Makoto Amaki

Standardized Imaging for Aortic Annular Sizing: Implications for Transcatheter Valve Selection

The safety and efficacy of transcatheter aortic valve replacement procedures are directly related to proper imaging. This report revisits the existing noninvasive and invasive approaches that have concurrently evolved to meet the demands for optimal selection and guidance of patients undergoing transcatheter aortic valve replacement. The authors summarize the published evidence and discuss the strengths and pitfalls of echocardiographic, computed tomographic, and calibrated aortic balloon valvuloplasty techniques in sizing the aortic valve annulus. Specific proposals for 3-dimensional tomographic reconstructions of complex 3-dimensional aortic root anatomy are provided for reducing intermodality variability in annular sizing. Finally, on the basis of the sizing approaches discussed in this review, the authors provide practical recommendations for balloon-expandable and self-expandable prostheses selection. Strategic use of echocardiographic, multislice computed tomographic, and angiographic data may provide complementary information for determining the anatomical suitability, efficacy, and safety of the procedure.

Extensive late gadolinium enhancement on cardiovascular magnetic resonance predicts adverse outcomes and lack of improvement in LV function after steroid therapy in cardiac sarcoidosis

Background Gadolinium-enhanced cardiovascular magnetic resonance is an emerging tool for the diagnosis of cardiac sarcoidosis (CS); however, the correlations between extent of late gadolinium enhancement (LGE) and efficacy of steroid therapy and adverse outcomes in patients with CS remain unclear. Objective We aimed to clarify the prognostic impact of extent of LGE in patients with CS. Methods Before the start of steroid therapy, 43 consecutive LGE-positive patients with CS were divided into two groups based on the extent of LGE by a median value: small-extent LGE (LGE mass <20% of LV mass; n=21) and large-extent LGE (LGE mass ≥20% of LV mass; n=22). We examined the correlations between extent of LGE and outcomes after steroid therapy. Results Among the 6 patients who died from heart disorders, 11 patients who were hospitalised because of heart failure and 6 patients who suffered life-threatening arrhythmia during the follow-up period, large-extent LGE predicted higher incidences of cardiac mortality and hospitalisation for heart failure. Multivariate Cox regression analysis showed that large-extent LGE was independently associated with combined adverse outcomes including cardiac death, hospitalisation for heart failure, and life-threatening arrhythmias. In the small-extent LGE group, LV end-diastolic volume index significantly decreased and LVEF significantly increased after steroid therapy, whereas in the large-extent LGE group, neither LV volume nor LVEF changed substantially. Conclusions Large-extent LGE correlates with absence of LV functional improvement and high incidence of adverse outcomes in patients with CS after steroid therapy.

Direct comparison of the diagnostic capability of cardiac magnetic resonance and endomyocardial biopsy in patients with heart failure

The diagnostic performance of cardiac magnetic resonance (CMR) has not been compared with that of other imaging modalities. Therefore, this study investigated the diagnostic capabilities of CMR and endomyocardial biopsy (EMB) in patients with heart failure (HF).

Impact of reduced left atrial functions on diagnosis of paroxysmal atrial fibrillation: Results from analysis of time-left atrial volume curve determined by two-dimensional speckle tracking

BACKGROUND Atrial fibrillation is commonly associated with impaired reservoir and booster functions of the left atrium (LA). Recent advances in two-dimensional speckle tracking technique (2DST) enabled automatic analysis of the time-LA volume curve representing these functions. Our objective was to evaluate LA function in patients with or without paroxysmal atrial fibrillation (PAF) using 2DST. METHODS We studied 111 patients (68 men, age 62 ± 16 years) with (n = 53) or without (n = 58) PAF. After constructing time-LA volume curves from the apical four and two chamber views (iE33, Philips with QLAB 6.0, Philips Medical Systems, Bothell, WA, USA), maximal LA volume (LAVmax), preatrial contraction LA volume (LAVpreA), and minimum LA volume (LAVmin) were obtained. Then, LA reservoir volume (ARV=LAVmax-LAVmin) and active emptying volume (AEV=LAVpreA-LAVmin) were calculated to determine ARV/LAVmax as reservoir function and AEV/LAVpreA as booster pump function. RESULTS PAF was associated with greater LAVmax than that in controls (80 ± 21 ml versus 65 ± 16 ml, p < 0.001) and with reduced reservoir and booster functions (ARV/LAVmax 46 ± 9% versus 52 ± 7%; AEV/LAVpreA 29 ± 10% versus 36 ± 6%, p < 0.001). Multivariate logistic analysis demonstrated that ARV/LAVmax and AEV/LAVpreA were closely associated with the existence of PAF. CONCLUSION These results demonstrate that the present 2DST enables determining LA reservoir and booster functions, providing insights into the diagnosis of PAF.

Plasma adiponectin levels predict cardiovascular events in the observational Arita Cohort Study in Japan: the importance of the plasma adiponectin levels.

As the plasma level of adiponectin is related to metabolic syndrome and cardiovascular events, a low plasma adiponectin level may either cause or trigger cardiovascular disorders. The purpose of this study was to determine whether a low adiponectin level contributes to cardiovascular events, and to investigate the factors influencing adiponectin in the Japanese Arita-cho cohort study.We followed about 2000 subjects in Arita-cho, Saga, Japan as a cohort study, and we enrolled 637 subjects (205 men; 65.1±8.3 years old) who participated in annual health checks from 2005 to 2008 and underwent measurement of the plasma adiponectin level and an oral glucose tolerance test. We monitored the incidence of cardiovascular or cerebrovascular events in these subjects until the end of 2010, discontinuing follow-up at 3 years after the start of enrollment. Subjects with low plasma adiponectin levels (<10.5 ng ml−1) had a higher incidence of newly diagnosed cardiovascular diseases such as acute heart failure or acute myocardial infarction than those with high plasma adiponectin levels (⩾10.5 ng ml−1) over an average of 2.95 years of follow-up. Multivariate analysis showed that the adiponectin level was predicted by the following parameters in all subjects: age (β=0.16), male gender (β=−0.267), homeostasis model assessment of insulin resistance (β=−0.140) and the plasma levels of high-density lipoprotein cholesterol (β=0.104), uric acid (β=−0.13), triglycerides (β=−0.169) and brain natriuretic peptide (β=0.151). The difference in plasma glucose before and 120 min after the intake of a 75-g glucose load did not influence the plasma adiponectin level. The plasma adiponectin level is useful for predicting cardiovascular events, and is a measure of the risk of lifestyle-related diseases.

Diagnostic Concordance of Echocardiography and CMR-Based Tissue Tracking for Differentiating Constrictive Pericarditis from Restrictive Cardiomyopathy

Background—Variations in longitudinal deformation of the left ventricle have been suggested to be useful for differentiating chronic constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM). We assessed left ventricular mechanics derived from cardiac magnetic resonance (CMR) cine–based and 2-dimensional echocardiography–based tissue tracking to determine intermodality consistency of diagnostic information for differentiating CP from RCM. Methods and Results—We retrospectively identified 92 patients who underwent both CMR and 2-dimensional echocardiography and who had a final diagnosis of CP (n=28), RCM (n=30), or no structural heart disease (n=34). Global longitudinal strain from long-axis views and circumferential strain from short-axis views were measured on 2-dimensional echocardiographic and CMR cine images using the same offline software. Logistic regression models with receiver operating characteristics curves, continuous net reclassification improvement, and the integrated discrimination improvement (IDI) were used for assessing the incremental predictive performance. Global longitudinal strain was higher in patients with CP than in those with RCM (P<0.001), and both techniques were found to have similar diagnostic value (area under the curve, 0.84 versus 0.88 for CMR and echocardiography, respectively). For echocardiography, the addition of global longitudinal strain to respiratory septal shift and early diastolic mitral annular velocity resulted in improved continuous net reclassification improvement (P<0.001 for both) and integrated discrimination improvement (P=0.005 and 0.024) for both models. Similarly, for CMR, the addition of global longitudinal strain to septal shift and pericardial thickness resulted in improved continuous net reclassification improvement (P<0.001 for both) and integrated discrimination improvement (P=0.003 and <0.001). Conclusions—CMR and echocardiography tissue tracking–derived left ventricular mechanics provide comparable diagnostic information for differentiating CP from RCM.

Usefulness of three-dimensional echocardiography in assessing right ventricular function in patients with primary pulmonary hypertension

Although right ventricular (RV) function is an important determinant of morbidity and mortality in patients with primary pulmonary hypertension (PPH), there have been no clinically validated quantification methods to date. The first derivative of RV pressure (dP/dt) is a good index of contractility, but it depends on preload. dP/dt divided by end-diastolic volume (EDV), that is, dP/dt/EDV, on the other hand, is an index of contractility relatively independent of preload. However, the measurement of accurate RV EDV is difficult because of RV complex geometry. Real-time three-dimensional (3D) echocardiography allows us to measure ventricular volume irrespective of its shape. To investigate the clinical feasibility and significance of 3D echocardiography in evaluating RV function in patients with PPH by measuring RV EDV and dP/dt/EDV, 13 patients with PPH (41±20 years, four men) underwent echocardiography, a 6-min walk distance (mWD) test and blood sampling within 1 week of invasive hemodynamic measurements. RV dP/dt was estimated from a continuous wave Doppler-determined tricuspid regurgitant velocity. RV EDV was measured by both two-dimensional (2D) biplane Simpson method (EDV2D) and real-time 3D echocardiography (EDV3D). RV dP/dt/EDV was calculated using EDV2D and EDV3D. EDV3D showed better correlations than EDV2D with the invasive and non-invasive parameters of RV function, suggesting the validity of volume measurement by 3D echocardiography. RV dP/dt/EDV3D correlated well with disease severity, whereas dP/dt and dP/dt/EDV2D did not. In patients with PPH, 3D-echocardiography-determined RV dP/dt/EDV and EDV seem to be potential markers of disease severity.

Exercise-Induced Changes of Functional Mitral Regurgitation in Asymptomatic or Mildly Symptomatic Patients With Idiopathic Dilated Cardiomyopathy

It has remained unclear why functional mitral regurgitation (MR), even if it is of a mild degree, has prognostic importance in patients with idiopathic dilated cardiomyopathy (IDC). Exercise-induced changes in functional MR, which might be a clue to this question, have not been fully clarified. Thus, in this study, semisupine exercise echocardiography was performed on 32 asymptomatic or mildly symptomatic patients with IDC (29 men, mean age 45 +/- 14 years). The mean ejection fraction was 28 +/- 10% (range 13% to 45%). The effective regurgitant orifice (ERO) area of MR was measured, as well as echocardiographic parameters including mitral valve geometry. ERO at rest was associated best with systolic mitral tenting area (r(S) = 0.85, p <0.001). Functional MR did not newly appear during exercise in 9 subjects without MR at rest. In the remaining 23 subjects with functional MR at rest, all showed exacerbations of MR, with a median ERO of 10.5 mm(2) (interquartile range 6.3 to 16.5) to 18.7 mm(2) (interquartile range 9.5 to 29.3) (p <0.001). An increase in ERO was correlated best with the enlargement of tenting area (r(S) = 0.90, p <0.001) and was the strongest independent determinant of exercise duration (beta = -0.55, p = 0.002, multiple R(2) = 0.46). In conclusion, functional MR complicated with IDC was significantly exacerbated during exercise, with mitral valve deformation, which was strongly related to exercise intolerance; thus, the clinical impact of functional MR in patients with IDC could be more serious than can be expected by its degree at rest.

Dynamic changes in plasma total and high molecular weight adiponectin levels in acute heart failure

BACKGROUND Elevated levels of total plasma adiponectin (APN) and high molecular weight (HMW)-APN have been observed in chronic heart failure (HF) and are associated with poor prognosis, however, the response of APN levels in acute HF is not known. The purpose of this study was to clarify the dynamic changes of the plasma total APN, HMW-APN levels, and the ratio of HMW-APN to total APN (HMWR) in acute HF. METHODS From February 2006 to January 2007, 20 patients with acute HF (non-ischemic and non-valvular origin, 17 men, aged 63±11 years) were enrolled, and blood was sampled before the onset of the treatment and at discharge. Ten patients admitted for the treatment of supraventricular arrhythmia (8 men, aged 45±13 years) were included as controls. RESULTS The medians and interquartile ranges of the plasma total APN, HMW-APN levels, and HMWR at admission were 20.8 (14.5-38.9) μg/mL, 12.4 (7.7-23.3) μg/mL, and 0.60 (0.50-0.69), respectively. The total APN and HMW-APN values were significantly higher than the values of the control. The plasma total APN, HMW-APN, and HMWR values at discharge decreased to 19.4 (7.2-27.3)μg/mL, 10.5 (3.2-12.8) μg/mL, and 0.52 (0.46-0.57), respectively. An exploratory survival analysis showed that the higher HMWR values at admission and the larger decrease in HMWR were associated with a better prognosis after discharge. CONCLUSION Plasma total APN and HMW-APN values are elevated at the admission for acute HF. Plasma total APN, HMW-APN, and HMWR values decrease following treatment. Higher HMWR at admission and its larger decrease may be the signs of favorable treatment responsiveness in acute HF.

Subclinical hypothyroidism is an independent predictor of adverse cardiovascular outcomes in patients with acute decompensated heart failure

Altered thyroid hormone metabolism characterized by a low triiodothyronine (T3), so‐called low‐T3 syndrome, is a common finding in patients with severe systemic diseases. Additionally, subclinical thyroid dysfunction, defined as abnormal thyroid stimulating hormone (TSH) and normal thyroxine (T4), causes left ventricular dysfunction. Our objective was to identify the prevalence and prognostic impact of low‐T3 syndrome and subclinical thyroid dysfunction in patients with acute decompensated heart failure (ADHF).