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Biomedical subjects

S G Ellis

Publications and source records attributed to S G Ellis.

At least 73 records · Page 4Linked to original sources
PubMed1999

Clinical risk factors for ischemic complications after percutaneous coronary interventions: results from the EPIC trial. The EPIC Investigators.

BACKGROUND: Most analyses of complications after percutaneous coronary intervention have been limited to angiographic predictors of abrupt closure. We sought to determine the relation between baseline clinical and angiographic characteristics and clinical ischemic events and whether treatment with the platelet glycoprotein IIb/IIIa receptor antagonist c7E3 reduced ischemic events differentially in patients with distinct lesion morphologic characteristics. In the EPIC trial, a bolus and infusion of c7E3 decreased the 30-day incidence of death, myocardial infarction, and need for revascularization by 35% in 2099 high-risk patients. METHODS: We used logistic regression modeling to determine the relations between these patients' baseline clinical and angiographic characteristics and the composite primary end point. We also constructed multivariable models with interaction terms to assess treatment effect on prespecified, core laboratory-assessed, coronary morphologic characteristics. RESULTS: The most important predictors of a poor outcome were low weight (chi-square = 10.5, P =.001) and preprocedural percent stenosis (chi-square = 15.0, P <.001). History of hypertension, nonwhite race, and peripheral vascular disease were also associated with an increased risk, as were all measures of lesion complexity except calcification and presence of a side branch. The treatment benefit with abciximab was significantly greater with less complex than with more complex lesion morphologic characteristics. CONCLUSIONS: Future risk models should include these baseline characteristics to define the risk for ischemic complications in individual patients, and treatment with abciximab should not be predicated on lesion morphologic findings alone.

Abciximab↗
PubMed1998

Reduction in complications of angioplasty with abciximab occurs largely independently of baseline lesion morphology. EPIC and EPILOG Investigators. Evaluation of 7E3 for the Prevention of Ischemic Complications. Evaluation of PTCA To Improve Long-term Outcome with abciximab GPIIb/IIIa Receptor Blockade.

OBJECTIVES: We investigated the hypothesis that abciximab might lead to a differential effect among patients with different lesion morphologies; hence, its cost/benefit ratio would be optimized if it were used selectively on the basis of baseline angiographic findings. BACKGROUND: Major complications of coronary angioplasty occur in 4% to 9% of patients. In the Evaluation of 7E3 for the Prevention of Ischemic Complications (EPIC) and Evaluation of PTCA To Improve Long-term Outcome with abciximab GPIIb/IIIa Receptor Blockade (EPILOG) trials, abciximab decreased the ischemic complications after intervention by 35% to 56%. However, the cost of this agent is appreciable, and there remain concerns about the safety of its readministration. METHODS: There were 1,362 patients in EPIC and 2,792 patients in EPILOG randomized to either bolus plus an infusion of abciximab or placebo, administered with aspirin and heparin at the time of the coronary intervention. Data from these studies were combined, and a differential effect of abciximab in relation to baseline lesion morphology on 30-day risk of death, myocardial infarction or urgent intervention was investigated using the Breslow Day test for statistical interaction. RESULTS: Abciximab consistently reduced the relative risk of complications across all lesion morphologies studied, with the possible exception of patients treated with degenerated saphenous vein grafts (risk with placebo 16.3% vs. risk with abciximab 18.6%, Breslow Day test for interaction, p=0.08). However, the absolute reduction of risk was somewhat greater in patients with more complex B2 or C lesions (7.6% and 5.8%, respectively) than in patients with morphologically simpler A or B1 lesions (3.7% and 3.2%, respectively). CONCLUSIONS: The reduction of early adverse ischemic events associated with angioplasty by abciximab occurs largely independent of pretreatment morphology.

Abciximab↗
PubMed1998

Spectrum of surgical risk for left main coronary stenoses: benchmark for potentially competing percutaneous therapies.

Coronary artery bypass grafting is the preferred therapy for left main trunk coronary stenoses because of a demonstrated survival advantage compared with medical therapy. Recently, however, advocates of percutaneous intervention have suggested that stenting or atherectomy may provide acceptable results for these patients. To determine the spectrum of surgical outcome among patients with left main trunk coronary stenoses, we analyzed 14 potential covariates of in-hospital and 3-year mortality for a consecutive series of patients without prior coronary artery bypass grafting treated at our institution from January 1990 to December 1995. In-hospital mortality (2.3%) for 1585 consecutively treated patients correlated independently with renal dysfunction, age, and class III to IV heart failure. A model was constructed that allowed prediction of outcome (c-statistic = 0.77, p < 0.0001), and only the 9% of patients at highest risk were found to be at risk for death >5%. Mortality at 3 years (15.6%+/-2.2%) in a previously specified subgroup (n = 285) correlated independently with baseline age, renal dysfunction, and chronic pulmonary disease. A model was constructed that allowed prediction of outcome for the validation sample (four risk groups with 3-year mortality rates of 4.5%+/-2.5%, 6.5%+/-2.8%, 20.0%+/-4.2%, and 39.8%+/-8.5%; p < 0.0001. These data provide a contemporary benchmark of clinical outcome against which possible competing therapies may be compared.

Aged↗
PubMed1998

Does intracoronary thrombus influence the outcome of high risk percutaneous transluminal coronary angioplasty? Clinical and angiographic outcomes in a large multicenter trial. EPIC Investigators. Evaluation of IIb/IIIa Platelet Receptor Antagonist 7E3 in Preventing Ischemic Complications.

OBJECTIVES: We sought to evaluate the impact of angiographically visible thrombus on short- and long-term clinical outcomes after percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: Intracoronary thrombus is frequently seen on angiography in patients with acute ischemic coronary syndromes or complex lesion morphology, or both, and is often considered to predict a higher rate of complications in patients undergoing PTCA. METHODS: Prospectively collected data from 2,099 patients undergoing high risk PTCA in the Evaluation of IIb/IIIa Platelet Receptor Antagonist 7E3 in Preventing Ischemic Complications (EPIC) trial were analyzed. In addition to aspirin and heparin, patients were randomized to receive either abciximab bolus and infusion, abciximab bolus alone or placebo. Based on an angiographic core laboratory interpretation, patients were classified into three groups: thrombus absent, thrombus possible or thrombus present. The primary end point at 30 days was the composite of death, myocardial infarction or urgent revascularization. The 6-month end point was the composite of death, myocardial infarction or any revascularization. RESULTS: Although abrupt closure was most common in patients with thrombus present compared with thrombus absent or possible (13%, 10.0% and 7.4%, respectively), neither the 30-day nor the 6-month clinical end points were different among the three groups (9%, 11% and 11.7%, respectively, and 30%, 34% and 31%, respectively). Most notably, the benefit of treatment with abciximab was present in all three thrombus groups, and the magnitude of benefit was not different among the thrombus groups. CONCLUSIONS: In high risk patients undergoing percutaneous coronary revascularization, features of thrombus on the preprocedure angiogram do not indicate an augmented risk of adverse clinical outcomes. Abciximab therapy reduces the rate of adverse outcomes regardless of the presence of thrombus and should therefore not necessarily be reserved for patients whose angiograms have features of intraluminal thrombus.

Abciximab↗
PubMed1998

Cost of cardiac care in the three years after coronary catheterization in a contained care system: critical determinants and implications.

OBJECTIVES: We sought to determine the clinical, angiographic, treatment and outcome correlates of the intermediate-term cost of caring for patients with suspected coronary artery disease (CAD). BACKGROUND: To adequately predict medical costs and to compare different treatment and cost reduction strategies, the determinants of cost must be understood. However, little is known about the correlates of costs of treatment of CAD in heterogeneous patient populations that typify clinical practice. METHODS: From a consecutive series of 781 patients undergoing cardiac catheterization in 1992 to 1994, we analyzed 44 variables as potential correlates of total (direct and indirect) in-hospital, 12- and 36-month cardiac costs. RESULTS: Mean (+/-SD) patient age was 65+/-10 years; 71% were men, and 45% had multiple vessel disease. The initial treatment strategy was medical therapy alone in 47% of patients, percutaneous intervention (PI) in 30% and coronary artery bypass graft surgery (CABG) in 24%. The 36-month survival and event-free (death, infarction, CABG, PI) survival rates were 89.6+/-0.2% and 68.4+/-0.4%, respectively. Median hospital and 36-month costs were $8,301 and $28,054, respectively, but the interquartile ranges for both were wide and skewed. Models for log(e) costs were superior to those for actual costs. The variances accounted for by the all-inclusive models of in-hospital, 12- and 36-month costs were 57%, 60% and 71%, respectively. Baseline cardiac variables accounted for 38% of the explained in-hospital costs, whereas in-hospital treatment and complication variables accounted for 53% of the actual costs. Noncardiac variables accounted for only 9% of the explained costs. Over time, complications (e.g., late hospital admission, PI, CABG) and drug use to prevent complications of heart transplantation became more important, but many baseline cardiac variables retained their importance. CONCLUSIONS: 1) Variables readily available from a comprehensive cardiovascular database explained 57% to 71% of cardiac costs from a hospital perspective over 3 years of care; 2) the initial revascularization strategy was a key determinant of in-hospital costs, but over 3 years, the initial treatment become somewhat less important, and late complications became more important determinants of costs.

Aged↗
PubMed1998

The duration of pretreatment with ticlopidine prior to stenting is associated with the risk of procedure-related non-Q-wave myocardial infarctions.

OBJECTIVES: This study sought to determine whether the duration of pretreatment with the adenosine diphosphate receptor antagonist ticlopidine prior to intracoronary stenting is associated with the incidence of procedure-related non-Q-wave myocardial infarctions (MIs). BACKGROUND: Dual antiplatelet therapy with ticlopidine and aspirin is routinely used with stenting, although ticlopidine is commonly not begun until the day of the procedure. Periprocedural MIs are at least partially platelet-dependent events. As the maximal platelet inhibitory effects of this drug take 2 to 3 days to be realized, we hypothesized that longer treatment prior to stenting would be associated with lower rates of procedure-related MIs. METHODS: We reviewed outcomes in 175 consecutive patients treated with ticlopidine prior to stenting at the Cleveland Clinic Foundation. Those patients with an elevation in creatine kinase above our laboratory normal (>210 IU/L) with > or =4% MB fraction on routine evaluation were defined as having a non-Q-wave MI. RESULTS. There were 28 patients (16%) who had a non-Q-wave MI. Longer duration of ticlopidine pretreatment was strongly associated with a lower incidence of procedure-related non-Q-wave MIs (duration of pretreatment <1 day, 29% had MI; 1 to 2 days, 14%; > or =3 days, 5%; chi-square for trend=9.6; p=0.002). Ticlopidine pretreatment of > or =3 days was associated with a significant reduction in the risk of non-Q-wave MI (unadjusted odds ratio 0.18, 95% confidence interval=0.04 to 0.78, p=0.01) compared with pretreatment of <3 days. CONCLUSIONS: Among patients undergoing intracoronary stenting, beginning ticlopidine therapy several days prior to the procedure is associated with a reduced risk of procedural non-Q-wave MIs.

Blood Vessel Prosthesis Implantation↗
PubMed1998

Rescue percutaneous transluminal coronary angioplasty.

Fibrinolytic therapy for acute myocardial infarction, even with the most efficient regimens available, is fraught with a substantial proportion of failures to reopen the occluded vessel. The term rescue percutaneous transluminal coronary angioplasty (PTCA) has been introduced to describe an attempt to mechanically recanalize the infarct vessel if fibrinolytic reperfusion fails. Despite the intuitive appeal and widespread use of rescue PTCA, only a limited amount of data (mostly observational retrospective data) is available to confirm the clinical benefit of this therapeutic option.

Angioplasty, Balloon, Coronary↗
PubMed1998

Prevention of in-stent restenosis.

Despite the favourable impact of stent implantation on restenosis rates for selected lesion types, in-stent restenosis remains a commonly encountered and difficult to manage entity. Histologically, in-stent restenosis appears to derive almost exclusively from neointimal hyperplasia, which appears to be more abundant following stent implantation than balloon angioplasty. The most powerful predictors of in-stent restenosis include the presence of diabetes, greater lesion length, small vessel caliber, and inadequate stent expansion. Several strategies have been proposed as a means to reduce the incidence of in-stent restenosis. Perhaps the most important among these relates to a strategy of provisional stent use, whereby stenting is undertaken only if suboptimal results are achieved following balloon angioplasty. Recent data from the EPILOG and EPILOG-stent trials suggest that the use of IIb/IIIa receptor antagonists may enhance the strategy of provisional stenting. When stents are used, adequate deployment is essential. The ability of adjunct IVUS imaging to guide proper balloon sizing during stent implantation and consequently reduce the risk of restenosis is currently the subject of randomized trials. Based on preliminary study results, intravascular radiation appears to hold great potential as a means to inhibit neointimal hyperplasia and consequently reduce the occurrence of in-stent restenosis, and large scale safety and efficacy trials are in progress. Other pharmacologic- and device-oriented strategies are likewise undergoing evaluation. In conclusion, while the availability of coronary stents has without question improved the safety and efficacy of coronary angioplasty, it remains critical that we continue to determine in an objective manner how and when best to use these devices.

Angioplasty, Balloon, Coronary↗
PubMed1997

Contemporary percutaneous treatment of unprotected left main coronary stenoses: initial results from a multicenter registry analysis 1994-1996.

BACKGROUND: Coronary artery bypass surgery (CABG) has been considered the therapy of choice for patients with unprotected left main (ULMT) coronary stenoses. Selected single-center reports suggest that the results of percutaneous intervention may now approach those of CABG. METHODS AND RESULTS: To assess the results of percutaneous ULMT treatment from a wide variety of experienced interventional centers, we requested data on consecutive patients treated after January 1, 1994, from 25 centers. One hundred seven patients were identified who were treated either electively (n=91) or for acute myocardial infarction (n=16). Of patients treated electively, 25% were considered inoperable, and 27% were considered high risk for bypass surgery. Primary treatment included stents (50%), directional atherectomy (24%), and balloon angioplasty (20%). Follow-up was 98.8% complete at 15+/-8 months. Results varied considerably, depending on presentation and treatment. For patients with acute myocardial infarction, technical success was achieved in 75%, and survival to hospital discharge was 31%. For elective patients, technical success was achieved in 98.9%, and in-hospital survival was strongly correlated with left ventricular ejection fraction (P=.003). Longer-term event (death, infarction, or bypass surgery) -free survival was correlated with ejection fraction (P<.001) and was inversely related to presentation with progressive or rest angina (P<.001). Surgical candidates with ejection fractions > or = 40% had an in-hospital survival of 98% and a 9-month event-free survival of 86+/-5%, whereas patients with ejection fractions < 40% had 67% and 22+/-12% in-hospital and 9-month event-free survivals, respectively. Nine hospital survivors (10.6%) experienced cardiac death within 6 months of hospital discharge. CONCLUSIONS: While results for selected patients appear promising, until early post-hospital discharge cardiac death can be better understood and minimized, percutaneous revascularization of ULMT stenosis should not be considered an alternative to bypass surgery for most patients. When percutaneous revascularization of ULMT is required, directional atherectomy and stenting appear to be the preferred techniques, and follow-up angiography 6 to 8 weeks after treatment is probably advisable.

Aged↗
PubMed1997

Long-term protection from myocardial ischemic events in a randomized trial of brief integrin beta3 blockade with percutaneous coronary intervention. EPIC Investigator Group. Evaluation of Platelet IIb/IIIa Inhibition for Prevention of Ischemic Complication.

CONTEXT: Abciximab, a monoclonal antibody fragment against the platelet receptor alphaIIb beta3 integrin, prevents platelet aggregation. A randomized, placebo-controlled study showed that abciximab improves outcomes for patients undergoing percutaneous coronary angioplasty at 30 days and at 6 months. OBJECTIVE: To determine whether abciximab improves outcomes 3 years after coronary angioplasty. DESIGN: Double-blind, placebo-controlled, randomized trial. SETTING: A total of 56 academic and community hospitals in the United States. PATIENTS: A total of 2099 high-risk patients undergoing coronary angioplasty were randomized. Sufficient time elapsed for 2.5 years of follow-up among 2001 patients and for 3 years of follow-up among 1599 patients. INTERVENTIONS: Abciximab bolus of 0.25 mg/kg followed by infusion at 10 microg/min for 12 hours; abciximab bolus of 0.25 mg/kg followed by placebo infusion; or placebo bolus followed by placebo infusion. MAIN OUTCOMES MEASURES: The primary outcome was the composite of death, myocardial infarction, or coronary revascularization. Secondary outcomes were death, myocardial infarction, or coronary revascularization individually. Subgroups having refractory unstable angina or evolving myocardial infarction and having different elevations of creatine kinase during initial angioplasty were analyzed. RESULTS: At 3 years, composite end points occurred in 41.1% of those receiving abciximab bolus plus infusion; 47.4% of those receiving abciximab bolus only; and 47.2% of those receiving placebo only (for abciximab bolus plus infusion vs placebo, P=.009). Death occurred in 6.8%, 8.0%, and 8.6%, respectively (for abciximab bolus plus infusion vs placebo, P=.20); myocardial infarction in 10.7%, 12.2%, and 13.6%, respectively (for abciximab bolus plus infusion vs placebo, P=.08); and revascularization in 34.8%, 38.6%, and 40.1%, respectively (for abciximab bolus plus infusion vs placebo, P=.02). Among those with refractory unstable angina or evolving myocardial infarction, death occurred in 5.1%, 9.2%, and 12.7%, respectively (for abciximab bolus plus infusion vs placebo, P=.01). Death rates increased as periprocedural creatine kinase levels increased. CONCLUSIONS: Abciximab bolus with infusion given at the time of coronary angioplasty improves outcomes as long as 3 years after the procedure.

Abciximab↗
PubMed1997

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.

Aged↗
PubMed1997

End-systolic volume index at 90 to 180 minutes into reperfusion therapy for acute myocardial infarction is a strong predictor of early and late mortality. The Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I Angiographic Investigators.

BACKGROUND: Left ventricular remodeling is an important sequela of myocardial infarction (MI). Although remodeling occurs soon after MI, the effect of early left ventricular dilatation on outcome is not established and may be useful for early risk stratification. We assessed whether end-systolic volume index (ESVI) at 90 to 180 minutes into thrombolytic therapy for MI is associated with adverse outcomes. METHODS AND RESULTS: In the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I study, 41021 patients with evolving MI received one of four thrombolytic regimens. At 90 or 180 minutes into reperfusion therapy, 1300 patients underwent left ventriculography. ESVI was measured and correlated with adverse outcomes: 30-day and 1-year mortality and in-hospital congestive heart failure, shock, and reinfarction. Clinical variables were also tested in a stepwise logistic regression analysis to determine predictors of left ventricular dilatation. ESVI was directly related to all adverse outcomes with univariate analysis. ESVI of > or = 40 mL/m2 was independently associated with mortality (adjusted odds ratio [95% confidence interval]: 30-day, 3.4 [2.0 to 5.9]; 1-year, 4:1 [2.6 to 6.2], both P < .001). Male sex, prior angina or MI, weight of < 70 kg, heart rate of > or = 80 bpm, systolic blood pressure of < 110 mm.Hg, and anterior infarction were independent predictors of an ESVI of > or = 40 mL/m2. CONCLUSIONS: Left ventricular ESVI early into reperfusion therapy for MI strongly predicts adverse outcomes, including early and late mortality. The study establishes the role of very early left ventricular dilatation on outcome in MI and may be useful in identifying high-risk patients who might benefit from aggressive treatment, including the early use of ACE inhibitors.

Aged↗