Tatsuya Nakachi

Simple and Accurate Electrocardiographic Criteria to Differentiate Takotsubo Cardiomyopathy From Anterior Acute Myocardial Infarction

To the Editor: Because clinical features of Takotsubo cardiomyopathy (TC) mimic those of anterior acute myocardial infarction (AMI) ([1][1]), the differential diagnosis is important in selecting the appropriate treatment strategy, especially in the acute phase. This study assessed the value of the

Impairment of Coronary Flow Reserve Evaluated by Phase Contrast Cine‐Magnetic Resonance Imaging in Patients With Heart Failure With Preserved Ejection Fraction

Background Phase contrast (PC) cine‐magnetic resonance imaging (MRI) of the coronary sinus allows for noninvasive evaluation of coronary flow reserve (CFR), which is an index of left ventricular microvascular function. The objective of this study was to investigate coronary flow reserve in patients with heart failure with preserved ejection fraction (HFpEF). Methods and Results We studied 25 patients with HFpEF (mean and SD of age: 73±7 years), 13 with hypertensive left ventricular hypertrophy (LVH) (67±10 years), and 18 controls (65±15 years). Breath‐hold PC cine‐MRI images of the coronary sinus were obtained to assess blood flow at rest and during ATP infusion. CFR was calculated as coronary sinus blood flow during ATP infusion divided by coronary sinus blood flow at rest. Impairment of CFR was defined as CFR <2.5 according to a previous study. The majority (76%) of HFpEF patients had decreased CFR. CFR was significantly decreased in HFpEF patients in comparison to hypertensive LVH patients and control subjects (CFR: 2.21±0.55 in HFpEF vs 3.05±0.74 in hypertensive LVH, 3.83±0.73 in controls; P<0.001 by 1‐way ANOVA). According to multivariable linear regression analysis, CFR independently and significantly correlated with serum brain natriuretic peptide level (β=−68.0; 95% CI, −116.2 to −19.7; P=0.007). Conclusions CFR was significantly lower in patients with HFpEF than in hypertensive LVH patients and controls. These results indicated that impairment of CFR might be a pathophysiological factor for HFpEF and might be related to HFpEF disease severity.

Prognostic significance of quantitative assessment of focal myocardial fibrosis in patients with heart failure with preserved ejection fraction

BACKGROUND The aim of this study was to investigate the prognostic value of myocardial focal fibrosis quantified by late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) in patients with heart failure with preserved ejection fraction (HFpEF). METHODS One-hundred eleven HFpEF patients (mean age: 70 ± 14 years, 55 (50%) female) were enrolled. We excluded patients with previous history of coronary artery disease and/or ischemic pattern of hyper enhancement on LGE MRI. Myocardial enhancement was defined using signal intensity >2SD above the mean signal intensity of a remote myocardium. Major adverse cardiovascular events were defined as cardiovascular death and heart failure requiring hospitalization. RESULTS During a mean follow up period of 851 ± 609 days, 10 events (2 cardiovascular death, 8 hospitalization for heart failure decompensation) were observed. Area under the receiver operating characteristics curve of LGE% for the detection of future events was 0.721 (95% CI: 0.628-0.802). Multivariate Cox proportional hazard analysis showed that LGE% is an independent predictor of future events after the adjustment with prognostic 5 factors - age, diabetes mellitus, New York Heart Association classification, history of heart failure hospitalization and left ventricular ejection fraction - which were identified in the I-PRESERVE study (Irbesartan in Heart Failure with Preserved Ejection Fraction Study) (hazard ratio=7.913, 95% CI: 1.603-39.05, P=0.012). CONCLUSIONS Larger size of LGE was significantly associated with high rate of future cardiovascular death and heart failure hospitalization, suggesting that the quantification of myocardial focal fibrosis by LGE MRI could be useful for the risk stratification in HFpEF patients.

Glycemic Variability on Continuous Glucose Monitoring System Predicts Rapid Progression of Non-Culprit Lesions in Patients With Acute Coronary Syndrome

BACKGROUND Although rapid progression (RP) of coronary artery disease (CAD) has been shown to be a powerful predictor of cardiovascular events, predictors of RP are not fully understood in patients with acute coronary syndrome (ACS). METHODSANDRESULTS We prospectively investigated the clinical impact of glycemic variability (GV), as determined on continuous glucose monitoring system (CGMS), on RP of non-culprit lesions in 88 patients with ACS. RP was defined as ≥10% diameter reduction in a pre-existing stenosis ≥50%; ≥30% diameter reduction in a stenosis <50%; development of a new stenosis ≥30% in a previously normal segment; or progression of any stenosis to total occlusion. Patients were classified into 2 groups according to the presence (progressor, n=20) or absence (non-progressor, n=68) of RP. All patients were equipped with a CGMS during the stable phase, and mean amplitude of glycemic excursion (MAGE) was calculated as a marker of GV. Mean MAGE was significantly higher in progressors than in non-progressors (55±19 mg/dl vs. 37±18 mg/dl, P<0.01). On multiple logistic regression analysis, MAGE was an independent predictor of RP (odds ratio, 1.06 per 1 mg/dl; P<0.01). CONCLUSIONS MAGE early after the onset of ACS is a predictor of RP of non-culprit lesions.

Inhibition of DPP-4 by alogliptin improves coronary flow reserve and left ventricular systolic function evaluated by phase contrast cine magnetic resonance imaging in patients with type 2 diabetes and coronary artery disease

BACKGROUND The present study determined whether dipeptidyl peptidase-4 (DPP-4) inhibition by alogliptin improves coronary flow reserve (CFR) and left ventricular election fraction (LVEF) in patients with type 2 DM and CAD. MATERIALS AND METHODS Twenty patients with type 2 DM and known or suspected CAD were randomly allocated to receive diet therapy plus alogliptin (n=10; mean age, 73.3±6.6y) or a control group given diet therapy and glimepiride (n=10; mean age, 76.7±7.3y). Breath-hold PC cine MR images of the coronary sinus (CS) were acquired using a 1.5T MR scanner and 32 channel cardiac coils to assess blood flow of the CS at rest and during adenosine triphosphate (ATP) infusion. The CFR was calculated as CS blood flow during ATP infusion divided by that at rest. The CFR and LVEF were evaluated by MRI at baseline and at three months after starting therapy. RESULTS Hemoglobin A1c (HbA1c) was significantly reduced in both groups (alogliptin, 7.2±0.6% to 6.6±0.5%, p=0.034; control, 6.9±0.4% to 6.4±0.3%, p=0.008). However, CFR and LVEF significantly improved only in the alogliptin group (alogliptin: CFR, 2.15±0.61 to 2.85±0.80, p=0.042; LVEF, 59.4±6.3% to 68.0±8.6%, p=0.03; control: CFR, 2.17±0.37 to 2.38±0.32, p=0.19; LVEF, 58.2±9.1 to 60.3±8.8%, p=0.61). The % increases in CFR and in LVEF positively correlated (R=0.47 by Spearmans correlation coefficient; p=0.036). CONCLUSION The inhibition of DPP-4 by alogliptin improved CFR and LVEF evaluated by MRI in patients with type 2 DM and CAD and the improvement in CFR was associated with increased LV systolic function.

Higher CHADS2 score is associated with impaired coronary flow reserve: A study using phase contrast cine magnetic resonance imaging

BACKGROUND The presence of coronary microvascular dysfunction (CMD) is an important prognostic marker for coronary artery disease (CAD) patients. The purpose of this study was to investigate whether the CHADS2 score is associated with CMD evaluated by magnetic resonance imaging (MRI). MATERIALS AND METHODS One hundred forty three patients with known or suspected CAD (mean age 70.3±9.5years) were enrolled. All patients did not have any significant coronary stenosis on X-ray coronary angiography (CAG) at the time of MRI acquisition. By using a 1.5T MRI scanner, breath-hold phase contrast cine MRI images of coronary sinus (CS) were obtained to assess the blood flow of CS both at rest and during adenosine triphosphate (ATP) infusion. Coronary flow reserve (CFR) was calculated as CS blood flow during ATP infusion divided by CS blood flow at rest. CMD was defined as CFR<2.5 according to a previous study. Patients were allocated to four groups based on the CHADS2 score (group1: CHADS2 score=0, group2: CHADS2 score=1; group3: CHADS2 score=2, and group4: CHADS2 score≥3). RESULTS Mean CFR was 2.81±0.95 (77.6±32.7mL/min at rest; 208.2±86.5mL/min during ATP infusion, p<0.001). Patients with higher CHAD2 score had lower CFR. In the multiple logistic regression analysis, CHADS2 score was independently associated with CFR (odds ratio=0.61, 95% confidence interval: 0.37-0.99, p=0.049). CONCLUSIONS Higher CHADS2 score was significantly associated with lower CFR evaluated by phase contrast cine MRI.

Prediction of functional recovery after percutaneous coronary revascularization for chronic total occlusion using late gadolinium enhanced magnetic resonance imaging

BACKGROUND Limited data are available regarding the prediction for functional recovery using late gadolinium enhanced magnetic resonance imaging (LGE MRI) after coronary revascularization for chronic total occlusion (CTO PCI). METHODS We studied 59 patients (mean age, 66±11 years) who underwent successful CTO PCI. Two-dimensional echocardiography and strain measurements were performed before and 8±2 months after CTO PCI. The findings of segmental assessment were compared with the extent of LGE MRI using a 16-segment model. RESULTS From baseline to follow-up, ejection fraction (54.2±12.1% to 56.1±10.6%, p=0.010), global longitudinal strain (LS) (-15.1±5.1 to -16.7±5.1, p<0.001), global circumferential strain (CS) (-14.0±4.9 to -15.9±4.9, p<0.001), and wall motion score (WMS) index (1.45±0.53 to 1.33±0.39, p=0.014) significantly improved. In the territory of the CTO vessel, LS and CS significantly improved in segments of LGE ≤50%, but not in segments of LGE >50%. However, WMS improved only in segments of LGE 1-25%. At baseline and at follow-up, CS allowed better discrimination of segments of LGE >50% than WMS [at baseline; area under the curve (AUC) 0.79 vs. 0.68, respectively, p=0.001: at follow-up; AUC 0.84 vs. 0.69, respectively, p<0.001). Discriminatory ability of LS for segments of LGE >50% significantly improved from baseline to follow-up (AUC 0.73 vs. 0.83, p<0.001). CONCLUSIONS The cut-off value of the extent of LGE MRI is 50% to detect segments that will functionally recover after CTO PCI. Change in LS was more sensitive for removal of ischemia by CTO PCI, indicating the utility of LS to monitor the therapeutic effects of CTO recanalization.

IMPACT OF MYOCARDIAL EXTRACELLULAR VOLUME ASSESSED BY CARDIAC MAGNETIC RESONANCE T1 MAPPING ON SYSTOLIC AND DIASTOLIC FUNCTION OF THE HEART

Extracellular volume (ECV) derived cardiac magnetic resonance (CMR) T1-mapping has emerged as a non-invasive method to quantify extracellular matrix of human heart. The aim of this study was to assess the impact of ECV assessed by CMR T1 mapping on systolic and diastolic function of the heart

Distinction Between Precapillary and Postcapillary Pulmonary Hypertension by the Atrial Volume Ratio on Transthoracic Echocardiography

The differential diagnosis between precapillary and postcapillary pulmonary hypertension (PH) is important for deciding on the appropriate therapeutic strategy. The aim of this study was to assess whether the atrial volume ratio can differentiate precapillary and post‐capillary PH.

Impact of Hemodialysis on Procedural Outcomes of Percutaneous Coronary Intervention for Chronic Total Occlusion: Insights From the Japanese Multicenter Registry

Background Among patients treated with percutaneous coronary intervention for chronic total occlusion (CTO‐PCI), patients on long‐term hemodialysis are at significantly high risk for cardiovascular mortality and morbidity. However, clinical or angiographic predictors that might aid in better patient selection remain unclear. We aimed to assess the acute impact of hemodialysis in patients who underwent CTO‐PCI. Methods and Results The Retrograde Summit registry is a multicenter, prospective registry of patients undergoing CTO‐PCI at 65 Japanese centers. Patient characteristics and procedural outcomes of 4749 patients were analyzed, according to the presence (n=313) or absence (n=4436) of baseline hemodialysis. A prediction model for technical failure among hemodialysis patients was also developed. The technical success rate of CTO‐PCI was significantly lower in hemodialysis than in nonhemodialysis patients (78.0% versus 89.1%, P<0.001). The rates of in‐hospital major adverse cardiac and cerebrovascular events were similar between the 2 groups (1.6% versus 0.9%, P=0.24). Irrespective of clinical/angiographic characteristics or previously developed scoring systems, hemodialysis independently predicted technical failure for CTO‐PCI. Among hemodialysis patients, predictors of technical failure were blunt stump (odds ratio 2.45, 95% confidence interval, 1.15–5.21, P=0.021), severe lesion calcification (odds ratio 2.50, 95% confidence interval, 1.19–5.24, P=0.015), and absence of diabetes mellitus (odds ratio 3.15, 95% confidence interval, 1.49–6.64, P=0.003). In hemodialysis patients without these predictors, the technical success rate was 96.2%. Conclusions Hemodialysis is significantly associated with technical failure. Contemporary CTO‐PCI seems feasible and safe in selected hemodialysis patients.