The platelet function dose-response to abciximab during percutaneous coronary revascularization is variable.

The platelet function dose-response to incremental abciximab (Reopro, Eli Lilly/Centocor, Indianapolis, IN) bolus dosing during percutaneous coronary intervention (PCI) was evaluated in 85 patients using a point-of-service platelet function assay. Patients received incremental bolus doses of abciximab at 10- to 20-min intervals; platelet function was measured at 10-min intervals during dosing. The percentage of patients achieving > or = 80% inhibition of platelet function after 50%, 75%, and 100% of a standard abciximab bolus was 40%, 87%, and 95%, respectively. There were no significant associations between the platelet function dose-response to abciximab and age, weight, platelet count, hematocrit, heparin dose, peak activated clotting time, thienopyridine use prior to PCI, gender, cigarette smoking, diabetes mellitus, or clinical syndrome. This study demonstrated significant interpatient variability in platelet function dose-response to abciximab with a substantial proportion (87%) of patients achieving high-level platelet function inhibition with less than the standard abciximab bolus dose.

Clinical application of procedural platelet monitoring during percutaneous coronary intervention among patients at increased bleeding risk.

The goal of platelet function testing in the catheterization laboratory is to provide information about the platelet contributions to the risk of thrombotic or hemorrhagic events and optimization of anti-platelet therapy for percutaneous interventions. We present several illustrative cases in which platelet monitoring with the Rapid Platelet Function Assay (RPFA, Accumetrics) was used to guide dosing of a glycoprotein (GP) IIb/IIIa inhibitor for coronary and peripheral intervention among patients at increased bleeding risk.

Effectiveness of rotational atherectomy of right coronary artery ostial stenosis.

Balloon angioplasty and stenting of right coronary ostial stenosis may frequently be impeded by lesion calcification, whereas rotational atherectomy, which ablates calcified plaque, should treat these lesions effectively. Accordingly, we evaluated procedural success and longterm clinical outcome of rotational atherectomy of right coronary ostial stenosis. Procedural data were obtained from a comprehensive interventional registry and follow-up information was obtained by chart review and patient enquiry. All patients who developed recurrent angina underwent angiographic restudy. During a 5-year interval, 119 patients underwent rotational atherectomy of right coronary ostial stenosis. Multilesion interventions were performed in 55% of patients. Ostial lesions were 3.73+/-3.69 mm in length (mean +/- SD), and 57.1% were significantly calcified. Reference vessel diameter was 3.42+/-0.56 mm. Maximum burr:artery ratio was 0.64+/-0.1 with adjunct balloon angioplasty in 89.1% and adjunct stenting in 9.2%. Procedural success (<50% residual stenosis without major complication) was 97.5%, with 1.7% uncomplicated failure and 0.8% Q-wave infarction. Maximum residual stenosis was 15+/-17%. During 6-month follow-up, available in 94% of patients, 82.7% remained angina-free, 10.9% developed recurrent angina due to right coronary ostial restenosis, and 6.4% developed recurrent angina due to another lesion. Two years after intervention, target lesion revascularization rate was 16%. Predictors of symptomatic angiographic restenosis were dissection >10 mm, final minimal luminal diameter <2.5 mm, lesion length >10 mm, restenotic lesion, and diabetes. We conclude that rotational atherectomy of right coronary ostial stenosis results in excellent acute procedural success and in low incidence of clinical recurrence, with a high proportion of patients remaining angina-free 2 years after intervention.

Abciximab and bleeding during coronary surgery: results from the EPILOG and EPISTENT trials. Improve Long-term Outcome with abciximab GP IIb/IIIa blockade. Evaluation of Platelet IIb/IIIa Inhibition in STENTing.

BACKGROUND: Abciximab during percutaneous coronary revascularization reduces ischemic complications, but concern exists regarding increased bleeding risk should emergency coronary surgical procedures be required. METHODS: Outcomes were assessed among 85 patients who required coronary artery bypass grafting operations after coronary intervention in two randomized placebo-controlled trials of abciximab. Comparisons were made between patients in the pooled placebo and abciximab groups. RESULTS: The incidence of coronary surgical procedures was 2.17% and 1.28% among patients randomized to placebo and abciximab, respectively (p = 0.021). Platelet transfusions were administered to 32% and 52% of patients in the placebo and abciximab groups, respectively (p = 0.059). Rates of major blood loss were 79% and 88% in the placebo and abciximab groups, respectively (p = 0.27); transfusions of packed red blood cells or whole blood were administered in 74% and 80% of patients, respectively (p = 0.53). Surgical reexploration for bleeding was required in 3% and 12% of patients, respectively. Death and myocardial infarction tended to occur less frequently among patients who had received abciximab. CONCLUSIONS: Urgent coronary artery bypass grafting operations can be performed without an incremental increase in major hemorrhagic risk among patients on abciximab therapy.

Coronary artery stent restenosis responds favorably to repeat interventions.

One hundred sixty patients who underwent a percutaneous intervention for treatment of in-stent restenosis were evaluated on clinical follow-up to determine the predictors of reintervention, and also to compare rotational atherectomy with repeat percutaneous transluminal coronary angioplasty (PTCA) for this condition. Current smoking and saphenous vein graft location were the independent predictors of target vessel revascularization (TVR), and there was no difference in the rate of TVR between rotational atherectomy and re-PTCA.

The importance of proteinuria as a determinant of mortality following percutaneous coronary revascularization in diabetics.

OBJECTIVES: The aims of this study were to compare mortality and clinical events following percutaneous coronary intervention (PCI) between nondiabetics and diabetics with and without proteinuria. BACKGROUND: Diabetics have increased rates of late myocardial infarction, repeat revascularization and mortality when compared with nondiabetics following PCI. Proteinuria is a marker for diabetic nephropathy and potentially a surrogate marker for advanced atherosclerosis. It is unknown if proteinuria is a predictor of outcome in diabetics following PCI. METHODS: We performed an observational study of 2,784 patients who underwent PCI at the Cleveland Clinic between January 1993 and December 1995. There were 2,247 nondiabetics and 537 diabetics with urinalysis and follow-up data available (proteinuria n = 217, nonproteinuria n = 320). The diabetic proteinuria group was further prospectively stratified into low concentration (n = 182) and high concentration (n = 35). The end points were all-cause mortality and the composite end point of death, nonfatal myocardial infarction (MI) and need for revascularization. RESULTS: The mean follow-up time was 20.2 months. The two-year mortality rate was 7.3% and 13.5% for nondiabetics and diabetics, respectively (p < 0.001). The two-year mortality rate was 9.1% and 20.3% for the nonproteinuria and proteinuria groups, respectively (p < 0.001). There was a graded increase in mortality comparing the diabetic group. The two-year mortality rate was 9.1%, 16.2% and 43.1% for the nonproteinuria, low concentration and high concentration groups, respectively (p < 0.001). The difference in survival between the nondiabetic and nonproteinuric diabetics was not significant (p = 0.8). CONCLUSIONS: The presence of proteinuria is the key determinant of risk following PCI for diabetics. Diabetics without evidence of proteinuria have similar survival compared with nondiabetics.

Comparison of slow oscillating versus fast balloon inflation strategies for coronary angioplasty.

Previous studies suggest that slow and/or oscillating balloon inflation during coronary angioplasty may decrease the incidence of coronary dissection and improve clinical outcomes. To compare the effect of slow oscillating versus conventional fast inflation techniques on the incidence of severe coronary dissection during angioplasty, 622 patients were randomized to slow oscillating inflation versus fast inflation. Angiographic outcomes of the procedures and in-hospital clinical events were recorded. The primary end point of severe (type C, D, E, F) dissection occurred in 7.7% of patients undergoing slow oscillation and 6.6% of patients undergoing fast inflation (p = 0.87). Major complications (death, urgent coronary artery bypass graft surgery, stroke, abrupt closure, or Q-wave myocardial infarction) occurred in 4.7% of patients undergoing slow oscillation and 3.5% of patients undergoing fast inflation (p = 0.45). The 2 inflation strategies did not differ in the pressure at which the balloon achieved full expansion, angiographic success rate, residual stenosis, and incidence of all minor and/or major complications. We conclude that there is no benefit of slow oscillating inflation over routine fast inflation in angioplasty. Slow oscillating inflation did not dilate lesions at lower pressures, decrease the incidence of dissection or severe dissection, or reduce the incidence of adverse clinical outcomes.

First chronic platelet glycoprotein IIb/IIIa integrin blockade. A randomized, placebo-controlled pilot study of xemilofiban in unstable angina with percutaneous coronary interventions.

BACKGROUND: Clinical studies have demonstrated the efficacy of intravenous administration of agents that block platelet glycoprotein IIb/IIIa receptors in the setting of percutaneous coronary revascularization. Although the optimal duration of treatment has not been determined, more prolonged receptor blockade has been associated with increased efficacy. Orally active glycoprotein IIb/IIIa receptor antagonists may be advantageous and required for chronic therapy. METHODS AND RESULTS: Thirty patients with unstable angina who were undergoing percutaneous coronary interventions were randomized to placebo or Xemilofiban 35 mg orally before and 20 to 25 mg TID for 30 days after angioplasty. Bleeding events, platelet aggregation, and pharmacokinetic and hematologic parameters were assessed during hospitalization and at 2 and 4 weeks after drug initiation. Xemilofiban produced a rapid, sustained, marked inhibition of platelet aggregation. ADP-induced platelet aggregation at 2 hours after the initial dose at 2 and 4 weeks was 15%, 8%, and 11% in the Xemilofiban group compared with 80%, 68%, and 69% in the placebo group. Among 20 patients randomized to Xemilofiban there was 1 death after emergency coronary bypass surgery complicated by severe bleeding diathesis, and 3 patients had major bleeding events. Patients on Xemilofiban for 30 days reported episodes of mild mucocutaneous bleeding. CONCLUSIONS: Xemilofiban, an orally active glycoprotein IIb/ IIIa receptor inhibitor, produced rapid, sustained, extensive inhibition of platelet aggregation for a period of up to 30 days. At the dose initially tested, however, acute major bleeding and mucocutaneous bleeding during chronic administration were encountered.

Intravascular ultrasound assessment of the prevalence and causes of angiographic "haziness" following high-pressure coronary stenting.

Haziness at sites of balloon angioplasty is believed to represent plaque fractures or platelet deposition. The etiology of haziness adjacent to coronary stents remains uncertain. This study examines the prevalence and etiology of "peri-stent" haziness following high-pressure deployment. Consecutive patients undergoing coronary stenting and intravascular ultrasound imaging were included. Haziness was defined as nonhomogeneous contrast density and/or indistinct vessel borders by consensus of 2 observers. Patients were excluded if angiography revealed an obvious cause of haziness (thrombus, dissection). Matched control segments without haziness were selected for comparison. The most diseased site within the reference segment was identified by ultrasound. Lumen and plaque areas, percent plaque area, and plaque echo density were assessed. Haziness was identified within 31 segments in 30 patients (15% of 201 angiograms examined). At hazy sites, ultrasound revealed a large percent plaque area in 15, dissections in 14, and near-normal findings in 2 segments. In the absence of dissection, percent plaque area and lumen area step-down from the stent to the diseased reference were greater than controls (percent plaque area 64 +/- 12% vs 56 +/- 10%, p = 0.04 and lumen step-down 35 +/- 20% vs 13 +/- 25%, p = 0.006). With dissections, percent plaque area and lumen step-down were not different from controls (p = 0.13 and 0.30, respectively), but underlying plaques were more frequently echolucent (64% vs 23%, p = 0.02). Thus, in this study, peri-stent haziness was evident in 15% of patients after high-pressure coronary stent deployment. Etiologies identified by intravascular ultrasound included unrecognized reference plaque and angiographically occult dissections.

Late myocardial ischemic events after saphenous vein graft intervention--importance of initially "nonsignificant" vein graft lesions.

Patients undergoing percutaneous coronary revascularization (PCR) for narrowed saphenous vein grafts (SVGs) have a high incidence of subsequent cardiac events, but the relative contribution of treated and untreated SVGs, and of native coronary narrowings to late events is uncertain. This study evaluated the role of progression of SVG disease at untreated sites to cardiac events in these patients. All patients with successful PCR of SVG lesions who were enrolled in clinical trials with mandated repeat angiography from 1990 to 1994 were studied. One hundred three patients (age 63 +/- 8 years, 82% men, ejection fraction 54 +/- 12%, graft age 8 +/- 4 years), contributing 1,095 analyzable 15- to 25-mm SVG segments were followed 29 +/- 13 months (4 patients were lost to follow-up). Actuarial event-free (death, myocardial infarction, bypass surgery, or PCR) and overall survival at 12 months were 47 +/- 5% and 94 +/- 2%, respectively. Fifty-six percent of all early (< or = 12 months) events resulted from ischemia from recurrence at initially treated SVG sites, 26% at nontreated SVG sites, and 14% at nontreated native coronary sites. By 36 months, event-free and overall survival were 25 +/- 6% and 86 +/- 4%, respectively. Events occurring > 12 months after initial treatment resulted most frequently from ischemia from progression of narrowing at untreated SVG sites (46%). Ischemic events from initially untreated SVG sites were correlated with initial percent stenosis (initial, 41% to 50%; 45% events, 31% to 40%; 18% events, < or = 30%; 2% events, p <0.001) and reference SVG diameter (p = 0.003). Recurrent ischemic events from initially treated SVG sites were independently correlated with initial percent stenosis (initial > 75%; 43% events, 50% to 75%; 27% events, < 50%; 18% events, p = 0.01), but not with final percent stenosis. The frequent occurrence of events from nontreated 41% to 50% stenoses suggests a need for increased surveillance in patients with these lesions. The low incidence of events from initially treated lesions < 50% suggests that the hypothesis that "nonsignificant" 41% to 50% lesions might best be treated at the time other more severe narrowings are treated should be examined.

Low-normal or excessive body mass index: newly identified and powerful risk factors for death and other complications with percutaneous coronary intervention.

Recognized risk factors account for only a small portion of the variance in the 4% to 10% incidence of major ischemic events associated with percutaneous coronary intervention. Body mass index (BMI) (body weight in kg/[height in m]2) is a clinically useful estimate of body fat and has been shown to correlate with mortality from several causes. We sought to evaluate the effect of BMI as a potential risk factor for the complications of percutaneous coronary intervention in 3,571 consecutive percutaneous coronary intervention patients treated at a single referral center. Patients were prospectively divided into the nonobese (BMI < or = 25), mildly obese (BMI 26-35), and very obese (BMI > 35), based on accepted definitions. Multiple logistic regression analyses were used to determine the correlates of major complications from 25 candidate variables, including BMI < or = 25 (n = 614 patients) and BMI > 35 (n = 275 patients), recorded prospectively in a relational database. Death occurred in 2.8% of the BMI < or = 25 group, in 3.7% of the BMI > 35 group, and in 0.9% of the BMI 26-34 group (p < 0.001), but there was no difference in the incidence of other ischemic events. Blood product transfusion was required in 12% of the BMI < or = 25 group, in 7% of the BMI 25-34 group, and in 8% of the BMI > 35% group (p = 0.003). Multivariate analysis, after adjustment for other significant correlates, demonstrated that both BMI < or = 25 (odds ratio [OR] = 2.7, p = 0.005) and BMI > 35 (OR = 7.4, p < 0.001) were independent correlates of death. Low-normal or high BMI is a newly described and powerful risk factor for in-hospital death after percutaneous coronary intervention.

The dilemma of diagnosing coronary calcification: angiography versus intravascular ultrasound.

OBJECTIVES: We sought to determine whether careful examination of angiograms in conjunction with other clinical information could reliably detect, quantitate and localize target lesion calcification before a coronary intervention. BACKGROUND: The presence, extent and location of calcium in coronary artery lesions are important determinants of outcome after coronary intervention. Intravascular ultrasound is proposed as a superior technique for identifying patients with coronary artery calcification. However, the precise role of this costly and invasive method has not yet been established. METHODS: Target lesion calcification was assessed in 183 patients (155 men; mean [+/-SD] age 58 +/- 10 years) by angiography and intravascular ultrasound before a planned percutaneous coronary intervention. RESULTS: Ultrasound detected calcium in 138 patients (>90 degrees in 56, 91 degrees to 180 degrees in 52, 181 degrees to 270 degrees in 22 and > 270 degrees in 8), whereas angiography showed calcification in 63 (1+ in 32, 2+ in 27 and 3+ in 4). The two techniques agreed in 92 patients and disagreed in 91. Sensitivity and specificity of angiography were 40% and 82%, respectively. The arc of calcium by ultrasound was greater in patients with angiographically visible calcification (175 degrees +/- 85 degrees vs. 108 degrees +/- 71 degrees, p=0.0001). The depth of calcification by ultrasound was superficial in 61 patients (44%), deep in 68 (49%) and mixed in 8 (7%). The sensitivity of angiography in identifying superficial calcium was 35%. Of 120 patients without angiographically visible calcium at the target lesion site, 83 showed calcium by ultrasound. The only predictor of ultrasound calcium in these 120 patients was angiographic calcification elsewhere in the coronary tree (p=0.0001). The probability of any calcium and superficial >90 degrees calcium were 60% and 12%, respectively, in the 90 patients without angiographic calcifications anywhere in the coronary tree. CONCLUSIONS: Despite poor sensitivity, angiography may help identify patients requiring intravascular ultrasound. When it is angiographically visible, the arc of calcium is likely to be large and superficial. Angiographic calcification at a remote site is a predictor of angiographically undetected target lesion calcium. Patients without angiographic calcification in the coronary tree may not need routine ultrasound examination, as the likelihood of >90 degrees superficial calcium is low.

Early and 1-year survival rates in acute myocardial infarction complicated by cardiogenic shock: a retrospective study comparing coronary angioplasty with medical treatment.

Cardiogenic shock remains a frequently lethal complication of acute myocardial infarction. Early revascularization of the infarct-related artery by coronary angioplasty has been suggested to significantly improve patient survival. In-hospital and 1-year survival was assessed in 50 patients hospitalized for acute myocardial infarction complicated by cardiogenic shock. All patients received medical treatment and intraaortic balloon pump support. Thirty-three patients underwent coronary angioplasty (PTCA group), while 17 patients remained on conventional therapy (no PTCA group). The two groups were comparable for all baseline characteristics. Survival was significantly better in the PTCA group than in the no PTCA group: 64% versus 24% in-hospital survival (p = 0.007) and 52% versus 12% at 1 year (p = 0.006). When angioplasty was successful in achieving reperfusion, survival was further enhanced: in-hospital survival rate was 76% versus 25% in patients with unsuccessful angioplasty and 60% versus 25% at 1 year.

Increased coronary perforation in the new device era. Incidence, classification, management, and outcome.

BACKGROUND: The incidence of coronary perforation using new percutaneous revascularization techniques may be increased compared with PTCA. Still, perforation is uncommonly reported, and the optimal management and expected outcome remain unknown. The objectives of the study were to determine the incidence of coronary perforation using balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) and new revascularization techniques and to develop optimal strategies for its management based on classification and outcome. METHODS AND RESULTS: Eleven sites with frequent use of new revascularization devices and prospective coding of consecutive procedures for coronary perforation during 1990 to 1991 contributed to a perforation registry. Patients with perforation were matched by device with an equal-sized cohort without perforation. Data were collected centrally, and all procedural cineangiograms were reviewed at a core angiographic laboratory. A classification scheme based on angiographic appearance of the perforation (I, extraluminal crater without extravasation; II, pericardial or myocardial blushing; III, perforation > or = 1-mm diameter with contrast streaming; and cavity spilling) was evaluated as a predictor of outcome and as a basis for management. Perforation was observed in 62 of 12,900 procedures reported (0.5%; 95% confidence interval, 0.4% to 0.6%), more commonly with devices intended to remove or ablate tissue (atherectomy, laser) than with PTCA (1.3%, 0.9% to 1.6% versus 0.1%, 0.1% to 0.1%; P < .001). The perforation population was notable for its advanced age (67 +/- 10 years) and high incidence of female sex (46%) (both P < .001 compared with patients without perforation). Perforation could be treated expectantly or with PTCA but without cardiac surgery in 85%, 90%, and 44% of class I, II, and III perforations, respectively. Class I perforations (n = 13, 21%) were associated with death in none, myocardial infarction in none, and tamponade in 8%. The incidences of these adverse events were 0%, 14%, and 13% in class II perforations (n = 31, 50%) and 19%, 50%, and 63% in non-cavity spilling class III perforations, respectively (n = 16, 26%). Two of the 15 instances of cardiac tamponade (13%) were delayed, occurring within 24 hours after dismissal from the catheterization laboratory. CONCLUSION: The incidence of perforation, while low, is increased with new devices. Women and the elderly are at highest risk. The clinical risk after perforation can be classified angiographically, but even low-risk perforations occasionally have poor clinical outcome. Patients should be observed for delayed cardiac tamponade for at least 24 hours.

Cardiac outcome of major noncardiac surgery in patients undergoing preoperative coronary angioplasty.

Patients with significant coronary artery disease are at increased risk for myocardial infarction and death when undergoing major noncardiac surgery, particularly vascular, thoracic and upper abdominal procedures. Revascularization with coronary bypass surgery has shown to be effective in reducing perioperative coronary events in such patients. Little data is available on the role of preoperative coronary angioplasty in this setting. The objective of this study was to determine the perioperative cardiac outcome in patients undergoing coronary angioplasty within six weeks of major noncardiac surgery. We analyzed our experience with 108 consecutive patients (85 males) with a mean age of 68 years (range 41-83) who underwent coronary angioplasty within 42 days of a major operative procedure, which was defined as either a vascular, thoracic or upper abdominal procedure. Multivessel disease was present in 48% of patients. Angioplasty success rate was 97% with 33 (31%) patients having more than one lesion dilated. Angioplasty complications included 1 stroke and 4 non-Q wave myocardial infarctions. The mean time from angioplasty to operative procedure was 14.5 days (range 0-41 days). Ninety six (91%) of the patients underwent vascular surgery--including 42 abdominal aneurysm repairs, 29 carotid endarterectomies, 21 lower extremity bypass operations and four renal artery bypass procedures. Eight patients had major abdominal surgery and one patient had a thoracic procedure. Postoperative cardiac complications included three non-Q wave myocardial infarctions and one Q-wave myocardial infarction which resulted in the only cardiac death (0.9%). There were no sustained ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal angioplasty involving internal mammary artery grafts.

With the increasing use of the internal mammary artery as the conduit of choice in coronary bypass surgery, it is anticipated that an expanding patient population will have stenosis, usually at the site of internal mammary-to-coronary artery anastomosis. In our series 31 patients underwent dilatation at either the site of anastomosis (24), the native coronary artery beyond the anastomosis (4), or both (3) with no mortality, myocardial infarction, or need for emergency coronary artery bypass surgery. Angiographic and clinical success was achieved in 28 patients (90%). There were two internal mammary artery dissections with both patients requiring elective coronary bypass surgery. Of the patients in whom dilatation was successful, 22 (79%) have been followed for longer than 6 months and 19 (86%) have had sustained functional improvement at a mean of 35 months after angioplasty. One patient is to undergo repeat coronary bypass surgery. No patient has had a myocardial infarction or died during follow-up. Although percutaneous transluminal coronary angioplasty of the internal mammary artery has inherent difficulties because of the anatomic characteristics of the vessel, it can be performed with a high degree of primary success and a low incidence of complications and can provide long-term clinical improvement.

Side branch occlusion during coronary angioplasty: incidence, angiographic characteristics, and outcome.

Side branch occlusion (SBO) during percutaneous transluminal coronary angioplasty is a well-recognized complication. The purpose of the present study was to analyze the incidence, angiographic characteristics, and sequelae of side branch occlusion. Data from coronary angiograms of 4,800 consecutive patients from January 1981 to December 1987 was retrospectively analyzed, and 167 patients (3%) involving 181 lesions, with side branch occlusion, were identified. Only arteries with occlusion of side branches greater than 1 mm were evaluated. There were 65 (36%) diagonal, 49 (27%) septal, 40 (22%) left circumflex, and 27 (15%) right coronary branch occlusions. Most side branch occlusion occurred in branches with disease (66%: 120 of 181) or branches originating within the primary arterial lesion (72%: 130 of 181). Although the incidence of side branch occlusion is uncommon, it is associated with a significant incidence of myocardial infarction (14%). Attempts to reopen the occluded branch were successful in 27 of 36 cases (75%). With improvement in balloon angioplasty technology, the risks of side branch occlusion have declined, and many occlusions can be successfully reopened, suggesting that side branch involvement in a primary lesion is not a limitation to balloon angioplasty.