Autoperfusion balloon versus stent for acute or threatened closure during percutaneous transluminal coronary angioplasty

A randomized controlled clinical trial of prolonged balloon inflation during stent deployment strategy in primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: a pilot study

Background

Primary percutaneous coronary intervention (PPCI) is the standard procedure for reperfusion for ST-segment elevation myocardial infarction (STEMI), but the occurrence of the no-reflow phenomenon remains common and is associated with adverse outcomes.

Aims

This study aimed to evaluate whether prolonged balloon inflation in stent deployment would lessen the occurrence of the no-reflow phenomenon in PPCI compared with conventional rapid inflation/deflation strategy.

Methods

Patients were randomly assigned to either the prolonged balloon inflation in stent deployment group (PBSG) or conventional deployment strategy group (CDSG) in a 1:1 ratio. A subset of patients was included in the cardiac magnetic resonance (CMR) assessment.

Results

Thrombolysis in MI (TIMI) flow grade 3 was found in 96.7% and 63.3% of the patients of the PBSG and CDSG, respectively (P = 0.005). The results of the PBSG and CDSG are respectively shown as follows: 0% versus 30% no-reflow or slow flow (P = 0.002); 90% versus 66.7% ST-segment resolution ≥ 50% (P = 0.028); 35.6 ± 14.5 frames versus 49.18 ± 25.2 frames on corrected TIMI frame count (P = 0.014); and 60% versus 20% myocardial blush grade 3 (P = 0.001). At 1 month, the major cardiovascular adverse event (cardiovascular mortality) rate was 3.3% in both groups; at 1 year, the rate was 3.3% and 6.7% for the PBSG and CDSG, respectively (P = 1.00). In the CMR subset of cases, the presence of microvascular obstruction (MVO) was detected in 6.7% and 50% of the patients in the PBSG and CDSG, respectively (P = 0.023).

Conclusion

In our pilot trial, prolonged balloon inflation during stent deployment strategy in PPCI reduces the occurrence of the no-reflow phenomenon in patients with STEMI and improved the myocardial microcirculation perfusion (ClinicalTrials.gov number: NCT03199014; registered: 26/June/2017).

Impact of operator volume on overall major adverse cardiac events following direct coronary stent implantation versus stenting after predilatation

OBJECTIVES

To determine the impact of operator experience on procedural, clinical and angiographic outcome after (direct) coronary stent implantation.

BACKGROUND

Although for other forms of percutaneous coronary interventions an inverse relationship between operator volume and patient outcomes has been shown, the impact of operator volume on outcome after direct stenting has never been investigated.

METHODS

A retrospective analysis was performed on data from a prospective randomized trial comparing direct stenting with that after predilatation. The trial consisted of 400 patients with stable and unstable angina pectoris and/or myocardial ischemia due to a coronary stenosis of a single native vessel eligible in 1999-2001 for direct stenting. For a single-center high-volume clinic (>1500 cases/year), the authors compared the most experienced operators (case load: >4000) with well trained practitioners (case load: 175). One hundred and fifteen patients were identified who were treated by high-volume and 180 who were treated by medium-volume operators.

RESULTS

Baseline patient characteristics were evenly distributed among groups. High-volume, compared with medium-volume operators, were faster (30.8 versus 42.2 minutes, p < 0.001), needed less frequent postdilatation (15% versus 24%, p = 0.06) and had lower fluoroscopy times (7.5 versus 11.2 minutes, p < 0.001), lower contrast usage (180 versus 228 ml, p < 0.001), lower procedural costs (euro1982 versus euro2164, p = 0.05) and reduced rates of major adverse cardiac and cerebral event (MACCE) at six months (12.2 versus 21.1%, p = 0.03). The medium-volume operator group experienced higher angiographic binary restenosis rates after direct stenting compared with stenting after predilatation (31.5 versus 14.9%, p = 0.005).

CONCLUSIONS

Stenting performed by high-volume operators resulted in a 50% reduction in MACCE as compared with medium-volume physicians, which also had twice as much restenosis when using direct stenting. Hence, the more demanding technique of direct stenting should not be performed by unsupervised operators who have not yet completed their training. Furthermore, prolonged training periods and even more intensive supervision by experienced operators seems mandatory.

Impact of interventionalist volume, experience, and board certification on coronary angioplasty outcomes in the era of stenting

It has been suggested that percutaneous coronary intervention (PCI) by high-volume operators may be associated with better outcomes. However, the relation between operator and outcome is confounded by hospital caseloads of PCI, with busier hospitals generally having better outcomes. We assessed the effect of operator characteristics (volume of PCI, years in practice, and board certification status) on contemporary outcomes of PCI in a busy center with high-volume operators. Between 1999 and 2001, 12,293 PCIs were performed at our center by 28 interventionalists. Patients' clinical risk was assessed with the previously validated Beaumont PCI Risk Score. Operators were classified as producing low, medium, or high volume (tertiles of annual PCI volume < or =92, 93 to 140, or >140, respectively), as less, medium, or great experience (tertiles of years in practice < or =8, 9 to 14, or >14 years, respectively), and board certified (68%) or not. In-hospital death rate and a composite end point (death, coronary artery bypass graft surgery, myocardial infarction, or stroke) occurred in 0.99% and 2.59% of patients, respectively. Operator volume, experience, and board certification showed no univariate or multivariate relation with the study end points. The Beaumont PCI Risk Score showed a strong independent relation with in-hospital death rate (adjusted odds ratio 1.37, 95% confidence interval 1.31 to 1.43, p <0.0001) and composite end point (odds ratio 1.19, 95% confidence interval 1.16 to 1.22, p <0.0001). We conclude that, in contemporary PCI practice at a large center with high-volume operators, in-hospital outcomes are not affected by operator volume, experience, or board certification. Rather, patients' clinical risk score is the overriding determinant of clinical outcomes. Our findings emphasize the power of a well-organized high-volume system to minimize the impact of operator factors on outcomes of PCI.

Clinical outcome of coronary angioplasty in patients with ischaemic cardiomyopathy

OBJECTIVE

To assess the clinical outcome of successful percutaneous transluminal coronary angioplasty (PTCA) in patients with poor ventricular function.

METHODS

Analysis of angiographic, echocardiographic and clinical records of patients with severe LV dysfunction who underwent PTCA from January 1, 1995 to December 31, 1997 was undertaken. Forty-one patients aged 63+/-10 years, 36 men, all with significant coronary artery disease and impaired LV function (fractional shortening, FS<or=20%) were identified. Patients' data before and after angioplasty were analyzed.

RESULTS

Post PTCA: angiographic success was 95.2%. Major complications occurred in 19.5% and hospital mortality was 2.7%. At 6 months after PTCA:LV fractional shortening (FS) increased from 15.9+/-3.4% to 19.6+/-6.6%, P=0.02 and consequently cardiac output from 4.28+/-0.98 to 5.34+/-1.77 l/min, P<0.01. Change in at least one class of angina and cardiac functional status was observed in 46% of patients, P<0.001, and this was maintained to the end of the year. After 12 months follow-up: restenosis occurred in 10.8%; mortality was 5.4%; event-free and actuarial survivals were 62.3% and 91.9%, respectively.

CONCLUSIONS

In patients with severe LV dysfunction, continued symptomatic improvement can be achieved with successful coronary angioplasty. This is associated with significant recovery of LV systolic function and cardiac output. In order to minimize procedure-related complications, careful patient selection should be considered.

Immediate stent implantation versus conventional techniques for the treatment of abrupt vessel closure or symptomatic dissections after coronary balloon angioplasty

BACKGROUND

Coronary stenting was initially designed to treat a bailout scenario. Prospective randomized trials comparing stent implantation with standard techniques, including emergency coronary artery bypass grafting, are lacking. The aim of this trial was to test the superiority of immediate stent implantation compared with standard techniques for the treatment of abrupt or threatening closure after coronary balloon angioplasty.

METHODS

In a prospective trial, 100 patients with abrupt vessel closure or symptomatic dissections causing objective signs of ischemia were randomly assigned to treatment with immediate placement of stents (n = 51) versus standard techniques such as prolonged dilatation or emergency bypass surgery (n = 49). The primary end point was the achievement of successful stabilization not requiring crossover to the other study group. Secondary end points included event-free survival and restenosis.

RESULTS

Successful stabilization was achieved in 94% of patients in the stent group compared with 78% of patients in the standard treatment group (P =.038). Two patients died in each group, and there was a trend toward a higher incidence of myocardial infarction (16% vs 8%; P =.163) and a significantly increased creatine phosphokinase level (245 IU/L [95% confidence interval, 217-265 IU/L] vs 179 IU/L [confidence interval 140-212 IU/L]; P =.0002) in the standard treatment group. Event-free survival after 250 days was 72% in the stent group compared with 29% in the standard treatment group (P =.001). The angiographic restenosis rate was 30% in the stent group versus 59% in the standard treatment group (P =.01).

CONCLUSIONS

Immediate stenting, if technically feasible, shows superior short- and long-term results compared with standard treatment options.

The relationship between operator volume and outcomes after percutaneous coronary interventions in high volume hospitals in 1994-1996: the northern New England experience. Northern New England Cardiovascular Disease Study Group

OBJECTIVES

The purpose of this study was to examine the relationship between annual operator volume and outcomes of percutaneous coronary interventions (PCIs) using contemporaneous data.

BACKGROUND

The 1997 American College of Cardiology (ACC)/American Heart Association task force based their recommendation that interventionists perform > or = 75 procedures per year to maintain competency in PCI on data collected largely in the early 1990s. The practice of interventional cardiology has since changed with the availability of new devices and drugs.

METHODS

Data were collected from 1994 through 1996 on 15,080 PCIs performed during 14,498 hospitalizations by 47 interventional cardiologists practicing at the five high volume (>600 procedures per hospital per year) hospitals in northern New England and one Massachusetts-based institution that support these procedures. Operators were categorized into terciles based on their annualized volume of procedures. Multivariate regression analysis was used to control for case-mix. In-hospital outcomes included death, emergency coronary artery bypass graft surgery (eCABG), non-emergency CABG (non-eCABG), myocardial infarction (MI), death and clinical success (> or = 1 attempted lesion dilated to < 50% residual stenosis and no death, CABG or MI).

RESULTS

Average annual procedure rates varied across terciles from low = 68, middle = 115 and high = 209. After adjusting for case-mix, clinical success rates were comparable across terciles (low, middle and high terciles: 90.9%, 88.8% and 90.7%, Ptrend = 0.237), as were all the adverse outcomes including death (low-risk patients = 0.45%, 0.41%, 0.71%, Ptrend = 0.086; high-risk patients = 5.68%, 5.99%, 7.23%, Ptrend = 0.324), eCABG (1.74%, 2.05%, 1.75%, Ptrend = 0.733) and MI (2.57%, 1.90%, 1.86%, Ptrend = 0.065).

CONCLUSIONS

Using current data, there is no significant relationship between operator volumes averaging > or = 68 per year and outcomes at high volume hospitals. Future efforts should be directed at determining the generalizability of these results.

Effect of transient abrupt vessel closure during otherwise successful angioplasty for unstable angina on clinical outcome at six months. Hirulog Angioplasty Study Investigators

OBJECTIVES

The objective of this study was to identify predictors of major adverse cardiac events after successful coronary angioplasty.

BACKGROUND

The acute complications of angioplasty are related to baseline clinical and angiographic variables, and early complications adversely affect long-term outcome. However, the predictors of enduring success after uncomplicated angioplasty are less well defined.

METHODS

Of 4,098 patients undergoing angioplasty in the Hirulog Angioplasty Study, 3,899 (95%) had a successful procedure without in-hospital death, emergent bypass surgery or clinical evidence of myocardial infarction. Baseline and procedural variables for these 3,899 patients were examined.

RESULTS

Major adverse cardiac events occurred in 22% of the patients with initially successful procedures at 6 months: death in 1%, myocardial infarction in 2% and repeat revascularization in 21%. Univariable predictors of increased events included successful salvage from abrupt vessel closure (p < 0.001), emergency stenting (p < 0.001), multilesion angioplasty (p < 0.001), diabetes (p=0.02), target lesion in the left anterior descending artery (p=0.02), unstable angina (p=0.03) and smaller final luminal diameter (p=0.04). There was a trend toward increased events among patients with prior angioplasty (p=0.08), but asymptomatic elevation of the creatine kinase was not predictive (p=0.5). In a multivariable model, abrupt vessel closure was the strongest independent predictor of major adverse cardiac events at 6 months (p < 0.001; odds ratio [95% confidence interval]=3.6 [2.5 to 5.1]), while multivessel angioplasty, target lesion in the left anterior descending artery and diabetes also remained independent predictors (all p < or = 0.02).

CONCLUSIONS

This analysis suggests that "uncomplicated" abrupt vessel closure is a powerful predictor of adverse clinical outcome following successful angioplasty. Improved techniques to reduce abrupt closure during angioplasty are thus urgently needed, and patients who experience "uncomplicated" closure require closer surveillance during follow-up.

Long-term analysis of conventional coronary balloon angioplasty and an initial "stent-like" result. The NHLBI PTCA Registry

OBJECTIVES

We examined the influence of an initial "stent-like" result on long-term outcome in patients in the 1985-86 NHLBI PTCA Registry.

BACKGROUND

Stent use in selected patients is associated with improved angiographic and short-term clinical outcome; however, due to potential for in-stent restenosis and high costs of stents, there is interest in a strategy of more optimal dilatation to achieve a "stent-like" result without a stent. The long-term outcome of patients with a "stent-like" percutaneous transluminal coronary angioplasty (PTCA) remains unknown.

METHODS

Ten-year outcome was compared between 225 successfully treated patients with and 1,764 successfully treated patients without an initial "stent-like" result ( > or = 1 lesion dilated to < or = 10% stenosis). The sample had 75% and 80% power, respectively, to detect an absolute difference of 8% in the 10-year rate of death and myocardial infarction (MI) between the two groups.

RESULTS

Ten-year rates of death and MI were similar between the stent-like and non-stent-like groups (22.3% vs. 22.2%, 17.6% vs. 17.9%), however, there was less target lesion revascularization in the stent-like group (30.2% vs. 36.8%). In subgroup analysis of patients with multivessel disease, those with a stent-like result had less follow-up bypass surgery (25.2% vs. 32.7%), yet more repeat PTCA (53.8% vs. 42.7%). These findings were unaffected by adjustment for differences in baseline characteristics between the two patient groups.

CONCLUSIONS

Achievement of an initial stent-like result via balloon angioplasty alone may not appreciably reduce the long-term risk of death or MI, nor confer equivalent clinical benefit as achieving a stent-like result with a stent.

Novel perfusion sleeve for use during balloon angioplasty: initial clinical experience

The perfusion sleeve (PS) is an "over-the-balloon" catheter designed to add perfusion capability to standard PTCA catheters. To evaluate the clinical effectiveness of this device, eight patients underwent standard PTCA with the PS retracted in the guide (Inflation 1-Control) and after deployment of the PS (Inflation 3-Control). Between standard inflations the PS was advanced and aligned with the already positioned PTCA balloon which was inflated for up to 15 minutes (Inflation 2-Perfusion). TIMI III flow was present in 5/7 and TIMI II flow in 2/7 patients during Inflation 2-Perfusion. Absolute ST segment shift (mm) on the ECG was significantly less at 3 minutes and prior to balloon deflation with the PS in place (1.0 +/- 1.4 and 1.1 +/- 1.1 mm) compared to Inflation 1-Control and Inflation 3-Control (2.6 +/- 1.3 and 2.3 +/- 0.3 mm) respectively (P < or = 0.05). Use of the PS in conjunction with standard PTCA is feasible, provides perfusion during prolonged balloon inflations and reduces the magnitude of ischemia.

New devices enhance hospital results of coronary angioplasty

After rigorous screening by means of registries and controlled trials, various atherectomy devices, excimer laser catheters, and endoluminal stents were approved for general clinical use. Few data are available describing their safety and effectiveness after approval. This analysis was undertaken to assess the impact on patient outcomes of the unrestricted clinical application of new transcatheter devices for coronary angioplasty. Thirty-six cardiologists performed 3,113 transcatheter procedures during 1995. Each chose the transcatheter modality best suited to the clinical and angiographic features of the patient. Baseline clinical and angiographic data and initial outcome were recorded by cardiac catheterization laboratory personnel. In-hospital events were obtained by independent chart review. Balloon angioplasty alone was employed in 1,089 (35.0%) patients. A stent was deployed after balloon angioplasty in 1,029 (33.1%) patients. An atherectomy or laser device was used without stent support in 631 (20.3%) patients, and stent support was added in an additional 364 (11.7%) patients. In all three new device categories the angiographic success (final luminal narrowing <50%) rate was better than in balloon angioplasty for type-C lesions and for chronic occlusions. The frequency of adverse events in the aggregate was not increased with device use, but the frequency of coronary artery bypass surgery was reduced with stent use. The frequency of non-Q-wave myocardial infarction was greater with devices than with balloon angioplasty alone. After adjustment for the differences in baseline clinical and angiographic variables by means of multivariate analysis, each of the three new device categories was independently associated with an increased chance of angiographic and procedural success compared to balloon angioplasty. The availability of new transcatheter devices for clinical practice enhances patient outcomes during hospitalization for the procedure.

Abrupt vessel closure: changing importance, management, and consequences

Percutaneous coronary interventions have been performed for 20 years. Despite the success and progress of these interventions, abrupt vessel closure has been a dramatic adverse event of coronary interventions. Closure has frequently led to the major complications of death, myocardial infarction, and emergency coronary artery bypass. Because of the fear of this adverse event and its subsequent complications, the applicability of coronary interventions is sometimes limited. The pathologic characteristics of abrupt vessel closure have been recognized as predominantly caused by dissection, with vessel recoil and thrombus formation playing important secondary roles. The recognition of the lesions at risk for abrupt vessel closure has led to a strategy of lesion-specific device therapy to reduce complications. Similarly the role of antiplatelet and antithrombotic therapies have reduced complications. The earliest methods of dealing with abrupt closure was emergency coronary artery bypass surgery with significant rates of morbidity and mortality. With the advent of second-generation devices and techniques, particularly stents, the management of abrupt vessel closure has been simplified and alternatives to emergency coronary bypass are more available. This article will review the history and current status of the prevention and management of abrupt vessel closure and demonstrate that anticipation and management of this complication have been facilitated with reduction of subsequent complications and increased applicability of coronary interventions.

Coronary implantation of silicone-carbide-coated Palmaz-Schatz stents in patients with high risk of stent thrombosis without oral anticoagulation

Coronary stenting in bail-out situations is effective but associated with increased stent thrombosis and bleeding rates. Silicone-carbide coating reduces fibrinogen activation on alloplastic surfaces and thus may also reduce stent thromboses. A total of 44 patients received 58 silicone-carbide-coated stents for threatened (80%) or abrupt (20%) closure. In addition to heparin, patients were treated with aspirin and ticlopidine (75%) or aspirin (25%) only. Two patients (4.5%) died in the hospital. The combined in-hospital complication rate including death, emergency revascularization, stent-related myocardial infarction, and stent thrombosis was 9% (4 of 44 patients). Major bleeding occurred in 4 patients (9%). Six-month follow-up angiography was obtained in all eligible patients (42 of 44), revealing a restenosis rate of 21% (9 of 42). Thus, coronary implantation of silicone-carbide-coated stents is feasible in bail-out situations without oral anticoagulation and with a low complication rate. Further studies are required to optimize the anticoagulation regimen with this type of coating.

Coronary artery stenting: indications and cost implications

The practice of coronary stenting is evolving rapidly, with new stent designs, deployment techniques, and adjunctive therapy. In many respects, clinical practice is changing in advance of the availability of supporting data. The consistent excellent angiographic result with stent deployment exceeds that achieved by any other previous interventional device, and the extent to which this accounts for the exponential increase in stent utilization cannot be accurately determined but is undoubtedly considerable. Controlled randomized trials have confirmed that stent deployment is superior to balloon angioplasty in certain lesion subsets or clinical scenarios. These include focal de novo native vessel lesions, lesions with late recoil after balloon angioplasty, acute closure after balloon angioplasty, and proximal left anterior descending coronary artery lesions. In addition, observational data is persuasive in focal coronary saphenous vein graft lesions and aorto-ostial lesions. On the other hand, the evidence supporting the use of stents strictly to improve on a suboptimal result, possibly the most frequent indication, is indirect and circumstantial. Stents are expensive, but it was anticipated that with the reduction in restenosis not only would they be cost-effective but also ultimately would reduce costs. This hope has not as yet been realized. However, there is little question that the introduction of intracoronary stents has been the most significant and exciting development since the introduction of percutaneous revascularization almost 20 years ago. It has revitalized the field.

Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty

Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty (PTCA)-with an autoperfusion balloon or active system-facilitates prolonged balloon inflation. Prolonged inflations may tack up intimal dissections and improve the primary angioplasty result in complex lesions. Additionally, distal perfusion may reduce the likelihood of cardiogenic shock during high-risk PTCA. Autoperfusion balloons are most frequently used to treat acute or threatened closure. There currently is no prospective clinical study showing that stent implantation for this complication is more successful and more cost-effective. The blood flow rates through autoperfusion balloons may not abolish myocardial ischemia, and higher flow rates can often be achieved with pumps. Therefore, during high-risk PTCA, pumps may be preferred to prevent hemodynamic collapse. Clinical application of perfusion pumps is hampered by the risk for mechanical hemolysis during prolonged perfusion and the high velocity of the bloodstream that exits the PTCA catheter, causing distal vessel wall trauma.