Ostial right coronary artery lesion morphology and outcomes after treatment with drug-eluting stents.

BACKGROUND: Outcomes after percutaneous coronary intervention (PCI) for de novo ostial right coronary artery (RCA) lesions are poor. AIMS: We used intravascular ultrasound (IVUS) to clarify the morphological patterns of de novo ostial RCA lesions and their associated clinical outcome. METHODS: Among 5,102 RCA IVUS studies, 170 de novo ostial RCA stenoses (within 3 mm from the aorto-ostium) were identified. These were classified as 1) isolated ostial lesions (no disease extending beyond 10 mm from the ostium and without a calcified nodule [CN]); 2) ostial CN, typically with diffuse disease (disease extending beyond 10 mm); and 3) ostial lesions with diffuse disease but without a CN. The primary outcome was target lesion failure (TLF: cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischaemia-driven target lesion revascularisation). RESULTS: The prevalence of an isolated ostial lesion was 11.8% (n=20), 47.6% (n=81) were ostial CN, and 40.6% (n=69) were ostial lesions with diffuse disease. Compared to ostial lesions with diffuse disease, isolated lesions were more common in women (75.0% vs 42.0%; p=0.01), and CN were associated with older age (median [first, third quartile] 76 [70, 83] vs 69 [63, 81] years old; p=0.002). The Kaplan-Meier rate of TLF at 2 years was significantly higher in patients with CN (21.6%) compared to diffuse lesions (8.2%) (p=0.04), and patients with isolated lesions had no events. A multivariable Cox proportional hazard model revealed that CN were significantly associated with TLF (hazard ratio 6.63, 95% confidence interval: 1.28-34.3; p=0.02). CONCLUSIONS: Ostial RCA lesions have specific morphologies - detectable by IVUS - that may be associated with long-term clinical outcomes.

Comprehensive Management of ANOCA, Part 1-Definition, Patient Population, and Diagnosis: JACC State-of-the-Art Review.

Angina with nonobstructive coronary arteries (ANOCA) is increasingly recognized and may affect nearly one-half of patients undergoing invasive coronary angiography for suspected ischemic heart disease. This working diagnosis encompasses coronary microvascular dysfunction, microvascular and epicardial spasm, myocardial bridging, and other occult coronary abnormalities. Patients with ANOCA often face a high burden of symptoms and may experience repeated presentations to multiple medical providers before receiving a diagnosis. Given the challenges of establishing a diagnosis, patients with ANOCA frequently experience invalidation and recidivism, possibly leading to anxiety and depression. Advances in scientific knowledge and diagnostic testing now allow for routine evaluation of ANOCA noninvasively and in the cardiac catheterization laboratory with coronary function testing (CFT). CFT includes diagnostic coronary angiography, assessment of coronary flow reserve and microcirculatory resistance, provocative testing for endothelial dysfunction and coronary vasospasm, and intravascular imaging for identification of myocardial bridging, with hemodynamic assessment as needed.

Comprehensive Management of ANOCA, Part 2-Program Development, Treatment, and Research Initiatives: JACC State-of-the-Art Review.

Centers specializing in coronary function testing are critical to ensure a systematic approach to the diagnosis and treatment of angina with nonobstructive coronary arteries (ANOCA). Management leveraging lifestyle, pharmacology, and device-based therapeutic options for ANOCA can improve angina burden and quality of life in affected patients. Multidisciplinary care teams that can tailor and titrate therapies based on individual patient needs are critical to the success of comprehensive programs. As coronary function testing for ANOCA is more widely adopted, collaborative research initiatives will be fundamental to improve ANOCA care. These efforts will require standardized symptom assessments and data collection, which will propel future large-scale clinical trials.

Mechanisms and treatment outcomes of ostial right coronary artery in-stent restenosis.

BACKGROUND: Despite a high rate of in-stent restenosis (ISR) after stenting the right coronary artery (RCA) ostium, the mechanism of ostial RCA ISR is not well understood. AIMS: We aimed to clarify the cause of ostial RCA ISR using intravascular ultrasound (IVUS). METHODS: Overall, 139 ostial RCA ISR lesions were identified with IVUS, pre-revascularisation. Primary ISR mechanisms were classified as follows: 1) neointimal hyperplasia (NIH); 2) neoatherosclerosis; 3) ostium not covered by the stent; 4) stent fracture or deformation; 5) stent underexpansion (old minimum stent area <4.0 mm2 or stent expansion <50%); or 6) a protruding calcified nodule. RESULTS: The median duration from prior stenting was 1.2 (first quartile 0.6, third quartile 3.1) years. The primary mechanisms of ISR were NIH in 25% (n=35) of lesions, neoatherosclerosis in 22% (n=30), uncovered ostium in 6% (n=9) (biological cause 53%, n=74), stent fracture or deformation in 25% (n=35), underexpansion in 11% (n=15), and protruding calcified nodules in 11% (n=15) (mechanical cause 47%, n=65). Including secondary mechanisms, 51% (n=71) of ostial RCA ISRs had stent fractures that were associated with greater hinge motion of the ostial-aorta angle during the cardiac cycle. The Kaplan-Meier rate of target lesion failure at 1 year was 11.5%. When the mechanically caused ISRs were treated without new stents, they suffered a higher subsequent event rate (41.4%) compared with non-mechanical causes or mechanical causes treated without restenting (7.8%, unadjusted hazard ratio 6.44, 95% confidence interval: 2.33-17.78; p<0.0001). CONCLUSIONS: Half of the ostial RCA ISRs were due to mechanical causes. Subsequent event rates were high, especially in mechanically caused ISRs treated without the implantation of a new stent.

Impact of Nonobstructive Left Main Coronary Artery Atherosclerosis on Long-Term Mortality.

BACKGROUND: Although the presence of severe stenosis in the left main coronary artery (LMCA) is a well-established predictor of mortality, whether this extends to nonobstructive atherosclerosis in the LMCA is unknown. OBJECTIVES: The aim of this study was to evaluate the association between LMCA disease by intravascular ultrasound (IVUS) and long-term mortality. METHODS: Between 2005 and 2013, 3,239 patients with LMCA IVUS imaging without LMCA revascularization (either before angiography or scheduled based on index angiography or IVUS) were included. The primary and secondary endpoints were all-cause and cardiac mortality at a minimum of 5 years obtained from the National Death Index. RESULTS: The IVUS-measured LMCA minimum lumen area (MLA) and plaque burden were 13.1 ± 5.0 mm2 and 41.7% ± 15.6%, respectively. The median follow-up was 8.2 years. The Kaplan-Meier estimated 12-year all-cause and cardiac death rates were 37.5% and 17.0%, respectively. Greater plaque burden (unadjusted HR per 10%: 1.17; 95% CI: 1.12-1.22; P < 0.0001) and smaller IVUS MLA (unadjusted HR per 1 mm2: 0.98; 95% CI: 0.96-0.99; P = 0.0008) were associated with all-cause death. After adjusting for clinical, angiographic, and IVUS factors, plaque burden (adjusted HR per 10%: 1.12; 95% CI: 1.04-1.21; P = 0.003) but not MLA (adjusted HR per 1 mm2: 1.02; 95% CI: 0.99-1.04; P = 0.18) was associated with long-term all-cause death. These findings were also consistent for long-term cardiac mortality. CONCLUSIONS: In the present large-scale study with a 12-year follow-up, increasing LMCA plaque burden was associated with long-term all-cause and cardiac mortality in patients not undergoing LMCA revascularization, even when the lumen area was preserved.

Safety of Provocative Testing With Intracoronary Acetylcholine and Implications for Standard Protocols.

BACKGROUND: Heterogeneity in diagnostic criteria and provocation protocols has posed challenges in understanding the safety of coronary provocation testing with intracoronary acetylcholine (ACh) for the contemporary diagnosis of epicardial and microvascular spasm. OBJECTIVES: We examined the safety of testing and subgroup differences in procedural risks based on ethnicity, diagnostic criteria, and provocation protocols. METHODS: PubMed and Embase were searched in November 2021 to identify original articles reporting procedural complications associated with intracoronary ACh administration. The primary outcome was the pooled estimate of the incidence of major complications including death, myocardial infarction, ventricular tachycardia/fibrillation, and shock. RESULTS: A total of 16 studies with 12,585 patients were included in the meta-analysis. The overall pooled estimate of the incidence of major complications was 0.5% (95% CI: 0.0%-1.3%) without any reports of death. Exploratory subgroup analyses revealed that the pooled incidence of major complications was significantly higher in the studies that followed the contemporary diagnosis criteria for epicardial spasm defined as ≥90% diameter reduction (1.0%; 95% CI: 0.3%-2.0%) but significantly lower in Western populations (0.0%; 95% CI: 0.0%-0.45%). The rate of positive epicardial spasm and the incidence of major complications were similar between provocation protocols using the maximum ACh doses of 100 µg and 200 µg. CONCLUSIONS: Intracoronary ACh administration for the contemporary diagnosis of epicardial and microvascular spasm is a safe procedure. Moreover, excellent safety records are observed in Western populations primarily presenting with myocardial ischemia and/or infarction with nonobstructive coronary arteries. This study will help standardize ACh testing to improve clinical diagnosis and ensure procedural safety.

Percutaneous Axillary Access for Placement of Microaxial Ventricular Support Devices: The Axillary Access Registry to Monitor Safety (ARMS).

BACKGROUND: There has been increasing utilization of short-term mechanical circulatory support devices for a variety of clinical indications. Many patients have suboptimal iliofemoral access options or reasons why early mobilization is desirable. Axillary artery access is an option for these patients, but little is known about the utility of this approach to facilitate short-term use for circulatory support with microaxial pump devices. METHODS: The Axillary Access Registry to Monitor Safety (ARMS) was a prospective, observational multicenter registry to study the feasibility and acute safety of mechanical circulatory support via percutaneous upper-extremity access. RESULTS: One hundred and two patients were collected from 10 participating centers. Successful device implantation was 98% (100 of 102). Devices were implanted for a median of 2 days (interquartile range, 0-5 days; range, 0-35 days). Procedural complications included 10 bleeding events and 1 stroke. There were 3 patients with brachial plexus-related symptoms all consisting of C8 tingling and all arising after multiple days of support. Postprocedural access site hematoma or bleeding was noted in 9 patients. Device explantation utilized closure devices alone in 61%, stent grafts in 17%, balloon tamponade facilitated closure in 15%, and planned surgical explant in 5%. Duration of support appeared to be independently associated with a 1.1% increased odds of vascular complication per day ([95% CI, 0.0%-2.3%] P=0.05). CONCLUSIONS: Percutaneous axillary access for use with microaxial support pumps appears feasible with acceptable rates of bleeding despite early experience. Larger studies are necessary to confirm the pilot data presented here.

The effectiveness of excimer laser angioplasty to treat coronary in-stent restenosis with peri-stent calcium as assessed by optical coherence tomography.

AIMS: We aimed to evaluate the effectiveness of excimer laser coronary angioplasty (ELCA) to treat in-stent restenosis (ISR) due to peri-stent calcium-related stent underexpansion as assessed by optical coherence tomography (OCT). METHODS AND RESULTS: We studied 81 patients (81 lesions with ISR, stent underexpansion, and peri-stent calcium >90°) who underwent OCT imaging both pre and post percutaneous coronary intervention and compared lesions treated with ELCA (n=23) vs. without ELCA (n=58). ELCA use was associated with more calcium fracture (ELCA: 61%, non-ELCA: 12%, p<0.01), larger final minimum lumen area (ELCA: 4.76 mm2 [3.25, 5.57], non-ELCA: 3.46 mm2 [2.80, 4.13], p<0.01), and a larger previously implanted stent area (ELCA: 6.15 mm2 [4.83, 7.09], non-ELCA: 4.65 mm2 [3.84, 5.40], p<0.01). In the multivariable model, ELCA use was associated with peri-stent calcium fracture (odds ratio 46.5, 95% confidence interval: 6.8, 315.9, p<0.001) that, in turn, was associated with final larger lumen and stent dimensions. Finally, contrast injection during ELCA was associated with multiple calcium fractures and fractures even in thicker calcium. CONCLUSIONS: ELCA is effective for treating ISR with underexpansion by disrupting peri-stent calcium, facilitating better expansion of the previously implanted stent.

EC-VAD: Combined Use of Extracorporeal Membrane Oxygenation and Percutaneous Microaxial Pump Left Ventricular Assist Device.

Combination of venoarterial extracorporeal membrane oxygenation (VA-ECMO) and a percutaneous microaxial left ventricular assist device (pLVAD), or "EC-VAD," has been reported in cases of left ventricular decompression with mixed results. We conducted a retrospective review of patients who received EC-VAD (n = 29) or isolated VA-ECMO therapy (ECMO-only; n = 196) for refractory cardiogenic shock between February 2011 and October 2014. Fourteen patients received VA-ECMO and then Impella pLVAD (E→EC-VAD), and 15 received the Impella pump then VA-ECMO (I→EC-VAD). E→EC-VAD patients demonstrated decreased pulmonary artery systolic (36.00 ± 16.84 mm Hg versus 30.63 ± 12.13 mm Hg; p = 0.049) and diastolic (24.25 ± 13.45 mm Hg versus 17.25 ± 7.96 mm Hg, p = 0.049) pressures by 24 hours post-EC-VAD implant. In the same period, I→EC-VAD patients demonstrated improved SvO2 (43.14 ± 16.75% versus 75.18 ± 13.88%, p = 0.043) and PaO2/FiO2 ratio (148.55 ± 67.69 mm Hg versus 374.51 ± 170.97 mm Hg, p = 0.043). Thirty-day survival rates were 42.9% in E→EC-VAD, 46.7% in I→EC-VAD, and 49.0% in ECMO-only (p = 0.913). Hemolysis occurred more in EC-VAD patients (44.83% versus 17.35% in ECMO-only, p = 0.002); however, there was no increased frequency of other adverse events including bleeding and lower limb ischemia. Despite increased hemolysis, combined use of VA-ECMO and pLVAD may improve or circumvent left ventricular distension in refractory cardiogenic shock while promoting adequate blood flow.

Intravascular ultrasound analysis of intraplaque versus subintimal tracking in percutaneous intervention for coronary chronic total occlusions: One year outcomes.

OBJECTIVES: We sought to determine the 1-year outcomes of patients receiving successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) procedures comparing subintimal versus intraplaque wire tracking patterns. BACKGROUND: CTO PCI utilizes both intraluminal and subintimal wire tracking to achieve successful percutaneous revascularization. Intravascular ultrasound (IVUS) can be used to precisely determine the path of wire tracking. METHODS: From 2014 to 2016, data from patients undergoing CTO PCI were collected in a single-center database. The primary composite endpoint was target vessel failure (TVF) defined as cardiovascular death, target vessel myocardial infarction (MI), or target vessel revascularization (TVR). RESULTS: In total 157 patients with successful CTO PCI and concomitant IVUS imaging completed 1-year follow-up. Subintimal tracking was detected in 53.5% of cases and those patients had a higher incidence of prior PCI, prior coronary artery bypass grafting, and higher J-CTO score. At 1-year, the unadjusted rate of TVF in the subintimal tracking group was higher than the intraplaque group (17.9 vs. 6.9%, HR 2.74, 95% CI 1.00-7.54, P = 0.04), driven by numerically higher rates of TVR and peri-procedural MI. After multivariable adjustment, no significant differences in the rates of the TVF between subintimal vs. intraplaque groups were present at 1-year (TVF: HR 1.51, 95% CI 0.38-6.00, P = 0.55). Landmark analysis excluding in-hospital events showed no significant differences in TVF to 1-year. CONCLUSIONS: IVUS-detected subintimal tracking was observed in over half of successful CTO PCI cases and correlated with baseline and angiographic factors that contributed to the overall rate of TVF at 1-year.

Bifurcation and ostial optical coherence tomography mapping (BOOM) - Case description of a novel bifurcation stent technique.

Stent placement guided by angiography alone is often inexact, but of increased importance with bifurcation percutaneous coronary intervention (PCI). We describe a novel technique using optical coherence tomography (OCT)-guided angiographic co-registration termed "Bifurcation and Ostial OCT Mapping" (BOOM). The technique is based on the precise identification and mapping of the side-branch ostium using co-registration to minimize protrusion of stent struts into the main branch while ensuring full coverage of the ostium in the side-branch.

Association of Stress Test Risk Classification With Health Status After Chronic Total Occlusion Angioplasty (from the Outcomes, Patient Health Status and Efficiency in Chronic Total Occlusion Hybrid Procedures [OPEN-CTO] Study).

Stress testing is endorsed by the American College of Cardiology/American Heart Association Appropriate Use Criteria to identify appropriate candidates for Chronic Total Occlusion (CTO) Percutaneous Coronary Intervention (PCI). However, the relation between stress test risk classification and health status after CTO PCI is not known. We studied 449 patients in the 12-center OPEN CTO registry who underwent stress testing before successful CTO PCI, comparing outcomes of patients with low-risk (LR) versus intermediate to high-risk (IHR) findings. Health status was assessed using the Seattle Angina Questionnaire Angina Frequency (SAQ AF), Quality of Life (SAQ QoL), and Summary Scores (SAQ SS). Stress tests were LR in 40 (8.9%) and IHR in 409 (91.1%) patients. There were greater improvements on the SAQ AF (LR vs IHR 14.2 ± 2.7 vs 23.3 ± 1.3 points, p <0.001) and SAQ SS (LR vs IHR 20.8 ± 2.3 vs 25.4 ± 1.1 points, p = 0.03) in patients with IHR findings, but there was no difference between groups on the SAQ QoL domain (LR vs IHR 24.8 ± 3.4 vs 27.3 ± 1.6 points, p = 0.42). We observed large health status improvements after CTO PCI in both the LR and IHR groups, with the greatest reduction in angina among those with IHR stress tests. Although patients with higher risk studies may experience greater reduction in angina symptoms, on average, patients with LR stress tests also experienced large improvements in symptoms after CTO PCI, suggesting patients with refractory symptoms should be considered appropriate candidates for CTO PCI regardless of stress test findings.

Intravascular ultrasound comparison of left main coronary artery disease between white and Asian patients.

We assessed the ethnic differences in coronary atherosclerosis lesion morphology between white and Asian patients. Our hypothesis was that left main coronary artery (LMCA) disease was more focal and less complex in Asian than in Western white patients. We studied 99 Asian patients (Japan and South Korea) and 99 matched control United States white patients with a stable clinical presentation and >30% LMCA angiographic diameter stenosis by visual estimation. The matching parameters included age, gender, and diabetes mellitus. The vessel and lumen areas and calcium arc were analyzed every 0.5 mm and normalized for analysis length. Overall, 75.1% of the patients were men and 34.1% had diabetes. The patient age was 68.0 ± 10 years, with no differences between the Asian and white patients. The Asian patients had a lower prevalence of hyperlipidemia than the white patients (41.4% vs 81.8%; p <0.0001) and were smaller in size, and the white patients were more obese (body mass index 23.7 ± 2.6 vs 27.6 ± 4.1 kg/m(2), p <0.0001). The Asian patients had a smaller lumen area (5.2 ± 1.8 vs 6.2 ± 14 mm(2); p <0.0001), larger vessel area (20.0 ± 4.9 vs 18.4 ± 4.4 mm(2); p <0.0001), and larger plaque burden (72 ± 10 vs 64 ± 12%: p <0.0001) at the minimum lumen site and over the entire LMCA length. The white patients had more calcification, whether assessed by the maximum arc (82° ± 74° vs 49° ± 45°; p <0.0001) or total length (3.6 ± 3.2 vs 2.1 ± 2.1 mm; p <0.0001). In conclusion, after matching well-known risk factors, there appeared to be ethnic differences in coronary atherosclerosis morphology between Asian and white patients, at least as it affected LMCA morphology.

Serial gray scale intravascular ultrasound findings in late drug-eluting stent restenosis.

The primary aim of the present study was to assess the gray scale intravascular ultrasound (IVUS) findings that might be associated with late drug-eluting stent restenosis. The study included 47 patients (54 lesions) who had undergone either baseline IVUS-guided stent implantation or IVUS-guided repeat stenting to treat in-stent restenosis and then had IVUS follow-up data for ≥1.5 years afterward without any intervening procedures. The left anterior descending artery was the culprit in 59% of cases, and 50% of the lesions were at bifurcation sites. Quantitative and qualitative IVUS analyses showed a decreased minimum lumen area at follow-up from 6.0 ± 1.8 to 3.8 ± 1.4 mm(2) (p <0.0001) that was mainly due to neointimal hyperplasia with chronic stent recoil (defined as a >15% decrease in minimum stent area) in only 2 lesions and stent fracture in only 5 lesions. Calcified neointima appeared in 12 lesions, mostly in the form of macrocalcification, and was associated with increased calcium both behind the stent and in the reference segment. In conclusion, late drug-eluting stent restenosis showed neointimal calcification in 20% of cases, and chronic stent recoil was rare.

Updating the chest pain algorithm: incorporating new evidence on emerging antiplatelet agents.

In 2008, we published our chest pain protocol for the management of acute coronary syndromes (ACS) and acute myocardial infarction. Our algorithm was specifically designed for our institution, which includes primary percutaneous intervention (PCI) for all ST-elevation myocardial infarctions (STEMIs) and a preferred invasive approach for non-STEMIs. Since 2008, there have been changes in the adjunctive pharmacotherapeutic armamentarium for PCI in both the STEMI and non-STEMI ACS context. In particular, recent data on the novel antiplatelet agent prasugrel, dosing of clopidogrel after PCI, and interactions with clopidogrel and other medicines and substrates, which can lead to decreased platelet response to clopidogrel, have led us to update our ACS clinical pathway. We present our updated chest pain algorithm with a brief review of the rapidly evolving changes in adjunctive pharmacotherapy for PCI, and provide rationale for the changes that we have made to our institutional protocol. Clinical pathways need to be regularly updated and revised by incorporating new evidence from clinical trials to ensure optimal clinical care.

Prevalence and prediction of previously unrecognized peripheral arterial disease in patients with coronary artery disease: the Peripheral Arterial Disease in Interventional Patients Study.

BACKGROUND: Peripheral arterial disease (PAD) is under diagnosed in primary care practices, yet the extent of unrecognized PAD in patients with coronary artery disease (CAD) is unknown. OBJECTIVE: To assess the prevalence of previously unrecognized PAD in patients undergoing coronary angiography and/or intervention and to determine the relationship between presence of PAD and severity of CAD. METHODS: The Peripheral Arterial Disease in Interventional Patients Study (PIPS) is a prospective cohort study conducted at an inpatient service of a tertiary referral center. A total of 800 patients referred for coronary angiography without prior diagnosis of PAD aged 70 years or older or aged 50-69 years with a history of tobacco use and/or diabetes mellitus were included. Evaluation involved a medical history, a questionnaire to assess symptoms and functional status, and measurement of the ankle-brachial index (ABI). PAD was considered present if the ABI was 0.90 or less. RESULTS: The prevalence of previously unrecognized PAD was 15%, 95% CI (12.6-17.7) and was highest among patients over 70 years of age (25.2%) and in women (23.3%). Among patients with CAD, those with PAD had higher prevalence of left main and multivessel coronary artery disease (87.2% vs. 75.5%, P = 0.006). Alternatively, patients with multivessel CAD had a twofold higher risk of being diagnosed with previously unrecognized PAD compared with those with single vessel CAD [adjusted OR = 2.02, (95% CI 1.03-3.98)]. CONCLUSIONS: PAD is often overlooked even in patients with known ischemic heart disease under specialist cardiovascular care. Overlooked PAD in this population increases in frequency with advanced age, in women, and in the presence of other traditional cardiovascular risk factors. Furthermore, the presence of PAD in this population identifies a subgroup with more severe form of CAD.

Updating the chest pain algorithm: incorporating new evidence.

In 2003, we published our chest pain protocol for the management of acute coronary syndromes (ACSs) and acute myocardial infarction. Our algorithm was specifically designed for our institution, which was primary percutaneous coronary intervention (PCI) for all ST-elevation myocardial infarctions (STEMIs) and a preferred invasive approach for non-STEMIs. Since 2003, there have been numerous changes in the adjunctive pharmacotherapeutic armamentarium for PCI in both the STEMI and non-STEMI ACS context. We present our updated chest pain algorithm with a brief review of the rapidly evolving changes in adjunctive pharmacotherapy for PCI and provide a rationale for the changes that we have made to our institutional protocol. Clinical pathways need to be consistently updated and revises by incorporating new evidence from clinical trials in order to maintain clinical relevance.

Relation between the degree of procedural anticoagulation and complications after coronary stent implantation.

The impact of the degree of anticoagulation in patients who underwent stent implantation without glycoprotein IIb/IIIa inhibitors was examined in 1,020 patients. High levels of procedural anticoagulation with heparin were found to increase hemorrhagic complications without improving clinical or angiographic outcomes.