Predicting the risk of abrupt vessel closure after angioplasty in an individual patient

The factors influencing the efficiency of drug-coated balloons

The drug-coated balloon (DCB) is an emerging percutaneous coronary intervention (PCI) device that delivers drugs to diseased vessels to decrease the rate of vascular stenosis. Recent clinical studies have demonstrated that DCBs tend to have both good safety and efficacy profiles, leading to extended application indications in the clinic, including in-stent restenosis (ISR) for metal stents such as drug-eluting stents (DESs), small vascular disease, bifurcation disease, large vascular disease, acute coronary syndrome (ACS), and high bleeding risk. However, some previous clinical data have suggested that DCBs performed less effectively than DESs. No studies or reviews have systematically discussed the improvement strategies for better DCB performance until now. Drug loss during the process of delivery to the target lesion and inefficient delivery of the coating drug to the diseased vascular wall are two key mechanisms that weaken the efficiency of DCBs. This review is the first to summarize the key influencing factors of DCB efficiency in terms of balloon structure and principles, and then it analyzes how these factors cause outcomes in practice based on current clinical trial studies of DCBs in the treatment of different types of lesions. We also provide some recommendations for improving DCBs to contribute to better DCB performance by improving the design of DCBs and combining other factors in clinical practice.

Comparing efficacy of receiving different dosages of eptifibatide in bleeding after percutaneous coronary intervention in patients with myocardial infarction

BACKGROUND

Acute coronary syndrome (ACS) is a common condition that needs appropriate treatment like percutaneous coronary intervention (PCI). Glycoprotein IIb/IIIa inhibitors (GPI) like eptifibatide prevent procedural ischemic complications after PCI. Eptifibatide has increased the risk of bleeding complications, although it is effective in reducing mortality and morbidity. Eptifibatide is routinely used in bolus and infusion forms and the aim of this study is to evaluate the efficacy of bolus-only dose and bolus + infusion strategy for administrating eptifibatide in bleeding complications and consequences after PCI.

METHODS

This randomized clinical trial was conducted on subjects who experienced PCI after incidence of myocardial infarction (MI). Patients were randomly divided into two groups who received bolus-only dose (n = 51) or bolus + infusion form of eptifibatide (n = 50). Then, PCI blood pressure, mean time duration of hemostasis after arterial sheath removal, laboratory data, need for blood transfusion, and presence of bleeding complications were evaluated. After 6 months, patients were followed for needs for additional coronary interventions.

RESULTS

The mean age of participants was 61.68 ± 1.50 years. The prevalence of men was 70.29%. There was no significant difference in mean of systolic blood pressure (SBP) and diastolic blood pressure (DBP) during hospitalization (P > 0.050). The mean time duration of hemostasis was 8.13 ± 0.45 minutes in the bolus-only group and 16.46 ± 0.71 minutes in the bolus + infusion group (P < 0.001). There was no significant difference in the hemoglobin (Hb) level, platelet count, white blood cell (WBC), blood urea nitrogen (BUN), and creatinine level (P > 0.050).

CONCLUSION

The results of this study suggested that bolus-only dose of eptifibatide before PCI could be able to decrease significantly bleeding complication and other clinical and cardiovascular outcomes.

Role of Intracoronary Fibrinolytic Therapy in Contemporary PCI Practice

Plaque rupture or plaque erosion leads to intracoronary thrombus formation resulting in coronary artery occlusion and ST-segment elevation myocardial infarction. Early restoration of blood flow in occluded coronary artery is the mainstay of therapy and it can be achieved by either thrombolytic therapy or primary percutaneous coronary intervention (P-PCI) or a combination of these two in many different ways. It has been proved that primary PCI is better than thrombolytic therapy in establishing early and effective recanalization of infarct related artery, reducing major adverse cardiovascular events (MACE) and increasing survival. There have been tremendous advances in PCI techniques over the years with newer stents, thrombectomy devices, and adjunctive pharmacotherapy. However, intracoronary thrombus continues to be the bane of interventional cardiologists. Failure of recanalization, suboptimal results, distal embolization, no reflow and impaired myocardial perfusion are some of the unresolved difficulties, regularly seen during PCI of patients with large intracoronary thrombus burden indicating an unmet need. This review focuses on emerging evidence about the usefulness of intracoronary thrombolytic therapy as an adjunct to PCI in patients with large intracoronary thrombus burden.

New approaches to long lesions

Long coronary lesions, comprising up to 20% of the interventional practice, pose a significant challenge to the interventionalist. Several approaches have been described to treat long coronary lesions with long-term suboptimal outcomes. Atherectomy and laser treatments with or without adjunctive balloon angioplasty have not been shown to be superior to conventional balloon angioplasty alone. Preliminary data with the use of drug-eluting stents in the treatment of long coronary lesions appears to be promising even in small vessels and may eventually become the mainstay treatment of long lesions.

Controversies surrounding the use of glycoprotein IIb/IIIa inhibitors

The use of glycoprotein IIb/IIIa inhibitors reduces morbidity and mortality in patients with acute coronary syndromes and patients undergoing percutaneous coronary intervention. Despite the sound body of evidence that supports the use of these agents, registry data indicate that there is substantial underuse in eligible patients. This may be due to their modest treatment effect, controversy over the significance of reductions in recurrent myocardial infarction, or confusion over appropriate combinations of antiplatelet and antithrombin agents. The challenge for clinicians is to identify patients that receive the most benefit from the use of glycoprotein IIb/IIIa inhibitors. Until the results of ongoing trials become available, the American College of Cardiology/American Heart Association guidelines provide reasonable recommendations on the use of these agents in clinical practice.

Long-term clinical benefits of a platelet glycoprotein IIb/IIIa receptor blocker, abciximab (ReoPro), in high-risk diabetic patients undergoing percutaneous coronary intervention

BACKGROUND

High-risk percutaneous coronary interventions (PCIs) are associated with a high complication rate, a low procedural success rate and a high restenosis rate, especially in diabetics. We sought to determine whether abciximab (ReoPro) therapy affects long-term clinical outcomes of Korean patients with diabetes undergoing high-risk PCI.

METHODS

One hundred and nineteen patients with 152 lesion sites were administered ReoPro among 2,231 patients who underwent PCI at Chonnam National University Hospital from March 1999 to Feb 2001. These 119 patients were divided into two groups, 30 were allocated to a diabetic group (Group 1, 57.7 +/- 8.2 years, 22 male), and 89 to a non-diabetic group (Group II, 59.6 +/- 10.8 years, 68 male). Early and long-term clinical outcomes after PCI were analyzed.

RESULTS

In terms of clinical diagnosis, the number of acute myocardial infarctions in Group I was 25 (83.3%) and 76 in Group II (85.4%). As for risk factors, target artery lesions, and ACC/AHA types, no differences were found between the two groups. The number of patients with total occlusion was 21 (55.3%) and 62 (53.9%), and the number with a thrombus-containing lesion was 28 (93.3%) and 88 (98.9%) in Groups I and II, respectively. The procedure was successful in 27 (90.0%) in Group I, and in 80 (89.9%) in Group II, and no differences were evident between the two groups in terms of bleeding complications. No major adverse cardiac events (MACE), including myocardial infarction, repeat revascularization or cardiac death, were observed in Group I, but 8 cases of MACE occurred in Group II during hospitalization. Clinical follow-up was performed in 116 patients (97.5%) over 18.5 +/- 6.7 (5-28) months. The number of overall MACEs was 10 (3.3%) in Group I and 14 (15.7%) in Group II (p = 0.038).

CONCLUSION

ReoPro used in high-risk PCI in diabetics was effective in terms of early clinical outcomes, but its long-term clinical benefits were not proven.

Predictors of subacute stent thrombosis: results of a systematic intravascular ultrasound study

BACKGROUND

Factors leading to subacute stent thrombosis after percutaneous coronary intervention (PCI) have not been well established. We assessed the pre- and post-PCI intravascular ultrasound (IVUS) characteristics of subacute stent thrombosis.

METHODS AND RESULTS

We analyzed 7484 consecutive patients without acute myocardial infarction who were treated with PCI and stenting and underwent IVUS imaging during the intervention. Twenty-seven (0.4%) had angiographically documented subacute closure <1 week after PCI (median time to subacute closure, 24 hours). Subacute closure lesions were compared with a control group (selected to be 3 times the abrupt closer group) matched by procedure date (within 6 months), age, gender, stable or unstable angina, lesion location, and additional treatment (balloon angioplasty or atherectomy). Postintervention IVUS did not identify a cause in 22% and did identify at least 1 cause for abrupt closure in 78% of patients (versus 33% in matched lesions, P=0.0002). In 48% of the patients, there were multiple causes in 48% (versus 3% in matched lesions, P<0.0001). Causes included dissection (17%), thrombus (4%), and tissue protrusion within the stent struts leading to lumen compromise lumen (4%). A total of 83% of patients with >1 of these abnormal morphologies also had reduced lumen dimensions post-PCI (final lumen <80% reference lumen). Preprocedural lesion characteristics were not different from matched lesions.

CONCLUSIONS

Subacute stent thrombosis is infrequently related to the preintervention lesion characteristics. Inadequate postprocedure lumen dimensions, alone or in combination with other procedurally related abnormal lesion morphologies (dissection, thrombus, or tissue prolapse), contribute to this phenomenon.

Safety and efficacy of treatment with platelet GPIIb/IIIa receptor blockade in unstable angina patients awaiting PTCA at a referring clinic

BACKGROUND: Although balloon angioplasty has assumed an important role in the management of refractory unstable angina (UA), that is, UA that does not respond to conventional therapy, it is limited by complications related to thrombosis and acute coronary occlusion. The complication rate is higher in patients with UA than in those whose condition is stable. Preprocedural use of abciximab, a monoclonal platelet glycoprotein IIb/IIIa receptor blocker, has been used effectively in patients with UA, but its acceptance may be limited by safety concerns and economic constraints. The current trial investigated a protocol for abciximab pretreatment in patients with UA awaiting transfer from referring hospitals to a site of intervention (the 'drip and ship' protocol). AIMS: This observational study was conducted to evaluate whether a prophylactic, preprocedural regimen of abciximab can be safely and effectively administered to UA patients in referring hospitals while awaiting coronary angioplasty at the interventional clinic. METHODS: From April 1996 to December 1998, 168 consecutive patients with refractory UA (Braunwald class II or III) received abciximab prospectively at the referring clinic before undergoing PTCA or stent implantation at the interventional clinic. The following cost-conscious protocol was used: a 0.25 mg/kg bolus of abciximab followed by 10 micro g/min intravenously for 16 hours, in addition to intravenous nitrates, heparin and aspirin therapy. Patients were then transferred to a facility with PTCA capability via high-speed ambulance transport. No specific alterations of routine-transfer protocol were needed. Platelet aggregation studies were conducted during abciximab infusion. All interventions were performed while abciximab was given. Procedural and clinical success and long-term outcomes also were assessed. RESULTS: The primary angiographic success rate (patients with post-PTCA diameter stenosis < 50%) was 98%, and the in-hospital clinical success rate (angiographic success without major complications) was 98%. No major bleeding complications occurred during the abciximab pretreatment period. Platelet aggregation findings in the study patients showed a stable inhibition of >80% at the time of angioplasty. At 30-day follow-up, all patients were alive and 91% were free of major adverse events. Outcomes of balloon angioplasty and stenting were equally favorable, indicating no device-specific effect. Event-free survival at six months was 89% with a target vessel revascularization rate of 10%. CONCLUSION: Abciximab was administered safely and effectively to angioplasty patients with refractory UA awaiting transfer from a noninterventional setting to the site of angioplasty. These results extend the current knowledge base that has been established in randomized trials performed in interventional centers. The study protocol potentially could make abciximab therapy more feasible economically, and therefore more widely available to patients who are most likely to benefit from prophylactic administration.

Fracture of cutting balloon microsurgical blade inside coronary artery during angioplasty of tough restenotic lesion: a case report

We report a rare complication due to fracture of the blade of a cutting balloon in the setting of a tough nondilatable restenotic lesion. This resulted in a mural hematoma as a result of dissection of coronary artery.

Role of target vessel size and body surface area on outcomes after percutaneous coronary interventions in women

BACKGROUND

Women have higher mortality rates than men after coronary angioplasty. Differences in target vessel size may partially account for these differences. We set out to explore the effects of sex, body surface area (BSA), and target coronary vessel size on clinical outcomes after angioplasty.

METHODS

Data from 5 interventional trials and 1 registry were pooled for analysis (n = 3982).

RESULTS

Compared with men, women undergoing angioplasty were older, had lower weights and BSA, more coronary risk factors, and slightly smaller target coronary vessel size (as assessed by reference vessel diameter). The correlation between target vessel size and BSA was poor (r = 0.13). At 6 months, women had higher mortality rates (1.7% vs 0.8%, P =.03) but similar rates of myocardial infarction and repeat revascularization. On univariate analysis, advanced age, smaller BSA, and female sex were associated with increased mortality, but target vessel size was not. Advanced age was the only significant multivariate predictor of mortality. Target vessel size and diabetes were independent predictors of repeat revascularization.

CONCLUSIONS

Women have higher unadjusted 6-month mortality rates after angioplasty, owing largely to their more advanced age at the time of intervention. Smaller target vessel size is associated with increased risk of restenosis and repeat revascularization; however, it does not appear to be a predictor for downstream mortality. As such, the fact that women have smaller vessels does not account for their higher 6-month mortality after coronary angioplasty.

Influence of coronary thrombus on outcome of percutaneous coronary angioplasty in the current era (the Mayo Clinic experience)

Earlier studies documented an increased risk of percutaneous coronary intervention (PCI) in patients with angiographic evidence of thrombus. With newer antiplatelet agents and stents, it is not known whether thrombus is a risk factor after PCI. This study examines whether outcome of PCI in patients with thrombus has improved, and whether thrombus is associated with adverse outcome after PCI in the current era. This single-institution retrospective analysis of PCI in 7,184 patients was divided into 2 periods: group I, 1990 to 1995 (n = 3,640), and group II, 1996 to 1999 (n = 3,544). The groups were subdivided according to the presence or absence of angiographic thrombus before PCI. We compared the outcome of PCI for patients with and without thrombus in group II. A comparison was made in the 2 groups in patients with angiographic thrombus. Procedural success improved in group II compared with group I patients with thrombus (93% vs 88%, p <0.001). There was significant reduction in abrupt closure in the recent era in patients with thrombus (4% vs 7%, p = 0.01). In group II, procedural success remained lower in patients with (93% vs 96%) than without thrombus (p <0.001). After adjusting for the significant univariate characteristics of group II patients, thrombus remained an independent predictor of Q-wave infarction (odds ratio 3.78; 95% confidence interval [CI], 1.8 to 8.0; p <0.0013) and the composite end point of death, Q-wave infarction, and emergency bypass surgery (odds ratio 2.37; 95% CI 1.4 to 4.1; p = 0.002). There was a trend toward increased in-hospital death among patients with thrombus (odds ratio 2.06; 95% CI 0.9 to 4.8; p = 0.09). The 1-year outcome after successful PCI was similar for those with and without thrombus. Despite improvement in the outcome of patients with thrombus undergoing PCI in recent years, thrombus is still an independent predictor of adverse in-hospital outcomes after PCI.

Does the presence of thrombus seen on a coronary angiogram affect the outcome after percutaneous coronary angioplasty? An Angiographic Trials Pool data experience

OBJECTIVES

This study aimed to determine whether pre-existing angiographic thrombus was associated with adverse in-hospital and six-month outcomes after percutaneous coronary interventions.

BACKGROUND

There are conflicting data about whether pre-existing thrombus is an independent predictor of adverse in-hospital and short-term outcome after coronary interventions.

METHODS

The Angiographic Trials Pool, a data set derived from eight prospective randomized trials, was analyzed. The study population consisted of 7,917 patients who underwent coronary interventions between 1986 and 1995. Two trials were excluded because they did not collect information regarding thrombus. Patients from the other six trials were divided on the basis of the presence or absence of thrombus.

RESULTS

In patients with (n = 2,752) and without (5,165) thrombus, in-hospital mortality following angioplasty was low (0.8 vs. 0.6%, p = 0.207). Several adverse outcomes were higher in patients with thrombus: death/myocardial infarction (8.4 vs. 5.5%, p < or = 0.001), in-hospital abrupt closure (5.9 vs. 3.9%, p < or = 0.001) and an in-hospital composite of death, myocardial infarction and/or repeat revascularization (15.4 vs. 11.2%, p < or = 0.001). Six-month mortality was low and comparable between the two groups (2.1 vs. 1.8%, p = 0.34), but the incidence of six-month death/myocardial infarction was higher in patients with thrombus (11.7 vs. 8.7%, p < or = 0.0001).

CONCLUSIONS

Percutaneous coronary angioplasty can be performed with low mortality in patients with pre-existing thrombus, although these patients are at higher risk of in-hospital and six-month death/myocardial infarction. Continued efforts are required to optimize the outcome in these high risk patients.

Urgent coronary bypass surgery for failed percutaneous coronary intervention in the stent era: Is backup still necessary?

BACKGROUND

Current practice guidelines for performance of percutaneous coronary intervention (PCI) in the United States mandate availability of on-site surgical backup. With the decreasing frequency of urgent coronary bypass surgery (UCABG) with newer technologies, it is unclear whether such backup continues to be necessary.

METHODS

A database of 5655 consecutive patients undergoing PCI at a single center between August 1, 1992, and December 31, 1997, was analyzed. Outcomes were determined as well as clinical, lesion, and procedural characteristics of patients during 4 time periods preceding and during use of coronary stenting.

RESULTS

Frequency of UCABG for failed PCI decreased from 2.2% to 0.6% in the most recent time period (P <.01) with no change in incidence of in-hospital death or myocardial infarction. Incidence of stenting progressively increased to 72% in the latest period. Patients requiring UCABG had a higher prevalence of acute coronary syndromes (95%) and type B lesions (79%), but these characteristics were also common in patients who did not undergo UCABG. Although coronary stents were available during the last 3 periods studied, only 30% of UCABG patients had lesions or complications amenable to stenting, and stenting attempts in these patients were all unsuccessful. Despite stenting and use of perfusion balloons and intra-aortic balloon pumps, only 40% of patients having UCABG were stable and pain free on transfer to the operating room.

CONCLUSIONS

Although use of UCABG for a failed PCI is currently very low, there are no satisfactory predictors, patients requiring UCABG are frequently clinically unstable, and availability of stenting does not reliably eliminate the need for UCABG or result in a decrease in mortality. This small group of patients continues to require readily available surgical standby.

Pharmacodynamics and safety of lefradafiban, an oral platelet glycoprotein IIb/IIIa receptor antagonist, in patients with stable coronary artery disease undergoing elective angioplasty

OBJECTIVE

Lefradafiban is the orally active prodrug of fradafiban, a glycoprotein IIb/IIIa receptor antagonist. The present phase II study aimed to determine the dose of lefradafiban that provides 80% blockade of the glycoprotein IIb/IIIa receptors by fradafiban, and to study the pharmacodynamics and safety of different doses in patients with stable angina undergoing angioplasty.

DESIGN

A double blind, placebo controlled, dose finding study.

SETTING

Four academic and community hospitals in the Netherlands.

PATIENTS

64 patients with stable coronary artery disease undergoing elective percutaneous transluminal coronary angioplasty.

INTERVENTIONS

30 mg, 45 mg, and 60 mg of lefradafiban three times daily or placebo was given for 48 hours.

MAIN OUTCOME MEASURES

The primary safety end point was the occurrence of bleeding, classified as major, minor, or insignificant according to the thrombolysis in myocardial infarction (TIMI) criteria. Efficacy indices included per cent fibrinogen receptor occupancy (FRO), ex vivo platelet aggregation, and plasma concentrations of fradafiban.

RESULTS

Administration of lefradafiban 30, 45, and 60 mg three times daily resulted in a dose dependent increase in median FRO levels of 71%, 85%, and 88%, respectively. Inhibition of platelet aggregation was closely related to FRO. There were no major bleeding events. The 60 mg lefradafiban group had a high (71%) incidence of minor and insignificant bleeding. The incidence of bleeding was 44% in the 30 mg and 45 mg groups, compared with 9% in placebo patients. Puncture site bleeding was the most common event. The odds of bleeding increased by 3% for every 1% increase in FRO.

CONCLUSIONS

Lefradafiban is an effective oral glycoprotein IIb/IIIa receptor blocker. The clinical effectiveness of doses up to 45 mg three times daily should be investigated.

ABC stenosis morphology classification and outcome of coronary angioplasty: reassessment with computing techniques

BACKGROUND

The American College of Cardiology/American Heart Association (ACC/AHA) stenosis morphology classification (MC) stratifies coronary lesions for probability of success and complications after coronary angioplasty (PTCA). Modern computing techniques were used to evaluate the individual predictive value of MC in random PTCA cases.

METHODS AND RESULTS

MC was attributed to the target lesions by consensus of 2 observers. The predictive value regarding procedural success (PS) and major adverse cardiac events (MACE) of MC was analyzed by conventional logistic regression analyses and by inductive machine learning models. The study was adequately powered for the methods applied with 325 target lesions of 250 cases. Overall, PS decreased and MACE increased from type A to type C lesions. Regression analysis identified no single factor as predictive. Logistic regression showed an error rate of 42%. Machine learning techniques achieved an individual predictive error of only 10%, which could be further reduced to 2% by addition of parameters. For PS, MC parameters showed a high ranking for building the model. For MACE, variables of the medical history showed more impact.

CONCLUSIONS

MC per se cannot individually predict PS or MACE. However, when all MC parameters are integrated together with additional lesion-specific and history variables, a high individual predictive value can be achieved. This technique may be clinically helpful for risk stratification in the catheterization laboratory and improvement of classification systems in interventional cardiology.

European criteria for the appropriateness and necessity of coronary revascularization procedures

OBJECTIVES

Large variations in the use of coronary revascularization procedures have led many countries to apply the RAND appropriateness method to develop specific criteria describing patients who should be offered these procedures. The method is based on the work of a multidisciplinary expert panel that reviews a synthesis of the scientific evidence and rates the appropriateness of a comprehensive list of indications for the procedure being studied. Previous studies, however, have all involved single-country panels. We tested the feasibility of carrying out a multinational panel to rate the appropriateness and necessity of coronary revascularization, thereby producing recommendations for common European criteria.

METHODS

Using the RAND methodology, a multispecialty (interventional cardiologists, non-interventional cardiologists and cardiovascular surgeons), multinational (The Netherlands, Spain, Sweden, Switzerland and the United Kingdom) panel rated the appropriateness and necessity of indications for percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft surgery (CABG). A synthesis of the evidence and list of indications for PTCA and CABG were sent to 15 panelists, three from each country, who performed their ratings in three rounds.

RESULTS

For PTCA, 24% of the indications were appropriate and necessary, 16% were appropriate, 43% were uncertain and 17% were inappropriate. The corresponding values for CABG were 33% appropriate and necessary, 7% appropriate, 40% uncertain and 20% inappropriate. The proportion of indications rated with disagreement was 4% for PTCA and 7% for CABG.

CONCLUSION

Multinational panels appear to be a feasible method of addressing issues concerning the appropriateness and necessity of medical procedures in western European countries. The criteria produced provide a common tool that can be used to measure the overuse and underuse of medical procedures and to guide decision-making.

Angiographic and clinical outcomes after rescue coronary stenting

The role of coronary stenting in improving outcomes after failed thrombolysis has not been well described. This study represents a registry of rescue coronary interventions performed during a 3 year period in which interventional treatment was changing for this high risk population. We analyzed acute angiographic results and clinical outcomes in 108 consecutive patients treated for thrombolytic failure with either balloon angioplasty (n = 63) or coronary stenting (n = 45). The overall in-hospital mortality rate was 5.5%, and there was no increase in complications in the stent group. Coronary stenting was associated with improved angiographic results including lower residual stenosis in the culprit artery (15 +/- 10% vs. 31 +/- 22%, P < 0.001) without increasing bleeding complications. The rate of in-hospital and long term target vessel revascularization in the stent group was significantly lower than in the unmatched PTCA group. Rescue coronary stenting is safe, improves acute angiographic results compared to PTCA alone and leads to excellent in-hospital and long term outcomes.

Triage of patients for short term observation after elective coronary angioplasty

OBJECTIVE

To evaluate triage of patients for short term observation after elective percutaneous transluminal coronary angioplasty (PTCA), as appropriate selection of patients for short term observation after angioplasty may facilitate early discharge.

METHODS

1015 consecutive patients scheduled for elective PTCA were prospectively included for short term observation. Patients with unstable angina Braunwald class III were excluded. There were no angiographic exclusion criteria. Patients were discharged from the interventional centre when considered stable during 4 hours of observation after PTCA. It was left to the operator's discretion whether to prolong the observation period. Procedural complications were defined as death, coronary bypass surgery, early repeat PTCA, and myocardial infarction.

OUTCOME MEASURES

The need for prolonged observation (> 4 hours) and the occurrence of complications. Predictors for prolonged observation and the occurrence of complications after the 4 hours observation were assessed by univariate and multivariate analysis.

RESULTS

Two patients died, including one of six patients who underwent emergency bypass surgery. In all, 922 patients (90.8%) were triaged to short term observation and had an uncomplicated three day follow up. Observation was prolonged in 87 patients (8.6%), and 40 patients had a complicated course. Independent predictors of procedural complications were acute closure (odds ratio (OR) 9.7; 95% confidence interval 4.4 to 21.4), side branch occlusion (OR 8.9; 3.4 to 23.7), no angiographic success (OR 5.1; 2.4 to 11.0), female sex (OR 3.1, 1.7 to 5.7), any unplanned stent (OR 2.8, 1.4 to 5.9), and ostial lesion (OR 2.2, 1.0 to 4.7).

CONCLUSIONS

A 4 hour observation period is safe after elective coronary angioplasty. As procedural variables are the strongest predictors of postprocedural complications, the immediate procedural results allow effective triage of patients for short term or prolonged observation in order to anticipate complications.

The relative influence of lesion length and other stenosis morphologies on procedural success of coronary intervention

As coronary interventional technology improves, the influence of lesion length (LL) on procedural success and device selection may vary. Thus, the authors prospectively analyzed 957 consecutive coronary interventions (CI) in 1,404 stenoses to ascertain the influence of lesion length on CI outcome. Stenosis morphology was prospectively classified by the AHA/ACC criteria. LL was analyzed both as dichotomous (S: < 10 mm, L: > 10 mm) variables and by the three-tiered AHA/ACC criteria (I: < 10 mm, II: 10-20 mm, III: > 20 mm). There was a significant univariate relationship between CI success and S stenosis (S: 95.8% vs L: 91.8%, p = 0.002 and I: 96.0%, II: 91.7%, III: 89.3%). Numerous interrelationships involving the morphologic characteristics were noted: lesion morphologies associated with S lesions were concentric (p = 0.0001) and had smooth contour (p = 0.0001), ostial location (p = 0.05) and little calcification (p = 0.0007), while irregular contour (p=0.0001), calcification (p=0.0076), eccentric (p=0.0001), thrombus (p = 0.0001), recent (p = 0.0001) or chronic (p = 0.001) total occlusion were associated with L lesions. When these relationships were taken into account by multiple logistic regression analysis, lesion length was not predictive of procedural outcome (p = 0.099). One morphologic type was associated with increased CI success: irregular contour (p = 0.022); recent (p < 0.0001) or chronic (< 0.0001) occlusions were associated with decreased CI success. Another factor considered was device selection: S lesions were associated with greater balloon angioplasty usage (p = 0.002), whereas more coronary stents (p = 0.024) and rotoblator (p = 0.018) devices were used in L lesions. More balloon angioplasty was performed in concentric (p < 0.0001) lesions; interventional devices were employed more often in eccentric (p < 0.0001) and irregular lesions (p < 0.0001). More complications were noted in lesions with thrombus (p = 0.0002), but lesion length was not predictive (p = NS). Lesion length is not a significant predictor of procedural success when adjusted for other lesion morphologies in the modern interventional era. The availability of new devices has improved the results in longer lesions since the AHA/ACC criteria were originally proposed.

Relation between lesion characteristics and risk with percutaneous intervention in the stent and glycoprotein IIb/IIIa era: An analysis of results from 10,907 lesions and proposal for new classification scheme

BACKGROUND

The currently used American College of Cardiology/American Heart Association lesion classification scheme dates from an era when balloon angioplasty was the only percutaneous treatment available and major complications occurred in approximately 7% of patients. Major advances in treatment options would suggest that this scheme may be outmoded, but the schemes that have been suggested to update lesion classification have not been widely accepted.

METHODS AND RESULTS

Four thousand one hundred eighty-one consecutive patients (6,676 lesions) formed a training set and 2,146 patients (4,231 lesions) formed a validation set treated from 1995 to 1997 at a single center used by 3 hospital groups. Twenty-seven pretreatment candidate variables were analyzed with the use of stepwise proportional logistic regression, and 9 (nonchronic total occlusion with TIMI flow 0, degenerated vein graft, vein graft age >10 years, lesion length >/= 10 mm, severe calcium, lesion irregularity, large filling defect, angulated >/= 45 degrees plus calcium, and eccentricity) were independently correlated (P<0.05) with ranked adverse outcome (death, Q-wave or creatine kinase >/= 3x normal myocardial infarction, or emergency coronary artery bypass grafting>>creatine kinase 2 to 3x myocardial infarction>>possibly related to non-Q-wave myocardial infarction>>no complication). A scheme based on these findings and the old American College of Cardiology/American Heart Association scheme were found to have c-statistics in the validation set of 0.672 and 0.620 (P = 0.010 vs old scheme), respectively.

CONCLUSIONS

Appreciation of these contemporary risk factors for complications of coronary intervention may assist in patient selection and in risk adjustment for comparison of outcomes between providers.

Risk predictors in patients scheduled for percutaneous coronary revascularization

Traditionally, procedural risks associated with conventional balloon coronary angioplasty have been largely attributed to unfavorable lesion morphology. However, factors predicting adverse events in the current practice of percutaneous coronary revascularization are unclear. The present study was undertaken to determine factors predicting major adverse events (death or Q-wave myocardial infarction or emergency bypass surgery) in 3,335 consecutive patients undergoing percutaneous coronary revascularization in the current practice of percutaneous coronary revascularization. During the period of observation, the rate of lesions treated successfully increased from 91% to 95% (P < 0.0001), whereas the rate of major adverse events (MACE) decreased from 3.6% to 1.6% (odds ratio [OR], 0.70 per year). Using multiple stepwise logistic regression analysis, cardiogenic shock (OR, 8.59; confidence interval [CI], 4.27-17.27), renal disease (OR, 3.33; CI, 1.95-5.69), evolving myocardial infarction (OR, 2.80; CI, 1.47-5.31), congestive heart failure (OR, 2.18; CI, 1.23-3.86), total number of lesions treated (OR, 1.28; CI, 1.03-1.59), age (OR, 1.03; CI, 1.01-1.06), and history of prior coronary intervention (OR, 0.51; CI 0.26-0.99) were identified as independent predictors of MACE. In addition, vascular disease (OR, 2. 48; CI 1.37-4.50) and unstable angina pectoris (OR, 0.44; CI 0.25-0. 79) were related to adverse events when patients in cardiogenic shock were excluded from the model. With the exception of most unfavorable lesion morphology (AHA/ACC lesion type C; OR, 2.05; CI, 1.19-3.52), anatomic parameters added no further information. In the present era of device technology, success rates of percutaneous coronary revascularization procedures have increased and remain to be determined by lesion morphology. In contrast, the rate of MACE is declining and best predicted by easily identified patient characteristics.

Multivariate prediction of in-hospital mortality after percutaneous coronary interventions in 1994-1996. Northern New England Cardiovascular Disease Study Group

OBJECTIVES

Using recent data, we sought to identify risk factors associated with in-hospital mortality among patients undergoing percutaneous coronary interventions.

BACKGROUND

The ability to accurately predict the risk of an adverse outcome is important in clinical decision making and for risk adjustment when assessing quality of care. Most clinical prediction rules for percutaneous coronary intervention (PCI) were developed using data collected before the broader use of new interventional devices.

METHODS

Data were collected on 15,331 consecutive hospital admissions by six clinical centers. Logistic regression analysis was used to predict the risk of in-hospital mortality.

RESULTS

Variables associated with an increased risk of in-hospital mortality included older age, congestive heart failure, peripheral or cerebrovascular disease, increased creatinine levels, lowered ejection fraction, treatment of cardiogenic shock, treatment of an acute myocardial infarction, urgent priority, emergent priority, preprocedure insertion of an intraaortic balloon pump and PCI of a type C lesion. The receiver operating characteristic area for the predicted probability of death was 0.88, indicating a good ability to discriminate. The rule was well calibrated, predicting accurately at all levels of risk. Bootstrapping demonstrated that the estimate was stable and performed well among different patient subsets.

CONCLUSIONS

In the current era of interventional cardiology, accurate calculation of the risk of in-hospital mortality after a percutaneous coronary intervention is feasible and may be useful for patient counseling and for quality improvement purposes.

Implications of small reference vessel diameter in patients undergoing percutaneous coronary revascularization

OBJECTIVES

The purpose of this study was to determine whether small reference diameter of the culprit coronary artery influences the outcome of an attempted percutaneous revascularization procedure in the current era of interventional cardiology.

BACKGROUND

Although the interventional strategy is largely determined by the size of the culprit coronary artery, earlier quantitative studies have not shown a worse acute outcome for small reference vessel diameter (< or =2.5 mm).

METHODS

A total of 2,306 patients undergoing percutaneous coronary revascularization was divided in groups with reference diameters < or =2.5 mm (n = 813) or >2.5 mm (n = 1,493). Success and in-hospital major adverse cardiac event (death, Q-wave myocardial infarction and emergency coronary artery bypass graft) rates between both groups were compared.

RESULTS

Patients with lesions in small vessels were older and presented more frequently with female gender, diabetes mellitus, heart failure, peripheral vascular, multivessel coronary disease and American Heart Association/American College of Cardiology (AHA/ACC) lesion type C (p < or = 0.01, each). Further, utilization of interventional devices differed markedly. In contrast to stents (18.5% vs. 41.9%) and directional atherectomy (3.7% vs. 13.5%), conventional balloon angioplasty (73% vs. 50%) and rotational atherectomy (16.1% vs. 8.3%) were used more often in smaller vessels (p < or = 0.0001, each). Success rate was lower in the small vessel group (92% vs. 95%; p = 0.006). Major adverse cardiac events occurred more frequently in small than large vessels (univariate 3.4% vs. 2.0%, p = 0.03; multivariate odds ratio 2.1, p = 0.02), particularly when proximal coronary segments were compared.

CONCLUSIONS

Lesions in vessels with small reference diameter represent a distinct group with respect to clinical and morphologic characteristics as well as device utilization. These lesions have lower chances of successful percutaneous intervention and carry relatively higher risks, specifically when located in proximal coronary segments.

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.

Reduction in the need for unplanned stenting with the use of platelet glycoprotein IIb/IIIa blockade in percutaneous coronary intervention

Data from the 5 large randomized, double-blind, placebo-controlled trials that used glycoprotein IIb/IIIa inhibitors during percutaneous transluminal coronary angioplasty were pooled for a total of 10,691 patients. We found that the use of glycoprotein IIb/IIIa inhibitors in percutaneous coronary interventions significantly decreases the need for unplanned stenting for abrupt closure.

A randomized comparison of bivalirudin and heparin in patients undergoing coronary angioplasty for postinfarction angina. Hirulog Angioplasty Study Investigators

The outcome of coronary angioplasty performed for unstable angina is determined, in part, by the acuteness and severity of the clinical presentation. The risk of abrupt vessel closure is increased in patients with postinfarction angina. The Hirulog Angioplasty Study compared the efficacy and safety of bivalirudin with weight-adjusted heparin in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) for unstable or postinfarction angina. We report the results of the intent-to-treat analysis using adjudicated data for the prespecified group of 741 patients who underwent angioplasty within 2 weeks of documented myocardial infarction. Patients received either bivalirudin or heparin immediately before angioplasty. The primary efficacy endpoint was procedural failure defined as abrupt vessel closure, death, myocardial infarction, or revascularization during hospitalization. Bivalirudin significantly (p = 0.004) decreased the incidence of procedural failure compared with heparin (5.1% vs 10.8%, odds ratio 0.45; 95% CI 0.25-0.79). The improved efficacy of bivalirudin was replicated for each individual clinical endpoint. The incidence of major bleeding was significantly (p = 0.001) lower in bivalirudin-treated patients compared with heparin-treated patients (2.4% vs 11.8%, respectively). The benefits observed with bivalirudin are of similar magnitude as those reported for platelet glycoprotein (GP) IIb/IIIa inhibitors, such as abciximab. Bivalirudin may be a more effective foundation anticoagulant than heparin in patients undergoing coronary angioplasty for postinfarction angina.

Value of the American College of Cardiology/American Heart Association stenosis morphology classification for coronary interventions in the late 1990s

The goal of this study was to reassess the accuracy of the American College of Cardiology/American Heart Association (ACC/AHA) stenosis morphology classification for predicting coronary intervention success and complications in the era of new devices. Previous studies performed in the early part of this decade for percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease found that these criteria were predictive of success rates but not complication rates. Data for 957 consecutive coronary interventions in 1,404 lesions from June 1994 to October 1996 were prospectively classified according to ACC/AHA guidelines and entered into a database. Ninety-one and 9/10 of coronary interventions were successful, defined as <50% residual stenosis of each vessel attempted in the absence of major in-hospital complications, including Q-wave myocardial infarction, ventricular arrhythmia, need for emergency coronary artery bypass surgery, or death. Success rates did not differ between A (186 of 193, 96.3%), B1 (211 of 221, 95.5%), and B2 (676 of 711, 95.1%) lesions, but each was more successful than C (246 of 279, 88.2%) lesions (p <0.003, p < 0.004, and p = 0.0001, respectively). The class of lesion (A, B, or C) did not predict device (atherectomy, rotablator, and stent) use but specific morphologic characteristics of lesions within these classes were predictive of which device was used. Multiple regression analysis revealed that total occlusion and vessel tortuosity were predictive of procedure failure. Lesion type (A, B, or C) was not predictive of complications, but bifurcation lesions (p = 0.0045), presence of thrombus (p = 0.0001), inability to protect a major side branch (p = 0.0468), and degenerated vein graft lesions (p = 0.0283) were predictive. Thus, the ACC/AHA grading system is predictive of successful coronary intervention outcome, particularly of C-type characteristics, but not of complications or device success rate and selection. Although lesion type (A, B, or C) was not predictive of complications, specific lesion morphologies were predictive of adverse events and device use.

The clinical impact of platelet glycoprotein IIb/IIIa receptor blockade in cardiovascular medicine

Several of the adverse events that occur in acute coronary syndromes and after percutaneous coronary revascularization procedures are believed to be mediated by platelets. Recently, using molecular biology techniques, the platelet glycoprotein IIb/IIIa receptor was identified as the final common pathway for platelet aggregation. Thus, blocking the action of this receptor would seem to be an attractive proposition for reducing ischemic complications. A monoclonal antibody was the first agent in this new pharmacological family to be designed, but several peptide and peptide-like substances have subsequently been developed. This paper reviews the development of this class of agents and the various preclinical and clinical trials that have been undertaken. Early studies evaluated such agents during percutaneous coronary revascularization procedures. Because of the overwhelming benefits observed in such patients, together with the current limitations of treatments for acute coronary syndromes, the scope of investigations has been extended. Preliminary reports have been encouraging.

Pharmacologic prevention of acute ischemic complications of coronary angioplasty

The risk of acute coronary occlusion following percutaneous transluminal coronary angioplasty (PTCA) has remained high despite the traditional use of heparin and aspirin. Interest has focused on newer strategies for preventing intracoronary thrombus formation, which is an important mechanism of abrupt vessel closure. Pretreatment with thrombolytic agents has failed vigorous testing in double-blind trials. Retrospective and observational studies have indicated that pretreatment with intravenous heparin is of benefit in patients with unstable symptoms, but prolonged infusion after angioplasty increases bleeding complications without improving outcomes. Subcutaneous heparin may be safer, but has not proved more effective. Oral dipyridamole has shown no advantage over aspirin, although there is evidence to suggest a benefit when given intravenously. Direct thrombin inhibitors (such as hirudin and hirulog) are associated with fewer early complications compared with heparin, but have yielded no apparent long-term benefit. The use of the antiplatelet drug ticlopidine is increasing, although long-term data are lacking. A great deal of recent interest has focused on newer antiplatelet agents, particularly the glycoprotein IIB/IIIa receptor inhibitor c7E3 Fab. In a large-scale trial, c7E3 significantly reduced the 30-day rate of mortality and cardiac events, and these benefits were maintained at 6 mo. This drug, unlike other antiplatelet agents, inhibits the final common pathway of platelet aggregation, which influences not only acute closure but has lasting effects for at least 6 mo. This may reflect a reduction in restenosis, although this remains to be proven. This article gives a brief overview of the pharmacologic agents available for the prophylaxis and treatment of acute ischemic complications of PTCA.

Abrupt vessel closure: changing importance, management, and consequences

Percutaneous coronary interventions have been performed for 20 years. Despite the success and progress of these interventions, abrupt vessel closure has been a dramatic adverse event of coronary interventions. Closure has frequently led to the major complications of death, myocardial infarction, and emergency coronary artery bypass. Because of the fear of this adverse event and its subsequent complications, the applicability of coronary interventions is sometimes limited. The pathologic characteristics of abrupt vessel closure have been recognized as predominantly caused by dissection, with vessel recoil and thrombus formation playing important secondary roles. The recognition of the lesions at risk for abrupt vessel closure has led to a strategy of lesion-specific device therapy to reduce complications. Similarly the role of antiplatelet and antithrombotic therapies have reduced complications. The earliest methods of dealing with abrupt closure was emergency coronary artery bypass surgery with significant rates of morbidity and mortality. With the advent of second-generation devices and techniques, particularly stents, the management of abrupt vessel closure has been simplified and alternatives to emergency coronary bypass are more available. This article will review the history and current status of the prevention and management of abrupt vessel closure and demonstrate that anticipation and management of this complication have been facilitated with reduction of subsequent complications and increased applicability of coronary interventions.

Site-specific intracoronary thrombolysis with urokinase-coated hydrogel balloons: acute and follow-up studies in 95 patients

Conventional balloon angioplasty in the presence of intracoronary thrombus is associated with an elevated risk for acute myocardial infarction, emergency bypass surgery, and death. The purpose of this study was to assess the safety and efficacy of a new technique to treat thrombus-containing stenoses consisting of the local delivery of urokinase directly to the site of intraluminal clot with hydrogel-coated balloons. Ninety-five patients with angiographically apparent intracoronary thrombus were treated with urokinase-coated hydrogel balloons either prior to (n = 74) or following (n = 21) conventional balloon angioplasty. Clinical diagnoses for the study group included acute myocardial infarction in 50 patients, postinfarction angina in 23 patients, and unstable angina in 22 patients. All hydrogel balloons were initially coated with urokinase by immersing the inflated balloon in a concentrated Abbokinase solution (50,000 units/ml) for 60 s. All patients were subsequently treated with drug-coated balloons using a balloon:artery ratio of 1:1, a mean of 2.2 +/- 1.2 inflations, and a mean total inflation time of 7.5 +/- 4.9 min. Use of urokinase-coated balloons resulted in angiographic disappearance of intracoronary thrombus in 78 patients, improvement in 14, and no change in the remaining 3 patients. Following hydrogel balloon use for the entire 95 patients, TIMI flow increased from 1.4 +/- 1.2 to 2.9 +/- 0.4, minimal lumen diameter increased from 0.4 +/- 0.4 to 2.0 +/- 0.6 mm, and thrombus score decreased from 2.0 +/- 0.9 to 0.2 +/- 0.6 (all P < 0.01). Procedural and early in-hospital complications were noted in 7 of the 95 patients (7.4%) and included abrupt closure in 3 patients, distal embolization in 1 patient, no reflow in 1 patient, sidebranch occlusion in 1 patient, and late closure in 1 patient. Two of the 3 patients with abrupt closure and the single patient with late closure required intracoronary stenting to maintain vessel patency. Two of these 7 patients sustained small myocardial infarctions, although no patient required emergency bypass surgery or experienced a procedural death. Late clinical follow-up (mean = 8.3 +/- 6.6 months; range = 2 wk to 29 mo) demonstrated adverse recurrent events in 29 of the 95 patients (30.5%), including death (n = 5), myocardial infarction (n = 2), and recurrence of angina (n = 22). The results of this study suggest that intracoronary thrombolysis can be safely and rapidly achieved by using limited quantities of urokinase delivered directly to the site of intraluminal clot with hydrogel balloons. Use of this technique may result in improved acute outcomes in comparison with conventional techniques currently being used to treat thrombus-containing stenoses.

In vivo validation of intravascular ultrasound length measurements using a motorized transducer pullback system

Using sonoreflective endovascular targets of known length (stainless steel tubular slotted stents), we have validated in vivo the accuracy and reproducibility of intravascular ultrasound length measurements using a system incorporating motorized transducer pullback through a stationary imaging sheath. The correlation was r = 0.936, with a measurement error of only +/- 5.2%, minimal intraobserver variability, and variability of sequential measurements of only +/- 4.8%.

Lesion-directed administration of alteplase with intracoronary heparin in patients with unstable angina and coronary thrombus undergoing angioplasty

Percutaneous coronary revascularization in patients with unstable angina and coronary thrombus carries a high complication rate. A new strategy to reduce thrombus burden before revascularization was tested in a multicenter prospective trial. Patients with unstable angina and coronary thrombus (n = 45) received alteplase through an infusion catheter at the proximal aspect of the target lesion and concomitant intracoronary heparin via a standard guiding catheter. Angiography was performed before and alter lesion-directed therapy and post-intervention. Systemic fibrinogen depletion and thrombin activation were not observed, while fibrinolysis was evident for > or = 4 hr after treatment. Target lesion stenosis did not change significantly after lesion-directed therapy, but thrombus score was reduced, particularly among patients who had large thrombi (mean 2.2 vs. 1.6, P = 0.02). Revascularization was successful in 89% of patients. Median final stenosis was 30% and mean final thrombus score was 0.4. Complications included recurrent ischemia (11%), MI (7%), abrupt closure (7%), severe bleeding (4%), and repeat emergency angioplasty (2%). Patients with overt thrombus appeared to derive the most angiographic benefit from lesion-directed alteplase plus intracoronary heparin. Later revascularization was highly successful. This strategy may be a useful adjunct to percutaneous revascularization for patients with unstable angina and frank intracoronary thrombus.

Relation between activated clotting time during angioplasty and abrupt closure

BACKGROUND

The purpose of this study was to determine whether the degree of heparin anticoagulation during coronary angioplasty, as measured by the activated clotting time, is related to the risk of abrupt vessel closure.

METHODS AND RESULTS

Sixty-two cases of in- and out-of-laboratory abrupt closure in patients in whom intraprocedure activated clotting times were measured were identified from a population of 1290 consecutive patients who underwent non-emergency coronary angioplasty. This group was compared with a matched control population of 124 patients who did not experience abrupt closure. Relative to the control population, patients who experienced abrupt closure had significantly lower initial (median, 350 seconds [25th to 75th percentile, 309 to 401 seconds] versus 380 seconds [335 to 423 seconds], P = .004) and minimum (345 seconds [287 to 387 seconds] versus 370 seconds [321 to 417 seconds], P = .014) activated clotting times. Higher activated clotting times were not associated with an increased likelihood of major bleeding complications. Within this population, a strong inverse linear relation existed between the activated clotting time and the probability of abrupt closure.

CONCLUSIONS

This study demonstrates a significant inverse relation between the degree of anticoagulation during angioplasty and the risk of abrupt closure. A minimum target activated clotting time could not be identified; rather, the higher the intensity of anticoagulation, the lower the risk of abrupt closure.

Development and validation of simplified predictive index for major complications in contemporary percutaneous transluminal coronary angioplasty practice. The Registry Committee of the Society for Cardiac Angiography and Interventions

OBJECTIVES

This study was designed to determine the preprocedural risk factors for major complications (emergent coronary bypass surgery, myocardial infarction or death) of coronary angioplasty and to derive and validate a simplified index that predicts patients' a priori risk of complications.

BACKGROUND

Previous studies of risk factors for complications after coronary angioplasty may not be generalizable to current, broad-based angioplasty practice. Furthermore, to our knowledge a clinically useful predictive index has not been derived and independently validated.

METHODS

From data collected prospectively for the Registry of the Society for Cardiac Angiography and Interventions for 1992, multivariable logistic regression was used to determine which variables were independently associated with complications in 10,622 first angioplasty procedures. Stepwise regression and receiver operating characteristic curves then were used in this registry to develop a predictive index for complications that was validated using 5,250 first angioplasty procedures in the 1993 registry.

RESULTS

Predictors of major complications were multivessel disease, unstable angina, recent myocardial infarction, type C lesion or left main angioplasty, shock, age, geographic region and absence of previous coronary bypass surgery. The derived predictive index consisted of the first six of these variables plus aortic valve disease and classified patients into four risk groups: low (1.3% complications), moderate (2.8%), high (12.7%) and very high (29.7%) risk. This index demonstrated consistent reliability and discriminatory ability when applied to the 1993 data.

CONCLUSIONS

Predictors of major complications identified in selected populations also apply currently in broad-based practice. From these variables, a predictive index can stratify patients into risk groups before angioplasty, thus aiding in risk assessment, resource allocation and risk adjustment.

Length of hospital stay and complications after percutaneous transluminal coronary angioplasty. Clinical and procedural predictors. Heparin Registry Investigators

BACKGROUND

Although several studies have established that the complications of percutaneous transluminal coronary angioplasty (PTCA) are related to clinical and angiographic variables such as advanced age and lesion complexity, it is uncertain whether the use of hospital resources after PTCA also depends on the same baseline variables. The purpose of this study was to identify the factors responsible for prolonged hospital stay after PTCA.

METHODS AND RESULTS

The study cohort included 591 consecutive patients undergoing conventional balloon angioplasty at nine medical centers in North America. Major or minor complications occurred in 91 patients (15.4%) and were observed to be related to several baseline characteristics, including unstable angina, multivessel coronary artery disease, patient age, and lesion complexity. Compared with a median length of hospital stay of 2.0 days after PTCA (25th, 75th percentiles: 2.0, 4.0) for the entire cohort of patients, the length of stay was increased in patients with unstable angina (3.0 days [2.0, 5.0]; P = .002), multivessel coronary artery disease (3.0 [2.0, 5.5]; P = .001), age > 65 years (3.0 [2.0, 5.5]; P = .02), complex lesions (3.0 [2.0, 6.0]; P = .001), and filling defects (6.0 [2.0, 11.0]; P < .001). The length of stay was more strikingly increased, however, in patients who experienced major or minor PTCA complications, such as emergency bypass surgery (9.0 days [8.0, 18.0]; P < .001), Q-wave or non-Q-wave myocardial infarction (8.0 [6.0, 15.5]; P < .001), transfusion unrelated to bypass surgery (8.0 [4.0, 12.0]; P < .001), or abrupt vessel closure (6.0 [3.0, 10.5]; P < .001). On stepwise multiple linear regression, PTCA complications appeared to be the strongest predictors of length of hospital stay (all P < .001) and overwhelmed the weaker relation between length of stay and several individual baseline variables. Inclusion of a composite clinical risk score (reflecting the presence of unstable angina, multivessel disease, advanced age, complex lesions, or filling defects) in the regression model confirmed that patients with several high-risk baseline variables had a significant increase in length of stay after PTCA (P = .003), but PTCA complications remained the strongest predictors of length of stay.

CONCLUSIONS

Although PTCA complications were correlated with baseline variables such as unstable angina, multivessel disease, advanced age, complex lesions, and filling defects, excess length of stay after PTCA was most strongly influenced by the development of minor and major PTCA complications. Because patients with several baseline risk factors experienced significantly prolonged hospitalizations, improved selection of patients may contribute to reductions in length of stay after PTCA. A greater reduction in resource use after PTCA, however, would be expected from developing new treatments to decrease PTCA complications rather than limiting the access of patients with unstable angina, advanced age, or complex lesions to PTCA.