Risk stratification for long-term outcome after elective coronary angioplasty: a multivariate analysis of 5,000 patients.

OBJECTIVES: We attempted to develop a statistical model to facilitate risk stratification for long-term outcome after elective coronary angioplasty. BACKGROUND: Our understanding of factors related to long-term outcome after coronary angioplasty is limited. Adequate assessment of risk indexes could potentially lead to more appropriate use of percutaneous revascularization. METHODS: We studied 5,000 consecutive patients and assessed 19 clinical and anatomic variables as predictors of long-term event-free survival. Events were defined as death of any cause, myocardial infarction, bypass surgery or repeat percutaneous transluminal coronary angioplasty. Cox proportional hazards models were used to develop an equation for predicting event-free survival in a subset of 4,000 patients. The equation was validated with the remaining 1,000 patients. Variables that were significantly associated with an adverse outcome in the multivariate model included age > 60 years, extent of disease, Canadian Cardiovascular Society functional class, previous coronary angioplasty, male gender, history of diabetes mellitus, history of hypertension and history of congestive heart failure. RESULTS: The statistical model was used to develop a simplified scoring system, and the patients were assigned to three risk subgroups. Event-free survival curves for the three groups were significantly different (p = 0.0001). High risk patients had worse outcomes for each of the end points compared with low and moderate risk patients (p < 0.02). CONCLUSIONS: We demonstrated that clinical and anatomic variables can be used to risk-stratify long-term outcome after angioplasty, that a simplified scoring system can be used for risk stratification and that high risk patients have a low event-free survival.

Role of prophylactic anticoagulation for direct current cardioversion in patients with atrial fibrillation or atrial flutter.

The need for prophylactic anticoagulation to prevent embolism before direct current cardioversion is performed for atrial fibrillation or atrial flutter is controversial. To examine this issue further, a retrospective review was undertaken to assess the incidence of embolic complications after cardioversion. The review involved 454 elective direct current cardioversions performed for atrial fibrillation or atrial flutter over a 7 year period. The incidence rate of embolic complications was 1.32% (six patients); the complications ranged from minor visual disturbances to a fatal cerebrovascular event. All six patients had atrial fibrillation, and none had been on anticoagulant therapy (p = 0.026). The duration of atrial fibrillation was less than 1 week in five of the six patients who had embolic complications. Baseline characteristics of patients with a postcardioversion embolic event are compared with those of patients who did not have an embolic event. There was no difference in the prevalence of hypertension, diabetes mellitus or prior stroke between the two groups, and there was no difference in the number of patients who were postoperative or had poor left ventricular function. Left atrial size was similar between the two groups. No patient in the embolic group had valvular disease. No patient with atrial flutter had an embolic event regardless of anticoagulant status; therefore, anticoagulation is not recommended for patients with atrial flutter undergoing cardioversion. Prophylactic anticoagulation is pivotal in patients undergoing elective direct current cardioversion for atrial fibrillation, even those with atrial fibrillation of less than 1 week's duration.

Gender differences for coronary angioplasty.

To determine if differences in early and late outcome after angioplasty were related to gender or body surface area, 5,000 consecutive patients (1,274 women and 3,726 men) were studied. Baseline variables, procedural outcome, and long-term and event-free survival were assessed. Baseline variables included age, history of hypertension, diabetes mellitus, heart failure, myocardial infarction, prior angioplasty or bypass surgery, familial coronary disease, Canadian heart classification, extent of angioplasty, left ventricular function, and body surface area. Overall and event-free survival (freedom from infarction, repeat angioplasty, bypass surgery and death) were assessed at follow-up. The results showed that, compared with men, women were older (p < 0.0001), had a higher prevalence of diabetes (p < 0.0001), familial coronary disease (p = 0.002), hypertension (p < 0.0001), prior infarction (p = 0.004), and more involvement of the anterior descending artery (p = 0.017). Whereas men had similar extents of angioplasty and worse left ventricular function (p = 0.012), women more often had unstable angina (p < 0.0001). The success rates were similar, yet women had a higher procedural mortality (1.1% women, 0.3% men, p = 0.001). When corrected for body surface area, however, women were at no greater risk than men. Follow-up was complete for 97.4% of patients (mean 4 +/- 2 years). Event-free survival was significantly better in women, even after correcting for body surface area. Men were at higher risk for late death and repeat angioplasty on follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Early and late results of coronary angioplasty and bypass in octogenarians.

Early and late results were evaluated for octogenarians undergoing first time revascularization with percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). The study group consisted of 142 patients with CABG and 53 with PTCA. The groups with PTCA and CABG differed with respect to number of patients with angina class III to IV (92 and 67%, respectively; p less than 0.001), number with 3-vessel disease (34 and 77%, respectively; p less than 0.001), presence of left main trunk disease (2 and 24%, respectively; p less than 0.001) and number with normal or mildly impaired left ventricular function (82 and 65%, respectively; p less than 0.034). The groups with PTCA and CABG had similar procedural complications, including myocardial infarction (6 and 4%, respectively) and stroke (0 and 4%, respectively). Hospital mortality was low (6% with CABG and 2% with PTCA). Three year survival, excluding hospital mortality, was 87% in patients with CABG and 81% in those with PTCA (p = 0.493). Octogenarians underwent revascularization procedures with relatively low morbidity and mortality. In regard to the excellent long-term survival, "very" elderly patients with severe coronary artery disease should be considered for revascularization despite advanced age.

Ultrasound imaging of the radial artery following its use for cardiac catheterization.

Our experience suggests transradial arterial access with 5Fr catheters can be used for cardiac angiography with a low incidence of clinical complications, and supports the findings of previous investigators. Subclinical complications at the catheterization site were infrequent in this study (1 patient with asymptomatic radial artery occlusion). The presence of a palpable radial pulse may not be a reliable estimate of artery patency as evidenced by our patient with a palpable pulse due to retrograde flow. The theoretical advantage of the procedure is derived from the dual vascular supply to the hand. Radial artery occlusion, while uncommon, results in no ischemic sequelae in the setting of a patent ulnar artery.

Visualization of acute pulmonary emboli by transesophageal echocardiography.

This report describes a patient who became hypoxic and hypotensive while awaiting cardiac surgery. An urgent transesophageal echocardiogram in the operating room showed a mass at the junction of the main and right pulmonary arteries consistent with thrombus. The thrombus was removed surgically, and the patient then had a successful aortic valve replacement. Transesophageal echocardiography is therefore useful in the evaluation of the critically ill patient.

Role of intimal hyperplasia and arterial remodeling after balloon angioplasty: an experimental study in the atherosclerotic rabbit model.

The arterial response to injury appears to be an important factor in the development or restenosis. Traditionally, intimal hyperplasia has been thought to be the primary mechanism responsible for restenosis. However, recent studies have found that arterial remodeling is a major determinant of lumen loss after balloon angioplasty. In this study, we evaluated the actual separate contributions of intimal hyperplasia and arterial remodeling to the restenotic process after balloon angioplasty in the atherosclerotic rabbit model. One month after induction of focal atherosclerotic lesions, femoral arteries were randomized to receive treatment with either two or six balloon inflations. One group of rabbits was euthanized immediately after angioplasty to evaluate the initial degree of injury with each dilation strategy ("acute group"), and the rest were euthanized 28 days after angioplasty ("chronic group"). Arteries that had been treated with six inflations had a higher injury score than those treated with two (4.0+/-3.0 versus 1.9+/-1.5, P<.05). In the chronic group, there was a significant increase in intimal area in the six inflation-treated arteries compared with the two-inflation group (0.617+/-0.06 versus 0.432+/-0.05 mm2, P<.004). However, there was no significant difference in lumen cross-sectional area between groups. By multivariate analysis, the most important independent predictor of lumen area was the external elastic lamina (EEL) area, although the degree of intimal thickening was also a significant independent predictor. There was a strong, positive correlation between intimal area and EEL area: the larger the intimal area, the larger the EEL area (r=.703, P<.0001). The intimal area was similar in both restenotic and nonrestenotic lesions. In contrast, EEL area was significantly larger (due to remodeling) in nonrestenotic lesions. This study confirms previous findings that the degree of injury determines the degree of neointimal proliferation and supports recent findings that chronic arterial remodeling plays a major role in the final lumen area. Understanding and controlling the remodeling process rather than concentrating solely on intimal hyperplasia may yield better results after balloon angioplasty in the future.

Retrospective analysis of patients undergoing one- or two-stage strategies for myocardial revascularization and implantable cardioverter defibrillator implantation.

Internal defibrillation leads were placed at time of coronary revascularization in 79 patients. In 34, an implantable cardioverter defibrillator (ICD) was placed simultaneously (group I). A two-stage strategy (selective implantation of the ICD in patients with postoperative spontaneous or inducible ventricular tachycardia [VT]) was followed in 45 patients (group II). Group I patients had failed more antiarrhythmic drug trials (2.9 +/- 1.6 vs 1.5 +/- 1.6; P = 0.02), including amiodarone (62% vs 20%; P less than 0.001). There were four operative deaths in each group. Postoperatively, VT was present in 27 group II patients (60%), 25 of whom received an ICD (two refused device implantation). Patients with postoperative VT had a lower left ventricular ejection fraction than those without VT (33 +/- 9 vs 47 +/- 16; P = 0.01). Actuarial survival at 1, 2, and 3 years was 88 +/- 6, 88 +/- 7, and 88 +/- 10 in group I; and 83 +/- 6, 76 +/- 7, and 76 +/- 11 in group II (NS). No patient without an ICD (based on the postoperative electrophysiological study [EPS]) died suddenly. Five patients (6%) had ICD system infection. Sudden death was largely prevented by either strategy, but relatively high rates of operative mortality and ICD system infection were observed. Prospective studies should identify patients more likely to benefit from one or another strategy.

Multicenter, randomized, double-blind, placebo-controlled trial of the platelet integrin glycoprotein IIb/IIIa blocker Integrelin in elective coronary intervention. IMPACT Investigators.

BACKGROUND: Platelet aggregation and thrombosis have been implicated in the pathogenesis of coronary angioplasty complications. Integrelin, a synthetic cyclic heptapeptide with high affinity and marked specificity for platelet integrin glycoprotein IIb/IIIa, effectively blocks ADP-induced platelet aggregation. METHODS AND RESULTS: In 150 patients undergoing elective percutaneous coronary intervention, random assignment was made to one of three treatment regimens: placebo; a 90-micrograms/kg bolus of Integrelin before angioplasty followed by a 1.0-micrograms.kg-1.min-1 infusion of Integrelin for 4 hours; or a 90-micrograms/kg bolus followed by a 1.0-microgram.kg-1.min-1 infusion of Integrelin for 12 hours. Patients were followed to 30 days for the composite occurrence of myocardial infarction, stent implantation, repeat urgent or emergency percutaneous intervention or coronary bypass surgery, or death. Pharmacodynamic data were obtained in a subset of 31 patients. Administration of a 90-micrograms/kg bolus of Integrelin achieved an 86% inhibition of platelet aggregation, and this inhibition was maintained by a 1.0-microgram.kg-1.min-1 infusion. There was a trend toward reduction in end-point events from 12.2% (placebo) to 9.6% (4-hour infusion) to 4.1% (12-hour infusion), although these differences were not statistically significant (P = .13 for the 12-hour group compared with placebo). Major bleeding occurred in 8%, 8%, and 2% of patients, while minor bleeding was observed in 14%, 33%, and 47% of patients, respectively. There was no difference in bleeding index among groups (1.5, 1.7, and 1.3, respectively), defined as [(change in hematocrit/3)+red blood cell units transfused]. CONCLUSIONS: This first clinical investigation of Integrelin during routine, elective, low- and high-risk coronary intervention supports the potential efficacy of Integrelin in routine coronary interventions. Pharmacodynamic analyses demonstrate that profound and sustained inhibition of platelet function is achieved, although a higher bolus dose may be required. Definitive assessment of efficacy and safety will need to await a large-scale study powered to achieve statistical significance.