Kissing Balloon-Stent Technique for Simple Bifurcation Lesions

Background: Coronary bifurcation lesions are commonly encountered during coronary angiography. The management of bifurcation lesions remains challenging, with various bifurcation techniques being available and outcomes varying depending on the Medina classification and operator experience. Methods: We present a short case series and the outcomes of a new bifurcation technique for the management of simple Medina '0,0,1' and '0,0,1' bifurcation lesions using the kissing balloon-stent technique (kissing BS). Results: We retrospectively identified 8 patients who underwent bifurcation stenting using the kissing Balloon-Stent technique, along with their clinical and angiographic follow-up outcomes. We also describe the benefits and limitations of the technique, delineate the potential mechanisms of target lesion failure, and outline appropriate patient selection. Conclusions: Kissing Balloon-Stent technique is a simple single stent technique that is safe and feasible in select patients with Medina '0,0,1' and '0,0,1' bifurcation lesions.

Effect of Alcohol-Mediated Renal Denervation on Blood Pressure in the Presence of Antihypertensive Medications: Primary Results from the TARGET BP I Randomized Clinical Trial

BACKGROUND

Renal denervation (RDN) has demonstrated clinically relevant reductions in blood pressure among individuals with uncontrolled hypertension despite lifestyle intervention and medications. The safety and effectiveness of alcohol-mediated RDN has not been formally studied in this indication.

METHODS

TARGET BP I is a prospective, international, sham-controlled, randomized, patient- and assessor-blinded trial investigating the safety and efficacy of alcohol-mediated RDN. Patients with office systolic blood pressure (SBP) ≥150 and ≤180 mmHg, office diastolic BP ≥90 mmHg and mean 24-hour ambulatory SBP ≥135 and ≤170 mmHg, despite prescription of 2-5 antihypertensive medications were enrolled. The primary endpoint was the baseline-adjusted change in mean 24-hour ambulatory systolic BP at 3 months post procedure. Secondary endpoints include mean between-group differences in office and ambulatory BP at additional time points.

RESULTS

Among 301 patients randomized 1:1 to RDN or sham control, RDN was associated with a significant reduction in 24-hour ambulatory SBP at 3 months (mean ± standard deviation -10.0 ± 14.2 mmHg versus -6.8 ± 12.1 mmHg, treatment difference -3.2 mmHg, 95% confidence interval [CI] -6.3, 0.0 mmHg; P=0.0487). Subgroup analysis of the primary endpoint revealed no significant interaction across predefined subgroups. At 3 months, the mean change in office SBP was -12.7 ± 18.3 mmHg and -9.7 ± 17.3 mmHg (difference, -3.0, 95% CI -7.0, 1.0; P=0.173), for RDN and sham, respectively. No significant differences in ambulatory or office diastolic BP were observed. Adverse safety events through 6 months were uncommon with 1 instance of accessory renal artery dissection in the RDN group (0.7%). No significant between-group differences in medication changes or patient adherence were identified.

CONCLUSIONS

Alcohol-mediated RDN was associated with a modest but statistically significant reduction in 24-hour ambulatory systolic BP compared with sham control. No significant differences between groups in office BP or 6-month major adverse events were observed.

Radial artery pseudoaneurysm rupture after cardiac catheterization

A 73-year-old man with history significant for paroxysmal atrial fibrillation on apixaban underwent percutaneous coronary intervention (PCI) of the left anterior descending artery via transradial access. The patient was discharged on clopidogrel, atorvastatin, carvedilol, isosorbide mononitrate, losartan, and apixaban.

Alcohol-mediated renal denervation in patients with hypertension in the absence of antihypertensive medications

BACKGROUND

Ultrasound and radiofrequency renal denervation (RDN) have been shown to safely lower blood pressure (BP) in hypertension.

AIMS

The TARGET BP OFF-MED trial investigated the efficacy and safety of alcohol-mediated renal denervation (RDN) in the absence of antihypertensive medications.

METHODS

This randomised, blinded, sham-controlled trial was conducted in 25 centres in Europe and the USA. Patients with a 24-hour systolic BP of 135-170 mmHg, an office systolic BP 140-180 mmHg and diastolic BP ≥90 mmHg on 0-2 antihypertensive medications were enrolled. The primary efficacy endpoint was the change in mean 24-hour systolic BP at 8 weeks. Safety endpoints included major adverse events up to 30 days.

RESULTS

A total of 106 patients were randomised; the baseline mean office BP following medication washout was 159.4/100.4±10.9/7.0 mmHg (RDN) and 160.1/98.3±11.0/6.1 mmHg (sham), respectively. At 8 weeks post-procedure, the mean (±standard deviation) 24-hour systolic BP change was â2.9±7.4 mmHg (p=0.009) versus â1.4±8.6 mmHg (p=0.25) in the RDN and sham groups, respectively (mean between-group difference: 1.5 mmHg; p=0.27). There were no differences in safety events between groups. After 12 months of blinded follow-up, with medication escalation, patients achieved similar office systolic BP (RDN: 147.9±18.5 mmHg; sham: 147.8±15.1 mmHg; p=0.68) with a significantly lower medication burden in the RDN group (mean daily defined dose: 1.5±1.5 vs 2.3±1.7; p=0.017).

CONCLUSIONS

In this trial, alcohol-mediated RDN was delivered safely but was not associated with significant BP differences between groups. Medication burden was lower in the RDN group up to 12 months.

Shock and Awe: Successful Revascularization with Intravascular Lithotripsy in Recurrent ST-Elevation Myocardial Infarction Secondary to Stent Under-Expansion

We report a case of recurrent ST-segment elevation myocardial infarction (STEMI) due to a previously implanted under-expanded stent with in-stent thrombosis refractory to traditional interventional techniques. We underscore the utility of bail-out shockwave intravascular lithotripsy to tackle previously under-expanded stents in this acute setting.

Real world single center experience with saphenous vein grafts interventions: should filters be filtered out?

BACKGROUND

Percutaneous coronary intervention (PCI) of saphenous vein grafts (SVG) can be challenging due to no reflow phenomenon from distal embolization of debris and microvascular vasoconstriction, resulting in myocardial injury post-procedure. Guidelines promote the use of distal embolic protection devices (EPD) to protect the distal arterial bed during SVG PCI. However, this approach has shown less-than-optimal results in many studies. We report our data using the Borgess protocol [prophylactic intracoronary (IC) nicardipine injection and direct stenting], as an alternative to EPDs in a large series of SVG interventions.

METHODS

This is a retrospective, cohort study of our single center experience with SVG interventions between 2017 and 2021. The primary outcome of the study was major adverse cardiovascular events (MACE) [a composite of death, emergent coronary artery bypass graft surgery (CABG), myocardial infarction (MI), and target vessel revascularization (TVR)] at 30 days post-procedure.

RESULTS

There were 424 consecutive SVG interventions performed during the study period, and 76% of cases presented with acute coronary syndrome. Full adherence to the Borgess protocol was observed in 36% of cases; IC nicardipine was utilized in 72% of cases. MACE rate was 3.5% at 30 days driven primarily by MI (2.6%).

CONCLUSION

The Borgess protocol approach to vein graft interventions proved good outcomes when compared to SVG PCI in randomized trials utilizing EPDs. Our study is limited by the retrospective nature and single center experience.

The Potential Role of Renal Denervation in the Management of Heart Failure

Sympathetic nervous system activation in patients with heart failure is one of the main pathophysiologic mechanisms associated with the worse outcomes. Pharmacotherapies targeting neurohormonal activation have been at the center of heart failure management. Despite the advancement of therapies and the available treatments, heart failure continues to have an overall poor prognosis. Renal denervation was originally developed to lower systemic blood pressure in patients with poorly controlled hypertension, by modulating sympathetic outflow. However, more recently, multiple studies have investigated the effect of renal denervation in heart failure patients with both preserved (HFpEF) and reduced ejection fractions (HFrEF). This paper provides an overview of the potential effect of renal denervation in altering the various pathophysiologic, sympathetically mediated pathways that contribute to heart failure, and reviews the literature that supports its future use in those patients.

Impact of drug adherence on blood pressure response to alcohol-mediated renal denervation

PURPOSE

While poor drug adherence is frequent in patients with resistant hypertension, detailed analyses of the impact of drug adherence on the success of renal denervation are scarce. We report drug adherence at baseline, changes in drug adherence, and the influence of these parameters on blood pressure changes at 6 and 12 months in patients treated with alcohol-mediated renal denervation as part of the Peregrine study.

MATERIALS AND METHODS

Urinary detection of antihypertensive drugs was performed using high-performance liquid chromatography-tandem mass spectrometry. Full adherence, partial adherence, and complete non-adherence were defined as 0, 1, or ≥2 drugs not detected, respectively.

RESULTS

Renal denervation was performed in 45 patients with uncontrolled hypertension on ≥3 antihypertensive medications (62% men, age 55 ± 10 years). At baseline, the proportion of fully, partially, and non-adherent patients was 62% (n = 28), 16% (n = 7), and 22% (n = 10), respectively. At 6 months, adherence improved by 21% (n = 9), remained unchanged at 49% (n = 21), and worsened by 30% (n = 13). Mean 24-h systolic blood pressure decreased by 10 ± 13, 10 ± 4, and 14 ± 19 mmHg in fully, partially, and non-adherent patients (p = 0.77), and by 14 ± 14, 8 ± 11, and 14 ± 18 mmHg in patients who improved, maintained, or decreased adherence, respectively (p = 0.35). The results at 12 months were similar.

CONCLUSION

About 40% of patients with apparently treatment-resistant hypertension were not fully adherent at baseline, and adherence decreased further in 30%. Nevertheless, mean blood pressure changes after renal denervation were similar irrespective of drug adherence. Our results suggest that such patients may benefit from alcohol-mediated renal denervation, irrespective of drug adherence. These findings are hypothesis-generating and need to be confirmed in ongoing sham-controlled trials.

Managing coronary artery perforation after percutaneous coronary intervention

INTRODUCTION

Coronary artery perforation is a serious complication during percutaneous coronary intervention that results in significant increase in morbidity and mortality. In this article, we provide a state-of-the-art overview of the contemporary management of coronary perforation and the possible scenarios that operators may run into during percutaneous coronary interventions.

AREA COVERED

Coronary perforation during percutaneous coronary intervention. Literature search was performed using PubMed and Google Scholar to identify the most recently published articles covering this topic.

EXPERT OPINION

As part of this review, we also provide an expert commentary discussing the nuances in the recognition and management of coronary artery perforation, in addition to future directions, and improvements in technology that could make the management of coronary perforation safer and more effective.

A Next-Generation Guide Extension System for Percutaneous Coronary Intervention

BACKGROUND

Guide catheter extension is an integral part of percutaneous coronary intervention (PCI). First generation guide catheter extension devices are monorail, blunt ended tubular structures with limitations. The CrossLiner™ is a next generation guide extension "system" intended to allow safe, deep, coronary intubation.

METHODS

The CrossLiner was tested in a head-to-head study with the GuideLiner™ and GuideZilla™ in a porcine coronary model, with stenting. Data were collected from 8 coronary vessels from four animals, to evaluate the ability to deeply intubate the vessel with the guide extension.

RESULTS

The CrossLiner crossed distally and through a distal stented segment in 8/8 vessels, while the first-generation devices were stuck proximal to the stent (n=2/8) or at the stent edge (n=4/8), or passed partially into the deployed stent with difficulty (2/8) vessels (p < 0.0002 for deliverability). The average depth of guide extension delivery/ "intubation" was 12.9±3.6 cm for the CrossLiner and 5.6±1.1 cm for the first-generation guide extension (p < 0.001).

CONCLUSIONS

The CrossLiner is a next generation guide extension system that may offer advantages over first generation devices. Further clinical evaluation will be required to assess the role of this new device in PCI.

Long-Term Results up to 12 Months After Catheter-Based Alcohol-Mediated Renal Denervation for Treatment of Resistant Hypertension

Supplemental Digital Content is available in the text.

Background:

Primary results of this prospective, open-label, multicenter trial suggested that alcohol-mediated renal denervation with perivascular injection of dehydrated alcohol using the Peregrine System Infusion Catheter safely reduces blood pressure (BP) in patients with resistant hypertension. To date, maintenance of the BP-lowering effect beyond 6 months using this novel technology has not been reported. This article describes the final, 12-month follow-up data on the safety and efficacy of alcohol-mediated renal denervation in these patients.

Methods:

Forty-five patients with resistant hypertension on a stable regimen of on average 5.1±1.5 antihypertensive medications underwent successful bilateral renal denervation using the Peregrine Catheter with alcohol as the neurolytic agent (0.6 mL per renal artery). Apart from 2 vascular access pseudoaneurysms (both without sequelae), no major procedural complications occurred.

Results:

At 12 months post-procedure, mean 24-hour ambulatory systolic and diastolic BP were reduced by 10 mm Hg (95% CI, −16 to −5) and 7 mm Hg (−10 to −3), respectively (P<0.001). Office systolic/diastolic BP was reduced by 20/10 mm Hg (−27, −13/−14, −6; <0.001). Compared with baseline, the number of antihypertensive medications was reduced in 21% of patients, while it was increased in 19%. From baseline to 12 months, serum creatinine, urea, cystatin C, and spot urine albumin levels remained unchanged. The change in estimated glomerular filtration rates (−3.9±10.3 mL/minute per 1.73 m² [95% CI, −7.1 to −0.75]; P=0.02) was within the expected range. There were no cases of renal artery stenosis up to 12-month follow-up.

Conclusions:

Catheter-based chemical renal denervation with dehydrated alcohol using the Peregrine Catheter seems to safely reduce BP at follow-up of up to 12 months. Further randomized and sham controlled studies are underway to further validate these findings.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02570113.

Blood pressure lowering with alcohol-mediated renal denervation using the Peregrine infusion Catheter is independent of injection site location

OBJECTIVES

The current analysis utilized core laboratory angiographic data from a prospective, single-arm, open-label, multi-center feasibility study to ascertain whether the location of alcohol infusion within main renal arteries during renal denervation (RDN) had an impact on the BP-lowering effect at 6 months.

BACKGROUND

The influence of the location of alcohol infusion during RDN, within the main renal artery (proximal, middle, or distal), on the magnitude of the blood pressure (BP) lowering is unstudied.

METHODS

The Peregrine Catheter was used to perform alcohol-mediated RDN with an infusion of 0.6 mL of alcohol per artery as the neurolytic agent in 90 main arteries and four accessory arteries of 45 patients with hypertension.

RESULTS

No relationship between the site of alcohol infusion and change from baseline in both office systolic and 24-hour systolic ambulatory BP (ABP) at 6 months was observed. When analyzed at the artery level, the least squares (LS) mean changes ± SEM from baseline to 6 months post-procedure in 24-hour systolic ABP when analyzed by renal arterial location were -11.9 ± 2.4 mmHg (distal), -10 ± 1.6 mmHg (middle), and -10.6 ± 1.3 mmHg (proximal) (all p < 0.0001 for change from baseline within groups). The results were similar for office systolic BP. There was no difference between treated locations (proximal is reference).

CONCLUSION

In this post-hoc analysis, the location of alcohol infusion within the main renal artery using the Peregrine system, with alcohol as the neurolytic agent for chemical RDN, did not affect the magnitude of BP changes at 6 months.

Catheter-based alcohol-mediated renal denervation for the treatment of uncontrolled hypertension: design of two sham-controlled, randomized, blinded trials in the absence (TARGET BP OFF-MED) and presence (TARGET BP I) of antihypertensive medications

BACKGROUND

Arterial hypertension is a common and life-threatening condition and poses a large global health burden. Device-based treatments have been developed as adjunctive or alternative therapy, to be used with or without antihypertensive medication for treating uncontrolled hypertension. The safety and feasibility of chemical renal denervation (RDN) using the Peregrine Catheter and alcohol were demonstrated in a first-in-man and open-label clinical trials, prompting the initiation of the ongoing TARGET BP OFF-MED and TARGET BP I trials.

DESIGN

The TARGET BP trials are randomized, blinded, sham-controlled trials designed to assess the safety and efficacy of alcohol-mediated RDN for the treatment of uncontrolled hypertension in the absence of antihypertensive medications (TARGET BP OFF-MED) or in addition to prescribed antihypertensive medications (TARGET BP I). Subjects with confirmed uncontrolled hypertension and suitable renal artery anatomy are randomized (1:1) to receive either RDN using the Peregrine Kit with alcohol (0.6 mL per renal artery) infused through the Peregrine Catheter or diagnostic renal angiography only (sham procedure). TARGET BP OFF-MED completed enrollment and randomized 96 subjects. TARGET BP I will randomize approximately 300 subjects and will transition to an open-label safety cohort of approximately 300 subjects receiving RDN once the primary efficacy endpoint of the Randomized Controlled Trial (RCT) cohort has been met. Primary endpoints are change in mean 24-hour ambulatory systolic blood pressure from baseline to 8 weeks (TARGET BP OFF-MED) and 3 months (TARGET BP I) post-procedure.

CONCLUSION

The TARGET BP trials are the first large-scale, international, randomized trials aimed to investigate the safety and BP lowering efficacy of a novel RDN method, with perivascular alcohol delivery using the Peregrine Kit.

Unusual Gastric Contrast Extravasation After Coronary Angiography

A 79-year-old woman presented with new-onset heart failure. She had pleural effusion, pericardial effusion, and an ejection fraction of 35% on echocardiogram. Her coronary angiogram revealed mild coronary artery disease (CAD). However, initially unexplained extravasation of the contrast was also seen in the cranial view during angiogram. The decision was made to medically manage CAD, but she remained tachycardic, with borderline low blood pressure. After a series of complications and tests, clearance of contrast from the stomach was confirmed. This represents an unusual case in which fluoroscopy revealed active gastric bleeding with contrast extravasation during coronary angiography.

Novel device-based therapies to improve outcome in ST-segment elevation myocardial infarction

Primary percutaneous coronary intervention (PPCI) has dramatically changed the outcome of patients with ST-elevation myocardial infarction (STEMI). However, despite improvements in interventional technology, registry data show little recent change in the prognosis of patients who survive STEMI, with a significant incidence of cardiogenic shock, heart failure, and cardiac death. Despite a technically successful PPCI procedure, a variable proportion of patients experience suboptimal myocardial reperfusion. Large infarct size and coronary microvascular injury, as the consequence of ischaemia-reperfusion injury and distal embolization of atherothrombotic debris, account for suboptimal long-term prognosis of STEMI patients. In order to address this unmet therapeutic need, a broad-range of device-based treatments has been developed. These device-based therapies can be categorized according to the pathophysiological pathways they target: (i) techniques to prevent distal atherothrombotic embolization, (ii) techniques to prevent or mitigate ischaemia/reperfusion injury, and (iii) techniques to enhance coronary microvascular function/integrity. This review is an overview of these novel technologies with a focus on their pathophysiological background, procedural details, available evidence, and with a critical perspective about their potential future implementation in the clinical care of STEMI patients.

Alcohol-Mediated Renal Sympathetic Neurolysis for the Treatment of Hypertension: The Peregrine™ Infusion Catheter

Renal sympathetic denervation using conventional non-irrigated radiofrequency catheters has potential technical shortcomings, including limited penetration depth and incomplete circumferential nerve damage, potentially impacting therapeutic efficacy. Against this background, second generation multi-electrode, radiofrequency and ultrasound renal denervation systems have been developed to provide more consistent circumferential nerve ablation. Irrigated catheters may allow deeper penetration while minimizing arterial injury. In this context, catheter-based chemical denervation, with selective infusion of alcohol, a potent neurolytic agent, into the perivascular space, may minimize endothelial, intimal and medial injury while providing circumferential neurolysis. Animal studies demonstrate pronounced renal norepinephrine level reductions and consistent renal nerve injury after perivascular alcohol infusion using the Peregrine Catheter. Early clinical studies demonstrated significant blood pressure reductions and a reasonable safety profile. Randomized sham-controlled trials (NCT03503773, NCT02910414) are underway to examine whether the aforementioned theoretical advantages of alcohol-medicated denervation with the Peregrine System™ Kit translate into clinical benefits.

Integrated Stent Delivery System: A Next Generation of Stent Delivery and Drug-Eluting Stent

The SLENDER Integrated Delivery System (IDS™) is an 'all-in-one' fixed-wire coronary stenting device designed for direct stenting, precluding the need for conventional guidewires and predilatation balloons. It achieves ultra-low profiles (crossing profiles as low as 0.029″/0.737 mm), enabling the downsizing of catheters to facilitate transradial intervention in a large subsets of patients. The IDS represents the first advance in coronary stent delivery since the introduction of rapid-exchange stent delivery systems >20 years ago. SLENDER IDS has demonstrated non-inferiority compared with commercial DES, excellent long-term safety and a potentially more efficient approach to PCI where patient comfort is enhanced, procedures are streamlined, and resource consumption is reduced. This paper will summarize the novel features of this new stent delivery system and the early clinical data demonstrating safety and efficacy.

Next generation renal denervation: chemical "perivascular" renal denervation with alcohol using a novel drug infusion catheter

BACKGROUND/PURPOSE

We update the pre-clinical and early clinical results using a novel endovascular approach, to perform chemical renal denervation, via peri-adventitial injection of micro-doses of dehydrated alcohol (ethanol-EtOH).

METHODS/MATERIALS

A novel, three-needle delivery device (Peregrine™) was used to denervate the renal arteries of adult swine (n = 17) and in a first-in-man feasibility study (n = 18). In the pre-clinical testing EtOH was infused bilaterally with one infusion per renal artery into to the perivascular space, using EtOH doses of 0.3 ml/artery (n = 8), and 0.6 ml/artery (n = 9), and with saline sham control (0.4 ml/artery n = 3). Renal parenchymal norepinephrine (NE) concentration (performed blindly), and safety were the primary endpoints. Data from the first-in-man study (n = 18) to evaluate device performance, safety and peri-procedural pain are reported.

RESULTS

In the pre-clinical testing renal function was unchanged at 3-month follow-up. Angiography at 90 days (n = 34 arteries) demonstrated normal appearing renal arteries, unchanged from baseline, and without stenosis or other abnormalities. The reductions in mean renal parenchymal NE reductions at 3 months were 68% and 88% at doses of 0.3 and 0.6 ml, respectively (p < 0.001 vs. controls). In the first-in-man study, there was 100% device success, no complications, a mean treatment time of 4.3 ± 3 minutes/artery, and minimal or no patient discomfort during treatment. Angiography at 6-months showed no evidence of renal artery stenosis, and evidence of a reduction of blood pressure from baseline.

CONCLUSION

Perivascular RDN using micro-doses of alcohol is a promising alternative to energy-based systems to achieve dose-dependent, predictable, safe and essentially painless renal denervation. Further clinical evaluation is warranted.

SUMMARY

(For annotated table of contents) This paper describes the preclinical results, in a porcine model, and the early first-in-man results, using the Peregrine™ chemical renal denervation catheter to perform renal sympathetic denervation using micro-doses of alcohol.

Rationale and design of the AngeLmed for Early Recognition and Treatment of STEMI trial: a randomized, prospective clinical investigation

Significant improvements in door-to-balloon times have led to a reduction in mortality in ST-segment elevation myocardial infarction; however, mean symptom-to-door times remain at 2 to 3 hours. An intracardiac electrogram monitoring device may be beneficial in high-risk patients by alerting them to rapidly progressive ST-segment changes indicative of acute coronary occlusion. The Cardiosaver and DETECT phase I clinical studies demonstrated the safety, feasibility, and potential benefit of using an intracardiac electrogram monitoring device to alert the patient to seek medical attention. The goal of the randomized, prospective ALERTS Trial (Clinicaltrials.gov no. NCT00781118) is to evaluate the efficacy of an implantable monitoring device (IMD) in reducing the composite of either cardiac or unexplained death, new Q-wave myocardial infarction, or symptom-to-door time of >2 hours for confirmed thrombotic events. The IMD alerts the patient in real time when ST-segment deviation from a personalized baseline exceeds the trigger threshold. The trial is designed to enroll high-risk post-acute coronary syndrome patients or patients with previous multivessel coronary artery bypass surgery. All patients have the IMD implanted, with 1:1 unblinded randomization to the alerting feature being either turned on versus turned off for the first 6 months. Randomization occurs at the first follow-up visit, 7 to 14 days after the implantation of the IMD. Subjects then return for follow-up visits at months 1, 3, and 6 and thereafter every 6 months until closure of the investigational device exemption. Subjects who cannot be implanted successfully or who have the device explanted are removed from the study and followed up for a minimum of 30 days post-procedure. If a subject experiences a device-related complication and/or adverse experience, the subject is followed up until resolution or until the condition becomes stable and no further change is anticipated.

Ethanol-mediated perivascular renal sympathetic denervation: preclinical validation of safety and efficacy in a porcine model

AIMS

We report the use of a novel endovascular approach using chemical neurolysis, via periadventitial injection of dehydrated ethanol (EtOH) to perform renal artery denervation.

METHODS AND RESULTS

A novel, three-needle delivery device was introduced into the renal arteries of adult swine using fluoroscopic guidance. EtOH was injected bilaterally with one injection per artery, via the three needles into the adventitial and periadventitial space, using EtOH doses 0.15 ml/artery; n=3, 0.30 ml/artery; n=3, and 0.60 ml/artery; n=3, with saline injection as a sham control (0.4 ml/artery; n=3), and naive subjects (n=7) as a true negative control. The renal parenchymal norepinephrine (NE) concentration at two-week follow-up was the primary efficacy endpoint. The mean renal NE reduction was 54%, 78% and 88% at doses of 0.15 ml, 0.30 ml and 0.60 ml, respectively (p<0.0001 vs. controls). Histological examination revealed marked, and deep, circumferential renal nerve injury at depths of 2-8 mm from the intimal surface. There was no evidence of device-related or EtOH-induced injury to the intimal layers. In some samples at the higher EtOH doses, there was focal loss of smooth muscle cells in the outer media. Angiography at 45 days demonstrated normal appearing renal arteries with no detectable stenoses (n=8).

CONCLUSIONS

Circumferential adventitial delivery of very low doses of EtOH may be a promising alternative to energy-based systems to achieve dose-dependent, and predictable renal denervation. Further study is warranted.

A statistically based acute ischemia detection algorithm suitable for an implantable device

This study investigates the performance of a new statistically driven acute ischemia detection algorithm that can process data from two bipolar cutaneous or subcutaneous leads. During a start-up phase, the algorithm processes electrocardiogram signals to determine a normal range of ST-segment deviation as a function of heart rate. The algorithm then generates upper and lower ST-deviation thresholds based on the dispersion of the baseline ST-deviation data. After the start-up phase, persistent ST-deviation that is beyond either the upper or lower thresholds results in detection of acute ischemia. To test the algorithm, we performed long-term (10 day) Holter monitoring in a control group of 14 subjects. We also performed Holter monitoring during balloon angioplasty, and for 2 days after surgery, in 30 subjects who underwent elective percutaneous coronary interventions ("PCI"). We determined the percentage of balloon inflations the algorithm detected without producing false positive detections within the control group 10-day daily life data. The algorithm detected 17/17 LAD occlusions, 7/8 LCX occlusions, and 8/9 RCA occlusions. Our results suggest that automatically generated, subject-specific, heart-rate dependent ST-deviation thresholds can detect PCI induced myocardial ischemia without resulting in false positive detections in a small control group.

High incidence of inaccurate stent placement in the treatment of coronary aorto-ostial disease

OBJECTIVES

The purpose of this study was to evaluate the incidence of inaccurate stent positioning in the treatment of coronary aorto-ostial lesions.

BACKGROUND

The percutaneous treatment of aorto-ostial disease is challenging, with a paucity of data describing the incidence of stent mispositioning.

METHODS

We retrospectively reviewed the accuracy of stent positioning in 100 consecutive coronary aorto-ostial lesions. Using careful angiographic review, each stent placement was classified as "missed" (> 1 mm distal or proximal to the angiographically determined ostium) or "accurately" positioned.

RESULTS

The true ostium was missed during stent placement in 54% of cases. In 52% of the misses, the stent was placed too proximally. This proximal miss was associated with an inability to coaxially re-engage the treated vessel in 93% of the cases. The stent was placed too distally in 48% of missed cases, resulting in a placement of one or more additional overlapping stents in 38% of those cases. Clinical follow-up (mean, 24.5 ± 12.9 months) was obtained in 98% of cases. Angiographic follow-up prompted by recurrent chest pain or ischemia was performed in 45/100 cases. There was a three-fold increase in restenosis and target lesion revascularization (TLR) among the cohort of patients with stent misplacement (26% and 23%, respectively) compared to those with accurate stent placement (9% and 6%, respectively; p = 0.02 for both restenosis and TLR).

CONCLUSIONS

Angiographically-guided stenting for coronary aorto-ostial disease leads to a high incidence of proximal and distal stent misplacement. Stent mispositioning is associated with significantly higher restenosis and clinically driven TLR compared to patients with accurate stent placement.

Evaluation of balloon withdrawal forces with bare-metal stents, compared with Taxus and Cypher drug-eluting coronary stents: balloon, stent and polymer interactions

BACKGROUND

There have been reports of serious complications related to difficulty removing the deflated Taxus stent delivery balloon after stent deployment. The purpose of this study was to determine whether the Taxus SIBS polymer was "sticky" and associated with an increase in the force required to remove the stent delivery balloon after stent deployment, using a quantitative, ex-vivo model.

METHODS

Balloon-polymer-stent interactions during balloon withdrawal were measured with the Taxus Liberté, Liberté bare-metal stent (BMS; no polymer = control), the Cordis Cypher drug-eluting stent (DES; PEVA/PBMA polymer) and the BX Velocity (no polymer). We quantitatively measured the force required to remove the deflated stent delivery balloon from each of these stents in simulated vessels at 37 degrees C in a water bath. Balloon withdrawal forces were measured in straight (0 degree curve), mildly curved (20 degree curve) and moderately curved (40 degree curve) simulated vessel segments.

RESULTS

The average peak force required to remove the deflated balloon catheter from the Taxus Liberté DES, the Liberté BMS, the Cypher DES, and the Bx Velocity BMS were similar in straight segments, but were much greater for the Taxus Liberté in the moderately curved segments (1.4 lbs vs. 0.11 lbs, 0.11 lbs and 0.12 lbs, respectively; p < 0.0001).

CONCLUSION

The SIBS polymer of the Taxus Liberté DES appears to be "sticky" and is associated with high forces required to withdraw the deflated balloon from the deployed stent in curved segments. This withdrawal issue may help to explain the clinical complications that have been reported with this device.

A New Fixed-wire, ‘Stent-on-a-wire’, Very-low-profile Stent Delivery System – Rationale, Design and Update

Coronary artery stenting has evolved substantially since the first use of coronary stenting as an adjunct to balloon angioplasty in the early 1990s. The performance (and particularly the deliverability) of coronary stents has improved such that coronary stenting is now the primary mode of revascularisation for percutaneous coronary interventions (PCIs) in more than 95% of cases. The new Svelte™ stent-on-a-wire (SOAW) delivery system represents one of the first substantive innovations in stent delivery systems (SDS) in more than a decade. This SDS uses a shapeable ‘fixed wire’ as an integral part of the SDS. This allows a significant reduction in SDS profile (~0.029 inches) compared with conventional monorail or over-the-wire SDS. This SOAW SDS is intended to facilitate direct stenting. It has the potential to provide substantial procedural cost savings by eliminating the need for a coronary guidewire and balloon pre-dilatation and/or post-dilatation, and by reducing contrast use and the time required to complete the procedure. The SOAW system is compatible with 5Fr guiding catheters, and may reduce the need for closure devices, facilitate stenting via the radial approach and (potentially) reduce bleeding risks. In conclusion, the Svelte SOAW SDS represents a new very-low-profile balloon-expandable SDS that should promote direct stenting in PCIs. The efficiency and small profile of this SDS may allow procedural cost savings, a reduction in procedure time and a reduced risk of bleeding complications. These theoretical advantages will need to be demonstrated in clinical trials.

Initial clinical experience using an ostial stent positioning system (Ostial Pro) for the accurate placement of stents in the treatment of coronary aorto-ostial lesions

OBJECTIVE

To evaluate the safety and efficacy of a new nitinol stent positioning system to assist in the placement of aorto-ostial coronary stents.

BACKGROUND

The stenting of aorto-ostial lesions is technically challenging.

METHODS

We report the first clinical series using the Ostial Pro to assist in the precise placement of stents in coronary aorto-ostial lesions. These results were compared to matched cases performed without the ostial positioning system.

RESULTS

The Ostial Pro is a simple nitinol device with self-expanding legs that are advanced just distal to the tip of the guiding catheter. The nitinol legs prevent the entry of the guiding catheter into the target vessel and align the tip of the guiding catheter. Using the Ostial Pro positioning device, angiographic and clinical success was achieved in 30/30 (100%) cases. Excellent stent positioning was confirmed by angiography (n = 30) and intravascular ultrasound (n = 28). The final true ostial dimension was larger than the stented segment minimum luminal diameter in 30/30 cases. In a matched consecutive cohort of 30 consecutive coronary aorto-ostial stent cases placed without the Ostial Pro, we observed an ostial stent malpositioning in 18/30 (60%) of cases (p < 0.0001 vs. cases performed with Ostial Pro).

CONCLUSIONS

1) The Ostial Pro is a new FDA-cleared nitinol device that is simple to use and effective in allowing the precise placement of stent(s) at the aorto-ostial location; 2) this approach appears to provide an efficient means to assure accurate stent placement and minimal residual stenosis in these difficult-to-treat lesions.

Pharmaceutical interventions for the management of no-reflow

A common complication of percutaneous coronary intervention (PCI), no-reflow is predominantly encountered during interventions in degenerated saphenous vein grafts and is associated with a marked increase in short-term mortality risk. Etiologically, no-reflow is complex and multifactorial. Microembolic debris from dilated target sites, sustained diffuse microvascular spasm, and pathophysiologic alterations from initial ischemic insults and subsequent reperfusion injuries result in persistence of myocardial ischemia despite angiographic evidence of restored vessel patency. Treatments to prevent or reverse no-reflow include antiplatelet medications to interfere with platelet aggregation. However, insufficient evidence exists demonstrating benefits with their prophylactic use in humans. Distal protection devices target microemboli, but soluble vasoactive factors may elude capture, contributing to downstream vasospasm. Intracoronary administration of vasodilators during PCI address a root cause of no-reflow. Adenosine, nitroprusside, verapamil, nicardipine and others have been evaluated clinically, showing improvements across a range of surrogate TIMI flow grade and frame count and real endpoints (wall motion indices and elevated CPK). Nicardipine may be particularly well-suited for prevention or reversal of no-reflow, demonstrating pharmacologic protection equal or superior to mechanical distal protection devices. The consistent and often dramatic mitigation of no-reflow by adjunctive use of vasodilators supports the role of microvascular spasm as a major, modifiable cause of the syndrome and a critical therapeutic target. A further large-scale, prospective, randomized, controlled clinical study is warranted to confirm prior findings, determine the optimal dosing regimen, and whether treatment or prevention of no-reflow confers clinically relevant outcome benefits.

Late DES thrombosis: A lot of smoke, very little fire?

Recent studies and editorials have stirred controversy and generated tremendous publicity in the lay press related to the safety of drug-eluting stents (DES) for the treatment of coronary artery disease. Questions have been raised regarding the risks of late, or very late stent thrombosis with DES. The purpose of this editorial and review of stent thrombosis is to illuminate some counterpoints to some of the attention surrounding the issues of late DES thrombosis. The risks of DES stent thrombosis versus BMS may have been overstated by flawed studies. Late stent thrombosis does occur with both BMS and DES, and may or may not be modestly higher with DES. The time course of very late "DES thrombosis," suggests that persistent plaque ruptures and disease progression in the target vessel may cause some, or many of these events. There is still much to be learned about the biology of DES. Although there is a small risk of late thrombosis with DES, there is little question that this technology provides benefit to the vast majority of patients compared with prior revascularization strategies, using balloon angioplasty, BMS, or bypass surgery. Substantial resources should be devoted to creating more biocompatible DES systems, and to minimizing the risks of both early and late stent thrombosis.

"Pharmacologic" distal protection using prophylactic, intragraft nicardipine to prevent no-reflow and non-Q-wave myocardial infarction during elective saphenous vein graft intervention

BACKGROUND

Coronary saphenous vein bypass graft (SVG) stenting has been associated with up to a 30% rate of no-reflow or myocardial infarction (MI) when performed without distal protection.

METHODS

We evaluated the technique using prophylactic pharmacologic arteriolar vasodilatation with intracoronary nicardipine followed by immediate direct stenting for the treatment of degenerated coronary SVGs without mechanical distal protection. Data were collected from 83 consecutive elective SVG interventions in 68 patients. Quantitative coronary angiographic measurements were performed by the Borgess angiographic core lab. Electrocardiograms (ECGs), CPKs, and CPK-MBs were obtained preprocedure and at 12 to 18 hours after the intervention. Follow-up data at 30 days were obtained in 67/68 (98%) patients.

RESULTS

The average graft age was 11.9 +/- 6.6 years with thrombus in 26/83 vessels (31%). The primary adverse endpoint of total CPK >3 times the upper limit of normal (ULN), or CPK-MB >3 times the ULN were seen in 1/68 (1.5%) and 3/68 (4.4%) patients, respectively. No-/slow-reflow was observed transiently in 2/83 SVG interventions (2.4%). Of the patients, 1/68 had persistent, minor ECG changes after stenting (1.4%). No patient had a Q-wave MI. Inhospital major adverse cardiac events (MACE) (death, MI, repeat TLR) were observed in only 3/68 patients (CPK-MB elevation). There were no additional MACE events (0/68) from hospital discharge to 30 days.

CONCLUSIONS

(1) Prophylactic vasodilatation with intragraft nicardipine followed by direct stenting appears to be a safe and effective means of performing elective SVG revascularization; (2) this approach may provide a simple and time- and cost-effective alternative or adjunct to mechanical distal protection for elective SVG interventions.

The SIRIUS-DIRECT trial: A multi-center study of direct stenting using the sirolimus-eluting stent in patients with de novo native coronary artery lesions

OBJECTIVE

To assess the safety and efficacy of direct stenting using the sirolimus-eluting BX Velocitytrade mark stent in patients with coronary lesions.

BACKGROUND

Although direct coronary stenting has become a widespread practice, there have been no systematic assessments of direct stenting with drug-eluting stents.

METHODS

Total of 225 patients with identical inclusion and exclusion criteria as the original SIRIUS trial were enrolled in this prospective single-arm study. They were compared in a no-inferiority design with 412 similar patients from the SIRIUS trial who had sirolimus-eluting stents deployed after predilatation and were preassigned to angiographic follow-up evaluation.

RESULTS

Direct stenting was successful in 85.8% of the patients. Compared with the predilatation group, direct stenting was associated with shorter median procedure duration (33 min vs. 45 min, P < 0.001). Angiographic follow-up at 8 months revealed similar late loss (in-stent-0.19 +/- 0.47 mm vs. 0.17 +/- 0.44 mm, and in-lesion-0.23 +/- 0.41 mm vs. 0.24 +/- 0.47 mm) and similar frequency of binary restenosis (in-stent-4.6% vs. 3.2% and in-lesion-6.1% vs. 8.9%) between the two treatment strategies. However, stent-edge restenosis was lower with direct stenting than in the predilatation control group (2.1% vs. 6.9%, P = 0.02). At 12-months, there were no significant differences in target lesion revascularization (3.7% vs. 5.1%, P = ns) or composite major adverse cardiac events (7.0% vs. 8.3%, P = ns).

CONCLUSIONS

In patients similar to those treated in the SIRIUS trial, direct stenting using sirolimus-eluting stents achieves excellent short- and long-term clinical and angiographic results with shorter procedure time and less frequent stent edge restenosis compared with predilation stent implantation techniques.

Real-Time Detection and Alerting for Acute ST-Segment Elevation Myocardial Ischemia Using an Implantable, High-Fidelity, Intracardiac Electrogram Monitoring System With Long-Range Telemetry in an Ambulatory Porcine Model

OBJECTIVES

The purpose of this study was to evaluate feasibility of using real-time, high-fidelity, intracardiac electrogram monitoring from a permanently implantable ischemia detection system (IIDS), with long-range telemetry capability to detect ST-segment shifts associated with acute or subacute coronary occlusion in a porcine model.

BACKGROUND

Early identification of coronary occlusion with ST-segment elevation could profoundly accelerate the timing of revascularization and improve clinical outcomes.

METHODS

This paper reports the first investigation using real-time, high-fidelity, intracardiac electrogram monitoring from a permanently IIDS, with long-range telemetry capability. This IIDS was tested in an ambulatory porcine model, with acute coronary occlusion precipitated by stent thrombosis. Two overlapping copper stents were implanted in the left anterior descending (n = 3), the circumflex (n = 3), or the right coronary artery (n = 2) of juvenile farm pigs. Monitoring was carried using telemetry from the IIDS.

RESULTS

All stented pigs had acute ST-segment elevation event(s) triggering the alerting thresholds of the IIDS. All triggered events were confirmed to be caused by thrombosis of the copper stent(s), and well correlated to infarct age and location. Four of the 8 pigs died from ventricular fibrillation, recorded by the IIDS at a mean time of 70 +/- 121 h after ST-segment alert. The sensitivity and specificity of alerting for ST-segment shift, associated with thrombotic coronary occlusion, were 100% and 100%, respectively.

CONCLUSIONS

This study demonstrates the ability of an implantable ischemia detection system to detect ST-segment elevation from coronary occlusion in a porcine model of ST-segment elevation myocardial infarction. ST-segment elevation was sufficient to trigger alerting thresholds in all 3 epicardial coronary distributions. Such a system, with real-time alerting capability, could advance the time frame of reperfusion therapy and potentially prevent, rather than interrupt, acute myocardial infarction in patients with coronary artery disease.

High-dose, single-bolus eptifibatide: a safe and cost-effective alternative to conventional glycoprotein IIb/IIIa inhibitor use for elective coronary interventions

BACKGROUND

Adjunctive pharmacotherapy with eptifibatide, a glycoprotein (GP) IIb/IIIa inhibitor, as an intravenous bolus followed by infusion has been shown to improve outcomes in elective coronary interventions (PCI). However, bleeding complications and costs have limited the routine adoption of this regimen.

PURPOSE

The goal of this study was to examine the safety, efficacy and cost-effectiveness of high-dose, single-bolus eptifibatide, without post-intervention infusion, in "real-world" patients undergoing elective PCI.

METHODS

We studied 401 patients with stable and unstable angina who were treated with a high-dose (20 mg), single bolus of eptifibatide plus heparin prior to the start of elective PCI. Exclusion criteria included recent MI, stenting of bypass graft(s), rotational atherectomy and/or brachytherapy. The primary study endpoints were major adverse clinical events (MACE), defined as the in-hospital and 30-day incidence of death from any cause, Q-wave or non-Q-wave MI, repeat target vessel revascularization and/or major bleeding complications.

RESULTS

Relevant demographic and procedural characteristics included mean age: 66.4 +/- 11.2; male gender: 242/401 (61%); number of vessels treated per patient: 1.46 +/- 0.42; and number of stents deployed per patient: 1.82 +/- 0.65. In-hospital non-Q-wave MI (CPK and/or CPK-MB > 3 times the upper limit of normal) occurred in 7/401 patients (1.75%) and MACE was 2.25%. Major bleeding complications were seen in 2/401 patients (0.49%). There were 4 additional MACE events at 30-day follow up (total MACE and bleeding = 3.25%). The average anticoagulation cost was 66 dollars/patient.

CONCLUSIONS

Intravenous eptifibatide, administered as a high-dose (20 mg) single-vial bolus, is a safe, effective and highly cost-effective alternative to the conventional regimens of bolus plus prolonged intravenous GP IIb/IIIa inhibitor infusion for patients undergoing elective PCI.

Coronary artery rupture during balloon angioplasty, rescued with localized thrombin injection and coil embolization

Distal intracoronary thrombin injection has been used successfully to seal very small, guidewire related, coronary artery perforations during percutaneous coronary intervention. This case report expands upon this therapeutic approach, by describing the use of high dose distal thrombin injection for the successful (non-surgical) management of balloon-induced coronary artery rupture, with an intrapericardial leak.

Impact of frame selection on quantitative coronary angiographic analysis after coronary stenting

This study examined the impact of frame selection on the results of quantitative coronary angiographic analysis (QCA). Thirty-nine patients who had stent implantation and a follow-up angiogram 5-7 months later were studied using the CMS Medis QCA system. The acute and follow-up films (n = 39) were read in three different ways to assess the impact of frame selection: frame chosen making the stent appear least narrowed (best); frame chosen making the stent appear most narrowed (worst); and measurement from the mean value from three consecutive end-diastolic frames (core). We measured the mean percent diameter stenosis immediately postintervention and at follow-up, the binary restenosis rate, and the late lumen loss (mm). There was a statistically significant difference in all of these variables when comparing the three methods of frame selection (best vs. worst, P values < 0.001; best or worst vs. core, P values < 0.01). This study demonstrates a marked variability in the results obtained using QCA to measure the acute and late coronary stent outcomes when operators have the ability to select which frame to analyze (frame bias).