Csaba Jenei

Wall shear stress in the development of in-stent restenosis revisited. A critical review of clinical data on shear stress after intracoronary stent implantation.

The average wall shear stress (WSS) is in 1 Pa range in coronary arteries, while the stretching effect of an implanted coronary stent can generate up to 3 × 105 times higher circumferential stress in the vessel wall. It is widely accepted that WSS plays a critical role in the development of restenosis after coronary stent implantation, but relevant clinical endpoint studies are lack-ing. Fluid dynamics modeling suggests an association between WSS and intimal hyperplasia, however, such an association is not established when the compensating healing process becomes an overshoot phenomenon. This review summarizes available clinical results and concepts of potential clinical importance.

Circulating ACE2 activity correlates with cardiovascular disease development

It was shown recently that angiotensin-converting enzyme activity is limited by endogenous inhibition in vivo, highlighting the importance of angiotensin II (ACE2) elimination. The potential contribution of the ACE2 to cardiovascular disease progression was addressed. Serum ACE2 activities were measured in different clinical states (healthy, n=45; hypertensive, n=239; heart failure (HF) with reduced ejection fraction (HFrEF) n=141 and HF with preserved ejection fraction (HFpEF) n=47). ACE2 activity was significantly higher in hypertensive patients (24.8±0.8 U/ml) than that in healthy volunteers (16.2±0.8 U/ml, p=0.01). ACE2 activity further increased in HFrEF patients (43.9±2.1 U/ml, p=0.001) but not in HFpEF patients (24.6±1.9 U/ml) when compared with hypertensive patients. Serum ACE2 activity negatively correlated with left ventricular systolic function in HFrEF, but not in hypertensive, HFpEF or healthy populations. Serum ACE2 activity had a fair diagnostic value to differentiate HFpEF from HFrEF patients in this study. Serum ACE2 activity correlates with cardiovascular disease development: it increases when hypertension develops and further increases when the cardiovascular disease further progresses to systolic dysfunction, suggesting that ACE2 metabolism plays a role in these processes. In contrast, serum ACE2 activity does not change when hypertension progresses to HFpEF, suggesting a different pathomechanism for HFpEF, and proposing a biomarker-based identification of these HF forms.

Nehéz helyzetben a HEART Team: valve-in-valve implantáció?

Napjainkban a transzkatéteres aortabillentyű-beültetés (TAVI) alternatív megoldásként szerepel a magas műtéti rizikójú, aortabillentyű-betegséggel rendelkező betegek kezelésében. 2003-ban szignifikáns aortabillentyű-szűkület miatt 25 mm-es Stentless Pericarbon Freedom biológiai műbillentyű-beültetésen átesett 79 éves nőbeteg felvételét (2017. május 17.) megelőzően két héttel jelentkező visszatérő láz, valamint echokardiográfiával igazolódott újkeletű súlyos aortabillentyű-elégtelenség miatt irányították Klinikánkra. Hagyományos TEE során felmerült mobilis vegetáció lehetősége, azonban szívsebészeti konzíliumot követően elvégzett 3D TEE-vizsgálat a non-koronáriás tasak kifejezett mobilitását és súlyos aortabillentyű-elégtelenséget igazolt (vena contracta area: 1,2 cm2), egyértelmű vegetáció nélkül. A látott szívultrahangos kép alapján a HEART Team a billentyűtasak ruptúráját valószínűsítette és tekintettel a beteg magas műtéti rizikójára két hét antibiotikum-kezelést követően valve-in-valve transzkatéteres műbillentyű-implantációt javasolt, amely Klinikánkon sikeresen megtörtént. Hazabocsájtását megelőzően elvégzett kontroll transztorakális szívultrahangon jól működő billentyű igazolódott.

Optical coherence tomography imaging of intrastent neointimal bridge caused by semicircumferencial dissection after drug eluting balloon dilatation of instent restenosis of sapheneous venous graft.

During redilatation of a stent by a balloon, the dissection of the neointimal tissue commonly can be detected by IVUS or OCT, but the exact clinical relevance of the dissection in variable type is not known in the case of angiographically good result. Sixty-two year old female patient had CABG operation in 1998 (LIMA-LAD, sequential SVG to the 2nd OM branch of the LCx and the PL of the RCA). Between 2006 and 2012 she had 5 PCIs with stent implantations and balloon redilations in the sequential SVG (altogether 5 BM stents and 1 DES were implanted). The last intervention before the index procedure was performed under IVUS guidance 7 months ago with paclitaxel eluting balloon (DEB) (Pantera Lux, Biotronik) redilatation because of recurrent restenosis. IVUS images showed dissection of the intrastent tissue immediately after redilatation (Fig. 1A, Video 1. See corresponding video/movie images at www. anakarder.com). The index procedure was indicated because of recurrent angina like symptoms. This case the coronary angiography showed only mild lumen narrowing inside the stents (Fig. 1B). OCT investigation detected a “bridge like” neointimal tissue in the previously dilatated stent (Fig. 1C, Video 2. See corresponding video/movie images at www.anakarder. com). Careful analysis of the OCT images revealed that the intrastent tissue bridge not detected even by IVUS during the previous intervention, originated from circumferencial intrastent dissection caused by the before DEB redilatation. This case shows that the redilatation of instent restenosis of the SVG by DEB can be associated such a stable form of circumferencial dissection of intrastent proliferation which does not limit the flow, furthermore functionally can serve as a “flow divider”. The long term prognosis of this phenomenon is unknown. Zsolt Köszegi, Tibor Szük, Gusztáv Vajda, Frederick Marty1, Csaba Jenei Institute of Cardiology, University of Debrecen, Debrecen-Hungary 1St. Jude Medical Export GmbH; Vienna-Austria

Relationship between reversibility score on corresponding left ventricular segments and fractional flow reserve in coronary artery disease.

Objective: The objective of this study was to find the correlation between the severity of perfusion abnormality detected by scintigraphy and the FFR value, as well as the localization of a particular coronary lesion. On the basis of FFR values and the corresponding left ventricular segments, we proposed a combined index to aim for better correlation with myocardial ischemia than the FFR parameter alone. Methods: Twenty-eight patients (male: 22, female: 6, age 62±7.62) having FFR measurements and myocardial perfusion SPECT studies were enrolled in our retrospective analysis. FFR measurements on 36 vessels (20 LAD, 6 LCx, 10 RCA) with intermediate stenosis (40%-60%) were compared to the Tc-99m SestaMIBI myocardial perfusion SPECT studies. SPECT studies were performed before the invasive procedure in all cases. We introduced a new ischemic index, the left ventricular ischemic index (LVIi), by combining FFR values with the number of corresponding myocardial segments (N) [LVIi=N x (1-FFR)]. This index correlated with the regional myocardial perfusion defects identified on the scintigrams. A perfusion reversibility score of 2 or above was considered indicative of active ischemia (regional difference score: rDSc). For the statistical analysis, we used linear regression analysis and receiver operating characteristic (ROC) curve analysis to compare the different parameters. Results: A close linear relationship was found between the LVIi and rDSc values (p<0.001) with linear regression analysis. When analyzing all FFR values independently of the localization of the lesions, they also correlated significantly to the rDSc, but this relation was not as close. LVIi predicted active ischemia (≥2 rDSc) on myocardial scintigraphy with 78% sensitivity and 94% specificity when the cutoff value was set to 0.96. FFR alone predicted ischemia on scintigraphy with 72% sensitivity and 94% specificity at the best 0.8 cut-off value. The area under the ROC curve was significantly higher for LVIi than FFR (0.94 vs. 0.87; p<0.05). Conclusion: The scintigraphic data indicate that an LVIi >0.96 implies a clinically relevant stenotic lesion. In our opinion, FFR values, weighted with the corresponding left ventricular segments, should be taken into consideration for the best clinical decision-making.