Quantitative analysis of carotid plaque vasa vasorum by CEUS and correlation with histology after endarterectomy.

BACKGROUND: Intraplaque neovascularization and vasa vasorum (VV) proliferation contribute in the progression and rupture of atherosclerotic lesions. Contrast enhanced ultrasonography (CEUS) has been reported to attain data regarding intraplaque neovessels and VV. However, whether the detection of microbubbles by CEUS within atherosclerotic plaques truly represents microvessels is a point of concern. We aimed to evaluate stable and unstable carotid artery plaque (CAP) VV pattern by CEUS and its correlation with histology and immunochemistry. PATIENTS AND METHODS: Patients with CAP scheduled for plaque endarterectomy were enrolled. CAP was initially identified by conventional ultrasonography and subsequently CEUS (harmonic ultrasound imaging with simultaneous intravenous contrast agent injection) was performed. The recorded image loops were evaluated by a semi-automated method. Plaque specimens were excised and underwent histological and immunochemical (for CD34, Vascular Endothelial Growth Factor, CD68 and CD3 antibodies) analysis. RESULTS: Fourteen patients (67.6 ± 10.2 years, 10 males) with a 86.9 ± 11.5 % degree of carotid artery stenosis were evaluated. Histology showed that half of the plaques were unstable. Enhancement of plaque brightness on CEUS was significant for both stable and unstable plaque subgroups (p = 0.018 for both). Immunochemistry showed that microvessels, as assessed by CD34 antibody, were more dense in unstable vs. stable plaques (36.6 ± 17.4 vs. 13.0 ± 7.2 respectively, p = 0.002). However, correlation between plaque brigthness enhancement on CEUS and microvessel density was significant only for stable (r = 0.800, p = 0.031) plaques. CONCLUSIONS: The identification of brightness enhacement during CEUS in carotid atherosclerotic plaques may not always reflect the presence of VV.

Residual platelet reactivity after clopidogrel loading in patients with ST-elevation myocardial infarction undergoing an unexpectedly delayed primary percutaneous coronary intervention. - Impact on intracoronary thrombus burden and myocardial perfusion-.

BACKGROUND: Residual platelet reactivity (RPR) after clopidogrel loading, measured by the VerifyNow assay, has been shown to predict 12-month clinical events in patients with acute coronary syndromes. However, links between coronary angiographic findings and outcome in patients with ST-elevation myocardial infarction (STEMI), with RPR have not been reported. We investigated whether RPR is associated with the amount of intracoronary thrombus burden (TB) in patients with STEMI undergoing unexpectedly-delayed primary percutaneous coronary intervention (pPCI). Moreover, we evaluated whether RPR might influence coronary flow and myocardial perfusion immediately post-pPCI. METHODS AND RESULTS: The VerifyNow assay was used to determine RPR after clopidogrel loading, expressed in P2Y12-Reaction-Units (PRU). Intracoronary-TB was angiographically estimated and stratified as TB-Grade-A, -B and -C. Thrombolysis In Myocardial Infarction (TIMI) flow and Myocardial Blush (MB) were also estimated post-PCI. A total of 74 consecutive patients who presented with STEMI were enrolled in the study. Patients with greater TB presented significantly higher PRU-levels (174.1 ± 91.5, 196.23 ± 113.4 and 252.8 ± 107.8 for TB-Grade A, B and C, respectively; P=0.044). PRU-levels >251.5 were shown to predict Large-TB (LTB; TB-Grade-C) (sensitivity=57.9%; specificity=77.8%; P=0.014). Impaired TIMI-flow and MB after PCI were significantly associated with higher PRU-levels (P < 0.001). CONCLUSIONS: Among the studied patients, those with a higher RPR after clopidogrel loading presented larger intracoronary TB, worse post-PCI myocardial flow and perfusion.

TAVI in the case of preexisting mitral prosthesis: tips & tricks and literature review.

Very limited data exist on transcatheter aortic valve implantation (TAVI) in the setting of a preexisting mitral prosthesis regarding the technique, potential complications, and outcomes. Here, we report two cases of transfemoral TAVI with a self-expanding bioprosthesis (CoreValve; Medtronic, Inc) in patients who had previously undergone mitral valve replacement (one with an Omniscience and one with a St. Jude prosthesis). A brief literature review is also presented.

A Modified Technique to Safely Close the Arterial Puncture Site After TAVI.

BACKGROUND: We describe a vascular closure technique, convenient in practice, that permits effective femoral artery closure after CoreValve (Medtronic) implantation during transcatheter aortic valve implantation (TAVI). Vascular complications of transfemoral access implantation have been associated with significantly increased patient morbidity and mortality, as well as with increased hospitalization, among patients undergoing TAVI. TECHNIQUE: The crossover technique is performed while using the sheath dilatator in order to tightly grasp the crossover wire; a peripheral artery balloon is inserted in the iliac artery and inflated above the puncture site. The 18 Fr sheath is removed while hemostasis is achieved in that way. Minor vascular complications were observed in 10% (3 out of 30) of the patients treated with this vascular closure technique. No major vascular complications were observed. CONCLUSIONS: The described vascular closure maneuver is operator friendly, without demanding special skills and can be added to the therapeutic quiver for minimizing vascular complications after TAVI.

Effect of transcatheter aortic valve implantation on the ascending aorta's elasticity.

BACKGROUND: The elastic properties of the ascending aorta were studied before and 1 week after transcatheter aortic valve implantation (TAVI). Previous studies have shown that the distensibility of the ascending aorta was decreased in the early post-operative period after aortic valve replacement. Aortic stiffness is a major moderator of arterio-ventricular coupling and an independent predictor of cardiovascular risk and mortality. We evaluated the effect of TAVI on the elastic properties of the ascending aorta in the early post-operative period. METHODS: Aortic distensibility (AD) and Aortic Stiffness Index (ASI) were evaluated using echocardiographic techniques and brachial artery pressure obtained by sphygmomanometry 2-3 days before and 7-8 days after TAVI. RESULTS: A total of 30 patients (14 males) were studied with a mean age of 79.9 ± 4.7 years and aortic valve area before TAVI of 0.61 ± 0.16 cm(2). Mean arterial pressure decreased significantly after TAVI (from 89.6 ± 8.9 mmHg to 83.3 ± 10.9 mmHg, p = 0.004). AD did not change significantly after TAVI (pre: 1.89 ± 1.11 cm(2)/(dynes × 10(6)), post: 2.05 ± 1.50 cm(2)/(dynes × 10(6)); p = 0.813). ASI also remained unchanged (pre: 11.4 ± 6.5, post: 15.6 ± 14.9; p = 0.349). CONCLUSIONS: The elastic properties of the ascending aorta did not change significantly in the early post-procedural period after TAVI. This may in part be attributable to the less invasive procedure (compared to aortic valve replacement) which has no effect on vasa vasorum flow.