Hitoshi Sawada

Noninvasive assessment of left and right ventricular filling in myocardial infarction with a two-dimensional Doppler echocardiography method

Inflow characteristics of left and right ventricular filling were assessed in 40 patients with myocardial infarction and in 10 normal subjects by pulsed Doppler echocardiography. Patients with myocardial infarction were subdivided into four groups, focusing on the involvement of right ventricular and septal branches of the coronary arteries. Group I consisted of 11 patients with anterior infarction who showed an obstructive lesion of the proximal left anterior descending branch involving the first septal perforator with a patent right coronary artery. Group II consisted of 10 patients with inferior infarction who showed an obstructive lesion of the proximal right coronary artery involving the right ventricular branch. Group III consisted of 12 patients with both anterior and inferior infarction who showed obstructive lesions of both the proximal left anterior descending branch and the right coronary artery involving the right ventricular branch. Group IV consisted of seven patients with lateral infarction who showed an obstructive lesion of the diagonal branch or branches of the circumflex coronary artery with a patent left anterior descending branch and right coronary artery. Three measurements were performed from the transmitral and transtricuspidal inflow velocity patterns to assess the left and right ventricular diastolic behaviors. These measurements were: acceleration half-time, deceleration half-time of early diastolic rapid inflow, and the ratio of the peak velocity of early diastolic rapid inflow to that of the late diastolic inflow due to the atrial contraction. Impaired diastolic filling of the left ventricle compensated by enhanced left atrial contraction was observed in patients with myocardial infarction from groups I, II, III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)

A new echocardiographic method for identifying vortex flow in the left ventricle: numerical validation.

A new mathematical method for estimating velocity vectors from color Doppler datasets is proposed to image blood flow dynamics; this method has been called echodynamography or vector flow mapping (VFM). In this method, the concept of stream function is exploited to expand a 2-D distribution of radial velocities in polar coordinates, observed with color Doppler, to a 2-D distribution of velocity vectors. This study was designed to validate VFM using 3-D numerical flow models. Velocity fields were reconstructed from the virtual color Doppler datasets derived from the models. VFM captured the gross features of flow structures and produced comparable images of the distribution of vorticity, which correlated significantly with the original field (for velocity magnitudes, standard error of estimate = 0.003 to 0.007 m/s; for vorticity, standard error of estimate = 0.35 to 2.01/s). VFM may be sensitive for depicting flow structures derived from color Doppler velocities with reasonable accuracy.

Three dimensional reconstruction of the left ventricle from multiple cross sectional echocardiograms. Value for measuring left ventricular volume.

The accuracy of a system for reconstructing a three dimensional image of the left ventricle from randomly recorded multiple short axis images was tested by comparing the calculated left ventricular volume with the directly measured left ventricular volume in 11 excised porcine hearts. The system comprised a real time phased array sector scanner, a transducer locating system, and a computer system for digitising outlines of the left ventricle, displaying the reconstruction image, and calculating the left ventricular volume. The reconstructed image was similar to the real image and the calculated left ventricular volume showed a high correlation with the directly measured left ventricular volume. This method was accurate in vitro and is expected to be available for clinical measurement of left ventricular volume.

Usefulness of Frequent Supraventricular Extrasystoles and a High CHADS2 Score to Predict First-Time Appearance of Atrial Fibrillation

Frequent supraventricular extrasystoles (SVEs) are associated with the subsequent first-time appearance of atrial fibrillation (AF) and ischemic stroke. The aim of this study was to investigate the combined role of SVEs and an AF-related risk score for ischemic stroke, the CHADS2 score, on the occurrence of new AF in patients in sinus rhythm. The Shinken Database 2004-2010 lists 3,263 patients who underwent 24-hour Holter monitoring. A total of 2,589 patients were analyzed, after excluding 674 patients previously diagnosed with AF. Frequent SVEs were defined as ≥102 beats/day (the top quartile) and the presence of a clinical background for a CHADS2 score ≥2 points as a high CHADS2 score. During the mean follow-up period of 571.4 ± 606.4 days, new AF occurred in 38 patients (9.4 per 1,000 patient-years). The incidence of new AF was 2.7 and 37.7 per 1,000 patient-years for patients with nonfrequent SVEs (<102 beats/day) and low CHADS2 scores and those with frequent SVEs and high CHADS2 scores, respectively. Multivariate Cox regression analysis showed that the hazard ratio for frequent SVEs and a high CHADS2 score compared with nonfrequent SVEs and a low CHADS2 score was 9.49 (95% confidence interval 3.20 to 28.15, p <0.001), even after adjustment for gender, age, medications, and echocardiographic parameters. In conclusion, frequent SVEs and a high CHADS2 score independently and synergistically predict the first-time appearance of AF in patients in sinus rhythm, indicating an approximately 10-fold higher risk. Patients meeting these criteria should have more aggressive early intervention for preventing AF.

Obesity paradox in Japanese patients after percutaneous coronary intervention: An observation cohort study

BACKGROUND The impact of obesity on Japanese patients who undergo primary percutaneous coronary intervention (PCI) remains unclear. METHODS AND RESULTS Within a single hospital-based cohort in the Shinken Database 2004-2010, which comprised all new patients (n=15227) who visited the Cardiovascular Institute, we followed patients who underwent PCI. Major adverse cardiac events (MACE)-death, myocardial infarction, or target lesion revascularization (TLR)-were defined as the composite endpoint. A total of 1205 patients were included in this study (median follow-up of 1037±703 days): 92 lean [body-mass-index (BMI)<20]; 640 normal-weight (BMI=20-24.9); 417 overweight (BMI=25-29.9); and 56 obese (BMI≥30). Mean age decreased and male gender increased with increasing BMI. Classic coronary risk factors were more common in overweight and obese patients than in normal-weight and lean patients. Chronic kidney disease (CKD) was more common in lean patients than in overweight and obese patients. Patients taking dual antiplatelet therapy, statins, beta-blockers, and renin-angiotensin-system inhibitors increased in a BMI-dependent manner. Obese patients had a significantly lower frequency of MACE, all-cause death, cardiac death, and hospital admission for heart failure than lean patients. Multivariate analysis showed that BMI category was independently associated with all-cause death after PCI. CONCLUSION Over-weight and obese patients were independently associated with favorable long-term clinical outcomes after PCI, suggesting that obesity paradox was applicable to Japanese patients after PCI in real-world clinical setting.

Recent mortality of Japanese patients with atrial fibrillation in an urban city of Tokyo.

BACKGROUND In Japan, the recent status of the mortality of atrial fibrillation (AF) patients is still unclear. METHODS AND RESULTS We used a single-hospital based cohort database in an urban city (Tokyo) in Japan, including all the new visitors from 2004 to 2009 (n=13,228). The non-adjusted death rates of AF patients for all-cause, stroke, and cardiovascular death were 1091, 97, and 727 per 100,000 patient-years, and the age-adjusted ones were 317 (95% CI, 316-318), 16 (95% CI, 16-16), and 238 (95% CI, 237-239), respectively. The age-adjusted relative risk of AF on all-cause mortality was 1.7 in the particular population. CONCLUSIONS The present study provides the most recent data about the characteristics and the mortality of AF patients in Tokyo, thus serving as the basic information for finding problems to solve regarding Japanese AF patients.

Clinical characteristics and long-term clinical outcomes of Japanese heart failure patients with preserved versus reduced left ventricular ejection fraction: A prospective cohort of Shinken Database 2004–2011

BACKGROUND Clinical data on the mortality and morbidity of unselected Japanese patients with heart failure (HF) are limited. In this study, we aimed to determine the clinical characteristics, long-term outcomes, and prognostic factors of Japanese HF patients with preserved or reduced left ventricular ejection fraction (LVEF). METHODS AND RESULTS We used a single hospital-based cohort from the Shinken Database 2004-2011 that comprised all new patients (n=17,517) visiting the Cardiovascular Institute Hospital. A total of 1,525 patients diagnosed with symptomatic HF at the initial visit were included in the analysis. Of these, 1121 patients (74%) exhibited a preserved LVEF (>50%) and 404 patients (26%) had a reduced LVEF (≤ 50%). HF patients with preserved LVEF (HFpEF) were older and more often female than patients with reduced LVEF (HFrEF). Kaplan-Meier curves and log-rank test results showed that HFpEF patients had a better prognosis than HFrEF patients. However, there were no significant differences in clinical outcomes between HFpEF and HFrEF patients when the analysis was limited to inpatients. Cox regression analysis showed that HFpEF patients had a significantly lower risk of all-cause death (p=0.027; hazard ratio, 0.547, 95% confidence interval, 0.321-0.933). Multivariate analyses performed separately showed that the independent predictors of all-cause death in HFrEF were advanced age, lower body mass index, diabetes mellitus, and the absence of statin treatment, whereas those for HFpEF were advanced age, absence of dyslipidemia, anemia, and left ventricular hypertrophy. CONCLUSIONS This prospective cohort study identified the clinical characteristics, long-term outcomes, and prognostic factors of Japanese HF patients with reduced and preserved ejection fractions in a real-world clinical setting.

Effects of statin treatment in patients with coronary artery disease and chronic kidney disease.

Statins reduce cardiovascular morbidity and mortality from coronary artery disease (CAD). However, the effects of statin therapy in patients with CAD and chronic kidney disease (CKD) remain unclear. Within a single hospital-based cohort in the Shinken Database 2004–2010 comprising all patients (n = 15,227) who visited the Cardiovascular Institute, we followed patients with CKD and CAD after percutaneous coronary intervention (PCI). A major adverse cardiovascular and cerebrovascular event (MACCE) was defined by composite end points, including death, myocardial infarction, cerebral infarction, cerebral hemorrhage, and target lesion revascularization. A total of 391 patients were included in this study (median follow-up time 905 ± 679 days). Of these, 209 patients used statins. Patients with statin therapy were younger than those without. Obesity and dyslipidemia were more common, and the glomerular filtration rate (GFR) was significantly higher, in patients undergoing statin treatment. MACCE and cardiac death tended to be less common, and all-cause death was significantly less common, in patients taking statins. Multivariate analysis showed that low estimated GFR, poor left ventricular ejection fraction, and the absence of statin therapy were independent predictors for all-cause death of CKD patients after PCI. Statin therapy was associated with reduced all-cause mortality in patients with CKD and CAD after PCI.

Impact of aging on the clinical outcomes of Japanese patients with coronary artery disease after percutaneous coronary intervention

Japan has become an aging society, resulting in an increased prevalence of coronary artery disease. However, clinical outcomes of elderly Japanese patients after percutaneous coronary intervention (PCI) remain unclear. Of the 15,227 patients in the Shinken Database, a single-hospital-based cohort of new patients, 1,214 patients who underwent PCI, was evaluated to determine the differences in clinical outcomes between the elderly (≥75 years) (n = 260) and the non-elderly (<75 years) (n = 954) patients. A major adverse cardiac event (MACE) was defined as a composite end point, including all-cause death, myocardial infarction (MI), and target lesion revascularization. Male gender and obesity were less common, and the estimated glomerular filtration rate (eGFR) was significantly lower in the elderly than in the non-elderly. Left ventricular ejection fraction (LVEF) was comparable between these groups. Left main trunk disease and multivessel disease were more common in the elderly than in the non-elderly group. Occurrence of MACE was frequent, and the incidences of all-cause death, cardiac death, and the admission rate for heart failure were significantly higher in the elderly patients. Multivariate analysis showed that prior MI, low eGFR, and poor LVEF were independent predictors for all-cause death in the elderly patients. Elderly patients had worse clinical outcomes than the non-elderly patients. Low eGFR and LVEF were independent predictors of all-cause death after PCI, suggesting that left ventricular dysfunction and renal dysfunction might synergistically contribute to the adverse clinical outcomes of the elderly patients undergoing PCI.

A New Scoring System for Evaluating the Risk of Heart Failure Events in Japanese Patients With Atrial Fibrillation

Risk stratification for heart failure (HF) in patients with atrial fibrillation (AF) has not been well established. The aim of this study was to identify the predictors of HF events in patients with AF, consequently developing a new risk-scoring system that stratifies the risk for HF events. In this prospective, single hospital-based cohort, all patients who presented from July 2004 to March 2010 were registered (Shinken Database 2004-2009). Follow-up was maintained by being linked to the medical records or by sending study documents of prognosis. Of the 13,228 patients in the Shinken Database 2004-2009, 1,942 patients with AF were identified. Of the patients with AF, HF events (hospitalization or death from HF) occurred in 147 patients (7.6%) during a mean follow-up period of 776 ± 623 days. After identifying the parameters that were independently associated with the incidence of HF events (coexistence of organic heart diseases, anemia [hemoglobin level <11 g/dl], renal dysfunction [estimated glomerular filtration rate <60 ml/min/m(2)], diabetes mellitus, and the use of diuretics), a new scoring system was developed, the H(2)ARDD score (heart diseases = 2 points, anemia = 1 point, renal dysfunction = 1 point, diabetes = 1 point, and diuretic use = 1 point; range 0 to 6 points). This scoring system discriminated the low- and high-risk populations well (incidence in patients scoring 0 and 6 points of 0.2% and 40.8% per patient-year, respectively) and showed high predictive ability (area under the curve 0.840, 95% confidence interval 0.803 to 0.876). In conclusion, the new H(2)ARDD score may help identify the population of patients with AF at high risk for HF events.