Targeted vascular drug delivery. A new day for an old way

Local drug delivery for the treatment of vascular disease has been studied for many years. In coronary artery disease, drug eluting stents are routinely deployed. However, with concerns regarding late thrombosis, and clinical applications where stenting is not desirable, such as peripheral vascular disease, a new direction to "leave nothing behind" has emerged. In Europe, paclitaxel-coated balloons have shown promise in reducing restenosis in both peripheral and coronary applications. However, a number of technical, economic and regulatory limitations of the current devices have been identified. Local or targeted fluid delivery of drugs may offer a relatively simple solution.

Rotational atherectomy or balloon angioplasty in the treatment of intra-stent restenosis: BARASTER multicenter registry

The BARASTER registry was formed to evaluate the initial success and long-term results of rotational atherectomy in the management of in-stent restenosis. Rotational atherectomy was used in 197 cases of in-stent restenosis: 46 with stand-alone rotational atherectomy or at most 1 atmosphere of balloon inflation (Rota strategy), and 151 with rotational atherectomy and adjunctive balloon angioplasty <1 atmosphere (Combination strategy). These were compared with 107 episodes of in-stent restenosis treated with balloon angioplasty alone. In this observational study, the use of Combination therapy was associated with a slightly higher initial success rate (95% vs. 87% with the Rota strategy and 89% with Balloons, P = 0.08). There was a reduction in one year clinical outcomes (death, myocardial infarction or target lesion revascularization) in the combination group (38% vs. 60% with Rota and 52% with balloons, P = 0.02). These data support a benefit of the strategy of debulking with rotational atherectomy followed by adjunctive balloon angioplasty, in the management of in-stent restenosis.

The PARAGON stent study: a randomized trial of a new martensitic nitinol stent versus the Palmaz-Schatz stent for treatment of complex native coronary arterial lesions

A new martensitic nitinol stent with improved flexibility and radiopacity was tested to evaluate whether these differences improve initial or long-term outcome. Patients who underwent percutaneous revascularization of a discrete native coronary lesion were randomly assigned to the new stent (PARAGON, n = 349) or to the first-generation Palmaz-Schatz (PS) stent (n = 339). The primary end point was target vessel failure at 6 months (a composite of cardiac or noncardiac death, any infarction in the distribution of the treated vessel, or clinically indicated target vessel revascularization). Secondary end points were, among others, device and procedural success and angiographic restenosis. Mean age was 62 years; diabetes was present in 21% of patients, prior bypass surgery in 6%, and recent infarction in 22% (p = NS for comparison between the 2 randomized arms). The PARAGON stent group had smaller reference vessels (2.97 vs 3.05 mm, p = 0.05), more prior restenosis (8.0% vs 4.5%, p = 0.07), and a longer average stent length (21.3 vs 19.4 mm, p < 0.05). Device success was significantly higher in the PARAGON arm (99.1% vs 94.3%, p < 0.05). Death and infarction at 6-month follow-up were infrequent in both groups. There was no significant difference in death (2.0% vs 1.2%, p = 0.546), but a higher rate of infarction for the PARAGON cohort (9.2% vs 4.7%, p = 0.025). Although target vessel failure (20.3% vs 12.4%, p = 0.005) and target lesion revascularization (12.0% vs 5.9%, p = 0.005) were higher in the PARAGON group, there was no significant difference in 6-month follow-up in in-stent minimal lumen diameter or in the rate of binary angiographic restenosis. Both PARAGON and PS stents are safe and associated with infrequent adverse events. The PARAGON stent can be delivered more frequently than the first-generation PS stent. Although there was no significant difference in in-stent minimal lumen diameter or the frequency of angiographic restenosis, clinical restenosis was more frequent in the PARAGON group.

Randomized trial of contrast media utilization in high-risk PTCA: the COURT trial

BACKGROUND

Previous in vitro and in vivo studies have suggested an association between thrombus-related events and type of contrast media. Low osmolar contrast agents appear to improve the safety of diagnostic and coronary artery interventional procedures. However, no data are available on PTCA outcomes with an isosmolar contrast agent.

METHODS AND RESULTS

A multicenter prospective randomized double-blind trial was performed in 856 high-risk patients undergoing coronary artery intervention. The objective was to compare the isosmolar nonionic dimer iodixanol (n=405) with the low osmolar ionic agent ioxaglate (n=410). A composite variable of in-hospital major adverse clinical events (MACE) was the primary end point. A secondary objective was to evaluate major angiographic and procedural events during and after PTCA. The composite in-hospital primary end point was less frequent in those receiving iodixanol compared with those receiving ioxaglate (5.4% versus 9.5%, respectively; P=0.027). Core laboratory defined angiographic success was more frequent in patients receiving iodixanol (92.2% versus 85. 9% for ioxaglate, P=0.004). There was a trend toward lower total clinical events at 30 days in patients randomized to iodixanol (9.1% versus 13.2% for ioxaglate, P=0.07). Multivariate predictors of in-hospital MACE were use of ioxaglate (P=0.01) and treatment of a de novo lesion (P=0.03).

CONCLUSIONS

In this contemporary prospective multicenter trial of PTCA in the setting of acute coronary syndromes, there was a low incidence of in-hospital clinical events for both treatment groups. The cohort receiving the nonionic dimer iodixanol experienced a 45% reduction in in-hospital MACE when compared with the cohort receiving ioxaglate.

Quantitative angiography of coronary artery dimensions 24 hours after rotational atherectomy

Rotational atherectomy results in platelet activation and heat generation, which may impact artery size immediately after treatment. In addition, arteries treated with balloon angioplasty may exhibit recoil within 24 hours. In this study, arteries treated with rotational atherectomy, with and without adjunctive balloon angioplasty, were analyzed by quantitative coronary angiography to determine the effect of rotational atherectomy on the dynamic behavior of the arterial wall within 24 hours after the procedure. Quantitative coronary angiography was performed at a core laboratory. Coronary angiogram acquisitions were preceded by intracoronary nitroglycerin injections and were repeated using identical angles of projection. Proximal and distal reference vessel diameters were 2.55 +/- 0.60 and 2.28 +/- 0.51 mm, respectively, and did not change from pre- to postprocedure. Both were larger the following day increasing to 2.72 +/- 0.65 and 2.52 +/- 0.52 mm, respectively, (p <0.001). Minimum luminal diameter (MLD) increased from 0.70 +/- 0.28 mm before to 1.49 +/- 0.34 mm after the procedure and to 1.72 +/- 0.37 mm at 24-hour follow-up (p <0.001). Subset analysis of patients treated with rotational atherectomy alone or rotational atherectomy with adjunctive balloon angioplasty revealed that the increase in luminal diameters occurred in both subsets. Patients treated with adjunctive angioplasty had a smaller initial MLD, a larger postprocedure MLD, and no difference in MLD at 24-hour follow-up compared with stand-alone rotational atherectomy. Subset analysis of 100 patients who had 6-month follow-up angiography revealed that both a calculated acute gain and chronic late loss, based on a 24-hour film, differed significantly from values using a film acquired immediately after the procedure. However, the slope of the linear regression between acute gain and chronic late loss did not differ. Coronary arteries treated with rotational atherectomy with or without adjunctive balloon angioplasty increase significantly in size during the first 24 hours after the procedure. This phenomenon has implications for the calculation of absolute gain and chronic late loss, but not for the linear relation between the 2 quantitative outcomes.

Successful coronary stenting in a 4-year-old child

This report describes a 4-yr-old with critical coronary artery stenosis acquired after surgery for congenital heart disease. The patient was treated successfully with coronary stenting after unsuccessful angioplasty.

Acute and long-term outcome after Palmaz-Schatz stenting: analysis from the New Approaches to Coronary Intervention (NACI) registry

The randomized Stent Restenosis Study (STRESS) and Belgium Netherlands Stent (Benestent) trials established that elective use of Palmaz-Schatz stents (PSSs) in native coronary arteries with de novo lesions is associated with increased procedural success and reduced restenosis. However there are other clinical indications for which stents are commonly used (unplanned use, vein grafts, restenosis lesions) that are not addressed in these studies. From 1990-1992, 688 lesions in 628 patients were treated with PSSs in the New Approaches to Coronary Intervention (NACI) registry. Angiographic core laboratory readings were available for 543 patients (595 lesions, of which 106 were stented for unplanned indications, 239 were in saphenous vein bypass grafts, and 296 were previously treated). The cohort of patients in whom stents were placed for unplanned indications had more women, current smokers, and had a higher incidence of recent myocardial infarction (MI). Patients who underwent stenting of saphenous vein grafts were older, had a higher incidence of diabetes mellitus, unstable angina, prior MI, and congestive heart failure. Lesion success was similar in all cohorts (98%), but procedural success was significantly higher for planned stenting (96% vs 87%; p < 0.01). Predictors of adverse events in-hospital were presence of a significant left main stenosis and stenting for unplanned indication. The incidence of target lesion revascularization by 30 days was significantly higher for patients undergoing unplanned stenting due to a higher risk for stent thrombosis. Recent MI, stenting in native lesion, and small postprocedural minimum lumen diameter independently predicted target lesion revascularization at 30 days. Independent predictors of death, Q-wave myocardial infarction, or target lesion revascularization at 1 year included severe concomitant disease, high risk for surgery, left main disease, stenting in the left main coronary artery, and low postprocedure minimum lumen diameter.

High-speed rotational atherectomy of human coronary stenoses: acute and one-year outcomes from the New Approaches to Coronary Intervention (NACI) registry

High-speed rotational atherectomy (RA) is a new percutaneous procedure for treatment of coronary stenoses that operates by the unique mechanism of plaque abrasion. This article reports acute (in-hospital) outcomes and 1-year follow-up in a large cohort of patients treated with this device by NACI investigators. A total of 525 patients with 670 lesions treated with RA form the substrate of this report. Patients tended to be older (mean age 64.8 years) than those in previously reported series of percutaneous transluminal coronary angioplasty (PTCA), with more extensive disease and more complex lesions. Calcification was present in 54% of lesions, and eccentricity in 41%. Balloon angioplasty postdilation was performed after RA in 88% of cases. Angiographic and procedural success (angiographic success without death, Q-wave myocardial infarction [MI] or emergency coronary artery bypass graft [CABG] surgery) rates were 89% and 88%, respectively. Acute in-hospital events included 4 deaths (1%) and 1 emergency CABG surgery (0.4%). MI occurred in 6% of patients, consisting predominantly of non-Q-wave MI (5%). After RA, angiographic complications included coronary dissection (12%), abrupt closure (5%), side branch occlusion (3%), and distal embolization (3%). Most of these were resolved after postdilation except for coronary dissection, which was present in 15% of lesions treated. Mean length of stay was 3 days. At 1-year follow-up, 27% of patients required target lesion revascularization and 30% had experienced death, Q-wave MI, or target lesion revascularization. Preprocedural characteristics that independently predicted 1-year death, Q-wave MI, or target lesion revascularization were male gender, high risk for surgery, target lesions that were proximal to or in bifurcations, eccentric, long, or highly stenosed. RA, even when applied to lesions of traditionally unfavorable morphology, appears to provide reasonable procedural and angiographic success rates. Restenosis and progression of disease contribute to subsequent clinical and procedural events.

Comparison of early and recent results with rotational atherectomy

OBJECTIVES

We compared an early registry of rotational atherectomy with a recent registry to examine the evolution of patient profiles, lesion characteristics and procedural outcomes for patients treated with rotational atherectomy.

BACKGROUND

With increased experience, the selection of patients and lesions treated with a device matures. This study documents the changes in the application of rotational atherectomy.

METHODS

The patient characteristics and procedural outcomes from two multicenter patient registries-Registry I: 2,953 procedures, 3,717 lesions from 1988 to 1993; and Registry II: 200 procedures, 268 lesions from 1994-were analyzed and compared.

RESULTS

There was an increase in the average age of the patients (63 vs. 65 years, p < 0.02) and the proportion of patients with unstable angina (42.9% vs. 56.5%, p < 0.01) or previous coronary artery bypass graft surgery (18.8% vs. 24.5%, p < 0.05) in Registry II. Registry II included fewer left anterior descending coronary lesions (46.5% vs. 32.8%, p < 0.01), more type B and C lesions (83.1% vs. 91.8%, p < 0.01), more eccentric lesions (69.0% vs. 79.5%, p < 0.01) and more calcified lesions (50.3% vs. 69.4%, p < 0.01). Complications, including urgent bypass surgery, Q and non-Q wave myocardial infarction, dissection, acute occlusion and perforation, were similar in the two groups. However, mortality increased from 1.0% to 3.0% (p < 0.05) in Registry II.

CONCLUSIONS

Comparison of recent and early patients treated with rotational atherectomy revealed an increase in the complexity of patients and lesions. Although the rate of death was increased, the overall rate of major complications was not significantly changed (4.7% vs. 6.0%, p = NS).

Comparison of patients with either < 70% diameter narrowing or > or = 70% narrowing of the right coronary artery when performing rotational atherectomy on > or = 1 narrowing in the left coronary arteries

This study compares the complication rates of patients undergoing rotational atherectomy of the left coronary system who had either minimal or significant narrowing of the right coronary artery (RCA). A series of 1,872 patients from a multicenter registry who were treated for left coronary artery disease were divided into <70% diameter stenosis (mild) and > or = 70% stenosis (severe) of the RCA. The patient demographics, lesion characteristics, and frequency of procedural complications for each group were compared. Of the 1,872 patients undergoing rotational atherectomy of the left coronary system, 86.3% (n = 1,616) had mild RCA disease and 13.7% (n = 256) had severe RCA disease. Comparing the mild and severe groups, death (0.8% vs 3.1%, p <0.005), non-Q-wave myocardial infarction (5.1% vs 8.6%, p <0.04), and bypass surgery (2.7% vs 5.8%, p <0.02) were increased in the severe group. Within the severe group, 7 of 8 deaths were in the 128 patients with total occlusion of the RCA. Multivariate analysis demonstrated that RCA stenosis increases the risk of death by 4.9, bypass surgery by 2.6, and non-Q-wave myocardial infarction by 1.8. Patients treated for left coronary disease who have > or = 70% stenosis of the RCA have increased complications during rotational atherectomy.

Incidence, predictors, and consequences of coronary dissection following high-speed rotational atherectomy

The incidence of dissection following rotational atherectomy was 12.8%. By multivariate analysis tortuosity, primary and non-type B lesions were correlated with an increased incidence of dissection. The procedural success rate was reduced in the presence of dissection (86% vs 96%; p = 0.0001) primarily because patients with dissection required coronary bypass more frequently than those without dissection.

Femoral artery hemostasis using an implantable device (Angio-Seal) after coronary angioplasty

Coronary catheter interventional procedures are associated with risk of access site complications. We report our experience with Angio-Seal, an implantable hemostasis device, when used in the femoral artery after coronary angioplasty procedures. Sixty-eight patients were studied. Their average age was 63 years; 84% of the patients were male. All had 8 French access sheaths and received bolus heparin (mean dose 12,690 U). The arterial sheaths were removed an average of 455 min after the conclusion of the procedure, when the activated clotting time was 220 +/- 94 sec (range 97-503 sec). The hemostasis device was successfully deployed in 63 patients (93%). The average time to achieve complete arterial hemostasis was 4.4 +/- 8.9 min (range 0-45). Immediate, total hemostasis without requiring any form of external pressure was obtained in 37 of these patients (54%). the incidence of complications was as follows: significant bleeding occurred in 9 patients (13%); there were 2 hematomas (3%); there were no vascular or infectious complications. One device embolization occurred when the connecting suture broke and the intravascular anchor was lost; no clinical sequelae resulted, and manual hemostasis was successful. In four other patients, the device did not deploy and was removed entirely, followed by uneventful manual hemostasis. Follow-up for 2 months revealed no late sequelae in any patient, and complete absorption of the device was documented by ultrasound study in all cases. We conclude that this implantable device can achieve arterial hemostasis quickly and safety when used in anticoagulated patients after coronary interventional procedures.

Role of intraaortic balloon pump counterpulsation in high risk coronary rotational atherectomy

OBJECTIVES

This study sought to evaluate the role of intraaortic balloon pump counterpulsation in preventing hemodynamic instability and promoting a successful outcome during percutaneous transluminal coronary rotational atherectomy in high risk patients.

BACKGROUND

The application of rotational atherectomy has widened to include patients with complex lesions and left ventricular dysfunction. Although intraaortic balloon pumping has been successfully used to provide hemodynamic support during balloon angioplasty, its role in high risk rotational atherectomy has not yet been defined.

METHODS

In a retrospective review of 159 consecutive high risk patients who underwent rotational atherectomy, 28 had an intraaortic balloon pump placed electively before the procedure (Group 1) whereas 131 did not (Group 2).

RESULTS

Group 1 was older and more likely to have multivessel disease and left ventricular dysfunction. Augmented diastolic pressure was maintained > 90 mm Hg in all Group 1 patients, and significant procedure-related hypotension was encountered in nine Group 2 patients, requiring an emergency intraaortic balloon pump in five. Procedural success was achieved in all 28 patients in Group 1 and in 118 in Group 2 (p = 0.07). Slow flow occurred in 18% and 17% of Group 1 and 2 patients, respectively. Among patients with slow flow, non-Q wave myocardial infarction occurred only in Group 2 (0% vs. 27%). On multivariate analysis, elective intraaortic balloon pump placement was the only variable to correlate with a successful procedure uncomplicated by hypotension (p < 0.05). Hospital stay and vascular complications were similar in both groups.

CONCLUSIONS

Elective placement of an intraaortic balloon pump before coronary rotational atherectomy in selected high risk patients promotes both procedural hemodynamic stability and a successful outcome.

High speed rotational atherectomy: outcome in calcified and noncalcified coronary artery lesions

OBJECTIVES

This study sought to determine the success and complication rates of high speed rotational coronary atherectomy in calcified and noncalcified lesions.

BACKGROUND

Percutaneous transluminal coronary angioplasty and directional coronary atherectomy of calcified lesions are associated with reduced procedural success and increased complications. Rotational atherectomy using the Rotablator catheter abrades noncompliant plaque and may improve outcome in calcified lesions.

METHODS

Data from the completed Multicenter Rotablator Registry of 2,161 rotational atherectomy procedures in single lesions were analyzed to determine the relative efficacy of rotational atherectomy for 1,078 calcified and 1,083 noncalcified lesions. The power of the study was 0.86 to detect a significant difference in outcome, if the true success rates in the noncalcified and calcified lesions were 96% and 93%, respectively.

RESULTS

Patients with calcified lesions were older (mean [+/- SD] age 66.2 +/- 10.3 vs. 60.5 +/- 11.0 years, p = 0.0001) than those with noncalcified lesions. Calcified lesions were more frequently new (75% vs. 64%, p = 0.0001), angulated (27% vs. 22%, p = 0.02), eccentric (75% vs. 64%, p = 0.0001) and long (32% vs. 27%, > 10 mm in length, p = 0.01). They were also more often complex (57% vs. 46%, p = 0.001) and located in the left anterior descending coronary artery (51% vs. 44%, p = 0.001). Adjunctive coronary angioplasty was used in 82.9% of calcified and 66.9% of noncalcified lesions. Procedural success, defined as < 50% residual stenosis without major complications, was achieved in 94.3% of calcified and 95.2% of noncalcified lesions (p = 0.32). Major complication rates were 4.1% in calcified and 3.1% in noncalcified lesions (p = 0.24). Non-Q wave myocardial infarction was documented in 10.0% of calcified and 7.7% of noncalcified lesions (p = 0.054). Mean postprocedural residual stenosis was 21.6 +/- 13.9% in calcified and 23.3 +/- 15% in noncalcified lesions (p = 0.39).

CONCLUSIONS

In this review of data from a large multicenter registry, the success rate of rotational atherectomy was not reduced by calcification despite the more frequent complex nature of the calcified lesions. The Rotablator catheter is likely to be the device of choice for percutaneous intervention in calcified lesions, but definitive conclusions await the results of randomized trials.

Rapid arterial hemostasis and decreased access site complications after cardiac catheterization and angioplasty: results of a randomized trial of a novel hemostatic device

OBJECTIVES

This study was performed to test the safety and efficacy of a novel bioabsorbable hemostatic puncture closure device deployed through an arterial sheath.

BACKGROUND

Cardiac catheterization procedures are associated with a risk of complications at the arterial access site. Increasing numbers of interventional procedures requiring large sheaths or intense anticoagulation underline the need for secure, rapid methods of obtaining hemostasis at the time of sheath removal.

METHODS

We conducted a randomized, multicenter trial in 435 patients undergoing cardiac catheterization or angioplasty at eight participating centers. In 218 patients, hemostasis was achieved using the device (group I); 217 patients were assigned to the manual pressure control group (group II).

RESULTS

There were no significant differences in baseline characteristics. Time to hemostasis was considerably shorter in group I (2.5 +/- 15.2 vs. 15.3 +/- 11.7 min [mean +/- SD], p < 0.0001). The deployment success rate for the device was 96%, and 76% of group I patients experienced immediate (within 1 min) hemostasis. Complication rates were lower in group I for bleeding, hematoma and occurrence of any complication. There was no difference in the small incidence of pseudoaneurysm formation. There was no change in either group in the ankle/brachial systolic blood pressure index. Ultrasound follow-up studies 60 days after device deployment revealed complete absorption of the device in all cases. Subgroup analysis revealed particular benefit in patients undergoing interventional procedures. The administration of heparin was associated with a significantly higher complication rate in the manual pressure control group, whereas heparin had no effect on hemostasis time or complication rates in the device group.

CONCLUSIONS

This sheath-deployed, bioabsorbable device provides a safe and effective means of obtaining rapid arterial hemostasis after cardiac catheterization procedures. It appears to be particularly useful in those patients most at risk for access site complications.

Rotational ablation. The Rotablator catheter

High-speed rotational ablation addresses specific limitations inherent in conventional methods of percutaneous revascularization. The Rotablator system represents an alternative mechanism to achieve restoration of luminal dimensions by removing atherosclerotic plaque. This article summarizes results, identifies indications, and discusses potential applications of rotational ablation in the treatment of coronary artery disease.

Rotational atherectomy multicenter registry: acute results, complications and 6-month angiographic follow-up in 709 patients

OBJECTIVES

The purpose of this study was to describe data collected for an industry-sponsored multicenter registry of rotational atherectomy.

BACKGROUND

Several new devices are in use or under development for coronary atherectomy. The clinical role for each is in part defined by descriptive registry data.

METHODS

We describe results in 709 consecutive patients undergoing 743 procedures representing 874 lesions. The majority of lesions were in the left anterior descending coronary artery. Lesion morphology was described as eccentric (61.1%), calcified (32%), tortuous (26.6%) and long (24.9%), with previous intervention in 32.7%.

RESULTS

Overall procedural success rate, including lesions treated with rotational atherectomy alone and with balloon angioplasty was 94.7% and did not vary between lesion type, location, characteristics or severity. Previously treated lesions had a significantly higher success rate (97.4%, p = 0.04) than new lesions. Major complications, including death 0.8% (95% confidence interval [CI] 0.3% to 1.7%), Q wave myocardial infarction 0.9% (95% CI 0.4% to 1.9%) and emergent coronary artery bypass surgery 1.7% (95% CI 0.9% to 3.0%), were similar to other reported devices and were associated with length and number of lesions treated. Non-Q wave myocardial infarction occurred in 3.8% of patients and was significantly associated with female gender and history of previous myocardial infarction. Abrupt occlusion occurred in 3.1% of patients and was significantly associated with bifurcated lesions and the use of adjunctive therapy. Angiographic evidence of dissection was seen in 10.5% (95% CI 8.3% to 12.7%) of patients and was significantly associated with more complex lesions, such as eccentric, long, calcified and American College of Cardiology/American Heart Association type C lesions. Overall restenosis rate was 37.7%, determined with 6-month angiography, representing 64% of treated lesions. Higher restenosis rates were associated only with poorer initial treatment outcome, diabetes and lower follow-up angiographic rate per reporting center.

CONCLUSIONS

Rotational atherectomy appears to be a safe method of treatment with a high success rate in a broad spectrum of lesion types, with restenosis rates similar to other techniques. Further conclusions will require randomized trials.

Relation of clinical presentation, stenosis morphology, and operator technique to the procedural results of rotational atherectomy and rotational atherectomy-facilitated angioplasty

BACKGROUND

Rotational atherectomy using the Rotablator has recently become available to treat coronary stenoses. This study was performed to determine the relation of patient characteristics, stenosis morphology, and operator technique to procedural outcome to gain insight into which patients might be best treated with this device.

METHODS AND RESULTS

Four hundred stenoses from 316 patients randomly selected from the initial Rotablator experience at three major referral institutions were analyzed. Angiographic data were assessed at a central angiographic laboratory using standardized morphological criteria and caliper measurement. Patients were somewhat more elderly than most percutaneous transluminal coronary angioplasty (PTCA)-treated groups (mean age, 64 +/- 11 years), 74% were men, and the lesions treated were often complex (modified American College of Cardiology/American Heart Association lesion type A, 24%; B1, 40%; B2, 30%; and C, 6%). Elective adjunctive PTCA was used for 82% of stenoses treated. Procedural success was achieved in 89.8% of stenoses (93.5% if results with creatine kinase two to three times normal are not counted as failures), and major ischemic complications (death, 0.3%; non-Q-wave myocardial infarction, 5.7%; Q-wave myocardial infarction, 2.2%; or emergency bypass surgery, 0.9%) occurred in 8.9% of patients. Complications were due to epicardial coronary obstruction in 3.8% of patients and to delayed coronary runoff ("slow reflow") in 5.1% of patients. Procedural failure was correlated independently with outflow obstruction (success rate, 64%; odds ratio for failure, 5.4; multivariate P = .002), lesion irregularity (76%; odds ratio, 3.3; P = .003), stenosis bend > or = 60 degrees (73%; odds ratio, 3.7; P = .03), and female sex (84%; odds ratio, 2.4; P = .03). Ischemic complications were correlated independently with lesion length (> or = 50% narrowing) > or = 4 mm (complication rate, 12%; odds ratio, 3.6; multivariate P = .005), right coronary artery stenosis (13%; odds ratio, 2.4; P = .02), stenosis bend > or = 60 degrees (27%; odds ratio, 6.1; P = .03), and female sex (13%; odds ratio, 3.0; P = .04). Slow reflow was correlated with total burring duration (odds ratio, 1.005/s; multivariate P = .001), right coronary artery stenosis (incidence, 17%; odds ratio, 4.5; P = .009), and to a lesser extent with recent myocardial infarction in the treated territory (44%; odds ratio, 4.3; P = .08).

CONCLUSIONS

The procedural outcome of rotational atherectomy is highly correlated with stenosis morphology and location and sex of the patient. After stratification for these parameters, overall outcome with the Rotablator appears to be similar to that with balloon angioplasty and other competing techniques. Short-term outcome with specific subsets of patients may be superior with the Rotablator (calcified stenoses), but this technique might best be avoided in some patients (those with irregular or possibly thrombus-containing stenoses, highly angulated stenoses, and possible right coronary artery stenoses or those associated with impaired distal runoff caused by a recent myocardial infarction or manifest by a fixed thallium defect).

Baseline characteristics and therapeutic goals in the New Approaches to Coronary Intervention (NACI) registry

BACKGROUND

The New Approaches to Coronary Intervention (NACI) voluntary registry was designed to study the use, safety, and efficacy of new percutaneous transluminal interventional devices including directional coronary atherectomy, the transluminal extraction catheter, the rotablator, the Palmaz-Schatz stent, the Gianturco-Roubin stent, the Advanced Interventional Systems (AIS) laser, and the spectranetics laser.

METHODS

To date, more than 3800 consecutive patients treated for the first time with a new device at 41 centers have been entered into the registry. Complete detailed information about the patient, lesions, device characteristics, reasons for device selection, and procedural data, such as adjunctive use of conventional balloon angioplasty (PTCA), was available for the first 2835 patients.

RESULTS

The registry shows that 88% of the 3233 attempts with a new device were intended as a definitive treatment of target lesions, frequently in combination with adjunctive PTCA. The remaining 12% of attempts with a new device were unplanned, prompted by unexpected complications, unsuccessful attempts, or suboptimal results with PTCA. Although there was some overlap in the indications for selecting a given interventional device, the variation from device to device was sufficiently large to caution users against any direct comparison of either safety or efficacy between devices without careful attention to the differences in baseline patient and lesion characteristics, treatment plans, and the circumstances of device use.

CONCLUSION

This report provides the first comprehensive overview of how new interventional devices are currently being used in the treatment of coronary artery lesions at the 41 centers participating in the NACI registry.

Emergent use of balloon-expandable coronary artery stenting for failed percutaneous transluminal coronary angioplasty

BACKGROUND

The balloon-expandable intracoronary stent developed by Palmaz and Schatz is undergoing clinical evaluation for use in unfavorable anatomic situations and in the prevention of restenosis. Because the stent's mechanism of action would suggest effectiveness in salvaging certain percutaneous transluminal coronary angioplasty (PTCA) failures, we retrospectively examined the results of emergency unplanned coronary artery stenting for failed PTCA procedures, including acute occlusion.

METHODS AND RESULTS

The study population consisted of all US patients receiving emergency unplanned stent implantation in a nonrandomized fashion at seven centers over a 2 1/2-year period (n = 56). All available medical records and angiograms were reviewed to determine retrospectively the reason for stenting: Group 1 consisted of 23 patients with a suboptimal angioplasty result; group 2 included patients with evidence of impending vessel closure after PTCA (n = 15); and group 3 were patients with frank acute occlusion after PTCA (n = 18). The immediate and final (30-day) results of stenting were examined with respect to major complications, which included death, need for coronary artery bypass graft surgery, and occurrence of myocardial infarction. Finally, restenosis rates (greater than or equal to 50% stenosis) based on follow-up angiography were calculated. Baseline characteristics of the study population included a mean +/- SD age of 58 +/- 11 years and a large prevalence of angiographic characteristics generally considered unfavorable for PTCA, which include lesion eccentricity (49%), intimal dissection (9%), or angiographically visible thrombus (6%). After conventional balloon angioplasty, there was an increased incidence of intimal dissection (74%) and thrombus formation (38%), and overall stenosis severity was unchanged (75 +/- 12% versus 70 +/- 27%, p = NS). Successful stent deployment was achieved in 55 (98%) of 56 patients with initial success (freedom from death, surgery, and infarction) in 52 (93%) of 56 patients. The success rate at 1 month fell to 71% primarily because of the occurrence of subacute stent thrombosis (16%) and its associated complications. Overall, major complications occurred in 16 (29%) of 56 patients within 30 days. The only predictor of subacute stent thrombosis in multiple stepwise logistic regression analysis was the presence of angiographically visible thrombus after stenting (p = 0.03). Angiographic restenosis was documented in eight (23%) of 35 eligible patients.

CONCLUSIONS

Emergency stenting may be a useful and effective treatment for failed angioplasty. High initial success rates (greater than 90%) can be achieved, but subsequent complications, often related to subacute thrombosis, occur in a substantial portion of patients. Patients who receive stents on an emergency basis, particularly those with previous acute occlusion, should be considered to be at greater than usual risk for complications and receive more careful anticoagulation and follow-up.

Chronic major-vessel thromboembolic pulmonary artery obstruction: appearance at angiography

The pulmonary angiograms of 250 patients evaluated for chronic thromboembolic pulmonary hypertension were reviewed. Pulmonary thromboendarterectomy was performed in each of these individuals, and the surgical findings were correlated with abnormal angiographic patterns. The pulmonary angiographic findings suggestive of chronic thromboembolic disease included "pouching" defects, webs or bands, intimal irregularities, abrupt vascular narrowing, and complete vascular obstruction. Pouching is reported by the authors to be a previously undescribed angiographic feature of this disease. Carefully obtained and properly interpreted pulmonary angiograms are necessary to confirm the diagnosis of operable chronic thromboembolic disease. Differential diagnostic possibilities should be considered prior to a decision to perform surgical correction.

Emergent saphenous vein graft stenting for acute occlusion during percutaneous transluminal coronary angioplasty

This report describes the initial use in the United States of emergency intravascular stenting for the treatment of acute coronary occlusion complicating elective saphenous vein graft angioplasty. This case adds further support to the role of the balloon expandable stent as an effective "bail out" device for failed angioplasty.

Intracoronary urokinase for intracoronary thrombus accumulation complicating percutaneous transluminal coronary angioplasty in acute ischemic syndromes

Intracoronary urokinase was used to treat flow-limiting intracoronary thrombus accumulation that complicated successful percutaneous transluminal coronary angioplasty (PTCA) during acute ischemic syndromes in 48 patients who were followed up through the acute phase of their illness. The study group comprised 10 patients with unstable angina pectoris, 18 patients with an evolving acute myocardial infarction, and 20 patients with postinfarction angina. The initial mean percent coronary diameter stenosis for the entire population was 95 +/- 7% and decreased with initial PTCA to 41 +/- 20% (p less than 0.001), with improved corresponding coronary flow by Thrombolysis in Myocardial Infarction trial (TIMI) grade. However, thrombus accumulation then resulted in a significant increase in percent diameter stenosis to 83 +/- 17% (p less than 0.001); a corresponding significant reduction in coronary flow also occurred by TIMI grade. After administration of intracoronary urokinase (mean dose, 141,000 units; range, 100,000-250,000 units during an average period of 34 minutes), with additional PTCA, mean percent diameter stenosis significantly decreased to 34 +/- 17% (p less than 0.001); a correspondingly significant improvement in mean coronary flow by TIMI grade occurred to 2.9 +/- 0.2. Overall, the angiographic success rate was 90%. There were no ischemic events requiring repeat PTCA and no procedure-related myocardial infarctions or deaths before hospital discharge. One patient was referred for urgent coronary artery bypass graft surgery after a successful PTCA. Plasma fibrinogen levels were obtained in 15 patients, and in no patient was the level below normal for our laboratory.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanisms of hypoxemia in chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is characterized by widespread central obstruction of the pulmonary arteries with organized thrombus and thereby differs substantially from other forms of pulmonary hypertension. We studied 25 patients using the multiple inert gas elimination technique to identify and quantitate the physiologic mechanisms of hypoxemia in this disorder. All patients had chronic obstruction of the central pulmonary arteries, which was demonstrated angiographically and later surgically confirmed. All patients but one were hypoxemic (PaO2 = 65 +/- 11 mm Hg, PaCO2 = 32 +/- 4 mm Hg, AaPO2 = 45 +/- 14 mm Hg), and all patients had pulmonary hypertension (mean Ppa = 45 +/- 11 mm Hg) with an elevated pulmonary vascular resistance (mean PVR = 1,000 +/- 791 dyne/s/cm5, normal less than 300). The cardiac index was reduced (1.7 +/- 0.6 L/min/m2), as was the P-vO2 (31 +/- 5 mm Hg). Inert gas studies revealed widened unimodal Va/Q distributions in 20 of 25 subjects, with a log standard deviation of 1.01 +/- 0.32 (upper limit of normal, 0.6; ages 20 to 40), shunt = 0.03 +/- 0.05 of cardiac output, and dead space of 3.4 +/- 1.1 ml/kg (upper limit of normal, 2.9). The VD/VT ratio was 0.51 +/- 0.10. No low (VA/Q less than 0.1) or high (VA/Q greater than 10.0) regions were present, and no evidence for diffusion limitation of O2 transfer at rest was found. The low cardiac output and resulting low P-VO2 were responsible for approximately 33% of the increased AaPO2. The magnitude of the VA/Q abnormality correlated poorly with the PVR, the mean Ppa, or the magnitude of vascular obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary angiography in severe chronic pulmonary hypertension

We have analyzed the safety of doing pulmonary angiography in 67 consecutive patients with moderate-to-severe primary pulmonary hypertension or hypertension secondary to chronic thromboembolic occlusions of the pulmonary arteries. The average (+/- SD) pulmonary arterial systolic and diastolic pressures were 74 +/- 19 and 34 +/- 10 mm Hg, respectively. Fourteen patients had a right ventricular end-diastolic pressure of 20 mm Hg or more. Selective left and right main pulmonary artery injections were done using ionic contrast agents in 56 patients and nonionic contrast agents in 11. No major rhythm disturbances or systemic hypotension requiring therapy occurred, and there were no deaths. Thrombotic occlusions of the pulmonary arteries were identified in 52 patients and confirmed in all 42 of those who had a thromboendarterectomy. At autopsy, 3 of the 15 patients who had normal angiograms were found not to have had thrombotic occlusions. We conclude that pulmonary angiography can be done safely despite the presence of severe pulmonary hypertension and right ventricular failure, and that the procedure leads to the identification of chronic, major-vessel thromboembolic pulmonary hypertension that may be alleviated by thromboendarterectomy.

Thromboembolic complications of percutaneous transluminal coronary angioplasty for myocardial infarction

To determine the incidence of thromboembolic complications of percutaneous transluminal coronary angioplasty (PTCA) in the setting of recent and acute myocardial infarction, the clinical sequelae and coronary angiographic findings were examined in a series of 13 patients who underwent PTCA either as acute intervention during the infarction or as treatment for recurrent myocardial ischemia that occurred soon after the initial completed infarction. In all cases, the angiographic appearance in the infarct-related artery was that of thrombus in the setting of total or subtotal occlusion. Balloon dilatation without antecedent thrombolytic therapy, was performed in 14 arteries and was successful in establishing reperfusion with reduction of the degree of intraluminal narrowing to less than 50% in all cases. Residual thrombus at the site of inflation was noted in two cases (15%), and embolization was noted in four cases (29%), for an incidence of complication of 44%. In five of six instances in which either residual thrombus or embolization were noted, the initial infarction had occurred greater than 24 h before. In only one of seven cases in which PTCA was used as acute intervention during infarction of less than 4 h duration was the presence of residual thrombus noted after PTCA. Therefore, these findings suggest that thromboembolic complications after PTCA in the setting of recent or acute myocardial infarction are uncommon when the syndrome is less than 4 h duration; however, complications are relatively frequent when infarction has occurred greater than 24 h before. PTCA as a primary intervention in this latter setting should be approached cautiously.

Four-incision radial keratotomy for low to moderate myopia

The first 112 consecutive eyes (75 patients) to undergo four-incision radial keratotomy (RK) performed by four surgeons were evaluated retrospectively. The preoperative myopia (spherical equivalent) ranged from -1.12 to -7.00 D (95% between -1.12 and -4.25 D). The preoperative uncorrected visual acuity was 20/100 or worse in 95% of the eyes. A six-month follow-up was achieved in 95% of the eyes and 45% were followed over one year. Following four incision RK, 79% of the eyes achieved 20/40 or better vision and 82% were corrected to within 1 D of emmetropia. Following repeat RK in 15 eyes (13%), 82% had uncorrected visual acuity of 20/40 or better, and 90% were corrected to within 1 D of emmetropia. Only 3.5% of the eyes were overcorrected by more than 1 D and only one eye had induced astigmatism greater than 1 D. For eyes with preoperative myopia up to -4.25 D over 90% achieved uncorrected visual acuity of 20/40 or better and were within 1 D of emmetropia following primary four incision RK and a second four incisions in 13 eyes (12%). Only 3.5% of the eyes in this group were overcorrected by more than 1 D. There were no serious complications.

Angioplasty at coronary bifurcations: single-guide, two-wire technique

A technique is described for angioplasty at coronary bifurcations. This simple approach utilizes a single guiding catheter, an exchange wire, and a conventional dilatation catheter and guidewire. With this "protective" guidewire technique, side branches at risk from occlusion during dilatation of a primary coronary segment can be protected and dilated secondarily; continual access to the threatened side branch is maintained with a "standby" exchange wire in the branch vessel.

Reduction of ischemic depolarization by the calcium channel blocker diltiazem. Correlation with improvement of ventricular conduction and early arrhythmias in the dog

Calcium channel blockers suppress early ischemic arrhythmias, possibly by diminishing intracellular calcium overload and its effect on the ventricular action potential. To explore this, we compared the effects of diltiazem on ischemic "injury" potentials and ventricular fibrillation during serial coronary artery occlusions in dogs. Injury potentials and ventricular fibrillation were elicited every 15-25 minutes by simultaneous occlusion of the left anterior descending and circumflex arteries during rapid atrial pacing. DC epicardial electrograms were recorded differentially between the ischemic region and a small nonischemic region supplied by a proximal branch of the left anterior descending artery. Injury potentials developed with a uniform time course during five control occlusions, but were reduced by diltiazem infusion (0.5 mg/kg over 25 minutes) in each of eight dogs. The mean diastolic injury potential (T-Q depression) at 150 seconds of ischemia was 9.1 +/- 2.7 mV before diltiazem and 6.1 +/- 1.6 mV afterward (P less than 0.001). Diltiazem increased the mean time between coronary occlusion and ventricular fibrillation from 186 to 366 seconds (P less than 10(-5), but did not change the magnitude of the diastolic injury potential at onset of ventricular fibrillation. Diltiazem also delayed ischemia-induced conduction impairment to the same extent that it delayed injury potential development. In five dogs, the effect of diltiazem on regional blood flow near the epicardial electrodes was measured by infusion of radionuclide-labeled microspheres. Coronary occlusion reduced flow to the ischemic zone from 0.86 to 0.05 ml/min per g (P = 0.001). Diltiazem increased preocclusion flow by 11% (P = 0.03), but did not significantly alter flow during occlusion. Hemodynamic measurements show that diltiazem did not diminish cardiac work. Diltiazem therefore produced a flow-independent reduction of cellular depolarization during ischemia, which may be due to relief of calcium overload, and which may explain the antifibrillatory effect.

Calcium overload, "injury" current, and early ischaemic cardiac arrhythmias--a direct connection

Intracellular calcium ions induce a depolarising inward current by reacting with specific sites on the inner surface of cardiac muscle cell membranes. Since intracellular calcium overload invariably occurs with myocardial ischaemia, it may be that the early electrophysiological manifestations of ischaemia, including cellular depolarisation, diastolic current flow, and early ischaemic arrhythmias, are directly mediated by calcium. A simple explanation for the effects of many drugs upon the electrical behaviour of ischaemic myocardium is proposed.

CT and angiographic correlates: surgical image of renal mass lesions

Twenty-three consecutive patients with surgically proved renal mass lesions were examined preoperatively by means of computerized tomography (CT) and renal angiography. Histopathology of the 23 renal masses included the following: hypernephroma (17), transitional cell carcinoma (3), oncocytoma (2), benign cyst (1). Computed tomography was correct in the preoperative diagnosis of 21 of 23 masses (91 per cent); angiographic diagnosis was correct in 18 of 23 consecutive masses (78 per cent). Correlation of the findings on CT and angiography resulted in correct diagnosis in 22 of the 23 lesions (96 per cent). Independently, CT and angiography each contribute essential information for diagnosis and preoperative planning. CT discloses anatomic detail, tissue consistency, organ system relationships, and relatively precise estimates of tumor bulk. Angiography remains a necessary complement providing a surgical image of tumor vascularity and vessel origins.

Enterovesical fistulas in Crohn disease

Fistulous communication between the intestinal tract and the bladder is uncommon in Crohn disease. Only 2% of patients afflicted with this disease present with bladder symptoms. Five patients with a mean age of thirty years presented with a prolonged history of bowel disease but a short history of urinary symptoms. Only three patients presented with pneumaturia and fecaluria. None of the fistulas could be demonstrated radiographically. Cystoscopy disclosed the fistulous site as well as acute and chronic inflammation of the bladder. Small-bowel resection with excision of the fistula, partial bladder resection, and diverting ileostomy were performed as a first stage. Ileostomy closure was done two to four weeks later.

Reduction and subsequent binding of ruthenium ions catalyzed by subcellular components

The reduction of Cl(NH3)5Ru(III) and subsequent binding of heterocyclic ligands by the resultant (H2O)(NH3)5Ru(II) ion is shown to be catalyzed by components of rat-liver cells. The presence of air significantly decreases the rate of heterocyclic ligand binding. In the case of microsome and soluble component catalysis, this is probably due to oxidation of the Ru(II) ion prior to complexation. Various inhibitors of electron-transfer proteins were employed in an effort to determine the preferred reducing species. These results lend support to the hypothesis that the antitumor activity of acido ruthenium(III) ammine complexes involves activation by reduction in vivo prior to metal coordination to nucleic acids. Anticancer drugs functioning by this mechanism may be preferentially toxic to or may localize in hypoxic areas of tumors.

Correlation of cytology and cystoscopy

A total of 152 patients had cytology and cystoscopy performed for either initial or recurrent bladder tumors and postoperative control examinations. Positive cytology was found in 97 per cent of patients with pathologically proved bladder tumors. However, 23 per cent of the patients with negative cytology had positive cystoscopic and pathologically proved findings. Without cystoscopic examination a significant number of recurrent tumors may be missed because of a negative cytology.

Congenital total hemihypertrophy and carcinoma of undescended testicle: a case report

The first case of germinal cell tumor of the testis in a patient with congenital total hemihypertrophy is reported. The literature is discussed with emphasis placed on the frequent association of hemihypertrophy with oncogenesis and teratogenesis. We conclude that because of the high incidence of malignancy in the undescended testis prophylactic orchiectomy should be considered in a patient with hemihypertrophy and cryptorchidism.