Correlation of Non-Invasive Transthoracic Doppler Echocardiography with Invasive Doppler Wire-Derived Coronary Flow Reserve and Their Impact on Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention.

Background: Coronary microvascular dysfunction is associated with adverse prognosis after ST-segment elevation myocardial infarction (STEMI). We aimed to compare the invasive, Doppler wire-based coronary flow reserve (CFR) with the non-invasive transthoracic Doppler echocardiography (TTDE)-derived CFR, and their ability to predict infarct size. Methods: We included 36 patients with invasive Doppler wire assessment on days 3-7 after STEMI treated with primary percutaneous coronary intervention (PCI), of which TTDE-derived CFR was measured in 47 vessels (29 patients) within 6 h of the invasive Doppler. Infarct size was assessed by cardiac magnetic resonance at a median of 8 months. Results: The correlation between invasive and non-invasive CFR was modest in the overall cohort (rho 0.400, p = 0.005). It improved when only measurements in the LAD artery were considered (rho 0.554, p = 0.002), with no significant correlation in the RCA artery (rho -0.190, p = 0.435). Both invasive (AUC 0.888) and non-invasive (AUC 0.868) CFR, measured in the recanalized culprit artery, showed a good ability to predict infarct sizes ≥18% of the left ventricular mass, with the optimal cut off values of 1.85 and 1.80, respectively. Conclusions: In patients with STEMI, TTDE- and Doppler wire-derived CFR exhibit significant correlation, when measured in the LAD artery, and both have a similarly strong association with the final infarct size.

Acute Coronary Syndrome Following Transcatheter Aortic Valve Replacement.

Extending the indication of transcatheter aortic valve replacement (TAVR) to younger and lower-risk patients naturally results in longer life expectancy and survival rates after the intervention. The longer life expectancy of these patients leads to an increased possibility of future acute coronary events, necessitating the development of effective and appropriate treatment strategies. Acute coronary syndromes (ACS) in patients with previous TAVR procedures present with modified clinical characteristics when compared to the non-TAVR population. In populations with prior TAVR procedures, plaque rupture remains the main cause of ACS. However, unlike the non-TAVR population, there is an increased frequency of nonatherotrombotic mechanisms, like emboli and mechanical obstruction of coronary ostia by valve components. The main observation related to the treatment of ACS TAVR patients is the significantly lower percentage of patients undergoing invasive management. Furthermore, ACS in TAVR patients is associated with poor prognosis, higher long-term mortality rates, and higher incidence of MACE. It is surprising that considering this significant and increasingly recognized issue, there are only a few studies that have investigated ACS after TAVR. The scope of the present review is to address available data about ACS following TAVR, focusing on incidence, timing, mechanism, and causes. We also examined current knowledge regarding optimal invasive treatment and analyzed short and long-term clinical outcomes.

Coronary Microcirculation: The Next Frontier in the Management of STEMI.

Although the widespread adoption of timely invasive reperfusion strategies over the last two decades has significantly improved the prognosis of patients with ST-segment elevation myocardial infarction (STEMI), up to half of patients after angiographically successful primary percutaneous coronary intervention (PCI) still have signs of inadequate reperfusion at the level of coronary microcirculation. This phenomenon, termed coronary microvascular dysfunction (CMD), has been associated with impaired prognosis. The aim of the present review is to describe the collected evidence on the occurrence of CMD following primary PCI, means of assessment and its association with the infarct size and clinical outcomes. Therefore, the practical role of invasive assessment of CMD in the catheterization laboratory, at the end of primary PCI, is emphasized, with an overview of available technologies including thermodilution- and Doppler-based methods, as well as recently developing functional coronary angiography. In this regard, we review the conceptual background and the prognostic value of coronary flow reserve (CFR), index of microcirculatory resistance (IMR), hyperemic microvascular resistance (HMR), pressure at zero flow (PzF) and angiography-derived IMR. Finally, the so-far investigated therapeutic strategies targeting coronary microcirculation after STEMI are revisited.

Impact on long-term mortality of access and non-access site bleeding after primary percutaneous coronary intervention.

OBJECTIVES: The influence of the bleeding site on long-term survival after the primary percutaneous coronary intervention (PCI) is poorly understood. This study sought to investigate the relationship between in-hospital access site versus non-access site bleeding and very late mortality in unselected patients treated with primary PCI. METHODS: Data of the 2715 consecutive patients with ST-segment elevation myocardial infarction treated with primary PCI, enrolled in a prospective registry of a high volume tertiary centre, were analysed. Bleeding events were assessed according to the Bleeding Academic Research Consortium (BARC) criteria. The primary outcome was 4-year mortality. RESULTS: The BARC type ≥2 bleeding occurred in 171 patients (6.3%). Access site bleeding occurred in 3.8%, and non-access site bleeding in 2.5% of patients. Four-year mortality was significantly higher for patients with bleeding (BARC type ≥2) than in patients without bleeding (BARC type 0+1), (36.3% vs 16.2%, p<0.001). Patients with non-access site bleeding had higher 4 year mortality (50.7% vs 26.5%, p=0.001). After multivariable adjustment, BARC type ≥2 bleeding was the independent predictor of 4 year mortality (HR 2.01; 95% CI 1.49 to 2.71, p<0.001). Patients with a non-access site bleeding were at 2-fold higher risk of very late mortality than patients with an access site bleeding (HR 2.62; 1.78 to 3.86, p<0.001 vs HR 1.57; 1.03 to 2.38, p=0.034). CONCLUSIONS: Both access and non-access site BARC type ≥2 bleeding is independently associated with a high risk of 4-year mortality after primary PCI. Patients with non-access site bleeding were at higher risk of late mortality than patients with access site bleeding.

Improved Propensity-Score Matched Long-Term Clinical Outcomes in Patients with Successful Percutaneous Coronary Interventions of Coronary Chronic Total Occlusion.

The objective of the study was to evaluate major adverse cardiovascular events (MACE) after successful versus failed percutaneous coronary intervention for chronic total occlusion (PCI-CTO).Limited data are available on long-term clinical follow-up in the treatment of chronic total occlusion (CTO).Between January 2009 and December 2010 PCI-CTO was attempted in 283 consecutive patients with 289 CTO lesions. Procedural success was 62.3% and clinical follow-up covered 83% (235/283) of the study population with a median follow-up of 66 months (range, 59-74).The total incidence of MACE was 57/235 (24.3%), and was significantly higher in the procedural failure group than in the procedural success group (33/87 (37.9%) versus 24/148 (16.2%), P < 0.001). All-cause mortality was significantly lower in patients with successful PCI-CTO compared to failed PCI-CTO (10.8% versus 20.7%, P < 0.05). Also, the rate of cardiovascular death in the procedural failure group (14.9%) was slightly higher than that in the procedural success group (7.4%, P = 0.066). The rate of TVR was statistically higher in the procedural failure group (P < 0.009). Propensity score-adjusted Cox regression showed that procedural success remained a significant predictor of MACE (adjusted HR 0.402; 95% CI 0.196-0.824; P = 0.013).Our study emphasizes the importance of CTO recanalization in improving long-term outcome including all-cause mortality with a borderline effect on cardiovascular mortality.

Prognostic Value of Transthoracic Doppler Echocardiography Coronary Flow Velocity Reserve in Patients with Nonculprit Stenosis of Intermediate Severity Early after Primary Percutaneous Coronary Intervention.

BACKGROUND: Treatment of nonculprit coronary stenosis during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction may be beneficial, but the mode and timing of the intervention are still controversial. The aim of this study was to examine the significance and prognostic value of preserved coronary flow velocity reserve (CFVR) in patients with nonculprit intermediate stenosis early after primary percutaneous coronary intervention. METHODS: Two hundred thirty patients with remaining intermediate (50%-70%) stenosis of non-infarct-related arteries, in whom CFVR was performed within 7 days after primary percutaneous coronary intervention, were prospectively enrolled. Twenty patients with reduced CFVR and positive results on stress echocardiography or impaired fractional flow reserve underwent revascularization and were not included in further analysis. The final study population of 210 patients (mean age, 58 ± 10 years; 162 men) was divided into two groups on the basis of CFVR: group 1, CFVR > 2 (n = 174), and group 2, CFVR ≤ 2 (n = 36). Cardiac death, nonfatal myocardial infarction, and revascularization of the evaluated vessel were considered adverse events. RESULTS: Mean follow-up duration was 47 ± 16 months. Mean CFVR for the whole group was 2.36 ± 0.40. There were six adverse events (3.4%) related to the nonculprit coronary artery in group 1, including one cardiac death, one ST-segment elevation myocardial infarction, and four revascularizations. In group 2, there were 30 adverse events (83.3%, P < .001 vs group 1), including two cardiac deaths, two ST-segment elevation myocardial infarctions, and 26 revascularizations. CONCLUSIONS: In patients with CFVR > 2 of the intermediate nonculprit coronary lesion, deferral of revascularization is safe and associated with excellent long-term clinical outcomes.

Cesarean Section Rate Analysis in University Hospital Tuzla - According to Robson's Classification.

OBJECTIVE: For last decades, there has public concern about increasing Cesarean Section (CS) rates, and it is an issue of international public health concern. According to World Health Organisation (WHO) there is no justification to have more than 10-15% CS births. WHO proposes the Robson ten-group classification, as a global standard for assessing, monitoring and comparing cesarean section rates. The aim of this study was to investigate Cesarean section rate at University Hospital Tuzla, Bosnia and Herzegovina. METHODS: Cross sectional study was conducted for one-year period, 2015. Statistical analysis and graph-table presentation was performed using Excel 2010 and Microsoft Office programs. RESULTS: Out of 3,672 births, a total of 936 births were performed by CS. Percentage of the total number of CS to the total birth number was 25,47%. According to Robson classification, the largest was group 5 with relative contribution of 29,80%. On second and third place were group 1 and 2 with relative contribution of 26,06% and 15,78% respectively. Groups 1, 2, 5 made account of realtive contribution of 71,65%. All other groups had entirely relative contribution of 28,35%. CONCLUSION: Robson 10-group classification provides easy way in collecting information about CS rate. It is important that efforts to reduce the overall CS rate should focus on reducing the primary CS. Data from our study confirm this attitude.

A novel framework for fluid/structure interaction in rapid subject-specific simulations of blood flow in coronary artery bifurcations.

BACKGROUND/AIM: Practical difficulties, particularly long model development time, have limited the types and applicability of computational fluid dynamics simulations in numerical modeling of blood flow in serial manner. In these simulations, the most revealing flow parameters are the endothelial shear stress distribution and oscillatory shear index. The aim of this study was analyze their role in the diagnosis of the occurrence and prognosis of plaque development in coronary artery bifurcations. METHODS: We developed a novel modeling technique for rapid cardiovascular hemodynamic simulations taking into account interactions between fluid domain (blood) and solid domain (artery wall). Two numerical models that represent the observed subdomains of an arbitrary patient-specific coronary artery bifurcation were created using multi-slice computed tomography (MSCT) coronagraphy and ultrasound measurements of blood velocity. Coronary flow using an in-house finite element solver PAK-FS was solved. RESULTS: Overall behavior of coronary artery bifurcation during one cardiac cycle is described by: velocity, pressure, endothelial shear stress, oscillatory shear index, stress in arterial wall and nodal displacements. The places where (a) endothelial shear stress is less than 1.5, and (b) oscillatory shear index is very small (close or equal to 0) are prone to plaque genesis. CONCLUSION: Finite element simulation of fluid-structure interaction was used to investigate patient-specific flow dynamics and wall mechanics at coronary artery bifurcations. Simulation model revealed that lateral walls of the main branch and lateral walls distal to the carina are exposed to low endothelial shear stress which is a predilection site for development of atherosclerosis. This conclusion is confirmed by the low values of oscillatory shear index in those places.

Prognostic implications of bleeding measured by Bleeding Academic Research Consortium (BARC) categorisation in patients undergoing primary percutaneous coronary intervention.

OBJECTIVE: To investigate the relationship between inhospital bleeding as defined by Bleeding Academic Research Consortium (BARC) consensus classification and short-term and long-term mortality in unselected patients admitted for primary percutaneous coronary intervention (PCI). METHODS: We analysed data of all consecutive patients with ST segment elevation myocardial infarction (STEMI) admitted for primary PCI, enrolled in a prospective registry of a high volume centre. The BARC-defined bleeding events were reconstructed from the detailed, prospectively collected clinical data. The primary outcome was mortality at 1 year. RESULTS: Of the 1808 patients with STEMI admitted for primary PCI, 115 (6.4%) experienced a BARC type ≥2 bleeding. As the BARC bleeding severity worsened, there was a gradient of increasing rates of 1-year death. The 1-year mortality rate increased from 11.5% with BARC 0+1 type to 43.5% with BARC type 3b bleeding. After multivariable adjustment for demographic and clinical characteristics of patients, the independent predictors of 1-year death were BARC type 3a (HR 1.99; 95% CI 1.16 to 3.40, p=0.012) and BARC type 3b bleeding (HR 3.22; 95% CI 1.67 to 6.20, p<0.0001). CONCLUSIONS: The present study demonstrated that bleeding events defined according to the BARC classification hierarchically correlate with 1-year mortality after admission for primary PCI. The strongest predictor of 1-year mortality is the BARC type 3b bleeding.

Influence of blocks' topologies on endothelial shear stress observed in CFD analysis of artery bifurcation.

It is well known that endothelial shear stress affects occurrence of plaque in arteries. Lack of a method for measuring this physical quantity limits scientific understanding of this phenomenon. Application of numerical methods in this area has considerable amount of experimental verifications in terms of quantities that can be measured (velocity, pressure). On that basis we can rely on the results of endothelial shear stress calculations. The literature mainly documents the application of numerical methods to average geometries. However, arterial bifurcations are patient-specific. Moreover, occurrence of disease significantly complicates the geometry of the arteries and bifurcations. A multiblock concept provides the necessary geometrical flexibility and computational efficiency to generate patient-specific finite element models. For a particular class of problems different topologies of blocks are possible. This paper provides an overview of the possible block topologies required in finite element modeling using multiblock approach. In order to obtain accurate results of endothelial shear stress, two most general topologies are examined by numerical calculations. Favorable topology of the blocks is implemented in in-house software stl2fem.