Improvements in Left Ventricular Diastolic Mechanics After Parachute Device Implantation in Patients With Ischemia Heart Failure: A Cardiac Computerized Tomographic Study.

BACKGROUND: Percutaneous ventricular restoration therapy with the use of a left ventricle (LV)-partitioning Parachute device has emerged as a clinical treatment option for LV apical aneurysm after extensive anterior myocardial infarction (AMI). We assessed changes of diastolic mechanics and functional improvements following LV Parachute device implantation by means of cardiac computerized tomography (CCT). METHODS AND RESULTS: CCT data were obtained from 28 patients before and after LV Parachute device implantation. Diastolic functional indices were determined by means of quantitative CCT assessment: 1) transmitral velocities in early (E) and late (A) diastole and ratio (E/A); 2) early diastolic mitral septal tissue velocity (Ea) and E/Ea; and 3) vortex formation time (VFT). Functional improvements were assessed with the use of New York Heart Association (NYHA) functional classification. Among the study patients, there were no significant differences in all transmitral velocities and E/A, though there was significantly increased Ea, reduced E/Ea, and greater VFT 6 months after LV Parachute device implantation. Finally, the improvement of diastolic functional indices after Parachute treatment correlated with observed clinical functional alterations (Δ E/Ea and Δ NYHA functional class:, r = 0.563; P = .002; Δ VFT and Δ NYHA functional class: r = -0.507; P = .006). CONCLUSIONS: LV Parachute device implantation therapy in heart failure caused by AMI and LV apical aneurysm formation showed improvements in several diastolic functional mechanics according to CCT-based measures.

Impact of positive and negative lesion site remodeling on clinical outcomes: insights from PROSPECT.

OBJECTIVES: This study investigated coronary artery remodeling patterns associated with clinical outcomes. BACKGROUND: In the prospective, multicenter PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree: An Imaging Study in Patients With Unstable Atherosclerotic Lesions) study, reported predictors of nonculprit lesion (NCL) major adverse cardiac events (MACE) were an intravascular ultrasound (IVUS) minimal lumen area (MLA) ≤4 mm(2), a plaque burden ≥70%, and a IVUS-virtual histology (VH) thin-cap fibroatheroma (TCFA), but not lesion site remodeling. METHODS: Overall, 697 consecutive patients with an acute coronary syndrome were enrolled and underwent 3-vessel gray-scale and IVUS-VH; 3,223 NCLs were identified by IVUS. The remodeling index (RI) was calculated as the external elastic membrane area at the MLA site divided by the average of the proximal and distal reference external elastic membrane areas. First, one third of the patients were randomly selected to determine RI cutoffs related to NCL MACE (development cohort). Receiver-operating characteristic analysis showed that there were 2 separate cut points that predicted NCL MACE: RI = 0.8789 and RI = 1.0046 (area under the curve = 0.663). These cut points were used to define negative remodeling as an RI <0.88, intermediate remodeling as an RI of 0.88 to 1.00, and positive remodeling as an RI >1.00. Second, we used the remaining two-thirds of patients to validate these cut points with respect to lesion morphology and clinical outcomes (validation cohort). RESULTS: Kaplan-Meier curve analysis in the validation cohort showed that NCL MACE occurred more frequent (and equally) in negative and positive remodeling lesions compared with intermediate remodeling lesions. In this cohort, negative remodeling lesions had the smallest MLA, positive remodeling lesions had the largest plaque burden, and VH TCFA, especially VH TCFA with multiple necrotic cores, was most common in negatively remodeling lesions. CONCLUSIONS: The present study showed the novel concept that positive and negative lesion site remodeling was associated with unanticipated NCL MACE in the PROSPECT study. ( PROSPECT: An Imaging Study in Patients With Unstable Atherosclerotic Lesions [PROSPECT]; NCT00180466).

The PARACHUTE IV trial design and rationale: percutaneous ventricular restoration using the parachute device in patients with ischemic heart failure and dilated left ventricles.

BACKGROUND: Left ventricle (LV) remodeling after anterior wall myocardial infarction leads to increased LV volumes, myocardial stress, and, ultimately, heart failure (HF). Patients have high morbidity and mortality risk, and treatment remains limited. Percutaneous ventricular restoration (PVR) therapy using the Parachute device, a fluoropolymer membrane stretched over a nitinol conical frame, is a novel approach to partition off the damaged myocardium. In the European and United States PARACHUTE feasibility trials, the observed rates of death or rehospitalization for HF were <17% at 12 months. These data compare favorably with historical data and support the need of a randomized trial to determine the clinical efficacy of PVR on outcomes for patients with ischemic HF. OBJECTIVE: To determine the safety and efficacy of PVR utilizing a LV partitioning device, Parachute, in a randomized clinical trial compared with optimal medical therapy. METHODS: This US pivotal trial is approved by the Food and Drug Administration (ClinicalTrials.gov Identifier: NCT01286116) and will randomly assign (1:1) 478 patients with New York Heart Association class III-IV ischemic HF, akinetic or dyskinetic LV wall abnormality, and ejection fraction between 15% and 35% to optimal medical therapy (control) versus Parachute device implantation in approximately 65 hospitals. The primary endpoint is death or rehospitalization for worsening HF. Sample size calculation assumes constant hazards and follow-up ≥12 months using an event-driven trial design. CONCLUSIONS: We reported the rational and design of the first multicenter randomized trial to test the efficacy of PVR using the Parachute device to treat patients with ischemic HF and dilated LV.

Age- and gender-related changes in plaque composition in patients with acute coronary syndrome: the PROSPECT study.

AIMS: Atherosclerosis accelerates with increasing age; however, young women presenting with acute coronary syndromes (ACS) have adverse outcomes compared to men despite less obstructive coronary artery disease. We sought to evaluate the in vivo plaque characteristics and composition of untreated non-culprit lesions (NCL) at two ages (<65 years old and ≥65 years old) in patients with ACS and examine the effect of sex in both groups. METHODS AND RESULTS: Untreated NCLs from 697 patients with ACS were imaged with greyscale and radiofrequency intravascular ultrasound. NCL plaque morphology, burden, composition, and major adverse cardiac events (MACE) were analysed in both age groups, and a posterior sex-based sub-analysis was performed. Plaques from patients ≥65 (n=974) vs. <65 (n=2,275) years old were longer (median 12.62 mm vs. 10.75 mm, p=0.008) and had greater plaque burden (48.2% vs. 47.5%, p=0.001), necrotic core (12.5% vs. 11.0%, p=0.001) and dense calcium (5.7% vs. 4.0%, p<0.0001). Men <65 years old also had a greater number of fibroatheromas (3.0 vs. 2.0, p=0.007) and NCLs per patient (5.0 vs. 4.0, p=0.004) with larger plaque volumes (47.7% vs. 46.8%, p=0.04), and fewer fibrotic plaques (2.2% vs. 4.4%, p=0.03) than women in the same age group. These sex differences were not observed in patients ≥65 years old. The incidence of MACE during median 3.4 year follow-up did not significantly differ according to age in this study. CONCLUSIONS: The current study confirms in vivo that, with aging, plaque burden, necrotic core and calcium content increase significantly. Moreover, gender-specific differences in the extent and composition of coronary plaque are present in patients <65 years (but not ≥65 years) of age, which suggest differential sex-related effects on atherosclerosis development and progression.

Relation between angiographic lesion severity, vulnerable plaque morphology and future adverse cardiac events (from the Providing Regional Observations to Study Predictors of Events in the Coronary Tree study).

Previous angiographic studies have suggested that the future risk for major adverse cardiovascular events (MACEs) is related to coronary stenosis severity. The aim of this study was to use the grayscale and virtual histology (VH)-intravascular ultrasound (IVUS) data from the Providing Regional Observations to Study Predictors of Events in the Coronary Tree (PROSPECT) study to identify underlying lesion morphologic characteristics that might explain these findings. In PROSPECT, patients presenting with acute coronary syndromes in whom percutaneous coronary intervention was successful underwent 3-vessel grayscale and VH-IVUS and were followed for a median of 3.4 years for the incidence of MACEs. Overall, 3,115 nonculprit lesions detected by IVUS were divided into quartiles according to baseline angiographic diameter stenosis. From the first to fourth quartiles, there were increases in the prevalence of lesions with IVUS minimum luminal areas ≤ 4 mm(2), IVUS plaque burden ≥ 70%, and VH-IVUS thin-cap fibroatheroma (13.4%, 22.0%, 24.2%, and 30.3%, respectively, p <0.001), along with an increased frequency of plaque ruptures and greater necrotic core volumes. The incidence of lesions with plaque burden ≥ 70%, minimum luminal area ≤ 4 mm(2), and VH thin-cap fibroatheroma was highest in the fourth quartile (0%, 0.4%, 0.4%, and 2.8% in the first through fourth quartiles, respectively, p <0.001). Three-year MACE rates were also highest in the fourth quartile (0.3%, 0.7%, 1.3%, and 5.1%, respectively, p <0.001). In conclusion, increasing angiographic diameter stenosis was associated with an increased frequency of grayscale and VH-IVUS lesion morphologic features that have been associated with adverse events and that may, in part, explain why future MACEs were related to baseline lesion severity.

An intravascular ultrasound appraisal of atherosclerotic plaque distribution in diseased coronary arteries.

BACKGROUND: The assumption that atherosclerosis accumulates in the proximal coronary arteries and that distal segments are spared has yet to be systematically shown in vivo. METHODS: We used intravascular ultrasound to analyze complete proximal, mid, and distal segments from 75 diseased left anterior descending arteries (LADs) and 61 diseased right coronary arteries (RCAs) (including either the posterolateral [PLA; n = 38] or posterior descending artery [PDA; n = 23]) to document that distal coronary arteries are more often free of disease vs proximal vessels. External elastic membrane, lumen, and plaque and media areas were measured every 0.4 mm (median), and plaque burden (plaque and media/external elastic membrane) and percentage of normal (plaque and media thickness <0.3 mm) cross sections/segment were determined. RESULTS: Left anterior descending artery plaque was heaviest in proximal and mid segments, diminishing significantly in distal segments; plaque burden was 46% ± 9% in proximal, 39% ± 8% in mid, and 31% ± 9% in distal LAD (P < .0001), with 93% (median) of distal LAD cross sections being normal compared with 21% of mid and 0% of proximal cross sections (P < .0001). Right coronary artery plaque gradient was less pronounced vs the LAD; plaque burden was 37% ± 13% in proximal, 40% ± 10% in mid, and 36% ± 10% in distal RCA, followed by 31% ± 11% in PDA and 33% ± 10% in PLA. This was supported by the median percentage of normal cross sections/segment: 0% proximal, 0% mid, and 23% distal RCA sections plus 100% PDA and 48% PLA sections. CONCLUSIONS: Intravascular ultrasound data indicated a proximal-to-distal LAD plaque gradient; significant disease was uncommon in the distal LAD. Conversely, the proximal-to-distal RCA plaque gradient was less distinct than the LAD, although disease in the PDA was still reduced compared with proximal segments.

Definitions and methodology for the grayscale and radiofrequency intravascular ultrasound and coronary angiographic analyses.

OBJECTIVES: In a prospective study of the natural history of coronary atherosclerosis using angiography and grayscale and radiofrequency intravascular ultrasound (IVUS)-virtual histology (VH), larger plaque burden, smaller luminal area, and plaque composition thin-cap fibroatheroma emerged as independent predictors of future adverse cardiovascular events. BACKGROUND: The methodology for IVUS-VH classification for an in vivo natural history study and the prospective image mapping by angiography and grayscale and IVUS-VH have not been established. METHODS: All culprit and nonculprit lesions (defined as ≥ 30% angiographic visual diameter stenoses) were analyzed. Three epicardial vessels as well as all ≥ 1.5-mm-diameter side branches were divided into 29 CASS (Coronary Artery Surgery Study) segments. Each CASS segment was then subdivided into 1.5-mm-long subsegments, and dimensions were analyzed. All grayscale and IVUS-VH slices from the proximal 6 to 8 cm of the 3 coronary arteries were analyzed, with lesions defined as having more than 3 consecutive slices with ≥ 40% plaque burden categorized as: 1) VH thin-cap fibroatheroma; 2) thick-cap fibroatheroma; 3) pathological intimal thickening; 4) fibrotic plaque; or 5) fibrocalcific plaque. The locations of angiographic and grayscale and IVUS-VH lesions were recorded in relation to the corresponding coronary artery ostium and nearby side branches. RESULTS: The 3-year cumulative rate of major adverse cardiovascular events was 20.4%. Events were adjudicated to culprit lesions in 12.9% of patients and to nonculprit lesions in 11.6%. On multivariate analysis, nonculprit lesions associated with recurrent events were characterized by a plaque burden ≥ 70% (hazard ratio: 5.03; 95% confidence interval: 2.51 to 10.11; p < 0.0001), a minimal luminal area ≤ 4.0 mm(2) (hazard ratio: 3.21; 95% confidence interval: 1.61 to 6.42; p = 0.001), and IVUS-VH phenotype of a thin-cap fibroatheroma (hazard ratio: 3.35; 95% confidence interval: 1.77 to 6.36; p < 0.001). CONCLUSIONS: Three-vessel multimodality coronary artery imaging was feasible and allowed the identification of lesion-level predictors for future events in this natural history study.

Longitudinal distribution of plaque burden and necrotic core-rich plaques in nonculprit lesions of patients presenting with acute coronary syndromes.

OBJECTIVES: In this substudy of the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, we examined the longitudinal distribution of atherosclerotic plaque burden, virtual histology-intravascular ultrasound (VH-IVUS) characterized necrotic core (NC) content and VH-thin-cap fibroatheroma (TCFA) distribution in nonculprit lesions of patients presenting with acute coronary syndromes. BACKGROUND: Previous analyses suggested that vulnerable plaques and acute myocardial infarction may occur more frequently in the proximal than the distal coronary tree. METHODS: A total of 4,234 proximal, mid, and distal 30-mm-long segments of each epicardial coronary artery were compared with each other and to the left main coronary artery (LMCA). RESULTS: Combining IVUS data from all 3 arteries, there was a gradient in plaque burden from the proximal (42.4%) to mid (37.6%) to distal (32.6%) 30-mm-long segments (p < 0.0001). Overall, 67.4% of proximal, 41.0% of mid, and 29.7% of distal 30-mm-long segments contained at least 1 lesion (plaque burden >40%). Proportion of NC, however, was similar in the proximal and mid 30-mm-long segments of all arteries (10.3% [interquartile range (IQR): 4.8% to 16.7%] vs. 10.6% [IQR: 5.0% to 18.1%], p = 0.25), but less in the distal 30-mm-long segment (9.1% [IQR: 3.7% to 17.8%], p = 0.03 compared with the proximal segment and p = 0.003 compared with the mid segment). Overall, 17.3% of proximal, 11.5% of mid, and 9.1% of distal 30-mm-long segments had at least 1 lesion that was classified as VH-TCFA (p < 0.0001). Comparing the LMCA with the combined cohort of proximal left anterior descending, left circumflex, and right coronary artery 30-mm-long segments: 1) plaque burden was less (35.4% [IQR: 28.8% to 43.5%] vs. 40.9% [IQR: 33.3% to 48.0%], p < 0.0001); 2) fewer LMCAs contained at least 1 lesion (17.5%, p < 0.0001); 3) there was less NC (6.5% [IQR: 2.9% to 12.2%] vs. 9.3% [IQR: 4.3% to 15.9%], p < 0.0001); and 4) LMCAs rarely contained a VH-TCFA (1.8%, p < 0.0001). CONCLUSIONS: The current analysis appears to confirm that lesions that are responsible for acute coronary events (large, plaque burden-rich in NC) are somewhat more likely to be present in the proximal than the distal coronary tree, except for the LMCA.

Relationship between palpography and virtual histology in patients with acute coronary syndromes.

OBJECTIVES: The purpose of this study was to correlate adverse events at long-term follow-up in patients after an acute coronary syndrome with coronary plaque characteristics derived from simultaneous evaluation of their mechanical and compositional properties using virtual histology (intravascular ultrasound virtual histology) and palpography. BACKGROUND: Fibroatheroma is the plaque morphology with the highest risk of causing adverse cardiac events. Palpography can potentially assess the local mechanical plaque properties with the possibility of identifying fibroatheroma with the highest risk of rupture. METHODS: A total of 114 patients with acute coronary syndrome from the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) trial underwent a single ultrasound imaging investigation of their 3 coronary vessels with the co-registration of intravascular ultrasound virtual histology and palpography. Major adverse cardiac events (MACE) (cardiac death, cardiac arrest, myocardial infarction, or unstable or progressive angina) were collected up to a median follow-up of 3.4 years and adjudicated to originally treated culprit versus untreated nonculprit lesions. RESULTS: In total, 488 necrotic core-rich plaques were identified and subclassified as thin-cap fibroatheroma (n = 111), calcified thick-cap fibroatheroma (n = 213), and noncalcified thick-cap fibroatheroma (n = 164) and matched to their co-registered palpography data. A total of 16 MACE, adjudicated to untreated nonculprit lesions, were recorded at follow-up. In patients in whom MACE developed, fibroatheroma were larger (plaque area 10.0 mm(2) [range: 8.4 to 11.6 mm(2)] vs. 8.2 mm(2) [range: 7.7 to 8.8 mm(2)] (p = 0.03) compared with patients who were MACE free. By palpography, the maximum and the density strain values did not differ between the varying subtypes of fibroatheroma of patients with or without MACE during follow-up. CONCLUSIONS: In acute coronary syndromes, patients treated with stents and contemporary pharmacotherapy, palpography did not provide additional diagnostic information for the identification of fibroatheroma with a high risk of rupture and MACE during long-term follow-up. (Providing Regional Observations to Study Predictors of Events in the Coronary Tree [PROSPECT]: An Imaging Study in Patients With Unstable Atherosclerotic Lesions; NCT00180466).

Plaque composition and clinical outcomes in acute coronary syndrome patients with metabolic syndrome or diabetes.

OBJECTIVES: The goal of this study was to characterize the extent and composition of coronary atherosclerosis in patients with diabetes mellitus or the metabolic syndrome (Met Syn) presenting with acute coronary syndromes (ACS). BACKGROUND: Diabetes and Met Syn patients have increased rates of major adverse cardiac events (MACE), yet a systematic description of nonculprit lesions for these high-risk groups is incomplete. METHODS: In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, ACS patients underwent 3-vessel quantitative coronary angiography, grayscale, and radiofrequency intravascular ultrasound after successful percutaneous coronary intervention (PCI). Subsequent MACE (cardiac death or arrest, myocardial infarction, or rehospitalization for unstable or progressive angina) were adjudicated to the originally treated culprit versus untreated nonculprit lesions in 3 patient groups: 1) diabetes; 2) Met Syn; and 3) neither. Median length of follow-up was 3.4 years. RESULTS: Of 673 patients, 119 (17.7%) had diabetes and 239 (35.5%) had Met Syn. The cumulative 3-year MACE rate was 29.4% in patients with diabetes, 21.3% with Met Syn, and 17.4% with neither (p = 0.03). MACE adjudicated to untreated nonculprit lesions occurred in 18.7%, 11.7%, and 9.7% of patients, respectively (p = 0.06). Nonculprit lesions in diabetes and Met Syn patients were longer and had greater plaque burden, smaller lumen areas, with greater necrotic core and calcium content. Diabetes and Met Syn patients with future MACE had greater necrotic core and calcification compared with the normal cardiometabolic group. CONCLUSIONS: In this PCI ACS population, patients with diabetes and Met Syn had higher 3-year MACE rates. Lesion length, plaque burden, necrotic core, and calcium content were significantly greater among nonculprit lesions of patients with diabetes and Met Syn, but only necrotic core and calcium were significantly greater in the nonculprit lesions of patients with a future MACE in this exploratory analysis.

Coronary plaque composition, morphology, and outcomes in patients with and without chronic kidney disease presenting with acute coronary syndromes.

OBJECTIVES: This study sought to evaluate the impact of chronic kidney disease (CKD) on coronary atherosclerotic plaque composition, morphology, and outcomes in patients with acute coronary syndromes (ACS). BACKGROUND: CKD patients presenting with ACS are at increased risk for adverse events. Whether or not this increased risk reflects differences in coronary plaque composition remains unknown. METHODS: In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, patients presenting with ACS in whom percutaneous coronary intervention was successful underwent 3-vessel grayscale and radiofrequency intravascular ultrasound imaging. Lesions were prospectively characterized, and patients were followed for a median of 3.4 years. We conducted a patient-level and lesion-level analysis of study participants by comparing intravascular ultrasound parameters of untreated nonculprit lesions in patients with and without CKD. RESULTS: Patients with CKD (n = 73, 11.3%) were older, more often female and diabetic compared to those without CKD (n = 573). Nonculprit lesions in patients with (n = 280) versus without (n = 2,390) CKD were more likely to have plaque burden ≥ 70% (11.8% vs. 8.5%, p = 0.05) and minimal luminal area ≤ 4.0 mm(2) (25.9% vs. 19.2%, p = 0.005). The percentage of plaque comprised of necrotic core (15.0% vs. 13.0%, p = 0.0001) and dense calcium (8.2% vs. 6.4%, p < 0.0001) was higher while fibrous tissue (57.7% vs. 59.8%, p < 0.0001) was lower in CKD versus non-CKD lesions. The 3-year composite rate of cardiac death, cardiac arrest, or myocardial infarction (15.1% vs. 3.3%, p < 0.0001) was significantly higher in patients with than in those without CKD, although there were no differences in the rates of events adjudicated to nonculprit lesions. CONCLUSIONS: Following percutaneous coronary intervention of all culprit lesions in ACS, patients with versus without CKD have more extensive and severe atherosclerosis remaining in their coronary tree with plaque composed of greater necrotic core and less fibrous tissue. These influences resulted in nonsignificantly different rates of non-culprit lesion-related adverse events, although cardiac death, arrest, or myocardial infarction were more common in patients with CKD.

Characteristics and clinical significance of angiographically mild lesions in acute coronary syndromes.

OBJECTIVES: The aim of this study was to assess whether residual nonculprit (NC) lesions, defined as visual diameter stenosis ≥ 30% after successful percutaneous coronary intervention, affect the rate of future events in patients with acute coronary syndromes. BACKGROUND: In patients with acute coronary syndromes, approximately one-half of recurrent events after percutaneous coronary intervention arise from untreated lesions. METHODS: Patients enrolled in PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) were divided into 3 groups: those with no NC lesions, 1 NC lesion, or ≥ 2 NC lesions. Time to events for major adverse cardiac events was estimated up to 3 years. RESULTS: Among 697 patients, 13.3% had no NC lesions, 19.7% had 1 NC lesion, and 67.0% had ≥ 2 NC lesions. The median diameter stenoses of the NC lesions in the latter 2 groups were 36.7% (interquartile range: 31.0% to 43.4%) and 37.4% (interquartile range: 32.0% to 46.5%), respectively (p = 0.22). At least 1 thin-cap fibroatheroma was present in one-half the patients in each group. At 3 years, the incidence of major adverse cardiac events was 8.5%, 15.2%, and 24.3%, respectively (p = 0.0009). NC lesion-related events occurred in 0%, 5.0%, and 15.9% of patients, respectively (p < 0.0001). Of 105 NC lesion-related clinical events occurring during follow-up, 73 (69.5%) originated from angiographically evident baseline NC lesions (of which 36 had diameter stenosis >50%), while the other 32 arose from normal or near normal segments. CONCLUSIONS: Residual NC lesions are common after percutaneous coronary intervention for acute coronary syndromes and portend a higher rate of recurrent ischemic events within 3 years, especially when angiographically more severe. Conversely, the absence of NC lesions by angiography is highly predictive of freedom from events not related to the originally treated culprit lesion(s).

Residual plaque burden in patients with acute coronary syndromes after successful percutaneous coronary intervention.

OBJECTIVES: The aim of this study was to characterize and evaluate the clinical impact of untreated atherosclerotic disease after percutaneous coronary intervention (PCI) in patients with acute coronary syndromes (ACS). BACKGROUND: Residual atherosclerotic disease after successful PCI may predispose future major adverse cardiovascular events (MACE). Compared with intravascular ultrasound (IVUS), angiography underestimates the presence and severity of coronary artery disease. METHODS: Following successful PCI of all clinically significant lesions in 697 patients with ACS, 3-vessel grayscale and radiofrequency IVUS was performed. Lesions were prospectively characterized, and patients were followed for a median of 3.4 years. A total of 3,229 untreated lesions (4.89 ± 1.98 lesions/patient) were identified by IVUS, with mean plaque burden (PB) of 49.6 ± 4.2%. RESULTS: By angiography these nonculprit lesions were mild, with mean diameter stenosis of 38.9 ± 15.3%. At least 1 lesion with a PB ≥70% (PB70 lesion) was found in 220 (33%) patients. By multivariable analysis, a history of prior PCI and angiographic 3-vessel disease were independent predictors of PB70 lesions. Patients with PB70 lesions had greater total percent plaque volume, normalized PB, fibroatheromas, thin-cap fibroatheromas, and normalized volumes of necrotic core and dense calcium. Patients with PB70 lesions had greater 3-year rates of MACE due to untreated nonculprit lesions (20.8% vs. 7.7%, p < 0.0001). Among imaged nonculprit lesions, the proportion of PB70 lesions causing MACE was significantly greater than non-PB70 lesions (8.7% vs. 1.0%, p < 0.0001). CONCLUSIONS: After successful PCI of all angiographically significant lesions, overall untreated atherosclerotic burden remains high, and PB70 lesions are frequently present in the proximal and mid-coronary tree. Patients with PB70 lesions have greater atherosclerosis throughout the coronary tree, have more thin-cap fibroatheromas, and are at increased risk for future cardiovascular events. ( PROSPECT: An Imaging Study in Patients With Unstable Atherosclerotic Lesions; NCT00180466).

Adverse cardiovascular events arising from atherosclerotic lesions with and without angiographic disease progression.

OBJECTIVES: The aim of this study was to use angiography and grayscale and intravascular ultrasound-virtual histology to assess coronary lesions that caused events during a median follow-up period of 3.4 years. BACKGROUND: Vulnerable plaque-related events are assumed to be the result of substantial progression of insignificant lesions. METHODS: In the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study, 697 patients with acute coronary syndromes underwent treatment of all culprit lesions followed by 3-vessel imaging to assess the natural history of culprit and untreated nonculprit (NC) lesions. Future adverse cardiovascular events adjudicated to NC lesions were divided into those with versus without substantial lesion progression (SLP) (≥ 20% angiographic diameter stenosis increase). RESULTS: NC lesion events occurred in 72 patients, 44 (61%) with and 28 (39%) without SLP. Myocardial infarctions (n = 6) occurred only in patients with SLP. Conversely, patients without SLP presented only with unstable or increasing angina requiring rehospitalization. Lesions with versus without SLP occurred later (median time to event 401 vs. 223 days, p = 0.07); were less severe at baseline (median diameter stenosis 26.4% vs. 53.8%, p < 0.0001) but more severe at the time of the event (mean diameter stenosis 73.8% vs. 56%, p < 0.0001); and had comparable baseline median plaque burden (68.7% vs. 70.1%, p = 0.17), minimum luminal area (3.7 vs. 4.0 mm(2), p = 0.60), and intravascular ultrasound-virtual histology phenotype (83.3% vs. 90.9%, p = 0.68; classified as fibroatheromas at baseline). CONCLUSIONS: NC lesions responsible for future cardiovascular events showed angiographic increase during 3.4 years of follow-up, whereas SLP underlay many but not all of them. NC events due to lesions with SLP were angiographically less severe and presented with a delayed time course but were otherwise indistinguishable from NC events that were not associated with SLP.

A prospective natural-history study of coronary atherosclerosis.

BACKGROUND: Atherosclerotic plaques that lead to acute coronary syndromes often occur at sites of angiographically mild coronary-artery stenosis. Lesion-related risk factors for such events are poorly understood. METHODS: In a prospective study, 697 patients with acute coronary syndromes underwent three-vessel coronary angiography and gray-scale and radiofrequency intravascular ultrasonographic imaging after percutaneous coronary intervention. Subsequent major adverse cardiovascular events (death from cardiac causes, cardiac arrest, myocardial infarction, or rehospitalization due to unstable or progressive angina) were adjudicated to be related to either originally treated (culprit) lesions or untreated (nonculprit) lesions. The median follow-up period was 3.4 years. RESULTS: The 3-year cumulative rate of major adverse cardiovascular events was 20.4%. Events were adjudicated to be related to culprit lesions in 12.9% of patients and to nonculprit lesions in 11.6%. Most nonculprit lesions responsible for follow-up events were angiographically mild at baseline (mean [±SD] diameter stenosis, 32.3±20.6%). However, on multivariate analysis, nonculprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of 70% or greater (hazard ratio, 5.03; 95% confidence interval [CI], 2.51 to 10.11; P<0.001) or a minimal luminal area of 4.0 mm(2) or less (hazard ratio, 3.21; 95% CI, 1.61 to 6.42; P=0.001) or to be classified on the basis of radiofrequency intravascular ultrasonography as thin-cap fibroatheromas (hazard ratio, 3.35; 95% CI, 1.77 to 6.36; P<0.001). CONCLUSIONS: In patients who presented with an acute coronary syndrome and underwent percutaneous coronary intervention, major adverse cardiovascular events occurring during follow-up were equally attributable to recurrence at the site of culprit lesions and to nonculprit lesions. Although nonculprit lesions that were responsible for unanticipated events were frequently angiographically mild, most were thin-cap fibroatheromas or were characterized by a large plaque burden, a small luminal area, or some combination of these characteristics, as determined by gray-scale and radiofrequency intravascular ultrasonography. (Funded by Abbott Vascular and Volcano; ClinicalTrials.gov number, NCT00180466.).

Intravascular ultrasound classification of plaque distribution in left main coronary artery bifurcations: where is the plaque really located?

BACKGROUND: Angiographic classifications of the location and severity of disease in the main vessel and side branch of coronary artery bifurcations have been proposed and applied to distal left main coronary artery (LMCA) bifurcation. METHODS AND RESULTS: We reviewed 140 angiograms of distal LMCA and ostial left anterior descending (LAD) and left circumflex (LCX) artery lesions with preintervention intravascular ultrasound (IVUS) of both the LAD and LCX arteries as well as the LMCA. Of 140 patients, 92.9% had at least 1 cross section with > or =40% IVUS plaque burden versus 57.2% of patients with an angiographic diameter stenosis > or =50%. Contrary to angiographic classifications, IVUS showed that bifurcation disease was rarely focal and that both sides of the flow divider were always disease-free. Continuous plaque from the LMCA into the proximal LAD artery was seen in 90%, from the LMCA into the LCX artery in 66.4%, and from the LMCA into both the LAD and LCX arteries in 62%. Plaque localized to either the LAD or LCX ostium and not involving the distal LMCA was seen in only 9.3% of LAD arteries and 17.1% of LCX arteries. Plaque distribution was not influenced by the LAD/LCX angiographic angle, lesion severity, LMCA length, or remodeling. We proposed an IVUS classification for bifurcation lesions illustrating longitudinal and circumferential spatial plaque distribution. CONCLUSIONS: Angiographic classification of LMCA bifurcation lesions is rarely accurate. IVUS shows that the carina is always spared and that the disease is diffuse rather than focal.

Is accurate intravascular ultrasound evaluation of the left circumflex ostium from a left anterior descending to left main pullback possible?

Treatment of left main coronary artery bifurcation lesions might depend on the ostial left circumflex (LC) or ostial left anterior descending (LAD) disease severity. We sought to evaluate whether intravascular ultrasound assessment of the side branch ostium requires direct imaging or is accurate from the main vessel. Our retrospective analysis included 126 patients with left main coronary artery bifurcation disease (plaque burden > or =40% by intravascular ultrasound scanning). We analyzed pullbacks from the LAD and the LC. First, during the main vessel pullback (ie, from the LAD), we evaluated the side branch ostium (ie, of the LC). Second, we compared this oblique view with the direct ostial measurements during LC pullback. Finally, we repeated this process, imaging the ostial LAD from the LC. From the LAD, the oblique LC ostial lumen diameter was 3.0 +/- 0.8 mm compared to the directly measured lumen diameter of 2.9 +/- 0.6 mm. From the LC, the oblique LAD ostial lumen diameter was 2.9 +/- 1.1 mm compared to the directly measured lumen diameter of 2.8 +/- 0.5 mm. However, Bland-Altman plots showed significant variation in the oblique versus direct comparisons. The 95% limits of agreement ranged from -1.84 to 1.14 mm (mean difference -0.35, SD 0.75) for the LAD and -1.69 to 1.22 mm (mean difference -0.23, SD 0.73) for the LC. The "oblique view" detection of any plaque in the side branch predicted 40% or 70% plaque burden with good sensitivity but poor specificity. In conclusion, intravascular ultrasound evaluation of a side branch ostium from the main vessel is only moderately reliable, especially for distal left main coronary artery lesions. For an accurate assessment of the side branch ostium, direct imaging is necessary.