Coronary Angioplasty Versus Excisional Atherectomy Trial Research Articles

Periprocedural Cardiac Enzyme Elevation Predicts Adverse Outcomes

Extensive clinical investigation throughout the 1990s validated periprocedural myonecrosis as a powerful predictor of adverse outcomes, so it is surprising that this remains a contentious point. Originally derided as “enzyme leaks” or “myocardial infarctlets,” periprocedural myocardial infarction (MI) has now been definitively linked in large data sets to long-term adverse outcomes, most notably mortality. It is not, however, always directly contributory or causative. For example, a large creatine kinase (CK) elevation caused by closure of a major side branch resulting in chest pain and development of new Q waves is obviously undesirable and causally related to the interventional procedure. Alternatively, even small, asymptomatic CK elevations have been clearly associated with worse long-term outcome, and although this may in part be causally related to the procedure, it is more likely that the relationship is caused by the underlying predisposing factors that led to the periprocedural MI, such as arterial inflammation predilecting to the occurrence of embolization or to a large degree of atheroma burden leading to more myonecrosis. Under these circumstances, it is likely that the heightened inflammatory state and the diffuse disease that is present are the real causative factors for worse long-term outcomes. Recently, aspirin resistance has been demonstrated to predict periprocedural myonecrosis. Thus, both through direct causation and also as an epiphenomenon, embolization and attendant periprocedural myonecrosis are associated with short, intermediate, and long-term adverse outcomes (Table 1). This review details this evolution in thought. View this table: TABLE 1. Mechanisms Behind Periprocedural Myonecrosis Periprocedural myonecrosis is a frequent occurrence in percutaneous coronary intervention (PCI). CK or CK myocardial band (CK-MB) elevation occurs in ≈25% of patients undergoing PCI. With the advent of sensitive troponin measurements, it is clear that at least 50% of patients undergoing PCI have postprocedural troponin elevation, reflecting the frequency with which embolization occurs. However, troponin offers …

Is all unstable angina the same? Insights from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I)

Background Certain characteristics of unstable angina have been associated with worse clinical outcomes after percutaneous revascularization procedures. Methods And Results We compared outcomes of patients with (n = 690) and those without (n = 320) unstable angina in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) by unstable angina subgroup: rest chest pain, postinfarction chest pain, chest pain with ischemic electrocardiographic changes, chest pain with recent acceleration, and no chest pain. Regression models were constructed to predict in-hospital and 6-month composite end point death, infarction, bypass surgery, percutaneous revascularization, and abrupt closure (in-hospital) or restenosis (6 months) for each subgroup. Only chest pain with electrocardiographic changes predicted the composite in-hospital outcome (24% vs 17% with no chest pain, P =.0374.) This subgroup also had a greater acute gain, more late loss, and more restenosis than patients in the other subgroups. Rest chest pain carried a higher incidence of the composite 6-month outcome (39.9% vs 29% with no chest pain, P =.0472). For all unstable angina categories, atherectomy was associated with worse overall outcomes than angioplasty. Conclusions Patients with unstable angina have more complications of percutaneous revascularization than patients without unstable angina, but event rates vary by anginal subgroup. The clinical presentation may help to identify unstable angina patients at particularly high risk for adverse outcomes. (Am Heart J 1999;137:227-33.)

Influence of a Randomized Clinical Trial on Practice by Participating Investigators: Lessons From the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT)

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.

Use of Evidence-Based Medical Therapy in Patients Undergoing Percutaneous Coronary Revascularization in the United States, Europe, and Canada

The objective of this study was to examine whether there are international variations in the use of evidence-based medical therapy in patients undergoing percutaneous coronary revascularization. We analyzed the medical therapy of patients in the United States (US) (n = 878), Europe (n = 134), and Canada (n = 274) who underwent percutaneous coronary revascularization in either the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) (enrollment from August 1991 to April 1992) or the Canadian Coronary Atherectomy Trial (CCAT) (enrollment from July 1991 to August 1992). We found that at the time of hospital admission, Canadian patients had the highest rates of treatment with aspirin (95% vs 57% US and 78% Europe; p = 0.002), calcium antagonists (75% vs 48% US and 43% Europe; p = 0.0001), β blockers (60% vs 32% US and 46% Europe; p = 0.02), and combination anti-ischemic therapy (67% vs 43% US and 56% Europe; p = 0.0001). By discharge, however, Canadian patients had the lowest rates of treatment with nitrates (12% vs 40% US and 44% Europe; p = 0.0001) and combination anti-ischemic therapy (29% vs 53% US and 47% Europe; p <0.01). At both admission and discharge, rates of treatment with angiotensin-converting enzyme inhibitors and lipid-lowering agents were <15% in all 3 regions. We conclude that significant international variations exist in the use of evidence-based medical therapy in patients undergoing percutaneous coronary revascularization.We analyzed data on medical therapy from patients who participated in the CAVEAT-I and CCAT trials. We found that among patients undergoing percutaneous coronary revascularization in the United States, Europe, and Canada, there are significant international variations in the use of evidence-based medical therapy.

Impact of Diabetes Mellitus on Percutaneous Revascularization (CAVEAT-I)

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.

Use of calcium channel antagonists in myocardial revascularization procedures

Calcium channel antagonists possess a number of properties that may be beneficial after revascularization procedures. Therefore, we present an overview of the use of these drugs after percutaneous intervention in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT), and compare the results in CAVEAT with those in published randomized trials. Also reviewed are the use of calcium channel antagonists to control perioperative hypertension, reduce myocardial necrosis, and prevent arrhythmias during cardiopulmonary bypass.

Abrupt closure: The CAVEAT I experience

This study sought to assess the incidence and consequences of abrupt closure in a series of patients undergoing directional coronary atherectomy versus percutaneous coronary angioplasty. Abrupt closure with coronary angioplasty has been associated with adverse outcome. The results from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I, a randomized trial of coronary angioplasty versus directional coronary atherectomy, were analyzed. This multicenter trial enrolled 1,012 patients from 1991 to 1992. All records from patients with abrupt closure, which was coded as a discrete complication, were reviewed. Abrupt closure occurred in 60 patients (5.9%) and was associated with a significantly longer hospital stay (median 8 vs. 3 days). Severe proximal target vessel tortuosity was more common in patients with abrupt closure (20.3% vs. 11.6%, p = 0.046), as was preexistent coronary artery thrombus (30.5% vs. 18.3%, p = 0.02). Abrupt closure was associated with a marked increase in subsequent complications (myocardial infarction 46.7% vs. 2.1%, emergency bypass surgery 38.3% vs. 0.32%, death 33% vs. 0%) and occurred more frequently in the directional coronary atherectomy group (8.0% vs. 3.8%, p = 0.005). In the coronary angioplasty group, the occlusion usually occurred at the target lesion (91%), presumably related to the effects of barotrauma. In the directional coronary atherectomy group, the site of the occlusion was the target lesion in only 58% (p = 0.045). The remaining occlusions related to problems with the technique (guide catheter or nose cone trauma), reflecting the fact that directional coronary atherectomy is a more complex procedure. Abrupt closure remains the principal determinant of adverse outcome after percutaneous procedures for the treatment of coronary artery disease. Although abrupt closure is more common with directional atherectomy than angioplasty, the sequelae are similar.

Peripheral vascular complications in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I)

In-hospital peripheral vascular complications of balloon angioplasty were compared with those of directional atherectomy in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I) to identify patients at risk and evaluate costs and outcomes. The incidence, costs and outcomes of peripheral vascular complications after coronary intervention have not been fully characterized as a function of randomly assigned therapy. At 35 sites in the United States and Europe, 1,012 patients were randomized. Peripheral vascular complications were defined as the composite of pulse loss, pseudoaneurysm, hematoma > 4 cm in diameter or groin hemorrhage necessitating blood transfusion. Logistic models were derived to 1) predict these complications from baseline and procedural characteristics, 2) test the relevance of randomization assignment, and 3) assess their impact on hospital costs and long-term outcomes. Sixty-seven patients (6.6%) developed peripheral vascular complications, of whom 15 (22.4%) required a blood transfusion, 14 (20.9%) underwent vascular surgery, and 2 (3.0%) died. Both in-hospital deaths occurred in patients with peripheral vascular complications. There was no difference in composite peripheral vascular complication rates among patients randomized to angioplasty or atherectomy. Greater age, female gender, postprocedural heparin and intraaortic balloon counterpulsation were predictive of increased risk. In a representative 60% subset, mean hospital costs increased from $9,583 in patients without to $18,350 in those with peripheral vascular complications (p = 0.0001). The unadjusted mortality rate at 1 year was 7.5% for patients with peripheral vascular complications compared with 1.1% for all others (p = 0.0001). These complications identified patients at greater risk of death, myocardial infarction or repeat revascularization at 30 days and 1 year. The atherectomy group had a trend toward more frequent deaths and myocardial infarction. Directional atherectomy and balloon angioplasty had similar in-hospital peripheral vascular complication rates. Female gender, greater age, postprocedural heparin and intraaortic balloon counterpulsation were predictive of higher risk. The twofold increase in cost and sevenfold increase in long-term deaths highlight the need to prevent these periprocedural events and monitor patients closely.

Characteristics and consequences of myocardial infarction after percutaneous coronary intervention: Insights from the coronary angioplasty versus excisional atherectomy trial (CAVEAT)

Objectives. We examined the results of the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) to determine the characteristics and consequences of creatine kinase (CK) and creatine kinase, MB myocardial isoenzyme fraction (CK-MB) elevations after percutaneous coronary intervention.Background. Enzyme elevations after interventional procedures have usually been thought to be without long-term clinical consequences. However, recent preliminary reports have suggested that there are important long-term clinical sequelae in patients with even mild enzyme elevations after coronary procedures.Methods. Patients with new native lesions undergoing coronary intervention at 35 clinical sites were randomized to undergo percutaneous coronary angioplasty (n = 500) or directional coronary atherectomy (n = 512). Cardiac enzyme levels were measured 12 and 24 h after the interventional procedure and when clinically indicated for recurrent myocardial ischemia. Enzyme profiles were analyzed using a ratio that compared the peak enzyme level and the local laboratory upper limit of normal. Standard 12-lead electrocardiograms (ECGs) recorded before and after the procedure were interpreted by two independent readers who had no knowledge of the randomization data. Postprocedural myocardial infarction was defined as the appearance of new Q waves on the ECG, CK-MB levels three or more times the upper limit of normal or a total CK concentration two or more times the upper limit of normal when CK-MB levels were unavailable. Regression models were used to evaluate the predictive significance of a postintervention myocardial infarction with respect to clinical outcomes at 30 days and 1 year.Results. There were 78 myocardial infarctions in the atherectomy group and 34 in the angioplasty group (15.2% vs 6.8%, p = 0.001). Patients with a myocardial infarction more often had a repeat intervention or emergency coronary artery bypass surgery. Hospital length of stay was increased among patients with an infarction, as were mean hospital costs ($17,340.65 vs $11,308.47, p = 0.0003). Postprocedural myocardial infarction was highly predictive of mortality, bypass surgery or repeat intervention within 30 days (p < 0.0001).Conclusions. Myocardial infarction occurred commonly after coronary intervention in CAVEAT and was associated with a worse clinical outcome. Although the incidence of myocardial infarction was higher with atherectomy than with angioplasty, the baseline characteristics and consequences of the infarctions were similar between the treatments with regard to 30-day outcome. Myocardial enzyme elevations after an otherwise successful interventional procedure may identify a population at risk for a future cardiac event.

Directional atherectomy versus balloon angioplasty for coronary ostial and nonostial left anterior descending coronary artery lesions: Results from a randomized multicenter trial

We hypothesized that atherectomy would be superior to balloon angioplasty for ostial and nonostial left anterior descending coronary artery lesions. Balloon angioplasty of ostial coronary artery lesions has been associated with a lower procedural success rate and a higher rate of complications and of restenosis than angioplasty of nonostial stenoses. Directional coronary atherectomy has been proposed as an alternative therapy for ostial lesions. In the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), 1,012 patients were randomized to undergo either procedure; 563 patients had proximal left anterior descending coronary artery lesions, of which 74 were ostial. We compared balloon angioplasty with directional atherectomy for early and 6-month results for ostial as well as nonostial proximal left anterior descending coronary artery lesions. Directional atherectomy led to an initially higher gain in minimal lumen diameter for ostial lesions (1.13 vs. 0.56 mm, respectively, p < 0.001) but a higher rate of adjudicated non-Q wave myocardial infarction (24% vs. 13%, respectively, p < 0.001) than balloon angioplasty and no improvement in restenosis rates (48% vs. 46%, respectively). In the nonostial proximal left anterior descending coronary artery lesions, angiographic restenosis was reduced (51% vs. 66%, p = 0.012), but this was also associated with a higher rate of periprocedural myocardial infarction (8% vs. 2%, p = 0.008 by site and 24% vs. 8%, p < 0.001 by adjudication) and no difference in the need for subsequent coronary artery bypass surgery (7.3% vs. 8.4%, respectively) or repeat percutaneous coronary intervention (24% vs. 26%, respectively). For ostial left anterior descending coronary artery stenoses, both procedures yielded similar rates of initial success and restenosis, but atherectomy was associated with more non-Q wave myocardial infarction. In this trial the predominant angiographic benefit (increased early gain and less angiographic restenosis) of atherectomy for the left anterior descending coronary artery was in proximal nonostial lesions. However, the tradeoffs for this angiographic advantage were more in-hospital myocardial infarctions and no decrease in clinical restenosis.

1018-46 Influence of Randomized Trials on Clinical Practice: A Comparison of Directional Atherectomy and New Device Use Before and After the CAVEAT Trial at CAVEAT Sites

In order to evaluate the impact of the Coronary Angioplasty versus Excisional Atherectomy Trial (CAVEAT-I) on practice patterns of coronary intervention, a week-long registry of the “universe” of all coronary interventions performed at 35 investigational sites between April 18 and 22, 1994 was compared with a similar registry obtained before the trial was initiated. A total of 97% of sites responded. Additional sites which took part in CAVEAT-II comparing DCA and PTCA in vein grafts were also audited for generalizability:DeviceCAVEAT-I sitesCAVEAT-II sitespre-CAVEATpost-CAVEATpost-CAVEATn%n%n%PTCA53983.844.368.530778.1DCA6910.79114.1399.9Other355411317.54712* P &lt; 0.0001*p value for comparison of CAVEAT-I sites pre vs. post CAVEAT p value for comparison of CAVEAT-I sites pre vs. post CAVEAT There has been a significant decline in the proportion of procedures relying exclusively on balloon angioplasty and paradoxically, despite the negative findings of CAVEAT-I, a noteworthy trend towards an increase in use of DCA and other devices at CAVEAT sites. This paradoxic increase in trend was still evident when subgroup analysis of American and European CAVEAT-I sites was performed. These findings suggest that even among investigators in the trial, there is a lack of influence of CAVEAT-I data on clinical practice patterns.

Randomized trials of directional coronary atherectomy: Implications for clinical practice and future investigation

Objectives. This study compared and contrasted the randomized trials of directional atherectomy and coronary angioplasty for de novo native coronary artery lesions.Background. The results of two randomized trials, the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) and the Canadian Coronary Atherectomy Trial (CCAT), comparing initial and intermediate-term outcome of directional coronary atherectomy and conventional coronary angioplasty in de novo native vessels, have been reported. In CAVEAT any coronary artery segment that could be by either technique was included; in CCAT only nonostial proximal left anterior descending coronary artery stenoses were studied.Methods. The primary end point was 6-month angiographic restenosis. Clinical outcome end points at 6 months included death, myocardial infarction, emergency bypass surgery and abrupt closure.Results. Initial angiographic success rates were significantly improved with directional coronary atherectomy compared with conventional angioplasty (89% vs. 80% for CAVEAT; 98% vs. 91% for CCAT). Also, the initial improvement in minimal lumen diameter and final immediate postprocedural residual diameter stenosis were better with atherectomy. In CCAT, there was no difference in initial complications; in CAVEAT, non-Q wave myocardial infarction rates and abrupt closure were increased with atherectomy. Despite improved success rates and better lumen achieved with atherectomy, in CCAT there was no difference in angiographic restenosis (46% for directional atherectomy vs. 43% for angioplasty). In CAVEAT, in a prespecified subset analysis involving the proximal left anterior descending coronary artery, restenosis was both significantly and clinically less for directional atherectomy (51% vs. 63%). For non-left anterior descending coronary artery segments, there was no difference.Conclusions. These studies document the difference between achievement of an excellent initial angiographic result and the longer term issue of clinical restenosis. Widespread use of directional coronary atherectomy to treat lesions that would be well treated by angioplasty in an attempt to decrease restenosis rates substantially does not appear indicated by the data. In individual lesions, directional atherectomy should be selected with the view toward optimizing initial results. Further trials are needed to determine whether more aggressive or better targeted directional coronary atherectomy may improve not only the initial gain but the long-term outcome as well.

Indications for directional coronary atherectoy:1993

New coronary devices are being developed in attempts to solve the limitations of balloon angoplasty. 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 angoplasty. 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 angoplasty 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.

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 (PICA) 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 PICA 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%). In 33 patients with TIMI grade 0–2 flow or acute closure after PTCA, TIMI grade 3 flow was restored in 30 (90.9%). Rescue atherectomy thus may play a beneficial role in the treatment of acute angioplasty complica tions and/or suboptimal results, although vessel perforation is an uncommon complication.