Konstantinos Kalogeras

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.

Predictive Factors of Vascular Complications after Transcatheter Aortic Valve Implantation in Patients Treated with a Default Percutaneous Strategy

BACKGROUND Percutaneous approach techniques with closure device after transcatheter aortic valve implantation (TAVI) have diminished vascular complications (VC). In this retrospective study, we will report incidence and angiographic factors predisposing to major VC in patients undergoing TAVI using Prostar® XL closure device as a default strategy. METHODS Consecutive patients, who underwent TAVI transfemorally using Prostar® XL, were evaluated for the incidence of VC according to VARC criteria. Using arterial angiography, the femoral-iliac arterial tortuosity was adjusted for large arterial diameters and expressed as the ratio total tortuosity/arterial diameter (TT/AD). Arterial calcification, the combination of angulation and atheromatosis at the puncture site and ideal puncture were evaluated too. In all patients, 30 days of follow-up was available. RESULTS Eighty-four patients (80.2 ± 5.86 years, 39 males [46.4%]), who were consecutively treated with the transfemoral approach, were evaluated. In patients with major VC (17/84 [20.23%]) comparing to those without, arterial calcification (11 [64.7%] vs. 8 [11.9%], P < 0.01) and the TT/AD (30.2 ± 11.25 vs. 22.06 ± 8.64, P < 0.01) were independent predictors. Ideal puncture was achieved more frequently among patients without VC comparing to those with major (94.1% vs. 70.6%, P = 0.01). Blood transfusions (1.48 ± 0.37 vs. 2.45 ± 0.59, P = 0.023) were more frequent among patients with major VC. Finally, minimum creatinin clearance after TAVI predicted all-cause 30-day mortality (P = 0.021). CONCLUSIONS Major VC after TAVI with the use of Prostar closure device can be predicted by arterial calcification at the puncture site and TT/AD ratio. Minimum creatinin clearance after TAVI predicted 30-day mortality.

Residual Platelet Reactivity After Clopidogrel Loading in Patients With ST-Elevation Myocardial Infarction Undergoing an Unexpectedly Delayed Primary Percutaneous Coronary Intervention

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.

Inferior epigastric artery as a landmark for transfemoral TAVI. Optimizing vascular access

This study sought to investigate whether the site of common femoral artery (CFA) cannulation in regard to the inferior epigastric artery (IEA) is associated with the incidence of vascular complications in patients undergoing transfemoral aortic valve implantation (TAVI).

Biomarkers as a guide of medical treatment in cardiovascular diseases.

There is increasing interest in utilizing novel markers of cardiovascular disease risk and consequently, there is a need to assess the value of their use. In this paper, we will review the role of biomarkers in acute coronary syndromes, heart failure and risk stratification for cardiovascular events as guide for treatment scribing. In particular, high sensitivity assays for troponin evaluation detect with greater precision patients with elevated troponin. Therefore, direct and appropriate management is succeeded in these patients with reduction of complications due to earlier treatment, as well. Regarding heart failure, randomized trials that have evaluated biomarker guided treatment approach have not succeeded in establishing specific results for natriuretic peptides (BNP, NT-proBNP) use in terms of therapy guidance. Apart from them, a variety of novel or already used biomarkers, have been tested by small trials for heart failure management, without however, managing to dominate in every day care. Finally, as far as risk stratification for cardiovascular events is concerned, hsCRP has proved to be a strong but doubted biomarker. Therefore, lifestyle and behavioral modification remain the cornerstone of primary prevention.

Successful percutaneous aortic valve implantation via a stenotic left subclavian artery access

Severe aortic valve stenosis may be tackled with percutaneous aortic valve replacement instead of surgical replacement. At present, two CE marked prosthetic valves are available. The CoreValve ReValving System is primarily designed to be introduced transfemorally, while implantation via subclavian arteries has been described in cases of unsuitable femoral access. However, this route has been used when subclavian artery is free of disease. In this case report we describe a successful CoreValve ReValving System implantation via a diseased and tortuous left subclavian artery after predilatation balloon angioplasty. The prosthesis was then advanced in the native aortic valve, deployed, and successfully implanted. Techniques and manipulations are provided.

Atrial Fibrillation During or After TAVI: Incidence, Implications and Therapeutical Considerations

INTRODUCTION Aortic stenosis is one of the most frequent valvulopathy of modern time necessitating interventional therapy when symptoms arise and stenosis becomes severe. First line treatment has traditionally been surgical aortic valve replacement (SAVR). However in the last decade transcatheter aortic valve implantation (TAVI) with bioprosthetic valves has proved to be a sound solution for high-risk for SAVR or inoperable patients. As expected implantation of the bioprosthetic device requires administration of antiplatelet regimen to the patients for a certain period. Atrial fibrillation (AF) may occur frequently during the peri-procedural period. In this background, the occurrence of AF after device implantation may be a challenging issue. METHODS We performed a literature search of PubMed and Embase database. Published articles reporting the incidence, clinical implications and description of antithrombotic regimen of New-onset atrial fibrillation (NOAF) in individuals undergoing TAVI were considered eligible. Incidence, Implications and Antithrombotic Regimen: The overall occurrence of NOAF is reported to be 1%-32% after TAVI. Left atrial enlargement and transapical approach constitute independent predictors for NOAF. Additionally it has been shown that patients with AF face an increased risk of death irrespective of the type of AF. Patients, with a history of AF, present greater rate of death than individuals with NOAF. NOAF is responsible for cerebrovascular events (CVE) occurring in the subacute phase (days 1-30) after the procedure. The risk of stroke/transient ischemic attack after TAVI is increased at least two fold by the presence of atrial fibrillation. Empirically, a dual antiplatelet strategy has been used for patients undergoing TAVR, including aspirin and a thienopyridine. In cases where patients are in need of oral anticoagulation after TAVI a combination of aspirin or thienopyridine with acenocoumarol has been the preferred regimen. DISCUSSION Despite the continuously crescent use of TAVI for patients with symptomatic severe aortic stenosis, there are still many aspects of this procedure to be clarified. A lack of data exists from the available clinical trials regarding the appropriate anticoagulation therapy for patients with greater risk for thromboembolic events. As a result, patients treatment remains at the discretion of the physician. CONCLUSION Limited data are available regarding the optimal therapeutic regimen in patients undergoing TAVI who need therapy for AF. Carefully designed clinical studies might further clarify the incidence and interrelation between atrial fibrillation and TAVI. The balance between the efficacy and risk of anticoagulation needs to be further clarified in patients undergoing TAVI.

Dual or Single Antiplatelet Therapy After Transcatheter Aortic Valve Implantation? A Systematic Review and Meta-Analysis

BACKGROUND Transcatheter aortic valve implantation (TAVI) has undeniably earned a prestigious post in the quiver of interventional cardiologists against symptomatic severe aortic stenosis. Cerebrovascular events are listed within the most frequent complications. METHODS We performed a systematic search of EMBASE, MEDLINE, and the Cochrane library from inception to March 2016 for the following search terms (transcatheter AND antiplatelet) OR (transcatheter AND antithrombotic) to retrieve studies of dual antiplatelet treatment (DAPT) and single antiplatelet treatment (SAPT) in patients after TAVI to study thrombotic, hemorrhagic and cardiovascular events at 30 days post procedure. From a total of 208 records 4 studies met inclusion criteria. RESULTS In the included studies, 286 patients were enrolled in the DAPT group and 354 patients in the SAPT group. There was no difference in all-cause mortality, cardiovascular mortality, stroke, and myocardial infraction 30 days post TAVI between DAPT and SAPT. However, patients in the DAPT group had a significantly increased incidence of lethal and major bleeding at 30 days of follow-up and the incidence of the combined end-point of stroke, spontaneous MI, all-cause mortality and major bleeding was significantly higher in the DAPT group in comparison to the SAPT group. CONCLUSION DAPT compared to SAPT in patients after TAVI increases incidence of hemorrhagic events with no benefits in terms of thrombotic events and cardiovascular mortality. However, these data must be interpreted cautiously and the choice of DAPT over SAPT must be based on an individual patient characteristic according to medical practice criteria.

Impact of balloon aortic valvuloplasty on transcatheter aortic valve implantation with self-expandable valve

BACKGROUND Balloon aortic valvuloplasty (BAV) has been used prior to valve implantation of a self-expandable valve as part of the transcatheter aortic valve implantation (TAVI) procedure. We aimed to evaluate the impact of BAV prior to TAVI. METHODS We retrospectively studied 203 consecutive patients who were treated either with (pre-BAV-TAVI group) or without BAV (D-TAVI group). Implantation depth (ID) was angiographically measured at non-coronary cusp (NCC) and left coronary cusp (LCC) at: the starting point (stage-1), before (stage-2), and after (stage-3) final bioprosthesis release. Paravalvular regurgitation (PVR) and 1-year clinical follow-up were recorded. RESULTS Overall, from stage-1 to stage-3, prosthesis migrated toward the left ventricle, in both cusps and groups. At NCC a forward migration was observed from stage-1 to stage-2 in both groups (p<0.001). In the pre-BAV-TAVI group only, at NCC, an upward migration decreased the ID from stage-2 to stage-3 (p=0.022). PVR ≥grade 2, immediately after expansion was more frequently observed in pre-BAV-TAVI group (41% vs 22%, respectively; p=0.024). However, PVR was similar at discharge. Clinical parameters were comparable between the two groups. CONCLUSIONS The use of BAV prior to TAVI may have an impact on device final position, but not on short- and long-term clinical outcome.

Percutaneous closure of a large ascending aorta pseudoaneurysm due to mediastinitis using an amplatzer occluder device.

A 63-year old man presented with chest pain. He had undergone coronary artery bypass graft surgery 15 years earlier and mitral valve repair due to severe regurgitation 6 months earlier with a simultaneous right internal mammary artery (RIMA) to left anterior descending artery graft. The early