Takuma Sawa

High-sensitivity cardiac troponin T in essential hypertension

BACKGROUND Myocyte injury might be involved in the progression of essential hypertension (EHT) toward heart failure (HF). However, in the absence of high-sensitivity (hs) assay, cardiac troponin T (TnT) in EHT has not been measurable. METHODS AND RESULTS We studied 236 consecutive ambulatory patients (mean age=65.5 years; 110 men) with treated EHT (mean systolic blood pressure=134.3 mmHg, mean serum N-terminal pro-B-type natriuretic peptide=86.6 pg/ml) for mean 65.6 months. Patients with a history of HF were excluded. Single and multiple variable analyses were performed in search of clinical correlates of elevated hs-TnT (≥0.003 ng/ml). Serum concentration of hs-TnT was ≥0.003 ng/ml (mean=0.008 ng/ml) in 184 patients. By single variable analysis, age, uric acid, log-transformed N-terminal pro-B-type natriuretic peptide, brachial-ankle pulse wave velocity, Cornell electrocardiographic (ECG) voltage, and number of antihypertensive medications were associated with log-transformed hs-TnT, while hemoglobin and estimated glomerular filtration rate (eGFR) were inversely correlated with log-transformed hs-TnT. By multivariate analysis, age, eGFR and Cornell voltage were independent correlates of log-transformed hs-TnT, even after adjustment for clinical backgrounds including known prognostic biomarkers of EHT. CONCLUSIONS hs-TnT was ≥0.003 ng/ml in 78% of patients presenting with treated EHT and independently correlated with age, renal function, and ECG voltage of hypertrophy.

Comprehensive Functional Assessment of Right-Sided Heart Using Speckle Tracking Strain for Patients with Pulmonary Hypertension.

Right ventricular (RV) systolic function is one of the most important determinants of outcome for pulmonary hypertension (PH) patients, but the factors influencing prognosis vary widely. Elevated right atrial (RA) pressure is reported to be one of these prognostic factors, but its functional importance has scarcely been assessed.

Association of Apical Longitudinal Rotation with Right Ventricular Performance in Patients with Pulmonary Hypertension: Insights into Overestimation of Tricuspid Annular Plane Systolic Excursion

Current guidelines recommend the routine use of tricuspid annular plane systolic excursion (TAPSE) as a simple method for estimating right ventricular (RV) function. However, when ventricular apical longitudinal rotation (apical‐LR) occurs in pulmonary hypertension (PH) patients, it may result in overestimated TAPSE.

Bi-ventricular contractile reserve offers an incremental prognostic value for patients with dilated cardiomyopathy

AIMS Right ventricular (RV) as well as left ventricular (LV) function has been recognized as an important prognostic factor for heart failure patients. Our objective was thus to investigate the prognostic significance of combined assessment of bi-ventricular functional reserve for patients with dilated cardiomyopathy (DCM). METHODS AND RESULTS We studied 104 DCM patients with ejection fractions (EF) of 32 ± 9%, and speckle-tracking echocardiography was used to assess both RV and LV contractile reserve under dobutamine stress (20 µg/kg/min). RV contractile function was measured as peak global longitudinal strain (GLS) from the RV free wall (RV-free), and LV function as global circumferential strain (GCS) and GLS, respectively. Event-free survival was then tracked for 17 months. Twenty-one patients (20%) developed cardiovascular events. A multivariate Cox proportional-hazards analysis revealed that the baseline EF, E/A, and the relative change in EF (ΔEF), in GCS (ΔGCS), and in RV-free (ΔRV-free) during dobutamine stress were the independent predictors of cardiovascular events (P < 0.001, <0.05, <0.01, <0.05, and <0.01, respectively). A Cox model based on baseline clinical and echocardiographic variables (χ(2) = 23.6) was improved by the addition of LV contractile reserve parameters (plus ΔGCS and ΔEF) (χ(2) = 49.1; P < 0.001) and further improved by adding RV contractile reserve (plus ΔRV-free) (χ(2) = 60.3, P < 0.001). CONCLUSION Assessment of RV contractile reserve during dobutamine stress offers a significantly better prognostic value for patients with DCM. Bi-ventricular contractile reserve may be required for a favourable outcome, so that estimation of RV contractile reserve should be considered part of a comprehensive functional assessment of these patients.

Impaired Mechanics of Left Ventriculo-Atrial Coupling in Patients With Diabetic Nephropathy

BACKGROUND Diabetic nephropathy is independently associated with longitudinal systolic dysfunction of the left ventricle (LV) in asymptomatic diabetes mellitus (DM) patients with preserved LV ejection fraction (LVEF). However, the effect of diabetic nephropathy on left atrial (LA) function remains unknown. METHODSANDRESULTS We studied 198 asymptomatic DM patients (LVEF ≥50%). Diabetic nephropathy was defined as a protein level higher than for micro-albuminuria. LV global longitudinal strain (GLS) and LA strain were analyzed by 2D speckle-tracking; 69 age-, sex-, and LVEF-matched controls were also studied. GLS and LA strain in systole (LAS-s) decreased significantly from normal controls to DM patients without (n=137) and with nephropathy (n=61), in that order. Furthermore, GLS, LAS-s, and LA strain in late diastole (LAS-a) were significantly lower in DM patients with macro-albuminuria (n=19) than in those with micro-albuminuria (n=42). Although 1 multivariate regression analysis identified albuminuria as an independent determinative factor of LAS-s among other relevant clinical background factors (β=-0.16, P=0.002), another multivariate regression model for LAS-s+GLS (β=0.40, P<0.001) showed that albuminuria was not a significant factor (β=-0.02, P=0.68). Similarly, another multivariate regression model including GLS (β=0.32, P<0.001) demonstrated that clinical features relevant for LAS-a, except for age, were not independent determinants of LAS-a. CONCLUSIONS The cross-linked association of LA strain with GLS and albuminuria may be important for better understanding the development of diabetic cardiomyopathy. (Circ J 2016; 80: 1957-1964).

Association of Left Atrial Booster‐Pump Function with Heart Failure Symptoms in Patients with Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction

Identification of heart failure (HF) symptoms in patients with severe aortic stenosis (AS) and preserved left ventricular (LV) ejection fraction (EF) is clinically important, but assessment of HF symptoms is challenging. It was recently reported that resting left atrium (LA) functions are related to exercise performance and are also important prognostic markers for patients with HF. The aim of this study was to assess the association of the HF symptoms with LA function in patients with severe AS and preserved LVEF.

Impact of left ventricular longitudinal functional mechanics on the progression of diastolic function in diabetes mellitus

Left ventricular (LV) diastolic dysfunction and longitudinal systolic dysfunction were identified in patients with diabetes mellitus (DM). This study’s aim was to investigate the impact of LV longitudinal systolic function on LV diastolic function in DM patients with preserved LV ejection fraction (LVEF). We studied 177 DM patients with preserved LVEF (all ≥50%), and 82 age-, gender- and LVEF-matched healthy volunteers as control. Global longitudinal strain (GLS) was defined as the average peak strain of 18 segments from standard apical views, GLS <18% as subclinical LV systolic dysfunction (LVSD), and LV dispersion as the standard deviation of time-to-peak strain from the same views. For DM patients with LVSD (n = 74), E/A and E’ were lower, and E/E’ and isovolumic relaxation time (IVRT) were greater than for DM patients without LVSD (n = 103) and normal controls (n = 82). Moreover, these parameters were lower for DM patients without LVSD than for normal controls. Multivariate analysis revealed that GLS was a strong determinative factor for E’ and E/E’ (β = 0.30, p < 0.001 and β = −0.25, p < 0.001, respectively), as was LV dispersion for E-wave deceleration time and IVRT (β = 0.21, p = 0.002 and β = 0.30, p < 0.001, respectively) independently of age. For normal subjects, however, only age was associated with all LV diastolic parameters. In conclusions, in contrast to age-related LV diastolic dysfunction in normal subjects, in DM patients with preserved LVEF, LV diastolic function was associated with LV longitudinal systolic function and LV dispersion independently of age. Our findings have obvious clinical implications for the management of DM patients.

Impact of Right Ventricular Geometry on Mitral Regurgitation After Transcatheter Closure of Atrial Septal Defect

Worsening of mitral regurgitation (MR) is sometimes observed after closure of an atrial septal defect (ASD). However, since the mechanism of this deterioration remains unclear, the aim of our study was to investigate the effect of left (LV) and right ventricular (RV) geometry on MR after transcatheter closure of ASD.We studied 27 patients with ASD who underwent transcatheter closure. Echocardiography was performed before and 6 ± 2 months after the procedure. In addition to conventional echocardiographic parameters, full volume data of the whole LV and RV heart was obtained with 3-dimensional echocardiography. MR was quantified by measuring the width of the vena contracta, and was graded as mild (< 3.0 mm), moderate (3.0 to 6.9 mm), or severe (≥ 7.0 mm).Ten patients (37%) were classified as having worsening MR and the remaining 17 (63%) as not having worsening MR. The two groups showed similar baseline characteristics, except for patients with worsening MR being more likely to be older (P = 0.009) and having a larger left-to-right shunt of pulmonary and systemic blood flow ratio (P = 0.02). It is noteworthy that the horizontal-to-vertical ratio of basal-RV at end-systole for patients with worsening MR was significantly smaller than that for patients without worsening MR (1.0 ± 0.2 versus 1.4 ± 0.2, P < 0.0001). Furthermore, multivariate analysis showed that the horizontal-to-vertical ratio of basal-RV at end-systole was the independent predictor of worsening MR during follow-up (P < 0.001).RV geometry may affect MR after closure of ASD. The pre-operative horizontal-to-vertical ratio of basal-RV is considered useful for predicting worsening of MR after closure of ASD.

Associations of Exercise Tolerance With Hemodynamic Parameters for Pulmonary Arterial Hypertension and for Chronic Thromboembolic Pulmonary Hypertension

Purpose: Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are the main subgroups of pulmonary hypertension (PH). Despite differences in their etiologies, both diseases are characterized by vascular remodeling, resulting in progressive right heart failure. Noninvasive periodic evaluation of exercise tolerance has become increasingly important. Cardiopulmonary exercise testing (CPET) and a 6-minute walk test (6MWT) are now both recommended for evaluating exercise tolerance, but there is insufficient knowledge about possible differences in the associations of exercise tolerance with right heart catheterization (RHC) data for patients with PAH and CTEPH. Methods: A retrospective study was performed with 57 patients with PH (24 with PAH and 33 with CTEPH) all of whom underwent echocardiography, CPET, 6MWT, and RHC. Results: For both patients with PAH and CTEPH, peak heart rate during CPET was significantly higher than that from 6MWT, whereas minimum peripheral oxygen saturation during CPET and 6MWT was similar. For patients with PAH, significant correlations were observed between peak O2 and cardiac index (CI) (r = 0.59; P = .002) and between E/ CO2 slopes and CI (r =−0.46, P = .02), as well as a nonsignificant correlation tendency for peak O2 and pulmonary vascular resistance (PVR) and for E/ CO2 and PVR (r =−0.39; P = .05; and r = 0.39; P = .06, respectively). For patients with CTEPH, however, a significant correlation was observed only between E/ CO2 slopes and CI (r =−0.38; P = .02). Conclusion: PH etiology should be considered when assessing exercise tolerance, whereas CPET can be effective in addition to hemodynamic assessment by means of RHC for periodic evaluation during followup.

Risk Stratification of Future Left Ventricular Dysfunction for Patients with Indications for Right Ventricular Pacing due to Bradycardia

Although right ventricular (RV) pacing is the only effective treatment for patients with symptomatic bradycardia, it creates left ventricular (LV) dyssynchrony, which can induce LV dysfunction and heart failure. The current criterion for consideration of cardiac resynchronization therapy (CRT) is LV ejection fraction (LVEF) ≤ 35%, but indication for CRT in patients required for RV pacing with LVEF > 35% remains unclear.We studied 40 patients, all LVEF ≥ 35%, who had undergone implantable cardioverter-defibrillator implantation with RV pacing < 5%. Echocardiography was performed at baseline and during RV pacing. LV dyssynchrony was defined as anteroseptal-to-posterior wall delay from the mid-LV short-axis view using two-dimensional speckle-tracking radial strain (significant: ≥ 130 ms). Patients were divided into two groups based on baseline LVEF: normal LVEF ( ≥ 50%; n = 20) and mildly reduced LVEF (35-50%; n = 20).LVEF and LV dyssynchrony in patients with mildly reduced LVEF deteriorated significantly during RV pacing compared to those in patients with normal LVEF. Moreover, changes in LV dyssynchrony during RV pacing significantly correlated with changes in LVEF (r = -0.44, P < 0.01). Multivariate logistic regression analysis showed that baseline LVEF was the only independent predictor and baseline LVEF < 48% predictive of significant LV dyssynchrony during RV pacing.The extent of RV pacing-induced LV dysfunction may be associated with baseline LV function. These adverse effects on patients with mildly reduced LVEF of 35-50% and indications for RV pacing due to bradycardia can thus be prevented by CRT.