Diagnostic performance of pressure-bounded coronary flow reserve.

Fluid dynamics studies have proposed that coronary flow reserve can be calculated from coronary artery pressure instead of coronary blood flow. We sought to investigate the diagnostic performance of pressure-bounded coronary flow reserve (pb-CFR) compared with CFR measured by conventional thermodilution method (CFRthermo) in the clinical setting. Pressure guidewire was used to measure CFRthermo and fractional flow reserve (FFR) in left anterior descending coronary artery in 62 patients with stable coronary artery disease. Pb-CFR was calculated only with resting distal coronary artery pressure (Pd), resting aortic pressure (Pa) and FFR. Pb-CFR was moderately correlated with CFRthermo (r = 0.54, P < 0.001). Pb-CFR showed a poor agreement with CFRthermo, presenting large values of mean difference and root mean square deviation (1.5 ± 1.4). Pb-CFR < 2.0 predicted CFRthermo < 2.0 with an accuracy of 79%, sensitivity of 83%, specificity of 78%, positive predictive value of 48%, negative predictive value of 95%. The discordance presenting CFRthermo < 2.0 and pb-CFR ≥ 2.0 was associated with diffuse disease (P < 0.001). The discordance presenting CFRthermo ≥ 2 and pb-CFR < 2 was associated with a high FFR (P = 0.002). Pb-CFR showed moderate correlation and poor agreement with CFRthermo. Pb-CFR might be reliable in excluding epicardial coronary artery disease and microcirculatory disorders.

A Novel Technique of Balloon Pulmonary Angioplasty for the Treatment of Total Occlusion Lesions.

Balloon pulmonary angioplasty (BPA) has been recognized as an alternative therapeutic approach for patients with inoperative chronic thromboembolic pulmonary hypertension and those with residual pulmonary hypertension after pulmonary endarterectomy. However, the safe and successful treatment rate for a total occlusion lesion (TOL) using BPA is low, mainly because vessels distal to the occlusion are invisible by angiogram. Here, we present the case of a 53-year-old woman with chronic thromboembolic pulmonary hypertension with successfully recanalization of a TOL by use of BPA with the aid of intracardiac echocardiography. The intracardiac echocardiography-assisted wire passage technique may be a promising method for safe and reliable TOL treatment using BPA.

Il est reconnu que l'angioplastie pulmonaire par ballonnet (APB) est une alternative thérapeutique chez les patients atteints d'hypertension pulmonaire thromboembolique chronique inopérable et chez les patients atteints d'hypertension pulmonaire résiduelle après l'endartériectomie pulmonaire. Toutefois, le taux d'innocuité et de réussite du traitement d'une occlusion totale (OT) à l'aide de l'APB est faible, principalement en raison de l'invisibilité des vaisseaux distaux de l'occlusion à l'angiographie. Dans cet article, nous présentons le cas d'une femme de 53 ans atteinte d'hypertension pulmonaire thromboembolique chez qui la recanalisation de l'OT par l'utilisation de l'APB à l'aide d'une échocardiographie intracardiaque a été réussie. La technique de passage du fil assistée par échocardiographie intracardiaque peut constituer une technique prometteuse pour traiter de façon sûre et fiable l'OT à l'aide de l'APB.

A Case of a Cardiac Resynchronization Therapy-Defibrillator Exhibiting a Lower and Alternately Variable Basic Rate.

A cardiac resynchronization therapy defibrillator (CRT-D) (Medtronic Inc. Protecta XT) was implanted in a 67-year-old man who had cardiac sarcoidosis with extremely low cardiac function. He had ventricular tachycardia which was controlled by catheter ablation, medication and pacing. The programmed mode was DDI, lower rate was 90 beats/minute, paced AV delay was 150 ms, and the noncompetitive atrial pacing (NCAP) function was programmed as 300 ms.After his admission for pneumonia and heart failure, we changed his DDI mode to a DDD mode because he had atrial tachycardia, which led to inadequate bi-ventricular pacing. After a while, there were cycle lengths which were longer than his device setting and alternately varied. We were able to avoid this phenomenon with AV delay of 120 ms and NCAP of 200 ms.NCAP is an algorithm which creates a gap above a certain period after the detection of an atrial signal during the postventricular atrial refractory period of the pacemaker. This is to prevent atrial tachycardia and repetitive non-reentrant ventriculoatrial (VA) synchrony in the presence of retrograde VA conduction. But in this case, NCAP algorithm induced much lower rate than the programmed basic lower rate. This situation produced some arrhythmias and exacerbated symptoms of heart failure. This had to be paid attention to, especially when the device was programmed at high basic heart rate.

Identification of the State of Maximal Hyperemia in the Assessment of Coronary Fractional Flow Reserve Using Non-Invasive Electrical Velocimetry.

Previous research revealed that, in patients with coronary pressure-derived fractional flow reserve (FFR) in the 'grey zone' (0.75-0.85), repeated FFR assessments sometimes yield conflicting results. One of the causes of the fluctuations in FFR values around the grey zone may be imprecise identification of the point where maximal hyperemia is achieved. Identification of the state of maximal hyperemia during assessment of FFR can be challenging. This study aimed to determine whether non-invasive electrical velocimetry (EV) can be used to identify the state of maximal hyperemia.Stroke volume (SV), SV variation (SVV), and systemic vascular resistance index (SVRI) were determined by EV in 15 patients who underwent FFR assessment. Time intervals from initiation of adenosine infusion to achieving maximal hyperemia (timemFRR), as well as to achieving maximal cardiac output (CO), SV, SVV, and SVRI (timemCO, timemSV, timemSVV, and timemSVRI, respectively), were determined. TimemCO and timemSVV were closer to timemFRR than other values (timemSVV/timemFRR versus timemSVRI/timemFRR = 1.03 ± 0.2 versus 1.36 ± 0.4, P < 0.05). The maximum of SV was difficult to determine owing to considerable variations, but the maximum of SVV was clearly recognized. TimemCO and timemSVV were significantly correlated with timemFFR, with timemSVV showing a stronger correlation than timemSV (timemSVV: r = 0.92, P < 0.01; timemCO: r = 0.80, P < 0.01).Maximal SVV is reached close to maximal hyperemia. Monitoring of SVV with non-invasive EV during FFR assessment can help identify the state of maximal hyperemia.

Correlation between driveline features and driveline infection in left ventricular assist device selection.

Although the survival rate for left ventricular assist device (LVAD) therapy has improved, device-related complications are an unpredictable threat to the patient's quality of life. We focused on driveline infection, and aimed to determine whether specific features of drivelines affect the frequency of infection. We enrolled patients who underwent LVAD implantation and were followed-up at our institute between 2007 and 2015. We counted the occurrences of driveline infection requiring any antibiotic therapy over a 2-year study period. Furthermore, we experimentally measured and compared the outer diameters and stiffness of three devices. Of all, 72 patients received an LVAD during the enrollment period. LVADs were HeartMate II (n = 32), EVAHEART (n = 22), and DuraHeart (n = 18). The outer diameters and stiffness were measured in five of each device. HeartMate II group had the highest driveline infection-free rate among all three devices during the study period (p = 0.042). The driveline of the HeartMate II LVAD had a significantly smaller outer diameter and lower stiffness than that of the other two devices (p < 0.05 for both). In conclusion, device-specific driveline features may affect the development of driveline infection during LVAD therapy.

Different Contributions of Physical Activity on Arterial Stiffness between Diabetics and Non-Diabetics.

BACKGROUND: We compared the contribution of physical activity to the change in arterial stiffness between patients with and without diabetes in ischemic heart disease. METHODS: We studied 96 (diabetes) and 109 (without diabetes) patients with ischemic heart disease treated by percutaneous coronary intervention (PCI). Arterial stiffness was assessed by cardio-ankle vascular index (CAVI) at the first diagnosis of significant coronary ischemia and 6 months after PCI and optimal medical therapy. Physical activity was evaluated using the long form of the International Physical Activity Questionnaire (IPAQ). RESULTS: CAVI values increased more for diabetic patients than for non-diabetic. The IPAQ scores did not differ between the two groups. During follow-up, CAVI values did not significantly change in either group. In diabetic patients, the CAVI score for 48 patients did not change (NC-group) and 48 patients improved (Improved-group). Physical activity scores were 937.9 ± 923.2 and 1524.6 ± 1166.2 in the NC- and Improved-groups, respectively. IPAQ scores and uric acid levels significantly affect CAVI improvement after adjusting for age, sex, baseline CAVI, total cholesterol, and estimated glomerular filtration rate. CONCLUSION: Determining factors influencing CAVI improvement during follow-up were significantly different between patients with and without diabetes. IPAQ scores and uric acid levels were significantly correlated with CAVI changes.

Brachial artery diameter has a predictive value in the improvement of flow-mediated dilation after aortic valve replacement for aortic stenosis.

Aortic stenosis (AS) is the most common valvular disease and aortic valve replacement (AVR) is one of its most effective interventions. AS affects not only the left ventricle, but also vascular function beyond the stenotic valve, which can lead to various types of vascular dysfunction. However, research evaluating the effect of AS on aortic vascular function is limited. In this study, we investigated clinical meaning to evaluate endothelial function in subjects with AS. From April 2011 to April 2012, 20 consecutive adult patients with degenerative AS (mean age, 74.7 ± 7.4 years; range 50-83 years) who underwent AVR at our institution were included in the study. We measured flow-mediated dilation (FMD) to evaluate the effect of AS on endothelial function. The difference between brachial artery diameter (BAD) before (4.0 ± 0.7 mm) and after AVR (3.9 ± 0.6 mm) was not significant (p = 0.043), but FMD significantly improved after AVR (from 3.1 ± 1.8 to 6.0 ± 2.7 %, p < 0.0001). We also analyzed FMD × BAD index, endogenous vasodilatory capability independent of BAD, resulting that it also significantly increased after AVR (12.3 ± 7.0-22.5 ± 9.3, p < 0.0001). We divided patients into two groups by pre- to post-AVR change in FMD (ΔFMD); large-ΔFMD group [ΔFMD >3.0 % (median value)] and small-ΔFMD group (ΔFMD <3.0 %). There were no significant changes in age, blood pressure, heart rate, B-type natriuretic peptide, or echocardiographic parameters in either group. In contrast, BAD was significantly larger in the small ΔFMD group (4.3 ± 0.7 mm) than in the large ΔFMD group (3.7 ± 0.7 mm) (p = 0.030). In addition, cardio-thoracic ratio was significantly greater in the small ΔFMD group (58.4 ± 7.1 %) than in the large ΔFMD group (53.7 ± 4.6 %) (p = 0.048). Receiver operating characteristic curve analysis of BAD to differentiate large and small ΔFMD demonstrated an area under the curve of 0.750 (p = 0.059) and that optimal cutoff for BAD was 4.28 mm (70 % sensitivity, 80 % specificity). AVR in subjects with AS is associated with a significant improvement in FMD in the brachial artery. Measurement of the BAD may be helpful in distinguishing whether the impairment of FMD in AS derives from a stenotic valve or vascular remodeling.

Cardiac allograft vasculopathy can be distinguished from donor-transmitted coronary atherosclerosis by optical coherence tomography imaging in a heart transplantation recipient: double layered intimal thickness.

Although survival after heart transplantation (HTx) has improved in recent years, cardiac allograft vasculopathy (CAV) is still the leading cause of remote morbidity and mortality in HTx recipients, partly because of difficulty with its diagnosis. In general, routine surveillance for CAV is advocated with coronary angiography accompanied by intravascular ultrasound (IVUS) if necessary. However, these modalities have limitations with respect to low spatial resolution, and sufficient qualitative/quantitative assessment of coronary intima has not been accomplished. Recently, optical coherence tomography (OCT) has emerged as a novel intracoronary imaging technique using an optical analogue of ultrasound with a spatial resolution of 10-20 µm, which is 10 times greater than IVUS. We here experienced a 49-year-old male who received a HTx 3 years ago, and OCT was executed during low molecular weight dextran injection. OCT demonstrated distinct double intimal layers probably consisting of a donor-transmitted atherosclerotic layer and an inner intimal proliferation due to CAV, which was indistinguishable by IVUS and virtual histological analyses. We believe that OCT imaging is not only a new loadstar during treatment of CAV but also a new generation modality for screening for early CAV in HTx recipients.