Transcatheter Implantation of an Aortic Valve Prosthesis in a Female Patient With Severe Bicuspid Aortic Stenosis

PMID: 21900294

Vascular Access in Transcatheter Aortic Valve Implantation

The positive early experiences with TAVI however, revealed that vascular access remains a hindrance to broader application and success of the procedure.

This article will review the most common vascular routes used to deliver transcatheter aortic valves, and describe a new technique via the right axillary/subclavian artery approach.

PMID: 21879288

Intra-Aortic Balloon Counterpulsation and Infarct Size in Patients With Acute Anterior Myocardial Infarction Without Shock: The CRISP AMI Randomized Trial

OBJECTIVES: Intra-aortic balloon counterpulsation (IABC) is an adjunct to revascularization in patients with cardiogenic shock and reduces infarct size when placed prior to reperfusion in animal models.To determine if routine IABC placement prior to reperfusion in patients with anterior ST-segment elevation myocardial infarction (STEMI) without shock reduces myocardial infarct size.

METHODS: An open, multicenter, randomized controlled trial, the Counterpulsation to Reduce Infarct Size Pre-PCI Acute Myocardial Infarction (CRISP AMI) included 337 patients with acute anterior STEMI but without cardiogenic shock at 30 sites in 9 countries from June 2009 through February 2011.Intervention Initiation of IABC before primary percutaneous coronary intervention (PCI) and continuation for at least 12 hours (IABC plus PCI) vs primary PCI alone.Main Outcome Measures Infarct size expressed as a percentage of left ventricular (LV) mass and measured by cardiac magnetic resonance imaging performed 3 to 5 days after PCI. Secondary end points included all-cause death at 6 months and vascular complications and major bleeding at 30 days. Multiple imputations were performed for missing infarct size data.

RESULTS: The median time from first contact to first coronary device was 77 minutes (interquartile range, 53 to 114 minutes) for the IABC plus PCI group vs 68 minutes (interquartile range, 40 to 100 minutes) for the PCI alone group (P = .04). The mean infarct size was not significantly different between the patients in the IABC plus PCI group and in the PCI alone group (42.1% [95% CI, 38.7% to 45.6%] vs 37.5% [95% CI, 34.3% to 40.8%], respectively; difference of 4.6% [95% CI, -0.2% to 9.4%], P = .06; imputed difference of 4.5% [95% CI, -0.3% to 9.3%], P = .07) and in patients with proximal left anterior descending Thrombolysis in Myocardial Infarction flow scores of 0 or 1 (46.7% [95% CI, 42.8% to 50.6%] vs 42.3% [95% CI, 38.6% to 45.9%], respectively; difference of 4.4% [95% CI, -1.0% to 9.7%], P = .11; imputed difference of 4.8% [95% CI, -0.6% to 10.1%], P = .08). At 30 days, there were no significant differences between the IABC plus PCI group and the PCI alone group for major vascular complications (n = 7 [4.3%; 95% CI, 1.8% to 8.8%] vs n = 2 [1.1%; 95% CI, 0.1% to 4.0%], respectively; P = .09) and major bleeding or transfusions (n = 5 [3.1%; 95% CI, 1.0% to 7.1%] vs n = 3 [1.7%; 95% CI, 0.4% to 4.9%]; P = .49). By 6 months, 3 patients (1.9%; 95% CI, 0.6% to 5.7%) in the IABC plus PCI group and 9 patients (5.2%; 95% CI, 2.7% to 9.7%) in the PCI alone group had died (P = .12).

CONCLUSIONS: Among patients with acute anterior STEMI without shock, IABC plus primary PCI compared with PCI alone did not result in reduced infarct size.

PMID: 21878431

Optical Coherence Tomographic Comparison of Neointimal Coverage Between Sirolimus-and Resolute Zotarolimus-Eluting Stents at 9 Months After Stent Implantation

OBJECTIVES: The Resolute zotarolimus-eluting stent (ZES-R) has a thinner stent strut with biocompatible polymer than first generation drug-eluting stents. However, minimal optical coherencetomography (OCT) data exists about vascular responses after ZES-R implantation.

METHODS: This study investigated OCT findings in ZES-R implantation and compared them to those in sirolimus-eluting stent (SES) implantation. A total of 123 lesions (43 ZES-R and 80 SES) in 111 patients were evaluated with OCT at 9 months after stent implantation. Strut apposition, neointimalhyperplasia (NIH) thickness, and stent coverage on each stent strut were evaluated.

RESULTS: Mean NIH thickness was significantly greater in ZES-R-treated lesions than in SES-treated lesions (166 ± 73 μm vs. 96 ± 63 μm, respectively, P < 0.001). The percentage of uncovered strut was significantly lower in ZES-R-treated lesions than in SES-treated lesions (4.4 ± 4.8% vs. 10.3 ± 13.2%, respectively, P = 0.05). The percentage of malapposed struts was also significantly lower in ZES-R-treated than in SES-treated lesions (0.1 ± 0.4% vs. 1.5 ± 4.2%, respectively, P = 0.002). Intracoronary thrombus was less frequently detected in ZES-R-treated lesions (4.7% vs. 30.0%, respectively, P = 0.001).

CONCLUSIONS: ZES-R showed a lower incidence of uncovered or malapposed stent struts and intracoronary thrombus than SES at 9-month follow-up OCT examination. Compared with SES, ZES-R may elicit more favorable vascular responses at the expense of an increased neointimal proliferation.

PMID: 2185865

Optical Coherence Tomography: Has Its Time Come?

Cardiologists using intravascular ultrasound (IVUS) towards the end of the past millennium can recall the time when enthusiasm for a method that was initially seen purely as a powerful research tool began to be substituted by the awareness that intravascular imaging had the potential to revolutionise our understanding of the mechanisms of coronary interventions. Such a revolution occurred in Milan when Antonio Colombo and his group applied ultrasound to elucidate the mechanism of stent thrombosis, at that time common despite high levels of anticoagulation.

PMID: 21730261

Prognostic Implications of Nonobstructive Coronary Plaques in Patients With Non-ST-Segment Elevation Myocardial Infarction: A Multidetector Computed Tomography Study

OBJECTIVES: We sought to determine whether the amount of noncalcified plaque (NCP) in nonobstructive coronary lesions as detected by multidetector computed tomography (MDCT) was a predictor of future coronary events. Patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) frequently have multiple coronary plaques, which may be detected with MDCT.

METHODS: We included 312 consecutive patients presenting with NSTEMI, who underwent 64-slice MDCT coronary angiography and coronary artery calcium scoring before invasive coronary angiography. All patients were treated according to current guidelines based on an invasive treatment approach. Quantitative measurements of plaque composition and volume were performed by MDCT in all nonobstructive coronary lesions. The endpoint was cardiac death, acute coronary syndrome, or symptom-driven revascularization.

RESULTS: After a median follow-up of 16 months, 23 patients had suffered a cardiac event. Age, male sex, and diabetes mellitus were all associated with an increasing amount of NCP. In a multivariate regression analysis for events, the total amount of NCP in nonobstructive lesions was independently associated with an increased hazard ratio (1.18/100-mm(3) plaque volume increase, p = 0.01). Contrary to this, neither Agatston score nor the amount of calcium in nonobstructive lesions was associated with an increased risk.

CONCLUSIONS: Multidetector computed tomography plaque imaging identified patients at increased risk of recurrent coronary events after NSTEMI by measuring the total amount of NCP in nonobstructive lesions. The amount of calcified plaque was not associated with an increased risk.

PMID: 21777748

Low-Gradient Aortic Valve Stenosis – Myocardial Fibrosis and its Influence on Function and Outcome

OBJECTIVES: This prospective cohort study in patients with aortic stenosis (AS) aimed to identify surrogates of myocardial fibrosis that are easy to derive in clinical practice, allow the differentiation of low-gradient severe AS from moderate AS, and have an impact on clinical outcome. In patients with symptomatic aortic AS, a characteristic subgroup (i.e., up to one-third) exhibits severe AS with a concomitant low mean valve gradient either with preserved or reduced ejection fraction (EF). It is hypothesized that these patients tend to have an advanced stage of myocardial fibrosis and poor clinical outcome.

METHODS: Eighty-six patients with moderate or severe AS were examined by echocardiography including conventional aortic valve assessment, mitral ring displacement, and strain-rate imaging. Replacement fibrosis was quantified by late-enhancement magnetic resonance imaging. Biopsy samples were taken from patients with severe AS (n = 69) at aortic valve replacement. All patients were followed for 9 months.

RESULTS: Patients were divided into 4 groups according to aortic valve area (<1.0 cm(2)), mean valve gradient ≥40 mm Hg, and EF (<50%): group 1, moderate AS (n = 17); group 2, severe AS/high gradient (n = 49); group 3, severe AS/low gradient/preserved EF (n = 11); and group 4, severe AS/low gradient/decreased EF (n = 9). At baseline, a significant decrease in mitral ring displacement and systolic strain rate was detected in patients with low-gradient AS. In low-gradient groups, a higher degree of interstitial fibrosis in biopsy samples and more late-enhancement magnetic resonance imaging segments were observed. A close inverse correlation was found between interstitial fibrosis and mitral ring displacement (r = -0.79, p < 0.0001). Clinical outcome was best for patients in group 1, whereas mortality risk increased substantially in groups 2 through 4.

CONCLUSIONS: In severe AS, a low gradient is associated with a higher degree of fibrosis, decreased longitudinal function, and poorer clinical outcome despite preserved EF. Mitral ring displacement differentiates between moderate AS and low-gradient/severe AS with preserved EF.

PMID: 21757118

Coronary CT Angiographic Characteristics of Culprit Lesions in Acute Coronary Syndromes Not Related to Plaque Rupture as Defined by Optical Coherence Tomography and Angioscopy

OBJECTIVES: Pathological and clinical optical coherence tomography (OCT) studies have indicated that acute coronary syndrome (ACS) lesions have either ruptured fibrous caps (RFC-ACS) or intact fibrous caps (IFC-ACS). Although computed tomographic (CT) angiographic characteristics of RFC-ACS include low-attenuation plaques and positive plaque remodelling, features associated with IFC-ACS have not been previously described. The aim of this study was to assess the CT characteristics of IFC-ACS lesions.

METHODS: Seventy-four patients with ACS/stable angina consented to multimodality imaging, of which 66 underwent CTangiography. Of these, 57 culprit lesions in 57 patients were evaluated with sufficient image quality from all four of OCT, angioscopy, intravascular ultrasound, and CT angiography. Intraluminal thrombus was assessed by OCT/angioscopy, and culprit lesions further classified by OCT-based demonstration of fibrous cap integrity.

RESULTS: Of 35 culprit lesions with ACS, OCT revealed IFC with thrombus in 10 (29%) and
RFC in the remaining 25 (71%); all 22 lesions with stable angina had intact fibrous caps. Fibrous caps were significantly thinner in RFC-ACS than IFC-ACS and stable angina (45 ± 12, 131 ± 57, and 321 ± 146 μm, respectively; P = 0.001). CT angiography revealed that low-attenuation plaques were more frequently observed in RFC-ACS than IFC-ACS and stable angina (88, 40, and 18%; P = 0.001) lesions. Similarly, positive remodelling was more predominantly seen in RFC-ACS than IFC-ACS and stable angina (96, 20, and 14%; P = 0.001). However, none of the specific CT angiography features clearly distinguished IFC-ACS from stable lesions.

CONCLUSIONS: In contrast to the situation with RFC-ACS, distinct culprit lesion characteristics associated with non-rupture-related mechanisms are not identified by CT angiography. It will therefore not be possible to differentiate plaques likely to develop IFC-ACS from stable plaques.

PMID: 21719455

Appropriateness of Percutaneous Coronary Intervention

OBJECTIVES: Despite the widespread use of percutaneous coronary intervention (PCI), the appropriateness of these procedures in contemporary practice is unknown. The objective is to assess the appropriateness of PCI in the United States.

METHODS: Design, Setting, and Patients Multicenter, prospective study of patients within the National Cardiovascular Data Registry undergoing PCI between July 1, 2009, and September 30, 2010, at 1091 US hospitals. The appropriateness of PCI was adjudicated using the appropriate use criteria for coronary revascularization. Results were stratified by whether the procedure was performed for an acute (ST-segment elevation myocardial infarction, non–ST-segment elevation myocardial infarction, or unstable angina with high-risk features) or nonacute indication.

RESULTS: Of 500, 154 PCIs, 355 417 (71.1%) were for acute indications (ST-segment elevation myocardial infarction, 103, 245 [20.6%]; non–ST-segment elevation myocardial infarction, 105, 708 [21.1%]; high-risk unstable angina, 146, 464 [29.3%]), and 144 737 (28.9%) for nonacute indications. For acute indications, 350, 469 PCIs (98.6%) were classified as appropriate, 1,055 (0.3%) as uncertain, and 3,893 (1.1%) as inappropriate. For nonacute indications, 72, 911 PCIs (50.4%) were classified as appropriate, 54, 988 (38.0%) as uncertain, and 16, 838 (11.6%) as inappropriate. The majority of inappropriate PCIs for nonacute indications were performed in patients with no angina (53.8%), low-risk ischemia on noninvasive stress testing (71.6%), or suboptimal (≤1 medication) antianginal therapy (95.8%). Furthermore, although variation in the proportion of inappropriate PCI across hospitals was minimal for acute procedures, there was substantial hospital variation for nonacute procedures (median hospital rate for inappropriate PCI, 10.8%; interquartile range, 6.0%-16.7%).

CONCLUSIONS: In this large contemporary US cohort, nearly all acute PCIs were classified as appropriate. For nonacute indications, however, 12% were classified as inappropriate, with substantial variation across hospitals

PMID:

Environmental Impact of Cardiac Imaging Tests For the Diagnosis of Coronary Artery Disease

OBJECTIVES: The use of cardiovascular imaging is growing inexorably and concerns have been expressed about its cost and radiation safety.

METHODS: In this study, the relative environmental impact of MRI, single photon emission tomography and cardiac ultrasound (echo) for the diagnosis of coronary artery disease were examined.

RESULTS: The results emphasise that echo causes the least environmental impact at each stage of its life cycle. The effect of one echo on human health, ecosystem effects and resource use was of the order of 1-20% of those of the alternative methods.

CONCLUSIONS: Although there are circumstances in which one imaging modality is preferred on clinical grounds, when everything else is equal, these results support the selection of echocardiography as the preferred test on environmental grounds.

PMID: 21685481

Predictors of Abdominal Aortic Aneurysm Sac Enlargement After Endovascular Repair

OBJECTIVES: The majority of infrarenal abdominal aortic aneurysm (AAA) repairs in the United States are performed with endovascular methods. Baseline aortoiliac arterial anatomic characteristics are fundamental criteria for appropriate patient selection for endovascular aortic repair (EVAR) and key determinants of long-term success. We evaluated compliance with anatomic guidelines for EVAR and the relationship between baseline aortoiliac arterial anatomy and post-EVAR AAA sac enlargement.

METHODS: Patients with pre-EVAR and at least 1 post-EVAR computed tomography scan were identified from the M2S, Inc. imaging database (1999 to 2008). Preoperative baseline aortoiliac anatomic characteristics were reviewed for each patient. Data relating to the specific AAA endovascular device implanted were not available. Therefore, morphological measurements were compared with the most liberal and the most conservative published anatomic guidelines as stated in each manufacturer’s instructions for use.

RESULTS: The primary study outcome was post-EVAR AAA sac enlargement (>5-mm diameter increase). In 10 228 patients undergoing EVAR, 59% had a maximum AAA diameter below the 55-mm threshold at which intervention is recommended over surveillance. Only 42% of patients had anatomy that met the most conservative definition of device instructions for use; 69% met the most liberal definition of device instructions for use. The 5-year post-EVAR rate of AAA sac enlargement was 41%. Independent predictors of AAA sac enlargement included endoleak, age ≥80 years, aortic neck diameter ≥28 mm, aortic neck angle >60°, and common iliac artery diameter >20 mm.

CONCLUSIONS: In this multicenter observational study, compliance with EVAR device guidelines was low and post-EVAR aneurysm sac enlargement was high, raising concern for long-term risk of aneurysm rupture.

PMID: 21478500

Assessment of Echo-Attenuated Plaque by Optical Coherence Tomography and its Impact on Post-Procedural Creatine Kinase-Myocardial Band Elevation in Elective Stent Implantation

OBJECTIVES: Recent intravascular ultrasound studies have described atherosclerotic plaques with echo attenuation (EA) without associated bright echoes that are correlated with no-reflow phenomenon after PCI. This study examined morphological characteristics of echo-attenuated plaques by optical coherence tomography (OCT) and evaluated their influence on creatine kinase-myocardial band (CK-MB) elevation after percutaneous coronary intervention (PCI) in patients with elective stent implantation.

METHODS: We studied 135 native de novo culprit coronary lesions in 135 patients with normal pre-PCI CK-MB levels (28 with unstable angina; 107 with stable angina) who underwent intravascular ultrasound and OCT examinations before elective stent implantation. The lesions were divided into 2 groups based on the presence or absence of EA, and OCT findings were compared. We then determined predictors of post-PCI CK-MB elevation.

RESULTS: EA was found in 47 (34.8%) lesions and was associated with the presence of OCT-derived thin-capped fibroatheroma, ruptured plaques, greater lipid content, intravascular ultrasound-derived large reference and plaque area, lesion eccentricity, and microcalcification. Elevated CK-MB levels were observed in 36 (26.7%) lesions, and significantly more frequently in lesions with EA than without. In multivariable analysis, EA (odds ratio [OR]: 3.49; 95% confidence interval [CI]: 1.53 to 7.93; p = 0.003) and OCT-derived ruptured plaque (OR: 2.92; 95% CI: 1.21 to 7.06; p = 0.017) were independent predictors of post-PCI CK-MB elevation.

CONCLUSIONS: Atherosclerotic plaques with EA were associated with characteristics considered to be high risk or unstable. OCT examination showed an additive predictive value to the presence of EA for post-PCI CK-MB elevation.

PMID: 21596319

Detection of Disrupted Plaques by Coronary CT: Comparison With Angioscopy

OBJECTIVES: Disrupted plaques are the major cause of acute coronary syndrome (ACS). Although the detection of vulnerable plaques by coronary CT (CCT) has been examined and reported, there has been no report on the detection of disrupted plaques by CCT. The objective was to test the ability of CCT to detect disrupted coronary plaques.

METHODS: 32 consecutive patients with suspected ischaemic heart disease who underwent successful coronary angioscopic examination and CCT were analysed. Yellow plaques of colour grade 1␣3 and disrupted yellow plaques were examined by angioscopy. CCT findings (low attenuation, positive remodelling and ring-like enhancement) were examined for each site of yellow plaques.

RESULTS: In the 32 patients, 65 yellow plaques were detected. Higher-colour-grade yellow plaques and disrupted yellow plaques had a significantly higher incidence of CCT findings: low attenuation (grade 1 vs grade 2 vs grade 3, 18% vs 59% vs 69%; non-disrupted vs disrupted, 36% vs 66%), positive remodelling (24% vs 59% vs 75%; 33% vs 75%), and ring-like enhancement (0% vs 19% vs 25%; 6% vs 44%). Positive and negative predictive values for ring-like enhancement to detect disrupted plaque were 88% and 63%, respectively; those for the combined CCT findings (low attenuation, positive remodelling and ring-like enhancement) to detect disrupted plaque were 90% and 58%, respectively.

CONCLUSIONS: CCT findings were associated with disrupted plaques confirmed by angioscopy. Ring-like enhancement had a high positive predictive value for detecting disrupted plaque.

PMID:

In Vivo Assessment of Optimal Viewing Angles From X-Ray Coronary Angiography

OBJECTIVES: To propose and validate a novel approach to determine the optimal angiographic viewing angles for a selected coronary (target) segment from X-ray coronary angiography, without the need to reconstruct the entire coronary tree in three-dimensions (3D), such that subsequent interventions are carried out from the best view.

METHODS: The approach starts with standard quantitative coronary angiography (QCA) of the target vessel in two angiographic views. Next, the target vessel is reconstructed in 3D, and in a very simple and intuitive manner, the possible overlap of the target vessel and other vessel segments can be assessed, resulting in the best view with minimum foreshortening and overlap. A retrospective study including 67 patients was set up for the validation. The overlap prediction result was compared with the true overlap on the available angiographic views (TEST views). The foreshortening for the views proposed by the new approach software viewing angle (SVA) and the views used during the stent deployment software viewing angle (EVA) were compared. Two experienced interventional cardiologists visually evaluated the success of SVA with respect to EVA. The evaluation results were graded into five values ranging from -2 to 2.

RESULTS: The overlap prediction algorithm successfully predicted the overlap condition for all 235 TEST views. EVA was associated with more foreshortening than SVA (8.9%±8.2% vs. 1.6%±1.5%, p<0.001). The average evaluated point for the success of SVA was 0.94±0.80 (p <0.001), indicating that the evaluators were in favor of the optimal views determined by the proposed approach versus the views used during the actual intervention.

CONCLUSIONS: The proposed approach is able to accurately and quickly determine the optimal viewing angles for the online support of coronary interventions.

PMID: 21550911

Prediction of the Annuloplasty Ring Size in Patients Undergoing Mitral Valve Repair Using Real-Time Three-Dimensional Transoesophageal Echocardiography

OBJECTIVES: We sought to investigate the additional value of real-time three-dimensional transoesophageal echocardiography (RT 3D TOE)-guided sizing for predicting annuloplasty ring size during mitral valve repair.

METHODS: In 53 patients undergoing elective mitral valve repair, an RT 3D TOE was performed
pre- and post-operatively. The digitally stored loops were imported into a software for mitral valve assessment. The annuloplasty ring size was predicted by superimposing computer-aided design (CAD) models of annuloplasty rings onto Live 3D zoom loops, measurement of the intercommissural distance, or the height of the anterior mitral leaflet. The surgeon implanted the annuloplasty ring according to the usual surgical technique and was blinded to the echocardiographic measurement results.

RESULTS: Pre-operative correlation between the selected ring size with mitral valve assessment and the actual implanted annuloplasty ring size was 0.91. The correlation for measurement of the intercommissural distance was 0.55 and for measurement of the height of the anterior mitral leaflet 0.75. The post-operative correlation with the actual implanted ring size was 0.96 for mitral valve assessment, 0.92 for intercommissural distance, and 0.79 for the anterior mitral leaflet height.

CONCLUSIONS: Superimposition of annuloplasty ring CAD models on the Live 3D zoom loops of the mitral valve using mitral valve assessment is superior to two-dimensional measurements of the intercommissural distance or the height of the anterior mitral leaflet in predicting correct annuloplasty ring size.

PMID: 21546375