Optical Coherence Tomography-Guided versus Angiography-Guided PCI.

BACKGROUND: Data regarding clinical outcomes after optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) as compared with angiography-guided PCI are limited. METHODS: In this prospective, randomized, single-blind trial, we randomly assigned patients with medication-treated diabetes or complex coronary-artery lesions to undergo OCT-guided PCI or angiography-guided PCI. A final blinded OCT procedure was performed in patients in the angiography group. The two primary efficacy end points were the minimum stent area after PCI as assessed with OCT and target-vessel failure at 2 years, defined as a composite of death from cardiac causes, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization. Safety was also assessed. RESULTS: The trial was conducted at 80 sites in 18 countries. A total of 2487 patients underwent randomization: 1233 patients were assigned to undergo OCT-guided PCI, and 1254 to undergo angiography-guided PCI. The minimum stent area after PCI was 5.72±2.04 mm2 in the OCT group and 5.36±1.87 mm2 in the angiography group (mean difference, 0.36 mm2; 95% confidence interval [CI], 0.21 to 0.51; P<0.001). Target-vessel failure within 2 years occurred in 88 patients in the OCT group and in 99 patients in the angiography group (Kaplan-Meier estimates, 7.4% and 8.2%, respectively; hazard ratio, 0.90; 95% CI, 0.67 to 1.19; P = 0.45). OCT-related adverse events occurred in 1 patient in the OCT group and in 2 patients in the angiography group. Stent thrombosis within 2 years occurred in 6 patients (0.5%) in the OCT group and in 17 patients (1.4%) in the angiography group. CONCLUSIONS: Among patients undergoing PCI, OCT guidance resulted in a larger minimum stent area than angiography guidance, but there was no apparent between-group difference in the percentage of patients with target-vessel failure at 2 years. (Funded by Abbott; ILUMIEN IV: OPTIMAL PCI ClinicalTrials.gov number, NCT03507777.).

Optical Coherence Tomography-Based Modeling of Stent Deployment in Heavily Calcified Coronary Lesion.

In this work, a heavily calcified coronary artery model was reconstructed from optical coherence tomography (OCT) images to investigate the impact of calcification characteristics on stenting outcomes. The calcification was quantified at various cross sections in terms of angle, maximum thickness, and area. The stent deployment procedure, including the crimping, expansion, and recoil, was implemented. The influence of calcification characteristics on stent expansion, malapposition, and lesion mechanics was characterized. Results have shown that the minimal lumen area following stenting occurred at the cross section with the greatest calcification angle. The calcification angle constricted the stretchability of the lesion and thus resulted in a small lumen area. The maximum principal strain and von Mises stress distribution patterns in both the fibrotic tissue and artery were consistent with the calcification profiles. The radially projected region of the calcification tends to have less strain and stress. The peak strain and stress of the fibrotic tissue occurred near the interface with the calcification. It is also the region with a high risk of tissue dissection and strut malapposition. In addition, the superficial calcification with a large angle aggregated the malapposition at the middle of the calcification arc. These detailed mechanistic quantifications could be used to provide a fundamental understanding of the role of calcification in stent expansions, as well as to exploit their potential for enhanced pre- and post-stenting strategies.

Impact of residual coronary atherosclerosis on transfemoral transcatheter aortic valve replacement.

OBJECTIVES: This study reports on the clinical effects of complete vs incompletely revascularized coronary artery disease on transcatheter aortic valve replacement (TAVR). BACKGROUND: There is a high prevalence of active coronary artery disease (CAD) in patients undergoing TAVR but preemptive revascularization remains controversial. METHODS: Patients were categorized into three cohorts: complete revascularization (CR), incomplete revascularization of a major epicardial artery (IR Major), and incomplete revascularization of a minor epicardial artery only (IR Minor). When feasible, SYNTAX scoring was performed for exploratory analysis. Analyses were performed using Cox proportional hazard models and Kaplan-Meier method. RESULTS: A total of 323 patients with active CAD were included. Adjusted outcomes showed that patients with IR Major had increased incidence of acute myocardial infarction (AMI) or revascularization compared with those in the CR cohort (HR 3.72, P = 0.048). No difference was noted in all-cause mortality or all-cause readmission rates. Exploratory secondary analysis with residual SYNTAX scores showed a significant interaction between disease burden and AMI/revascularization, as well as all-cause readmission. All-cause mortality remained unaffected based on residual SYNTAX scores. CONCLUSIONS: This is a retrospective single-center study reporting on pre-TAVR revascularization outcomes in patients with active CAD. In this analysis, we found that patients undergoing TAVR benefited from achieving complete revascularization to abate future incidence of AMI/revascularization. Despite this finding, all-cause mortality remained unaffected. Future efforts should focus on the role of functional assessment of the coronaries, as well as the long-term effects of complete revascularization in a larger patient cohort.

Impact of Calcium Quantifications on Stent Expansions.

Severely calcified plaque is of great concern when planning and implementing a stenting intervention. In this work, computational models were developed to investigate the influence of calcium characteristics on stenting outcomes. The commonly used clinical measurements of calcium (i.e., the arc angle, maximum thickness, length, and volume) were varied to estimate stenting outcomes in terms of lumen gain, stent underexpansion, strut malapposition, and stress or strain distributions of the stenotic lesion. Results have shown that stenting outcomes were most sensitive to the arc angle of the calcium. A thick calcium with a large arc angle resulted in poor stenting outcomes, such as severe stent underexpansion, D-shaped lumen, increased strut malapposition, and large stresses or strains in the plaque. This was attributed to the circumferential stretch of the tissue. Specifically, the noncalcium component was stretched significantly more than the calcium. The circumferential stretch ratios of calcium and noncalcium component were approximately 1.44 and 2.35, respectively, regardless of calcium characteristics. In addition, the peak stress or strain within the artery and noncalcium component of the plaque occurred at the area adjacent to calcium edges (i.e., the interface between the calcium and the noncalcium component) coincident with the location of peak malapposition. It is worth noting that calcium played a protective role for the artery underneath, which was at the expense of the overstretch and stress concentrations in the other portion of the artery. These detailed mechanistic quantifications could be used to provide a fundamental understanding of the impact of calcium quantifications on stent expansions, as well as to exploit their potential for a better preclinical strategy.

Safety of shorter length of hospital stay for patients undergoing minimalist transcatheter aortic valve replacement.

OBJECTIVE: Determine the feasibility and predictors of early discharge after minimalist transcatheter aortic valve replacement (TAVR). BACKGROUND: Duration of hospitalization has a direct impact on overall cost of care, but the clinical impact of length of stay (LOS) in patients undergoing minimalist TAVR remains unclear. METHODS: We studied 268 patients who underwent minimalist TAVR. Short LOS (sLOS) was defined as post-procedural LOS ≤ 3 days and observed in 163 patients. Prolonged LOS (pLOS) was observed in 105 patients. Propensity score matching based on 39 variables yielded 54 pairs of patients in each group. We analyzed 30-day mortality, 30-day re-hospitalization and long-term survival data. Multivariate regression models were used to define predictors of sLOS. RESULTS: Thirty-day mortality was 0% versus 5.5% in the sLOS and pLOS groups, respectively (P = 0.08). Incidence of re-hospitalization was higher in pLOS (13% vs. 3.7%). sLOS was associated with lower odds ratio of minor vascular complication (OR 0.1 [95% CI: 0.01, 0.75], P = 0.05), any bleeding (OR 0.35 [95% CI: 0.14, 0.87], P = 0.02), blood transfusion (OR 0.27 [95% CI: 0.08, 0.81], P = 0.02), and new pacemaker implantation (OR 0.23 [95% CI: 0.1, 0.53], P < 0.001). Discharge to home had a significantly higher odd ratio for sLOS (OR 8.67 [95% CI: 3.59, 23.11], P < 0.001). CONCLUSION: In appropriately selected patients, sLOS following minimalist TAVR approach in an experienced and high volume center is feasible and safe. Implementing such a strategy may reduce medical costs with the potential clinical benefit of early re-habilitation for the elderly TAVR population.

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.

Evaluating the quality of implantation of percutaneous ventricular restoration device (Parachute®) by cardiac computed tomography.

BACKGROUND: The Parachute is a novel percutaneously implanted ventricular partitioning device (VPD) that has emerged as a safe and feasible treatment option for patients with heart failure following anterior wall myocardial infarction. VPD efficacy is likely dependent on optimal device placement, but to date there are no published data examining the effect of device positioning on patient outcomes. METHODS AND RESULTS: We retrospectively identified 32 patients successfully implanted with the Parachute device, all of whom underwent cardiac computed tomography (CCT) at baseline and after 6 months of follow-up. Patients were divided into two groups based on self-reported improvement in New York Heart Association (NYHA) functional class: "not improved NYHA" (n = 12) and "improved NYHA" (n = 20). There were significant differences between both groups with regard to device positioning on follow-up CCT. Compared to patients with "improved NYHA," patients with "not improved NYHA" had longer distances from device foot to left ventricular apex (8.0 ± 4.9 vs. 2.9 ± 4.6 mm; P = 0.01), and higher lateral angles (18.0 ± 14 vs. 9.1 ± 6.8 degrees; P = 0.02), respectively. There was no significant difference between the two groups in landing zone (45.4 ± 7. vs. 45.1 ± 6.9 mm; P = 0.92) and inferior angle (14.0 ± 11.9 vs. 14.3 ± 10.1 degrees; P = 0.95). There was a numerically larger malapposition area in the "not improved NYHA" group (5.1 ± 4.5 vs. 3.2 ± 2.2 cm2; P = 0.12). CONCLUSION: Quality of Parachute implant impacted clinical outcome, these findings should be applied prospectively in helping operators to achieve optimal implant. © 2016 Wiley Periodicals, Inc.

Characteristic Features on Morphologic and Topographic Findings of Pulmonary Vein Orifices in Transition From Diastolic Dysfunction to Heart Failure: A Computerized Tomography Study.

BACKGROUND: Diastolic dysfunction (DD), a precursor to clinical heart failure (HF), has traditionally been evaluated by means of echocardiography. Data regarding morphologic descriptions of pulmonary vein (PV) orifices in transition from DD to HF have been lacking. METHODS AND RESULTS: We retrospectively studied 124 subjects with computerized tomography (CT)-derived PV parameters and echocardiography-derived diastolic indices. We categorized our subjects as 1) non-DD, 2) DD, or 3) heart failure with preserved ejection fraction (HFpEF) and observed a graded enlargement for 4 PV orifice areas across these groups. Positive linear relationship between the 4 PV orifice areas, echocardiography-derived mean pulmonary capillary wedge pressure (PCWP), and velocity of propagation (VP) were observed. Finally, maximum areas of left superior pulmonary vein (LSPV) and left inferior pulmonary vein (LIPV) significantly increased clinical diagnosis of HFpEF (likelihood-ratio χ(2): from 42.92 to 50.75 and 54.67 for LSPV and LIPV, respectively) when superimposed on left ventricular mass index, PCWP, and left atrial volume. CONCLUSIONS: PV size measurements with the use of CT are feasible and further aid in diseases discrimination between preclinical DD and those progressed into HF, even with preserved global pumping. Our data suggest that CT-based PV measures may help to identify subjects at risk for HF.

Cardiac computed tomography assessment of the near term impact of percutaneous ventricular restoration therapy (parachute(®) ) on mitral valve geometry.

OBJECTIVES: The aim of current study is to assess the near term impact of percutaneous ventricular restoration therapy (PVR), Parachute(®) on mitral valve (MV) geometry by cardiac computed tomography (CCT). BACKGROUND: Recent data demonstrates the feasibility of PVR for treatment of post anterior myocardial infarction (MI) heart failure. Little is known, however, about the interaction of the device and left ventricular structures, particularly the MV apparatus. METHODS: This is a retrospective Core Laboratory analysis of Parachute Trials' CCT data. Patients with paired (before and after Parachute implant) CCT acquisitions were included into analysis. MV geometric parameters were measured. RESULTS: Thirty-three patients were included in the analysis. The mean time of follow-up CCT post procedure was 188 ± 52 days. There were significant reduction in tenting height (A1P1: -1.70 ± 1.89 mm, -17.40 ± 20.20%; A2P2: -1.43 ± 1.89 mm, -12.10 ± 15.00%; A3P3: -1.54 ± 1.58 mm, -15.50 ± 15.20%, P < 0.001), tenting volume (-0.93 ± 0.60 mm3, -22.00 ± 11.40%, P < 0.001), systolic interpapillary muscle distance (-2.22 ± 2.11 mm, -7.51 ± 7.23%, P < 0.001) and diastolic interpapillary muscle distance (-3.14 ± 2.20 mm, -8.46 ± 5.73%, P < 0.001) post PVR. CONCLUSIONS: In post anterior MI heart failure patients, PVR has favorable near term impact on MV geometry as assessed by CCT. © 2015 Wiley Periodicals, Inc.

Dextran or Saline Can Replace Contrast for Intravascular Optical Coherence Tomography in Lower Extremity Arteries.

PURPOSE: To examine the hypothesis that alternative flush media could be used for lower extremity optical coherence tomography (OCT) imaging in long lesions that would normally require excessive use of contrast. METHODS: The OPTical Imaging Measurement of Intravascular Solution Efficacy (OPTIMISE) trial was a single-center, prospective study (ClinicalTrials.gov identifier NCT01743872) that enrolled 23 patients (mean age 68±11 years; 14 men) undergoing endovascular intervention involving the superficial femoral artery. Four flush media (heparinized saline, dextran, carbon dioxide, and contrast) were used in succession in random order for each image pullback. Quality was defined as ≥270° visualization of vessel wall layers from each axial image. Mean proportions (± standard deviation) of image quality for each flush medium were assessed using 1-way analysis of variance and are reported with the 95% confidence intervals (CI). RESULTS: Four OCT catheters failed, leaving 19 patients who completed the OCT imaging protocol; from this cohort, 51 highest quality runs were selected for analysis. Average vessel diameter was 3.99±1.01 mm. OCT imaging allowed 10- to 15-µm resolution of the lumen border, with diminishing quality as vessel diameter increased. Plaque characterization revealed fibrotic lesions. Mean proportions of image quality were dextran 87.2%±12% (95% CI 0.81 to 0.94), heparinized saline 74.3%±24.8% (95% CI 0.66 to 0.93), contrast 70.1%±30.5% (95% CI 0.52 to 0.88), and carbon dioxide 10.0%±10.4% (95% CI 0.00 to 0.26). Dextran, saline, and contrast provided better quality than carbon dioxide (p<0.001). CONCLUSION: OCT is feasible in peripheral vessels <5 mm in diameter. Dextran or saline flush media can allow lesion characterization, avoiding iodinated contrast. Carbon dioxide is inadequate for peripheral OCT imaging. Axial imaging may aid in enhancing durability of peripheral endovascular interventions.

Differences determined by optical coherence tomography volumetric analysis in non-culprit lesion morphology and inflammation in ST-segment elevation myocardial infarction and stable angina pectoris patients.

BACKGROUND: While the current methodology for determining fibrous cap (FC) thickness of lipid plaques is based on manual measurements of arbitrary points, which could lead to high variability and decreased accuracy, it ignores the three-dimensional (3-D) morphology of coronary artery disease. OBJECTIVE: To compare, utilizing optical coherence tomography (OCT) assessments, volumetric quantification of FC, and macrophage detection using both visual assessment and automated image processing algorithms in non-culprit lesions of STEMI and stable angina pectoris (SAP) patients. METHODS: Lipid plaques were selected from 67 consecutive patients (1 artery/patient). FC was manually delineated by a computer-aided method and automatically classified into three thickness categories: FC < 65 µm (i.e., thin-cap fibroatheroma [TCFA]), 65-150 µm, and >150 µm. Minimum thickness, absolute categorical surface area, and fractional luminal area of FC were analyzed. Automated detection and quantification of macrophage was performed within the segmented FC. RESULTS: A total of 5,503 cross-sections were analyzed. STEMI patients when compared with SAP patients had more absolute categorical surface area for TCFA (0.43 ± 0.45 mm(2) vs. 0.15 ± 0.25 mm(2) ; P = 0.011), thinner minimum FC thickness (31.63 ± 17.09 µm vs. 47.27 ± 26.56 µm, P = 0.012), greater fractional luminal area for TCFA (1.65 ± 1.56% vs. 0.74 ± 1.2%, P = 0.046), and greater macrophage index (0.0217 ± 0.0081% vs. 0.0153 ± 0.0045%, respectively, P < 0.01). CONCLUSION: The novel OCT-based 3-D quantification of the FC and macrophage demonstrated thinner FC thickness and larger areas of TCFA coupled with more inflammation in non-culprit sites of STEMI compared with SAP.

Comparison of scanning electron microscopy and optical coherence tomography for imaging of coronary bifurcation stents.

BACKGROUND: Optical coherence tomography (OCT) is a new intracoronary imaging modality that has excellent resolution and image quality and has been used to image neointimal coverage after stent implantation. OCT has been compared to histologic, intravascular ultrasound, and scanning electron microscopy (SEM) studies. However, OCT has not been compared with SEM for imaging stent coverage over side branches. OBJECTIVE: The aim of this study was to compare OCT with SEM in imaging neointimal coverage over stent struts bridging coronary side-branch ostia. METHODS: Using a balloon-overstretch in-stent restenosis model, we deployed 38 everolimus-eluting stents across coronary bifurcations in nine pigs. We performed OCT immediately after stenting and 4 weeks later; SEM was performed after euthanizing the pigs. OCT images of each stent were compared to the corresponding SEM image. RESULTS: We analyzed OCT frames (n=111) for strut-level neointimal coverage and compared them to corresponding SEM images. The concordance correlation coefficient was 0.809 (95%CI; 0.734-0.864) and 0.951 (95%CI; 0.930-0.966) for covered and uncovered struts, respectively. CONCLUSIONS: In a non-atherosclerotic pig model, we showed strong agreement between OCT and SEM in imaging coverage of stent struts bridging side-branch ostia.

Longitudinal Geographic Miss (LGM) in Robotic Assisted Versus Manual Percutaneous Coronary Interventions.

OBJECTIVES: To evaluate the impact of robotic-assisted percutaneous coronary intervention (RA-PCI) versus manual PCI (M-PCI) on the incidence of Longitudinal Geographic Miss (LGM). BACKGROUND: The safety and feasibility of RA-PCI has been established in preclinical animal trials and human clinical trials. Patients with LGM have been shown to have worse clinical outcomes including significantly increased incidences of MACE. METHODS: Patients with significant coronary artery disease underwent RA-PCI in the PRECISE study (n=164) and standard M-PCI in the STLLR trial (n = 1,509). Longitudinal geographic miss was defined as cases where the entire length of the injured or stenotic segment was not fully covered by the total length of the stent. The incidence of LGM was compared between RA-PCI and M-PCI cohorts. RESULTS: The RA-PCI cohort had a significantly greater prevalence of previous MI, previous coronary revascularization, and unstable angina. The robotic cohort exhibited a lower incidence of LGM when compared to the M-PCI patients, 12.2% to 43.1%, respectively (P < 0.0001). To account for the differences in baseline characteristics between the two studies, a propensity score analysis was conducted. The propensity modeling showed similar rates of LGM in both a larger group of patients that met key PRECISE study inclusion/exclusion criteria adjusted for propensity score (9.3% vs 55.0%; P < 0.0001) and in a smaller, matched on propensity score, subset of patients (10.3% vs 64.1%; P < 0.0001). CONCLUSION: Robotic-assisted PCI had significantly lower incidence of LGM compared to standard M-PCI. Reducing LGM potentially improves long-term clinical outcomes through reduction in MACE.

The association among MDCT-derived three-dimensional visceral adiposities on cardiac diastology and dyssynchrony in asymptomatic population.

BACKGROUND: Visceral adipose tissue, a biologically active fat depot, has been proposed as a reliable marker for visceral adiposity and metabolic abnormalities. Effects of such adiposity on LV diastolic function and dyssynchrony remained largely unknown. METHODS: We assessed pericardial fat (PCF) and thoracic peri-aortic fat (TPAF) by three-dimensional (3D) volume-vender multi-detector computed tomography (MDCT) (Aquarius 3D Workstation, TeraRecon, San Mateo, CA, USA). Echo-derived diastolic parameters and tissue Doppler imaging (TDI) defined mitral annular systolic (S'), early diastolic (E') velocities as well as LV filling (E/E') were all obtained. Intra-ventricular systolic (Sys-D) and diastolic (Dias-D) dyssynchrony were assessed by TDI method. RESULTS: A total of 318 asymptomatic subjects (mean age: 53.5 years, 36.8 % female) were eligible in this study. Greater PCF and TPAF were both associated with unfavorable diastolic indices and higher diastolic dyssynchrony (all p < 0.05). These associations remained relatively unchanged in multi-variate models. PCF and TPAF set at 81.68 & 8.11 ml yielded the largest sensitivity and specificity (78.6 and 60 % for PCF, 75 and 66.6 % for TPAF, respectively) in predicting abnormally high LV diastolic dyssynchrony, which was defined as Dias-D≧55 ms. CONCLUSION: Increasing visceral adiposity may be associated with adverse effects on myocardium, primarily featured by worse diastolic function and greater degree of dyssynchrony.

Qualitative and semi-quantitative evaluation of myocardium perfusion with 3 T stress cardiac MRI.

BACKGROUND: 3 T MRI has been adopted by some centers as the primary choice for assessment of myocardial perfusion over conventional 1.5 T MRI. However, there is no data published on the potential additional value of incorporating semi-quantitative data from 3 T MRI. This study sought to determine the performance of qualitative 3 T stress magnetic resonance myocardial perfusion imaging (3 T-MRMPI) and the potential incremental benefit of using a semi-quantitative perfusion technique in patients with suspected coronary artery disease (CAD). METHODS: Fifty eight patients (41 men; mean age: 59 years) referred for elective diagnostic angiography underwent stress 3 T MRMPI with a 32-channel cardiac receiver coil. The MR protocol included gadolinium-enhanced stress first-pass perfusion (0.56 mg/kg, dipyridamole), rest perfusion, and delayed enhancement (DE). Visual analysis was performed in two steps. Ischemia was defined as a territory with perfusion defect at stress study but no DE or a territory with DE but additional peri-infarcted perfusion defect at stress study. Semi-quantitative analysis was calculated by using the upslope of the signal intensity-time curve during the first pass of contrast medium during dipyridamole stress and at rest. ROC analysis was used to determine the MPRI threshold that maximized sensitivity. Quantitative coronary angiography served as the reference standard with significant stenosis defined as >70 % diameter stenosis. Diagnostic performance was determined on a per-patient and per-vessel basis. RESULTS: Qualitative assessment had an overall sensitivity and specificity for detecting significant stenoses of 77 % and 80 %, respectively. By adding MPRI analysis, in cases with negative qualitative assessment, the overall sensitivity increased to 83 %. The impact of MPRI differed depending on the territory; with the sensitivity for detection of left circumflex (LCx) stenosis improving the most after semi-quantification analysis, (66 % versus 83 %). CONCLUSIONS: Pure qualitative assessment of 3 T MRI had acceptable performance in detecting severe CAD. There is no overall benefit of incorporating semi-quantitative data; however a higher sensitivity can be obtained by adding MPRI, especially in the detection of LCx lesions.

The use of dextran and carbon dioxide for optical coherence tomography in the superficial femoral artery.

The following case report describes using carbon dioxide (CO2) as contrast media for intravascular optical coherence tomography (OCT) imaging in the superficial femoral artery. For initial OCT imaging, 20 mL of iodinated contrast was used during automated pullback. This was followed by 20 mL of hand-injected dextran 40 in normal saline, and finally hand-injected 50 mL of CO2. CO2 gave comparable erythrocyte clearance and imaging quality compared with dextran and iodinated contrast. To our knowledge, this is the first reported case using both dextran and CO2 with OCT imaging of the superficial femoral artery. Using CO2 is a viable option in patients with contraindications to contrast or dextran use.

Diagnostic accuracy of intravascular ultrasound-derived minimal lumen area compared with fractional flow reserve--meta-analysis: pooled accuracy of IVUS luminal area versus FFR.

INTRODUCTION: Although intravascular ultrasound minimal luminal area (IVUS-MLA) is one of many anatomic determinants of lesion severity, it has been proposed as an alternative to fractional flow reserve (FFR) to assess severity of coronary artery disease. OBJECTIVE: Pool the diagnostic performance of IVUS-MLA and determine its overall accuracy to predict the functional significance of coronary disease using FFR (0.75 or 0.80) as the gold standard. METHODS: Studies comparing IVUS and FFR to establish the best MLA cutoff value that correlates with significant coronary stenosis were reviewed from a Medline search using the terms "fractional flow reserve" and "ultrasound." DerSimonian Laird method was applied to obtain pooled accuracy. RESULTS: Eleven clinical trials, including two left main (LM) trials (total N = 1,759 patients, 1,953 lesions) were included. The weighted overall mean MLA cutoff was 2.61 mm(2) in non-LM trials and 5.35 mm(2) in LM trials. For non-LM lesions, the pooled sensitivity of MLA was 0.79 (95% CI = 0.76-0.83) and specificity was 0.65 (95% CI = 0.62-0.67). Positive likelihood ratio (LR) was 2.26 (95% CI = 1.98-2.57) and LR- was 0.32 (95% CI = 0.24-0.44). Area under the summary receiver operator curve for all trials was 0.848. Pooled LM trials had better accuracy: sensitivity = 0.90, specificity = 0.90, LR+ = 8.79, and LR- = 0.120. CONCLUSION: Given its limited pooled accuracy, IVUS-MLA's impact on clinical decision in this scenario is low and may lead to misclassification in up to 20% of the lesions. Pooled analysis points toward lower MLA cutoffs than the ones used in current practice.

Early use of intrapartum intra-aortic balloon pump support for haemodynamic stabilization of peripartum and anthracycline-induced cardiomyopathy: a case report.

Background: Prior exposure to cardiotoxic cancer therapies has been associated with an increased risk of peripartum cardiomyopathy (PPCM). The management of PPCM in this population remains a clinical challenge. Few studies have explored the use of mechanical circulatory support in PPCM. We present a case of early implementation of intra-aortic balloon pump (IABP) therapy for acute stabilization and intrapartum support of PPCM. Case summary: A 36-year-old G4P2103 (4th pregnancy, two full-term, one premature birth, 0 abortions, and three living children) woman at 26 weeks and 5 days gestation with history of combined peripartum and anthracycline-induced cardiomyopathy [previously left ventricular ejection fraction (LVEF) 10-15% and recently 40-45%] presented with acute decompensated heart failure. Her clinical status deteriorated with a drop in LVEF to 15-20% with a significant increase in pulmonary pressures and worsening mitral regurgitation. A multidisciplinary decision with the cardio-obstetrics team was made to place a pulmonary artery catheter for invasive haemodynamic monitoring and IABP insertion prior to delivery. Intra-aortic balloon pump support had a profound immediate decrease in her systemic and pulmonary vascular resistance allowing for a successful repeat caesarean delivery. Her haemodynamics remained stable after IABP removal and pulmonary pressures improved. She was discharged one week following her delivery on guideline-directed medical therapy. Discussion: Our case highlights the use of prophylactic intrapartum IABP in combined anthracycline-induced and PPCM and begins to explore its safety and efficacy in this high-risk patient population.