Mitsunobu Kitamura

Acute kidney injury and outcomes in acute decompensated heart failure: evaluation of the RIFLE criteria in an acutely ill heart failure population

The clinical course including the outcome of acute decompensated heart failure (ADHF) correlates with renal dysfunction, but the evaluation of renal function has not yet been standardized. We therefore investigated the relationship between the prognosis of ADHF and acute kidney injury (AKI) evaluated using the risk, injury, failure, loss, end stage (RIFLE) criteria.

Predicting the success of noninvasive positive pressure ventilation in emergency room for patients with acute heart failure

BACKGROUND Non-invasive positive pressure ventilation (NPPV) for acute heart failure (AHF) is increasingly used to avoid endotracheal intubation (ETI). We therefore reviewed our experience using respirator management in the emergency room for AHF, and evaluated the predictive factors in the success of NPPV in the emergency room. METHODS AND RESULTS Three-hundred forty-three patients with AHF were analyzed. The AHF patients were assigned to either BiPAP-Synchrony (B-S; Respironics, Merrysville, PA, USA) period (2005-2007, n = 176) or BiPAP-Vision (B-V; Respironics) period (2008-2010, n = 167). The rate of carperitide use was significantly increased and dopamine use was significantly decreased in the B-V period. The total length of hospital stay was significantly shorter in the B-V period. AHF patients were also assigned to a failed trial of NPPV followed by ETI (NPPV failure group) or an NPPV success group in the emergency room for each period. NPPV was successfully used in 48 cases in the B-S period, and in 111 cases in the B-V period. Fifty-seven ETI patients included 45 direct ETI and 11 NPPV failure cases in the B-S period, and 16 ETI patients included 10 direct ETI and 6 NPPV failure cases in the B-V period. The pH values were significantly lower in the NPPV failure than in the NPPV success for both periods (7.19 ± 0.10 vs. 7.28 ± 0.11, B-S period, p < 0.05; 7.05 ± 0.08 vs. 7.27 ± 0.14, B-V period, p < 0.001). A pH value of 7.20 produced the optimal balance in the B-S period, while that of 7.03 produced the optimal balance in B-V periods by the ROC curve analysis. The cutoff value of pH was lower in the B-V period than in the B-S period. CONCLUSIONS This predictive value provides successful estimates of NPPV with a high sensitivity and specificity, and the aortic blood gas level was above 7.03 pH when using the B-V system.

Delayed enhancement magnetic resonance imaging in hypertrophic cardiomyopathy with Basal septal hypertrophy and preserved ejection fraction: relationship with ventricular tachyarrhythmia.

Objective This study aimed to determine the relationship between delayed enhancement magnetic resonance imaging (DE MRI) and ventricular tachyarrhythmia in patients with hypertrophic cardiomyopathy (HCM) with basal septal hypertrophy and preserved ejection fraction (EF). Methods One hundred seven patients with HCM with basal septal hypertrophy and EF greater than 50% underwent cine and DE MRI. Myocardial scar was identified with DE MRI. We assessed whether patient,s background, cine MRI findings, presence of myocardial scar, or number of scarred myocardial segments was related to the occurrence of ventricular tachyarrhythmia. Results Patient,s age, family history of HCM, and number of scarred segments differed between the patients with and without the arrhythmia. A family history of HCM and number of scarred segments were significantly related to ventricular tachyarrhythmia (P < 0.01). Conclusions The number of scarred segments is the significant DE MRI parameter related to ventricular tachyarrhythmia in HCM with basal septal hypertrophy and preserved EF.

High-sensitivity cardiac troponin T for earlier diagnosis of acute myocardial infarction in patients with initially negative troponin T test--comparison between cardiac markers.

BACKGROUND AND PURPOSE An early diagnosis is essential for therapeutic decision and risk stratification in patients with suspected acute myocardial infarction (AMI). We analyzed and compared the diagnostic value of high-sensitivity troponin T (hs-TnT) and other cardiac markers in patients with an initially negative troponin T test at presentation. METHODS AND SUBJECTS The present study was a prospective, multicenter study including five participating emergency cardiovascular tertiary centers in Japan. From November 2009 through January 2011, patients with suspected AMI at the emergency room with an initial troponin T (c-TnT) test <100 ng/L were enrolled. RESULTS A total of 85 patients were prospectively assigned from five participating emergency cardiovascular tertiary centers in Japan. The median time from the onset of chest pain to the T0 sampling was 165 min [IQR 120-180]. The final diagnoses according to the recent universal definition and other standard cut-off values were AMI in 47, unstable angina in 12, and non AMI in 38 patients. The overall ROC-AUC value of hs-TnT, c-TnT, creatine kinase MB, and heart-type fatty acid-binding protein were 0.810, 0.716, 0.782, and 0.880, respectively. The diagnostic sensitivity and negative predictive value of hs-TnT were both 100% for the patients admitted more than 120 min from the onset, however the specificity was limited for the whole time-windows (71%). The absolute value change of the hs-TnT from T0 to T3 sampling 3h later improved the ROC-AUC up to 0.972 and the specificity was 92% at 22 ng/L (ROC-optimized cut-off) and 100% at 105 ng/L (rule-in cut-off). CONCLUSIONS The hs-TnT displayed 100% sensitivity and negative predictive value for the patients admitted more than 120 min from the onset, however the specificity was limited. The absolute change from T0 to T3 (22 ng/L) improved the total diagnostic performance.

Distribution and Clinical Significance of High Signal Intensity of the Myocardium on T2-Weighted Images in 2 Phenotypes of Hypertrophic Cardiomyopathy.

Objective The aim of this study was to evaluate distribution and clinical significance of high signal intensity of the myocardium on T2-weighted images (T2-HI) in 2 phenotypes of hypertrophic cardiomyopathy (HCM). Methods Thirty-six patients with asymmetrical septal HCM (ASH) and 18 patients with apical HCM (APH) and their 864 myocardial segments were investigated. The distribution of T2-HI was compared with that of late gadolinium enhancement (LGE), and the relationships between T2-HI and clinical risk markers were evaluated. T2 values of the T2-HI were estimated with T2 mapping. Results The T2-HI was observed in 18 segments (3.1%) in 13 patients with ASH (36.1%) and in 12 segments (4.2%) in 8 patients with APH (44.4%). It was often localized outside LGE. The presence of T2-HI was related to syncope in ASH (P = 0.016). Furthermore, it had higher T2 values (61.1 milliseconds) than the reference myocardium (47.3 milliseconds). Conclusions High signal intensity of the myocardium on T2-weighted images often locates outside LGE and reflects myocardial damage, which is related to syncope in ASH.

Prognostic values of highly sensitive cardiac troponin T and B-type natriuretic peptide for clinical features in hypertrophic obstructive cardiomyopathy: a cross-sectional study

Objectives Although B-type natriuretic peptide (BNP) and highly sensitive cardiac troponin T (cTnT) are useful for the evaluation of clinical features in various cardiovascular diseases, there are comparatively few data regarding the utility of these parameters in patients with hypertrophic obstructive cardiomyopathy (HOCM). The goal of this study was to assess the association between BNP, cTnT and clinical parameters in patients with HOCM. Design Cross-sectional survey Settings The relationship between BNP, cTnT and clinical end points and echocardiographic data was investigated. Participants This study included 102 consecutive outpatients with HOCM who were clinically stable. Results BNP was significantly associated with both maximum left ventricular (LV) wall thickness (r=0.28; p=0.003), and septal peak early transmitral filling velocity/peak early diastolic mitral annulus velocity (r=0.51; p=0.0001). No statistically significant associations were seen between cTnT and any echocardiographic parameters, but the presence of atrial fibrillation (AF) was associated with a high level of cTnT (p=0.01). Conclusions BNP is useful for monitoring clinical parameters and as a reflection of both LV systolic/diastolic function and increased LV pressure in patients with HOCM. A high level of serum cTnT is associated with the presence of AF.

Myocardial fibrosis evaluated by look–locker and late gadolinium enhancement magnetic resonance imaging in apical hypertrophic cardiomyopathy: Association with ventricular tachyarrhythmia and risk factors

To evaluate the distribution and extent of myocardial fibrosis identified by either contrast‐enhanced Look–Locker or late gadolinium enhancement magnetic resonance imaging (LGE MRI) and their relationships between ventricular tachyarrhythmia or risk factors in apical hypertrophic cardiomyopathy (APH).

Clinical Characteristics and Outcome of Alcohol Septal Ablation With Confirmation by Nitroglycerin Test for Drug-Refractory Hypertrophic Obstructive Cardiomyopathy With Labile Left Ventricular Outflow Obstruction.

Careful evaluation, including provocation tests, is needed to specify an indication for septal reduction therapy in patients with drug-refractory hypertrophic obstructive cardiomyopathy. This study aimed to evaluate the outcome of alcohol septal ablation (ASA) using an intravenous nitroglycerin test (IV-NTG). Of consecutive 156 patients, after excluding cases of severe valvular disease and repeat septal reduction therapy, we investigated the clinical characteristics of patients with labile obstruction (n = 32) and the outcomes after ASA using the IV-NTG test; comparisons were made with those exhibiting basal obstruction (a resting gradient of ≥30 mm Hg). The patients with labile obstruction had less left ventricular mass (141 ± 47 vs 182 ± 59 g, p = 0.003) and less brain natriuretic peptide values (414 ± 576 vs 744 ± 625 pg/ml, p <0.001) than those with basal obstruction. Immediately after ASA, the gradients improved from 15 ± 7 to 5 ± 5 mm Hg and the IV-NTG-provoked gradients improved from 74 ± 25 to 13 ± 9 mm Hg, respectively. At 1-year follow-up, the New York Heart Association functional class had improved from 2.7 ± 0.5 to 1.3 ± 0.5. There was no sudden cardiac death during the follow-up period (5.1 ± 3.0 years), and 8-year survival free from cardiovascular death was 94%. In conclusion, patients with labile obstruction had less-severe left ventricular hypertrophy but exhibited symptoms comparable to those with basal obstruction. The IV-NTG test is a useful method for rapidly confirming acute reduction of the latent gradient after the ASA procedure, and the outcome of ASA for labile obstruction was favorable.

Magnetic resonance imaging of microvascular obstruction in hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation

Background The clinical significance of microvascular obstruction (MO) in hypertrophic cardiomyopathy (HOCM) after percutaneous transluminal septal myocardial ablation (PTSMA) remains unknown. Purpose To assess the relationship between the location of MO and the improvement in symptoms and pressure gradient after PTSMA in patients with HOCM. Material and Methods Twenty-three patients with HOCM underwent MRI within 24 weeks after PTSMA. The MO was defined visually as the hypointense region adjacent to the left or right ventricular cavity, which was surrounded by myocardial infarction. The location of MO and improvement in clinical symptoms and pressure gradient at 3–6 months follow-up were assessed. Results MO was observed in 16 patients who underwent MRI within 7 weeks after PTSMA. Left-sided MO was observed in 12 patients, and right-sided MO was observed in four patients. Improvement in clinical symptoms and reduction in the pressure gradient were not sufficient in the patients with right-sided MO, while PTSMA was effective in the patients with the left-sided MO. Conclusion The location of MO identified by MRI may be related to the effectiveness of PTSMA at the short-term follow-up. The left-sided MO is related to complete improvement in clinical symptoms and pressure gradients.

Contrast-enhanced Steady-state Free Precession in the Assessment of Hypertrophic Obstructive Cardiomyopathy after Alcohol Septal Ablation.

PURPOSE We evaluated the feasibility of contrast-enhanced steady-state free precession (ceSSFP) in the assessment of myocardial injury and obstruction of the left ventricular outflow tract (LVOT) in patients with hypertrophic obstructive cardiomyopathy (HOCM) after alcohol septal ablation (ASA). METHODS Twelve patients with HOCM underwent 16 magnetic resonance (MR) examinations following ASA. Precontrast SSFP, ceSSFP and late gadolinium enhancement (LGE) imaging were performed with a 1.5-tesla imager. ceSSFP was performed 3 to 7 min after gadolinium injection. We visually and quantitatively evaluated the signal patterns of the myocardium after ASA on SSFP and LGE MR imaging. We observed the LVOT using ceSSFP in the 3-chamber view. RESULTS We could visualize ASA-induced myocardial infarction (MI) in all 16 studies by LGE and ceSSFP but in only 6 studies (37.5%) by precontrast SSFP. Contrast was higher between MI and remote myocardium with LGE than ceSSFP (P < 0.01). ASA-induced hypointense regions were well visualized by the 2 sequences after contrast in the 7 patients who underwent MR imaging within 7 weeks of ASA and in a few patients after 80 weeks from ASA. The ceSSFP allowed comparable visualization of the jet flow crossing the LVOT to that derived from echocardiographic data. CONCLUSION Contrast-enhanced steady-state free precession allows assessment of myocardial injury as well as of the left ventricular outflow tract after alcohol septal ablation in a single scan without penalty in scan time and cine imaging contrast.