Keitaro Mahara

Evaluation of automated measurement of left ventricular volume by novel real-time 3-dimensional echocardiographic system: Validation with cardiac magnetic resonance imaging and 2-dimensional echocardiography

BACKGROUND Traditional 3-dimensional echocardiography (3DE) with volumetric scanning technique requires several heart cycles for full-volume acquisition and complicated manual contouring of left ventricular (LV) endocardium. The new real-time 3DE (RT3DE) system allows acquisition of an instantaneous full-volume dataset in a single heart cycle and automated measurement of LV volume by the algorithm software. However, it has not been evaluated adequately whether automated measurement by RT3DE has better agreement with cardiac magnetic resonance imaging (CMR) than 2-dimensional echocardiography (2DE) with CMR. PURPOSE This study aimed to evaluate the accuracy of automated measurement of LV volume using RT3DE compared with 2DE and CMR. METHODS AND RESULTS Forty-four consecutive patients who underwent RT3DE, 2DE, and CMR were evaluated in this study. The feasibility of automated measurement by RT3DE was 93.2% and the mean operation time was 6min. LV volume and ejection fraction (EF) from semi-automated measurement [end-diastolic volume: r=0.96, limits of agreement (LOA) -30.5 to 39.3 ml; end-systolic volume: r=0.97, LOA -22.6 to 32.7 ml; EF: r=0.90, LOA -16.1 to 14.2%, respectively] had better agreement with CMR than those from 2DE (r=0.87, LOA -50.5 to 72.2 ml; r=0.93, LOA -34.1 to 65.2 ml; r=0.89, LOA -20.9 to 10.0%, respectively). CONCLUSION Semi-automated measurement by RT3DE has better agreement with CMR than 2DE in LV volume and EF. In addition, it is simple to operate and acceptable in feasibility for the clinical setting although there may be room for further learning required to incorporate small hypertrophic LV into the automated algorithm software.

Acute hyperglycaemia prevents the protective effect of pre-infarction angina on microvascular function after primary angioplasty for acute myocardial infarction

Background: Acute hyperglycaemia has been associated with impaired microvascular function after acute myocardial infarction (AMI), whereas pre-infarction angina (PIA) occurring shortly before the onset of AMI has been shown to reduce microvascular injury after reperfusion. Objective: To examine whether acute hyperglycaemia prevents the protective effect of PIA on microvascular function after AMI. Methods: We studied 205 patients with a first anterior wall AMI who underwent primary angioplasty within 12 hours of onset. Coronary flow velocity parameters were assessed immediately after reperfusion using a Doppler guidewire. Severe microvascular injury was defined as the presence of systolic flow reversal and diastolic deceleration time <600 ms. Echocardiographic wall motion was analysed before revascularisation and 4 weeks later. Results: Acute hyperglycaemia, defined as a blood glucose level of ⩾198 mg/dl on admission, was found in 67 (33%) patients. In patients without acute hyperglycaemia, PIA was associated with a lower incidence of systolic flow reversal, a longer diastolic deceleration time and a higher coronary flow reserve. However, in patients with acute hyperglycaemia there was no significant difference in these same parameters between patients with and without PIA. In the presence of acute hyperglycaemia PIA did not improve the change in wall motion score. In a multivariate model, the absence of PIA was an independent determinant of severe microvascular injury in patients without acute hyperglycaemia (odds ratio 6.28, p = 0.001), but not in patients with acute hyperglycaemia. Conclusion: The protective effect of PIA on microvascular function was attenuated in patients with acute hyperglycaemia, resulting in unfavourable functional recovery.

Impact of Acute Kidney Injury on Early to Long-Term Outcomes in Patients Who Underwent Surgery for Type A Acute Aortic Dissection.

Acute kidney injury (AKI) is relatively common after cardiothoracic surgery for type A acute aortic dissection (TA-AAD) and increases mortality. We investigated the incidence and risk factors for AKI in patients with TA-AAD and its impact on their outcomes. The records of 375 consecutive patients who underwent surgical treatment for TA-AAD from October 2007 to March 2013 were analyzed retrospectively. We defined AKI using the Kidney Disease Improving Global Outcomes criteria, which are based on serum creatinine concentration or glomerular filtration rate. We used Kaplan-Meier methods and multivariate Cox proportional hazards regression to assess the impact of AKI on both mortality and major adverse cardiovascular and cerebrovascular events. We also examined the association between risk factors and AKI using logistic regression modeling. Postoperative AKI was observed in 165 patients (44.0%). The overall 30-day and mid- to long-term mortality was 1.6% and 8.8%, respectively. Mortality and major adverse cardiovascular and cerebrovascular events correlated significantly with the severity of AKI, and multivariate analysis showed that AKI stage 3 (the most sever stage) was an independent risk factor for mortality (hazard ratio 6.83, 95% confidence interval 2.52 to 18.52) after adjustment for important confounding factors. Extracorporeal circulation time, body mass index, perioperative peak serum C-reactive protein concentration, renal malperfusion, and perioperative sepsis were found to be risk factors for AKI. In conclusion, AKI was common in patients who underwent surgery for type A acute aortic dissection. The severity of AKI strongly influences patient outcomes, so it should be recognized promptly and treated aggressively when possible.

Three-Dimensional Transesophageal Echocardiographic Evaluation of Coronary Involvement in Patients with Acute Type A Aortic Dissection

BACKGROUND Acute Stanford type A aortic dissection (AAD) with coronary involvement is associated with high mortality. However, coronary involvement is not always successfully visualized by computed tomography and two-dimensional (2D) transesophageal echocardiography (TEE). The aim of this study was to test the hypothesis that three-dimensional (3D) TEE can detect coronary involvement in patients with AAD. METHODS Fifty-one consecutive patients with AAD who underwent intraoperative TEE using an iE33 system during emergency surgery were enrolled. Using computed tomographic images, conventional 2D transesophageal echocardiographic images, and a 3D transesophageal echocardiographic data set, the status of coronary ostia was evaluated and classified into four types-branching from true lumen, branching from false lumen, dissection, and unclear-and these results were compared with operative findings. RESULTS In six patients, coronary involvement was diagnosed operatively by surgeons. They comprised dissection at three left coronary ostia and branching from false lumen at three right coronary ostia. All six cases were successfully detected by both 2D TEE and 3D TEE before instituting cardiopulmonary bypass. However, in 45 patients (90 ostia) confirmed operatively as having no coronary involvement, 69 ostia by computed tomography (36 in the left and 33 in the right coronary artery) and 16 ostia by 2D TEE (four in the left and 12 in the right coronary artery) were evaluated as unclear coronary involvement. On the other hand, 3D TEE clearly depicted no coronary involvement in all but one (right coronary ostium) of the unclear cases. CONCLUSIONS Three-dimensional TEE reduced the number of cases evaluated as unclear coronary involvement by computed tomography and 2D TEE. In patients with AAD, 3D TEE allows evaluation of the status of coronary ostia in the operating room.

The potential benefits and risks of the use of dual antiplatelet therapy beyond 6 months following sirolimus-eluting stent implantation for low-risk patients

BACKGROUND The optimal duration of dual antiplatelet therapy (DAT) in patients undergoing intracoronary sirolimus-eluting stent implantation remains controversial. OBJECTIVE To evaluate the clinical effects of long duration DAT in patients undergoing intracoronary sirolimus-eluting stent implantation in daily practice. In addition, to attempt to identify the optimal duration of DAT after implantation of a sirolimus-eluting stent. METHODS We retrospectively report on 1293 consecutive patients who underwent successful intracoronary sirolimus-eluting stent implantation. We analyzed the cumulative incidence of stent thrombosis, non-fatal myocardial infarction (MI), death from cardiac causes, and the cumulative incidence of bleeding complications. RESULTS We compared the study end point in patients who received DAT for <6 months (n=1136) with that for patients who received DAT for >6 months (n=157). The median follow-up period was 1260 ± 462 days. Major bleeding occurred in 35 patients and intracranial hemorrhage in 8. In patients on DAT for >6 months, the incidence of any bleedings, major bleedings, and intracranial hemorrhage was significantly increased. On the other hand, there was no significant difference between the two groups in the risk of the primary end points (stent thrombosis, non-fatal MI, death from cardiac causes, death or MI). CONCLUSIONS Prolonged DAT for more than 6 months was not significantly more beneficial than aspirin monotherapy in reducing the risk of the occurrence of acute MI, stent thrombosis, and death, although it was associated with an increase in bleeding complications for low-risk patients.

Validation of the Get With The Guideline–Heart Failure risk score in Japanese patients and the potential improvement of its discrimination ability by the inclusion of B-type natriuretic peptide level

BACKGROUND Detailed characteristics of patients with acute heart failure (AHF) in Japan have not been elucidated. Furthermore, international application of risk models obtained in the United States has not been validated. METHODS We evaluated the Get With The Guidelines-Heart Failure (GWTG-HF) risk score performance in AHF patients enrolled in the West Tokyo Heart Failure registry, a large, ongoing, prospective, multicenter cohort registry. Variables required for the GWTG-HF risk score were race, age, systolic blood pressure, heart rate, blood urea nitrogen level, sodium concentration, and presence of chronic obstructive pulmonary disease. Score discrimination and calibration were evaluated by the c statistic, Hosmer-Lemeshow statistic, and visual plotting. We conducted additional analyses to determine whether other variables improved the performance of the score. The primary outcome was in-hospital mortality. RESULTS In total, 1,876 patients were admitted for AHF between April 2006 and August 2014. The patients were predominantly men (60.6%), with a mean age of 73.3 ± 13.6 years. Sixty-eight (3.6%) patients died during hospitalization. The GWTG-HF risk score showed acceptable discrimination; the c statistic for in-hospital mortality in this cohort was 0.763 (95% CI, 0.700-0.826). The calibration plot showed good conformance between the predicted and observed in-hospital mortality. Notably, addition of B-type natriuretic peptide level to the conventional GWTG-HF score significantly improved the discrimination (c statistic, 0.818; 95% CI, 0.771-0.865). CONCLUSIONS The GWTG-HF risk score can be applied in Japanese AHF patients with good discrimination and calibration. Furthermore, addition of B-type natriuretic peptide level improves discrimination and could be considered in future risk models.

Waist circumference reduction is more strongly correlated with the improvement in endothelial function after acute coronary syndrome than body mass index reduction

BACKGROUND Endothelial function predicts recurrence of adverse cardiac events in patients with acute coronary syndromes (ACS). Moreover, the recovery of endothelial function correlates with cardiac event-free survival. OBJECTIVES The aim of this study was to determine which clinical factors correlate with the improvement in endothelial function after ACS. METHODS Vascular endothelial function was assessed in 98 patients with ACS by flow-mediated dilation (FMD) of the brachial artery using high-resolution ultrasound at 2 weeks and 6 months after ACS. We measured several risk parameters including plasma markers of glucose homeostasis, lipids, and blood pressure at baseline and at 6 months after ACS. Body mass index (BMI) and waist circumference (WC) were also measured as anthropometric assessments. RESULTS At baseline, FMD was significantly correlated with BMI, WC, high-density lipoprotein cholesterol, the homeostasis model assessment of insulin resistance, and brachial artery diameter (r=-0.32, p=0.001; r=-0.44, p<0.0001; r=0.34, p=0.0006; r=-0.21, p=0.04; r=-0.47, p<0.0001, respectively). In a stepwise multivariate regression analysis at baseline, larger WC and brachial artery diameter were independently correlated with lower brachial artery FMD (R(2)=0.319, p<0.0001). At 6 months, the change in FMD was significantly correlated with the change in WC and BMI (r=-0.59, p<0.0001; r=-0.33, p=0.001, respectively). In a stepwise multivariate regression analysis, WC reduction was independently correlated with improved FMD (R(2)=0.349, p<0.0001). CONCLUSIONS WC reduction is more strongly correlated with the improvement of endothelial function after ACS than BMI reduction.

Impact of regurgitant orifice height for mechanism of aortic regurgitation.

A classification of aortic regurgitation (AR) by transesophageal echocardiography (TEE) has been considered a critical pre-operative assessment, particularly for valve repair operations [(1)][1]. This study aimed to evaluate the mechanism of isolated AR by quantitative analysis of aortic valve

Aging Adversely Affects Postinfarction Inflammatory Response and Early Left Ventricular Remodeling after Reperfused Acute Anterior Myocardial Infarction

Background and Aims: We have demonstrated that an increased peak serum C-reactive protein (CRP) level after acute myocardial infarction (AMI) was a major predictor of left ventricular (LV) remodeling. We sought to clarify the effect of aging on the postinfarction inflammatory response and LV remodeling. Methods: We studied 102 patients who underwent primary angioplasty for a first anterior Q-wave AMI. Serum CRP levels, plasma neurohormones and interleukin-6 (IL-6) levels, and LV volume by left ventriculography were serially measured. Patients were divided into two groups according to their age (≧70 years, n = 33; <70 years, n = 69). Results: There was no difference in use of cardiovascular drugs and coronary angiographic findings. Older patients had a greater increase in LV end-diastolic volume during 2 weeks after AMI (p = 0.0007) and a higher peak CRP level (12.4 ± 7.3 vs. 5.5 ± 4.2 mg/dl, p < 0.0001), although peak CK level was comparable between the two groups. Plasma atrial natriuretic peptide, brain natriuretic peptide and IL-6 levels were higher in older patients at 2 weeks and 6 months after AMI. Conclusions: Augmented and prolonged activation of the inflammatory system after AMI was observed in older patients, in association with exaggerated LV remodeling. Aging may adversely affect LV remodeling through modification of the inflammatory response after AMI.

The impact of gender difference on the effects of preinfarction angina on microvascular damage with reperfused myocardial infarction.

Few studies have addressed gender differences in evoking preconditioning. In an experimental study, it was reported that the preconditioning effect disappeared after gonadectomy.