Percutaneous patent foramen ovale and atrial septal defect closure in adults: Results and device comparison in 100 consecutive implants at a single center

Closure of interatrial septal defects with percutaneous devices is increasingly common. However, the indications for closure and techniques for device implantation are diverse. We reviewed our first 100 consecutive implants to assess and compare the indications, results, complications, and evolution of techniques for percutaneous patent foramen ovale (PFO) and atrial septal defect (ASD) closure. The mean age of patients was 52 years and 70% were female. Paradoxical embolism was the predominant indication (94%) for PFO closure and significant left-to-right shunt was the most frequent indication (89%) for ASD closure. Implantation success was 94% with major complications in 3 patients (2.8%). Transesophageal echocardiography was utilized in the initial 27 procedures and then replaced by intracardiac echocardiography in subsequent ones, with an associated reduction in procedure and physician time. During 6 months of follow-up, 3 patients were readmitted for atrial arrhythmias (2 patients) and an MRI-negative neurologic event (1 patient). Echocardiography at 6 months in 83% of the PFO patients revealed moderate and severe positive contrast studies for right-to-left shunting in one third of patients, with differences between devices and insertion techniques. This single-center experience with percutaneous device closure of PFO and ASD in adults demonstrates excellent results with few complications.

One-year clinical outcomes of protected and unprotected left main coronary artery stenting

AIMS

To evaluate outcomes for left main coronary artery (LMCA) stenting and compare results between protected (left coronary grafted) and unprotected LMCA stenting in the current bare-metal stent era.

METHODS

We reviewed outcomes among 142 consecutive patients who underwent protected or unprotected LMCA stenting since 1997. All-cause mortality, myocardial infarction (MI), target-lesion revascularization (TLR), and the combined major adverse clinical event (MACE) rates at one year were computed.

RESULTS

Ninety-nine patients (70%) underwent protected and 43 patients (30%) underwent unprotected LMCA stenting. In the unprotected group, 86% were considered poor surgical candidates. Survival at one year was 88% for all patients, TLR 20%, and MACE 32%. At one year, survival was reduced in the unprotected group (72% vs. 95%, P<0.001) and MACE was increased in the unprotected patients (49% vs. 25%, P=0.005).

CONCLUSIONS

In the current era, stenting for both protected and unprotected LMCA disease is still associated with high long-term mortality and MACE rates. Stenting for unprotected LMCA disease in a high-risk population should only be considered in the absence of other revascularization options. Further studies are needed to evaluate the role of stenting for unprotected LMCA disease.

Combination therapy with clopidogrel and aspirin after coronary stenting

Combination antiplatelet therapy using aspirin and ticlopidine has been the standard of care for prevention of subacute thrombosis following coronary stent implantation. However, the use of ticlopidine is associated with a significant risk of adverse hematologic side effects. Clopidogrel is an inhibitor of ADP-induced platelet aggregation that has a better safety profile than ticlopidine. We examined the 30-day clinical outcome following coronary stent implantation in 253 consecutive patients treated with clopidogrel and aspirin. Follow-up was achieved in 99% of patients and four adverse events were documented. Two patients had angiographically confirmed subacute stent thrombosis (0.8%), and both of these patients underwent successful repeat angioplasty at the stent site. There were two patient deaths during follow-up (0. 8%). One was sudden within 1 week of stent placement and the other occurred in a patient with multisystem organ failure after an extensive myocardial infarction that antedated the stent procedure, with no clinical evidence for stent thrombosis. The combined frequency of subacute stent thrombosis and death was 1.6%. This is comparable to prior studies using the combination of ticlopidine and aspirin following stenting. Therefore, clopidogrel in combination with aspirin appears to be a safe and effective therapy in the prevention of subacute thrombosis following coronary stent implantation.

Predictors of clinical outcome following percutaneous intervention for in-stent restenosis

Percutaneous intervention for the first episode of in-stent restenosis was performed in 177 patients 5.4 +/- 0.3 months after native coronary stent implantation. Medical records were reviewed and patients contacted 13.3 +/- 1.2 months after in-stent intervention to ascertain the subsequent clinical course. The effects of demographic, procedural, and angiographic variables on clinical outcomes were determined. At 2 years, Kaplan-Meier estimated survival was 93 +/- 3% and freedom from death, myocardial infarction, and a third target artery revascularization (TAR) was 67 +/- 4%. The actuarial frequency of a third TAR was 26 +/- 4% at 1 year. Stratification of outcomes according to timing of in-stent intervention revealed an approximate twofold higher frequency of adverse events among patients with early (</=3 months) in-stent restenosis. Advanced age (p = 0.019), prior coronary bypass (p = 0. 017), and early in-stent intervention (p = 0.006) independently predicted increased mortality at follow-up. Systemic hypertension (p = 0.004), diabetes mellitus (p = 0.044), and early in-stent intervention (p <0.0001) independently predicted a third TAR. These variables (p = 0.007, p = 0.027, and p <0.0001, respectively) also independently predicted a composite end point consisting of death, myocardial infarction, and a third TAR. No angiographic variable predicted outcome after in-stent intervention. Thus, long-term outcome following in-stent intervention was favorable. Early in-stent intervention, advanced age, hypertension, and diabetes predicted adverse outcomes.

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.

American College of Cardiology/ European Society of Cardiology international study of angiographic data compression phase I. The effects of lossy data compression on recognition of diagnostic features in digital coronary angiography

OBJECTIVES

This study intended to determine the effect of varying degrees of lossy Joint Photographic Experts Group (JPEG) compression on detection of coronary angiographic features. Background Compression of digital coronary angiograms facilitates playback of images and decreases cost. There are little data on the effect of compression on the accuracy of coronary angiography.

METHODS

At six centers, 71 angiographers each reviewed a set of 100 angiographic sequences. The 100 sequences were divided into four, 25-sequence subsets. Each subset of 25 was displayed either as original images or at one of three compression ratios (CRs) (6:1, 10:1 or 16:1). The effect of lossy compression on the sensitivity and specificity for detection of diagnostic features was determined. The effect of compression on subjective measures of image quality graded by the angiographers was also examined.

RESULTS

Lossy compression at a ratio of 16:1 decreased the sensitivity for the detection of diagnostic features (76% vs. 80%P=0.004). The largest effect was in the detection of calcification (52% vs. 63% at 16:1 compression vs. original images, P<0.001). Subjective indicators of image quality indicated a reduction in confidence in interpretation at CRs of 10:1 and 16:1.

CONCLUSIONS

With increased ratios of lossy compression, a degradation of digital coronary angiograms occurs that results in decreased diagnostic accuracy. The sensitivity for detection of common diagnostic features was decreased, and subjective assessment of image quality was impaired. Caution is warranted in the interpretation of coronary angiograms that have been subjected to lossy JPEG compression beyond a ratio of 6:1.

American College of Cardiology/European Society of Cardiology International Study of Angiographic Data Compression Phase I: The effect of lossy data compression on recognition of diagnostic features in digital coronary angiography

OBJECTIVES

This study intended to determine the effect of varying degrees of lossy Joint Photographic Experts Group (JPEG) compression on detection of coronary angiographic features.

BACKGROUND

Compression of digital coronary angiograms facilitates playback of images and decreases cost. There are little data on the effect of compression on the accuracy of coronary angiography.

METHODS

At six centers, 71 angiographers each reviewed a set of 100 angiographic sequences. The 100 sequences were divided into four, 25-sequence subsets. Each subset of 25 was displayed either as original images or at one of three compression ratios (CRs) (6:1, 10:1 or 16:1). The effect of lossy compression on the sensitivity and specificity for detection of diagnostic features was determined. The effect of compression on subjective measures of image quality graded by the angiographers was also examined.

RESULTS

Lossy compression at a ratio of 16:1 decreased the sensitivity for the detection of diagnostic features (76% vs. 80% p = 0.004). The largest effect was in the detection of calcification (52% vs. 63% at 16:1 compression vs. original images, p < 0.001). Subjective indicators of image quality indicated a reduction in confidence in interpretation at CRs of 10:1 and 16:1.

CONCLUSIONS

With increased ratios of lossy compression, a degradation of digital coronary angiograms occurs that results in decreased diagnostic accuracy. The sensitivity for detection of common diagnostic features was decreased, and subjective assessment of image quality was impaired. Caution is warranted in the interpretation of coronary angiograms that have been subjected to lossy JPEG compression beyond a ratio of 6:1.

Complications of cardiac angiography using low- or high-osmolality contrast agents in patients with left main coronary stenosis

Recently published guidelines suggest that, in view of cost concerns, low-osmolal contrast should be selectively used in patients at increased risk of experiencing a contrast-related complication during cardiac angiography. The suggested criteria include the presence of left main coronary disease. However, the presence of left main disease is not usually known prior to angiography. Contrast-related complications of cardiac angiography were therefore analyzed in a group of 111 clinically stable patients found to have left main coronary stenosis, to determine if use of low-osmolality contrast had any beneficial effect when compared to standard contrast. Data were gathered prospectively as part of a randomized controlled trial, and the subgroup of patients with left main disease was analyzed retrospectively. Complications were divided into minor, intermediate, and major categories. In the 58 patients who received high-osmolar contrast, there were 4 contrast-related minor reactions, 8 intermediate events requiring treatment, and 1 major adverse event. Among the 53 patients who received low-osmolar contrast, there were no minor reactions, 7 intermediate events requiring treatment, and no major adverse events. The only difference of borderline significance was in the incidence of minor reactions requiring no treatment (P = 0.05). Although small and therefore not definitive, this study suggests that 1) universal use of low-osmolar contrast agents would not be expected to eliminate the risk of contrast-related reactions to cardiac angiography; 2) the well-documented clinical differences between high- and low-osmolar contrast primarily involve mild reactions; and 3) standard high-osmolar contrast is reasonably safe in clinically stable patients with left main coronary stenosis. The results therefore are consistent with the notion that selective use of low-osmolar contrast only in unstable patients is safe and appropriate.

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.

Comparison of outcome after stenting for de novo versus restenotic narrowings in native coronary arteries

Intracoronary stenting of de novo narrowings results in a lower restenosis rate when compared with percutaneous transluminal coronary angioplasty. We sought to determine whether intracoronary stenting for restenotic narrowings is associated with a worse outcome when compared with stenting for de novo narrowings. A total of 114 consecutive patients with 124 narrowings were retrospectively identified. Stents were deployed in 46 de novo (37%) and in 78 restenotic (63%) narrowings. The 2 groups were similar with respect to variables known to affect restenosis. Follow-up angiograms were available in 88% of patients at a mean of 6.3 +/- 3.3 months after stent implantation. At follow-up angiography, a significantly higher restenosis rate in the restenotic group was observed (p = 0.05). Restenosis risk could not be predicted from variables known at the time of stent implantation. However, the presence of angina at the time of follow-up was significantly associated with restenosis (p = 0.01). Kaplan-Meier survival curves for freedom from repeat target-site revascularization demonstrated a significant difference in the need for target-site revascularization between the de novo and restenotic groups over the first-year post-stent implantation (p = 0.01; relative risk = 1.94). Multivariate analysis identified restenosis as the indication for stenting (p <0.01), postprocedure percent stenosis (p = 0.01), and narrowing length (p = 0.01) as independent predictors for repeat target-site revascularization. When compared with de novo narrowings, restenotic narrowings have a worse outcome after stenting. A prospective, randomized trial comparing outcome after percutaneous transluminal coronary angioplasty and stents for restenotic narrowings would be useful.

Three-year clinical follow-up after Palmaz-Schatz stenting

OBJECTIVES

Our goals were to examine late clinical outcome in a cohort of patients who electively received Palmaz-Schatz intracoronary stents, to identify specific predictors of outcome and to determine the time course of the development of ischemic cardiac events after stenting.

BACKGROUND

Short-term results of Palmaz-Schatz intracoronary stenting have been promising, with a reduction in both angiographic restenosis and clinical cardiac events up to 1 year after stenting.

METHODS

We analyzed the clinical outcomes in 65 consecutive patients who underwent stenting at least 3 years before analysis. Demographic, clinical and procedural predictors of survival and event-free survival, defined as freedom from myocardial infarction, stent-site percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery or death, were analyzed at a mean follow-up of 39 +/- 17 months.

RESULTS

Absolute survival and event-free survival at 3 years were 88% and 56%, respectively. Three-year freedom from stent-site revascularization was 66%. Predictors of decreased long-term survival (p < 0.05) included diabetes and a high angina score (Canadian Cardiovascular Society class III/IV) at 6 and 12 months after stenting. Predictors of decreased event-free survival (p < 0.05) included a high angina score at 3, 6 and 12 months after stenting, smaller stent deployment balloon size and greater number of stents implanted. Freedom from adverse events by 6 months after stenting also correlated with long-term event-free survival. Eighty-five percent of stent-site revascularizations occurred within 1 year. During late follow-up (>24 months), no patients had stent-site stenoses requiring revascularization, whereas 11% of patients required revascularization in nonstented coronary segments.

CONCLUSIONS

Clinical predictors of worse long-term outcome included diabetes mellitus, higher angina score at follow-up, smaller stent deployment balloon size and greater number of stents at implantation. During follow-up, the majority of adverse events and stent-site revascularizations occurred early after stenting, and disease progression in nonstented vessels accounted for the majority of late revascularization events.

A randomized clinical trial of the effect of bed position after PTCA

BACKGROUND

After percutaneous transluminal coronary angioplasty, prolonged supine bedrest with the bed flat frequently causes back pain. This study was conducted to examine whether percutaneous transluminal coronary angioplasty patients could adjust their bed position to make themselves comfortable without increasing the frequency or severity of bleeding complications.

OBJECTIVES

To determine whether the risk of bleeding increased in patients who were allowed to use their bed controls to make themselves comfortable, and if the difference in comfort was significant between patients who controlled and elevated their bed position and patients who remained flat in bed.

METHOD

A randomized clinical trial was conducted; 54 patients undergoing percutaneous transluminal coronary angioplasty were randomly assigned to either the control group, in which patients remained flat in bed, or the experimental group, in which they controlled their bed position. Outcome measures included amount of bleeding at the catheter sites and patient comfort.

RESULTS

No difference in the amount of bleeding at catheter insertion sites was found between the two groups. Few subjects reported pain at any time. Back pain at dinner and bedtime was higher in the control group, but only the bedtime difference was statistically significant.

CONCLUSION

We conclude that patients may be allowed to adjust their bed position to 30 degrees for comfort without incurring increased risk of catheter entry site bleeding and that requiring patients to remain flat in bed has no scientific basis.

Patient selection reduces thrombotic complications of emergent stenting for failed PTCA

A comparison of consecutive initial and later patients receiving emergent coronary artery stents to salvage failed PTCA procedures was made to determine whether experience with this procedure can improve patient outcome. Twenty-six consecutive patients underwent emergent, unplanned implantation of one or more Palmaz-Schatz coronary stents at our institution over a 3-1/2 year period. Indications for stent insertion included impending vessel closure (decrease in TIMI flow grade and clinical evidence of ischemia) or acute occlusion (TIMI flow grade 0 or 1 and > or = 99% stenosis) after PTCA. Immediate and final success (30 day) were determined, and the results in the first (Initial) 13 patients were compared to the remaining (Later) 13 patients. Baseline characteristics of the study population included a male predominance (69%) with a mean (+/- SD) age of 57 +/- 10 years. Conventional balloon PTCA was performed in all three native coronary arteries with an increase in mean percentage stenosis from 76 +/- 13 to 85 +/- 14% (P < 0.05). Twelve patients developed acute occlusion and 14 patients impending closure after PTCA due to the appearance of thrombus (12%), dissection (46%), or both (35%). Palmaz-Schatz stents were successfully inserted in all patients restoring TIMI grade 3 antegrade flow; however, major complications developed in almost 50% of patients. Comparison of initial and later patients showed no differences in demographic or pre-PTCA angiographic characteristics. Later patients had less severe stenoses post-PTCA (before stenting) and were less likely to have thrombus present at the angioplasty site (15% vs. 77%, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term angiographic and clinical outcome after implantation of a balloon-expandable stent in the native coronary circulation. Palmaz-Schatz Stent Study Group

OBJECTIVES

The purpose of this study was to examine the long-term clinical and angiographic outcome after coronary stent implantation.

BACKGROUND

Previous reports have shown a discordance between the excellent initial angiographic results and subsequent adverse clinical events after coronary artery stenting.

METHODS

Single Palmaz-Schatz stents were electively implanted in the native coronary arteries of 300 consecutive patients. Angiograms were obtained at baseline, after balloon angioplasty, after stent implantation and at 6 months after implantation. Films were analyzed by a panel of angiographers utilizing an automated edge detection program. Clinical events, including death, myocardial infarction, coronary bypass surgery and repeat angioplasty, were recorded for 1 year.

RESULTS

Although there were no acute in laboratory vessel closures, stent thrombosis occurred in 14 patients (4.7%) at a mean +/- SD of 5 +/- 3 days after implantation. Two hundred fifty-eight (90%) of 286 eligible patients had follow-up angiography at 6.1 +/- 2.2 months after stent implantation. Minimal lumen diameter increased from 0.80 +/- 0.39 mm at baseline to 1.65 +/- 0.51 mm after angioplasty and further increased to 2.55 +/- 0.49 mm after stent placement (p = 0.0001). At follow-up there was a 0.85-mm late loss in lumen diameter, with a final minimal lumen diameter at 6 months of 1.70 +/- 0.71 mm. Restenosis, defined as > or = 50% diameter stenosis at follow-up, occurred in 14% of patients with previously untreated lesions and in 39% of patients with previous angioplasty (p < 0.001). Clinical events after 1 year for the entire group of 300 patients included death in 0.7%, myocardial infarction in 3.7%, bypass grafting in 8% and repeat angioplasty in 13%. Freedom from any adverse clinical event was 80% for all treated patients and 87% for those with previously untreated lesions.

CONCLUSIONS

Elective use of this balloon-expandable stent in the native coronary circulation is associated with a low restenosis rate by quantitative angiography in previously untreated lesions and a favorable clinical outcome with an excellent event-free survival rate at 1 year.

Comparison of results of intracoronary stenting in patients with unstable vs. stable angina

Percutaneous transluminal coronary angioplasty (PTCA) has higher complication and restenosis rates when performed in the setting of unstable angina. Balloon-expandable intracoronary stenting is a new technique with the potential to improve the results of PTCA. In order to determine whether stenting is associated with a poorer outcome in patients with unstable angina, we retrospectively examined our experience with the Palmaz-Schatz balloon-expandable intracoronary stent in 105 patients. Patients were divided into 2 groups on the basis of symptoms at the time of stent insertion: group I (n = 57) had stable angina pectoris, and group II (n = 48) had unstable angina defined as pain at rest despite antianginal therapy (Braunwald class II, III). Initial (30-d) and final (6-mo) success rates were defined as stent insertion without myocardial infarction, need for bypass surgery, death, and significant angina. Baseline characteristics were similar, although the patients with unstable symptoms were older, more likely to be female, and had a higher incidence of postinfarction angina. A total of 136 stents were successfully delivered to 97 target sites in 92% of patients. Major complications occurred in 4 patients (4%) and were due to subacute thrombosis in 3 of them. There were no differences in complication rates between patients receiving stents electively with stable vs. unstable symptoms (2% vs. 6%, p = NS). Six-mo. follow-up status was ascertained in 96% of patients and revealed overall clinical success in 83% with angiographic restenosis (> or = 50% stenosis) in 28% of patients. There were no significant differences between groups in rates of restenosis, follow-up angina class, or overall clinical success.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of low- with high-osmolality contrast agents in cardiac angiography. Identification of criteria for selective use

BACKGROUND

Controversy exists as to whether low-osmolality radiographic contrast agents, which have less detrimental pharmacological effects but are considerably more expensive than high-osmolality agents, should be used universally or only for selected high-risk patients.

METHODS AND RESULTS

A randomized, double-blind study was used to compare the frequency and severity of adverse events in 2245 consecutive patients undergoing diagnostic cardiac angiography. Two thousand one hundred sixty-six patients were successfully randomized to either iohexol, a low-osmolality contrast agent, or diatrizoate (as Hypaque 76), a high-osmolality agent. The end point event included clinically important adverse events (which jeopardized the patient or required aggressive treatment), contrast agent-related procedure abbreviations, and conversion to open-label contrast agent. Clinically important end point events were associated with increased age, New York Heart Association functional class, left ventricular end-diastolic pressure, arteriovenous oxygen difference, severity of coronary artery disease, and history of a previous reaction to contrast agent. End point events were less frequent in patients receiving iohexol (2.6% versus 4.6%; adjusted odds ratio, 1.59; 95% confidence interval, 0.97-2.60; P = .07). The difference in event frequency between iohexol and diatrizoate was confined to the highest-risk quartile of the patient population. An algorithm was developed to classify patients as being at high or low risk for an event based on patient age, New York Heart Association class, history of a prior contrast reaction, and left ventricular end-diastolic pressure. Application of this algorithm for selective use of low-osmolality agents only for high-risk patients to a theoretical population of 1000 patients reduced contrast agent costs 66% without increasing the frequency of contrast agent-related adverse events.

CONCLUSIONS

The advantages of low-osmolality contrast agents are clinically important in patients with severe heart disease but are not in less ill patients. Universal use of low-osmolality agents for cardiac angiography in an unselected population is not necessary. Appropriately guided selective use of low-osmolality contrast agents is feasible and has the potential to reduce cost substantially without compromising safety or effectiveness.

Fate of lesion-related side branches after coronary artery stenting

OBJECTIVES

The aim of this study was to assess the immediate and long-term patency of lesion-associated side branches after coronary artery stenting.

BACKGROUND

The possible adverse effects related to implantation of coronary stents are not completely known. An important potential complication of stenting is side branch occlusion due to mechanical obstruction or thrombosis.

METHODS

Serial coronary angiography was performed in 153 patients (167 lesions) at baseline, after conventional balloon angioplasty, immediately after Palmaz-Schatz stent placement and at 6 months. The patency of side branches, where present, was analyzed at each of these points.

RESULTS

Of 167 lesions stented, 57 stent placements spanned 66 side branches with a diameter > or = 1 mm. Twenty-seven (41%) of these side branches had > or = 50% ostial stenosis before standard balloon angioplasty. Six side branches became occluded after standard balloon angioplasty and remained occluded after stenting. Of the 60 side branches patent after conventional angioplasty, 57 (95%) remained patent immediately after stenting. All three side branches that became occluded after stenting had > or = 50% ostial stenosis at baseline. All 60 side branches, including the 3 initially occluded after stenting, were patent at 6-month follow-up.

CONCLUSIONS

These findings demonstrate that 1) acute side branch occlusion due to coronary stenting occurs infrequently; 2) when side branch occlusion occurs, it is associated with intrinsic ostial disease; and 3) the patency of side branch ostia is well maintained at long-term follow-up.

Intravascular ultrasonographic assessment of the results of coronary artery stenting

We studied 12 patients undergoing elective coronary stent implantation for either recurrent restenosis or adverse lesion appearance. By use of a 4.8F 20 MHz intravascular ultrasound catheter, the conventional angioplasty site was examined before and after coronary stent implantation. Quantitative angiographic analysis revealed the expected excellent final result with a group mean poststent diameter reduction of 14 +/- 9% and a cross-sectional area reduction of 22 +/- 13%. Angiographic analysis also indicated an increase in minimum stenosis diameter from 1.8 +/- 0.6 mm after conventional balloon angioplasty to 2.8 +/- 0.3 mm after coronary stent implantation. Quantitative analysis of the corresponding intravascular ultrasound images, however, revealed significant residual endoluminal obstruction. Fractional plaque area remained unchanged from 30 +/- 12% after conventional balloon angioplasty to 32 +/- 11% after stent implantation. The circumferential distribution of plaque increased significantly from 0.44 +/- 0.17 to 0.55 +/- 0.15 (p = 0.03) after stent implantation. Despite the lack of significant change in the ultrasound-determined minimum stenosis diameter after stent placement, there was a borderline significant increase in the plaque-free lumen area (before stent, 6.35 +/- 1.55 mm2; after stent, 7.25 +/- 1.6 mm2; p = 0.06). Thus, in contrast to the substantial improvement in the angiographically assessed residual luminal obstruction after stent implantation compared with the prestent condition, considerably less improvement was found by intravascular ultrasound-assessed examination. Morphometric analysis indicated a tendency toward circumferential remodeling of plaque. The inherently different approaches to vascular imaging represented by contrast angiography and intravascular ultrasound techniques appear to provide complementary information.(ABSTRACT TRUNCATED AT 250 WORDS)

Restenosis after placement of Palmaz-Schatz stents in native coronary arteries. Initial results of a multicenter experience

BACKGROUND

Several metallic intracoronary stents are currently undergoing preliminary evaluation to ascertain potential benefit as means to reduce the 30-40% incidence of restenosis after balloon angioplasty.

METHODS AND RESULTS

To determine the incidence and correlates of restenosis after placement of Palmaz-Schatz stents in native coronary arteries in the first group of patients selected for this procedure, clinical and quantitative angiographic data from 206 consecutive patients (221 stenoses) with successful stent placement (diameter stenosis < 50%) were analyzed. Six patients (2.9%) had thrombosis-mediated stent closure within 1 month after stent placement and were excluded from long-term angiographic follow-up. One hundred eighty-one (91%) of the remaining 200 patients had angiography at 5.8 +/- 2.1 months. Patients with and without follow-up did not differ in any baseline characteristic; in particular, history of restenosis at the site stented (73% versus 65%), placement of multiple overlapping stents (17% versus 20%), and mean poststent diameter stenosis (16 +/- 12% versus 14 +/- 12%). The overall incidence of restenosis (diameter stenosis > or = 50% at follow-up) in this group at high risk for restenosis was 36% (95% confidence interval, 29-43%) on a per-stenosis basis. The incidence of restenosis when a single stent was placed was 30% (95% confidence interval, 23-37%). Risk was dependent upon a history of restenosis (present versus absent 36% versus 16%, p = 0.02) and upon whether or not a poststent stenosis < or = 0% was achieved (6% versus 33%, p = 0.02). When multiple overlapping stents were placed, restenosis occurred at 64% of sites, and placement of multiple stents was discouraged during the later phases of this study as these results became apparent.

CONCLUSIONS

Although multiple stents appear to yield a poor long-term result, placement of single stents may offer a benefit compared with standard coronary angioplasty, particularly if an excellent angiographic result can be obtained in patients without prior restenosis. Further randomized trials in such patients are needed.

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.

Effect of intracoronary stenting on intimal dissection after balloon angioplasty: results of quantitative and qualitative coronary analysis

The effect of the Palmaz-Schatz stent on the angiographic appearance and residual luminal stenosis in patients with intimal dissection after balloon angioplasty was evaluated in 84 consecutive patients (90 lesions). Coronary angiography was performed before angioplasty, after conventional angioplasty and after stent implantation. The degree of intimal disruption was assessed as follows: grade 0, no dissection; grade 1, simple dissection (intraluminal linear defect or extraluminal cap extravasation); or grade 2, complex dissection (nonlinear spiral defect or luminal defect with multiple irregular borders). Quantitative coronary analysis of digitized cineangiograms was performed with use of a computerized automatic edge detection algorithm. After balloon angioplasty, 31 (34%) of 90 lesions demonstrated intimal dissection (18 simple, 13 complex). After stent implantation, intimal dissection improved by greater than or equal to 1 grade in 29 (94%) of the 31 lesions with 27 (87%) reduced to grade 0 (that is, no dissection). Dissection grade improved after stenting in 16 (89%) of 18 simple dissections and in all 13 complex dissections. Mean diameter stenosis was 77 +/- 17% before angioplasty, 47 +/- 17% after angioplasty and 14 +/- 10% after stenting (before angioplasty vs. after angioplasty and after angioplasty vs. after stenting, p less than 0.0001). In conclusion, intracoronary stenting is effective in reducing the residual luminal stenosis and in improving the angiographic appearance of intimal dissections after conventional balloon angioplasty.

Restenosis after coronary angioplasty: a multivariate statistical model to relate lesion and procedure variables to restenosis. The M-HEART Investigators

The Multi-Hospital Eastern Atlantic Restenosis Trial group obtained follow-up angiography in 510 patients with 598 successfully dilated coronary lesions who were enrolled in a controlled trial of the effects of a single dose of 1 g of methylprednisolone on restenosis after coronary angioplasty. The overall restenosis rate was 39.6%. The strongest univariate relations to the restenosis rate were found for lesion location (saphenous vein graft, 68%; left anterior descending artery, 45%; left circumflex artery and right coronary artery, 32%; p = 0.002); lesion length (less than or equal to 4.6 mm, 33%; greater than 4.6 mm, 45%; p = 0.001); percent stenosis before angioplasty (less than or equal to 73%, 25%; greater than 73%, 43%; p = 0.005), percent stenosis after angioplasty (less than or equal to 21%, 33%; greater than 21%, 46%; p = 0.017) and arterial diameter (less than 2.9 mm, 44%; greater than or equal to 2.9 mm, 34%; p = 0.036). Two multivariate models to predict restenosis probability were developed with use of stepwise logistic regression. The preprocedural model, which included only variables whose values were known before angioplasty, entered lesion length, vein graft location, left anterior descending artery location, percent stenosis before angioplasty, eccentric lesion and arterial diameter. The postprocedural model, which also included variables whose values were known after angioplasty was performed, was similar to the preangioplasty model except that it also entered postangioplasty percent stenosis and "optimal" balloon sizing but did not enter eccentric lesion. These data indicate that the probability of restenosis after angioplasty is determined predominantly by the characteristics of the lesion being dilated. They are consistent with the known intimal proliferative mechanism of restenosis, offer a means of identifying lesions at unusually high or low risk of restenosis, and of predicting the likelihood that a particular lesion will restenose after angioplasty and provide a rationale for stratification by restenosis probability in the design of future studies of restenosis.

Choice of contrast agents for cardiac angiography: review and recommendations based on clinically important distinctions

Low osmolal contrast agents (LOCA) are measurably superior to high osmolal contrast agents (HOCA) in a number of properties. However, LOCA are substantially more expensive than HOCA, and universal use of LOCA for cardiac angiography would strain the health care budget. Therefore, the choice to use LOCA in place of HOCA should be based on clinically important differences. Review of available published data suggests that HOCA can be used safely and effectively for cardiac angiography in patients with mild or moderately severe heart disease. When HOCA are used, those that do not bind calcium should be chosen as they cause fewer clinically important adverse reactions than those that do bind calcium. Use of LOCA may offer added safety in high risk patients, although to date, this conclusion has not been proved with clinical experience. Nonionic LOCA may be safer to use than ionic LOCA.