Outcome > or = 10 years after successful percutaneous transluminal coronary angioplasty

Patients (n = 611) after successful percutaneous transluminal coronary angioplasty were prospectively followed over 10 to 16 years for major adverse events. The effect of gender, extent of coronary artery disease, left ventricular dysfunction, and age on occurrence of adverse events were analyzed in detail. The incidence of death, Q-wave myocardial infarction, and coronary bypass surgery was 23.1%, 3.9%, and 32.7%, respectively. Men and women had similar mortality (p = 0.13) and Q-wave myocardial infarction (p = 0.57), but men had more coronary bypass surgery (p = 0.06). Patients with multivessel disease had higher mortality (p < 0.0001), and patients with 3-vessel disease had a higher incidence of Q-wave myocardial infarction (p = 0.04) and coronary bypass surgery (p < 0.001). Left ventricular dysfunction was associated with higher mortality (p < 0.0001) and coronary bypass surgery (p = 0.045), but not Q-wave myocardial infarction (p = 0.99). Mortality was higher in elderly patients (p < 0.0001), but the incidence of Q-wave myocardial infarction was similar (p = 0.64). Older patients underwent coronary bypass surgery less often (p = 0.004). By multivariate analysis, only the extent of coronary disease (relative risk [RR] 1.71, confidence interval [CI] 1.34 to 2.19; p = 0.0001), diabetes mellitus (RR 1.82, CI 1.28 to 2.59; p = 0.001), hypertension (RR 1.30, CI 1.08 to 1.96, p = 0.009), male gender (RR 1.30, CI 0.99 to 1.71, p = 0.058), and prior myocardial infarction (RR 1.44, CI 1.14 to 1.81, p = 0.002) independently influenced the incidence of major adverse events. We conclude that it is possible to identify patients with worse long-term prognosis after percutaneous transluminal coronary angioplasty based on clinical and angiographic parameters.

The changing face of coronary interventional practice. The Mayo Clinic experience

BACKGROUND

Devices designed to facilitate or replace conventional percutaneous transluminal coronary angioplasty have been introduced in recent years.

OBJECTIVES

To characterize the changes in percutaneous coronary interventional practice over 16 years and to assess the relative use of these new devices.

METHODS

We performed a retrospective analysis of all patients who underwent percutaneous coronary revascularization at Mayo Clinic, Rochester, Minn, during a 16-year period (1980-1995) and characterized the changes in procedural and clinical factors.

RESULTS

The number of coronary interventional procedures performed increased from 38 in 1980 to 1284 in 1995. Atherectomy and laser angioplasty were incorporated in 1988; their use peaked in 1994 (17% of procedures) but decreased to 9.9% by 1995. In contrast, the use of intracoronary stents has increased steadily since 1990. By 1995, intracoronary stents were placed in 48.2% of procedures. The success rate improved from 55.3% in 1980 to 91.4% in 1995, although patients were older (51 +/- 10 [mean +/- SD] years in 1980 vs 63 +/- 12 years in 1995), had more extensive coronary artery disease (0% with multivessel disease in 1980 vs 47.4% in 1995), had more complex lesions, and often underwent intervention in the peri-infarction setting (2.6% of procedures in 1980 vs 17% in 1995). The rate of referral to emergency coronary bypass surgery after percutaneous procedures declined from 5.2% in 1980 to 0.4% in 1995.

CONCLUSIONS

Current coronary interventional practice is expanding and improving. In contrast to intracoronary stents that have greatly affected current practice, other new devices are used infrequently. Conventional angioplasty, with or without intracoronary stents, remains the dominant treatment strategy.

Interventional cardiology and intracoronary stents--a changing practice: approved vs. nonapproved indications

Our objective was to document change in stent usage in a single practice over time and to study "off-label" compared to Food and Drug Administration (FDA)-approved indications. Although only two intracoronary stents have been approved by the FDA, the relatively limited approved indications do not account for the dramatic increase in stent implantation. This increase has important implications for patient health care delivery. This study of stent usage in a single center over a 36-mo period included all patients treated with coronary stents at the Mayo Clinic from January 1993-December 1995, and evaluated the relative difference in frequency between "off-label" and FDA-approved indications for implantation. During the 36-mo period of study, 3,614 interventional procedures were done and one or more stents were placed in 25.4% of patients. The proportion of patients receiving stents increased throughout this time: during the first 6-mo period, stents were placed in 6.2% of procedures; during the last 6-mo period, stents were placed in 46.3% of procedures, an eightfold increase. During the final 6 mo, an unapproved device or an unapproved indication for an approved device constituted 59.4% of all stent procedures. In addition, use of the non-FDA-approved adjunctive treatment regimen without warfarin increased from 2.9% in the first 6-mo period of observation to 82.7% in the last 6 mo. The use of stents increased strikingly over a 36-mo period, from 6% to 46% of all procedures. The majority of implantations were performed either for an "off-label" unapproved indication or with an unapproved device.

Quantitative evaluation of regional myocardial perfusion using fast X-ray computed tomography

Clinical quantitation of regional myocardial perfusion using a minimally invasive and easily applied technique could allow for ready quantitation of the functional significance of coronary disease, allow for further understanding of flow reserve in various cardiomyopathic and hemodynamic overload (pressure versus volume) conditions, and possibly provide basic information needed regarding the development and clinical significance of coronary collateral vessels and diseases of the myocardial microcirculation. Electron beam CT (EBCT) is a unique cardiac imaging modality that allows for rapid acquisition tomographic slices of the heart with excellent spatial resolution. It has been demonstrated to provide accurate measurements of cardiac anatomy, biventricular function, myocardial mass, and estimates of mural atherosclerotic plaque burden via quantification of coronary calcium. The application of classical indicator techniques for use by fast x-ray computed tomography techniques such as electron beam CT has been shown to allow quantitative analysis of regional myocardial perfusion throughout the myocardium. Initial studies using central intravenous contrast injection in experimental animals showed a close correlation of regional myocardial perfusion as quantitated by electron beam CT with measurements using radiolabeled microspheres at resting and moderately increased flow states. At high flow states, however, electron beam CT significantly underestimated absolute myocardial perfusion and thus myocardial flow reserve. Using another fast CT device, the Dynamic Spatial Reconstructor (DSR), concepts of intramyocardial vascular blood volume and its relation to myocardial flow have been established. By adapting these concepts to electron beam CT scanning and accounting for the increase in intramyocardial vascular blood volume at vasodilatation, the ability to correctly quantitate perfusion states up to approximately 400 mL.min-1. 100 g-1 using central intravenous contrast administration was demonstrated. This implies that studies can be done with intravenous injection methods for characterization of regional myocardial perfusion up to the normal flow reserve of approximately 4:1. Important physiologic and clinical abnormalities in flow reserve generally result in a ratio < 3:1. Electron beam CT offers the capability to quantitate regional myocardial perfusion in both the clinical and research setting. Of particular interest is the ability to provide quantitative regional myocardial perfusion which can be coupled to the evaluation of cardiac anatomy and function as well as mural coronary atherosclerotic calcium burden during the same scanning session. Thus, electron beam CT has the potential to become a valuable, minimally invasive clinical tool for comprehensive analysis of cardiac function and coronary status.

Sex and test verification bias. Impact on the diagnostic value of exercise echocardiography

BACKGROUND

The use of exercise echocardiography for the diagnosis of coronary artery disease (CAD) has been validated in pilot studies but is not documented in clinical practice and in women comparatively with men. The objectives of this study were to determine the effects of sex and of test verification bias on the diagnostic performance of exercise echocardiography.

METHODS AND RESULTS

Three thousand six hundred seventy-nine consecutive patients (1714 women, 1965 men) who underwent an exercise echocardiographic study were studied; the observed sensitivity, specificity, and correct classification rate were calculated among 340 patients (244 men, 96 women) who underwent angiography; to study the effect of test verification bias, sensitivity and specificity were estimated for all patients who underwent exercise echocardiography including those not referred to angiography. In the angiographic group, the prevalence of CAD was 60% in women and 80% in men. The observed sensitivity and specificity of exercise echocardiography was 78% and 44% in men and 79% and 37% in women. After adjustment for test verification bias, the estimated sensitivity was lower in women (32% versus 42% in men), whereas specificity was similar in both sexes. The positive predictive value was lower in women (66%) compared with men (84%).

CONCLUSIONS

In clinical practice, test verification bias results in a lower observed specificity and a higher sensitivity of exercise echocardiography. In women, positive predictive value and adjusted sensitivity are lower compared with that in men.

Validation of a new UNIX-based quantitative coronary angiographic system for the measurement of coronary artery lesions

We describe a method of validation of computerized quantitative coronary arteriography and report the results of a new UNIX-based quantitative coronary arteriography software program developed for rapid on-line (digital) and off-line (digital or cinefilm) analysis. The UNIX operating system is widely available in computer systems using very fast processors and has excellent graphics capabilities. The system is potentially compatible with any cardiac digital x-ray system for on-line analysis and has been designed to incorporate an integrated database, have on-line and immediate recall capabilities, and provide digital access to all data. The accuracy (mean signed differences of the observed minus the true dimensions) and precision (pooled standard deviations of the measurements) of the program were determined x-ray vessel phantoms. Intra- and interobserver variabilities were assessed from in vivo studies during routine clinical coronary arteriography. Precision from the x-ray phantom studies (6-In. field of view) for digital images was 0.066 mm and for digitized cine images was 0.060 mm. Accuracy was 0.076 mm (overestimation) for digital images compared to 0.008 mm for digitized cine images. Diagnostic coronary catheters were also used for calibration; accuracy.varied according to size of catheter and whether or not they were filled with iodinated contrast. Intra- and interobserver variabilities were excellent and indicated that coronary lesion measurements were relatively user-independent. Thus, this easy to use and very fast UNIX based program appears to be robust with optimal accuracy and precision for clinical and research applications.

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.

Influence of procedural success on immediate and long-term clinical outcome of patients undergoing percutaneous revascularization of occluded coronary artery bypass vein grafts

OBJECTIVES

This study sought to determine whether successful recanalization of an occluded vein graft is associated with improvement in long-term clinical outcome.

BACKGROUND

Coronary angioplasty of occluded vein grafts is associated with a lower initial success rate and a higher complication rate than angioplasty of vein grafts with subtotal stenoses and native coronary arteries. Whether successful angioplasty improves clinical outcome is unknown.

METHODS

We analyzed 77 consecutive patients who underwent angioplasty of an occluded saphenous vein coronary artery bypass graft between August 1983 and June 1994. Patients with a myocardial infarction in the previous 24 h were excluded from the study.

RESULTS

The mean age of the study cohort was 65 years; the mean (+/- SD) age of the treated grafts was 7.5 +/- 3.9 years. As an adjunct to balloon angioplasty, stents were used in 9% of procedures, laser in 30%, and atherectomy in 16%, and thrombolytic therapy was administered in 23% of patients. The angioplasty success rate was 71%. Major complications within 30 days of the procedure included death in 5.2% of patients, Q wave myocardial infarction in 1.3% and repeat bypass surgery in 7.8%; these events occurred with similar frequency in patients in whom angiographic success was and was not achieved. Kaplan-meier analysis comparing patients in whom angioplasty was successful (n = 55) and not successful (n = 22) revealed no differences in survival or occurrence of myocardial infarction or recurrent severe angina between the two groups in the 3 years after the procedure. Univariate analysis identified the age of the graft and use of newer interventional devices as predictors of death or myocardial infarction during this time period; procedural success was not associated with freedom from these adverse events after adjusting for these variables.

CONCLUSIONS

Angioplasty of occluded vein grafts is associated with a low initial success rate and a high complication rate. Successful angioplasty does not appear to reduce the occurrence of adverse events in the 3 years after the procedure.

Seizures and the long-QT syndrome

We describe a case of idiopathic long-QT syndrome in a 4-year-old Hispanic girl. She had been seen previously at an outside hospital for possible new-onset seizure disorder but was brought to our emergency department after sustaining an unwitnessed fall. Her ECG was significant for changes consistent with long-QT syndrome. Emergency physicians should understand the necessity of electrocardiography in all pediatric patients who present with multiple spontaneous falls, episodes of dizziness, new-onset seizure activity and syncopal episodes.

Coronary angioplasty and intracoronary thrombolysis are of limited efficacy in resolving early intracoronary stent thrombosis

OBJECTIVES

This study sought to evaluate treatment of early intracoronary stent thrombosis.

BACKGROUND

Although refinements in intracoronary stent implantation technique and pharmacologic treatment have reduced the frequency of early stent thrombosis, stent thrombosis remains a feared complication of this procedure. Optimal treatment for stent thrombosis is still undefined.

METHODS

Twenty-nine patients (44 stents) with early (< or = 30 days) coronary stent thrombosis over a 5-year period at our institution were identified. Treatment and outcome of stent thrombosis were analyzed.

RESULTS

Mean (+/- SD) time from implantation to stent thrombosis was 6.1 +/- 5 days. Twenty-three patients were treated with catheter-based therapies (angioplasty alone in 14, angioplasty and intracoronary urokinase in 7, intracoronary urokinase alone in 2). Flow was restored without residual thrombus in 11 (48%) of the catheter-treated patients (6 of 14 with angioplasty alone, 4 of 7 with angioplasty and urokinase, 1 with urokinase alone). Of the 23 patients, 2 died despite restoration of anterograde flow, and 9 were referred for emergent or urgent bypass surgery because of residual thrombus and refractory angina despite restoration of blood flow. Of the remaining six patients, five were treated medically and one with coronary bypass surgery; three died. Acute myocardial infarction evolved in 26 patients (90%), including 20 (87%) of the 23 catheter-treated patients.

CONCLUSIONS

Stent thrombosis is associated with severe adverse outcomes. Although catheter-based therapies are effective in restoring patency in a majority of patients, patients are referred frequently for coronary bypass surgery because of residual thrombus and refractory angina. These findings suggest that alternative or adjunctive therapies for stent thrombosis are needed.

Impact of stent size and indication for stent placement on immediate outcome

The immediate outcome of 271 procedures involving the intracoronary implantation of 305 stents was determined. Data were analyzed with regard to indication for stenting and stent size. Elective indication was associated with a higher success rate than emergency indication (95.6% vs. 86.6%, P = 0.013) and a lower Q-wave infarction rate (0 vs. 6.4%, P = 0.006). Univariate analysis showed that the odds ratio for procedural success was significantly favored by elective indication (3.37, P = 0.018) but was unrelated to stent size (1.10, P = 0.087). These findings were confirmed on multivariate analysis. The likelihood of Q-wave infarction was lower for elective placement (P = 0.0008) but was not related to size. Requirement for emergency bypass surgery, incidence of subacute closure, and death were not related to indication or to stent size on either univariate or multivariate analysis. Therefore, the immediate outcome of stent placement is related to the indication for stenting, but not to the size of stent implanted. Procedural success is significantly favored by elective indication.

Are there gender differences or issues related to angiographic imaging of the coronary arteries?

The use of coronary angiography and coronary interventions in women with suspected coronary artery disease has recently come under close scrutiny. Clear differences in the utilization of these procedures, including coronary artery bypass graft (CABG) surgery have led to concerns that a bias may exist against the use of these procedures in women. Alternative explanations of these perceived practice differences have focused on their propriety based on patients' ages, underlying disease severity, expected prevalence of coronary disease and comorbid conditions rather than physician bias. The possibility that these procedures are over utilized in men has also been suggested. Pertinent to this debate are historical observational data suggesting that women may be at higher risk of major complications of coronary interventions and CABG surgery. Because coronary artery disease is the most frequent cause of death among women in the United States, there is some sociopolitical urgency in addressing these important concerns. This article reviews the use and findings of diagnostic coronary angiography in women with suspected coronary artery disease. Specific risks to women who have coronary angiography performed are also discussed. Finally, the outcome of percutaneous coronary revascularization procedures in women compared to men is discussed.

Endothelin in coronary endothelial dysfunction and early atherosclerosis in humans

BACKGROUND

The endothelium modulates vascular tone through release of vasodilating substances, such as endothelium-derived relaxing factors, and vasoconstricting substances, such as endothelin. Endothelin concentrations are elevated in humans with atherosclerosis and in hypercholesterolemic pigs. Furthermore, the endothelium-dependent vasodilator acetylcholine increases endothelin in hypercholesterolemia in association with coronary vasoconstriction. The present study was designed to test the hypotheses that coronary endothelial dysfunction in humans is characterized by enhanced coronary and circulating endothelin and that the vasoconstriction associated with acetylcholine results in further release of coronary endothelin.

METHODS AND RESULTS

Coronary and circulating endothelin concentrations were measured at baseline and during intracoronary acetylcholine administration in 20 patients undergoing diagnostic coronary angiography. Patients were divided into two groups on the basis of their response to intracoronary acetylcholine. Group 1 (n = 7) demonstrated a normal vasodilatory response, but group 2 (n = 13) demonstrated coronary vasoconstriction. Baseline coronary and circulating endothelin concentrations (as determined by coronary sinus and femoral artery measurements, respectively) were higher in patients who responded to acetylcholine with coronary vasoconstriction (group 2) than in group 1 patients (coronary sinus, 15.9 +/- 1.0 pg/mL versus 7.1 +/- 1.0 pg/mL; femoral, 14.1 +/- 0.9 pg/mL versus 6.8 +/- 1.0 pg/mL, respectively; P < .01). In response to intracoronary acetylcholine, a further increase in coronary endothelin was observed only in group 2; this increase correlated with changes in coronary artery diameter.

CONCLUSIONS

This study demonstrates that endothelin immunoreactivity is enhanced in the coronary and systemic circulation in humans with coronary endothelial dysfunction. Moreover, acetylcholine further increased coronary endothelin concentration in patients with coronary endothelial dysfunction and was associated with coronary vasoconstriction. These observations strongly support a role for endothelin as an early participant in and marker for coronary endothelial dysfunction in humans.

Time to reperfusion and other procedural characteristics of emergency coronary artery bypass surgery after unsuccessful coronary angioplasty

A databank search was performed and 148 consecutive patients (mean age 59.5 +/- 10.4 years) were identified who underwent emergency coronary artery bypass surgery at the Mayo Clinic between November 20, 1979, and February 12, 1992, immediately after unsuccessful coronary angioplasty. At the end of the angioplasty procedure, there was no anterograde coronary blood flow in the treated artery in 54%, ongoing chest pain in 78%, and hemodynamic compromise requiring intravenous vasopressor therapy in 25% of patients; 127 patients (86%) had at least 1 of these adverse characteristics. After leaving the catheterization laboratory, the median time to arrival in the operating room was 12 minutes. Median time from arrival in the operating room to initiation of cardiopulmonary bypass was 86 minutes, to administration of cardioplegia was 98 minutes, and to removal of the aortic cross-clamp was 135 minutes. In-hospital mortality was 11%, and 18% developed nonfatal Q-wave myocardial infarction. Thus, significant time is required to achieve surgical reperfusion after unsuccessful coronary angioplasty.

Aminoalkylindoles: structure-activity relationships of novel cannabinoid mimetics

Aminoalkylindoles (AAIs) are a novel series of cannabinoid receptor ligands. In this report we disclose the structural features of AAIs which are important for binding to this receptor as measured by inhibition of binding of [3H]Win 55212-2 (5). Functional activity in the mouse vas deferens is also noted and used to distinguish agonists from potential antagonists. The key structural features for potent cannabinoid activity in this series are a bicyclic (naphthyl) substituent at the 3-position, a small (H) substituent at the 2-position, and an aminoethyl (morpholinoethyl) substituent at the 1-position. A 6-bromo analog, Win 54461 (31), has been identified as a potential cannabinoid receptor antagonist. Modeling experiments were done to develop a pharmacophore and also to compare AAI structures with those of classical cannabinoids. The fact that the cannabinoid AAIs arose out of work on a series of cyclooxygenase inhibitors make sense now that an endogenous cannabinoid ligand has been identified which is a derivative of arachidonic acid. Because of their unique structures and physical properties, AAIs provide useful tools to study the structure and function of the cannabinoid receptor(s).

Long-term outcome of women compared with men after successful coronary angioplasty

BACKGROUND

Women who undergo coronary angioplasty have a higher in-hospital mortality than men, although much of this difference can be accounted for by their poorer clinical characteristics at the time of their procedures. However, whether or not there are important long-term differences in outcome between women and men after coronary angioplasty is not clear.

METHODS AND RESULTS

A retrospective analysis was performed of 3027 consecutive patients (824 women and 2203 men) who underwent successful angioplasty and who have been followed continuously for a mean of 5.5 years (range, 0.5 to 14 years). Follow-up is 100% complete. Event-free survival was assessed by the Kaplan-Meier method, and clinical end points were also examined by Cox proportional-hazards models to account for important baseline differences when appropriate. There was a trend toward lower survival among women during follow-up, but this was not significant (P = .06). The relative risk of death among women compared with men after adjustment for baseline differences was 0.94 (CI, 0.76 to 1.15; P = NS). No significant sex differences in occurrence of Q-wave myocardial infarction were observed. Women were less likely to remain free of angina after 10 years (34% versus 37%, respectively; P = .008), but after adjustment for baseline differences, this difference was not significant (relative risk of angina, 1.07; CI, 0.95 to 1.21). Women tended to have less coronary artery bypass surgery performed during follow-up (P = .06); adjusting for baseline differences made this difference more significant (relative risk, 0.79; CI, 0.64 to 0.96; P = .02). Among patients who were not treated in the setting of acute infarction, no sex differences in survival and freedom from myocardial infarction were noted.

CONCLUSIONS

After successful coronary angioplasty, the long-term prognosis for women is excellent and is similar to that observed in men. Risk-adjusted survival did not differ significantly between the sexes, but less frequent use of subsequent surgical revascularization was observed in women.

Referral for coronary artery revascularization procedures after diagnostic coronary angiography: evidence for gender bias?

OBJECTIVES

We sought to determine whether there is a gender bias in the selection of patients for coronary revascularization once the severity of the underlying coronary artery disease has been established with angiography.

BACKGROUND

It has been suggested that women with coronary artery disease are less likely to be referred for coronary angiography and coronary artery bypass surgery than men. Whether such a referral bias for revascularization procedures, including coronary angioplasty, is present once angiography has been performed is not clear.

METHODS

We retrospectively analyzed 22,795 patients with suspected coronary artery disease who underwent coronary angiography between 1981 and 1991 and compared the numbers of women and men who underwent either coronary artery bypass surgery or coronary angioplasty within 30 days of coronary angiography.

RESULTS

Angiography revealed significant (one-vessel or more) disease in 15,455 patients (52% of women, 76% of men). Despite worse symptoms, women had less extensive coronary disease than men as judged by the number of vessels diseased. Women were also more likely to have other co-morbid diseases. An equal proportion of women (54%) and men underwent revascularization procedures. After adjustment for baseline differences and age, differences in the two individual revascularization strategies were very small: More women tended to have coronary angioplasty ([absolute difference +/- 1 SD] + 3.3 +/- 0.7%, p < 0.0001), but fewer had coronary artery bypass surgery than men (-2.5 +/- 0.8%, p = 0.003). When the two revascularization strategies were considered together, there was no significant gender difference in overall adjusted use of revascularization (+ 0.8 +/- 0.9%, p = 0.41).

CONCLUSIONS

Once diagnostic coronary angiography had been performed, no major differences in the overall utilization of revascularization procedures were noted for women compared with men.

Orally bioavailable benzisothiazolone inhibitors of human leukocyte elastase

Human leukocyte elastase (HLE) has been proposed as a primary mediator of pulmonary emphysema and other inflammatory airway diseases. HLE is capable of cleaving many proteins, including elastin, other components of connective tissue, certain complement proteins, and receptors. Under normal conditions an appropriate balance exists in the lung between HLE and endogenous inhibitors, which scavenge the released enzyme before it exerts deleterious effects in the lung. Emphysema is thought to result from an imbalance in the lung between HLE and endogenous inhibitor (elevated elastase or insufficient inhibitor) that leads to the destruction of alveoli. We have identified WIN 64733 (2) and WIN 63759 (3) as potent (Ki* = 14 and 13 pM, respectively), selective, mechanism-based inhibitors of HLE which are orally bioavailable in the dog (absolute bioavailability 46% and 21%, respectively). In this series the in vitro stabilities of the inhibitors in blood, jejunal homogenates, and liver S9 homogenates are useful predictors of oral bioavailability. After being administered orally (30 mg/kg) to dogs, compounds 2 and 3 are found in the lung, being detected in the epithelial lining fluid obtained by bronchoalveolar lavage (Cmax of 2.5 and 0.47 microgram/mL, respectively).

Androgen receptor affinity of 5'-acyl furanosteroids

Syntheses of 5'-acyl furanosteroids are described from the corresponding unsubstituted [3,2-b]furanosteroids using acid anhydrides and acid chlorides in the presence or absence of Lewis acids. New methods have been developed to prepare 5'-acetyl derivatives: reduction of a 5'-trichloroacetyl intermediate either by sodium formaldehyde sulfoxylate or with 10% Pd/C. Most of these 5'-acyl derivatives bind to the rat ventral prostate androgen receptor. However the antiandrogenic activity was diminished when compared with 4,5'-methylsulfonyl furanosteroid. Biological studies revealed that 5'-acyl furanosteroids were either androgens or modest antiandrogens. The electrostatic potential maps of the substructures of 3, 4, and 5'-acetyl syn- and anti-furanosteroids showed striking differences which may explain, to some extent, the lack of significant antiandrogenic activity of 5'-acyl furanosteroids.

Quantification of global and regional renal blood flow with electron beam computed tomography

Alterations in renal blood flow distribution may occur in a variety of pathophysiologic situations; however, quantification of global and regional renal blood flows has been limited because of the lack of reliable, noninvasive techniques. To determine the feasibility of flow measurements with electron-beam computed tomography (EBCT), six anesthetized dogs were scanned by EBCT during basal conditions, after renal vasodilation, and at recovery. Flow (mL/min/cm3 tissue) was calculated from EBCT-derived time-density curves using three different algorithms and compared with simultaneously obtained electromagnetic flow (EMF) probe measurements after indexing to EBCT-derived renal volume. EBCT-determined flow correlated well with EMF measurements regardless of the algorithm used. An algorithm using the area under the time-density curve was concluded to be the most suitable for calculation of renal blood flow; it correlated with EMF as EBCT flow = 44.5 + 1.05 EMF (r = 0.885, SEE = 31.2 mL/min, P < .0001). Consistent overestimation of flow by EBCT resulted probably from retention of contrast media in the renal parenchyma. EMF showed an increase of 20 +/- 10% in renal blood flow after vasodilation. EBCT-derived global, cortical, and medullary flows increased by 33.8 +/- 10.3%, 24.8 +/- 17.8%, and 99.0 +/- 73.8%, respectively. In conclusion, EBCT was found feasible for credible quantitation of renal blood flow in the physiologic range studied.

"Rescue" directional coronary atherectomy after unsuccessful percutaneous transluminal coronary angioplasty

OBJECTIVE

To evaluate the outcome in patients who underwent directional coronary atherectomy after unsuccessful balloon angioplasty.

DESIGN

We conducted a retrospective computerized data bank search of patients in whom unsuccessful balloon angioplasty and subsequent "rescue" coronary atherectomy had been performed at the Mayo Clinic between Nov. 1, 1988, and May 1, 1993.

MATERIAL AND METHODS

Among the 336 patients who underwent directional coronary atherectomy during the study period, in 16 the procedure was a rescue attempt. The mean age of these 16 study patients was 67 years. The following vessels were treated: left anterior descending coronary artery, six patients; right coronary artery, six; circumflex artery, two; and saphenous vein graft, two. Coronary angioplasty had failed because of dissection in eight patients, elastic recoil without evident dissection in seven, and recurrent thrombus without evident dissection in one.

RESULTS

After coronary atherectomy, the mean stenosis was 41% (in comparison with 90% before coronary angioplasty and 71% after coronary angioplasty). Both angiographic success (20% or more decrease in stenosis after tissue removal and a final stenosis of less than 50%) and clinical success (angiographic success without in-hospital Q-wave myocardial infarction, bypass operation, or death) were achieved in 10 patients. Adventitia was obtained in two patients, both of whom underwent atherectomy for elastic recoil. In six patients, a stenosis of more than 50% remained after atherectomy; one patient suffered a Q-wave myocardial infarction, and one underwent emergent coronary artery bypass grafting. No deaths occurred in the study group. During follow-up (mean, 22 +/- 19 months), one patient suffered a non-Q-wave myocardial infarction, and two others underwent elective coronary artery bypass grafting. Eleven patients were asymptomatic at last contact. Repeated angiography, done in five patients a mean of 3.4 +/- 3.1 months after the procedure, showed restenosis in three.

CONCLUSION

Rescue directional coronary atherectomy seems to be safe and effective in achieving angiographic and clinical successes in carefully selected patients after unsuccessful coronary angioplasty.

Immediate and long-term outcome after directional coronary atherectomy: analysis of gender differences

OBJECTIVE

To compare the short-term and long-term outcomes of directional coronary atherectomy in women and men.

DESIGN

We retrospectively analyzed 291 consecutive directional atherectomy procedures performed in 61 women and 230 men at the Mayo Clinic between October 1988 and November 1992.

MATERIAL AND METHODS

The baseline clinical and angiographic characteristics, including extent of coronary artery disease and left ventricular ejection fraction, were compared for the male and female patients, and the short-term and long-term complications associated with atherectomy were summarized on the basis of gender.

RESULTS

At baseline, women were older than men (67 +/- 12 versus 61 +/- 11 years; P = 0.001), and more women than men had class III or IV angina (90% versus 64%; P < 0.001); slightly more women than men had rest pain (64% versus 52%). Overall clinical success (improvement in luminal diameter of 40% or more and no death, Q-wave myocardial infarction, or emergency coronary bypass operation) was achieved in 89% of women and 95% of men (P = 0.054). In-hospital mortality was similar in women and men (1.6% and 1.7%, respectively), but acute myocardial infarction occurred more frequently in women than in men (4.9% versus 0.4%; P = 0.03). Significant peripheral vascular complications occurred in 6.6% of women versus 0.9% of men (P = 0.02). During long-term follow-up (mean, 2.9 years), survival and freedom from recurrent angina were similar among women and men.

CONCLUSION

Directional coronary atherectomy is associated with slightly lower success and a higher frequency of myocardial infarction among women than among men. The higher postprocedural rate of myocardial infarction among women may reflect their worse clinical status at time of initial assessment. Despite these observations, women and men seem to have comparable survival and freedom from recurrence of angina during extended follow-up.

Coronary angioplasty in acute myocardial infarction: primary, immediate adjunctive, rescue, or deferred adjunctive approach?

OBJECTIVE

To address the current clinical applications, outcomes, and limitations of coronary angioplasty in the setting of acute myocardial infarction.

DESIGN

We review the results of several large trials in which various strategies of thrombolysis and primary, immediate adjunctive, rescue, or deferred adjunctive coronary angioplasty were used in patients with acute myocardial infarction.

MATERIAL AND METHODS

Four strategies for the utilization of angioplasty in myocardial infarction have been developed and are based on the timing and concurrent use of thrombolytic therapy.

RESULTS

Primary coronary angioplasty without prior thrombolytic therapy is as effective as thrombolytic therapy for salvaging myocardium. Results of a meta-analysis of recent trials suggest potential benefits of increased survival and decreased reinfarction in comparison with the results of thrombolysis in recent trials. Immediate adjunctive angioplasty after thrombolytic therapy has been tested in three large, randomized trials. The results suggest that this strategy is associated with increased risks without benefits of increased survival or improved left ventricular function. Rescue angioplasty may be helpful after failed thrombolytic therapy. Ongoing randomized trials might further clarify the benefits of rescue angioplasty. Because of the inherent difficulty in the noninvasive identification of patients with persistent reocclusion, diagnostic coronary angiography early after thrombolytic therapy may be necessary. Deferred adjunctive angioplasty during the weeks after infarction to prevent recurrent ischemia was not shown to decrease mortality or reinfarction in two large trials.

CONCLUSION

Primary coronary angioplasty is the treatment of choice for patients with contraindications to thrombolytic therapy. Certain high-risk subgroups may also benefit from primary angioplasty.

Effects of acute changes in canine LV-chamber volume and shape on accuracy of impedance catheter estimates of LV-chamber volume

The accuracy with which a multiple-electrode impedance catheter (IC) tracks instantaneous global, in-situ left ventricular (LV) volumes was tested in 13 anesthetized dogs scanned in the Dynamic Spatial Reconstructor (DSR), a fast volumetric computed tomographic (CT) scanner. All dogs were scanned during control conditions and during an acute hemodynamic intervention. Hypertonic saline calibrations were performed for the IC prior to each DSR scan. In six of the dogs the IC-derived LV end-diastolic volume (Y) correlated with the DSR-derived global LV end-diastolic volume (X) as follows: end-diastolic volume, Y = 1.01X - 9.9, r = 0.812. The IC-derived LV end-diastolic volume, under control conditions, correlated with the DSR-derived truncated (i.e., that region of the LV chamber between the proximal and distal electrodes of the IC catheter) LV end-diastolic volume, Y = 1.00X + 17.4, r = 0.803. Under reduced preload the relation was Y = 1.3X - 15.26, r = 0.911. The segmental volume (between adjacent sensing electrodes on the IC) at the basal portion of the LV correlated poorly (Y = 1.88X + 3.3, r = 0.459 etc.), but correlated better at mid- and more apical LV levels (Y = 0.97X + 2.7, r = 0.762). Correlations between segmental stroke volumes were similar at basal (Y = 1.31X + 1.60, r = 0.815) and mid- and more apical levels (Y = 1.42X + 0.11, r = 0.763). Stroke volume during acute ischemia (two dogs) was Y = 1.33X - 1.41, r = 0.717; during acutely decreased preload (four dogs) it was Y = 1.24X - 2.88, r = 0.572). Thus, the IC tracks the changes in LV-chamber volume throughout a cardiac cycle quite well under a variety of conditions, but accuracy deteriorates as the shape of the LV chamber changes in response to changes in hemodynamic loading or local myocardial ischemia.