Paclitaxel-Coated Balloon vs Uncoated Balloon for Coronary In-Stent Restenosis: The AGENT IDE Randomized Clinical Trial

Importance

Drug-coated balloons offer a potentially beneficial treatment strategy for the management of coronary in-stent restenosis. However, none have been previously evaluated or approved for use in coronary circulation in the United States.

Objective

To evaluate whether a paclitaxel-coated balloon is superior to an uncoated balloon in patients with in-stent restenosis undergoing percutaneous coronary intervention.

Design, Setting, and Participants

AGENT IDE, a multicenter randomized clinical trial, enrolled 600 patients with in-stent restenosis (lesion length <26 mm and reference vessel diameter >2.0 mm to ≤4.0 mm) at 40 centers across the United States between May 2021 and August 2022. One-year clinical follow-up was completed on October 2, 2023.

Interventions

Participants were randomized in a 2:1 allocation to undergo treatment with a paclitaxel-coated (n = 406) or an uncoated (n = 194) balloon.

Main Outcomes and Measures

The primary end point of 1-year target lesion failure-defined as the composite of ischemia-driven target lesion revascularization, target vessel-related myocardial infarction, or cardiac death-was tested for superiority.

Results

Among 600 randomized patients (mean age, 68 years; 157 females [26.2%]; 42 Black [7%], 35 Hispanic [6%] individuals), 574 (95.7%) completed 1-year follow-up. The primary end point at 1 year occurred in 17.9% in the paclitaxel-coated balloon group vs 28.6% in the uncoated balloon group, meeting the criteria for superiority (hazard ratio [HR], 0.59 [95% CI, 0.42-0.84]; 2-sided P = .003). Target lesion revascularization (13.0% vs 24.7%; HR, 0.50 [95% CI, 0.34-0.74]; P = .001) and target vessel-related myocardial infarction (5.8% vs 11.1%; HR, 0.51 [95% CI, 0.28-0.92]; P = .02) occurred less frequently among patients treated with paclitaxel-coated balloon. The rate of cardiac death was 2.9% vs 1.6% (HR, 1.75 [95% CI, 0.49-6.28]; P = .38) in the coated vs uncoated balloon groups, respectively.

Conclusions and Relevance

Among patients undergoing coronary angioplasty for in-stent restenosis, a paclitaxel-coated balloon was superior to an uncoated balloon with respect to the composite end point of target lesion failure. Paclitaxel-coated balloons are an effective treatment option for patients with coronary in-stent restenosis.

Trial Registration

ClinicalTrials.gov Identifier: NCT04647253.

Long term recovery of right ventricular function after treatment of intermediate and high risk pulmonary emboli

INTRODUCTION

Pulmonary embolism (PE) is a common and significant source of mortality and morbidity worldwide. A subset of patients with PE, particularly those who have intermediate and high risk events, are at increased risk for long-term right ventricular (RV) dysfunction; however, the impact of novel advanced therapies used for acute PE, including catheter-directed intervention, on long-term RV function remains uncertain. We sought to determine whether use of advanced therapies (catheter-directed intervention or systemic thrombolysis) is associated with improved long-term RV function.

MATERIALS AND METHODS

Retrospective, single-center cohort study of adult (≥18 year old) patients admitted and discharged alive with a diagnosis of acute PE, who fell under the category of intermediate or high risk, with available follow-up echocardiograms at least 6 months after the index, seen at a single quaternary referral center in Los Angeles, CA between 2012 and 2021.

RESULTS

There were 113 patients in this study (58 (51.3 %) treated with anticoagulation alone, 12 (10.6 %) treated with systemic thrombolysis, and 43 (38.1 %) treated with catheter-directed intervention), with approximately equal gender and racial distribution. Patients treated with advanced therapies were significantly more likely to have moderate-severe RV dysfunction (100 % for those treated with thrombolysis, 88.3 % for those treated with catheter-directed intervention, vs 55.2 % for those treated with anticoagulation alone; p < 0.001). At a follow-up of about 1.5 years, patients treated with advanced therapy (systemic thrombolysis or catheter-directed intervention) were more likely to have normalization of RV function (93-100 % vs 81 % for anticoagulation alone, p = 0.04). The subgroup of patients with intermediate-risk PE was significantly more likely to have normalization of RV function (95.6 % vs 80.4 % for anticoagulation alone, p = 0.03). Use of advanced therapy was not associated with substantial short-term adverse events among patients who survived to hospital discharge.

CONCLUSION

Patients with intermediate and high risk PE were more likely to have recovery in RV function long-term if treated with catheter-directed intervention or systemic thrombolysis, as compared to anticoagulation alone, without substantial safety issues, despite having worse RV function at baseline. Further data is needed to verify this observation.

Sustained Mechanical Aspiration Thrombectomy for High Thrombus Burden Coronary Vessel Occlusion: The Multicenter CHEETAH Study

BACKGROUND

Poor myocardial reperfusion due to distal embolization and microvascular obstruction after percutaneous coronary intervention is associated with increased risk of morbidity and mortality. Prior trials have not shown a clear benefit of routine manual aspiration thrombectomy. Sustained mechanical aspiration may mitigate this risk and improve outcomes. The objective of this study is to evaluate sustained mechanical aspiration thrombectomy before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients.

METHODS

This prospective study evaluated the Indigo CAT RX Aspiration System (Penumbra Inc, Alameda CA) for sustained mechanical aspiration thrombectomy before percutaneous coronary intervention at 25 hospitals across the USA. Adults presenting within 12 hours of symptom onset with high thrombus burden and target lesion(s) located in a native coronary artery were eligible. The primary end point was a composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or new or worsening New York Heart Association class IV heart failure within 30 days. Secondary end points included Thrombolysis in Myocardial Infarction thrombus grade, Thrombolysis in Myocardial Infarction flow, myocardial blush grade, stroke, and device-related serious adverse events.

RESULTS

From August 2019 through December 2020, a total of 400 patients were enrolled (mean age 60.4 years, 76.25% male). The primary composite end point rate was 3.60% (14/389 [95% CI, 2.0-6.0%]). Rate of stroke within 30 days was 0.77%. Final rates of Thrombolysis in Myocardial Infarction thrombus grade 0, Thrombolysis in Myocardial Infarction flow 3, and myocardial blush grade 3 were 99.50%, 97.50%, and 99.75%, respectively. No device-related serious adverse events occurred.

CONCLUSIONS

Sustained mechanical aspiration before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients was safe and was associated with high rates of thrombus removal, flow restoration, and normal myocardial perfusion on final angiography.

Continuous mechanical aspiration thrombectomy performs equally well in main versus branch pulmonary emboli: A subgroup analysis of the EXTRACT-PE trial

INTRODUCTION

The EXTRACT-PE trial evaluated the safety and performance of the Indigo Aspiration System (Penumbra Inc.) with an 8F continuous mechanical aspiration thrombectomy system for the treatment of pulmonary embolism (PE). This subgroup analysis evaluates performance outcomes of patients with main pulmonary artery (PA) emboli versus discrete unilateral or bilateral PA emboli without main PA involvement.

METHODS

The EXTRACT-PE trial was a prospective, single-arm, multicenter trial that enrolled 119 patients with acute submassive PE. Emboli location was collected at the time of enrollment, CT obstruction was measured and assessed by a Core Lab, and patients were grouped on whether emboli involved the main PA (with or without branch vessels) or not (branch vessels alone). Procedural device time, changes in the right ventricle to left ventricle (RV/LV) ratio, and systolic PA pressure from pre-and posttreatment were compared between the two groups.

RESULTS

Out of the 119 patients enrolled, 118 had core lab-assessed clot locations. Forty-five (38.1%) had emboli that involved the main PA and 73 (61.9%) had only branch emboli. No significant difference was observed between these groups for 30-day mortality, procedural device time, changes in RV/LV ratio, reduction in CT Obstruction Index, or for systolic PA pressure from pre-and posttreatment. The mean absolute reduction in clot burden was significant in both groups.

CONCLUSION

Continuous mechanical aspiration thrombectomy with the 8F Indigo Aspiration System was effective at improving clinical outcomes for submassive PE patients regardless of emboli location, and clot burden was significantly reduced in both groups.

Effects of Renal Denervation vs Sham in Resistant Hypertension After Medication Escalation: Prespecified Analysis at 6 Months of the RADIANCE-HTN TRIO Randomized Clinical Trial

Importance

Although early trials of endovascular renal denervation (RDN) for patients with resistant hypertension (RHTN) reported inconsistent results, ultrasound RDN (uRDN) was found to decrease blood pressure (BP) vs sham at 2 months in patients with RHTN taking stable background medications in the Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN TRIO) trial.

Objectives

To report the prespecified analysis of the persistence of the BP effects and safety of uRDN vs sham at 6 months in conjunction with escalating antihypertensive medications.

Design, Setting, and Participants

This randomized, sham-controlled, clinical trial with outcome assessors and patients blinded to treatment assignment, enrolled patients from March 11, 2016, to March 13, 2020. This was an international, multicenter study conducted in the US and Europe. Participants with daytime ambulatory BP of 135/85 mm Hg or higher after 4 weeks of single-pill triple-combination treatment (angiotensin-receptor blocker, calcium channel blocker, and thiazide diuretic) with estimated glomerular filtration rate (eGFR) of 40 mL/min/1.73 m2 or greater were randomly assigned to uRDN or sham with medications unchanged through 2 months. From 2 to 5 months, if monthly home BP was 135/85 mm Hg or higher, standardized stepped-care antihypertensive treatment starting with aldosterone antagonists was initiated under blinding to treatment assignment.

Interventions

uRDN vs sham procedure in conjunction with added medications to target BP control.

Main Outcomes and Measures

Six-month change in medications, change in daytime ambulatory systolic BP, change in home systolic BP adjusted for baseline BP and medications, and safety.

Results

A total of 65 of 69 participants in the uRDN group and 64 of 67 participants in the sham group (mean [SD] age, 52.4 [8.3] years; 104 male [80.6%]) with a mean (SD) eGFR of 81.5 (22.8) mL/min/1.73 m2 had 6-month daytime ambulatory BP measurements. Fewer medications were added in the uRDN group (mean [SD], 0.7 [1.0] medications) vs sham (mean [SD], 1.1 [1.1] medications; P = .045) and fewer patients in the uRDN group received aldosterone antagonists at 6 months (26 of 65 [40.0%] vs 39 of 64 [60.9%]; P = .02). Despite less intensive standardized stepped-care antihypertensive treatment, mean (SD) daytime ambulatory BP at 6 months was 138.3 (15.1) mm Hg with uRDN vs 139.0 (14.3) mm Hg with sham (additional decreases of -2.4 [16.6] vs -7.0 [16.7] mm Hg from month 2, respectively), whereas home SBP was lowered to a greater extent with uRDN by 4.3 mm Hg (95% CI, 0.5-8.1 mm Hg; P = .03) in a mixed model adjusting for baseline and number of medications. Adverse events were infrequent and similar between groups.

Conclusions and Relevance

In this study, in patients with RHTN initially randomly assigned to uRDN or a sham procedure and who had persistent elevation of BP at 2 months after the procedure, standardized stepped-care antihypertensive treatment escalation resulted in similar BP reduction in both groups at 6 months, with fewer additional medications required in the uRDN group.

Trial Registration

ClinicalTrials.gov Identifier: NCT02649426.

Renal artery variations in patients with mild-to-moderate hypertension from the RADIANCE-HTN SOLO trial

PURPOSE

To assess the variability of renal artery (RA) anatomy and presence of RA-pathology in patients with mild-to-moderate hypertension enrolled in the RADIANCE-HTN SOLO trial.

BACKGROUND

RADIANCE-HTN SOLO was a multicenter, international, blinded, randomized, sham-controlled trial evaluating ultrasound-based endovascular renal denervation (RDN) in patients with mild-to-moderate hypertension while off antihypertensive medications.

METHODS

Eligible subjects had pre-randomization renal CT- or MR- angiography (CTA, MRA) to confirm anatomic suitability and to define RA ablation sites. All images were sent for independent review for evaluation of RA anatomy and other vascular pathology.

RESULTS

A total of 324 patients underwent RA imaging (282 CTA and 42 MRA). Of those, 178 had simple anatomy with a single left and single right RA with mean diameters of 5.4 ± 0.9 and 5.1 ± 0.8 mm and mean lengths of 40.0 ± 12.9 and 52.0 ± 13.1 mm, respectively. Twenty-seven patients (8.3%) had unilateral or bilateral dual RAs with mean diameters of 4.0 ± 0.9 mm on the left and 3.9 ± 0.9 mm on the right. Forty percent (129/324) of patients had at least 1 accessory RA, with mean accessory diameters of 2.4 ± 0.8 mm on the left and 2.3 ± 0.8 mm on the right. Twenty-eight patients (8.6%) had at least 1 short (<25 mm) main RA. Incidental findings included: 9 patients (2.8%) with atherosclerotic RA stenosis ≥30%, 9 patients (2.8%) with fibromuscular dysplasia of RA and 2 patients (0.6%) with kidney and adrenal gland tumors.

CONCLUSIONS

Pre-procedure CTA or MRA imaging is a valuable aid in assessing RA anatomy prior to RDN because of variable RA anatomy. CTA or MRA may detect RA lesions, and renal or adrenal tumors which may need additional workup prior to consideration of RDN.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02649426.

Six-Month Results of Treatment-Blinded Medication Titration for Hypertension Control After Randomization to Endovascular Ultrasound Renal Denervation or a Sham Procedure in the RADIANCE-HTN SOLO Trial

BACKGROUND

The multicenter, international, randomized, blinded, sham-controlled RADIANCE-HTN SOLO trial (A Study of the ReCor Medical Paradise System in Clinical Hypertension) demonstrated a 6.3 mm Hg greater reduction in daytime ambulatory systolic blood pressure (BP) at 2 months by endovascular ultrasound renal denervation (RDN) compared with a sham procedure among patients not treated with antihypertensive medications. We report 6-month results after the addition of a recommended standardized stepped-care antihypertensive treatment to the randomized endovascular procedure under continued blinding to initial treatment.

METHODS

Patients with a daytime ambulatory BP ≥135/85 mm Hg and <170/105 mm Hg after a 4-week discontinuation of up to 2 antihypertensive medications, and a suitable renal artery anatomy, were randomized to RDN (n=74) or sham (n=72). Patients were to remain off antihypertensive medications throughout the first 2 months of follow-up unless safety BP criteria were exceeded. Between 2 and 5 months, if monthly measured home BP was ≥135/85 mm Hg, a standardized stepped-care antihypertensive treatment was recommended consisting of the sequential addition of amlodipine (5 mg/d), a standard dose of an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and hydrochlorothiazide (12.5 mg/d), followed by the sequential uptitration of hydrochlorothiazide (25 mg/d) and amlodipine (10 mg/d). Outcomes included the 6-month (1) change in daytime ambulatory systolic BP adjusted for medications and baseline systolic BP, (2) medication burden, and (3) safety.

RESULTS

A total of 69/74 RDN patients and 71/72 sham patients completed the 6-month ambulatory BP measurement. At 6 months, 65.2% of patients in the RDN group were treated with the standardized stepped-care antihypertensive treatment versus 84.5% in the sham group (P=0.008), and the average number of antihypertensive medications and defined daily dose were less in the RDN group than in the sham group (0.9±0.9 versus 1.3±0.9, P=0.010 and 1.4±1.5 versus 2.0±1.8, P=0.018; respectively). Despite less intensive standardized stepped-care antihypertensive treatment, RDN reduced daytime ambulatory systolic BP to a greater extent than sham (-18.1±12.2 versus -15.6±13.2 mm Hg, respectively; difference adjusted for baseline BP and number of medications: -4.3 mm Hg, 95% confidence interval, -7.9 to -0.6, P=0.024). There were no major adverse events in either group through 6 months.

CONCLUSIONS

The BP-lowering effect of endovascular ultrasound RDN was maintained at 6 months with less prescribed antihypertensive medications compared with a sham control.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT02649426.

Optical coherence tomography guided carotid artery stent procedure: technique and potential applications

OBJECTIVES

To (1) present a guide on how to perform optical coherence tomography (OCT) in carotid artery stenting (CAS), to (2) highlight several instructive cases illustrating OCT-guidance as an interventional strategy, and to (3) present the largest case-series of OCT-guided CAS performed in North America, demonstrating its feasibility as an imaging modality in this setting.

BACKGROUND

OCT is an intravascular imaging method that captures images with an axial resolution 10 times higher than intravascular ultrasound. OCT has proven to be a useful modality in coronary angiography and may have similar applications in evaluating carotid atherosclerotic disease.

METHODS

We compared our experience in CAS utilizing OCT (40 patients) versus that of CAS without OCT guidance (52 patients).

RESULTS

No strokes or deaths occurred in either group postprocedurally or at 12 months. Fluoroscopy time was reduced in the OCT arm (14 ± 1 vs. 16 ± 1 min). Postprocedural creatinine levels were identical (1 ± 0 mg/dl, P = 0.96). Procedure time (96 ± 8 vs. 80 ± 3 min, P = 0.06) and contrast use (94 ± 4 vs. 83 ± 4 ml, P = 0.05) was slightly elevated in the OCT arm.

CONCLUSIONS

We established a standardized protocol to consistently obtain OCT images that helped guide interventional decision-making during CAS. OCT imaging in the carotids requires a higher contrast load and prolongs procedure time. However, it can be performed without significant increases in fluoroscopy time or negatively affecting renal function. There were no negative safety signals in this pilot study.

Lower Extremity Revascularization Using Optical Coherence Tomography-Guided Directional Atherectomy: Final Results of the EValuatIon of the PantheriS OptIcal COherence Tomography ImagiNg Atherectomy System for Use in the Peripheral Vasculature (VISION) Study

PURPOSE

To evaluate the safety and efficacy of a novel optical coherence tomography (OCT)-guided atherectomy catheter in treating patients with symptomatic femoropopliteal disease.

METHODS

The VISION trial ( ClinicalTrials.gov identifier NCT01937351) was a single-arm, multicenter, global investigational device exemption study enrolling 158 subjects (mean age 67.2±10.5 years; 87 men) across 20 participating sites. In this cohort, 198 lesions were treated with an average length of 53±40 mm using the Pantheris catheter alone or Pantheris + adjunctive therapy. The primary safety endpoint was the composite of major adverse events (MAEs) through 6 months (objective performance goal 43.2%). Technical success (primary efficacy outcome) was defined as the percent of target lesions with a residual diameter stenosis ≤50% after treatment with the Pantheris device alone (objective performance goal 87.0%). Procedural success was defined as reduction in stenosis to ≤30% after Pantheris ± adjunctive therapy. Tissue specimens retrieved from each treated lesion were histologically analyzed to evaluate the accuracy and precision of OCT image guidance.

RESULTS

The primary efficacy outcome was achieved in 192 (97.0%) of the 198 lesions treated with the Pantheris catheter. Across all lesions, mean diameter stenosis was reduced from 78.7%±15.1% at baseline to 30.3%±11.8% after Pantheris alone (p<0.001) and to 22.4%±9.9% after Pantheris ± adjunctive therapy (p<0.001). Of the 198 target lesions, 104 (52.5%) were treated with the Pantheris alone, 84 (42.4%) were treated with Pantheris + adjunctive angioplasty, and 10 (5.1%) with Pantheris + angioplasty + stenting. The composite MAE outcome through 6 months occurred in 25 (16.6%) of 151 subjects. There were no clinically significant perforations, 1 (0.5%) catheter-related dissection, 4 (2%) embolic events, and a 6.4% clinically driven target lesion revascularization rate at 6 months. The 40-lesion chronic total occlusion (CTO) subset (mean lesion length 82±38 mm) achieved a similar significant reduction in stenosis to 35.5%±13.6% after Pantheris alone (p<0.001). Histological analysis of atherectomy specimens confirmed <1% adventitia in 82.1% of the samples, highlighting the precision of OCT guidance. Characterization of the OCT-guided lesions revealed evidence of an underestimation of disease burden when using fluoroscopy.

CONCLUSION

OCT-guided atherectomy for femoropopliteal disease is safe and effective. Additionally, the precision afforded by OCT guidance leads to greater removal of plaque during atherectomy while sparing the adventitia.

Clot Extraction With the FlowTriever Device in Acute Massive Pulmonary Embolism

Clinical guidelines support the use of systemic thrombolytic therapy for acute massive pulmonary embolism (PE). When anticoagulation and thrombolysis fail or are contraindicated, options become limited. We report an acute PE case in which treatment options were limited, and a novel device, the FlowTriever (Inari Medical, Irvine, California), was successfully used. This is the first case report of the use of this device that we are aware of.

Diagnostic imaging capabilities of the Ocelot -Optical Coherence Tomography System, ex-vivo evaluation and clinical relevance

BACKGROUND

Optical coherence tomography (OCT) is a high-resolution sub-surface imaging modality using near-infrared light to provide accurate and high contrast intra-vascular images. This enables accurate assessment of diseased arteries before and after intravascular intervention. This study was designed to corroborate diagnostic imaging equivalence between the Ocelot and the Dragonfly OCT systems with regards to the intravascular features that are most important in clinical management of patients with atherosclerotic vascular disease. These intravascular features were then corroborated in vivo during treatment of peripheral arterial disease (PAD) pathology using the Ocelot catheter.

METHODS

In order to compare the diagnostic information obtained by Ocelot (Avinger Inc., Redwood City, CA) and Dragonfly (St. Jude Medical, Minneapolis, MN) OCT systems, we utilized ex-vivo preparations of arterial segments. Ocelot and Dragonfly catheters were inserted into identical cadaveric femoral peripheral arteries for image acquisition and interpretation. Three independent physician interpreters assessed the images to establish accuracy and sensitivity of the diagnostic information. Histologic evaluation of the corresponding arterial segments provided the gold standard for image interpretation. In vivo clinical images were obtained during therapeutic interventions that included crossing of peripheral chronic total occlusions (CTOs) using the Ocelot catheter.

RESULTS

Strong concordance was demonstrated when matching image characteristics between both OCT systems and histology. The Dragonfly and Ocelot system's vessel features were interpreted with high sensitivity (91.1-100%) and specificity (86.7-100%). Inter-observer concordance was documented with excellent correlation across all vessel features. The clinical benefit that the Ocelot OCT system provided was demonstrated by comparable procedural images acquired at the point of therapy.

CONCLUSIONS

The study demonstrates equivalence of image acquisition and consistent physician interpretation of images acquired by the Ocelot and the Dragonfly OCT systems in-spite of distinct image processing algorithms and catheter configurations. This represents a dramatic shift away from both fluoroscopic imaging and diagnostic-only OCT imaging during peripheral arterial intervention towards therapeutic devices that incorporate real time diagnostic OCT imaging. In the clinical practice, these diagnostic capabilities have translated to best-in-class safety and efficacy for CTO crossing using the Ocelot catheter.

Complete percutaneous approach for arterial access in transfemoral transcatheter aortic valve replacement: a comparison with surgical cut-down and closure

OBJECTIVES

This study sought to investigate the immediate safety and feasibility of complete percutaneous access/closure of arteriotomy for device deployment compared to the surgical approach for transfemoral transcatheter aortic valve replacement (TAVR).

BACKGROUND

The percutaneous approach for arterial access for device deployment in transfemoral TAVR is a potential alternative to the surgical approach.

METHODS

In 274 patients who underwent transfemoral TAVR using Edward Sapien heart valve, 140 had a complete percutaneous approach using a "pre-closure" technique whereas 134 had surgical cut-down/repair for arterial access/closure of device deployment. Immediate vascular access/closure success, associated complications and clinical outcomes were compared.

RESULTS

While overall acute success of access/closure and in-hospital access-related events were similar, significant isolated stenosis/dissection at the access site developed more frequently in the percutaneous group (7.1% vs. 0.7%, P = 0.007). Contrary, wound infections requiring prolonged antibiotics use or surgical debridement occurred more frequently in the surgical group (0.7% vs. 6.7%, P = 0.007). Although the rate of major vascular complications was not different, the surgical group developed more frequent minor bleeding (27.1% vs. 38.8%, P = 0.04) and underwent transfusion of packed red blood cells of ≤3 units (25.7% vs. 43.3%, P = 0.002). Median hospital stay was shorter in the percutaneous group (3 days vs. 4 days, P = 0.002).

CONCLUSIONS

The percutaneous approach is a feasible access/closure method with a potential of lowering access site infection and bleeding, and shortening hospital stay, while maintaining similar rates of major vascular complications compared to the surgical approach.

A randomized, controlled pilot study of autologous CD34+ cell therapy for critical limb ischemia

BACKGROUND

Critical limb ischemia portends a risk of major amputation of 25% to 35% within 1 year of diagnosis. Preclinical studies provide evidence that intramuscular injection of autologous CD34+ cells improves limb perfusion and reduces amputation risk. In this randomized, double-blind, placebo-controlled pilot study, we evaluated the safety and efficacy of intramuscular injections of autologous CD34+ cells in subjects with moderate or high-risk critical limb ischemia, who were poor or noncandidates for surgical or percutaneous revascularization (ACT34-CLI).

METHODS AND RESULTS

Twenty-eight critical limb ischemia subjects were randomized and treated: 7 to 1 × 10(5) (low-dose) and 9 to 1 × 10(6) (high-dose) autologous CD34+ cells/kg; and 12 to placebo (control). Intramuscular injections were distributed into 8 sites within the ischemic lower extremity. At 6 months postinjection, 67% of control subjects experienced a major or minor amputation versus 43% of low-dose and 22% of high-dose cell-treated subjects (P=0.137). This trend continued at 12 months, with 75% of control subjects experiencing any amputation versus 43% of low-dose and 22% of high-dose cell-treated subjects (P=0.058). Amputation incidence was lower in the combined cell-treated groups compared with control group (6 months: P=0.125; 12 months: P=0.054), with the low-dose and high-dose groups individually showing trends toward improved amputation-free survival at 6 months and 12 months. No adverse safety signal was associated with cell administration.

CONCLUSIONS

This study provides evidence that intramuscular administration of autologous CD34+ cells was safe in this patient population. Favorable trends toward reduced amputation rates in cell-treated versus control subjects were observed. These findings warrant further exploration in later-phase clinical trials.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00616980.

Comparison between transradial and transfemoral percutaneous coronary intervention in acute ST-elevation myocardial infarction

Transradial (TR) access is increasingly being used in percutaneous coronary intervention (PCI). However, its role in PCI for ST-segment elevation myocardial infarction remains controversial because of concerns of procedural complexity adversely affecting the promptness of reperfusion. In this study, 150 consecutive patients who underwent PCI for acute ST-segment elevation myocardial infarction over a period of 24 months were prospectively evaluated; 46 had TR access (31%) and 104 (69%) had transfemoral (TF) access. All patients received thienopyridines, aspirin, and heparin per routine management. There were no significant differences between the TR access and TF access groups with respect to age (62.2 ± 11.6 vs 64.7 ± 14.1, p = 0.28), gender (76.1% vs 72.1% men, p = 0.69), or incidence of diabetes (23.9% vs 26.9%, p = 0.84). The TR and TF access groups were comparable with respect to door-to-balloon time (79.2 ± 32.3 vs 86.8 ± 51.8 minutes, p = 0.67) and amount of contrast used (190.5 ± 101.5 vs 172.2 ± 81.7 ml, p = 0.24). Total fluoroscopy time was longer in the TR access group compared to the TF access group (21.7 ± 12.7 vs 14.4 ± 10.4 minutes, p <0.0001). Postprocedural Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow was comparable for the 2 groups (87% for the TF group and 96% for the TR group, p = 0.15). There were no vascular complications in the TR access group compared to the TF access group (0% vs 5.8%, p = 0.18). In conclusion, this single-center observational study shows that TR access for PCI in STEMI is feasible and that it has fewer vascular complications and shorter length of hospital stay than the TF approach.

Giant saphenous vein graft aneurysm causing left atrial compression and cardiogenic shock

Saphenous vein graft aneurysm is a rare complication of coronary artery bypass graft (CABG) surgery that is challenging to manage and is associated with catastrophic consequences. We present the case of a 72-year-old woman with prior CABG surgery who presented with chest pain and was found to have a giant saphenous vein graft pseudoaneurysm. Further evaluation revealed that a vein graft pseudoaneurysm was causing significant compression of the left atrium. The pseudoaneurysm was successfully excluded from the blood flow with a covered stent; however, despite intra-aortic balloon pump and supportive therapy, the patient succumbed to cardiogenic shock and sepsis.

Impact of nitroglycerin and verapamil on coronary arterial distensibility as assessed by intravascular ultrasound

OBJECTIVES

To examine the effects of coronary artery vasodilators on coronary arterial distensibility using intravascular coronary ultrasound (IVUS).

BACKGROUND

There is limited information on the effect of coronary artery vasodilators on coronary arterial distensibility.

METHODS

We studied 20 patients using IVUS. Patients received 100 microg of nitroglycerin (10 patients) or 1 mg of verapamil (10 patients) intravenously. We measured coronary arterial elasticity, the distensibility index, compliance and stiffness index. There were no differences in patient characteristics, lesion characteristics or baseline coronary arterial distensibility between the two groups.

RESULTS

Systolic and diastolic blood pressure decreased in both groups (p < 0.05). Maximal coronary arterial cross-sectional luminal area (LA) during the cardiac cycle showed similar dilation in both groups. Nitroglycerin increased maximal LA by 5%, and verapamil increased it by 4% (p < 0.05; p < 0.0001, respectively). However, the degree of dilation of the minimal LA during the cardiac cycle showed a different pattern. Nitroglycerin dilated the minimal LA by 8%, while verapamil dilated the minimal LA by 2% (p < 0.001, p < 0.05, respectively). Consequently, the degree of expansion of LA during each cardiac cycle increased in the verapamil group and decreased in the nitroglycerin group. Thus, nitroglycerin decreased elasticity by 31% (p < 0.001), with no change in compliance, stiffness index or distensibility index. While, verapamil increased elasticity by 37%, the distensibility index by 48% and compliance by 53%, and decreased the stiffness index by 27% (all, p < 0.0001).

CONCLUSIONS

While both drugs acutely dilate the coronary arteries, nitroglycerin reduced local coronary arterial distensibility; however, verapamil increased local coronary arterial distensibility.

Comparison of drug-eluting stents with bare metal stents in unselected patients with acute myocardial infarction

OBJECTIVES

The aim of this study was to compare the procedural characteristics and outcomes of patients with acute myocardial infarction treated with drug-eluting stents (DES) vs. bare metal stents (BMS).

BACKGROUND

DES have been shown to reduce the incidence of restenosis and target vessel revascularization (TVR) in clinical randomized studies when compared with BMS in patients undergoing elective percutaneous intervention. Limited data are available with the use of DES in patients with acute ST-segment elevation myocardial infarction.

METHODS

Two hundred and sixty-one consecutive patients who presented with myocardial infarction between 7/2001 and 8/2005 were studied. The procedural characteristics, 30-day and 12-month outcomes of 131 patients treated with DES were compared with 130 patients treated with BMS.

RESULTS

At 12-months follow-up DES therapy was associated with a substantial decrease in major adverse cardiovascular events (MACE) (HR 0.33; P =0.002), TVR (HR 0.19; P =0.002), and recurrent myocardial infarction (HR 0.23; P =0.051) vs. BMS therapy. Coronary interventions utilizing DES were characterized by a marked increase in the number of stent per target vessel (DES: 1.9 +/- 0.9 vs. BMS: 1.38 +/- 0.6, P < 0.0001), treatment of bifurcation (DES: 21% vs. BMS: 5%, P =0.0004), and multivessel intervention (DES: 22% vs. BMS: 8%, P =0.003).

CONCLUSION

The routine use of DES in acute myocardial infarction is associated with reduced rates of MACE at 12 months vs BMS, despite a higher rate of complex procedures in the DES treated patients. In addition to its anti-restenosis effect, the improved outcome of patients treated with DES may be linked to a more complete revascularization in association with prolonged clopidogrel therapy.

Comparison of Coronary Artery Bypass Surgery With Percutaneous Coronary Intervention With Drug-Eluting Stents for Unprotected Left Main Coronary Artery Disease

OBJECTIVES

This study evaluated the clinical outcomes of consecutive, selected patients treated with coronary artery bypass graft (CABG) surgery or percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for unprotected left main coronary artery (ULMCA) disease.

BACKGROUND

Although recent data suggest that PCI with DES provides better clinical outcomes compared to bare-metal stenting for ULMCA disease, there is a paucity of data comparing PCI with DES to CABG.

METHODS

Since April 2003, when DES first became available at our institution, 123 patients underwent CABG, and 50 patients underwent PCI with DES for ULMCA disease.

RESULTS

High-risk patients (Parsonnet score >15) comprised 46% of the CABG group and 64% of the PCI group (p = 0.04). The 30-day major adverse cardiac and cerebrovascular event (MACCE) rate for CABG and PCI was 17% and 2% (p < 0.01), respectively. The mean follow-up was 6.7 +/- 6.2 months in the CABG group and 5.6 +/- 3.9 months in the PCI group (p = 0.26). The estimated MACCE-free survival at six months and one year was 83% and 75% in the CABG group versus 89% and 83% in the PCI group (p = 0.20). By multivariable Cox regression, Parsonnet score, diabetes, and CABG were independent predictors of MACCE.

CONCLUSIONS

Despite a higher percentage of high-risk patients, PCI with DES for ULMCA disease was not associated with an increase in immediate or medium-term complications compared with CABG. Our data suggest that a randomized comparison between the two revascularization strategies for ULMCA may be warranted.

Drug-eluting stenting is superior to bare metal stenting in saphenous vein grafts

This study compared the outcomes of percutaneous coronary intervention (PCI) of saphenous vein grafts (SVGs) with drug-eluting stents (DES) with bare metal stents (BMS). PCI of degenerated SVG is associated with worse outcomes and high incidence of in-stent restenosis compared with PCI of native coronary arteries. There is a paucity of data on the outcomes of PCI of SVG with DES. Data from 223 consecutive patients who underwent PCI of SVG were imputed into a dedicated clinical database. We assessed the clinical outcomes at a mean follow-up of 9.1+/-2.1 months. A total of 139 patients underwent PCI of SVG with DES and 84 patients with BMS. The mean age of the SVG was 7.6+/-3.8 years in the DES group and 7.7+/-2.8 years in the BMS group (P=0.38). Procedural success was achieved in all patients except for one patient in the BMS group who underwent emergent coronary artery bypass graft surgery for SVG dissection. There were no other in-hospital cardiac events in both groups. There was one cardiac death in the DES group and three deaths in the BMS group (P=0.03). When compared to the BMS, PCI of SVG with DES was associated with a lower incidence of myocardial infarction (4.3% vs. 20.2%; P=0.04) and target vessel revascularization (10.1% vs. 36.9%; P=0.035). When compared with BMS, PCI of SVG with DES was associated with a lower incidence of death, myocardial infarction, and target vessel revascularization.

Pilot prospective evaluation of counterpulsation with different intra-aortic balloon volumes on cardiac performance in humans

Smaller intra-aortic balloons (IAB) may minimize peripheral vascular complications. To determine the influence of different IAB volumes on cardiac performance, we studied 20 hemodynamically stable patients on IAB counterpulsation. Variables were measured with either a 40cc or 32cc IAB displacement, at an assist ratio of 1:1 or 1:8: Heart rate, Ao and PA pressures, and Fick cardiac output. By echo-Doppler, the velocity time integral (VTI) across the LV outflow tract, a measure of stroke volume was also calculated. The mean age was 60 yr (range 18-77), height 5'6" (5'2"-5'11"), and body surface area 1.9M2 (1.5-2.3). Results presented as mean values were: [table: see text] *P < 0.005 1:1 vs 1:8 for both 40 and 32cc IAB.

CONCLUSION

IAB pumping at 1:1 with either 40 cc or 32 cc volume displacement yields similar degrees of improvement in cardiac performance. A larger cohort is required to determine if smaller balloons may decrease complications without compromising efficacy.