Challenging Case of Transcatheter Mitral Valve-in-Valve-in-Valve Replacement.

BACKGROUND A 39-year-old man with a complex valvular history of recurrent methicillin-resistant Staphylococcus aureus endocarditis with 2 surgical mitral valve replacements (in 2016 and 2017) followed by transcatheter mitral valve replacement (in 2019) presented with orthopnea, paroxysmal nocturnal dyspnea, chest pain, cough, and progressively worsening dyspnea on exertion. CASE REPORT Extensive workup was performed, including transesophageal echocardiogram, which revealed a malfunctioning, severely stenotic bioprosthetic valve. Left and right heart catheterization revealed mild non-obstructive coronary artery disease and severe pulmonary hypertension.

Delineation of epicardial stenosis in patients with microvascular disease using pressure drop coefficient: A pilot outcome study.

Aim: To investigate the patient-outcomes of newly developed pressure drop coefficient (CDP) in diagnosing epicardial stenosis (ES) in the presence of concomitant microvascular disease (MVD).

Methods: Patients from our clinical trial were divided into two subgroups with: (1) cut-off of coronary flow reserve (CFR) < 2.0; and (2) diabetes.

Evaluation of lesion flow coefficient for the detection of coronary artery disease in patient groups from two academic medical centers.

Background: In this study, lesion flow coefficient (LFC: ratio of % area stenosis [%AS] to the square root of the ratio of the pressure drop across the stenosis to the dynamic pressure in the throat region), that combines both the anatomical (%AS) and functional measurements (pressure and flow), was assessed for application in a clinical setting.

Methods And Results: Pressure, flow, and anatomical values were obtained from patients in 251 vessels from two different centers. Fractional flow reserve (FFR), Coronary flow reserve (CFR), hyperemic stenosis resistance index (HSR) and hyperemic microvascular index (HMR) were calculated.

Diagnostic cutoff for pressure drop coefficient in relation to fractional flow reserve and coronary flow reserve: A patient-level analysis.

Objectives And Background: Functional assessment of intermediate coronary stenosis during cardiac catheterization is conducted using diagnostic parameters like fractional flow reserve (FFR), coronary flow reserve (CFR), hyperemic stenosis resistance index (HSR), and hyperemic microvascular resistance (HMR). CDP (ratio of pressure drop across a stenosis to distal dynamic pressure), a nondimensional index derived from fundamental fluid dynamic principles, based on a combination of intracoronary pressure, and flow measurements may improve the functional assessment of coronary lesion severity.

Methods: Patient-level data pertaining to 350 intracoronary pressure and flow measurements across coronary stenoses was assessed to evaluate CFR, FFR, HSR, HMR, and CDP.

Benefit of ECG-gated rest and stress N-13 cardiac PET imaging for quantification of LVEF in ischemic patients.

Background: ECG-gated rest-stress cardiac PET can lead to simultaneous quantification of both left ventricular ejection fraction and flow impairment. In this study, our aim was to assess the benefit of rest and stress PET ejection fraction (EF) (EFp) in relation to single-photon emission computed tomography (SPECT) EF (EFs) and echocardiography EF (EFe). To this effect, the EFp was compared with EFs and EFe.

Lesion flow coefficient: a combined anatomical and functional parameter for detection of coronary artery disease--a clinical study.

Invasive diagnosis of coronary artery disease utilizes either anatomical or functional measurements. In this study, we tested a futuristic parameter, lesion flow coefficient (LFC, defined as the ratio of percent coronary area stenosis (%AS) to the square root of the ratio of the pressure drop across the stenosis to the dynamic pressure in the throat region), that combines both the anatomical (%AS) and functional measurements (pressure and flow) for application in a clinical setting. In 51 vessels, simultaneous pressure and flow readings were obtained using a 0.

Benefit of cardiac N-13 PET CFR for combined anatomical and functional diagnosis of ischemic coronary artery disease: a pilot study.

Background: Cardiac positron emission tomography (PET) can lead to flow impairment quantification using PET coronary flow reserve (CFRp: ratio of stress flow to rest flow) and is superior to the current standard, single-photon emission computed tomography. In this study, our first aim was to assess the benefit of CFRp in place of invasive CFR (CFRi) by comparing the correlations of each of the indices with combined pressure and flow index CDP, and combined functional (pressure-flow) and anatomical (%area stenosis, %AS) index, LFC. The second aim was to test the correlation between CFRp and CFRi.

Hyperemia-free delineation of epicardial and microvascular impairments using a basal index.

The assessment of functional coronary lesion severity using intracoronary hemodynamic parameters like the pressure-derived fractional flow reserve and the flow-derived coronary flow reserve are known to rely critically on the establishment of maximal hyperemia. We evaluated a hyperemia-free index, basal pressure drop coefficient (bCDP), that combines pressure and velocity for simultaneous assessment of the status of both epicardial and microvascular circulations. In 23 pigs, simultaneous measurements of distal coronary arterial pressure and flow were performed using a dual-sensor tipped guidewire in the settings of both normal and abnormal microcirculation with the presence of epicardial lesions of area stenosis (AS) < 50% and AS > 50%.

Diagnostic performance of pressure drop coefficient in relation to fractional flow reserve and coronary flow reserve.

Objectives And Background: Functional assessment of coronary lesion severity during cardiac catheterization is conducted using diagnostic parameters like fractional flow reserve (FFR; pressure derived) and coronary flow reserve (CFR; flow derived). However, the complex hemodynamics of stenosis might not be sufficiently explained by either pressure or flow alone, particularly in the case of intermediate stenosis. CDP (ratio of pressure drop across a stenosis to distal dynamic pressure), a non-dimensional index derived from fundamental fluid dynamic principles based on a combination of intracoronary pressure and flow, may improve the functional assessment of coronary lesion severity.

Impact of kissing balloon inflation on the main vessel stent volume, area, and symmetry after side-branch dilation in patients with coronary bifurcation lesions: a serial volumetric intravascular ultrasound study.

Objectives: Intravascular ultrasound (IVUS) was performed to investigate the impact of kissing balloon inflation (KBI) on the main vessel (MV) stent volume, area, and symmetry after side-branch (SB) dilation in patients with coronary bifurcation lesions (CBL).

Background: It remains controversial whether KBI would restore the MV stent area and symmetry loss after SB dilation.

Methods: A total of 88 serial IVUS examinations of the MV were performed after MV angioplasty, MV stenting, SB dilation, and KBI in 22 patients with CBL.

Functional diagnosis of coronary stenoses using pressure drop coefficient: a pilot study in humans.

Objectives And Background: Myocardial fractional flow reserve (FFR) in conjunction with coronary flow reserve (CFR) is used to evaluate the hemodynamic severity of coronary lesions. However, discordant results between FFR and CFR have been observed in intermediate coronary lesions. A functional parameter, pressure drop coefficient (CDP; ratio of pressure drop to distal dynamic pressure), was assessed using intracoronary pressure drop (dp) and average peak velocity (APV).

Effect of myocardial contractility on hemodynamic end points under concomitant microvascular disease in a porcine model.

In this study, coronary diagnostic parameters, pressure drop coefficient (CDP: ratio of trans-stenotic pressure drop to distal dynamic pressure), and lesion flow coefficient (LFC: ratio of % area stenosis (%AS) to the CDP at throat region), were evaluated to distinguish levels of %AS under varying contractility conditions, in the presence of microvascular disease (MVD). In 10 pigs, %AS and MVD were created using angioplasty balloons and 90-μm microspheres, respectively. Simultaneous measurements of pressure drop, left ventricular pressure (p), and velocity were obtained.

Congenital anastomosis between left anterior mammary and pulmonary vasculatures.

Several case reports have described the presence of acquired fistula connecting the left internal mammary artery to the pulmonary vasculature; however, occurrence of this type of congenital fistulas is less common. The authors present a case of a congenital left internal mammary artery-pulmonary vasculature fistula that was incidentally found during a coronary angiography in a patient who was being evaluated for coronary artery bypass surgery. The particulars of the case are discussed, and the literature is reviewed.

Effect of changes in contractility on pressure drop coefficient and fractional flow reserve in a porcine model.

Objectives And Background: Decisions based on invasive functional diagnostic measurements are often made in the setting of fluctuating hemodynamic variables that may alter resting or hyperemic measurements. The purpose of this investigation is to analyze the effect of myocardial contractility (CY) on invasive functional parameters. We hypothesize that the pressure drop coefficient (CDPe; ratio of pressure drop to distal dynamic pressure) and fractional flow reserve (FFR; ratio of average pressures distal and proximal to a stenosis) are not affected by fluctuations in CY and can distinguish between different severities of epicardial stenosis.

Safety and efficacy of drug eluting stents compared with bare metal stents for saphenous vein graft interventions: a comprehensive meta-analysis of randomized trials and observational studies comprising 7,994 patients.

Background: Saphenous vein graft (SVG) lesions remain amongst the most challenging lesions for percutaneous coronary intervention (PCI). It is unknown whether drug eluting stents (DES) are superior to bare metal stents (BMS) for such lesions. Our objective is to determine the safety and efficacy of DES compared with BMS for SVG lesions by performing a meta-analysis of clinical trials and observational studies.

Influence of heart rate on fractional flow reserve, pressure drop coefficient, and lesion flow coefficient for epicardial coronary stenosis in a porcine model.

A limitation in the use of invasive coronary diagnostic indexes is that fluctuations in hemodynamic factors such as heart rate (HR), blood pressure, and contractility may alter resting or hyperemic flow measurements and may introduce uncertainties in the interpretation of these indexes. In this study, we focused on the effect of fluctuations in HR and area stenosis (AS) on diagnostic indexes. We hypothesized that the pressure drop coefficient (CDP(e), ratio of transstenotic pressure drop and distal dynamic pressure), lesion flow coefficient (LFC, square root of ratio of limiting value CDP and CDP at site of stenosis) derived from fluid dynamics principles, and fractional flow reserve (FFR, ratio of average distal and proximal pressures) are independent of HR and can significantly differentiate between the severity of stenosis.

Fibrinolytic therapy for very late stent thrombosis--is it a viable option?

Stent thrombosis (ST) has a very high case fatality and morbidity rates. The risk of very late ST is significantly increased with drug-eluting stents (DES) compared to bare-metal stents for at least up to 4 years. Discontinuation of clopidogrel therapy is the single most important consistently identified risk factor.

Novel use of twin-pass catheter in successful recanalization of a chronic coronary total occlusion.

One of the most difficult challenges in interventional cardiology has been in finding the approach to treat chronic total occlusions (CTOs). Here we present a case of recanalization of an angulated, calcified CTO. The lesion presented difficulty due to the lack of guidewire support to facilitate crossing of the CTO.