Shinji Nakao

Symptomatic ventricular tachyarrhythmia is associated with delayed gadolinium enhancement in cardiac magnetic resonance imaging and with elevated plasma brain natriuretic peptide level in hypertrophic cardiomyopathy

BACKGROUND Delayed gadolinium enhancement (DGE) in cardiac magnetic resonance (CMR) imaging indicates the areas with myocardial fibrosis, which are suggested to be arrhythmogenic substrate in hypertrophic cardiomyopathy (HCM). Elevated brain natriuretic peptide (BNP) is associated with cardiovascular events in HCM. We investigated the grade of DGE in CMR and plasma BNP levels in HCM patients with or without symptomatic ventricular tachycardia (VT) or ventricular fibrillation (VF). METHODS AND RESULTS We recruited 26 consecutive untreated HCM patients without any symptoms of heart failure. They were divided into 2 groups: (1) patients with symptomatic VT/VF [VT/VF(+) group, n=6]; (2) patients without symptomatic VT/VF [VT/VF(-) group, n=20]. CMR was performed to evaluate left ventricular geometry and the grade of DGE. Plasma BNP levels, left ventricular mass index, and the number of segments with positive DGE were greater in the VT/VF(+) group than in the VT/VF(-) group (698.1+/-387.6 vs. 226.9+/-256.8 pg/ml, p=0.006; 152.3+/-49.5 vs. 89.5+/-24.1 g/m(2), p=0.003; 9.7+/-5.7 vs. 3.5+/-3.3, p=0.013). On logistic regression, adjusted odds ratio for symptomatic VT/VF was 214 for logBNP (95% confidence interval [CI] 1.2-37,043, p=0.04) and 1.54 for DGE score (95% CI 1.01-2.34, p=0.04). CONCLUSIONS High plasma BNP levels and the enlarged area of DGE in CMR were associated with symptomatic ventricular tachyarrhythmia. These factors may be useful markers for detecting high-risk patients of sudden cardiac death in HCM.

Matrix metalloproteinase-1 and -2 levels are differently regulated in acute exacerbation of heart failure in patients with and without left ventricular systolic dysfunction.

Matrix metalloproteinases (MMPs) play important roles in progression of chronic heart failure (HF) by regulating cardiac extracellular matrix metabolism. However, there is no report to investigate the difference of circulating MMP-1 and MMP-2 levels between systolic HF (SHF) and diastolic HF (DHF), particularly in light of acute exacerbation of HF. We assessed 110 HF patients who were admitted because of an acute exacerbation. They were divided into two groups: SHF [n = 68, left ventricular ejection fraction (LVEF) <45%] or DHF (n = 42, LVEF ≥45%). Ten patients without HF served as controls. Serum MMP-1 and MMP-2, and plasma brain natriuretic peptide (BNP) levels were examined on admission and at discharge. Serum MMP-1 level was higher on admission in both SHF and DHF than in controls. It was higher in SHF than in DHF and did not change at discharge in both groups. Serum MMP-2 level was equally higher on admission in SHF and DHF than in controls. It decreased in both groups at discharge. Treatment-induced changes in LVEF and BNP level correlated with those in MMP-2 level in SHF but not in DHF. Circulating MMP-1 and MMP-2 levels showed different dynamics between SHF and DHF in acute exacerbation and after treatment. These differences in circulating MMP-1 and MMP-2 levels may be related to the phenotype of HF.

Candida parapsilosis endocarditis that emerged 2 years after abdominal surgery.

A 22-year-old man was hospitalized after 3 months of persistent fever and malaise. He had undergone abdominal surgery 24 months before admission. Echocardiography demonstrated two mobile pedunculated masses in the right ventricle. Multiple blood cultures were positive for Candida parapsilosis. After 4 weeks of miconazole treatment, the two masses were excised via a right atriotomy incision and the transtricuspid value approach. Histological examination revealed that they were fungal vegetation. Antifungal agents were continued for 1 year after surgery. The patient has remained well with no further symptoms for 3 years. This case suggests the necessity for careful evaluation of past history to avoid diagnostic delay in fungal endocarditis.

Inappropriateness of ventricular hypertrophy is important as a determinant of BNP but not of diastolic filling in untreated hypertensive patients

Echocardiographically determined inappropriateness of left ventricular mass (LVM) is an independent risk factor for cardiovascular events. Although LV hypertrophy is associated with an increase in the plasma brain natriuretic peptide level and decreased LV diastolic filling, it is unknown whether the inappropriateness of LVM affects them. We studied 77 untreated hypertensive patients (49 men, 28 women, aged 59±12 years). The plasma brain natriuretic peptide level was measured, in addition to routine echo Doppler indexes of LV geometry and function. The appropriateness of LVM to cardiac workload was evaluated by the ratio of the observed LVM to the value predicted for individual sex, stroke work and height2.7 (oLVM/pLVM). Multivariate analysis showed that the plasma brain natriuretic peptide level increased with LVM index but decreased when oLVM/pLVM increased. The ratio of the peak early diastolic flow velocity of mitral flow to the peak early diastolic velocity of mitral annulus (E/E′) correlated not only with oLVM/pLVM but also with the LVM index (r=0.30, P<0.05; r=0.37, P<0.05, respectively). However, when a multiple stepwise regression analysis was carried out, only LVM index was determined to be a significant correlate of the E/E′ ratio, indicating that the inappropriateness of LVM does not affect the E/E′ ratio in hypertensive patients. Brain natriuretic peptide levels are influenced not only by the extent of LV hypertrophy but also by the inappropriateness of hypertrophy in untreated hypertensive patients. Diastolic filling is mostly affected by the extent of LV hypertrophy and not by the appropriateness of hypertrophy.