Lower on-treatment platelet reactivity during everolimus-eluting stent implantation contributes to the resolution of post-procedural intra-stent thrombus: serial OCT observation in the PRASFIT-Elective study

Intra-stent thrombus (IS-Th) formed immediately after percutaneous coronary intervention (PCI) is associated with subsequent adverse coronary events. However, the impact of on-treatment platelet reactivity on IS-Th is unknown. PRASFIT-Elective is a multicenter study of PCI patients receiving prasugrel (20/3.75 mg, loading/maintenance dose) or clopidogrel (300/75 mg), with aspirin (100 mg). Among the 742 study patients, 111 were pre-specified for the OCT sub-study. Of these, 82 underwent OCT immediately after PCI to assess IS-Th and at an 8-month follow-up to evaluate the fate of the IS-Th. Lesions were considered resolved when IS-Th were detected after PCI but not on the follow-up or persistent when IS-Th were observed on both scans. The P2Y12 Reactive Unit (PRU) value was determined at the initial PCI and 4 and 48 weeks post-PCI. In 76 patients (86 lesions), we detected 230 IS-Th initially, and 196 IS-Th (85.2%) were resolved at the 8-month OCT. At PCI, but not 4 or 48 weeks after, the resolved IS-Th group had a lower PRU than the persistent IS-Th group (199 ± 101 vs. 266 ± 102, p = 0.008). Multivariate logistic regression analyses revealed that lower PRU at PCI and less calcified lesions were independent predictive factors for the resolution of IS-Th. Local lesion-related factors and lower on-treatment platelet reactivity at the time of PCI may contribute to the resolution of IS-Th after EES implantation, potentially improving clinical outcome.

Effect of daily glucose fluctuation on coronary plaque vulnerability in patients pre-treated with lipid-lowering therapy: a prospective observational study

OBJECTIVES

This study sought to investigate the effect of daily glucose fluctuation on coronary plaque properties in patients with coronary artery disease (CAD) pre-treated with lipid-lowering therapy.

BACKGROUND

There is growing evidence that glucose fluctuation, as a residual risk apart from dyslipidemia, is an important factor contributing to the development of CAD.

METHODS

This prospective study enrolled 70 consecutive CAD patients who were referred for percutaneous coronary intervention and whose low-density lipoprotein cholesterol level was <120 mg/dl under statin treatment or <100 mg/dl without statins. Daily glucose fluctuation was analyzed by measuring the mean amplitude of glycemic excursion (MAGE). The plaque properties in the culprit and nonculprit lesions were assessed by virtual histology intravascular ultrasound, and the volume percentage of necrotic core within the plaque (%NC) and the presence of thin-cap fibroatheroma were evaluated.

RESULTS

In total, 165 lesions were evaluated in 70 patients (40 diabetic and 30 nondiabetic patients). %NC was well correlated with MAGE (r = 0.490, p <0.001). A linear mixed effect model showed that MAGE had the strongest effect on %NC (coefficient β = 0.080 ± 0.020 [standard error], p < 0.001). The generalized linear mixed effect model revealed that MAGE was the only independent predictor of the presence of thin-cap fibroatheroma (odds ratio: 1.037; 95% confidence interval: 1.010 to 1.065; p = 0.007).

CONCLUSIONS

Daily glucose fluctuation may have an effect on coronary plaque vulnerability in patients with CAD pre-treated with lipid-lowering therapy. Further investigations should address the rationale for the early detection and control of glucose fluctuation in the era of universal statin use for CAD patients.

Left ventricular outflow tract obstruction caused by massive mitral annular calcification in a patient with hypertensive heart disease

Mitral annular calcification (MAC) is frequently observed, but it rarely causes left ventricular outflow tract (LVOT) obstruction (LVOTO). An 83-year-old woman with hypertension, diabetes, and dyslipidemia was admitted to our hospital because of exertional dyspnea. She was diagnosed with hypertensive heart disease. Her symptoms were exacerbated by exertion, and she had no symptoms at rest. Transthoracic echocardiography showed massive posterior MAC, a sigmoid septum, and LVOTO, with a peak gradient of 15.4 mmHg at rest. Systolic anterior motion of the anterior mitral leaflet was not found. Moreover, the LVOT gradient in the stress condition was evaluated, and an increased LVOT gradient (47.3 mmHg) and chest discomfort was noted after 20 μg/kg/min of dobutamine was administered and the Valsalva maneuver was used. Hence, the patient was diagnosed with latent LVOTO. Interestingly, the distance between the septal wall, which was protruding into the left ventricular cavity, and the mitral valve coaptation, which was pushed up by the posterior MAC, had become closer, causing dynamic LVOTO. Since it is difficult to treat LVOTO with medication, ultimately, septal myectomy and mitral valve replacement were performed, which improved her symptoms. Evaluating the LVOT pressure gradient in stress condition is important in patients with MAC. .

Evaluation of platelet reactivity using P2Y12 reaction units in acute coronary syndrome with essential thrombocythemia: A case report

Essential thrombocythemia (ET) has been reported to cause acute coronary disease. However, the efficacy of anti-platelet therapy for ET is unclear since there are individual differences in the platelet function of ET patients. Here we report a case of a 62-year-old man with ET who was admitted to our hospital because of acute coronary syndrome. He underwent coronary angioplasty. Dual anti-platelet therapy with aspirin (81 mg/day) and clopidogrel (75 mg/day) was subsequently initiated. We evaluated platelet reactivity in P2Y12 reaction units, and subsequently determined anti-platelet drugs and corresponding doses. <Learning objective: Essential thrombocythemia (ET) is a myeloproliferative disorder that causes acute coronary disease. As there are individual differences in the platelet function of patients with ET, the efficacy of anti-platelet therapy for these patients varies. Evaluation of platelet reactivity using P2Y12 reaction units is useful in determining appropriate anti-platelet drugs and corresponding doses.>.

Optical coherence tomography and histopathology assessment after implantation of first- and second-generation drug-eluting stents in a porcine coronary model

BACKGROUND

This study directly compared optical coherence tomography (OCT) and histopathology for the assessment of vascular response to first- and second-generation drug-eluting stents. METHODS AND RESULTS: Sirolimus-, everolimus-, and biolimus-eluting stents (SES, EES, and BES, respectively) were randomly implanted into the coronary arteries of 12 porcine. OCT was conducted after implantation: at 1, 3, and 6 months; histopathology was assessed at 3 and 6 months. At 1-month OCT, EES had the highest neointimal area (NA) and lowest neointimal unevenness score (NUS). At 6 months, NA and NUS were equivalent among the stent types. ∆NA from 1 to 6 months was lowest for EES, and ∆NA correlated with the histopathological inflammation score at 6 months, which was highest for SES (P<0.001). The mean signal intensity (MSI) and the attenuation were different for the stent types at 3 months, and were associated with inflammation score. Moderate diagnostic efficiency for measuring MSI was found, with an optimal cut-off of 6.88 predicting a high (≥grade 3) inflammation score.

CONCLUSIONS

EES had the greatest uniformity and the least neointimal proliferation and were associated with less persistent inflammation. OCT provides accurate morphometric data; furthermore, quantitative measurement of the optical properties may help assess histological inflammation, which was more predominantly associated with SES than with EES and BES.

Two-year vessel healing after everolimus-eluting stent implantation: serial assessment by optical coherence tomography

BACKGROUND

Previous reports have suggested the importance of delayed arterial healing and the development of neoatherosclerosis as major contributors to stent thrombosis and delayed restenosis. The difference of in vivo assessment of long-term vessel healing between first-generation drug-eluting stents and current generation everolimus-eluting stents (EESs) is limited. The aim of this study was to evaluate long-term arterial healing in EES in comparison with the first generation sirolimus-eluting stents (SES).

METHODS

We evaluated 31 EES (23 patients) and 8 SES (7 patients) by serial optical coherence tomography at 12 months (mid-phase) and 24 months (late-phase) after stenting and evaluated the change in neointimal thickness (NIT), the percentages of uncovered struts, peri-strut low intensity area (PLIA; region around stent struts homogenously lower-intensity appearance than surrounding tissue), and thrombus.

RESULTS

Although the average NIT showed no significant changes from the mid- to the late-phase follow-up in both EES and SES groups, the change in NIT and minimum lumen area was significantly larger in SES than EES (5.2±29.4 vs. 37.2±48.9; p=0.02, -0.06±0.36 vs. -0.45±0.74; p=0.04, respectively). The incidence of uncovered struts and struts with PLIA of EES was lower than those of SES, at both phases. Stents with in-stent thrombus of EES tended to be lower than that of SES at both phase follow-ups.

CONCLUSION

Although both SES and EES showed progressive luminal narrowing from the mid- to the late-phase follow-up, the extent of delayed lumen narrowing and delayed neointimal proliferation was significantly less in the second generation EES than the first generation SES. EESs seem to offer sustained stability in efficacy, without sacrificing safety, up to 2 years after implantation.

Analysis by optical coherence tomography of long-term arterial healing after implantation of different types of stents

BACKGROUND

Although drug-eluting stents have significantly reduced the midterm incidence of target lesion revascularization (TLR), in vivo studies on long-term vessel healing of sirolimus-eluting stents (SESs) and paclitaxel-eluting stents (PESs) are limited. The aim of this study was to compare long-term arterial healing with SESs and PESs.

METHODS

We evaluated 27 SESs (23 patients) and 21 PESs (20 patients) by serial optical coherence tomography at 6 months (midphase) and ≥ 3 years (late phase) after stenting and evaluated the change of neointimal thickness (NIT), the percentages of uncovered and malapposed struts, peristrut low-intensity area (region around stent struts with a homogeneously lower intensity appearance than surrounding tissue), thrombus, and atherogenic neointima.

RESULTS

At follow-up, most SESs showed a progressive increase in the average NIT, whereas PESs showed variable changes. Between midphase and late phase, NIT increased significantly in SESs (midphase, 94.1 ± 49.3; late phase, 130.2 ± 78.7; P = 0.001) but decreased significantly in PESs (midphase, 167.4 ± 122.9; late phase, 136.0 ± 77.7; P = 0.04). The percentages of uncovered struts decreased significantly in SESs; conversely, variable changes were observed in PESs. Peristrut low-intensity area and thrombus formation decreased in SESs but remained largely unchanged in PESs. The prevalence of atherogenic neointima was greater in the late phase than in the midphase in both groups but was similar for both stents.

CONCLUSIONS

Long-term vessel healing was different for SESs and PESs. Progressive vessel healing was consistently observed in SESs, whereas a heterogeneous process of delayed vessel healing was noted for PESs.

Stabilizing effect of combined eicosapentaenoic acid and statin therapy on coronary thin-cap fibroatheroma

BACKGROUND

The addition of highly purified eicosapentaenoic acid (EPA) to statin therapy prevents cardiovascular events. However, the impact of this treatment on vulnerable plaques remains unclear. The aim of this study was to assess the impact of adding EPA to a standard statin therapy on vulnerable plaques by serial optical coherence tomography (OCT).

METHODS

Forty-nine non-culprit thin-cap fibroatheroma (TCFA) lesions in 30 patients with untreated dyslipidemia were included. Patients were randomly assigned to EPA (1800 mg/day) + statin (23 TCFA, 15 patients) or statin only (26 TCFA, 15 patients) treatment. The statin (rosuvastatin) dose was adjusted to achieve a target low-density lipoprotein (LDL) level of <70 mg/dL. Post-percutaneous intervention and 9-month follow-up OCT were performed to evaluate morphological changes of TCFAs. The EPA/arachidonic acid (EPA/AA) ratio and pentraxin-3 (PTX3) levels were also evaluated.

RESULTS

Despite similar follow-up LDL levels, the EPA + statin group had higher EPA/AA ratios and lower PTX3 levels than the statin group. OCT analysis showed that the EPA + statin group had a greater increase in fibrous-cap thickness, with a greater decrease in lipid arc and lipid length. Macrophage accumulation was less frequently detected in the EPA + statin group than in the statin group at follow-up. When the patients were categorized according to their follow-up PTX3 tertiles, fibrous-cap thickness showed significant increase, and the incidence of macrophages accumulation decreased with lower PTX3 levels.

CONCLUSION

The concomitant use of EPA and rosuvastatin may stabilize vulnerable plaques better than the statin alone, possibly by suppressing arterial inflammation.

Impact of hemodialysis on local vessel healing and thrombus formation after drug-eluting stent implantation

BACKGROUND

Although hemodialysis (HD) is a suggested risk factor for stent thrombosis, its contribution to local vessel healing after drug-eluting stent (DES) implantation is unclear.

METHODS

A total of 121 patients (152 lesions treated with DES) who underwent 8-month follow-up coronary angiography with optical coherence tomography (OCT) were enrolled, and the findings were compared between patients with and without HD. To match baseline differences, mid-term OCT findings of 42 propensity score-matched lesions (21 non-HD vs. 21 HD) were compared. Effects of HD on the efficacy of antiplatelet therapy were also evaluated by VerifyNow assay (Accumetrics, San Diego, CA, USA).

RESULTS

Patients with HD had a significantly higher rate of thrombus formation than those without (64% vs. 33%, p = 0.007), although the baseline parameters and lesion characteristics differed between the groups. Multivariate logistic regression analysis revealed that HD was associated with an increased risk of thrombus formation (odds ratio 5.991, 95% confidence interval: 1.972-18.199, p = 0.002). Even after propensity-matching for patient background and balancing of angiographic and OCT variables, the risk of thrombus formation remained significantly higher in HD patients. The P2Y12-reaction unit was significantly increased after HD (Pre HD: 211 ± 75 vs. Post HD: 262 ± 59, p = 0.01), but patients without HD showed no increase during the same elapsed time (221 ± 88 vs. 212 ± 96, p = 0.19).

CONCLUSIONS

HD is a potential risk factor for subclinical thrombus attachment after DES therapy. Systemic problems, such as residual platelet reactivity, associated with HD as well as local vessel features in HD patients might contribute to the increased incidence of thrombus attachment and subsequent onset of thrombotic event after DES implantation.

Potential benefit of final kissing balloon inflation after single stenting for the treatment of bifurcation lesions--insights from optical coherence tomography observations

BACKGROUND

Treatment of coronary bifurcation lesions using a single stenting strategy is preferable over that using a 2-stent technique. The benefit of final kissing inflation (FKI), however, has not been established.

METHODS AND RESULTS

Seventy-two patients (76 lesions) with true bifurcation lesions treated with a single drug-eluting stent with FKI (n=33 lesions) or without FKI (non-FKI, n=43 lesions) were enrolled in this study. Optical coherence tomography (OCT) was performed at 6-12 months after implantation. Based on the OCT findings, the percentage of jailing struts (number of jailing struts/total number of struts at the bifurcation lesion) was calculated. Percentage of uncovered struts and frequency of thrombus attachment were each evaluated at the proximal, bifurcation, and distal segments. Major adverse cardiac events (MACE) were also evaluated. The percentage of jailing struts was significantly lower in the FKI than in the non-FKI group (5.8±6.2% vs. 17.3±6.1%, P<0.01). Thrombus attachment was less frequent in the FKI group (24.2% vs. 46.5%, P=0.046), especially at side-branch orifices (3.0% vs. 27.9%, P<0.001). The percentage of uncovered struts was lower in the FKI than non-FKI group at the proximal, bifurcation, and distal segments. The incidence of MACE was not different in this small cohort.

CONCLUSIONS

FKI might reduce the frequency of subclinical thrombus possibly by reducing the number of jailing struts. 

Natural consequence of post-intervention stent malapposition, thrombus, tissue prolapse, and dissection assessed by optical coherence tomography at mid-term follow-up

Aims

We performed this study to clarify natural consequences of abnormal structures (stent malapposition, thrombus, tissue prolapse, and stent edge dissection) after percutaneous coronary intervention (PCI).

Methods and results

Thirty-five patients treated with 40 drug-eluting stents underwent serial optical coherence tomography (OCT) imaging immediately after PCI and at the 8-month follow-up. Among a total of 73 929 struts in every frame, 431 struts (26 stents) showed malapposition immediately after PCI. Among these, 49 remained malapposed at the follow-up examination. The mean distance between the strut and vessel wall (S–V distance) of persistent malapposed struts on post-stenting OCT images was significantly longer than that of resolved malapposed struts (342 ± 99 vs. 210 ± 49 μm; P <0.01). Based on receiver-operating characteristic curve analysis, an S–V distance ≤260 µm on post-stenting OCT images was the corresponding cut-off point for resolved malapposed struts (sensitivity: 89.3%, specificity: 83.7%, area under the curve = 0.884). Additionally, 108 newly appearing malapposed struts were observed on follow-up OCT, probably due to thrombus dissolution or plaque regression. Thrombus was observed in 15 stents post-PCI. Serial OCT analysis revealed persistent thrombus in 1 stent, resolved thrombus in 14 stents, and late-acquired thrombus in 8 stents. Tissue prolapse observed in 38 stents had disappeared at the follow-up. All eight stent edge dissections were repaired at the follow-up.

Conclusion

Most cases of stent malapposition with a short S–V distance, thrombus, tissue prolapse, or minor stent edge dissection improved during the follow-up. These OCT-detected minor abnormalities may not require additional treatment.

Impact of stent platform of paclitaxel-eluting stents: assessment of neointimal distribution on optical coherence tomography

BACKGROUND

The Taxus Express™ paclitaxel-eluting stent (Express-PES) and Taxus Liberté™ PES (Liberté-PES) have identical drugs, drug doses, and polymers, but different stent platforms. The Liberté-PES platform has thinner struts, specifically designed for more uniform drug elution.

METHODS AND RESULTS

Fifty-four patients who underwent 6-month follow-up optical coherence tomography (OCT) after Express-PES (n=27) or Liberté-PES (n=27) implantation were enrolled. Longitudinal and circumferential uniformity of neointimal distribution was evaluated in 3-D by computing mean neointimal thickness (NIT) within 360 equally spaced radial sectors for every 1-mm cross-section. After stenting, intravascular ultrasound showed that Liberté-PES had a significantly smaller maximum angle between adjacent struts, with a tendency toward a lower incidence of % length of the segment with maximum angle >90° than Express-PES. Liberté-PES had a significantly thinner mean NIT than the Express-PES with comparable frequency of uncovered struts. Longitudinal and circumferential absolute variation of NIT expressed by standard deviation of NIT from each sector was significantly smaller for Liberté-PES than for Express-PES. Liberté-PES had a tendency toward a decreased incidence of thrombus and peri-strut low-intensity areas (findings suggestive of delayed arterial healing), compared to Express-PES.

CONCLUSIONS

Stent design and thickness appeared to affect neointima suppression of PES. The stent platform of the Liberté-PES may offer greater and more homogeneous reduction of neointimal proliferation spatially across the full length of the PES.

Cardiovascular effects of various colloidal solutions during major abdominal surgery

We examined the effects of various colloidal solutions on cardiovascular and oxygen transport variables for 26 patients undergoing gastrectomy under general anesthesia. Fluosol-DA, whole blood, 3% Dextran-40 (Saviosol), and 6% hydroxyethyl starch (hetastarch, Hespan) affected the right side of heart, but only whole blood and Fluosol-DA significantly increased cardiac output and oxygen delivery (DO2). Fluosol-DA may prove useful for critical care of hemorrhagic shock during operation or resuscitation in the immediate postoperative period.

Changes of lung water and cardiovascular parameters during neurosurgical procedures associated with various types of infusion

With the Swan-Ganz catheter and double indicator technique cardiovascular parameters and lung water were measured in 16 neurosurgical procedures. Five hundred millilitres of whole blood, Manitol or Fluosol-DA, or 1000 ml of lactate-Ringer solution was infused within 30 min, and various parameters were estimated and analysed. Extravascular lung water did not change with either solutions. Fluosol-DA showed the most powerful pressure effects. With whole blood and Fluosol DA, cardiac output and oxygen availability increased. Marked hemodilution was observed with the infusion of either Manitol, Fluosol-DA or lactate-Ringer solution, but only Fluosol-DA insured adequate oxygen supply to tissues by increase in oxygen capacity in blood. Fluosol-DA proved to be one of the suitable colloidal solutions to improve the hemodynamics and hemodilution during operation.

The effect of Fluosol-DA on pulmonary vessels

The infusion of Fluosol-DA will increase the pulmonary artery pressure and the capillary wedge pressure as well as increase the cardiac output. The changes were more marked with the infusion of Fluosol-DA compared to whole blood, Hespander, or Saviosol. Calculated pulmonary vascular resistance decreased with Fluosol-DA infusion and lung water did not increase. We reconfirmed that during infusion of Fluosol-DA, PaO2 increased in many cases and the calculated shunt ratio decreased as a result.

Respiratory changes after major burn injury

In 32 major burn patients, routine respiratory measurements and blood gases analysis were performed. Striking differences were found between survivors and nonsurvivors in these variables. Marked increased in minute volume and respiratory rate were observed in nonsurvivors starting from the 6th day postburn, while PaCO2 increased with larger tidal and minute volumes. At the same time, PaO2 was lower than in survivors. In survivors, the closing volume, maximum mid-expiratory flow rate, and peak rate were lower than the predicted normal values. This may indicate that after major burn injury, ventilatory power decreased and some pathological changes occurred in small airways and alveoli without apparent pulmonary complications. Marked differences in the changes of respiratory rate and min volume between survivors and nonsurvivors may indicate the value of simple respiratory measurements for prediction of outcome in burn patients.