Impact of right coronary artery dominance on the long-term mortality in the patients with acute total/subtotal occlusion of unprotected left main coronary artery.

BACKGROUND: Patients with a right dominant coronary artery anatomy account for a significant proportion of acute myocardial infarction cases, and this condition is associated with a better prognosis. However, there are limited data on the impact of coronary dominance on patients with acute total/subtotal occlusion of unprotected left main coronary artery (ULMCA). METHODS: This study aimed to assess the impact of right coronary artery (RCA) dominance on long-term mortality in patients with acute total/subtotal occlusion of the ULMCA. From a multicenter registry, 132 cases of consecutive patients who had undergone emergent percutaneous coronary intervention (PCI) due to acute total/subtotal occlusion of the ULMCA were reviewed. RESULTS: Patients were classified into two groups according to the size of their RCA (dominant RCA group, n = 29; non-dominant RCA group, n = 103). Long-term outcomes were examined according to the presence of dominant RCA. Cardiopulmonary arrest (CPA) occurred in 52.3 % of patients before revascularization. All-cause death was significantly lower in the dominant RCA group than in the non-dominant RCA group. In the Cox regression model, dominant RCA was an independent predictor of all-cause death, as well as total occlusion of ULMCA, collateral from RCA, chronic kidney disease, and CPA. Patients were further analyzed according to the degree of stenosis of the ULMCA; patients with non-dominant RCA and total occlusive ULMCA had the worst outcome compared with the other groups. CONCLUSIONS: A dominant RCA might improve long-term mortality in patients with acute total/subtotal occlusion of the ULMCA who were treated with PCI.

Long-term outcomes of percutaneous revascularization for internal mammary artery-left anterior descending artery bypass failure.

Despite the excellent long-term results of internal mammary artery (IMA)-left anterior descending (LAD) bypass, percutaneous revascularization of IMA is sometimes required for IMA-LAD bypass failure. However, its clinical outcomes have not been fully elucidated. The aim of this study was to investigate the long-term clinical outcomes, including target lesion revascularization (TLR) following contemporary percutaneous revascularization of failed IMA bypass graft. We examined data of 59 patients who had undergone percutaneous revascularization of IMA due to IMA-LAD bypass failure at nine hospitals. Patients with IMA graft used for Y-composite graft or sequential bypass graft were excluded. The incidence of TLR was primarily examined, whereas other clinical outcomes including cardiac death, myocardial infarction, and target vessel revascularization were also evaluated. Mean age of the enrolled patients was 67.4 ± 11.3 years, and 74.6% were men. Forty patients (67.8%) had anastomotic lesions, and 17 (28.8%) underwent revascularization within three months after bypass surgery. Procedural success was achieved in 55 (93.2%) patients. Stent implantation was performed in 13 patients (22.0%). During a median follow-up of 1401 days (interquartile range, 282-2521 days), TLR was required in six patients (8.5% at 1, 3, and 5 years). Patients who underwent percutaneous revascularization within 3 months after surgery tended to have a higher incidence of TLR. Clinical outcomes of IMA revascularization for IMA-LAD bypass failure were acceptable.

Relationship between tissue characteristics and mechanical properties of coronary plaques: a comparison between integrated backscatter intravascular ultrasound (IVUS) and speckle-tracking IVUS.

High-risk coronary plaques have certain morphological characteristics. Thus, comprehensive assessment is needed for the risk stratification of plaques in patients with coronary artery disease. Integrated backscatter intravascular ultrasound (IB-IVUS) has been used successfully used to evaluate the tissue characteristics of coronary plaques; however, the mechanical properties of plaques have been rarely assessed. Therefore, we developed Speckle-tracking IVUS (ST-IVUS) to evaluate the mechanical properties of coronary plaque. This study aimed to evaluate the relation between the tissue characteristics of coronary plaques using IB-IVUS and their mechanical properties using ST-IVUS. We evaluated 95 non-targeted plaques in 95 patients undergoing elective percutaneous coronary intervention to the left anterior descending artery. We set regions of interest (ROIs) in the cross-sectional images of coronary plaques where we divided 120 degree plaques into four quadrants (every 30 degrees), with the center at the area of maximum atheroma thickness. We measured relative calcification area (%CA, relative fibrous area (%FI) and relative lipid pool area (%LP) in a total of 380 ROIs. In ST-IVUS analysis, we measured strain in the circumferential direction of the lumen area (LA strain: %), the external elastic membrane area strain (EEM strain: %), and strain in the radial direction (radial strain: %). On global cross-sectional area IB-IVUS analysis, the %CA was 1.2 ± 1.2%; the %FI was 49.0 ± 15.9%, and the %LP was 49.7 ± 16.5%. In ST-IVUS analysis, the LA strain was 0.67 ± 0.43%; the EEM strain was 0.49 ± 0.33%, and the radial strain was 2.02 ± 1.66%. On regional analysis, the %LP was not associated with the LA strain (r = - 0.002 p = 0.97), the EEM strain (r = - 0.05 p = 0.35), or with the radial strain (r = - 0.04 p = 0.45). These trends were seen between the %FI and the LA strain (r = 0.02 p = 0.74), the %FI and the EEM strain (r = 0.05 p = 0.35), and the %FI and the radial strain (r = 0.04 p = 0.50). A significant correlation was only observed between the %CA and the LA strain (r = - 0.15 p = 0.0038). Our findings indicate that the associations between mechanical properties and tissue characteristics lacked statistical significance, more often than not, and that it is necessary to evaluate the mechanical properties as well as plaque characteristics for risk stratification of coronary plaques.

Observation of plaque behavior and tissue characterization of coronary plaque using speckle tracking intravascular ultrasound (ST-IVUS) and iMap imaging system.

Tissue characterization plays an important role in the development of acute coronary syndromes. iMap is an intravascular ultrasound (IVUS) tissue characterization system that provides useful information by reconstructing color-coded maps. Mechanical properties due to dynamic mechanical stress during a cardiac cycle may also trigger vulnerable plaque. Speckle tracking IVUS (ST-IVUS) has been introduced to observe plaque behavior in relation to mechanical properties. We report the case of an 84-year-old woman with stable coronary artery disease who underwent percutaneous coronary intervention, at which time IVUS demonstrated mainly three low echoic areas like lipid pools with thick fibrous caps. Pathological evaluation with iMap revealed that one low echoic area was occupied with necrotic tissue and that the other two areas occupied fibrotic. Although those tissue characterizations were different, they showed similar stretching behavior at systole by ST-IVUS which depicted plaque behavior from IVUS images using a color mapping. The mechanical properties of individual coronary plaques may differ depending on the tissue disposition. It is necessary to consider mechanical properties using ST-IVUS as well as to evaluate tissue characterization in plaque risk stratification.

Level 3 tracheal injury in acute coronary syndrome treated conservatively with extracorporeal membrane oxygenation.

Level 3 tracheal injury, characterised by complete laceration with oesophageal or mediastinal soft-tissue herniation, is conventionally indicated for surgical repair. We present the case of a woman in her 60s with level 3 tracheal injury in acute coronary syndrome who was treated successfully without surgery. Venoarterial extracorporeal membrane oxygenation (ECMO) was introduced during lung-rest management to avoid positive pressure ventilation, and percutaneous coronary angioplasty was performed. Venoarterial ECMO was switched to venovenous ECMO when the haemodynamics improved. The tracheal injury healed spontaneously in 10 days, and ECMO was withdrawn on day 15. The patient made full recovery and was discharged on day 51.

Impact of accelerated washout of Technetium-99m-sestamibi on exercise tolerance in patients with acute coronary syndrome: single-center experience.

Technetium-99m-sestamibi (99mTc-sestamibi) single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in patients with acute coronary syndrome (ACS) could be used to assess area-at-risks, as well as myocardial infarct or saved sizes. In patients with ACS, accelerated washout of 99mTc-sestamibi during early and delayed imaging in the acute phase may suggest mitochondrial dysfunction in the injured but salvaged myocardium. However, the link between 99mTc-sestamibi accelerated washout and exercise tolerance is unknown. The purpose of this study was to investigate a possible association between 99mTc-sestamibi accelerated washout and exercise tolerance in acute ACS patients as they progressed into the chronic phase. One hundred and sixty-five patients with ACS who underwent 99mTc-sestamibi SPECT MPI during the acute phase were recruited. On this basis, we calculated the total perfusion deficits (TPDs) for early (1 h after tracer injection) and delayed (4 h after tracer injection) images using automated quantification software. We then subtracted the early TPDs from the delayed TPDs to calculate the ΔTPD. We conducted a cardiopulmonary exercise test in acute and chronic phases. We divided two groups according to the median ΔTPD (the ΔTPD ≥ 4 group and the ΔTPD < 4 group) and compared anaerobic threshold (AT; ml/kg/min) between the groups. For anaerobic threshold (AT) improvement in data analysis, we employed multivariate logistic regression analysis. A total of 101 ST-segment elevation myocardial infarctions, 36 non-ST-elevation myocardial infarctions, and 28 unstable angina pectoris events were reported as ACS. From acute phase (10.8 ± 4.2 ml/kg/min) to chronic phase (11.9 ± 2.3 ml/kg/min), the AT in the ΔTPD ≥ 4 group was significantly increased (p < 0.0001). This trend was also seen in the ΔTPD < 4 group from acute (11.4 ± 1.8 ml/kg/min) to chronic phase (12.1 ± 2.2 ml/kg/min, p = 0.015). AT was lower in the ΔTPD ≥ 4 group in the acute phase (p = 0.027), but there was no difference in AT between the two groups in the chronic phase (p = 0.60). ΔTPD and the absence of diabetes were both independent predictors of AT improvement in multivariate logistic regression analysis. Receiver-operating characteristic curve analysis determined that ΔTPD = 6 was the best cut-off value, with 60.0% sensitivity and 71.4% specificity, respectively. The accelerated washout of 99mTc-sestamibi in patients with ACS during the acute phase could help to predict improvement in exercise tolerance in the chronic phase.

＜Editors' Choice＞ Prevalence of acute coronary syndrome during the pandemic of COVID-19 in the Tokai Region of Japan.

The outbreak of coronavirus disease 19 (COVID-19) has had a great impact on medical care. During the COVID-19 pandemic, the rate of hospital admissions has been lower and the rate of in-hospital mortality has been higher in patients with acute coronary syndrome (ACS) in Western countries. However, in Japan, it is unknown whether the COVID-19 pandemic has affected the incidence of ACS. In the study, eleven hospitals in the Tokai region participated. Among enrolled hospital, we compared the incidence of ACS during the COVID-19 pandemic (April and May, 2020) with that in equivalent months in the preceding year as the control. During the study period; April and May 2020, 248 patients with ACS were admitted. Compared to April and May 2019, a decline of 8.1% [95% confidence interval (CI) 5.2-12.1; P = 0.33] in admissions for ACS was observed between April and May 2020. There was no significant difference in the strategy for revascularization and in-hospital deaths between 2019 and 2020. In conclusion, the rate of admission for ACS slightly decreased during the COVID-19 pandemic, compared to the same months in the preceding year. Moreover, degeneration of therapeutic procedures for ACS did not occur.

Clinical Outcomes Following Emergent Percutaneous Coronary Intervention for Acute Total/Subtotal Occlusion of the Left Main Coronary Artery.

BACKGROUND: Data regarding the clinical features, outcomes and prognostic factors in patients presenting with acute total/subtotal occlusion of the unprotected left main coronary artery (LMCA) remain limited.Methods and Results:From a multi-center registry, 134 patients due to acute total/subtotal occlusion of the unprotected LMCA were reviewed. Emergency room (ER) status classification was defined according to the presence of cardiogenic shock and cardiopulmonary arrest (CPA) in the ER (class 1=no cardiogenic shock; class 2= cardiogenic shock but not CPA; and class 3=CPA). In-hospital mortality and cerebral performance category (CPC) as the endpoints were evaluated. One-half (67/134) of the enrolled patients presented with total occlusion of the unprotected LMCA. Regarding ER status classification, class 1, 2, and 3 were observed in 30.6%, 45.5%, and 23.9% of the patients, respectively. In-hospital mortality occurred in 73 (54.5%) patients; of the remaining patients, 52 (85.3%) could be discharged with a CPC 1 or 2. ER status classification (odds ratio 4.4 [95% confidence interval: 2.33-10.67]; P<0.001) and total occlusion of the unprotected LMCA (odds ratio 8.29 [95% confidence interval 2.93-23.46]; P<0.001) were strong predictors of in-hospital mortality. CONCLUSIONS: Acute total/subtotal occlusion involving the unprotected LMCA appeared to be associated with high in-hospital mortality. ER status classification and initial flow in the unprotected LMCA were significant predictive factors of in-hospital mortality.

Assessment of visit-to-visit variability in systolic blood pressure over 5 years and phasic left atrial function by two-dimensional speckle-tracking echocardiography.

Visit-to-visit variability in systolic blood pressure (VVV-SBP) has been associated with increased cardiac events. Hence, volume analysis by two-dimensional speckle-tracking echocardiography (2-DSTE) allows physicians to easily measure phasic left atrial (LA) function. However, the relationship of VVV-SBP and functional deformation of the left atrium with patients' clinical outcome is unclear. The aim of the study was to investigate the relationship between phasic LA function and VVV-SBP. The subjects were 70 male participants in whom 2-DSTE was performed to measure blood pressure at health check-ups every year for 5 years. The standard deviation of systolic blood pressure (SBP) was calculated to assess VVV-SBP. The average SBP (Ave-SBP) was also assessed. Total emptying function (EF) (reservoir function), passive EF (conduit function), and active EF (booster pump function) of the left atrium were calculated to evaluate phasic LA function by 2-DSTE. The Pearson correlation, simple regression analysis, and multivariate logistic regression analysis were used in data analysis. Participants' mean age was 50 ± 10 years, and 16 participants had hypertension. VVV-SBP correlated with total EF (r = - 0.30, p = 0.014) and active EF (r = - 0.35, p = 0.003). There was no correlation between the standard deviation of SBP and passive EF (r = - 0.10, p = 0.39). Ave-SBP had no significant relationship with total EF (r = - 0.06, p = 0.62), passive EF (r = - 0.08, p = 0.50), or active EF (r = - 0.03, p = 0.78). Active EF was also associated with VVV-SBP in multiple regression analysis. The active EF was significantly decreased in the highest quartile of VVV-SBP. Despite the small sample size of our study, the VVV-SBP showed a relationship with the phasic LA function. Our findings suggest that high VVV-SBP is noted to be associated with cardiovascular risk including a deterioration of LA function in clinical practice.

Impact of neointimal tissue characterization and heterogeneity of bare-metal stents and drug-eluting stents on the time course after stent implantation evaluated by integrated backscatter intravascular ultrasound.

Pathological studies have suggested the different process of in-stent restenosis (ISR) of bare-metal stents (BMS) and drug-eluting stents (DES). Here, we evaluated the components of neointimal tissue using integrated backscatter intravascular ultrasound (IB-IVUS) and focused on the time course after stent implantation and tissue signal distribution. We evaluated 125 lesions of 125 patients who underwent target lesion revascularization for ISR (BMS: n = 73, DES: n = 52). Volume analysis of a 4-mm length centered on a minimum lumen area in every 1-mm cross-sectional area was performed. For IB-IVUS analysis, color-coded maps were constructed from the default setting based on the integrated backscatter (IB) values (middle-IB value, green: fibrous and low-IB value, blue: lipid pool). For the neointimal tissue volume, we evaluated the ratios of the green (%G) and blue (%B) areas. Tissue signal distribution (TD) was also obtained from the default setting based on IB values in each pixel of IB-IVUS imaging. We compared values of neointimal tissues measured by IB-IVUS between the DES and BMS and time course. The observed period was longer after BMS implantation than after DES implantation (BMS: 2545 days, DES: 1233 days, p < 0.001). Overall, %G and %B were similar between the BMS and DES groups (%G: 55% and 51%, respectively, p = 0.10; %B: 36% and 38%, respectively, p = 0.51); however, TD was significantly higher in the DES group than in the BMS group (1091 vs. 1367, p < 0.001). TD in the DES group remained high during the follow-up periods. However, TD in the BMS group was low in the early phase and significantly increased over time (r = 0.56, p < 0.001). When analyzing the ISR within 2 years after stent implantation, the BMS was distinguished with a sensitivity of 66% and a specificity of 90% (cut-off value: TD = 1135, area under the curve 0.83, 95% confidence interval 0.74-0.92). TD could differentiate neointimal tissue after BMS implantation in the early phase. TD can be a useful index in the observation of neoatherosclerosis.

Relationship between electrical conduction and phasic left atrial function: P-wave signal-averaged electrocardiography and time-left atrial volume curve assessments using two-dimensional speckle-tracking echocardiography.

P-wave signal-averaged electrocardiography (P-SAECG) can detect imperceptible conduction abnormalities, and volume analysis using two-dimensional speckle-tracking echocardiography (2-DSTE) allows us to easily measure the phasic function of the left atrium (LA). Both conduction abnormalities and functional deformation of the LA may be linked to the clinical outcome; however, the exact relationship is unclear. The aim of this study was to investigate the relationship between the phasic function of the LA and electrical conduction using P-SAECG and 2-DSTE. The subjects were 112 male volunteers (age 46.9 ± 13.2 years) with normal cardiac function who underwent P-SAECG and 2-DSTE. The filtered p-wave duration (FPD) and the root-mean-square voltage for the last 20 ms (RMS20) on P-SAECG wave were measured in ms and µV, respectively. Total emptying function (EF) (reservoir function), passive EF (conduit function), and active EF (booster pump function) of the LA were calculated as percentages to evaluate phasic LA function using 2DSTE. The mean FPD was 134.3 ± 11.7 ms and the mean RMS20 was 4.59 ± 2.39 µV. The mean total EF was 60.5 ± 13.1%, mean passive EF was 39.4 ± 13.9%, and mean active EF was 35.1 ± 13.9%. FPD had a negative correlation with passive EF (r = - 0.20, p = 0.039). FPD showed no significant relationship with total EF (r = - 0.03, p = 0.78) or active EF (r = 0.13, p = 0.18). There was a significant association between RMS20 and passive EF (r = 0.19, p = 0.048); however, no there was no correlation between RMS20 and total EF (r = 0.12, p = 0.23), or between RMS20 and passive EF (r = - 0.02, p = 0.86). In multivariate regression analysis, passive EF was an independent factor that influenced FPD duration. This study indicated that FPD was associated with conduit function, which includes phasic LA function. Therefore, electrical conduction of the LA and left ventricular diastolic function are closely related. In the clinical setting, when conduction abnormalities are detected, lifestyle measures or interventions can be applied to reduce cardiovascular risk.

Left Ventricular Torsion in Hypertension and Hypertensive Heart Failure　- 3-Dimensional Speckle Tracking Echocardiography Assessment.

Background: Left ventricular (LV) torsion by contraction of inner and outer oblique muscles contributes to EF. Outer muscle plays a predominant role in torsion. We evaluated the impact of LV remodeling by hypertension (HTN) on torsion using 3-dimensional speckle tracking echocardiography (3D-STE). Methods and Results: LV strain, strain rate during systole (SR-S) and torsion at endocardium, mid-wall and epicardium were assessed on 3D-STE in 53 controls and 186 HTN patients. Torsion was defined as the difference between apical and basal rotation divided by long axis length. LVEF and strain, SR-S and torsion in all 3 layers in HTN without LV hypertrophy (LVH) were similar to those in controls. LV longitudinal strain at endocardium in HTN with LVH decreased, whereas LVEF was similar to that in controls and, which was associated with increased torsion at epicardium. Reduced LVEF in hypertensive HF was associated with reduced strain, SR-S and torsion in all layers and with LV dilation. On multivariate analysis, epicardial torsion was an independent determinant of LVEF. At epicardial torsion cut-off 0.41, the sensitivity and specificity for the identification of HFrEF were 88% and 68%. Conclusions: Torsion on 3D-STE may represent a compensatory mechanism to maintain LVEF despite reduced endocardial function, suggesting that the deterioration of torsion caused by insult to outer muscle and dilation may lead to HFrEF.

Heparin-induced thrombocytopenia associated with polycythemia vera during the treatment of acute coronary syndrome.

Here, we report a case of heparin-induced thrombocytopenia (HIT) associated with polycythemia vera (PV) during the treatment of acute coronary syndrome. An 84-year-old woman with pre-existing PV had an acute myocardial infarction and developed HIT after using heparin. An additional myocardial infarction was caused by HIT, and caused marked damage to her cardiac function. However, she was successfully treated with argatroban infusion and intensive care. In this case, we suspected HIT at an extremely early stage, when the decline in platelet count remained at 16%, which might have prevented further thrombosis. Subsequently, the nadir in the platelet count remained at 32%, which resulted in "intermediate possibility of HIT" according to the 4Ts score; thus, further detailed serological examination may be required for accurate diagnosis of HIT. .

A novel ultrasound predictor of pulmonary capillary wedge pressure assessed by the combination of left atrial volume and function: A speckle tracking echocardiography study.

BACKGROUND: We hypothesized that a development of a novel index based on the combination of left atrial volume (LAV) and left atrial (LA) function evaluated by the time-LA volume curve using speckle tracking echocardiography (STE) would be accurate and useful to estimate pulmonary capillary wedge pressure (PCWP). Our goal was to develop a novel index of PCWP based on a combination of LAV and LA function using STE. METHODS: A cross-validation study was performed with the patients divided into a training study to define the novel index (n=50) and a testing study to validate the index (n=196). PCWP was measured by right heart catheterization, and phasic LAV and emptying function (EF) were measured by STE. RESULTS: Simple linear regression analysis in the training study revealed that the novel index that best estimated PCWP was the kinetics-tracking index [KT index=log10 (active LAEF/minimum LAV index)]. Multiple regression analysis revealed that the KT index was the most reliable predictor of PCWP. It had the strongest correlation with PCWP (r=-0.86, p<0.001) among all echocardiographic parameters. In the testing study, PCWP estimated by the KT index was also strongly correlated with measured PCWP (r=0.92, p<0.001). These correlations were also strong in the patients with reduced left ventricular ejection fraction (<50%), chronic heart failure, and chronic atrial fibrillation (r=0.92, r=0.91, r=0.79, p<0.001, respectively). CONCLUSIONS: A novel index (KT index) using a combination of LAV and LA function was a powerful and useful predictor of PCWP and may be valuable in routine clinical practice.

Impact of tissue characteristics on luminal narrowing of mild angiographic coronary stenosis: assessment of integrated backscatter intravascular ultrasound.

Integrated backscatter intravascular ultrasound (IB-IVUS) is a useful method for analyzing coronary plaque tissue. We evaluated whether tissue composition determined using IB-IVUS is associated with the progression of stenosis in coronary angiography. Sixty-three nontarget coronary lesions in 63 patients with stable angina were evaluated using conventional IVUS and IB-IVUS. IB-IVUS images were analyzed at 1-mm intervals for a length of 10 mm. After calculating the relative areas of the tissue components using the IB-IVUS system, fibrous volume (FV) and lipid volume (LV) were calculated through integration of the slices, after which percentages of per-plaque volume (%FV/PV, %LV/PV) and per-vessel volume (%FV/VV, %LV/VV) were calculated. Progression of coronary stenosis was interpreted from the increase in percent diameter stenosis (%DS) from baseline to the follow-up period (6-9 months) using quantitative coronary angiography. %DS was 24.1 ± 12.8 % at baseline and 23.2 ± 13.7 % at follow-up. Using IB-IVUS, LV was 31.7 ± 10.5 mm(3), and %LV/PV and %LV/VV were 45.6 ± 10.3 % and 20.2 ± 6.0 %, respectively. FV, %FV/PV, and %FV/VV were 35.5 ± 12.1 mm(3), 52.1 ± 9.5 %, and 23.4 ± 7.1 %, respectively. The change in %DS was -0.88 ± 7.25 % and correlated closely with %LV/VV (r = 0.27, P = 0.03) on simple regression. Multivariate regression after adjustment for potentially confounding risk factors showed %LV/VV to be correlated independently with changes in %DS (r = 0.42, P = 0.02). Logistic regression analysis after adjusting for confounding coronary risk factors showed LV (odds ratio 1.08; 95 % confidence interval 1.01-1.16; P = 0.03) and %LV/VV (odds ratio 1.13; 95 % confidence interval 1.01-1.28; P = 0.03) to be independent predictors of the progression of angiographic coronary stenosis. Our findings suggest that angiographic luminal narrowing of the coronary artery is likely associated with tissue characteristics. IB-IVUS may provide information about the natural progression of luminal narrowing in coronary stenosis.

Long-term changes in neointimal hyperplasia following implantation of bare metal stents assessed by integrated backscatter intravascular ultrasound.

In-stent restenosis (ISR) is a common phenomenon with bare metal stents (BMSs) in the early stage after implantation. However, ISR occurs at a lower rate with long time after BMS implantation. We assessed changes over time in neointimal hyperplasia following BMS implantation using integrated backscatter intravascular ultrasound (IB-IUVS). Thirty-six patients who received target lesion revascularization (TLR) to treat ISR were classified according to the duration of the interval between stent implantation and TLR: the early group (within first year n = 25) and the VL group (very late ISR ≥5 years, n = 11). IB-IUVS was used to evaluate within-stent sites from the proximal to the distal edge of the stent. IB-IVUS color maps were then constructed by tracing the stent struts and vessel lumen. Neointimal tissue was classified as high-IB (IB <-29 dB; a representative cord of calcification), middle-IB (-49 dB ≤ IB < -29 dB; fibrosis), or low-IB (-49 dB ≤ IB; lipid pool). We compared percent (%) volume, average %area of cross-sectional area (CSA), and %area of minimum CSA of each component between the groups. There were no significant differences in %volume, average %area of CSA, or %area of minimum CSA for the high-IB component between groups. The %low-IB components were 20.0 ± 8.8 % for volume, 20.1 ± 8.9 % for mean CSA, and 17.6 ± 8.5 % for minimum CSA in the early group. On the other hand, in the VL group, the %low-IB components were significantly increased to 31.8 ± 7.9 % for volume (p < 0.01 vs. the early group), 31.2 ± 7.6 % for mean CSA (p < 0.01 vs. the early group), and 33.1 ± 12.3 % for minimum CSA (p < 0.01 vs. the early group). By contrast, the %middle-IB component showed a reduction in extended time, with %volume of the middle-IB decreasing from 78.3 ± 8.1 to 66.4 ± 7.1 %, average mean %area of CSA from 78.2 ± 8.2 to 66.9 ± 6.9 %, and % area of minimum CSA from 80.7 ± 7.9 to 65.5 ± 11.4 % (p < 0.01;. the early vs. the VL group). Our results suggest that in-stent neointimal tissues developing over time consist of an increased low-IB component and a decreased middle-IB component and may contribute an increased of lipidemic component and a decreased of fibrotic component.

Motion of left atrial appendage as a determinant of thrombus formation in patients with a low CHADS2 score receiving warfarin for persistent nonvalvular atrial fibrillation.

BACKGROUND: The aim of this study was to define the independent determinants of left atrial appendage (LAA) thrombus among various echocardiographic parameters measured by Velocity Vector Imaging (VVI) in patients with nonvalvular atrial fibrillation (AF) receiving warfarin, particularly in patients with a low CHADS2 score. METHODS: LAA emptying fraction (EF) and LAA peak longitudinal strain were measured by VVI using transesophageal echocardiography in 260 consecutive patients with nonvalvular persistent AF receiving warfarin. The patients were divided into two groups according to the presence (n=43) or absence (n=217) of LAA thrombus. Moreover, the patients within each group were further divided into subgroups according to a CHADS2 score ≤1. RESULTS: Multivariate logistic regression analysis showed that LAAEF was an independent determinant of LAA thrombus in the subgroup of 140 with a low CHADS2 score. Receiver operating characteristics curve analysis showed that an LAAEF of 21% was the optimal cutoff value for predicting LAA thrombus. CONCLUSIONS: LAA thrombus formation depended on LAA contractility. AF patients with reduced LAA contractile fraction (LAAEF ≤21%) require strong anticoagulant therapy to avoid thromboembolic events regardless of a low CHADS2 score (≤1).

Effects of pitavastatin on cardiac structure and function and on prevention of atrial fibrillation in elderly hypertensive patients: a prospective study of 2-years' follow-up.

BACKGROUND: The aim of this prospective study was to determine whether statin therapy (pitavastatin) has a beneficial effect on the prevention of new-onset atrial fibrillation (AF) in elderly patients with hypertension (HTN) and to evaluate the relationships among statin treatment, the development of AF, and left atrial (LA) and ventricular (LV) structure and function. METHODS AND RESULTS: We enrolled eligible elderly patients (≥65 years old) with HTN and LV hypertrophy until the number of patients reached 110 in both groups. The 110 patients with HTN who needed statin therapy (HTN with statin group) were started on pitavastatin (1-2 mg/day), and both groups continued with appropriate medication for HTN. LV and LA structure and function were examined by conventional and speckle-tracking echocardiography at baseline and after 1 year. LA volume and function in the HTN with statin group improved more than in the HTN without statin group. There was a significant difference in survival free of new-onset AF in the patients with and without statin therapy during the 2-year follow-up (hazard ratio: 0.32, P=0.027). CONCLUSIONS: Pitavastatin had a beneficial effect on LV diastolic function and LA structure and function in elderly patients with HTN. Pitavastatin treatment may be associated with a lower incidence of new-onset AF.

Left atrial appendage emptying fraction assessed by a feature-tracking echocardiographic method is a determinant of thrombus in patients with nonvalvular atrial fibrillation.

BACKGROUND: Left atrial appendage (LAA) thrombus increases the risk of thromboembolism in atrial fibrillation (AF), and LAA contractile function like emptying fraction (EF) should have physiological importance in thrombus formation. The aim of this study was to validate a velocity vector imaging (VVI) method for quantification of the LAA function and to elucidate echocardiographic parameters that are related to the presence of LAA thrombus in patients with nonvalvular AF. METHODS: We measured left atrial (LA) dimension and LAEF by VVI using transthoracic echocardiography, and LAA emptying velocity, spontaneous echo contrast (SEC), and LAAEF by VVI using transesophageal echocardiography (TEE) in 142 consecutive patients with nonvalvular AF. The patients were divided into two groups according to the presence (n=38) or absence (n=104) of LAA thrombus. RESULTS: There was a good correlation between the VVI method and manual-tracing method for LAAEF and LAEF of patients with AF (r=0.97, r=0.96, respectively, p<0.001). LAAEF in AF with thrombus was significantly reduced compared with AF without thrombus (16.9±3.1% and 29.0±9.7%, p<0.001). In multivariate logistic regression analysis, LAAEF, SEC, and prior stroke were independent determinants of LAA thrombus. Using 20% of LAAEF as a cutoff value, the sensitivity was 92% and specificity was 88% for LAA thrombus. CONCLUSION: The VVI method was reliable in the measurement of LAAEF and LAEF compared with the manual-tracing method. LAAEF assessed by the VVI method using TEE was related to the presence of LAA thrombus.