Percutaneous transluminal coronary angioplasty for unstable angina

Intracoronary dipyridamole reduces the incidence of abrupt vessel closure following PTCA: a prospective randomised trial

OBJECTIVES

To investigate the effect of intracoronary dipyridamole on the incidence of abrupt vessel closure, myocardial infarction, necessity for bypass grafting, and death following percutaneous transluminal coronary angioplasty (PTCA).

PATIENTS

Patients were randomly allocated to receive either conventional pretreatment (heparin 15 000 IU and aspirin 500 mg intravenously) or additional intracoronary dipyridamole (0.5 mg/kg bodyweight). Dipyridamole was administered in 550 PTCA procedures (455 interventions in men, mean (SD) age 59.2 (8.4) years; 74 acute coronary syndromes), while conventional pretreatment was administered in 544 interventions (444 interventions in men 58.3 (7.9) years old; 81 acute coronary syndromes). In 53 interventions bail out stenting was performed for threatened abrupt vessel closure.

RESULTS

Intracoronary dipyridamole significantly reduced the incidence of abrupt vessel closure (odds ratio 0.42. 95% confidence interval (CI) 0.22 to 0.79). While abrupt vessel closure occurred in 6.1% of interventions following conventional pretreatment, dipyridamole reduced the incidence to 2.5%. Restricting the analysis to balloon angioplasty, this reduction was observed in patients with stable angina (odds ratio 0.49, 95% CI 0.23 to 0.96) as well as in those with acute coronary syndromes (odds ratio 0.29, 95% CI 0.09 to 0.87). Reduction of secondary end points in the dipyridamole treated patients failed to reach significance in the PTCA group.

CONCLUSIONS

Intracoronary dipyridamole before PTCA reduces the incidence of abrupt vessel closure following PTCA for stable angina and acute coronary syndromes.

Management of high-risk subsets in unstable angina

This article focuses on the optimal treatment of postinfarction, refractory, or recurrent angina based on the results of recent clinical trials. Many of our recommendations hold true for the general management of unstable angina, but special considerations for the high-risk subsets are emphasized. Specifically, we discuss acute medical management and suggest that an early aggressive strategy that leads to early coronary angiography with the goal of revascularization when feasible best serves this subset. A special emphasis on the emerging role of glycoprotein IIb-IIIa antagonists is made because the important role of platelets in coronary thrombosis has dominated recent views on the pathophysiology of unstable angina.

Abciximab in primary coronary angioplasty for acute myocardial infarction improves short- and medium-term outcomes

OBJECTIVES

The purpose of this study was to compare the outcome of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction (MI) when performed with or without the platelet glycoprotein IIb/IIIa antibody, abciximab.

BACKGROUND

Abciximab improves the outcome of angioplasty but the effect of abciximab in primary angioplasty has not been investigated.

METHODS

Data were collected from a computerized database. Follow-up was by telephone or review of outpatient or hospital readmission records.

RESULTS

A total of 182 consecutive patients were included; 103 received abciximab and 79 did not. The procedural success rate was 95% in the two groups. At 30-day follow-up, the composite event rate of unstable angina, reinfarction, target vessel revascularization and death from all causes was 13.5% in the group of patients who did not receive abciximab, 4% (p < 0.05) in the abciximab group and 2.4% (p < 0.05) in the subgroup of patients (n = 87) who completed the 12-h abciximab infusion. At the end of follow-up (mean 7+/-4 months), the composite event rate was 32.4%, 17% (p < 0.05) and 13.1% (p < 0.01) in these three categories respectively. Abciximab bolus followed by a 12-h infusion was an independent predictor of event-free survival, in a Cox proportional hazards model (relative risk 0.49; 95% confidence interval 0.24 to 0.99; p < 0.05).

CONCLUSIONS

Abciximab given at the time of primary angioplasty may improve the short- and medium-term outcome of patients with acute MI, especially when a 12-h infusion is completed.

Evidence for prevention of death and myocardial infarction with platelet membrane glycoprotein IIb/IIIa receptor blockade by abciximab (c7E3 Fab) among patients with unstable angina undergoing percutaneous coronary revascularization. EPIC Investigators. Evaluation of 7E3 in Preventing Ischemic Complications

OBJECTIVES

We sought to evaluate whether patients with unstable angina undergoing coronary intervention derive particular clinical benefit from potent platelet inhibition.

BACKGROUND

Plaque rupture and platelet aggregation are pathogenetic processes common to unstable angina and ischemic complications of percutaneous coronary intervention.

METHODS

Of the 2,099 patients undergoing a coronary intervention in the Evaluation of 7E3 in Preventing Ischemic Complications (EPIC) trial, 489 were enrolled with the diagnosis of unstable angina and randomized to receive placebo, an abciximab (c7E3) bolus immediately before the intervention or an abciximab bolus followed by a 12-h infusion. The primary end point was a composite of death, myocardial infarction (MI) or urgent repeat revascularization within 30 days of randomization. The occurrence of death, MI or any revascularization within 6 months was also assessed.

RESULTS

Compared with placebo, the bolus and infusion of abciximab resulted in a 62% reduction in the rate of the primary end point (12.8% vs. 4.8%, p = 0.012) among patients with unstable angina, due primarily to a reduction in the incidences of death (3.2% vs. 1.2%, p = 0.164) and MI (9% vs. 1.8%, p = 0.004). By 6 months, cumulative death and MI were further reduced by abciximab (6.6% vs. 1.8%, p = 0.018 and 11.1% vs. 2.4%, p = 0.002, respectively). The magnitude of the risk reduction with abciximab was greater among the patients with unstable angina than among other patients in the EPIC trial without unstable angina for the end points of death (interaction: p = 0.008 at 30 days, p = 0.002 at 6 months) and MI (interaction: p = 0.004 at 30 days, p = 0.003 at 6 months).

CONCLUSIONS

The syndrome of unstable angina identifies patients who will experience particularly marked reductions in the risk of death and MI with abciximab during coronary intervention.

Comparison of immediate and long-term outcome of coronary angioplasty performed for unstable angina and rest pain in men and women

OBJECTIVE

To determine whether a sex-related difference in outcome is present among patients who undergo percutaneous transluminal coronary angioplasty (PTCA) for unstable angina.

DESIGN

We retrospectively analyzed the results after PTCA was performed between January 1981 and June 1993 in a series of 2,073 men and 941 women with unstable angina and rest pain.

RESULTS

The success rates of PTCA were similar for women and men (87.9% and 87.2%, respectively), as were the in-hospital mortality rates (4.1% and 3.2%, respectively) and the need for emergency coronary artery bypass operation (3.1% and 3.5%, respectively). Fewer women than men had Q-wave myocardial infarction (0.5% versus 1.6%; P = 0.02). During the follow-up period (mean, 4 years), no significant differences were noted between women and men in overall survival (81% and 85% at 6 years, respectively) or survival free of Q-wave myocardial infarction (81% and 83% at 6 years, respectively) with use of the Kaplan-Meier method. Women were less likely than men to have had coronary artery bypass grafting (19% versus 22% at 6 years; P = 0.02), and the occurrence of severe angina was higher in women than in men (52% versus 44% at 6 years; P = 0.001). A subgroup analysis of patients who had myocardial infarction within 7 days preceding PTCA showed a similar pattern of results.

CONCLUSION

After PTCA performed for unstable angina and rest pain, survival rates were excellent in both women and men, and no difference was observed in subsequent myocardial infarction rates. During follow-up, however, women were more likely to have severe angina and were less likely to have had coronary artery bypass grafting. Concerns about possible sex-related complications should not dissuade physicians from performing PTCA when clinically indicated for unstable angina and rest pain.

Angioscopic predictors of early adverse outcome after coronary angioplasty in patients with unstable angina and non-Q-wave myocardial infarction

BACKGROUND

Clinical and angiographic criteria have a limited ability to predict adverse outcome in patients with unstable angina who are undergoing percutaneous transluminal coronary angioplasty (PTCA). We investigated whether the use of angioscopy can improve prediction of early adverse outcome after PTCA.

METHODS AND RESULTS

Angioscopic characterization of the culprit lesion was performed before PTCA in 32 patients with unstable angina and 10 with non-Q-wave infarction. Seven patients (17%) had an adverse outcome (myocardial infarction, repeat PTCA, or need for coronary artery bypass graft surgery) within 24 hours after PTCA. Six of 18 patients with a yellow culprit lesion had an adverse outcome compared with 1 of 24 in whom the culprit lesion was white (P = .03). Six of 20 patients with plaque disruption suffered an adverse outcome compared with 1 of 22 with nondisrupted plaques (P = .04). Six of 17 patients with intraluminal thrombus had an adverse outcome, whereas only 1 of 25 patients without thrombus suffered an adverse outcome (P = .01). Yellow color, disruption, and thrombus at the culprit lesion site were associated with an eightfold increase in risk of adverse outcome after PTCA. The prediction of PTCA outcome based on characteristics of the plaque that were identifiable by angioscopy was superior to that estimated by the use of angiographic variables.

CONCLUSIONS

In patients with unstable angina and non-Q-wave infarction, angioscopic features of disruption, yellow color, or thrombus at the culprit lesion site can identify patients at high risk of early adverse outcome after PTCA. Angioscopy was superior to angiography for prediction of PTCA outcome.

Importance of delaying balloon angioplasty in patients with unstable angina pectoris

Angioplasty in patients with unstable coronary artery disease is associated with higher complication rates compared with patients with stable disease. In this report we describe our results from a group of patients with unstable disease (unstable angina pectoris and postmyocardial infarction) where a strategy of delaying angioplasty for > 5 days after admission was undertaken. Included are 2069 consecutive patients: 1197 treated for stable angina pectoris and 872 treated during admission for unstable angina or myocardial infarction. There was no difference between the two groups in angioplasty success (92.1% stable, 92.3% unstable), failure to dilate without complication (6.4% stable, 6.1% unstable), or in the rate of major complications: death (0.5% stable, 1.1% unstable), Q-wave myocardial infarction (0.9% stable, 1.1% unstable), and emergency coronary artery bypass (0.6% stable, 0.3% unstable). The duration of hospitalization following angioplasty was longer in the unstable group (5.6 +/- 8.1 days vs. 4.2 +/- 4.1 days; p < 0.001) because of longer duration of heparin infusion. There was no difference between groups in minor complications such as groin hematoma and pseudoaneurysm, renal failure, or infections. It was concluded that delaying angioplasty in unstable patients for > 5 days after admission is a safe and effective therapeutic strategy for this group of patients. The need for prolonged heparin infusion after angioplasty is increased in unstable patients and thus the duration of hospitalization after the procedure is longer.

Cardiologist versus internist management of patients with unstable angina: treatment patterns and outcomes

OBJECTIVES

This study sought to assess the impact of generalist versus specialist direction on the pattern of care and outcome in patients admitted to the hospital for unstable angina.

BACKGROUND

Physicians trained as internists or as cardiologists may have different approaches to treating patients with unstable angina.

METHODS

We reviewed a prospectively collected cohort of patients discharged with a diagnosis-related group (DRG) diagnosis of unstable angina from William Beaumont Hospital, a large community-based hospital in southeast Michigan. Of 890 consecutive patients, 225 were treated by internists and 665 by cardiologists. We compared these two groups with respect to patterns of use of established pharmacotherapies for unstable angina, diagnostic testing and clinical outcome.

RESULTS

Patients treated by internists less often had a previous cardiac history (53% vs. 80%, p < or = 0.0001). Internists were less likely to use aspirin (68% vs. 78%, p = 0.032), heparin (67% vs. 84%, p < or = 0.001) or beta-adrenergic blocking agents (18% vs. 30%, p < or = 0.004) in their initial management. Exercise tests were performed more frequently by internist-treated patients (37% vs. 22%, p < or = 0.001), but catheterization (27% vs. 61%, p < or = 0.0001) and angioplasty (7% vs. 40%, p < or = 0.0001) were utilized less frequently. The incidence of myocardial infarction was similar (11% vs. 9%) in the two groups, but the mortality rate tended to be higher (4.0% vs. 1.8%, p = 0.06) in the internist group.

CONCLUSIONS

Patients with unstable angina treated by internists were less likely to receive effective medical therapy or revascularization procedures and experienced a trend to poorer outcome. This study does not support a positive gatekeeper role for generalists in the treatment of unstable angina.

Intracoronary thrombus: still a risk factor for PTCA failure?

Pre-existing intracoronary thrombus has been associated with an increased risk of percutaneous transluminal coronary angioplasty (PTCA) failure. Whether intracoronary thrombus is an independent risk factor for failure is uncertain, as conflicting data exist in the literature. Additionally, given advances in patient selection and angioplasty balloon design, it is uncertain whether the current risk posed by intracoronary thrombus is as substantial as that in the early angioplasty experience. The primary objective of this study was to first assess whether pre-existing coronary thrombus was an independent predictor of angioplasty failure and if so, whether the risk due to thrombus had changed from the early angioplasty experience to the present time. Our prospectively collected angioplasty data base was used to identify individuals undergoing single-vessel angioplasty of a thrombus-containing segment from January 1, 1984 through December 1, 1991. Univariate and multivariate stepwise logistic regression techniques were utilized to analyze clinical, angiographic, and procedural characteristics associated with angioplasty failure. The study period was divided into three separate time periods and these used as variables in our multivariate analysis. In the study population that consisted of 2,699 patients with single-vessel angioplasty, univariate analysis demonstrated that among many factors, thrombus was importantly associated with angioplasty failure (P < 0.0001). A multivariate logistic model of angioplasty failure was developed and thrombus achieved independent predictive significance in this model.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of percutaneous transluminal coronary angioplasty in subsets of unstable angina pectoris

OBJECTIVES

The purpose of this study was to characterize the outcome of coronary angioplasty according to the various presentations of unstable angina pectoris.

BACKGROUND

Although unstable angina is a mosaic of clinical manifestations, a comprehensive analysis of short- and long-term outcome of coronary angioplasty in subsets of unstable angina is not available.

METHODS

Data from 15 clinical centers for the 857 patients with unstable angina in the 1985-1986 National Heart, Lung, and Blood Institute percutaneous transluminal coronary angioplasty registry were analyzed. Five-year follow-up was available in > 96.5%. Patients were first classified as those with (679 [79%]) or without (178 [21%]) rest angina. Patients were also allocated to five mutually exclusive categories of decreasing unstable angina severity: postinfarction angina, acute coronary insufficiency, plain rest angina, accelerating angina and new onset angina.

RESULTS

The group with rest angina had more older patients (p < 0.01) and women (p < 0.001), and a greater proportion had a previous myocardial infarction (p < 0.001) and a left ventricular ejection fraction < or = 50% (p < 0.01) than did the group without rest angina. Angiographic characteristics were nearly the same, whereas procedural characteristics and outcome were the same for both categories. At 5-year follow-up, there was a higher crude mortality rate in patients with than without rest angina (p < 0.05). Resolution into five subsets yielded additional information. Women were more represented only in the acute coronary insufficiency and plain rest angina subsets (p < 0.001). Patients with angina after myocardial infarction had the second shortest history of angina (p < 0.001), the highest percent of smokers (p < 0.01) and, with those with acute coronary insufficiency, the highest incidence of congestive heart failure (p < 0.05) and an ejection fraction < or = 50% (p < 0.001). They had the highest percent of totally occluded arteries, coronary thrombus and collateral blood flow received but also the lowest rate of severe stenoses (p < 0.001 for all). Patients with new onset angina had the highest prevalence of single-vessel disease (p < 0.05), critical and complex stenoses (p < 0.001) and no coronary angioplasty-related deaths. The crude 5-year mortality rate was higher for both postinfarction and acute insufficiency groups (p < 0.05) than for the other subsets. After adjustments for risk factors, no significant differences in adverse event rates remained among the different unstable angina subgroups.

CONCLUSIONS

Analysis of the diverse clinical presentations of unstable angina supports underlying pathogenetic differences. Coronary angioplasty is safe and effective in all subsets of unstable angina. Long-term survival is good in general but is related to the baseline status of left ventricular function.

Discordance in the predictors of mortality vs. those of ischemic complications following transcatheter coronary intervention

Outcomes of percutaneous transluminal coronary angioplasty (PTCA) depend upon the skill of the angioplasty team and on the characteristics of the patient population. Comparisons of outcomes from different laboratories must take into account the latter. A discordance may exist between the baseline predictors of death in hospital following PTCA and those for periprocedural ischemia. Baseline clinical and procedural characteristics of 3,725 patients who underwent PTCA during 1991 and 1992 were compared with complications by multivariate analysis. The age of the patient and the occurrence of an MI within the previous 30 days were the most powerful independent predictors of death. Ischemic complications were not independently associated with these factors. Emergency CABG was associated independently with target lesion complexity and abrupt reclosure, with unstable angina or attempted saphenous vein graft dilatation. Thus, mortality may more directly reflect baseline clinical characteristics than the skill of operators in avoiding ischemic complications.

Directional coronary atherectomy in unstable angina

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect on early acute occlusion rate of adjunctive antithrombotic treatment with intravenously administered dipyridamole during percutaneous transluminal coronary angioplasty

This study compared the acute occlusion and complication rates within 24 hours of coronary angioplasty in three groups of patients. In group 1, 178 procedures were performed by one operator who administered 30 mg of dipyridamole intravenously over 1 hour, starting immediately before the procedure; in group 2, 200 procedures were performed by the same operator before he administered dipyridamole; and in group 3, 599 procedures were performed during the same time period in the same catheterization laboratory by two other operators who did not administer dipyridamole. All patients received an intravenous bolus of heparin and aspirin. Baseline variables were similar in the three groups. The acute closure rate was 2.8% in group 1, 7.5% in group 2, and 5.2% in group 3 (p < 0.05 between groups 1 and 2); acute thrombosis was observed in 0.6%, 3.5%, and 3% of patients, respectively, in the three groups (p < 0.05 between group 1 and both groups 2 and 3), and acute dissection was noted in 2.2%, 4%, and 2% of patients, respectively (p = not significant). The cumulative rate of acute complications (death, acute myocardial infarction, or emergency coronary bypass surgery) was lower in group 1 (1.7%) than in group 2 (5.5%, p < 0.05) and group 3 (3.5%, p = not significant). Therefore in this retrospective study, adjunctive antithrombotic treatment with intravenously administered dipyridamole resulted in lower acute thrombosis and complication rates during the 24-hour period after the procedure than when heparin and aspirin therapy were used alone.

Relation between clinical presentation and angiographic findings in unstable angina pectoris, and comparison with that in stable angina

The diagnosis of unstable angina encompasses a broad spectrum of patients with myocardial ischemia, varying widely in cause, prognosis and responsiveness to therapy. A new clinical classification of unstable angina is based on the following 2 components: severity, and the clinical setting in which unstable angina develops. The hypothesis that this clinical classification correlates with the underlying coronary artery anatomy was tested. In 238 consecutive patients, an unstable angina score ranging from 2 to 6 was determined by adding the scores for severity (1 = unstable angina without pain at rest; 2 = pain at rest > 48 hours before angiography; and 3 = pain at rest < or = 48 hours before angiographic evaluation) and the clinical setting of unstable angina (1 = unstable angina secondary to a noncardiac condition; 2 = primary unstable angina; and 3 = early postinfarction unstable angina). Fifty concurrently studied consecutive patients with stable angina were assigned a score of 0. Patients with unstable angina averaged 63 +/- 11 years of age, and 165 were men (69%). Pain at rest occurred in 202 of 238 patients (85%), and angiography was performed < or = 48 hours in 139 of these patients (69%). Among patients with unstable angina, 5 (2%) had secondary unstable angina, 143 (60%) had primary unstable angina, and 90 (38%) had postinfarction unstable angina. Multivariable regression analysis identified the unstable angina score as the most important predictor of intracoronary thrombus (p = 0.011) and lesion complexity (p = 0.004) in the ischemia-related artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of results of percutaneous transluminal coronary angioplasty with and without selective requirement of surgical standby

To determine the outcome of percutaneous transluminal coronary angioplasty (PTCA) with the use of 2 different strategies of surgical coverage, the results of 1,283 consecutive PTCAs were analyzed. In 269 procedures (21%) (patients considered at high risk should acute vessel closure occur--standby group) the operating room and the surgical team were ready for an immediate intervention. In the remaining 1,014 procedures (79%) (backup group), although the surgical team was "in house," they were not necessarily ready for an immediate intervention. Mean age of the population was 58 +/- 10 years and 84% of patients were men. Coronary risk factors, medical treatment, clinical indication for PTCA, previous coronary surgery and left ventricular ejection fraction were similar in both groups. Dilatation was more frequently multiple (23 vs 16%, p less than 0.05), or performed in the left anterior descending coronary artery (71 vs 46%, p less than 0.001), in bypass grafts (4 vs 2%, p less than 0.02), in proximal coronary segments (72 vs 57%, p less than 0.001) or in lesions at bifurcation (35 vs 28%, p less than 0.02) in the standby than in the backup group, respectively. PTCAs were less frequently performed during the same diagnostic procedure (15 vs 34%, p less than 0.001) in the standby group. Angiographic success was obtained in 91 and 92% of the attempted lesions and PTCA success in 89 and 88% of the procedures in the standby and backup groups, respectively. The incidence of death (1 vs 0.7%), acute myocardial infarction (2.9 vs 2.7%) and emergency surgery (0.7 vs 0.1%) was also similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)