Comparison between the diagnostic performance of vessel fractional flow reserve and nonhyperemic pressure ratio for functionally significant coronary stenosis severity as assessed by fractional flow reserve.

BACKGROUND: Fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs) have been widely used to assess the functional severity of coronary stenosis. However, their measurement requires using a pressure wire, making their use in all patients difficult. The recently developed vessel fractional flow reserve (vFFR), derived from three-dimensional quantitative coronary angiography, is expected to serve as a surrogate for pressure wire assessment. METHODS: This retrospective study was conducted on patients with intermediate coronary stenosis who underwent FFR and NHPR measurements. The vFFR and NHPR values were compared for diagnosing coronary stenosis as defined by an FFR of ≤0.80, and the number of patients not requiring wire-based assessment was estimated. RESULTS: In a total of 90 lesions from 74 patients (median [SD] age 75 [12] years; men 80%), the median FFR was 0.78 (0.72-0.84), and 57% of these lesions (N = 51) exhibited an FFR of ≤0.80. vFFR provided high discrimination for coronary stenosis (area under the curve 0.80, 95% confidence interval 0.70-0.90), which was comparable to that of NHPRs (p = 0.42). High diagnostic accuracy was consistently observed across a variety of clinical presentations (i.e., old age, diabetes, target coronary artery, and left ventricular hypertrophy) (pinteraction > 0.05). In total, 55 lesions (61%) demonstrated positive or negative likelihood of coronary stenosis when vFFR was <0.73 (specificity 90%) or >0.87 (sensitivity 88%), respectively. CONCLUSION: vFFR demonstrated excellent diagnostic performance for detecting functionally significant coronary stenosis as evaluated by FFR. vFFR may be used as a surrogate for pressure wire assessment.

Potential of non-contrast stress T1 mapping for the assessment of myocardial injury in hypertrophic cardiomyopathy.

BACKGROUND: Ischemia of the hypertrophied myocardium due to microvascular dysfunction is related to a worse prognosis in hypertrophic cardiomyopathy (HCM). Stress and rest T1 mapping without contrast agents can be used to assess myocardial blood flow. Herein, we evaluated the potential of non-contrast stress T1 mapping in assessing myocardial injury in patients with HCM. METHODS: Forty-five consecutive subjects (31 HCM patients and 14 control subjects) underwent cardiac magnetic resonance (CMR) at 3T, including cine imaging, T1 mapping at rest and during adenosine triphosphate (ATP) stress, late gadolinium enhancement (LGE), and phase-contrast (PC) cine imaging of coronary sinus flow at rest and during stress to assess coronary flow reserve (CFR). PC cine imaging was performed on 25 subjects (17 patients with HCM and 8 control subjects). Native T1 values at rest and during stress were measured using the 16-segment model, and T1 reactivity was defined as the change in T1 values from rest to stress. RESULTS: ATP stress induced a significant increase in native T1 values in both the HCM and control groups (HCM: p < 0.001, control: p = 0.002). T1 reactivity in the HCM group was significantly lower than that in the control group (4.2 ± 0.3% vs. 5.6 ± 0.5%, p = 0.044). On univariate analysis, T1 reactivity correlated with native T1 values at rest, left ventricular mass index, and CFR. Multiple linear regression analysis demonstrated that only CFR was independently correlated with T1 reactivity (ß = 0.449; 95% confidence interval, 0.048-0.932; p = 0.032). Furthermore, segmental analysis showed decreased T1 reactivity in the hypertrophied myocardium and the non-hypertrophied myocardium with LGE in the HCM group. CONCLUSIONS: T1 reactivity was lower in the hypertrophied myocardium and LGE-positive myocardium compared to non-injured myocardium. Non-contrast stress T1 mapping is a promising CMR method for assessing myocardial injury in patients with HCM. Trial registration Retrospectively registered.

Association Between Endothelial Dysfunction and Left Ventricular Diastolic Stiffness　- Subanalysis of the Flow-Mediated Dilation Japan (FMD-J) Study.

BACKGROUND: Endothelial dysfunction and increased left ventricular (LV) stiffness are associated with the incidence of heart failure with preserved ejection fraction (HFpEF). This study evaluated the association between endothelial dysfunction and LV diastolic stiffness.Methods and Results: Endothelial dysfunction evaluated by flow-medicated vasodilation (FMD) and the reactive hyperemia index (RHI), which reflects endothelial dysfunction in the microvasculature, was measured in 112 subjects with hypertension in the Flow-Mediated Dilation Japan (FMD-J) study. Using transthoracic echocardiography, LV diastolic stiffness was evaluated by measuring diastolic wall strain (DWS) in the LV posterior wall. In this cross-sectional study, associations among FMD, RHI, and DWS were investigated using multiple regression analyses. The mean (±SD) age of the subjects 65±9 years, and 63% were men. DWS was significantly associated with RHI, but not FMD, on multivariate linear regression analysis (ß=0.39; P<0.0001). This association was preserved in subjects without LV hypertrophy (ß=0.46; P<0.0001). A DWS ≤median, suggesting increased LV diastolic stiffness, was significantly associated with RHI on multivariate logistic regression analysis (odds ratio 20.58; 95% confidence interval 4.83-87.63; P<0.0001). The receiver operating characteristic curve presented a cut-off value of 2.21 for RHI, with a sensitivity of 77% and a specificity of 71%, for DWS ≤median. CONCLUSIONS: RHI, rather than FMD, was associated with DWS. Endothelial dysfunction in the microvasculature may be associated with increased LV diastolic stiffness.

Comparison of the incidence of depression before and after endovascular treatment in patients with lower limb peripheral artery disease.

Depression is a chronic illness that affects mood, physical health, and overall vitality and quality of life. Depression has been associated with an increased risk of all-cause and cardiovascular mortality among patients with peripheral arterial disease (PAD). Therefore, this study aimed to compare the incidence of depression before and after endovascular treatment in patients with lower limb PAD. This is an important clinical issue considering the worldwide increase in PAD with the aging population and the known negative impact of depression on recovery. This was a retrospective sub-analysis of data from the Tokyo Peripheral Vascular Intervention Study using the TOMA-CODE registry. The presence and extent of depressive symptoms were evaluated using the patient health questionnaire (PHQ-9), with a depressive tendency score of ≥ 5. The PHQ-9 score was evaluated before endovascular treatment (EVT) and at 4 (± 1) weeks after EVT. The study population consisted of 87 patients who completed the PHQ-9 before EVT, with 76 completing the post-EVT PHQ-9. Of these 76, 19 had a pre-EVT score ≥ 5. Overall, there was no difference in the pre- and post-EVT scores (P = 0.091). There was no significant change in the 19 patients with a pre-EVT score ≥ 5 (mean 9.2 ± 4.4); however, there was a tendency to improve in the pre- to post-EVT score (mean, 6.9 ± 5.2; P = 0.059). Diabetes was a significant negative factor for pre- to post-EVT score improvement (P = 0.023). Overall, symptoms of depression showed the tendency to improve at 30 days post-EVT. However, diabetes was associated with lower improvement in symptoms.

Association Between Insulin Resistance, Oxidative Stress, Sympathetic Activity and Coronary Microvascular Function in Patients With Early Stage Impaired Glucose Metabolism.

BACKGROUND: Although acute hyperglycemia and insulin resistance (IR) are risk factors for atherosclerosis development through oxidative stress and sympathetic activation in diabetes mellitus, the association of these factors with coronary microvascular function in the early diabetic stage remains controversial.Methods and Results: Using transthoracic echocardiography, coronary flow velocity (CFV) and its reserve (CFVR) as parameters of coronary microvascular function were measured before and 1 h after an oral glucose tolerance test (OGTT) in 40 patients (aged 59±12 years) without diagnosed diabetes mellitus or coronary artery disease. Plasma glucose, insulin and thiobarbituric acid reactive substance (TBARS; an oxidative stress marker) were measured during the OGTT. IR was evaluated as homeostasis model assessment of IR (HOMA-R). Sympathetic activity was evaluated by using plasma catecholamines after OGTT. CFVR decreased after an OGTT (P<0.0001) mainly because of an increased baseline CFV (P<0.0001). Although the change in CFVR was not associated with the change in TBARS and catecholamines, it was independently associated with HOMA-R on the multivariate regression analysis (ß=-0.40, P=0.01). Another multivariate regression analysis revealed that change in baseline CFV was independently associated with HOMA-R (ß=0.35, P=0.03). CONCLUSIONS: IR, rather than oxidative stress and sympathetic activity, was associated with an increase in baseline CFV and a decline in CFVR during acute hyperglycemia. IR might play an important role in increased myocardial oxygen demand and coronary microvascular dysfunction.

Impact of sleep-disordered breathing on ventricular tachyarrhythmias after left ventricular assist device implantation.

Sleep-disordered breathing (SDB) is associated with an increased risk of adverse events in patients with heart failure (HF); however, its impact in patients implanted with a left ventricular assist device (LVAD) remains unclear. We aimed to investigate the prevalence of SDB in patients with LVAD and its impact on their clinical outcomes. Fifty consecutive patients with LVAD who underwent portable sleep monitoring between September 2017 and April 2018 were prospectively enrolled, and they were followed up for 170 ± 36 days. According to their respiratory disturbance indexes (RDIs), they were categorized into the SDB group (RDI ≥ 15, n = 12) and the non-SDB group (RDI < 15, n = 38). The incidence of adverse events during the follow-up period was investigated after enrollment. Multivariate logistic regression analysis revealed significant differences in SDB in LVAD-implanted patients in terms of the logarithmic transformation brain natriuretic peptide (BNP) values (p = 0.005). The optimal BNP cut-off value for SDB prediction in LVAD-implanted patients was 300 pg/mL (sensitivity: 58.3%, specificity: 94.7%). During follow-up, ventricular tachyarrhythmias (VTas) occurred significantly more frequently in the SDB group (4 [33%] vs. 2 [5%] patients, p = 0.02); Atrial tachyarrhythmia (ATa) also tended to occur more frequently in the SDB group (2 [25%] vs. 2 [2%] patients, p = 0.07). SBD was prevalent in 24% of the LVAD-implanted patients with advanced HF. Furthermore, SDB was significantly associated with high BNP levels and was also potentially associated with subsequent incidence of VTa in patients with LVAD.

[The case of an octogenarian who died of acute myocardial infarction complicated with acute pulmonary embolism from a right ventricular thrombus].

An 86-year-old female on dialysis experienced a decrease in blood pressure and worsening of her respiratory condition during dialysis, for which she visited our emergency unit. She was admitted to our Department of Cardiology with a diagnosis of acute myocardial infarction complicated with heart failure because of anterior wall of left ventricular dysfunction, positive troponin T levels and negative T wave on a precordial lead electrocardiogram. On the same day, she underwent coronary angiography and stenting at left anterior descending artery #7 with 99% stenosis. She also showed an elevated D-dimer level on admission, and contrast-enhanced computed tomography (CT) was performed the day after admission, considering the likelihood of respiratory failure due to pulmonary thromboembolism. However, the findings were negative. On the 4th day of hospitalization, she showed marked hypoxemia. Her D-dimer level was further elevated, and when she underwent enhanced CT again, there was no evidence of deep vein thrombosis, but thrombus in the pulmonary artery and apex of right ventricle was noted. She was therefore diagnosed with acute pulmonary embolism due to thrombosis from the right ventricle rather than from a deep vein. She rapidly received anticoagulant therapy and non-invasive positive pressure ventilation therapy for respiratory failure, but she entered cardiopulmonary arrest and quickly died. She was suspected to have been complicated with a right ventricular infarction and an acute anterior wall myocardial infarction, resulting in a large thrombus along the apex of the right ventricle. This case of both myocardial infarction and pulmonary embolism is very rare, and we report it here with consideration.

Clinical Differences of Recent Myocardial Infarction Compared With Acute Myocardial Infarction　- Insights From the Tokyo CCU Network Multicenter Registry.

BACKGROUND: Characteristics and treatment outcomes of acute myocardial infarction (AMI) patients have been studied; however, those of recent myocardial infarction (RMI) patients remain unclear. This study aimed to clarify characteristics, treatment strategy, and in-hospital outcomes of RMI patients in the Tokyo CCU network database.Methods and Results:In total, 1,853 RMI and 12,494 AMI patients from the Tokyo CCU network database during 2013-2016 were compared. Both RMI and AMI were redefined by onset times of 2-28 days and ≤24 h, respectively. The RMI group had a higher average age (70.4±12.9 vs. 68.0±13.4 years, P<0.001), more women (27.6% vs. 23.6%, P<0.001), lower proportion of patients with chest pain as the chief complaint (75.2% vs. 83.6%, P<0.001), higher prevalence of diabetes mellitus (35.9% vs. 31.0%, P<0.001), and higher mechanical complication incidence (3.0% vs. 1.5%, P<0.001) than did the AMI group. Thirty-day mortality was comparable (5.3% vs. 5.8%, P=0.360); major causes of death were cardiogenic shock and mechanical complications in the AMI and RMI groups, respectively. Death from mechanical complications (not onset time) in the AMI group plateaued almost 1 week after hospitalization, whereas it continued to increase in the RMI group. CONCLUSIONS: Both RMI and AMI patients have distinctive clinical features, sequelae, and causes of death. Although treatment of RMI patients adhered to guidelines, it was insufficient, and death from mechanical complications continues to increase.

Comparison of Mortality Prediction Models on Long-Term Mortality in Hospitalized Patients With Acute Heart Failure　- The Importance of Accounting for Nutritional Status.

BACKGROUND: The ideal mortality prediction model (MPM) for acute heart failure (AHF) patients would have sufficient and stable predictive ability for long-term as well as short-term mortality. However, published MPMs for AHF predominantly predict short-term mortality up to 90 days, and their prognostic performance for long-term mortality remains unclear. Methods and Results: We analyzed 609 AHF patients in a prospective registry from January 2013 to May 2016. We compared the prognostic performance for long-term mortality among 8 systematically identified MPMs for AHF that predict short-term mortality up to 90 days from admission. The PROTECT 7-day model showed the highest c-index for long-term as well as short-term mortality among the studied MPMs. Sensitivity analyses revealed serum albumin and total cholesterol to be the most important variables, as dropping these variables resulted in a significant decline in c-index, when compared with other variables specific to the PROTECT 7-day model. Furthermore, significant improvements in c-index and net reclassification were observed when serum albumin or serum albumin plus total cholesterol was added to the studied MPMs, other than the PROTECT 7-day model. CONCLUSIONS: The PROTECT 7-day model demonstrated the highest predictive performance for long-term as well as short-term mortality in AHF patients among the published MPMs. Our findings indicate the importance of accounting for nutritional status such as serum albumin and total cholesterol in AHF patients when developing a MPM.

Clinical and genetic backgrounds of hypertrophic cardiomyopathy with mid-ventricular obstruction.

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy. This study aimed to reveal the clinical and genetic backgrounds of the unique HCM with mid-ventricular obstruction (HCM-MVO) subtype. We identified 34 patients with HCM-MVO in our cohort, and about half (47%) of these patients experienced adverse events. We analyzed 67 cardiomyopathy-associated genes in the patients. In total, 44% of patients with HCM-MVO carried the cardiomyopathy-associated genetic variant (CAGV) in 14 genes. Only 21% of patients carried HCM-associated CAGVs in major sarcomere-encoding genes, while 18% of patients carried CAGVs in dilated cardiomyopathy/arrhythmogenic right ventricular cardiomyopathy-associated genes. CAGVs were more frequent in patients with asymmetric septal hypertrophy (ASH) than in those without ASH. These findings suggest that HCM-MVO is a high-risk group and may have different etiologies from typical HCM.

Cardiac sympathetic nervous system imaging with 123I-meta-iodobenzylguanidine: Perspectives from Japan and Europe.

Cardiac sympathetic nervous system dysfunction is closely associated with risk of serious cardiac events in patients with heart failure (HF), including HF progression, pump-failure death, and sudden cardiac death by lethal ventricular arrhythmia. For cardiac sympathetic nervous system imaging, 123I-meta-iodobenzylguanidine (123I-MIBG) was approved by the Japanese Ministry of Health, Labour and Welfare in 1992 and has therefore been widely used since in clinical settings. 123I-MIBG was also later approved by the Food and Drug Administration (FDA) in the United States of America (USA) and it was expected to achieve broad acceptance. In Europe, 123I-MIBG is currently used only for clinical research. This review article is based on a joint symposium of the Japanese Society of Nuclear Cardiology (JSNC) and the American Society of Nuclear Cardiology (ASNC), which was held in the annual meeting of JSNC in July 2016. JSNC members and a member of ASNC discussed the standardization of 123I-MIBG parameters, and clinical aspects of 123I-MIBG with a view to further promoting 123I-MIBG imaging in Asia, the USA, Europe, and the rest of the world.

Diagnostic Performance of a Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography System With Low-Dose Technetium-99m as Assessed by Fractional Flow Reserve.

BACKGROUND: Although stress single-photon emission computed tomography (SPECT) using a cadmium-zinc-telluride (CZT) camera facilitates radiation dose reduction, only a few studies have evaluated its diagnostic accuracy in Japanese patients by applying fractional flow reserve (FFR) measurements. METHODS AND RESULTS: We prospectively evaluated 102 consecutive patients with suspected or known coronary artery disease with a low-dose stress/rest protocol ((99m)Tc radiotracer 185/370 MBq) using CZT SPECT. Within 3 months, coronary angiography was performed and a significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or as a lesion of <90% and ≥ 50% stenosis with FFR ≤0.80. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 86%, 75%, and 82% for left anterior descending artery stenosis, 76%, 81%, and 79% for left circumflex artery stenosis, and 87%, 92%, and 90% for right coronary artery stenosis. When limited to 92 intermediate stenotic lesions in which FFR was measured, stress SPECT showed 77% sensitivity, 91% specificity, and 84% accuracy, whereas the diagnostic value decreased to 52% sensitivity, 68% specificity, and 58% accuracy based only on visual estimation of ≥75% diameter narrowing. CONCLUSIONS: CZT SPECT demonstrated a good diagnostic yield in detecting hemodynamically significant coronary stenoses as assessed by FFR, even when using a low-dose (99m)Tc protocol with an effective dose ≤5 mSv. (Circ J 2016; 80: 1217-1224).

Usefulness of phase analysis to differentiate ischemic and non-ischemic etiologies of left ventricular systolic dysfunction in patients with heart failure.

BACKGROUND: The detection of significant coronary artery disease (CAD) in patients with heart failure (HF) from left ventricular (LV) systolic dysfunction is crucial. We evaluated the usefulness of LV mechanical dyssynchrony as assessed by phase analysis compared with conventional gated single-photon emission computed tomography to identify ischemic etiology in patients with HF. METHODS AND RESULTS: Forty-one consecutive patients who were initially admitted to hospital due to HF resulting from systolic dysfunction were evaluated. All patients underwent cardiac catheterization. LV mechanical dyssynchrony was evaluated using SyncTool™ to obtain the phase SD and histogram bandwidth. The changes in phase SD and histogram bandwidth with stress were calculated. The summed stress score, summed difference score, and changes in phase SD and histogram bandwidth with stress were greater in 26 patients with CAD than in 15 patients without CAD (P=0.001 and P=0.01). On multivariate analysis a phase SD of >14° (odds ratio [OR], 16.7) and a summed stress score of >17 (OR, 8.0) best differentiated LV dysfunction of ischemic and non-ischemic etiologies, with a sensitivity of 89% and a specificity of 87% (χ(2)=20), compared with summed stress score only (sensitivity, 46%; specificity, 87%; χ(2)=4.5). CONCLUSIONS: The addition of phase analysis to conventional perfusion analysis enables better differentiation of the etiology of HF in patients with systolic dysfunction.

Diagnostic performance of a novel cadmium-zinc-telluride gamma camera system assessed using fractional flow reserve.

BACKGROUND: Although the novel cadmium-zinc-telluride (CZT) camera system provides excellent image quality, its diagnostic value using thallium-201 as assessed on coronary angiography (CAG) and fractional flow reserve (FFR) has not been validated. METHODS AND RESULTS: To evaluate the diagnostic accuracy of the CZT ultrafast camera system (Discovery NM 530c), 95 patients underwent stress thallium-201 single-photon emission computed tomography (SPECT) and then CAG within 3 months. Image acquisition was performed in the supine and prone positions after stress for 5 and 3 min, respectively, and in the supine position at rest for 10 min. Significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or a lesion with <90% and ≥50% stenosis and FFR ≤0.75. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 90%, 64%, and 78% for left anterior descending coronary artery stenosis, 78%, 84%, and 81% for left circumflex stenosis, and 83%, 47%, and 60% for right coronary artery (RCA) stenosis. The combination of prone and supine imaging had a higher specificity for RCA disease than supine imaging alone (65% vs. 47%), with an improvement in accuracy from 60% to 72%. CONCLUSIONS: Using thallium-201 with short acquisition time, combined with prone imaging, CZT SPECT had a high diagnostic yield in detecting significant coronary stenosis as assessed using FFR.

Central Systolic Blood Pressure as a Risk Factor for Accelerated Progression of Arterial Stiffness.

AIMS: In the arterial tree, a pressure gradient of the systolic blood pressure (SBP) is observed from the center to the periphery, with the pressure being higher in the periphery because of pressure wave reflection. However, this gradient is attenuated, with elevation of the central SBP (cSBP), in cases with abnormal pressure wave reflection in the arterial tree. It remains unclear if increase of the cSBP might be an independent risk factor for accelerated progression of arterial stiffness. We conducted this prospective observational study using latent growth curve model (LGCM) analyses to examine if elevated cSBP might be an independent risk factor for accelerated progression of the arterial stiffness in middle-aged Japanese men. METHODS: In this 9-year prospective observational study, we analyzed the data of 3862 middle-aged Japanese men (43±10years old) without cerebrocardiovascular disease at the study baseline who had undergone repeated annual measurements of the brachial-ankle pulse wave velocity (baPWV) and cSBP, as represented by the second peak of the radial pressure waveform (SBP2) in radial pressure waveform analysis. RESULTS: During the follow-up period (6.3±2.5years), significant increases of both the baPWV and SBP2 were observed in all the subjects. Analysis using the LGCM confirmed that the SBP2, a marker of the cSBP (B=0.260, P＜0.001), was a significant determinant of the slope of the annual changes of the baPWV during the study period. CONCLUSIONS: Our finding may appear to confirm elevated cSBP as an independent risk factor for accelerated progression of the arterial stiffness in middle-aged Japanese men.