Hiroaki Kitaoka

Low dose dobutamine stress echocardiography predicts the improvement of left ventricular systolic function in dilated cardiomyopathy

OBJECTIVE To determine whether dobutamine stress echocardiography can predict the improvement of left ventricular systolic function in patients with dilated cardiomyopathy (DCM). METHODS Myocardial contractile reserve, as assessed by dobutamine stress echocardiography, was determined in 18 patients with DCM (mean (SD) age 53 (13) years, left ventricular ejection fraction (LVEF) 28 (10)%) and compared with changes in LVEF during a follow up period of 15 (8) months. The LVEF and regional left ventricular wall motion score (0, normal to 4, dyskinesis) of 12 segments in short axis and four chamber views were analysed before and after dobutamine infusion (5–20 μg/kg/min). RESULTS During a follow up period of 15 (8) months, a significant improvement in LVEF (> 20%) was found in seven patients but not in the remaining 11. Baseline haemodynamic findings were similar in both groups. Patients with an improvement in follow up LVEF showed a greater change in wall motion score from baseline during dobutamine infusion than patients with no improvement (at rest, 1.7 (0.4) v1.9 (0.2), NS; dobutamine 10 μg/kg/min, 0.6 (0.4)v 1.2 (0.4), p < 0.05). The percentage change in LVEF during dobutamine infusion was also significantly greater in patients who showed improvement than in those who did not. The change in LVEF during the follow up period (follow up LVEF/baseline LVEF) correlated well with the change in LVEF during dobutamine stress (LVEF at rest/LVEF at dobutamine 10 μg/kg/min;r = 0.74, p < 0.001). CONCLUSIONS Changes in left ventricular systolic performance during low dose dobutamine stress echocardiography are a useful marker to predict the outcome of left ventricular systolic function in patients with DCM.

Significance of high-sensitivity cardiac troponin T in hypertrophic cardiomyopathy.

OBJECTIVES This study investigated the significance of the serum high-sensitivity cardiac troponin T (hs-cTnT) marker for prediction of adverse events in hypertrophic cardiomyopathy (HCM). BACKGROUND Although serum cardiac troponins as sensitive and specific markers of myocardial injury have become well-established diagnostic and prognostic markers in acute coronary syndrome, the usefulness of hs-cTnT for prediction of cardiovascular events in patients with HCM is unclear. METHODS We performed clinical evaluation, including measurements of hs-cTnT in 183 consecutive patients with HCM. RESULTS Of 183 HCM patients, 99 (54%) showed abnormal hs-cTnT values (>0.014 ng/ml). During a mean follow-up of 4.1 ± 2.0 years, 32 (32%) of the 99 patients in the abnormal hs-cTnT group, but only 6 (7%) of 84 patients with normal hs-cTnT values, experienced cardiovascular events: cardiovascular deaths, unplanned heart failure admissions, sustained ventricular tachycardia, embolic events, and progression to New York Heart Association functional class III or IV status (hazard ratio [HR]: 5.05, p < 0.001). Abnormal hs-cTnT value remained an independent predictor of these cardiovascular events after multivariate analysis (HR: 3.23, p = 0.012). Furthermore, in the abnormal hs-cTnT group, overall risk increased with an increase in hs-cTnT value (HR: 1.89/hs-cTnT 1 SD increase in the logarithmic scale, 95% confidence interval: 1.13 to 3.15; p = 0.015 [SD: 0.59]). CONCLUSIONS In patients with HCM, an abnormal serum concentration of hs-cTnT is an independent predictor of adverse outcome, and a higher degree of abnormality in hs-cTnT value is associated with a greater risk of cardiovascular events.

Effect of left ventricular reverse remodeling on long-term prognosis after therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and β blockers in patients with idiopathic dilated cardiomyopathy.

It remains unknown whether left ventricular (LV) reverse remodeling (LVRR) after therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers and β blockers is correlated with prognosis in patients with idiopathic dilated cardiomyopathy. Forty-two patients with idiopathic dilated cardiomyopathy treated with the therapy were studied. Complete left ventricular reverse remodeling was defined as LV end-diastolic dimension ≤ 55 mm and fractional shortening ≥ 25% at the last echocardiographic assessment. The incidence of complete LVRR was significantly higher in patients who survived than in those who died or underwent heart transplantation. Patients were divided into 3 groups: death or transplantation, alive with complete LVRR, and alive without complete LVRR. Although patients who died or underwent transplantation did not show any LV improvements, those with complete LVRR showed significant improvements at 1 to 6 months after starting the therapy. Patients without complete LVRR also showed small but significant improvements at 1 to 6 months. The decrease in LV end-systolic dimension from the initial value to that at 1 to 6 months was an independent determinant of future cardiac death or transplantation. In conclusion, complete LVRR is related to favorable prognosis in patients with idiopathic dilated cardiomyopathy. The extent of left ventricular reverse remodeling at 1 to 6 months after starting the therapy is predictive of long-term prognosis.

Serum Cardiac Troponin I is Related to Increased Left Ventricular Wall Thickness, Left Ventricular Dysfunction, and Male Gender in Hypertrophic Cardiomyopathy

Serum cardiac troponin I (cTnI) is a sensitive and specific marker of myocardial injury. However, a systematic evaluation of cTnI in hypertrophic cardiomyopathy (HCM) patients has not been performed.

Influences of donepezil on cardiovascular system--possible therapeutic benefits for heart failure--donepezil cardiac test registry (DOCTER) study.

Abstract: To study prospectively influences of donepezil, an acetylcholinesterase inhibitor against Alzheimer disease, on cardiovascular system, we evaluated cardiovascular changes occurring during new initialized treatment with donepezil in 49 dementia patients over 6 months. No patient suffered from cardiovascular events. In clinical changes between baseline and the first evaluation after donepezil treatment, heart rate and plasma brain natriuretic peptide (BNP) levels as a marker for heart failure did not change (BNP: 59.62 ± 62.71 pg/mL at baseline to 53.18 ± 42.34 pg/mL at first evaluation; P = 0.262). We further examined plasma BNP levels in 2 groups into which the patients were divided at baseline according to the cut-off plasma BNP level of 60 pg/mL. In patients with high level of BNP, the BNP levels decreased after administration of donepezil (116.39 ± 76.58 pg/mL at baseline to 82.24 ± 46.64 pg/mL at first evaluation; P = 0.011) with the tendency to be reduced in the follow-up period. BNP did not change in patients with low level of BNP. Donepezil seemed to be safe in patients with dementia without symptomatic heart disease and significantly decreased plasma BNP levels in patients with subclinical chronic heart failure.

Gender-specific differences in the clinical features of hypertrophic cardiomyopathy in a community-based Japanese population: Results from Kochi RYOMA study

OBJECTIVES Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder with a broad spectrum of clinical features. Although gender may be one of the important modifying factors in HCM, there has been little information on gender differences. METHODS We investigated gender-specific differences in the clinical features of HCM in a community-based Japanese population. We established cardiomyopathy registration in Kochi Prefecture named Kochi RYOMA study consisting of 9 hospitals as an unselected regional Japanese population. RESULTS 261 patients with diagnosis of HCM were registered. At registration, 88 patients (34%) were women. Female patients were more frequently diagnosed as having HCM at ≥65 years (41% versus 27%) and had a higher ratio of familial HCM (35% versus 19%). More female patients had diagnosis of HCM due to cardiac symptoms (64% versus 40%) and were symptomatic both at diagnosis and at registration. Although the prevalence of atrial fibrillation was not different between males and females, embolic events occurred less frequently in female patients at registration than in male patients (2% versus 10%). In female patients, there were more obstructive HCM patients and fewer patients with apical HCM. Left ventricular and left atrial diameters were smaller and fractional shortening was higher in females than in males. CONCLUSIONS The manifestations of HCM in unselected Japanese patients differed in men and women, which suggest that hormonal, social, and genetic factors may influence the clinical presentation of HCM.

Left Ventricular Reverse Remodeling in Long-Term (>12 Years) Survivors With Idiopathic Dilated Cardiomyopathy

Little is known about left ventricular (LV) reverse remodeling (LVRR) in long-term survivors with idiopathic dilated cardiomyopathy. We studied 59 patients with idiopathic dilated cardiomyopathy who had a potential clinical and echocardiographic follow-up period of >12 years. LVRR was defined as LV end-diastolic dimension ≤ 55 mm and fractional shortening ≥ 25% on the last echocardiogram. Of the 59 patients, 38 died (heart failure in 20, sudden death in 11, and other causes in 7), 2 underwent transplantation, and 19 survived. In the survivors, the LV size had significantly decreased and LV fractional shortening had significantly increased on the last echocardiogram. LVRR occurred in 37% of the survivors. The remaining 63% of the survivors still had LV dysfunction, but the LV end-systolic dimension had decreased significantly. In patients who died or underwent transplantation, the LV size significantly increased. No patient who died or underwent transplantation had LVRR. In conclusion, >60% of the long-term (>12 years) survivors with idiopathic dilated cardiomyopathy still had LV systolic dysfunction, but the LV end-systolic dimension had decreased significantly. In contrast, patients who died or underwent transplantation had significant LV enlargement. These results suggest that LVRR, even if it is not marked, is associated with a favorable prognosis.

Delayed recovery of postexercise blood pressure in patients with chronic heart failure

Thirty-four patients with idiopathic dilated and ischemic cardiomyopathy underwent a symptom-limited cardiopulmonary exercise testing to evaluate the significance of postexercise blood pressure (BP) response. The postexercise BP response was useful in assessing the impaired exercise capacity and increased sympathetic activity in patients with heart failure.

Improvement in prognosis of dilated cardiomyopathy in the elderly over the past 20 years.

BACKGROUND AND PURPOSE Although dilated cardiomyopathy (DCM) had a poor prognosis in the past, recent studies have shown better survival. However, little is known about the improvement of prognosis in the elderly. This study sought to clarify the changes in prognosis in elderly patients with DCM over the past 20 years. METHODS AND SUBJECTS We studied 54 consecutive patients with DCM (38 men and 16 women, aged 65-83 years) who were diagnosed at over 65 years of age. The patients were divided into two groups (group A: 12 patients diagnosed before 1990; group B: 42 patients diagnosed after 1990) because after 1990, based on growing evidence from large-scale, randomized clinical studies, we intentionally increased the use of angiotensin-converting enzyme inhibitors (ACEI) and then beta-blockers at our hospital. RESULTS There were no significant differences in age, gender, NYHA functional class, and the prevalence of atrial fibrillation and ventricular tachycardia between the two groups. Left ventricular (LV) size assessed by echocardiography was larger (LV end-diastolic diameter, 67+/-5.9 versus 62+/-6.6 mm; p=0.039) and LV ejection fraction measured by left ventriculography was lower (ejection fraction, 24+/-9 versus 35+/-10%; p=0.004) in group A. ACEI/angiotensin II type 1 receptor blockers (ARB) (0% versus 88%) or beta-blockers (0% versus 52%) were more frequently used in group B. Antiarrhythmics (class Ia or Ib) (75% versus 14%) were less often used in group B. The 5- and 10-year event-free survival rates for cardiac death were 75.4% and 22.0% in group A versus 81.2% and 71.3% in group B (log-rank test, p=0.014). CONCLUSIONS The prognosis of DCM patients in the elderly has significantly improved over the past 20 years. The advances in the pharmacologic treatment and earlier diagnosis may have contributed to the better survival.

Serum tenascin-C levels as a prognostic biomarker of heart failure events in patients with hypertrophic cardiomyopathy

BACKGROUND AND PURPOSE Although serum tenascin-C (TN-C) levels are related to left ventricular (LV) remodeling in patients with myocardial infarction and are useful as a prognostic biomarker of heart failure in patients with dilated cardiomyopathy, the clinical significance of TN-C levels has not yet been studied in patients with hypertrophic cardiomyopathy (HCM). Therefore, the purpose of this study is to elucidate whether serum TN-C levels are a prognostic biomarker for heart failure in patients with HCM. METHODS The relationship between serum TN-C levels and heart failure events was studied in 36 patients with HCM during follow-up. RESULTS Levels of serum TN-C were 28±13 ng/ml (range 11-80 ng/ml). Although patients with LV systolic impairment showed higher TN-C levels than those with preserved LV systolic function (33±11 ng/ml vs. 27±14 ng/ml; p=0.16), TN-C levels were not related to any echocardiographic parameters. During the follow-up period of 4.8±1.4 years, heart failure events were observed in six patients and TN-C levels in patients with events were higher than those in patients without events. Kaplan-Meier analysis showed that the prognosis was worse in patients with high TN-C levels (≥39.2 ng/ml) than in those with low TN-C levels. CONCLUSIONS Heart failure events were more frequently observed in patients with high serum TN-C levels than in those with low TN-C levels. Serum TN-C levels may be a new prognostic biomarker for heart failure in patients with HCM.