Clinical expert consensus document on rotational atherectomy from the Japanese association of cardiovascular intervention and therapeutics.

Rotational atherectomy (RA) has been widely used for percutaneous coronary intervention (PCI) to severely calcified lesions. As compared to other countries, RA in Japan has uniquely developed with the aid of greater usage of intravascular imaging devices such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT). IVUS has been used to understand the guidewire bias and to decide appropriate burr sizes during RA, whereas OCT can also provide the thickness of calcification. Owing to such abundant experiences, Japanese RA operators modified RA techniques and reported unique evidences regarding RA. The Task Force on Rotational Atherectomy of the J apanese Association of Cardiovascular Intervention and Therapeutics (CVIT) has now proposed the expert consensus document to summarize the contemporary techniques and evidences regarding RA.

In vivo tissue characterization of human atherosclerotic plaques by optical coherence tomography: A directional coronary atherectomy study with histopathologic confirmation.

BACKGROUND: The histopathological validation of optical coherence tomography (OCT) in visualizing atherosclerotic plaques has been reported only in ex vivo studies. We sought to evaluate the accuracy of OCT in tissue characterization in vivo. METHODS AND RESULTS: A total of 25 patients with stable angina pectoris who underwent directional coronary atherectomy (DCA) were included in the investigation, whereby OCT was performed before and after a single debulking. The debulked region was determined on OCT and classified into fibrous tissue, lipid, calcification, thrombus, and macrophage accumulation, which were compared with histology. Changes in OCT signal intensity in the deeper intimal region after DCA were also visually evaluated. Fibrous tissues were detected in all cases, while thrombus was identified only in 1 case, by both OCT and histology. The sensitivity, specificity, positive and negative predictive values, and predictive accuracy for lipid detection by OCT were 88.9%, 75.0%, 66.7%, 92.3%, and 80.0%; those for calcification were 50.0%, 100%, 100%, 91.3%, and 92.0%; and those for macrophage accumulation were 85.7%, 88.9%, 75.0%, 94.1%, and 88.0%, respectively. The false positive diagnoses for lipid were mostly attributed to the extracellular matrix accumulation containing less collagen. The false negative diagnoses for calcification were explained by the presence of lipid around the calcification. The OCT signal intensity in the deeper intimal region substantially increased after DCA in all cases. CONCLUSIONS: The current study showed excellent predictive accuracy of in vivo OCT in tissue characterization, whereas the limitations of OCT were highlighted by an over-detection of lipid, under-detection of calcification, and underestimation of the deeper intimal matrix.

European expert consensus on rotational atherectomy.

The interest in rotational atherectomy (RA) has increased over the past decade as a consequence of more complex and calcified coronary stenoses being attempted with percutaneous coronary interventions. Yet adoption of RA is hampered by several factors: amongst others, by the lack of a standardised protocol. This European expert consensus document stems from the awareness of the large heterogeneity in the protocols adopted to perform rotational atherectomy. The objective of the present document is to provide some points of consensus among highly experienced operators on the most controversial steps of RA in an attempt to build the basis of a standardised and universally accepted protocol.

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.

Guidewire bias in rotational atherectomy in the angled lesion: evaluation based on the thickness of the ablated intima and media.

The effect of guidewire bias on angled-lesion ablation by rotational atherectomy (RA) was assessed by measuring the changes in vertical lumen diameter, horizontal lumen diameter and the intima-media thickness of the coronary artery, using intravascular ultrasound in 10 lesions with an angle greater than 10 degrees. The vertical and horizontal diameters significantly increased after RA. The intima-media thickness at the 4 orthogonal sites significantly decreased. There was a significant positive correlation between vertical diameter change and angle (r=0.642, p=0.045), but none between horizontal diameter change and angle. There was no correlation between intima-media thickness change at 0 degrees and angle; however, at 180 degrees there was a tendency to correlation with angle (r=0.602, p=0.066). These data suggest that in cases of angled lesions, the increase in vertical lumen diameter is caused more by ablation of the 180 degrees wall than by that of the 0 degrees wall, which is brought about by guidewire bias toward the vascular wall at 180 degrees.

Safety and efficacy of percutaneous coronary interventions performed immediately after diagnostic catheterization in northern new england and comparison with similar procedures performed later.

"Ad hoc" percutaneous coronary interventions (PCIs)-those performed immediately after diagnostic catheterization-have been reported in earlier studies to be safe with a suggestion of higher risk in certain subgroups. Despite increasing use of this strategy, no data are available in recent years with new device technology. We studied use of an ad hoc strategy in a large regional population to determine its use and outcomes compared with staged procedures. A database from the 6 centers performing PCIs in northern New England and 1 center in Massachusetts was analyzed. During 1997, excluding only patients requiring emergency procedures or those with a prior PCI, 4,136 PCIs were performed, 1,748 (42.3%) of these being ad hoc procedures. Patients having ad hoc procedures were less likely to have peripheral vascular disease, renal failure, prior myocardial infarction, or coronary artery bypass surgery, congestive heart failure, or poor left ventricular function, and more likely to have received preprocedural intravenous heparin or nitroglycerin or to have required an urgent procedure. Narrowings treated during ad hoc procedures were less frequently types B and C or in saphenous vein grafts. Adjusted rates of clinical success were not different between ad hoc and non-ad hoc procedures (93.7% vs 93.6%); there was no difference in the incidence of death (0.6% vs 0.5%), emergency (0. 9% vs 0.8%) or any (1.4% vs 0.8%) coronary artery bypass surgery, or myocardial infarction (2.6% vs 2.0%). As currently practiced in our region, ad hoc intervention is used selectively with outcomes similar for ad hoc and non-ad hoc procedures.

[The practical clinical guidelines of the Sociedad Española de Cardiología on interventional cardiology: coronary angioplasty and other technics]. / Guías de práctica clínica de la Sociedad Española de Cardiología en cardiología intervencionista: angioplastia coronaria y otras técnicas.

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.

In vitro examination of the safety of rotational atherectomy of side branches jailed by stents.

In vitro experimental models of branch orifices jailed by various stents were created to estimate the safety and the efficacy of rotational atherectomy when rotational burrs were advanced through the struts of stents. The scaffolding structures of the stents were destroyed due to loss and deflection of the struts, and the size of ablated stent-particles differed: the maximal size was 1.7 mm in slotted stents, and 17.6 mm in coiled stents. Thus, there is a definite potential for ablating stents when rotational atherectomy of restenotic lesions of side-branch orifices jailed by stents is performed.

Benchmarking cardiac catheterization laboratories: the impact of patient age, gender and risk factors on variable costs, device costs, total time and procedural time in 53 catheterization laboratories.

Coronary catheterization laboratories (CCLs) are the cornerstones of the delivery system for many cardiovascular procedures performed in the United States. However, few comprehensive data exist benchmarking physician activities in CCLs. This study benchmarks cost and time data on 82,548 consecutive patient encounters in 53 CCLs for the 18-month period of January 1997 through June 1998. The data are compiled from the OEP program, a relational database developed by Boston Scientific/Scimed (Maple Grove, Minnesota) for use in CCLs. CCL productivity (total time and procedure time) and cost (variable costs and device costs) benchmarks are created for: 1) left heart catheterization; 2) right and left heart catheterization; 3) percutaneous transluminal coronary balloon angioplasty (PTCA); 4) atherectomy; and 5) coronary stents. Results show the variable costs (those costs that vary in direct proportion to changes in CCL activities) for the five procedures are: $308, left heart catheterization; $395, right and left heart catheterization; $841, PTCA; $2,768, atherectomy; and $3,186, coronary stent. These variable costs are lower than the typical average costs reported for these procedures because they do not include hospital, laboratory, and physician costs, only the procedure-specific activity-related costs most directly controlled and/or influenced by CCL physicians or administrators. The total time for the left heart catheterization averaged 64 minutes and 84 minutes for the right and left heart catheterization, respectively, and procedural times averaged 25 and 32 minutes, respectively. For the major interventional procedures N PTCA, atherectomy, and coronary stents, total times averages were 102, 135, and 117 minutes, respectively. Procedural times for these procedures averaged between 60 and 65 percent of the total time. The major implications of these findings are discussed and limitations noted.

Angioscopic evaluation of rotational atherectomy followed by additional balloon angioplasty versus balloon angioplasty alone in coronary artery disease: a prospective, randomized study.

OBJECTIVES: This study sought to compare, by angioscopy, the morphologic changes induced by rotational atherectomy, followed by additional angioplasty, with those observed after balloon angioplasty alone. BACKGROUND: Rotational atherectomy and balloon angioplasty act by different mechanisms, which could explain the difference in morphologic changes induced by these two techniques. METHODS: The study group included 50 patients with 50 lesions who were randomly assigned to undergo rotational atherectomy (n = 24) or balloon angioplasty (n = 26). Rotational atherectomy with a single burr (approximately equal to 70% of coronary diameter) was systematically followed by additional balloon angioplasty. Angioscopy was performed immediately after the procedure. Abnormal angioscopic findings were 1) flaps, graded from 1 to 3 (1 = intimal flap; 2 = flap protruding into < 50% of the lumen; 3 = flap protruding into > or = 50% of the lumen); 2) thrombi, graded from 1 to 3 (1 = flat deposits; 2 = protruding but nonocclusive thrombus; 3 = occlusive thrombus); 3) subintimal hemorrhage; 4) longitudinal dissection. The two groups were comparable for clinical and angiographic baseline data. RESULTS: On angioscopy, flaps were observed less frequently after rotational atherectomy followed by additional balloon angioplasty (8 [33%] of 24 lesions) than after balloon angioplasty alone (14 [54%] of 26 lesions, p = 0.08) and were also less severe (grade 1 in 6 lesions, grade 2 in 2 and grade 3 in none vs. grade 1 in 4 lesions, grade 2 in 5 and grade 3 in 5). Longitudinal dissections were also significantly less frequent: one versus six (p = 0.05). There was no difference in the incidence of angioscopic thrombi (p = 0.16) or subintimal hemorrhage (p = 0.15), but the power to detect a significant difference was low for these variables (37% and 26%, respectively). CONCLUSIONS: Rotational atherectomy followed by additional balloon angioplasty leads to fewer angioscopic dissections and a trend toward fewer intimal flaps than balloon angioplasty alone. However, our angioscopic differences did not lead to an outcome difference between the two groups.

[Rotational atherectomy: technique, indications, results]. / Rotablation: Technik, Indikation, Ergebnisse.

Rotational atherectomy (Rotablation) represents one of the alternative devices to treat complex coronary artery stenoses. Rather than increasing luminal diameter by arterial stretching and plaque fracture as with balloon angioplasty, rotablation debulks atherosclerotic plaque with an abrasive diamond coated burr. The basic physical principle is differential cutting. It allows the advancing burr to selectively cut inelastic material while elastic tissue deflects away from the burr. 95% of the particles generated by the Rotablator are less than 5 microns. They are removed by the body's reticuloendothelial system. There are different strategies to perform a rotablation, regarding the number of burrs used and the final burr-to-artery ratio. An adjunctive PTCA is recommended without proof by randomized studies so far. The best indication for the Rotablator is the undilatable lesion. Lesion modification (debulking) as a method of improving vessel compliance seems to be also usefull in diffusely diseased and calcified vessels, as well as in aorto-ostial and angulated stenoses. The instent restenoses is a new indication. Randomized studies will have to proof if there is an advantage for rotablation compared to PTCA. Restenosis rates appear comparable to balloon angioplasty.

Observational versus randomized medical device testing before and after market approval--the atherectomy-versus-angioplasty controversy.

Percutaneous transluminal coronary angioplasty was developed in the late 1970s as a nonsurgical alternative for revascularization of atherosclerotic coronary arteries. It gained widespread acceptance without a controlled trial. Introduced in 1986, directional coronary atherectomy was the first of other recently developed coronary devices that sought to improve on the results of angioplasty. It was approved in 1990 by the Food and Drug Administration (FDA) on the basis of observational data. Its use expanded rapidly, reaching over 35,000 procedures in 1992, accounting for more than 10% of all interventions. After premarket approval, two major randomized trials tested the hypothesis that atherectomy would be superior to angioplasty. Their results raised a cautionary flag and stood in contrast to projections made from prior observational data. It is concluded that randomized controlled trials validate claims of relative efficacy and safety of competing medical technologies, a lesson reflected in recent changes in policy at the FDA.

Directional atherectomy for treatment of restenosis within coronary stents: clinical, angiographic and histologic results.

OBJECTIVES: The safety and long-term results of directional coronary atherectomy in stented coronary arteries were determined. In addition, tissue studies were performed to characterize the development of restenosis. METHODS: Directional coronary atherectomy was performed in restenosed stents in nine patients (10 procedures) 82 to 1,179 days after stenting. The tissue was assessed for histologic features of restenosis, smooth muscle cell phenotype, markers of cell proliferation and cell density. A control (no stenting) group consisted of 13 patients treated with directional coronary atherectomy for restenosis 14 to 597 days after coronary angioplasty, directional coronary atherectomy or laser intervention. RESULTS: Directional coronary atherectomy procedures within the stent were technically successful with results similar to those of the initial stenting procedure (2.31 +/- 0.38 vs. 2.44 +/- 0.35 mm). Of five patients with angiographic follow-up, three had restenosis requiring reintervention (surgery in two and repeat atherectomy followed by laser angioplasty in one). Intimal hyperplasia was identified in 80% of specimens after stenting and in 77% after coronary angioplasty or atherectomy. In three patients with stenting, 70% to 76% of the intimal cells showed morphologic features of a contractile phenotype by electron microscopy 47 to 185 days after coronary intervention. Evidence of ongoing proliferation (proliferating cell nuclear antigen antibody studies) was absent in all specimens studied. Although wide individual variability was present in the maximal cell density of the intimal hyperplasia, there was a trend toward a reduction in cell density over time. CONCLUSIONS: Although atherectomy is feasible for the treatment of restenosis in stented coronary arteries and initial results are excellent, recurrence of restenosis is common. Intimal hyperplasia is a nonspecific response to injury regardless of the device used and accounts for about 80% of cases of restenosis. Smooth muscle cell proliferation and phenotypic modulation toward a contractile phenotype are early events and largely completed by the time of clinical presentation of restenosis. Restenotic lesions may be predominantly cellular, matrix or a combination at a particular time after a coronary procedure.