Current status and future perspectives of fractional flow reserve derived from invasive coronary angiography.

Assessment of the functional significance of coronary artery stenosis using invasive measurement of fractional flow reserve (FFR) or non-hyperemic indices has been shown to be safe and effective in making clinical decisions on whether to perform percutaneous coronary intervention (PCI). Despite strong evidence from clinical trials, utilization of these techniques is still relatively low worldwide. This may be to some extent attributed to factors that are inherent to invasive measurements like prolongation of the procedure, side effects of drugs that induce hyperemia, additional steps that the operator should perform, the possibility to damage the vessel with the wire, and additional costs. During the last few years, there was a growing interest in the non-invasive assessment of coronary artery lesions, which may provide interventionalist with important physiological information regarding lesion severity and overcome some of the limitations. Several dedicated software solutions are available on the market that could provide an estimation of FFR using 3D reconstruction of the interrogated vessel derived from two separated angiographic projections taken during diagnostic coronary angiography. Furthermore, some of them use data about aortic pressure and frame count to more accurately calculate pressure drop (and FFR). The ideal non-invasive system should be integrated into the workflow of the cath lab and performed online (during the diagnostic procedure), thereby not prolonging procedural time significantly, and giving the operator additional information like vessel size, lesion length, and possible post-PCI FFR value. Following the development of these technologies, they were all evaluated in clinical trials where good correlation and agreement with invasive FFR (considered the gold standard) were demonstrated. Currently, only one trial (FAVOR III China) with clinical outcomes was completed and demonstrated that QFR-guided PCI may provide better results at 1-year follow-up as compared to the angiography-guided approach. We are awaiting the results of a few other trials with clinical outcomes that test the performance of these indices in guiding PCI against either FFR or angiography-based approach, in various clinical settings. Herein we will present an overview of the currently available data, a critical review of the major clinical trials, and further directions of development for the five most widely available non-invasive indices: QFR, vFFR, FFRangio, caFFR, and AccuFFRangio.

Novel Assessment Tool For Coronary Artery Disease Severity During Screening Mammography.

Breast arterial calcifications (BACs) are common findings on mammography which are associated with an increased risk of the coronary artery disease (CAD). Our aim in the current study was to design measurement instruments of CAD prediction, with or without BACs, and its discriminatory validity in the diagnosis of CAD (expressed by Syntax score) in women. This was observational, prospective study in the women cohort which underwent mammography and angiography. In this study we have demonstrated that the total 'The Breast Arterial Calcification and Coronary Artery Disease Scale' (BACCADS) was good additional diagnostic tool for detection of patients with severe CAD.

Prediction of coronary plaque location on arteries having myocardial bridge, using finite element models.

This study was performed to evaluate the influences of the myocardial bridges on the plaque initializations and progression in the coronary arteries. The wall structure is changed due to the plaque presence, which could be the reason for multiple heart malfunctions. Using simplified parametric finite element model (FE model) of the coronary artery having myocardial bridge and analyzing different mechanical parameters from blood circulation through the artery (wall shear stress, oscillatory shear index, residence time), we investigated the prediction of "the best" position for plaque progression. We chose six patients from the angiography records and used data from DICOM images to generate FE models with our software tools for FE preprocessing, solving and post-processing. We found a good correlation between real positions of the plaque and the ones that we predicted to develop at the proximal part of the myocardial bridges with wall shear stress, oscillatory shear index and residence time. This computer model could be additional predictive tool for everyday clinical examination of the patient with myocardial bridge.

[Therapeutic approach in patients undergoing percutaneous coronary interventions]. / Terapijski pristup kod pacijenata koji se podvrgavaju perkutanim koronarnim intervencijama.

While the performance of percutaneous coronary interventions remains the domain of interventional cardiologists, the management of these patients before, during, and after the procedure is in the domain of general cardiologists, internists and primary care physicians. Therefore, for optimal patient care it is crucial that all engaged physicians should understand the procedural risks, complications and optimal treatment strategy before, during and after the procedure. Before a percutanous coronary intervention, patients with known allergies to iodinated contrast dye should be pretreated with oral corticosteroids and H1-receptor blockers. Diabetic patients as well as patients with renal failure need special care. Hydration is crucial for patients with renal insufficiency in order to minimise the risk of contrast nephropathy. Metformin therapy should be discontinued before the procedure in patients with renal failure in order to avoid lactic acidosis, and it should be reinstituted after the procedure only when normal serum creatine level is confirmed. Double antiplatelet therapy (aspirin plus clopidogrel) should be initiated at least six hours before the procedure. While aspirin therapy after the procedure is life long, the duration of clopidogrel therapy depends on the type of implanted stent (in patients with bare stents implanted clopidogrel should be taken at least 3 - 4 weeks post procedural, and in patients with drug-eluting stents implanted clopidogrel should be taken at least 6 - 12 months after the procedure due to in-stent restenosis prevention). Patients who experience typical anginal pain in a period of one to eight month after percutaneous coronary revascularization are likely to have restenosis, and they should be reevaluated with stress echocardiography and/or repeated coronary angiography.