'Optimal' directional coronary atherectomy: final results of the Optimal Atherectomy Restenosis Study (OARS)

BACKGROUND

Previous clinical trials of directional coronary atherectomy (DCA) have failed to show significant improvement in early or late outcomes compared with balloon angioplasty (PTCA). The present study tested the hypothesis that more aggressive "optimal" atherectomy could be performed safely to produce larger initial lumen diameters and a lower late restenosis rate.

METHODS AND RESULTS

The present study was a prospective multicenter registry of consecutive patients undergoing optimal DCA of de novo or restenotic lesions in 3.0- to 4.5-mm native coronary arteries. Optimal DCA was defined as using a 7F atherectomy device and adjunctive PTCA if necessary to achieve a < 15% residual stenosis. Six-month angiographic and 1-year clinical follow-up was planned in all patients. A total of 199 patients with 213 lesions met eligibility criteria for enrollment. Short-term procedural success was achieved in 97.5%, with a major complication rate (death, emergency bypass surgery, or Q-wave myocardial infarction [MI]) of 2.5%. There were no early deaths. Non-Q-wave MI (CK-MB > 3 times normal) occurred in 14% of patients. Mean reference vessel diameter was 3.28 mm. Mean diameter stenosis was reduced from 63.5% to a final stenosis of 7%. Late 1-year clinical follow-up revealed one cardiac death and a target lesion revascularization rate of 17.8%. The angiographic restenosis rate at 6 months was 28.9%, with the major predictor of restenosis being a smaller postprocedure lumen diameter.

CONCLUSIONS

Optimal DCA produced a low residual percent diameter stenosis and a lower restenosis rate than seen in previous trials without an increase in early or late major adverse events.

Balloon angioplasty of the internal mammary artery trunk for early postoperative ischemia: a case report

In this case report kinking of the internal mammary artery graft with possible superimposed spasm is described. Angiographic diagnosis was made 72 hrs following coronary artery bypass surgery and the lesion was successfully dilated with balloon angioplasty.

Safety and efficacy of intravenous diltiazem in atrial fibrillation or atrial flutter

This study examines the efficacy of various doses of intravenous diltiazem to control the ventricular response during atrial fibrillation or atrial flutter. Control of the ventricular response of patients with atrial fibrillation and a rapid ventricular response can provide patients with relief of symptoms and improve hemodynamics. Eighty-four consecutive patients with atrial fibrillation or atrial flutter, or both, received an intravenous bolus dose of diltiazem followed by a continuous infusion of diltiazem at 5, 10, and 15 mg/hour. The mean ventricular response and blood pressure were monitored. Overall, 94% of patients (79 of 84) responded to the bolus dose with a > 20% reduction in heart rate from baseline, a conversion to sinus rhythm, or a heart rate < 100 beats/min. Seventy-eight patients received the continuous infusion. After 10 hours of infusion, 47% of patients (confidence interval [CI]: 36%, 59%) had maintained response with the 5 mg/hour infusion, 68% (CI: 57%, 79%) maintained response after the infusion was titrated to 10 mg/hour, and 76% (CI: 66%, 85%) after titration from the 5 and 10 mg/hour infusion to the 15 mg/hour dose. For the 3 diltiazem infusions studied, mean (+/- SD) heart rate was reduced from a baseline value of 144 +/- 14 beats/min to 98 +/- 19, 107 +/- 25, 107 +/- 22, 101 +/- 22, 91 +/- 17, and 88 +/- 18 beats/min at infusion times 0, 1, 2, 4, 8, and 10 hours, respectively. By the end of the infusion, 18% of patients (14 of 78) had conversion to sinus rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)

Mobile cardiac catheterization: comparison with outpatient and inpatient catheterization at tertiary facilities

The study group included 1,553 consecutive patients from areas serviced by our mobile catheterization laboratories: 719 procedures were performed in the mobile unit at their local hospitals, 277 were performed at a tertiary hospital with less than a 24 hr hospital stay, and 557 were performed at a tertiary hospital as inpatients. The indications for mobile catheterization were predominantly atypical chest pain, angina pectoris, or positive treadmill stress test, whereas patients with less than 24 hr hospitalization at the tertiary center had their catheterization performed for additional reasons. The majority of the inpatient indications were for recent myocardial infarction or unstable angina. Using the American College of Cardiology/American Heart Association (ACC/AHA) criteria for outpatient catheterization, the mobile catheterizations were performed safely with a complication rate of only 0.7% compared to a complication rate of 3.1% for inpatients demonstrating that a low risk group of patients can be prospectively identified and catheterized safely in the mobile setting. An extremely high risk group of patients with ongoing unstable angina and recent myocardial infarction was also identified which should undergo catheterization only at a tertiary center.

Mobile cardiac catheterization registry: report of the first 1,001 patients

The purpose of this study was to evaluate prospectively the efficacy and safety of mobile cardiac catheterization. Mobile cardiac catheterization was introduced into clinical practice in 1989, but there has been no systematic study of its performance and safety. A registry was established in 1989 to monitor outcomes with mobile cardiac catheterization and is reported here. Patients were screened for eligibility for mobile cardiac catheterization using the joint AHA/ACC criteria for outpatient angiography. Eligible patients underwent mobile catheterization at eight hospitals within 120 miles of the base tertiary center. Helicopter evacuation services were available at each mobile site. The indications, findings, dispositions, and complications of mobile cardiac catheterization were recorded by means of a checklist, telephone follow-up and chart review. A total of 1,001 consecutive patients were entered into the registry in the first 20 months of operation, including 436 females and 565 males aged 22 to 84 years. Angina (Canadian Classes II-IV) was the most frequent primary indication for catheterization (46.4%), followed by atypical chest pain (36.9%), or a positive exercise stress test (25.6%). Infrequent indications for catheterization included a history of myocardial infarction (5.6%), congestive heart failure (7.1%), arrhythmias (4.1%), and valvular heart disease (0.7%). Catheterization was accomplished in 99.9% of patients. Angiographically normal studies were observed in 22.8%, and mild (< or = 50%) coronary artery disease in 13.6% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of directional atherectomy with coronary angioplasty in patients with coronary artery disease. The CAVEAT Study Group

BACKGROUND

Directional coronary atherectomy is a new technique of coronary revascularization by which atherosclerotic plaque is excised and retrieved from target lesions. With respect to the rate of restenosis and clinical outcomes, it is not known how this procedure compares with balloon angioplasty, which relies on dilation of the plaque and vessel wall. We compared the rate of restenosis after angioplasty with that after atherectomy.

METHODS

At 35 sites in the United States and Europe, 1012 patients were randomly assigned to either atherectomy (512 patients) or angioplasty (500 patients). The patients underwent coronary angiography at base line and again after six months; the paired angiograms were quantitatively assessed at one laboratory by investigators unaware of the treatment assignments.

RESULTS

Stenosis was reduced to 50 percent or less more often with atherectomy than with angioplasty (89 percent vs. 80 percent; P < 0.001), and there was a greater immediate increase in vessel caliber (1.05 vs. 0.86 mm, P < 0.001). This was accompanied by a higher rate of early complications (11 percent vs. 5 percent, P < 0.001) and higher in-hospital costs ($11,904 vs $10,637; P = 0.006). At six months, the rate of restenosis was 50 percent for atherectomy and 57 percent for angioplasty (P = 0.06). However, the probability of death or myocardial infarction within six months was higher in the atherectomy group (8.6 percent vs. 4.6 percent, P = 0.007).

CONCLUSIONS

Removing coronary artery plaque with atherectomy led to a larger luminal diameter and a small reduction in angiographic restenosis, the latter being confined largely to the proximal left anterior descending coronary artery. However, atherectomy led to a higher rate of early complications, increased cost, and no apparent clinical benefit after six months of follow-up.

Preservation of regional myocardial function during coronary angioplasty with an autoperfusion balloon catheter: a case report

Echocardiographic assessment of regional myocardial function was performed during standard balloon coronary angioplasty followed by autoperfusion balloon angioplasty of a proximal left anterior descending artery stenosis. Septal and apical akinesis occurred within 60 seconds of standard balloon inflation, but regional function was well preserved during prolonged autoperfusion balloon inflation.

Myocardial protection during coronary angioplasty with an autoperfusion balloon catheter in humans

An autoperfusion balloon catheter was developed to allow passive myocardial perfusion during inflation through a central lumen and multiple side holes in the shaft proximal and distal to the balloon. We report its safety and efficacy in 11 patients undergoing elective angioplasty to a single coronary lesion. Each lesion was dilated three times with the autoperfusion inflation bracketed between two inflations by standard angioplasty catheters. Chest pain score, 12-lead electrocardiogram, heart rate, and mean aortic pressure were recorded before each inflation and at 1-minute intervals after inflation. Inflation duration during autoperfusion angioplasty (513 +/- 303 seconds) was longer than for the pre- (107 +/- 55 seconds, p = 0.0004) and post- (139 +/- 71 seconds, p = 0.0006) standard dilatations. The maximum ST-segment elevation and depression in any lead during autoperfusion angioplasty (0.3 +/- 0.5 and 0.6 +/- 0.8 mm) was significantly less than for the pre- (2.4 +/- 1.7 mm, p = 0.002 and 2.2 +/- 1.3 mm, p = 0.0004) or post- (1.9 +/- 1.3 mm, p = 0.002 and 1.6 +/- 1.3 mm, p = 0.018) standard dilatations at the same point in time. Maximal chest pain score during autoperfusion (3.2 +/- 3.5) was lower than for the pre- (6.1 +/- 2.1, p = 0.003) but not the post- (5.2 +/- 3.1, p = 0.07) standard angioplasty. All 11 patients underwent successful, uncomplicated procedures. We conclude that this autoperfusion catheter significantly reduces ischemic symptoms and signs during coronary angioplasty, allowing prolonged periods of balloon inflation.

The ventilatory threshold: quantitative analysis of reproducibility and relation to arterial lactate concentration in normal subjects and in patients with chronic congestive heart failure

The present study evaluates optimal ventilatory criteria and exercise protocols for determining the ventilatory threshold, and assesses the day-to-day reproducibility of the ventilatory threshold and its relation to peak oxygen uptake VO2 and blood lactate concentration in normal subjects and patients with stable chronic congestive heart failure (CHF). Eighteen normal subjects and 18 patients underwent rapid (1-minute stage) and gradual (3-minute stage) bicycle exercise tests on consecutive days. The ventilatory threshold was determined from computer-generated printouts of expired gas variables measured breath by breath. Interobserver variability of ventilatory threshold was small in both normal (0.66 +/- 0.85 ml/min/kg) and CHF patients (0.50 +/- 0.46 ml/min/kg). Variability in the normal subjects was lower for the rapid exercise protocol (0.66 +/- 0.85 ml/min/kg) than the gradual protocol (1.72 +/- 1.63 ml/min/kg) (p less than 0.05), but both protocols produced similar results in the CHF group. Day-to-day reproducibility of ventilatory threshold was high (r = 0.91, standard error of the estimate 1.74 ml/min/kg) and was similar to that of peak VO2 (r = 0.95, standard error of the estimate 3.31 ml/min/kg). The use of co-plotted ventilatory equivalents for oxygen and carbon dioxide yielded ventilatory threshold values comparable to values obtained by using multiple parameters (r = 0.94, p less than 0.0001). Although the ventilatory threshold did not predict a precise lactate level for individual subjects, the lactate increment at the ventilatory threshold occurred within a narrow range in both normal subjects and patients with CHF; the increase was 7.5 +/- 4.5 mg/dl and 7.7 +/- 4.1 mg/dl, respectively, indicating a relation to initial increases in blood lactate.

Survival and cardiac event rates in the first year after emergency coronary angioplasty for acute myocardial infarction

One year survival and event-free survival rates were analyzed in 342 patients with acute myocardial infarction who were consecutively enrolled in a treatment protocol of early intravenous thrombolytic therapy followed by emergency coronary angioplasty. Ninety-four percent of the patients achieved successful reperfusion, including 4% with failed angioplasty whose perfusion was maintained by means of a reperfusion catheter before emergency bypass surgery. The procedural mortality rate was 1.2% and the total in-hospital mortality rate was 11%. Ninety-two percent of surviving nonsurgical patients who underwent repeat cardiac catheterization were discharged from the hospital with an open infarct-related artery. The related cumulative 1 year survival rate for all patients managed with this treatment strategy was 87%, and the cardiac event-free survival rate was 84%. The 1 year survival for hospital survivors was 98% and the infarct-free survival rate was 94%. Multivariable analysis identified the following factors as independent predictors of subsequent cardiovascular death: cardiogenic shock, greater age, lower ejection fraction, female gender and a closed infarct-related vessel on the initial coronary angiogram. Among patients with cardiogenic shock, despite a 42% in-hospital mortality rate, only 4% died during the first year after hospital discharge. Similarly, the in-hospital and 1 year postdischarge mortality rates were 19 and 4%, respectively, for patients with an initial ejection fraction less than 40, and 25 and 3%, respectively, for patients greater than 65 years. An aggressive treatment strategy including early thrombolytic therapy, emergency cardiac catheterization, coronary angioplasty and, when necessary, bypass surgery resulted in a high rate of infarct vessel patency.(ABSTRACT TRUNCATED AT 250 WORDS)

The risk for systemic embolization associated with percutaneous balloon valvuloplasty in adults. A prospective comprehensive evaluation

STUDY OBJECTIVE

To prospectively investigate the evidence for embolic phenomena associated with percutaneous mitral and aortic valvuloplasty.

DESIGN

Prospective, consecutive case series before and after balloon valvuloplasty.

SETTING

Referral center hospital and cardiac catheterization laboratory.

PATIENTS

Consecutive sample of 32 patients having balloon valvuloplasty for critical symptomatic stenosis of the mitral or aortic valve. Twenty-six patients had aortic stenosis; 6 had mitral stenosis.

INTERVENTION

Computed tomography of the head, funduscopy, and electrocardiography were done in all patients before and after valvuloplasty. Cardiac isoenzymes were measured serially in 19 patients.

MEASUREMENTS AND MAIN RESULTS

Previous cerebral infarction was seen in nine patients, with three showing a new abnormality after aortic valvuloplasty. In one of these patients a funduscopic hemorrhage was detected by photography. Total creatinine kinase and MB fraction were elevated in 1 of 19 patients. Serial electrocardiograms were unchanged in all patients.

CONCLUSIONS

The incidence of cerebral neurologic events and myocardial injury are acceptably low after balloon valvuloplasty of calcific aortic and mitral stenosis. Both episodes of symptomatic cerebral infarction occurred in patients with apparent bicuspid aortic valvular stenosis, suggesting that calcific bicuspid aortic stenosis may be associated with more neurologic events after aortic valvuloplasty.

Late restenosis after emergent coronary angioplasty for acute myocardial infarction: comparison with elective coronary angioplasty

The late restenosis rate after emergent percutaneous transluminal coronary angioplasty for acute myocardial infarction was assessed by performing outpatient follow-up cardiac catheterization in 79 (87%) of 91 consecutive patients who had been discharged from the hospital with a successful coronary angioplasty. The majority of patients (90%) received high dose intravenous thrombolytic therapy with streptokinase in addition to angioplasty. Similar follow-up data were obtained in 206 (90%) of 228 consecutive patients who had successful elective angioplasty during the same period. The interval from angioplasty to follow-up was 28 +/- 9 weeks for the myocardial infarction group and 30 +/- 11 weeks for the elective group. Baseline clinical variables were similar for both the myocardial infarction and elective groups except for a higher percentage of men in the infarction group (81 versus 63%, p = 0.001). The number of coronary lesions undergoing angioplasty and the incidence of intimal dissection were similar, but multivessel angioplasty was more common in the elective group (13 versus 4%, p = 0.02). The rate of in-hospital reocclusion was higher in the patients receiving angioplasty for myocardial infarction (13 versus 2%, p = 0.0001). At the time of late follow-up after hospital discharge, the patients with myocardial infarction were more often asymptomatic (79 versus 55%, p = 0.0001), and the rate of angiographic coronary restenosis was lower for the infarction group both overall (19 versus 35%, p = 0.006) and when multivessel angioplasty patients were excluded (19 versus 33%, p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary perfusion during acute myocardial infarction with a combined therapy of coronary angioplasty and high-dose intravenous streptokinase

Two hundred and sixteen patients with acute myocardial infarction were treated with immediate infusion of high-dose (1.5 million units) intravenous streptokinase followed by emergency coronary angioplasty. The infarct lesion was crossed and dilated in 99% and persistent coronary perfusion after the procedure was achieved in 90% (including 3% with significant residual stenosis). Total in-hospital mortality was 12%. Multivariable analysis showed a higher hospital mortality with cardiogenic shock (41% vs 5% without shock), older age, lower left ventricular ejection fraction, and female sex. Final patency of the infarct-related vessel was determined by follow-up in-hospital cardiac catheterization. Coronary reocclusion occurred in 11% (symptomatic in 7%, treated with emergency angioplasty or bypass surgery; silent in 4%, treated medically). Of the surviving patients with successful initial establishment of infarct vessel patency, 94% were discharged from the hospital with an open infarct artery or a bypass graft to the infarct vessel. There was significant improvement in both ejection fraction (44% to 49%; p less than .0001) and regional wall motion in the infarct zone (-3.0 SD to -2.4 SD; p less than .0001) among patients with persistent coronary perfusion and insignificant residual stenosis at the time of the follow-up cardiac catheterization. Thus, a treatment strategy for acute myocardial infarction that includes immediate administration of streptokinase followed by emergency coronary angioplasty, and coronary bypass surgery when necessary, results in a high rate of early and sustained patency of the infarct-related vessel.

Survival in severe left ventricular failure treated with the new nonglycosidic, nonsympathomimetic oral inotropic agents

Survival in severe left ventricular failure is poor but has not been widely assessed since the introduction of several new nonglycosidic, nonsympathomimetic oral inotropic agents for long-term therapy. We examined retrospectively the survival of 82 patients with severe left heart failure during long-term treatment with oral milrinone (17 patients), posicor (12 patients), enoximone (47 patients), and piroximone (6 patients). Sixty-five patients were in New York Heart Association (NYHA) functional class 4, 15 patients were in class 3, and two patients were in class 2. There were 57 patients with ischemic and 25 patients were in class 2. There were 57 patients with ischemic and 25 patients with nonischemic etiology of left heart failure. Most patients were referred for inotropic therapy after failing to respond to conventional agents, including vasodilators. However, in almost all patients, marked hemodynamic and clinical improvement occurred initially. Overall survival was 36 percent at six months, the majority of deaths occurring during the first three months. Survival in relation to etiology of heart failure showed a trend toward increased mortality in patients associated with ischemic heart disease vs non-ischemic dilated cardiomyopathy. Sudden death mortality was also higher in the ischemic group (28 percent at six months vs 5 percent at six months; p less than 0.05). There was a trend toward reduced sudden death mortality in patients on antiarrhythmic agents during inotropic therapy (p = 0.06). We conclude that overall survival in symptomatic patients with severe left ventricular failure remains very low during long-term therapy with several new oral inotropic agents. Sudden death appears higher in patients with an ischemic etiology during therapy with these agents.

Milrinone in congestive heart failure: acute and chronic hemodynamic and clinical evaluation

Acute and chronic hemodynamic and clinical responses to milrinone, a new oral inotrope-vasodilator agent, were evaluated prospectively in 37 patients with severe congestive heart failure. The majority of patients (n = 31) had not responded to prior vasodilator therapy, with a substantial number (n = 8) requiring intravenous inotropic support at the time of initial study. All patients showed acute hemodynamic improvement with oral milrinone, and an optimal maintenance dose was chosen for each patient during dose-ranging studies (average dose 48 mg/day). Milrinone was discontinued before follow-up hemodynamic study in 12 patients (because of worsening congestive heart failure in 6 patients, sudden death in 3 patients, arrhythmia in 1 patient and refusal by 2 patients). Hemodynamic effects of milrinone both acutely and after chronic therapy (average 37 days) were compared in the remaining 25 patients. Acutely, mean cardiac index increased from 1.9 +/- 0.5 to 2.5 +/- 0.5 liters/min per m2 (p less than 0.001), and mean pulmonary capillary wedge pressure decreased from 28 +/- 9 to 18 +/- 8 mm Hg (p less than 0.001). When oral milrinone was readministered after chronic therapy, mean cardiac index increased from 1.9 +/- 0.5 to 2.5 +/- 1.7 liters/min per m2 (p less than 0.001), and pulmonary capillary wedge pressure decreased from 27 +/- 8 to 20 +/- 8 mm Hg (p less than 0.001) at 1 hour. New York Heart Association functional class improved in 18 of the 25 patients treated over a long-term period (mean 5.5 +/- 2.3 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between para-aminohippurate secretion and cellular morphology in rabbit proximal tubules

Previous studies in the mammalian proximal tubule have suggested that para-aminohippurate (PAH) secretion is approximately threefold greater in the straight segment, or pars recta, than in the convoluted segment, or pars convoluta. However, the possibility that the site of maximal PAH secretion might be related better to particular tubule segments as identified by cell type had not been explored. In addition, the presence or absence of differences in PAH secretion between morphologically identical regions of superficial (SF) vs. juxtamedullary (JM) proximal tubules has not been examined. These issues were studied using a combination of histologic methods and measurement of [(3)H]PAH secretion in isolated perfused tubules. Measurements of microdissected SF and JM proximal tubules from young and adult rabbits revealed that SF proximal tubules were slightly but significantly longer than JM tubules ([young rabbits: SF, 8.69+/-SE 0.14 mm vs. JM, 7.97+/-SE 0.13 mm; P < 0.01] [adult rabbits: SF, 10.61+/-SE 0.28 mm; JM, 9.17+/-SE 0.19 mm; P < 0.001]). Light and electron microscopy revealed three sequential segments (S(1), S(2), and S(3)) along the length of SF and JM proximal tubules as defined by cell type. PAH secretion was measured in each of these three segments by the isolated perfused tubule technique. Net PAH secretion in fmol/mm per min in SF proximal tubules was: S(1), 281+/-SE 21; S(2), 1,508+/-SE 104; S(3), 318+/-SE 46. Corresponding values in JM proximal tubules were 353+/-SE 31, 1,391+/-SE 72, and 188+/-SE 23. Net PAH secretion did not differ between comparable segments of SF and JM proximal tubules. It is concluded that differences in PAH secretion along the proximal tubule correlate best with cell type rather than the arbitrary division of the proximal tubule into pars convoluta and pars recta according to its external configuration. Evidence of functional heterogeneity between comparable segments of SF and JM proximal tubules was not observed.