thrombosis and subsequent restenosis. It allows a greater appreciation of lesion structure and severity so that an appropriate intervention strategy can be devised. Debulking techniques may allow the optimal deployment of stents so that restenosis is reduced; however, the results of large randomized studies are still awaited. The use of thrombectomy and distal embolization protection devices is emerging as a safer alternate to stenting alone in difficult patient subsets, such as those with thrombus-laden lesions and degenerated vein grafts. Doppler and pressure wires may be useful in determining optimal stent deployment and predict subsequent patient outcomes. An understanding of the indications and limitations of these devices is of increasing importance to the interventional cardiologist as the coming decade threatens to yield an impressive array of high-tech innovations.

Directional atherectomy prior to stenting in bifurcation lesions: a matched comparison study with stenting alone

The ideal catheter-based intervention for treatment of coronary lesions at bifurcation site still has to be defined. The aim of the study was to assess the acute and long-term outcome after treatment of bifurcation lesions with directional atherectomy (DCA) and stenting in comparison with stenting alone. Thirty-one consecutive patients treated for bifurcation coronary lesions (62 lesions) with DCA and stenting in at least one branch (DCA group) were compared with a matched group of 31 patients with bifurcation coronary lesions (62 lesions) treated with stenting alone in at least one branch (non-DCA group). Procedural success was 87.1% in the DCA group compared with 100% in the non-DCA group (P = 0.03). In-hospital major adverse cardiac events (MACE) occurred only in the DCA group (12.9% vs. 0%, P = 0.03), mainly non-Q-wave myocardial infarction. After the procedure, minimum lumen diameter (MLD) and acute gain were significantly greater (P = 0.004 and P = 0.05, respectively) and % diameter stenosis was significantly lower (P = 0.05) in the main branch in the DCA group. At follow-up angiogram, MLD in the main branch was still significantly greater in the DCA group compared to the non-DCA group (2.31 vs. 1.65, respectively, P = 0.04), with no significant difference in late loss and loss index between the two groups. Restenosis rate was 28.8% in the DCA group vs. 43.5% in the non-DCA group (P = 0.13). The incidence of follow-up MACE was 29% in the DCA group compared with 48.4% in the non-DCA group, mainly due to target lesion revascularization. In conclusion, treatment of bifurcation coronary lesions with DCA and stenting was associated with greater acute gain after the procedure and greater MLD at follow-up in the main branch compared with stenting alone. Procedural myocardial infarction was more frequent in the DCA group. Restenosis rates and follow-up MACE were lower following DCA and stenting, without reaching any statistical significance.

Immediate and long-term results of "T" stenting for bifurcation coronary lesions

The technique of "T" stenting, which incorporates wiring both the branches of a bifurcation lesion, dilating a balloon in the main branch during stent deployment in the side branch followed by deployment of stent in the main branch, provides excellent immediate results in terms of technical and procedural success. However, further innovations are mandated to optimize the long-term outcome, which with a restenosis rate of 63%, can be described as not encouraging.

Stent placement for ostial left anterior descending coronary artery stenosis: acute and long-term (2-year) results

This study was performed to assess the acute and long-term results of elective stenting for the treatment of ostial left anterior descending coronary artery (LAD) stenosis. One hundred and eleven consecutive patients with ostial LAD stenting were included for this study. Follow-up angiography was performed at 6 months and clinical evaluation at regular intervals after stenting. Procedural success rate was 97.3%. Four patients developed non-Q myocardial infarction and one patient underwent emergency bypass surgery due to a large dissection after stenting. Angiographic restenosis rate was 26.1% (18/69), and target lesion revascularization rate 11.7%. The final luminal diameter after stenting was the only predictor of angiographic restenosis. Clinical follow-up was obtained in all patients at 21.5 +/- 16.0 months. Two patients died during the follow-up. Event-free survival rate was 84.6 +/- 3.8%. In conclusions, stenting with or without debulking atherectomy may be considered as an acceptable therapeutic option for the treatment of ostial LAD stenosis.