Physiological and angiographic outcomes of PCI in calcified lesions after rotational atherectomy or intravascular lithotripsy.

BACKGROUND: Percutaneous coronary interventions (PCI) in calcified coronary artery lesions are associated with impaired stent expansion, higher rate of periprocedural complications and cardiac mortality. Lesion preparation using calcium modifying techniques such as Rotational Atherectomy (RA) or Intravascular Lithotripsy (IVL) has been advocated. Studies comparing these technologies are lacking. We aimed to compare in-stent pressure gradients, evaluated by vessel fractional flow reserve (vFFR), in calcific lesions treated using either RA or IVL. METHODS: Patients undergoing either RA- or IVL-assisted PCI from two European centers were included. Propensity score matching (1:2) was performed to control for potential bias. Primary outcome was post-PCI in-stent pressure gradients calculated by vFFR (vFFRgrad). Secondary outcomes included the proportion of patients with complete functional revascularization defined as distal vFFR post-PCI (vFFRpost) ≥ 0.90. RESULTS: From a cohort of 210 patients, 105 matched patients (70 RA and 35 IVL) were included. Pre-PCI vFFR did not differ between groups (0.65 ± 0.13 RA and 0.67 ± 0.11 IVL). After PCI, in-stent pressure gradients were significantly lower in the IVL group (0.032 ± 0.026 vs 0.043 ± 0.026 in the RA group, p = 0.024). The proportions of vessels with functional complete revascularization was similar between the two groups (32.9% vs. 37.1% in the RA and IVL group, respectively; p = 0.669). CONCLUSIONS: Calcific lesions preparation with IVL is effective and resulted in lower in-stent pressure gradients compared to RA. Approximately one third of the patients undergoing PCI for a severely calcified lesion achieved functional revascularization with no difference between rotational RA and IVL.

Quantification of calcium burden by coronary CT angiography compared to optical coherence tomography.

Coronary artery calcifications (CAC) are frequently observed in patients referred for coronary CT angiography (CTA). Calcification volume (in mm3) can accurately be assessed during catheterization by optical coherence tomography (OCT). The aim of the present study was to investigate the accuracy of CTA-derived assessment of calcification volume as compared with OCT. 66 calcified plaques (32 vessels) from 31 patients undergoing OCT-guided PCI with coronary CT acquired as a standard of care were included. Coronary CT and OCT images were matched using fiduciary points. Calcified plaques were reconstructed in three dimensions to calculate calcium volume. A Passing-Bablok regression analysis and the Bland-Altman method were used to assess the agreement between imaging modalities. Twenty-seven left anterior descending arteries and 5 right coronary arteries were analyzed. Median calcium volume by CTA and OCT were 18.23 mm3 [IQR 8.09, 36.48] and 10.03 mm3 [IQR 3.6, 22.88] respectively; the Passing-Bablok analysis showed a proportional without a systematic difference (Coefficient A 0.08, 95% CI - 1.37 to 1.21, Coefficient B 1.61, 95% CI 1.45 to 1.84) and the mean difference was 9.69 mm3 (LOA - 10.2 to 29.6 mm3). No differences were observed for minimal lumen area (Coefficient A 0.07, 95% CI - 0.46 to 0.15, Coefficient B 0.85, 95% CI 0.64 to 1.2). CTA volumetric calcium evaluation overestimates calcium volume by 60% compared to OCT. This may allow for an appropriate interpretation of calcific burden in the non-invasive setting. Even in presence of calcific plaques, a good agreement in the MLA assessment was found. Coronary CT may emerge as a tool to quantify calcium burden for invasive procedural planning.

Ultra-low-dose CT for left atrium and pulmonary veins imaging using new model-based iterative reconstruction algorithm.

AIMS: To evaluate the feasibility of ultra-low-dose CT for left atrium and pulmonary veins using new model-based iterative reconstruction (MBIR) algorithm. METHODS AND RESULTS: Two hundred patients scheduled for catheter ablation were randomized into two groups: Group 1 (100 patients, Multidetector row CT (MDCT) with MBIR, no ECG triggering, tube voltage and tube current of 100 kV and 60 mA, respectively) and Group 2 [100 patients, MDCT with adaptive statistical iterative reconstruction algorithm (ASIR), no ECG triggering, and kV and mA tailored on patient BMI]. Image quality, CT attenuation, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) of left atrium (LA) and pulmonary veins, and effective dose (ED) were evaluated for each exam and compared between two groups.No significant differences between groups in terms of population characteristics, cardiovascular risk factors, anatomical features, prevalence of persistent atrial fibrillation and image quality score. Statistically significant differences were found between Group 1 and Group 2 in mean attenuation, SNR, and CNR of LA. Significantly, lower values of noise were found in Group 1 versus Group 2. Group 1 showed a significantly lower mean ED in comparison with Group 2 (0.41 ± 0.04 versus 4.17 ± 2.7 mSv). CONCLUSION: The CT for LA and pulmonary veins imaging using MBIR is feasible and allows examinations with very low-radiation exposure without loss of image quality.

Feasibility and diagnostic accuracy of a low radiation exposure protocol for prospective ECG-triggering coronary MDCT angiography.

AIM: To compare the feasibility, accuracy, and effective radiation dose (ED) of multidetector computed tomography (MDCT) in the detection of coronary artery disease using a combined ED-saving strategy including prospective electrocardiogram (ECG) triggering with a short x-ray window and a body mass index (BMI)-adapted imaging protocol using adaptive statistical iterative reconstruction (ASIR; group 1), in comparison with a prospective ECG triggering strategy alone (group 2). MATERIALS AND METHODS: One hundred and seventy patients scheduled for invasive coronary angiography (ICA) were evaluated. Fourteen patients were not eligible for MDCT. The remaining 156 patients were randomized to group 1 (78 patients) and group 2 (78 patients). Eight and 11 patients in groups 1 and 2, respectively, were excluded after randomization because the patients' heart rates were >65 beats/min. MDCT images were assessed for feasibility, signal-to-noise ration (SNR), and contrast-to-noise ratio (CNR), accuracy in detection of coronary stenoses >50% versus ICA and for ED. RESULTS: The feasibility, SNR, CNR, accuracy in a segment-based and patient-based model were similar in both groups (97 versus 95%, 14.5 ± 3.9 versus 14.2 ± 4.1, 16 ± 4.6 versus 16.5 ± 4.4, 95 versus 94% and 97 versus 99%, respectively). The ED in group 1 was 72% lower than in group 2 (2.1 ± 1.2 versus 7.5 ± 1.8 mSv, respectively; p<0.01). CONCLUSIONS: The use of a multi-parametric ED saving protocol results in a significant reduction in ED without a negative impact on accuracy.

Hemofiltration in the prevention of radiocontrast agent induced nephropathy.

AIM: The aim of the study was to investigate the role of hemofiltration in preventing contrast nephropathy in patients with renal failure. METHODS: We randomized 114 renal failure patients undergoing percutaneous coronary interventions (PCI) to either peri-procedural hemofiltration or saline hydration. RESULTS: Contrast nephropathy occurred in 5% of hemofiltration-treated patients and in 50% in controls (P<0.01). In-hospital event rate as well as in-hospital and 1-year mortality rates were lower in patients treated with hemofiltration. CONCLUSION: In patients with renal failure undergoing PCI, peri-procedural hemofiltration is effective for the prevention of contrast nephropathy, and is associated with improved in-hospital and long-term outcome.

Contemporary antithrombotic strategies in patients undergoing coronary stent implantation.

The number of annual stenting procedures has been increasing at a rapid pace since coronary stents were first used in clinical practice just over a decade ago. Subacute stent thrombosis, which usually has serious clinical consequences, plagued the stent early experience despite intense anticoagulation therapy. The reduction of stent thrombosis was among the factors that contributed to stent growth and widespread acceptance in recent years. This was the result of improved implantation techniques, advances in adjunctive pharmacotherapy and evolution in stent designs, delivery systems and non-thrombogenic coatings. However, novel designs and materials customized for particular lesion types and newer anti-restenotic treatments could influence stent thrombogenicity. Intravascular brachytherapy and drug-eluting stents have been shown to reduce the incidence of in-stent restenosis preventing cellular proliferation. However, by interfering with the re-endothelization process they may also increase the risk of stent thrombosis. To prevent a recrudescence of this feared complication, future research direction must focus on the hemocompatibility aspects of new technologies, along with further refinement of stent-deployment techniques and antithrombotic strategies.

Patent ductus arteriosus closure using the new Amplatzer Duct Occluder. Preliminary results and review of the literature.

BACKGROUND: Patent ductus arteriosus (PDA) is the second most common congenital heart disease. A large number of surgical and transcatheter techniques for the interruption or closure of PDA has been reported. The aim of this study was to assess the immediate and short-term results of transcatheter closure of PDA using the new, self-expandable, self-centering, and repositionable Amplatzer Duct Occluder device. METHODS: We attempted occlusion of PDA with the Amplatzer Duct Occluder in seven consecutive patients, one child and six adults, four females and three males, between September 1999 and January 30th 2000. All PDAs but one were approached from the femoral venous site; the Amplatzer Duct Occluder size was selected in order to be 2 mm larger than the duct's diameter at its narrowest site and the mean PDA diameter was 5.4+/-2.5 mm (range 3-9). All patients underwent physical examination, chest X-ray and echocardiography within 48 hours and on first and third month after PDA occlusion. RESULTS: Four patients had a megaphone type (type A), and three had an elongated, conical type (type E) PDA. Four patients had immediate, complete angiographic closure of the ductus 10 minutes after the procedure, one had a trace shunt and two had small shunts which all disappeared within 48 hours. The average fluoroscopy time and procedural time were 34.4+/-10.6 min (range 21-50) and 105+/-38.9 min (range 75-190) respectively. There were no complications at follow-up. CONCLUSIONS: Transcatheter closure of PDA using the new Amplatzer Duct Occluder is an easy and effective technique. Moreover it is safe even in the presence of wide PDAs.

Transcatheter treatment of coronary artery disease and atrial septal defect with sequential implantation of coronary stent and Amplatzer septal occluder: preliminary results.

Coronary stent implantation had been established as a highly effective revascularization technique in patients with occlusive coronary artery disease. Transcatheter closure of atrial septal defects is becoming a definite alternative to surgery in properly selected patients. During a 19-month period, 6 patients (50% women; mean age, 58 +/- 17 years; range, 32-73 years) of a consecutive series of 176 prospective multicenter registry patients undergoing transcatheter atrial septal defect closure were treated with sequential percutaneous coronary revascularization and Amplatzer septal occluder implantation. Indication for revascularization was stable angina in four patients and unstable angina in two. Indication for defect closure was significant left-to-right shunt with right ventricular enlargement. Defect diameter ranged from 13 to 20 mm by transesophageal echocardiography, and the stretched diameter measured 13 to 25 mm. Procedural success of both interventions was achieved in all cases without in-hospital complications. A total of seven stents were successfully implanted in five coronary vessels. No stent was used in one patient after successful PTCA. Immediate total closure of the defect was obtained in five patients. Trivial residual shunting, observed in one patient, disappeared at 24 hr. No adverse cardiac events, recurrence of anginal symptoms, or evidence of residual shunt were observed at clinical and echocardiographic follow-up, which ranged from 60 to 390 days (mean, 258 +/- 150 days). These results suggest that sequential transcatheter therapy of coronary artery disease and atrial septal defect is safe and efficacious in selected patients.

Endovascular repair of latrogenic subclavian artery perforations using the Hemobahn stent-graft.

PURPOSE: To report the use of a new self-expanding endograft for percutaneous treatment of iatrogenic subclavian artery perforations. CASE REPORTS: The subclavian artery of 2 patients was inadvertently cannulated during percutaneous attempts to implant a permanent pacemaker in one and catheterize the subclavian vein in the other. Because both patients had serious comorbidities, endovascular repair of the subclavian perforations was performed using the Hemobahn endograft, a nitinol stent covered internally with expanded polytetrafluoroethylene. The endoprostheses were successfully deployed via an ipsilateral brachial artery access. No signs of endograft occlusion, migration, deformation, or fracture have been observed during follow-up at 12 and 10 months, respectively, in these patients. CONCLUSIONS: The Hemobahn stent-graft appears well suited to repairing subclavian artery injuries. Longer follow-up will determine if the design of this endograft will resist compression in this vascular location.

Extent and distribution of in-stent intimal hyperplasia and edge effect in a non-radiation stent population.

Intimal hyperplasia within the body of the stent is the primary mechanism for in-stent restenosis; however, stent edge restenosis has been described after brachytherapy. Our current understanding about the magnitude of in vivo intimal hyperplasia and edge restenosis is limited to data obtained primarily from select, symptomatic patients requiring repeat angiography. The purpose of this study was to determine the extent and distribution of intimal hyperplasia both within the stent and along the stent edge in relatively nonselect, asymptomatic patients scheduled for 6-month intravascular ultrasound (IVUS) as part of a multicenter trial: Heparin Infusion Prior to Stenting. Planar IVUS measurements 1 mm apart were obtained throughout the stent and over a length of 10 mm proximal and distal to the stent at index and follow-up. Of the 179 patients enrolled, 140 returned for repeat angiography and IVUS at 6.4 +/- 1.9 months and had IVUS images adequate for analysis. Patients had 1.2 +/- 0.6 Palmaz-Schatz stents per vessel. There was a wide individual variation of intimal hyperplasia distribution within the stent and no mean predilection for any location. At 6 months, intimal hyperplasia occupied 29.3 +/- 16.2% of the stent volume on average. Lumen loss within 2 mm of the stent edge was due primarily to intimal proliferation. Beyond 2 mm, negative remodeling contributed more to lumen loss. Gender, age, vessel location, index plaque burden, hypercholesterolemia, diabetes, and tobacco did not predict luminal narrowing at the stent edges, but diabetes, unstable angina at presentation, and lesion length were predictive of in-stent intimal hyperplasia. In a non-radiation stent population, 29% of the stent volume is filled with intimal hyperplasia at 6 months. Lumen loss at the stent edge is due primarily to intimal proliferation.

Elective coronary stent implantation in cardiogenic shock complicating acute myocardial infarction: in-hospital and six-month clinical and angiographic results.

Effective treatment of patients with acute myocardial infarction and cardiogenic shock depends on restoring persistent patency of the infarct-related artery. Coronary stenting, reducing abrupt or delayed closure related to dissection and suboptimal result, may improve PTCA results in cardiogenic shock. Eighteen patients (14 males and 4 females, mean age 59 +/- 7 years), referred to catheterization laboratory for acute myocardial infarction and shock, had elective stent implantation during 14 primary and 4 rescue PTCA. Time delay between shock onset and PTCA was 4.1 +/- 3 hr (range, 30 min to 12 hr). The IRA was LAD in seven patients (38%), LCx in two (11%), and RCA in eight (45%). One patient (5.%) had distal LMCA occlusion. Stent deployment was successful in 100% of patients and resulted in TIMI 3 flow in 13 (72%) patients. In 13 (72%) cases, cardiogenic shock gradually resolved and the patients were discharged alive. Five patients (28%) died because of irreversible hemodynamic deterioration without evidence of reinfarction. At 6-month follow-up, all the discharged patients were alive and no patient had reinfarction or recurrent angina. Heart transplant was required in one patient 5 months after stenting because of refractory congestive heart failure. Angiography demonstrated patency of all the coronary arteries treated, with TIMI 3 flow in all patients. Stent restenosis rate was 30%, and target lesion revascularization with CABG or re-PTCA was not required in any case. LV function improved from 39% +/- 15% to 51% +/- 15% (P < 0.01). Elective coronary stenting is an effective treatment for acute myocardial infarction complicated by cardiogenic shock and may improve acute and long-term survival.

Use of a new diagnostic catheter for transradial internal mammary artery angiography early after minimally invasive coronary bypass.

We describe a new diagnostic catheter specifically designed for selective catheterization of the left internal mammary artery via the ipsilateral radial approach. We used this catheter to assess the patency of the distal mammary-left anterior descending coronary artery anastomosis in 30 consecutive patients early after minimally invasive direct coronary artery bypass grafting. The new catheter design allowed easy and fast engagement of the left internal mammary artery leading to optimal vessel opacification in all cases. Angiography revealed graft problems in seven (23.3%) patients, two of whom required anastomosis revision, surgical in one case and with PTCA in the other. No LIMA injury occurred as a result of selective catheterization. Patients with functionally normal anastomosis were discharged on the same day of the diagnostic procedure.

Heparin infusion prior to stenting (HIPS) trial: final results of a prospective, randomized, controlled trial evaluating the effects of local vascular delivery on intimal hyperplasia.

BACKGROUND: Local delivery of pharmacologic agents or genes at the site of angioplasty is a promising approach to reduce restenosis. However, there are unresolved questions concerning the safety and feasibility of local vascular delivery in clinical practice as well as the efficacy of delivered drug. To this end, the safety, feasibility, and efficacy of local delivery of heparin were evaluated in the Heparin Infusion Prior to Stenting (HIPS) trial. METHODS AND RESULTS: A total of 179 patients were enrolled in this multicenter, randomized, prospective, core laboratory-evaluated trial. Patients were randomly assigned to 5000 U heparin either administered to the coronary artery lumen or infused into the arterial wall immediately after angioplasty and before stent placement. End points included procedural events and clinical, angiographic, and intravascular ultrasound events at 6 months. Patient groups were evenly matched. There was no difference in the incidence of arterial injury, defined as an increase in arterial dissection, acute closure, or decrease in Thrombolysis In Myocardial Infarction grade blood flow in the group receiving local delivery. At follow-up there was no difference in the major adverse event rate between intraluminal (22.7%) and local groups (24.7%). There was no difference between intraluminal and local therapy in the angiographic in-stent restenosis rate (12.5%, 12.7%) or the in-stent volumetric analysis by intravascular ultrasound (IVUS) (37.19 +/- 20. 86 mm(3) vs 43.79 +/- 25.52 mm(3)). CONCLUSIONS: Local delivery of 5000 U heparin into the arterial wall before stent implantation is safe and feasible. There was not a favorable effect of locally delivered heparin on clinical, angiographic, or IVUS end points of restenosis. The use of IVUS to measure volume of intimal hyperplasia in a multicenter, core laboratory-controlled trial is feasible.

Successful stent delivery with deep seating of 6 French guiding catheters in difficult coronary anatomy.

Despite improvements in coronary stent design, delivery difficulties may still be encountered. Between April 1996 and September 1998, 945 patients underwent coronary stenting in our Institute. New 6 Fr Long Brite Tip (LBT) guiding catheters, allowing deep coronary artery intubation and increased backup support, were used in 25 (2.6%) of these patients presenting complex coronary anatomy and poor stent accessibility, electively in 3 (12%) and after stent delivery failure with multiple (2.1 +/- 1.2) standard guiding catheters in 22 (88%). Deep coronary artery intubation (>/= 20 mm) was successfully performed in 22 (88%) patients and was associated with adequate pressure recording and contrast opacification without blood flow compromise. Ten (22.7%) Palmaz-Schatz stents and 34 (77.3%) second-generation stents of various lengths were successfully delivered to different coronary vessels (RCA = 15, LAD = 9, LCx = 1) in all patients in whom deep coronary intubation was obtained. These data demonstrate that deep coronary artery cannulation with LBT catheters is feasible and safe and may markedly increase the rate of stent delivery success in very complex coronary anatomy and when standard guiding catheters have failed.

Successful dissolution of occlusive coronary thrombus with local administration of abciximab during PTCA.

Treatment of intracoronary thrombus poses difficult problems and may result in severe complications. We used a local delivery catheter (InfusaSleeve, LocalMed, Palo Alto, CA) to treat an occlusive coronary thrombus that was refractory to systemic thrombolysis and conventional angioplasty. After local administration of 10 mg of abciximab with this catheter there was successful resolution of coronary thrombus and vessel recanalization. Cathet. Cardiovasc. Intervent. 48:211-213, 1999.

Emergency stenting of totally occluded left main coronary artery in acute myocardial infarction.

We report a case of emergency stenting for acute occlusion of the left main coronary artery in the setting of acute myocardial infarction. Although stent implantation allowed prompt revascularization and successful immediate management of this life-threatening condition, subacute stent thrombosis occurred, requiring re-PTCA followed by surgical revascularization. This case suggests that stenting of an acutely occluded left main coronary artery may be a life-saving procedure but should only be used as a bridge to surgery rather than a definitive treatment modality.