Seitetsu L. Lee

Evaluation of Right Ventricle by Speckle Tracking and Conventional Echocardiography in Rats With Right Ventricular Heart Failure

Speckle tracking echocardiography (STE) has been reported to be a promising technique for evaluating right ventricular (RV) function in the clinical setting. On the other hand, the usefulness of STE for RV evaluation in small animal models has not been clarified, although the rat model is among the most commonly used animal models to develop novel effective treatments against pulmonary hypertension and RV heart failure (HF).We validated the use of STE and conventional echocardiographic variables for evaluating RV functions in a rat model by comparing the echocardiographic values of RVHF rats (n = 12) induced by monocrotaline injection with those of control rats (n = 12).Most conventional echocardiographic variables demonstrated that RVHF rats have significant RV dysfunction. The area under the curve (AUC) values to distinguish RV dysfunction in RVHF rats from normal RV function in control rats using fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), peak tissue Doppler tricuspid annular velocities at systole (Sa), and at early diastole (Ea) were 0.71, 0.98, 0.79, 0.92, and 0.91, respectively. However, using STE analysis for RV evaluation, limited reproducibility was observed (variability 19-37 %, ICC 0.74-0.88) and the only circumferential strain showed significantly lower absolute values (P = 0.039, AUC = 0.76).To evaluate RV function in rat models, circumferential strain may be useful, however, the reproducibility and diagnostic utility were limited. Conventional echocardiographic variables such as TAPSE, tissue Doppler Sa, and Ea have superior diagnostic utility.

Relationship of Left Ventricular Diastolic Function to Obesity and Overweight in a Japanese Population With Preserved Left Ventricular Ejection Fraction

BACKGROUND Obesity has been found to be associated with future development of diastolic heart failure. Other evidence has indicated that the effect of obesity on left ventricular (LV) mass varies among ethnicities. However, there are few data on the relationship between body mass index (BMI) and LV diastolic dysfunction in the Japanese population. METHODSANDRESULTS We performed echocardiography in 788 subjects without valvular disease or LV systolic dysfunction. They were divided into 3 groups by BMI: normal weight, overweight, and obese. We used multivariable linear regression analysis to assess the clinical variables associated with diastolic parameters, including BMI. We also assessed the risk of diastolic dysfunction associated with BMI using multivariable logistic models. Overweight and obese subjects had significantly worse LV diastolic function and greater LV mass than normal weight subjects. In the multivariable analysis, BMI was independently associated with diastolic parameters. Furthermore, after adjusting for clinical factors, the increased risks of diastolic dysfunction in overweight subjects (adjusted odds ratio: 2.02, 95% confidence interval 1.21-3.36) and obese subjects (4.85, 3.36-16.27) were greater than those previously observed in Western populations. CONCLUSIONS The Japanese population might be more susceptible than Western subjects to the effect of BMI on LV diastolic function. Differences between ethnicities should be taken into consideration in strategies for the prevention of diastolic heart failure. (Circ J 2016; 80: 1951-1956).

Factors influencing left atrial volume in a population with preserved ejection fraction: Left ventricular diastolic dysfunction or clinical factors?

BACKGROUND Increased left atrial volume (LAV) predicts a higher incidence of cardiovascular events and is widely recognized as a major surrogate marker of left ventricular (LV) diastolic dysfunction (DD). Although the pathophysiology of LA enlargement is probably multifactorial, few studies have examined comprehensively the clinical factors that lead to LA enlargement in the absence of valvular disease or LV systolic dysfunction. Therefore, we investigated associations between LAV and several clinical and echocardiographic parameters including DD. METHODS We enrolled 557 subjects without significant valve disease or LV systolic dysfunction from the health check-up clinic retrospectively. We performed univariable and multivariable linear regression using lnLAV index as the dependent variable and the following independent variables: gender, age, smoking status, drinking habit, hypertension, diabetes, body mass index (BMI), LV ejection fraction, DD, LV mass index, hemoglobin, serum creatinine, serum total cholesterol, serum uric acid, serum sodium, and serum iron. RESULTS In multivariable analysis, LAV index was independently associated with BMI, lower hemoglobin, and moderate and severe DD compared with normal diastolic function (p<0.001), but not with mild DD (p=0.70). CONCLUSIONS LA enlargement was independently associated with moderate and severe DD, but not with mild DD. Furthermore, obesity and lower hemoglobin were associated with LAV independently of DD.

Prognostic impact of venous thromboembolism in patients with Duchenne muscular dystrophy: Prospective multicenter 5-year cohort study

Please cite this article as: Kimura Koichi, Morita Hiroyuki, Daimon Masao, Kawata Takayuki, Nakao Tomoko, Lee Seitetsu L., Hirokawa Megumi, Ebihara Aya, Nakajima Takashi, Ozawa Tetsuo, Yonemochi Yosuke, Aida Izumi, Motoyoshi Yasufumi, Mikata Takashi, Uchida Idai, Komori Tetsuo, Kitao Ruriko, Nagata Tetsuya, Takeda Shin’ichi, Komaki Hirofumi, Segawa Kazuhiko, Takenaka Katsu, Komuro Issei, Prognostic Impact of Venous Thromboembolism in Patients with Duchenne Muscular Dystrophy: Prospective Multicenter 5-Year Cohort Study, International Journal of Cardiology (2015), doi: 10.1016/j.ijcard.2015.04.244

Early Postoperative Outcome of Off-Pump Coronary Artery Bypass Grafting: A Report from the Highest-Volume Center in Japan

BACKGROUND Off-pump coronary artery bypass grafting (OPCAB) has evolved into a standard technique in coronary artery bypass grafting. However, a detailed investigation in Japanese population undergoing OPCAB has not yet been fully elucidated. METHODS A total of 1109 consecutive patients undergoing isolated OPCAB between 2006 and 2013 at Juntendo University were reviewed. The data was evaluated in the light of previously published OPCAB-associated reports. RESULTS There were 904 male (81.5%) and a mean was 67.5 ± 9.8 years. Eight patients (0.5%) died within 30 days postoperatively or before discharge, which was equivalent to or rather better than the previously reported mortality rates, including the European System for Cardiac Operation Risk Evaluation II (2.1 ± 2.1) data. A morbidity analysis revealed that prolonged intubation (>24 h) occurred in 43 patients (3.6%), surgical site infections in 18 (1.9%), neurological complications in 13 (1.3%). A reduced preoperative left ventricular ejection fraction (less than 40%) was found to be a risk factor for early postoperative death (odds ratio 10.58, respectively, p <0.05) in our cohort. CONCLUSIONS Early postoperative mortality and morbidity rates in Japanese population after OPCAB were rather satisfactory and similar to those reported by other countries.

When and how aortic stenosis is first diagnosed: A single-center observational study

BACKGROUND The development of clinical symptoms is associated with cardiovascular events in patients with aortic stenosis (AS). Thus, early diagnosis of AS is clinically important. However, there are few data on symptom status or the severity of AS when patients are first diagnosed, or on how AS is detected in routine practice. We aimed to investigate when and how AS patients are first diagnosed in our hospital. METHODS We retrospectively enrolled 198 AS patients diagnosed from 1989 to 2009, and identified their symptoms and AS severity at the time of the first diagnosis. We also assessed the reasons why they came to the hospital based on their medical records. RESULTS Of the 198 patients, 82 (41.6%) had voluntarily visited or been referred to our hospital after developing clinical symptoms (Symptomatic group). The remaining 116 patients (58.4%) had been asymptomatic, and cardiovascular disease was suspected during an annual or occasional health checkup (Asymptomatic group). The initial findings in the Asymptomatic group that led to the diagnosis of AS were: a systolic murmur on auscultation (62%), abnormal electrocardiography (27%), or abnormal echocardiography (11%). The Symptomatic group had significantly greater AS severity and an increased left ventricular mass index, and experienced more cardiac events (valve replacement or cardiac death) during the follow-up period. CONCLUSIONS About 40% of the AS patients in this study were not diagnosed until they developed clinical symptoms, suggesting that many other patients in the community might have a latent risk of cardiovascular events. Auscultation plays an important role in the early diagnosis of AS.

Reconsideration of Inferior Vena Cava Parameters for Estimating Right Atrial Pressure in an East Asian Population ― Comparative Simultaneous Ultrasound-Catheterization Study ―

BACKGROUND Ultrasound measurements of the inferior vena cava (IVC) diameter (IVCD), together with its respiratory variation, provide a noninvasive estimate of right atrial pressure (RAP). However, there is a paucity of studies that have compared this technique with simultaneous catheterization. We explored the best cut-off values of IVC parameters for elevated RAP in comparison with RAP measured by catheterization.Methods and Results:We prospectively enrolled 120 East Asian patients who were scheduled for catheterization. The IVCD and IVC collapsibility index (IVCCI) were measured according to the current guidelines. The optimal maximum IVCD (IVCDmax) and IVCCI cut-offs for detecting elevated RAP (RAP ≥10 mmHg) were 17 mm and 40%, respectively. When we combined both in proportion to the guidelines, the sensitivity and specificity for detecting elevated RAP were 75% and 94%, respectively. When the cut-off values from the current guidelines (>21 mm and <50%) were applied, the respective sensitivity and specificity were 42% and 99%. Interestingly, the cut-off value of the optimal IVCDmax indexed by body surface area (11 mm/m2) was similar to previous Western population data. When we combined both cut-off values (11 mm/m2and 40%), the sensitivity and specificity were 75% and 95%, respectively. CONCLUSIONS The optimal absolute IVCDmax and IVCCI cut-offs to detect elevated RAP were smaller than those in the current guidelines. Indexed IVCDmax may be an IVC parameter that can be used internationally.