Cost-effectiveness of fluvastatin following successful first percutaneous coronary intervention

BACKGROUND

In the LIPS (Lescol Intervention Prevention Study), fluvastatin 80 mg/day reduced the risk of major adverse cardiac events (MACE) by 22% versus placebo (p = 0.01) following successful first percutaneous coronary intervention (PCI) in patients with stable or unstable angina or silent ischemia. The cost-effectiveness of such therapy is unknown.

OBJECTIVE

To evaluate the cost-effectiveness of fluvastatin following successful first PCI from a US healthcare system perspective.

METHODS

We used a Markov model to estimate expected outcomes and costs of 2 alternative treatment strategies following successful first PCI in patients with stable or unstable angina or silent ischemia: (1) diet/lifestyle counseling plus immediate fluvastatin 80 mg/day; and (2) diet/lifestyle counseling only, with initiation of fluvastatin 80 mg/day following occurrence of future nonfatal MACE. The model was estimated with data from LIPS and other published sources. Cost-effectiveness was calculated as the ratio of the difference in expected medical-care costs to the expected difference in life-years (LYs) and quality-adjusted life-years (QALYs) alternatively.

RESULTS

Treatment with fluvastatin following successful first PCI was found to increase life expectancy by 0.78 years (QALYs 0.68). Cost-effectiveness of fluvastatin following successful first PCI is 13 505 dollars per LY (15 454 dollar per QALY) saved. Ratios are lower for patients with diabetes (9396 dollar per LY; 10 718 dollar per QALY) and those with multivessel disease (9662 dollar per LY; 11 076 dollar per QALY). Findings were robust with respect to changes in key model parameters and assumptions.

CONCLUSIONS

Fluvastatin therapy following PCI is cost-effective compared with other generally accepted medical interventions.

Exploration of a bayesian updating methodology to monitor the safety of interventional cardiovascular procedures

Appropriate methods for monitoring of the safety of medical devices introduced into clinical practice have been elusive to develop and implement. A novel approach is the application of Bayesian updating, which incorporates existing knowledge regarding event rates into the estimation of risk. This framework has been shown in other domains to be data efficient and to address some of the limitations of conventional statistical methods. In this article, the authors propose a methodologic framework for developing initial prior probability distributions in risk-stratified patient groups and a mechanism for incorporating accumulating procedure safety experience. In addition, they use this methodology to retrospectively analyze the clinical outcomes of 309 patients undergoing an infrequent interventional cardiology procedure, rotational atherectomy. These exploratory analyses demonstrate the feasibility of Bayesian updating applied to medical device safety evaluation and indicate that the methodology is capable of generating stable estimates of risk in a variety of patient risk groups.

A contemporary overview of percutaneous coronary interventions. The American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR)

The American College of Cardiology (ACC) established the National Cardiovascular Data Registry (ACC-NCDR) to provide a uniform and comprehensive database for analysis of cardiovascular procedures across the country. The initial focus has been the high-volume, high-profile procedures of diagnostic cardiac catheterization and percutaneous coronary intervention (PCI). Several large-scale multicenter efforts have evaluated diagnostic catheterization and PCI, but these have been limited by lack of standard definitions and relatively nonuniform data collection and reporting methods. Both clinical and procedural data, and adverse events occurring up to hospital discharge, were collected and reported according to uniform guidelines using a standard set of 143 data elements. Datasets were transmitted quarterly to a central facility for quality-control screening, storage and analysis. This report is based on PCI data collected from January 1, 1998, through September 30, 2000.A total of 139 hospitals submitted data on 146,907 PCI procedures. Of these, 32% (46,615 procedures) were excluded because data did not pass quality-control screening. The remaining 100,292 procedures (68%) were included in the analysis set. Average age was 64 +/- 12 years; 34% were women, 26% had diabetes mellitus, 29% had histories of prior myocardial infarction (MI), 32% had prior PCI and 19% had prior coronary bypass surgery. In 10% the indication for PCI was acute MI < or =6 h from onset, while in 52% it was class II to IV or unstable angina. Only 5% of procedures did not have a class I indication by ACC criteria, but this varied by hospital from a low of 0 to a high of 38%. A coronary stent was placed in 77% of procedures, but this varied by hospital from a low of 0 to a high of 97%. The frequencies of in-hospital Q-wave MI, coronary artery bypass graft surgery and death were 0.4%, 1.9% and 1.4%, respectively. Mortality varied by hospital from a low of 0 to a high of 4.2%. This report presents the first data collected and analyzed by the ACC-NCDR. It portrays a contemporary overview of coronary interventional practices and outcomes, using uniform data collection and reporting standards. These data reconfirm overall acceptable results that are consistent with other reported data, but also confirm large variations between individual institutions.

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.

Evolving trends in interventional device use and outcomes: results from the National Cardiovascular Network Database

BACKGROUND

Although multiple new coronary interventional devices have been approved for marketing in the United States, use of these technologies in general clinical practice and their associated outcomes have not been reported.

METHODS AND RESULTS

Using the National Cardiovascular Network's Coronary Interventional Database, we examined temporal trends in the use and outcomes of coronary stents, lasers, directional atherectomy, and rotational atherectomy devices at 12 US hospitals between January 1994 and December 1997 (n = 76,904). Over this period, the percentage of cases involving coronary stents rose more than 12-fold (from 5.4% in 1994 to 69.0% in 1997). In contrast, use of atherectomy-type devices declined significantly. Device selection was strongly influenced by the patient's coronary anatomy and procedural indication, but less by age, sex, or race. Device use also varied significantly among individual centers (4-fold variation among sites in stent use and 6-fold variation in atherectomy use) even after adjusting for patient characteristics. Although overall mortality rates were unchanged during this 4-year period, procedural success rates have improved and complication rates have declined significantly. Lengths of postprocedure hospital stay also fell significantly for all patients undergoing coronary intervention in this time period.

CONCLUSIONS

Percutaneous interventional strategies are rapidly changing with the explosive growth of coronary stent use and the decline in use of atherectomy devices. Patient outcomes, including complication rates and postprocedure lengths of stay, have also improved as the new interventional strategies have been refined in clinical practice.

Contemporary trends in coronary intervention: a report from the Registry of the Society for Cardiac Angiography and Interventions

This report of the Registry for the Society for Cardiac Angiography and Interventions provides data on the trends in coronary interventional procedures from the time period June 1966 through December 1998. A total of 19,510 consecutive coronary interventional procedures were recorded. Over this time period, significant trends in coronary stent implantation were recorded along with a decreasing reliance on balloon angioplasty as sole therapy. Patients with acute myocardial infarction comprised an increased fraction of all procedures. Almost half of all interventions were performed in patients with multivessel disease. Finally, decreasing rates of in-hospital death and emergent bypass surgery compared to prior reports from the registry characterize the current practice of interventional cardiology. Cathet. Cardiovasc. Intervent. 49:19-22, 2000.

Influence of a randomized clinical trial on practice by participating investigators: lessons from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT). CAVEAT I and II Investigators

OBJECTIVES

We sought to determine whether the results of the first Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) influenced subsequent practice patterns among the investigators.

BACKGROUND

CAVEAT-I demonstrated that directional coronary atherectomy (DCA) resulted in higher rates of early complications at a higher cost and with no clinical benefit. We sought to determine whether these results influenced subsequent use of procedures among CAVEAT-I investigators.

METHODS

We compared the results of a week-long registry of all coronary interventions performed at 35 CAVEAT-I sites in 1994 with those of a similar registry obtained in 1992 before the trial, the results of which were published in 1993. For control purposes, the use of procedures was studied at 24 additional sites to provide insight into practice at hospitals not participating in the trial. A total of 1,465 interventions were analyzed.

RESULTS

Ninety-four percent of CAVEAT-I sites responded. Utilization rates differed between CAVEAT-I and CAVEAT-I follow-up (p < 0.001). Balloon angioplasty decreased from 83.8% to 68.5%, DCA increased slightly from 10.7% to 14.1%, and the use of other devices increased from 5.4% to 17.5%. Stand-alone balloon use was more prevalent at nonparticipating control sites than at sites that took part in CAVEAT-I (p < 0.001).

CONCLUSIONS

Paradoxically, despite the negative findings of CAVEAT-I, there was a noteworthy trend toward an increase in the use of DCA and other devices at CAVEAT-I sites. Our findings suggest that among investigators in the trial, there may have been a lack of influence of trial data on clinical practice patterns 1 year after publication of the results. Ethics of protocol: Both CAVEAT I and II were approved by the Institutional Review Board at each study site.

High-speed rotational atherectomy of human coronary stenoses: acute and one-year outcomes from the New Approaches to Coronary Intervention (NACI) registry

High-speed rotational atherectomy (RA) is a new percutaneous procedure for treatment of coronary stenoses that operates by the unique mechanism of plaque abrasion. This article reports acute (in-hospital) outcomes and 1-year follow-up in a large cohort of patients treated with this device by NACI investigators. A total of 525 patients with 670 lesions treated with RA form the substrate of this report. Patients tended to be older (mean age 64.8 years) than those in previously reported series of percutaneous transluminal coronary angioplasty (PTCA), with more extensive disease and more complex lesions. Calcification was present in 54% of lesions, and eccentricity in 41%. Balloon angioplasty postdilation was performed after RA in 88% of cases. Angiographic and procedural success (angiographic success without death, Q-wave myocardial infarction [MI] or emergency coronary artery bypass graft [CABG] surgery) rates were 89% and 88%, respectively. Acute in-hospital events included 4 deaths (1%) and 1 emergency CABG surgery (0.4%). MI occurred in 6% of patients, consisting predominantly of non-Q-wave MI (5%). After RA, angiographic complications included coronary dissection (12%), abrupt closure (5%), side branch occlusion (3%), and distal embolization (3%). Most of these were resolved after postdilation except for coronary dissection, which was present in 15% of lesions treated. Mean length of stay was 3 days. At 1-year follow-up, 27% of patients required target lesion revascularization and 30% had experienced death, Q-wave MI, or target lesion revascularization. Preprocedural characteristics that independently predicted 1-year death, Q-wave MI, or target lesion revascularization were male gender, high risk for surgery, target lesions that were proximal to or in bifurcations, eccentric, long, or highly stenosed. RA, even when applied to lesions of traditionally unfavorable morphology, appears to provide reasonable procedural and angiographic success rates. Restenosis and progression of disease contribute to subsequent clinical and procedural events.

Directional coronary atherectomy (DCA): a report from the New Approaches to Coronary Intervention (NACI) registry

Directional coronary atherectomy (DCA) with the Simpson coronary atherocath seeks to debulk rather than simply displace obstructive tissue and is a means of enlarging the stenotic coronary lumen. This report from the New Approaches to Coronary Intervention (NACI) registry describes the experience of 1,196 patients who underwent DCA as the sole treatment for either native vessel or vein graft lesions. Device success (post-DCA residual stenosis <50% and > or =20% improvement) was achieved in 87.8%, with a lesion success rate (postprocedural residual stenosis <50% and > or =20% improvement) of 94.0%. The mean resultant stenosis after all interventions (by core laboratory) was 19%. Significant in-hospital complications occurred in 2.8% of patients with DCA attempts, including death 0.6%, Q-wave myocardial infarction (MI) 1.5%, and emergent coronary artery bypass graft surgery (CABG) 2.8%. At 1-year follow-up, cumulative mortality was 3.6%, with repeat revascularization in 28% (repeat percutaneous transluminal coronary angioplasty, 20.1%; CABG, 10.6%). This reflected percutaneous or surgical revascularization of the original lesion (target lesion revascularization) in 22.6% of patients. Subgroup analysis showed a lower lesion success rate and an increased complication rate for unplanned use, vein graft treatment, and treatment of a de novo (vs a restenotic) lesion. Multivariate analysis shows that diabetes mellitus, unstable angina, treatment of a restenotic lesion, and greater residual stenosis after the initial procedure were independent predictors of the composite endpoint of death/Q-wave MI/target lesion revascularization by 1-year follow-up. Among these generally favorable acute and 1-year results, the NACI directional atherectomy data confirm the "bigger is better" hypothesis: that lesions with a lower residual stenosis after a successful procedure had significantly fewer target lesion revascularizations between 30 days and 1 year, with no increase in major adverse events.

Transcatheter coronary revascularization registry 1995

In 1995, from 12 participating units, there were 1108 PTCA compared to 697 in 1994, 24 rotational atherectomy and 109 intracoronary stent placements performed. These were complicated by 6 acute myocardial infarction, 10 emergency surgeries and 11 deaths. Success rate was 92 per cent. Indication for transcatheter revascularization were stable angina pectoris in 60 per cent of cases, unstable angina in 18 per cent and post infarct angina in 16 per cent. Thirty cases were done in AMI setting. Of those 1108 vessels approached, 1297 lesions were in native arteries and 9 were in saphenous vein grafts. Most lesions were in AHA/ACC type B category. One hundred and fourteen stents were placed in 109 patients in 1995. Seven stents emboli occurred in addition to one myocardial infarction, 2 CABG, 2 death and 2 major bleeding. Transcutaneous coronary revascularization has increased in number with acceptable results. Coronary stenting was done in an average of 10 per cent of all procedures and also with reasonable complication rates.

[Local progression of atherosclerosis after optimal directional atherectomy. Endocoronary ultrasonography of 17 patients]

In vivo endovascular ultrasonography has confirmed the extension of atheroma to angiographically normal segments. The authors set out to determine by endocoronary ultrasonography if the introduction of the atherotome changed the intimal thickness 20 mm proximal and distal to the site treated. The area circumscribed by the external elastic layer (EEL) and the surface area of the lumen was measured in 17 patients: 1) before atherectomy; 2) after atherectomy; 3) at control 6 months later. Atherectomy immediately increased the luminal area at the site dilated from 1.9 + 0.9 to 8.1 +/- 2mm (p < 0.001). At the proximal segment, the surface area of the lumen was unchanged (mean + 0.6 +/- 1.5 mm2; p = 0.13). Similarly the procedure did not change the surface circumscribed by the EEL (mean + 0.8 +/- 3.2 mm2; p = 0.32) in this zone. The same results were observed at the distal site. At 6 months, the areas under the EEL and those of the lumen were unchanged at the unoperated sites. The mean of the differences (+/- 1 SD) for the area under the EEL was respectively -0.2 +/- 1.5 mm2 proximally and +0.7 +/- 2.5 mm2 distally. The means for the luminal area were 0.2 +/- 1 mm2 proximally and -0.01 +/- 1.1 mm2; distally. At the site of atherectomy, the luminal surface increased (+2.0 +/- 2.6 mm2; p < 0.01) as did the area under the EEL (+2.0 +/- 3.5 mm2; p < 0.05). This preliminary series shows no significant progression of atherosclerosis at the sites not affected by atherectomy.

The changing face of coronary interventional practice. The Mayo Clinic experience

BACKGROUND

Devices designed to facilitate or replace conventional percutaneous transluminal coronary angioplasty have been introduced in recent years.

OBJECTIVES

To characterize the changes in percutaneous coronary interventional practice over 16 years and to assess the relative use of these new devices.

METHODS

We performed a retrospective analysis of all patients who underwent percutaneous coronary revascularization at Mayo Clinic, Rochester, Minn, during a 16-year period (1980-1995) and characterized the changes in procedural and clinical factors.

RESULTS

The number of coronary interventional procedures performed increased from 38 in 1980 to 1284 in 1995. Atherectomy and laser angioplasty were incorporated in 1988; their use peaked in 1994 (17% of procedures) but decreased to 9.9% by 1995. In contrast, the use of intracoronary stents has increased steadily since 1990. By 1995, intracoronary stents were placed in 48.2% of procedures. The success rate improved from 55.3% in 1980 to 91.4% in 1995, although patients were older (51 +/- 10 [mean +/- SD] years in 1980 vs 63 +/- 12 years in 1995), had more extensive coronary artery disease (0% with multivessel disease in 1980 vs 47.4% in 1995), had more complex lesions, and often underwent intervention in the peri-infarction setting (2.6% of procedures in 1980 vs 17% in 1995). The rate of referral to emergency coronary bypass surgery after percutaneous procedures declined from 5.2% in 1980 to 0.4% in 1995.

CONCLUSIONS

Current coronary interventional practice is expanding and improving. In contrast to intracoronary stents that have greatly affected current practice, other new devices are used infrequently. Conventional angioplasty, with or without intracoronary stents, remains the dominant treatment strategy.

Transluminal extraction atherectomy for restenosis following Palmaz-Schatz stent implantation

Transluminal extraction atherectomy with adjunctive balloon angioplasty was successfully performed in 9 patients who had restenosis after Palmaz-Schatz stent implantation. Although 4 patients with either totally occluded lesions or with saphenous vein graft lesions had recurrence, this strategy may be a potential treatment for in-stent restenosis.

Impact of diabetes mellitus on percutaneous revascularization (CAVEAT-I). CAVEAT-I Investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial

We examined the relation between diabetes mellitus and outcomes in patients undergoing percutaneous coronary revascularization in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), a randomized trial comparing treatment with either percutaneous transluminal coronary angioplasty or directional atherectomy for de novo lesions in native coronary arteries. Acute success and complication rates, 6-month angiographic restenosis rates, and 1-year clinical outcomes were compared between diabetic and nondiabetic patients undergoing each procedure. Acute success rates between diabetic (n = 191) and nondiabetic (n = 821) patients were similar for both revascularization techniques. Except for the need for dialysis, complication rates were also similar. Six months after atherectomy, diabetic patients had significantly more angiographic restenosis than nondiabetics (59.7% vs 47.4%) and significantly smaller minimum luminal diameters (1.20 vs 1.40 mm). Diabetics undergoing atherectomy required more frequent bypass surgery (12.8% vs 8.5%) and more repeat percutaneous revascularizations (36.5% vs 28.1%) than nondiabetics undergoing atherectomy. Restenosis rates, minimum luminal diameters and repeat revascularizations between diabetics and nondiabetics undergoing angioplasty were similar. The higher restenosis and repeat revascularization rates and the smaller minimum luminal diameter at follow-up in diabetic patients suggest that atherectomy may provide only modest benefit for these patients. The increased restenosis rate in diabetics undergoing atherectomy (but not angioplasty) requires further evaluation.

Effect of rotational atherectomy on quality of life

OBJECTIVE

To evaluate whether percutaneous coronary rotational atherectomy (RA) improves quality of life.

DESIGN

Prospective sequential study of the first 20 patients who had RA at St Paul's Hospital, Vancouver from November 1993 to April 1994.

SETTING

Tertiary care teaching hospital.

PATIENTS

There were nine males and 11 females with a mean age of 68 +/- 9.3 years. All had angina pectoris with type B or C coronary lesions.

INTERVENTIONS

RA was performed using the Rotablator device.

RESULTS

The procedure was angiographically successful in 20 patients and clinically successful in 18 patients. Two patients who sustained acute myocardial infarctions underwent coronary bypass surgery. Before RA there was one patient in Canadian Cardiovascular Society angina class I, five patients in class II, 12 in class III, and two in class IV. At six months' follow-up there were 11 patients in class I, seven in class II and two in class III. The mean Duke Activity Status Index improved from 21.3 +/- 15.8 (mean +/- SD) before the procedure to 36.9 +/- 15.8 (P < 0.001) at six months' follow-up. The consumption of anti-anginal medications also decreased.

CONCLUSIONS

RA was associated with improved functional status and quality of life in patients having angina pectoris with type B or C coronary lesions.

Rotational coronary atherectomy with adjunctive balloon angioplasty: evaluation of lumen enlargement by quantitative angiographic analysis

To evaluate the mechanisms of lumen enlargement and the respective contributions of rotational coronary atherectomy (RA) and adjunctive percutaneous transluminal coronary balloon angioplasty (PTCA), serial measurements were recorded in 70 consecutive patients by quantitative coronary angiography before RA, after RA, after adjunctive PTCA, and 24 hours later. Minimal luminal diameter (MLD) increased from 0.85 +/- 0.31 mm to 1.42 +/- 0.27 mm (p < 0.001) after RA and to 2.20 +/- 0.46 mm (p < 0.001) after PTCA. Minimal luminal area (MLA) increased from 0.64 +/- 0.50 mm2 to 1.63 +/- 0.60 mm2 (p < 0.001) after RA and to 3.97 +/- 1.68 mm2 (p < 0.001) after PTCA. Both 24-hour MLD and MLA showed a trend toward reduced values (2.07 +/- 0.45 mm and 3.52 +/- 1.70 mm2, respectively) when compared with immediate results after PTCA. The absolute gains in MLD after RA and after PTCA were 0.56 +/- 0.24 mm and 0.79 +/- 0.38 mm, respectively (p < 0.01). The absolute gains in MLA after RA and after PTCA were 0.99 +/- 0.49 mm2 and 2.34 +/- 1.41 mm2, respectively (p < 0.001). The respective contributions of RA and PTCA are highly variable, but in general, balloon dilatation accounts for most of the gain in lumen area and therefore is not an adjunctive but a primary technique.

Angiographic predictors of neointimal thickening after successful coronary wall healing following percutaneous revascularization

This study was undertaken to characterize, by intracoronary ultrasound technique, the neointimal thickening at follow-up of treated coronary segments after successful arterial wall repair and to compare the findings with serial angiographic studies. We selected for study 81 patients with single-vessel coronary disease successfully treated by percutaneous revascularization who were angiographically and ultrasonically reevaluated at a mean follow-up time of 22 +/- 21 months; 23 had been treated by balloon angioplasty, 27 by directional atherectomy, and 31 by elective Palmaz-Schatz stent implantation. The late maximal neointimal thickness varied between 0.1 and 1.5 mm (mean 0.65 +/- 0.31 mm), and the neointimal area ranged between 0.97 and 14.9 mm2 (mean 5.19 +/- 3.14 mm2). The neointimal repair was thinner in patients who obtained a better acute angiographic result immediately after treatment and in stented (3.4 +/- 1.8 mm2) versus dilated (7.8 +/- 4.1 mm2) or resected (5 +/- 1.6 mm2, p < 0.001) segments. On the contrary, the repaired neointimal layer was thicker in those patients who angiographically exhibited less late luminal loss or even expansion and in those evaluated after a longer time since treatment. The acute gain and the time influence resulted in independent predictors of the degree of neointimal thickness. These findings suggest that two reparative mechanisms of the coronary wall may operate in close relation.

[Quality assurance in invasive and interventional cardiology in Austria in 1994. Commissioned by the Interventional Cardiology Working Group of the Austrian Cardiology Society]

A complete National Database is the prerequisite for quality control, quality management and improvement. In Austria, we have been reaching for this goal since more than three years. 21 094 diagnostic coronary angiographies (CA) and 4934 PTCAs were performed in all 27 centers (out of which 17 perform PTCA) in Austria during the year 1994. This is a reduction of 3.2% concerning CA and an 8.6% increase in PTCA compared to 1993. 48% of all PTCAs were done during the diagnostic study (CA), multivessel PTCA in 11%, direct PTCA for ongoing infarction in 2.3%. Concerning "new devices", 437 stents (182 during the year 1993) were implanted in 1994; also all 73 cases with rotablator, 105 with intracoronary ultrasound, and 26 directional coronary atherectomies (DCA) are documented. Hospital mortality after PTCA was 0.5% (unchanged from the years 1992 and 1993), emergency bypass surgery rate after PTCA was 1.2% (0.7% during the year 1993), and 1.4% of the patients suffered a myocardial infarction in the cathlab (1.2% during 1993). International comparison shows Austria among the top nations with 2637 CA and 617 PTCA per million inhabitants, corresponding to a ratio of 23% PTCA per 100 CA. Risk adjustment (exercise stress test pre PTCA documented in six cath-labs in 1993, compared to 11 in 1994. Type of stenosis (A, B, C) in five labs in 1993 and in 12 labs in 1994) and outcome control (exercise stress test 3 months after PTCA documented in five cath-labs in 1993, compared to 10 in 1994) are subject to constant improvement of our yearly monitor visits and feedback reaction. Austria is the only nation worldwide to support a complete national database with controlled numbers and parameters since more than 3 years, including yearly monitor visits (Internet address for the 1995 data: http@info.uibk.ac.at/gin/org/i_iik.stu/i_iik+ ++.htm) and feedback reports. We experienced no single negative reaction to our activities, but find them necessary for further quality management targets.

Are there gender differences or issues related to angiographic imaging of the coronary arteries?

The use of coronary angiography and coronary interventions in women with suspected coronary artery disease has recently come under close scrutiny. Clear differences in the utilization of these procedures, including coronary artery bypass graft (CABG) surgery have led to concerns that a bias may exist against the use of these procedures in women. Alternative explanations of these perceived practice differences have focused on their propriety based on patients' ages, underlying disease severity, expected prevalence of coronary disease and comorbid conditions rather than physician bias. The possibility that these procedures are over utilized in men has also been suggested. Pertinent to this debate are historical observational data suggesting that women may be at higher risk of major complications of coronary interventions and CABG surgery. Because coronary artery disease is the most frequent cause of death among women in the United States, there is some sociopolitical urgency in addressing these important concerns. This article reviews the use and findings of diagnostic coronary angiography in women with suspected coronary artery disease. Specific risks to women who have coronary angiography performed are also discussed. Finally, the outcome of percutaneous coronary revascularization procedures in women compared to men is discussed.

High speed rotational atherectomy: outcome in calcified and noncalcified coronary artery lesions

OBJECTIVES

This study sought to determine the success and complication rates of high speed rotational coronary atherectomy in calcified and noncalcified lesions.

BACKGROUND

Percutaneous transluminal coronary angioplasty and directional coronary atherectomy of calcified lesions are associated with reduced procedural success and increased complications. Rotational atherectomy using the Rotablator catheter abrades noncompliant plaque and may improve outcome in calcified lesions.

METHODS

Data from the completed Multicenter Rotablator Registry of 2,161 rotational atherectomy procedures in single lesions were analyzed to determine the relative efficacy of rotational atherectomy for 1,078 calcified and 1,083 noncalcified lesions. The power of the study was 0.86 to detect a significant difference in outcome, if the true success rates in the noncalcified and calcified lesions were 96% and 93%, respectively.

RESULTS

Patients with calcified lesions were older (mean [+/- SD] age 66.2 +/- 10.3 vs. 60.5 +/- 11.0 years, p = 0.0001) than those with noncalcified lesions. Calcified lesions were more frequently new (75% vs. 64%, p = 0.0001), angulated (27% vs. 22%, p = 0.02), eccentric (75% vs. 64%, p = 0.0001) and long (32% vs. 27%, > 10 mm in length, p = 0.01). They were also more often complex (57% vs. 46%, p = 0.001) and located in the left anterior descending coronary artery (51% vs. 44%, p = 0.001). Adjunctive coronary angioplasty was used in 82.9% of calcified and 66.9% of noncalcified lesions. Procedural success, defined as < 50% residual stenosis without major complications, was achieved in 94.3% of calcified and 95.2% of noncalcified lesions (p = 0.32). Major complication rates were 4.1% in calcified and 3.1% in noncalcified lesions (p = 0.24). Non-Q wave myocardial infarction was documented in 10.0% of calcified and 7.7% of noncalcified lesions (p = 0.054). Mean postprocedural residual stenosis was 21.6 +/- 13.9% in calcified and 23.3 +/- 15% in noncalcified lesions (p = 0.39).

CONCLUSIONS

In this review of data from a large multicenter registry, the success rate of rotational atherectomy was not reduced by calcification despite the more frequent complex nature of the calcified lesions. The Rotablator catheter is likely to be the device of choice for percutaneous intervention in calcified lesions, but definitive conclusions await the results of randomized trials.

Coronary interventions in Europe 1992. The Working Group on Coronary Circulation of the European Society of Cardiology

The general practice of coronary interventions is influenced by various aspects, traditional, cultural, socioeconomic and personal. The aim of this survey was to collect the data on coronary intervention in all member countries of the European Society of Cardiology. The data from 12 of the 35 national members were missing or grossly incomplete and were therefore excluded from the analysis.

CORONARY ANGIOGRAPHY

The total number of coronary angiograms was reported as 683,888, an incidence of 1009 +/- 1021 per million inhabitants (range 9 (Romania) to 3076 (Germany)). Germany (246,115 cases), France (144,754), the United Kingdom (76,296), Italy (45,517) and Spain (43,495) registered 81% of all the coronary angiograms performed.

PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

(PTCA) The total number of reported PTCAs was 147,729, which on average accounted for 19 +/- 11% (range 2 (Lithuania) to 53% (Netherlands)) of the coronary angiograms. Most of the PTCAs (82%) were confined to a single vessel. The highest incidence of multivessel PTCA was reported from Slovakia (28%). PTCA took place immediately after the diagnostic study in only 18% of cases. Adjusted per capita, Germany ranked first with 703 PTCAs per million inhabitants, followed by Iceland (619), France (614), Belgium (568) and Austria (485). A major in-hospital complication was reported in 2.5% of the patients undergoing PTCA: 0.4% hospital deaths, 1.0% emergency CABGs and 1.1% myocardial infarctions.

NEW DEVICES

Stents were implanted in 3211 patients (2.7% of all PTCA patients), equally distributed between emergency situations (53%) and elective procedures. Other interventional devices were applied in 4133 cases (2.8% of all PTCA cases): directional atherectomy, rotablator, transluminal extraction catheter, laser and Rotacs accounted for 1452, 1232, 55, 558 and 222, respectively. Coronary ultrasound (1350 cases) and coronary angioscopy (373 cases) were rarely performed.

CORONARY ARTERY BYPASS GRAFTING (CABG)

A total of 63,477 patients underwent CABG in the reporting centres resulting in a PTCA/CABG ratio of 2.3. A significant under-reporting of surgery in the participating centres must be assumed.

CONCLUSIONS

Although partial reporting might bias conclusions, several findings of this survey are noteworthy: (1) PTCA was a well accepted treatment for coronary artery disease, (2) PTCA was applied more frequently than CABG, (3) there was an extremely wide range of coronary angiography and PTCA performed per million inhabitants, (4) the most common additional procedure was stent implantation, but other new devices were only rarely applied.

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.

Intracoronary ultrasound imaging before and after directional coronary atherectomy: in vitro and clinical observations

The rate of restenosis after directional coronary atherectomy (DCA) is higher than expected. To elucidate why, the current study used intravascular ultrasound (IVUS) imaging to investigate the mechanism of DCA. An in vitro validation study was performed to determine the accuracy of the measurement of plaque removal by IVUS. DCA was performed in eight human atherosclerotic artery segments. The volume of removed plaque was measured by water displacement and was compared with the volume calculated from IVUS images. A clinical study of DCA was performed in 32 lesions. IVUS was performed in 28 lesions after successful DCA. Measurements of lumen dimensions from digital angiograms before and after DCA were compared with observations of lumen and plaque size from the cross-sectional IVUS images. In the in vitro study, the mean plaque volume removed by DCA was 19.9 +/- 8.5 microliters. The calculated estimate of removed plaque volume by IVUS was 18.6 +/- 7.9 microliters and correlated closely with the volume by water displacement (r = 0.92). The calculated volume of plaque removed from histologic sections was 14.3 +/- 6.0 microliters and was linearly correlated with plaque volume by water displacement (r = 0.81). In the clinical study, the angiographic mean minimum lumen diameter increased from 1.0 +/- 0.4 to 2.7 +/- 0.5 mm and the percentage stenosis decreased from 70% to 19% (p < 0.0001). The IVUS images before and after DCA showed that the lumen DCA improved from 2.9 +/- 1.5 to 7.0 +/- 1.5 mm2 (p < 0.0001). In addition the vessel cross-sectional area (CSA) increased from 17.1 +/- 5.9 to 18.7 +/- 5.5 mm2. The atheroma CSA was reduced from 14.2 +/- 5.0 to 11.7 +/- 4.8 mm2. This combined effect of reduction in atheroma CSA and stretching of the outer vessel diameter resulted in an improvement in percentage plaque area stenosis from 83% +/- 7% to 61% +/- 9%. It is concluded that despite a successful angiographic appearance, DCA removed an average of 2.5 mm2 from the atheroma, which corresponds to only 18% of the atheroma CSA. The total lumen CSA increased 4.1 mm2; 61% of the new lumen was created by cutting and removal of plaque, whereas 39% of the new lumen was made by stretching the external wall of the artery. Despite an excellent angiographic result, IVUS imaging reveals that after DCA a significant amount of residual atheroma remains. As in balloon dilatation, a stretching effect is a significant component of DCA.

Features and outcome of no-reflow after percutaneous coronary intervention

No-reflow is an uncommon complication that may occur after revascularization of patients with acute myocardial infarction, after interventions in saphenous vein bypass grafts, and after the use of some new interventional devices. However, the clinical impact of no-reflow after coronary intervention is unknown. Accordingly, this study examined the incidence, clinical presentation, angiographic characteristics, and outcome of no-reflow after percutaneous coronary intervention. No-reflow was defined as an acute reduction in antegrade flow (< or = 1, as defined by the Thrombolysis in Myocardial Infarction [TIMI] trial) not attributable to abrupt closure, high-grade stenosis, or spasm of the original target lesion. Among 10,676 coronary interventions performed between October 1988 and June 1993, no-reflow occurred in 66 patients (0.6%). These patients were compared with a subgroup of 500 consecutive patients who did not exhibit no-reflow. The incidence of no-reflow was 30 of 9,431 (0.3%) for percutaneous transluminal coronary angioplasty, 1 of 317 (0.3%) for excimer laser, 8 of 104 (7.7%) for Rotablator (Heart Technologies, Bellevue, Washington), 21 of 469 (4.5%) for extraction atherectomy, and 6 of 355 (1.7%) for directional atherectomy. Compared with those without no-reflow, patients with no-reflow experienced a 10-fold higher incidence of in-hospital death (15%) and acute myocardial infarction (31%). Correlates of in-hospital mortality included acute myocardial infarction on presentation (p = 0.006) and final flow < 3 (as defined by the TIMI trial) at completion of the procedure (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Directional coronary atherectomy in unstable angina

OBJECTIVES

To determine whether excision of complex, ulcerated plaque improves the risk of patients with unstable angina to the level of those with stable angina, the results of directional coronary atherectomy were compared in patients with these two syndromes.

BACKGROUND

The procedural results of angioplasty in the setting of unstable angina are not as favorable as those observed for chronic stable angina, presumably because thrombus-associated plaque augments the risk of abrupt closure.

METHODS

Two hundred eighty-seven consecutive patients who had undergone directional atherectomy for a single new stenosis were studied. Seventy-seven patients had stable angina (Group I); 110 patients had progressively worsening angina in the absence of rest or postinfarction angina (Group II); and 100 patients had rest or postinfarction angina, or both (Group III).

RESULTS

Major ischemic complications (death, Q wave infarction, emergency bypass surgery) occurred more frequently in Group III (1.3% [Group I] vs. 0.9% [Group II] vs. 7% [Group III], p = 0.036). This difference was largely due to a higher incidence of emergency surgery in Group III (1.3% [Group I] vs. 0% [Group II] vs. 5% [Group III], p = 0.05). Clinical follow-up was obtained in 97% of successful procedures for a mean follow-up period of 22 months (range 9 to 52) and revealed a higher incidence of hospital admission for angina (p = 0.05) and a trend toward more bypass surgery (p = 0.09) and myocardial infarction (p = 0.16) in Group III. There was no difference in repeat percutaneous interventions among the three groups (range 19% to 24%, p = 0.75).

CONCLUSIONS

These results show that the definition of unstable angina is important in determining the immediate outcome of directional atherectomy. In the absence of rest or postinfarction angina, the immediate results are not significantly different from those obtained in stable angina. Our results also suggest that both the immediate and short-term outcome in unstable angina are not greatly influenced by atherectomy but more so by the pathophysiology of unstable angina, which increases the complications of percutaneous interventions.

Clinical significance of distal embolization after transluminal extraction atherectomy in diffusely diseased saphenous vein grafts

Standard balloon angioplasty of degenerated saphenous vein graft lesions may be complicated by distal embolization, particularly in the presence of intragraft thrombus. Transluminal extraction atherectomy may be useful in this setting because of its ability to remove particulate debris. This study was designed to identify the incidence and prognostic significance of distal embolization after transluminal extraction atherectomy in high-risk saphenous vein graft lesions. To address these issues the clinical course of 65 consecutive patients (86 high-risk saphenous vein graft lesions) was reviewed after extraction atherectomy. Distal embolization occurred in 11 (12.8%) of 86 high-risk lesions. The majority (63.6%) of these episodes occurred after adjunct balloon dilatation following uncomplicated use of the extraction atherectomy catheter. Correlates of distal embolization included patient age and the presence of intragraft thrombus. Major in-hospital complications developed more often in patients with distal embolization (46% vs 2% in those without distal embolization, p < 0.001), resulting in a reduced procedural success rate in this group (55% vs 91%, p = 0.01). We conclude that the risk of distal embolization after saphenous vein graft angioplasty, although potentially reduced, is not eliminated with transluminal extraction atherectomy, particularly in lesions with superimposed thrombus.

Clinical and angiographic outcome after directional coronary atherectomy. A qualitative and quantitative analysis using coronary arteriography and intravascular ultrasound

To assess clinical and angiographic outcome after directional coronary atherectomy, the clinical course of 306 patients undergoing this procedure was reviewed. Directional atherectomy was successful in 290 (94.8%) procedures; complications developed in 8 (2.6%) patients. After atherectomy, percent diameter stenosis was reduced from 71 +/- 14 to 14 +/- 14% (p < 0.001) and minimal lumen diameter was increased from 0.87 +/- 0.42 to 2.55 +/- 0.57 mm (p < 0.001). In 128 (42%) patients, adjunct balloon angioplasty was performed to treat either complications or a residual stenosis > 30%. Intravascular ultrasound was also performed in 57 patients after directional atherectomy and demonstrated that a significant amount of residual plaque mass remained in lesions with a calcium arc > or = 90 degrees (17 +/- 5 mm2 vs 12 +/- 5 mm2 in lesions without calcium; p = 0.007). During the 11 +/- 6 month follow-up period, 69 (28.3%) patients developed recurrent clinical events (death, 5; Q wave myocardial infarction, 8; coronary bypass surgery, 31; coronary angioplasty, 36). Using a proportional hazards model, independent predictors of late clinical events included diabetes mellitus (relative risk [RR] = 1.95; p < 0.05), unstable angina (RR = 2.78; p < 0.005) and a prior history of restenosis (RR = 2.21; p < 0.01). We conclude that directional atherectomy is associated with high procedural success rates and infrequent complications in selected lesions subsets, although the degree of plaque resection may be limited if extensive calcium is present. Late clinical events develop in some (28%) patients after directional atherectomy, related to certain preprocedural clinical risk factors.

Indications for directional coronary atherectomy: 1993

New coronary devices are being developed in attempts to solve the limitations of balloon angioplasty. Directional coronary atherectomy was the first of these devices to gain Food and Drug Administration approval. Theoretically, directional atherectomy improves coronary stenoses by an entirely different mechanism than balloon angioplasty, removing atherosclerotic plaque and leaving a smooth surface with less elastic recoil. Nonrandomized experience has shown that directional atherectomy is most useful in proximal to mid-segment, noncalcified, large (> 2.5 mm) coronary arterial segments, yielding minimal residual stenosis and larger lumen diameters than are generally achieved with angioplasty. Experience suggests that directional atherectomy is most useful in ostial coronary lesions, bifurcation stenoses, proximal left anterior descending lesions, discrete saphenous vein graft stenoses, complex or thrombus-containing lesions, highly eccentric lesions, and lesions failing PTCA secondary to elastic recoil, recurrent thrombosis, or limited dissection. Dissection and out-of-catheterization-laboratory acute closure are infrequent and appear to be improved over balloon angioplasty. However, intimal hyperplasia leading to restenosis is not solved by directional atherectomy. Randomized studies such as the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) will help to clarify further the overall utility of directional atherectomy compared with balloon angioplasty in the future, but due to the limited power of subgroup analyses, CAVEAT may not have fully defined all the specific lesion characteristics that may be improved by atherectomy over PTCA. Review of the data presented may help the clinician identify specific areas in which atherectomy appears to offer an advantage over angioplasty, although definitive answers await specifically targeted randomized trials.

Directional coronary atherectomy of saphenous vein graft narrowings: multicenter investigational experience

Directional coronary atherectomy (DCA) of saphenous vein graft lesions was performed at 21 centers between June 1988 and September 1990, which represents the multicenter investigational experience. A total of 318 procedures were performed and 363 vein graft lesions were treated. Angiographic success with DCA was achieved in 86% of lesions and clinical success was achieved in 85% (269 of 318) of patients. Major complications occurred in 2.5% of patients, with Q wave myocardial infarction (MI) in 1.3%, death in 0.9%, and urgent bypass surgery in 0.9%. Other complications included non-Q wave MI in 4.4%, distal embolization in 7.2%, coronary occlusion in 1.9%, and vessel perforation in 0.6%. Although there was a trend toward lower success rates with ostial vein graft lesions (82% vs 88% for other graft sites) and with diffuse (length > 20 mm) graft lesions (75% vs 87% for shorter lesions), the differences were not significant. Baseline clinical and angiographic factors did not identify predictors of lower success or more frequent complications in the study group. Overall restenosis rate in the 149 patients with angiographic restudy was 57%. The restenosis rate was significantly lower with primary vein graft lesions (38%) compared with a 75% restenosis rate for grafts with prior restenosis, p < 0.001. This initial multicenter investigational experience indicates that directional coronary atherectomy is a safe and effective therapy for selected saphenous vein graft disease. Although the overall restenosis rate is relatively high, the restenosis rate following DCA of primary vein graft lesions is significantly lower than for vein grafts having had prior intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Specific indications for directional coronary atherectomy: origin left anterior descending coronary artery and bifurcation lesions

Directional coronary atherectomy is emerging as the treatment of choice for many patients with significant lesions involving left anterior descending coronary artery origin or vessel bifurcations. It offers the potential advantages of safe, reliable, and predictable treatment of these selected complex lesions. Future modifications and improvements in the design of the atherectomy device (AtheroCath; Devices for Vascular Intervention, Redwood City, CA) may further expand its application to smaller and calcified vessels.

Results of directional coronary atherectomy during multicenter preapproval testing. The US Directional Coronary Atherectomy Investigator Group

Between 1988 and 1990, clinical testing was performed at 12 US institutions using the Simpson Coronary AtheroCath under an Investigational Device Exemption. Data on 1,069 lesions (873 patients) were analyzed and presented to the Food and Drug Administration (FDA) advisory panel in the summer of 1990, forming the basis for approval of this device in September 1990. Analysis of these preapproval data shows a primary success rate of 85% (defined as tissue removal, > or = 20% reduction in stenosis, < 50% residual stenosis after directional atherectomy, and no major complication), with somewhat higher primary success in prior restenosis and noncalcified lesions. Including the use of conventional angioplasty performed after atherectomy, the overall success rate was 92%. One or more major complications occurred in 4.9% of procedures, and included death (0.5%), nonfatal Q-wave myocardial infarction (0.9%), and emergency bypass surgery (4.0%). These complications were more frequent in right coronary, de novo, and diffuse (> 20-mm length) lesions. Six-month angiography results were available in 384 (77%) of 498 lesions eligible for follow-up when the registry closed and showed a restenosis rate (late stenosis > 50%) of 42%. The restenosis rate in both native vessels (30 vs 46%) and bypass grafts (31 vs 68%) was lower in primary (de novo) lesions compared with lesions that had developed restenosis after a prior intervention. Despite the use of prototype atherectomy catheters and still evolving procedural technique, this preapproval experience provided an important initial indication of the situations in which directional coronary atherectomy was most useful and helped set clear standards for performance of this procedure following FDA approval.

Multicenter clinical experience with rescue atherectomy for failed angioplasty

Directional coronary atherectomy (DCA) has been proposed as a "rescue" technique for failed or suboptimal percutaneous transluminal coronary angioplasty (PTCA) in an attempt to avoid myocardial infarction or emergency coronary artery bypass grafting. In this report we review the utilization and outcome of rescue atherectomy from the clinical experience of The Cleveland Clinic Foundation and Medical College of Virginia from November 1988 through January 1993, and from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) database. This analysis includes 100 patients with 103 treated lesions from 44 patients at the Cleveland Clinic, 36 patients from the Medical College of Virginia, and 20 patients from the CAVEAT database. The etiology of failed PTCA was primarily from dissection in 52 lesions (50.5%), "recoil" in 43 lesions (41.8%), and recurrent thrombosis in 8 lesions (7.8%). Complete vessel closure was present in 23 lesions (22.3%). The vessels treated included 51.5% left anterior descending, 24.3% right coronary, and 16.5% circumflex coronary arteries. The average reference vessel diameter in the group was 3.10 +/- 0.06 mm (SEM), with an average stenosis of 78.9 +/- 1.2% before PTCA, 55.8 +/- 2.4% after PTCA, and 24.1 +/- 2.2% after rescue DCA. DCA was successful (Thrombosis in Myocardial Infarction [TIMI] grade 3 flow with > 20% stenosis reduction without death, Q-wave myocardial infarction, or coronary artery bypass grafting) in 94 of 103 lesions (91.3%). Complications included 1 patient with perforation (1%), 2 deaths within 24 hours (2.0%), and 6 patients requiring coronary artery bypass grafting (6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Experience with directional coronary atherectomy since pre-market approval

Directional coronary atherectomy (DCA) received Food and Drug Administration (FDA) Pre-Market Approval in September 1990 and was then released through formal training certification of physicians at each new site. Procedure volume has increased dramatically since approval, with > 17,000 DCA procedures performed in 1991 and a cumulative total of > 33,000 procedures by mid-1992, at > 670 centers in the United States. Clinical application and results since approval have generally been similar to preapproval multicenter investigational results. Comparison of pre- and postapproval usage at the Medical College of Virginia shows similar baseline characteristics and indications, although recent patients show a higher proportion of "salvage" DCA for failed or suboptimal angioplasty (6% vs 14%) or DCA in combination with multidevice multiple vessel intervention (30% vs 38%). Overall results in 300 patients and 345 procedures included procedural success in 95%, clinical success in 94%, with major complications in 4.6% (including urgent bypass surgery in 3.8%, Q wave myocardial infarction in 1.7%, and hospital mortality in 0.3%). Results before and after FDA approval were similar for procedural success (94% vs 96%), clinical success rate (94% vs 94%), and major complications (5.5% vs 4.4%). There was a trend toward lower urgent surgery rate (5.4% vs 3.3%) in the more recent experience. In addition to its established efficacy for highly eccentric lesions, newer applications for which DCA is being used following FDA approval include treatment of saphenous vein grafts, thrombus-associated lesions, aorto-ostial lesions, failed or suboptimal percutaneous transluminal coronary angioplasty result, bifurcation lesions, and use as part of multivessel intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanisms of angiographically successful directional coronary atherectomy: evaluation by intracoronary ultrasound and comparison with transluminal coronary angioplasty

To assess the mechanisms of luminal improvement, 40 patients undergoing directional coronary atherectomy and a matched control group of 25 patients undergoing angioplasty were evaluated with intracoronary ultrasound imaging before and after intervention. Despite similar sized vessels, a similar angiographic severity of diameter stenosis (75 +/- 12% for the angioplasty group vs 69 +/- 15% for the atherectomy group, p = NS), and a similar plaque burden (percent plaque area) before intervention (84 +/- 5% in the angioplasty group vs 85 +/- 13% in the atherectomy group, p = NS), the residual plaque area after intervention was significantly smaller in the atherectomy group (54 +/- 14%) compared with the angioplasty group (65 +/- 13%, p = 0.002). Despite excellent angiographic results, significant residual plaque was noted after either successful intervention. Based on the absolute changes in lumen area, plaque area, and vessel area, improvement in the lumen area in the atherectomy group occurred as a result of plaque "compression" (48%), plaque removal (37%), and vessel expansion (15%). In the angioplasty group, plaque "compression" accounted for 94% of the improvement in lumen area, whereas vessel expansion contributed 6%. Thus "compression" of plaque remains the major mechanism of luminal improvement during atherectomy.

Intracoronary ultrasound predictors of adverse outcomes after coronary artery interventions

OBJECTIVES

The purpose of this study was to determine the association between qualitative and quantitative lesion characteristics as assessed by intracoronary ultrasound imaging and adverse outcomes after coronary artery interventions.

BACKGROUND

Restenosis and other adverse outcomes after coronary artery interventions may be difficult to predict from clinical or angiographic data. Intracoronary ultrasound imaging provides additional data that could prove useful.

METHODS

Immediately after successful coronary artery interventions (angiographic residual stenosis < or = 50%), 69 patients underwent intracoronary ultrasound imaging. Images were assessed qualitatively for plaque composition and topography and for dissection. Quantitative data included measurement of minimal lumen diameter, lumen area, plaque area and percent area stenosis at the treatment and adjacent reference sites. Adverse outcome was defined as death, coronary bypass surgery, myocardial infarction or angiographic restenosis.

RESULTS

Of the 69 patients, 1 died, 3 had bypass surgery and 1 had a myocardial infarction before planned 6-month repeat catheterization. Two patients were lost to follow-up study. Of the remaining 62 patients, 56 (90%) agreed to follow-up catheterization and 25 (45%) of the 56 had restenosis. Thus, 30 patients had an adverse outcome and 37 had no adverse event. The incidence of dissection detected by ultrasound imaging after an intervention was significantly greater in patients with than in those without a subsequent adverse event (63% vs. 35%, p < 0.05). The severity of dissection also appeared to be related to outcome (p < 0.05). Other qualitative and quantitative variables were not significantly different between the two patient groups.

CONCLUSIONS

Dissection, as assessed by intracoronary ultrasound imaging after a coronary artery intervention, can identify patients at increased risk of subsequent adverse events. Additional studies are warranted to explore whether such imaging may allow modification of interventional procedures to improve outcome.

Long-term results of directional coronary atherectomy: predictors of restenosis

OBJECTIVES

This study was performed to obtain better understanding of the long-term clinical efficacy of directional coronary atherectomy.

BACKGROUND

Although this procedure yields favorable acute results, its acceptance has been limited by the perception that late results (that is, freedom from restenosis) are no better than those of conventional angioplasty.

METHODS

A total of 225 atherectomies performed in 190 patients between August 1988 and July 1991 were examined. Minimal lumen diameter of the treated segments was measured on angiograms obtained before, after and 6 months after intervention.

RESULTS

Although most lesions (97%) had one or more characteristics predictive of unfavorable short- or long-term results after conventional angioplasty, atherectomy was successful in 205 lesions (91%) with a mean residual stenosis of 7 +/- 16%. After subsequent balloon angioplasty in 16 unsuccessful atherectomy attempts, procedural success was 98%. There were no deaths or Q wave myocardial infarctions, and one patient (0.5%) underwent emergency bypass surgery. Six-month angiographic follow-up was obtained in 77% of the eligible patients. The overall angiographic restenosis rate was 32%. Predictors of a lower restenosis rate included a postprocedure lumen diameter > 3 mm (24% vs. 39%, p = 0.047), serum cholesterol < or = 200 mg/dl (18% vs. 40%, p = 0.018) and recent myocardial infarction (16% vs. 37%, p = 0.034). Life-table analysis showed a 2% mortality rate and a 26% incidence of other events (myocardial infarction, repeat revascularization) within the 1st year. The annual 5% mortality rate and 7% incidence of other events during years 2 and 3 were related in large part to the existence or progression of disease at other locations.

CONCLUSIONS

Six-month angiographic follow-up of patients who underwent directional coronary atherectomy during the 1st 3 years of our experience shows an overall restenosis rate of 32%, with lower rates in patients with a postatherectomy lumen diameter > or = 3 mm, cholesterol level < or = 200 mg/dl or a recent myocardial infarction. Few if any events relating to the site of atherectomy developed after the 1st year of follow-up.