Impact of Climate on the Incidence of Acute Coronary Syndrome　- Differences Between Japan and Thailand.

Background: Although there are many reports of temperature being associated with the onset of acute coronary syndrome (ACS), few studies have examined differences in ACS due to climatic differences between Japan and Thailand. The aim of this joint Japan-Thailand study was to compare patients with myocardial infarction in Japanese and Thai hospitals in different climates. Methods and Results: We estimated the climate data in 2021 for the Wakayama Prefecture and Chonburi Province, two medium-sized cities in Japan and Thailand, respectively, and ACS patients who were treated at the Wakayama Medical University (WMU) and Burapha University Hospital (BUH), the two main hospitals in these provinces (ACS patient numbers: WMU, n=177; BUH, n=93), respectively. In the Chonburi Province, although the average temperature was above 25℃, the number of ACS cases in BUH varied up to threefold between months (minimum: July, 4 cases; maximum: October, 14 cases). In Japan and Thailand, there was a mild to moderate negative correlation between temperature-atmospheric pressure at the onset of ACS, but different patterns for temperature-humidity (temperature-atmospheric pressure, temperature-humidity, and atmospheric pressure-humidity: correlation index; r=-0.561, 0.196, and -0.296 in WMU vs. r=-0.356, -0.606, and -0.502 in BUH). Conclusions: The present study suggests that other climatic conditions and factors, not just temperature, might be involved in the mechanism of ACS.

Intracoronary Near-Infrared Spectroscopy to Predict No-Reflow Phenomenon During Percutaneous Coronary Intervention in Acute Coronary Syndrome.

Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) can identify the lipid-rich lesions, described as high lipid-core burden index (LCBI). The aim of this study was to investigate the relation between lipid-core plaque (LCP) in the infarct-related lesion detected using NIRS-IVUS and no-reflow phenomenon during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). We investigated 371 patients with ACS who underwent NIRS-IVUS in the infarct-related lesions before PCI. The extent of LCP in the infarct-related lesion was calculated as the maximum LCBI for each of the 4-mm longitudinal segments (maxLCBI4mm) measured by NIRS-IVUS. The patients were divided into 2 groups using a maxLCBI4mm cut-off value of 400. The overall incidence of no-reflow phenomenon was 53 of 371 (14.3%). No-reflow phenomenon more frequently occurred in patients with maxLCBI4mm ≥400 compared with those with maxLCBI4mm<400 (17.5% vs 2.5%, p <0.001). After propensity score matching, multivariable logistic regression analysis demonstrated that maxLCBI4mm (odds ratio: 1.008; 95% confidence interval: 1.005 to 1.012, p <0.001) was independently associated with the no-reflow phenomenon. The maxLCBI4mm of 719 in the infarct-related lesion had the highest combined sensitivity (69.8%) and specificity (72.1%) for the identification of no-reflow phenomenon. In conclusion, in patients with ACS, maxLCBI4mm in the infarct-related lesion assessed by NIRS-IVUS was independently associated with the no-reflow phenomenon during PCI.

Diagnostic significance of paradoxical left ventricular hypertrophy in detecting cardiac amyloidosis.

Background: Cardiac amyloidosis (CA) progresses rapidly with a poor prognosis. Therefore, methods for early diagnosis that are easily accessible in any hospital, are required. We hypothesized that based on the pathology of CA, morphological left ventricular hypertrophy (LVH) without electrical augmentation, namely paradoxical LVH, could be used to diagnose CA. This study aimed to investigate whether paradoxical LVH has diagnostic significance in identifying CA in patients with LVH. Methods: Patients who presented with left ventricular (LV) wall thickness ≥ 12 mm on cardiac magnetic resonance (CMR) were enrolled from a multicentre CMR registry. Paradoxical LVH was defined as a LV wall thickness ≥ 12 mm on CMR, SV1 + RV5 < 3.5 mV, and a lack of secondary ST-T abnormalities. The diagnostic significance of paradoxical LVH in identifying CA was assessed. Results: Of the 110 patients enrolled, 30 (27 %) were diagnosed with CA and 80 (73 %) with a non-CA aetiology. The CA group demonstrated paradoxical LVH more frequently than the non-CA group (80 % vs. 16 %, P < 0.001). It was an independent predictor for detecting CA in patients with LVH (odds ratio: 33.44, 95 % confidence interval: 8.325-134.3, P < 0.001). The sensitivity, specificity, positive predict value, negative predict value and accuracy of paradoxical LVH for CA detection were 80 %, 84 %, 65 %, 92 % and 83 %, respectively. Conclusions: Paradoxical LVH can be used for identifying CA in patients with LVH. Our findings could contribute to the early diagnosis of CA, even in non-specialized hospitals.

Simultaneous hybrid off-pump coronary artery bypass grafting and transcatheter aortic valve implantation in elderly patients.

Purpose: Optimal strategy for transcatheter aortic valve implantation (TAVI) in patients with coronary artery disease (CAD) is unresolved. We evaluated the surgical outcomes of hybrid coronary artery bypass grafting (CABG) and TAVI in elderly patients. Methods: We retrospectively evaluated patients who underwent simultaneous TAVI and CABG at Wakayama Medical University, Japan. All patients underwent off-pump CABG (OPCAB) including minimally invasive cardiac surgery (MICS-CABG). In an earlier period, OPCAB + transfemoral TAVI (TF-TAVI) was the only method used, while in a later period, we introduced MICS-CABG and alternative approaches for TAVI. Results: Twenty-seven patients were enrolled, the average age was 83.6 ± 5.1 years. In the MICS-CABG and TAVI group, average patient age was higher (87.0 ± 3.1 years) than in the earlier group. Thirty-day and in-hospital mortalities were zero. Incomplete revascularization rate was 33.3% and one patient required percutaneous coronary intervention after the operation. Graft patency rate was 100%. In MICS-CABG group, the number of distal anastomoses was smaller (1.29, range 1-2), but the number of days required to re-starting walking and postoperative hospital stay were shorter, and the rate of discharge to home was higher (100%) than in the other groups. Conclusions: Although 33.3% of patients did not achieve complete revascularization, there was no 30-day or in-hospital mortality. TAVI and hybrid OPCAB, including MICS-CABG, were suggested to be feasible treatment in elderly patients.

Prevalence of low-attenuation plaques and statin therapy in plaque rupture type of acute coronary syndrome.

BACKGROUND: We sought to investigate the differences in coronary plaque morphology on coronary computed tomography angiography (CCTA) and medical therapy between acute coronary syndrome (ACS) and stable ischemic heart disease (SIHD). We also explored the relationship between plaque morphology on CCTA at the initial phase and lesion morphology in the acute phase of ACS. METHODS: In 5967 patients who underwent invasive coronary angiography, 58 ACS and 91 SIHD patients who had prior CCTA imaging of the culprit lesion and denied ischemic heart disease at CCTA scanning were enrolled. RESULTS: Although the prevalence of positive remodeling was not different (P = 0.27), low-attenuation plaques (LAP) on prior CCTA were significantly higher in ACS than in SIHD (52% vs. 24%, P < 0.01). The frequency of coronary stenosis grading did not differ between the two groups (P = 0.14). In ACS patients, the frequencies of plaque rupture and lipid-rich plaque assessed by optical coherence tomography (OCT) were significantly higher in LAP than in non-LAP (73% vs. 23%, P < 0.01; 82% and 23%, P < 0.01). Multivariate regression analysis revealed that statin use and LAP on prior CCTA were predictors of future ACS events (P < 0.01, and P < 0.05, respectively). CONCLUSIONS: LAP on CCTA, not positive arterial remodeling, and lack of statin therapy were associated with ACS development. In addition, LAP more frequently led to the development of the plaque rupture type of ACS compared with non-LAP. Lipid-lowering therapy with statins might be useful to prevent plaque rupture in patients with LAP regardless of coronary stenosis.

Serial changes of coronary flow reserve over one year after transcatheter aortic valve implantation in patients with severe aortic stenosis.

Background: Impaired coronary flow reserve (CFR) portends a poor prognosis in patients with aortic stenosis. The present study aims to investigate how CFR changes over one year after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis, and to explore factors related to the changes. Methods: Consecutive patients undergoing TAVI were registered. CFR in the left anterior descending artery was measured by transthoracic echocardiography on three occasions pre-TAVI, one-day post-TAVI, and one-year post-TAVI. Results: A total of 59 patients were enrolled, 46 of whom completed one-year follow-up. CFR was impaired in 35 (59.3%) patients pre-TAVI, but the impairment was only seen in 2 patients (4%) one-year post-TAVI. CFR value improved from 1.75 (1.50-2.10) cm/s pre-TAVI, to 2.00 (1.70-2.30) one-day post-TAVI, and further to 2.60 (2.30-3.10) one-year post-TAVI (P < 0.001). The median difference in CFR between pre-TAVI and one-year post-TAVI was 0.90 (0.53-1.20). Patients with significant improvement of CFR (more than the median value of 0.9) had larger aortic valve area (1.55 [1.38-1.92] vs. 1.36 cm2 [1.26-1.69], P = 0.042) and greater improvement in left ventricular ejection fraction (3.10 [-1.67-4.24] vs. -1.46 [-3.42-1.48] percentage points, P = 0.019) than those without. Conclusions: CFR is impaired in a considerable proportion of patients with severe aortic stenosis, but improvement is seen immediately after TAVI, and one year later. Patients with significant improvement of CFR had larger aortic valve area and greater increase in left ventricular ejection fraction after TAVI.

Effect of Atherectomy on Lesion Preparation in Heavily Calcified Coronary Artery Disease.

Background: Percutaneous coronary intervention (PCI) of heavily calcified lesions remains challenging. This study examined whether calcified lesion preparation is better with an ablation-based than balloon-based technique. Methods and Results: Results of lesion preparations with and without atherectomy devices were compared in 121 patients undergoing optical coherence tomography (OCT)-guided PCI of heavily calcified lesions. Lesion preparation was performed with the ablation-based technique in 59 patients (atherectomy group) and with the balloon-based technique in 62 patients (balloon group). Lower grades of angiographic coronary dissections (National Heart, Lung, and Blood Institute [NHLBI] classification) occurred in the atherectomy than balloon group (atherectomy group: none, 33%; NHLBI A, 59%; B, 8%; C, 0%; D, 0%; balloon group: none, 1%; NHLBI A, 24%; B, 58%; C, 15%; D, 2%). On OCT, a large dissection was less common (49% vs. 90%; P<0.001) and calcium fractures were more frequent (75% vs. 18%; P<0.001) in the atherectomy than balloon group. In multivariable analyses, the ablation-based technique was associated with a lower grade of angiographic coronary dissection (adjusted odds ratio [aOR] 0.04; 95% confidence interval [CI] 0.01-0.12; P<0.001), a lower incidence of OCT-detected large dissection (aOR 0.09; 95% CI 0.03-0.30; P<0.001), and a higher incidence of OCT-detected calcium fracture (aOR 18.19; 95% CI 6.45-58.96; P<0.001). Conclusions: The ablation-based technique outperformed the balloon-based technique in the lesion preparation of heavily calcified lesions.

Vascular Response After Everolimus-Eluting Stent in Acute Myocardial Infarction Caused by Calcified Nodule.

BACKGROUND: Patients with acute myocardial infarction (AMI) caused by calcified nodules (CN) have worse clinical outcomes following primary percutaneous coronary intervention (PCI). This study investigated the late vascular response after everolimus-eluting stent (EES) implantation assessed by optical coherence tomography (OCT) in patients with AMI caused by CN, by comparing with plaque rupture (PR) and plaque erosion (PE).Methods and Results: Based on the OCT findings in AMI culprit lesions before PCI, a total of 141 patients were categorized into 3 groups (PR, PE, or CN), and the OCT findings immediately and 10 months after PCI were compared. The frequency of PR, PE, and CN was 85 (60%), 45 (32%), and 11 patients (8%), respectively. In the 10-month follow-up OCT, the frequency of lesions with uncovered struts and lesions with malapposed struts were highest in the CN group, followed by the PR and PE groups (82% vs. 52% vs. 40%, P=0.042 and 73% vs. 26% vs. 16%, P<0.001, respectively). The incidence of intra-stent thrombus, re-appearance of CN within the stent, and target lesion revascularization were higher in the CN group compared with the PR and PE groups (36% vs. 9% vs. 7%, P=0.028; 27% vs. 0% vs. 0%, P<0.001; and 18% vs. 2% vs. 2%, P=0.024, respectively). CONCLUSIONS: Late arterial healing response at 10 months after EES implantation in the CN was worse compared with PR and PE in patients with AMI.

Telecardiology in Rural Practice: Global Trends.

The management of cardiovascular diseases in rural areas is plagued by the limited access of rural residents to medical facilities and specialists. The development of telecardiology using information and communication technology may overcome such limitation. To shed light on the global trend of telecardiology, we summarized the available literature on rural telecardiology. Using PubMed databases, we conducted a literature review of articles published from January 2010 to December 2020. The contents and focus of each paper were then classified. Our search yielded nineteen original papers from various countries: nine in Asia, seven in Europe, two in North America, and one in Africa. The papers were divided into classified fields as follows: seven in tele-consultation, four in the telemedical system, four in the monitoring system, two in prehospital triage, and two in tele-training. Six of the seven tele-consultation papers reported the consultation from rural doctors to urban specialists. More reports of tele-consultations might be a characteristic of telecardiology specific to rural practice. Further work is necessary to clarify the improvement of cardiovascular outcomes for rural residents.

Prevalence of myocardial perfusion scintigraphy derived ischemia in coronary lesions with discordant fractional flow reserve and non-hyperemic pressure ratios.

BACKGROUND: Whether a coronary lesion with discordant fractional flow reserve (FFR) and non-hyperemic pressure ratios (NHPRs) causes myocardial ischemia remains unclear. This study investigates the prevalence of myocardial ischemia as assessed by myocardial perfusion scintigraphy (MPS) in coronary lesions with discordant FFR and instantaneous wave-free ratio (iFR), and, additionally, other NHPRs: resting full-cycle ratio (RFR), diastolic pressure ratio (dPR), and resting Pd/Pa. METHODS: A total of 484 coronary arteries in 295 patients with stable coronary artery disease that underwent MPS and invasive physiological pressure measurements were categorized into four groups (FFR+/NHPR+, FFR+/NHPR-, FFR-/NHPR+, and FFR-/NHPR-) using the respective cut-off values of FFR ≤ 0.80, iFR ≤ 0.89, RFR ≤ 0.89, dPR < 0.89, and Pd/Pa ≤ 0.92. The proportions of MPS-derived myocardial ischemia in a relevant myocardial territory were compared between the four groups. RESULTS: In total, 175 (36%), 61(13%), 35(7%) and 213(44%) vessels were classified into FFR+/iFR+, FFR+/iFR-, FFR-/iFR+ and FFR-/iFR- groups, respectively. The FFR+/iFR+ group had the highest proportion of MPS-derived ischemia (70%), followed by the FFR+/iFR- group (38%), the FFR-/iFR+ group (23%), and the FFR-/iFR- group (10%) (P < 0.001). Similar proportions of MPS-derived ischemia were found when RFR. (70%, 34%, 24%, and 10%, P < 0.001), dPR (70%, 38%, 26%, and 10%, P < 0.001), and Pd/Pa (70%, 31%, 22%, and 10%, P < 0.001) were used in place of iFR. CONCLUSIONS: The prevalence of MPS-derived myocardial ischemia in coronary lesions with discordance between FFR and NHPRs is lower than those with concordantly positive FFR and NHPRs, but higher than those with concordantly negative FFR and NHPRs.

Usefulness of optical coherence tomography with angiographic coregistration in the guidance of coronary stent implantation.

Optical coherence tomography (OCT)-angiography coregistration during stent implantation may be useful to avoid geographical mismatch and incomplete lesion coverage. Untreated lipid-rich plaque at stent edge is associated with subsequent stent edge restenosis. The present study sought to compare the frequency of untreated lipid-rich plaque at the stent edge between OCT-guided percutaneous coronary intervention (PCI) with and without OCT-angiography coregistration. We investigated 398 patients who underwent OCT-guided stent implantation (n = 198 in the coregistration group, and n = 200 in the no coregistration group). In OCT after PCI, untreated lipid-lich plaque was identified by the maximum lipid arc > 180˚ in the 5-mm stent edge segment. The PCI-targeted lesion characteristics and stent length were not different between the coregistration group and the no coregistration group. The frequency of untreated lipid-rich plaque in either proximal or distal stent edge segment was significantly lower in the coregistration group than in the no coregistration group (16% vs. 26%, P = 0.015). The frequency of stent-edge dissection (5% vs. 6%, P = 0.516) and untreated stenosis (2% vs. 3%, P = 0.724) was low and without significant differences between the two groups. In OCT-guided PCI, the use of OCT-angiography coregistration was associated with a reduced frequency of untreated lipid-rich plaque at stent edges. OCT-angiography coregistration has a positive impact on PCI results.

Real-time venography-guided extrathoracic puncture technique for cardiovascular implantable electronic device implantation.

Central venous access is an essential technique for cardiovascular implantable electronic device (CIED) implantation, and the use of axillary vein approach has recently been increasing. This study sought to examine whether real-time venography-guided extrathoracic puncture facilitates the procedure. We retrospectively analyzed 179 consecutive patients who underwent CIED implantation using the axillary vein puncture method. Patients were divided into two groups: the conventional method group (CG, n = 107) and the real-time venography-guided group (RG, n = 82). The application of real-time venography was at the discretion of individual operators. Operators with experience of less than 50 CIED implantations were defined as inexperienced operators in this study. Puncture duration and number of attempts were significantly less in the RG group than in the CG group (283 ± 198 vs. 421 ± 361 s, p < 0.01, and 3.19 ± 2.00 vs. 4.18 ± 2.85, p < 0.01). These benefits of real-time venography were observed in inexperienced operators, but not in experienced operators. In addition, the success rate without extra attempts at puncture was higher in the RG group (54% vs. 32%, p < 0.01). Although the total amount of contrast medium was higher in the RG group (16.3 ± 4.1 mL vs. 11.9 ± 6.6 mL, p < 0.01), serum levels of creatinine pre- and post-operation were not different in the two groups (p = NS). We concluded that real-time venography is a safe and effective method for axillary vein puncture, especially in inexperienced operators.

Near-infrared spectroscopy to predict microvascular obstruction after primary percutaneous coronary intervention.

BACKGROUND: Successful restoration of epicardial coronary artery patency by primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI) does not always lead to adequate reperfusion at the microvascular level. AIMS: This study sought to investigate the association between lipid-rich coronary plaque identified by near-infrared spectroscopy combined with intravascular ultrasound (NIRS-IVUS) and microvascular obstruction (MVO) detected by cardiac magnetic resonance imaging (MRI) after PPCI for STEMI. METHODS: We investigated 120 patients with STEMI undergoing PPCI. NIRS-IVUS was used to measure the maximum lipid core burden index in 4 mm (maxLCBI4 mm) in the infarct-related lesions before PPCI. Delayed contrast-enhanced cardiac MRI was performed to evaluate MVO one week after PPCI. RESULTS: MVO was identified in 40 (33%) patients. MaxLCBI4 mm in the infarct-related lesion was significantly larger in the MVO group compared with the no-MVO group (median [interquartile range]: 745 [522-853] vs 515 [349-698], p<0.001). A multivariable logistic regression model showed that maxLCBI4 mm was an independent predictor of MVO (odds ratio: 24.7 [95% confidence interval: 2.5-248.0], p=0.006). Receiver operating characteristic curve analysis demonstrated that maxLCBI4 mm >600 was the optimal cut-off value to predict MVO (Youden index=0.44 and area under the curve=0.71) with a sensitivity of 75% and a specificity of 69%. CONCLUSIONS: Lipid content measured by NIRS in the infarct-related lesions was associated with the occurrence of MVO after PPCI in STEMI.

Noninvasive estimation of impaired left ventricular untwisting velocity by peak early diastolic intra-ventricular pressure gradients using vector flow mapping.

BACKGROUND: Introduction of vector flow mapping (VFM) based on the combination of color Doppler and speckle-tracking echocardiography provides noninvasive assessment of early diastolic intra-ventricular pressure gradient (ED-IVPG). The purpose of this study was to evaluate the value of peak ED-IVPG measurement just after aortic valve closure using VFM for noninvasive estimation of impaired LV untwisting velocity as the index of LV relaxation in the clinical setting. METHODS AND RESULTS: The study included 65 consecutive patients in whom echocardiography was performed for the assessment of LV function. We assessed peak ED-IVPG between LV apex and base by VFM analysis software. We also measured peak LV untwisting velocity and LV twisting by speckle-tracking strain analysis. Peak ED-IVPG was successfully and quickly assessed in all the study patients. Peak ED-IVPG was significantly reduced in patients with impaired peak LV untwisting velocity (< 70 degrees/s) compared with patients without impaired peak LV untwisting velocity. The receiver operating characteristic analysis showed the best cut-off value of peak ED-IVPG for determining impaired peak LV untwisting velocity was 0.40 mmHg (sensitivity 81%, specificity 74%, and area under the curve 0.81). There was a well correlation between peak ED-IVPG and peak LV untwisting velocity (r = 0.64, p < 0.0001). CONCLUSIONS: The present results suggest that peak ED-IVPG just after aortic valve closure measured by VFM may be used as noninvasive index for estimation of impaired LV untwisting velocity in the clinical setting.

Optical coherence tomography detection of vulnerable plaques at high risk of developing acute coronary syndrome.

AIMS: The ability of optical coherence tomography (OCT) to detect plaques at high risk of developing acute coronary syndrome (ACS) remains unclear. The aim of this study was to evaluate the association between non-culprit plaques characterized as both lipid-rich plaque (LRP) and thin-cap fibroatheroma (TCFA) by OCT and the risk of subsequent ACS events at the lesion level. METHODS AND RESULTS: In 1378 patients who underwent OCT, 3533 non-culprit plaques were analysed for the presence of LRP (maximum lipid arc > 180°) and TCFA (minimum fibrous cap thickness < 65 µm). The median follow-up period was 6 years [interquartile range (IQR): 5-9 years]. Seventy-two ACS arose from non-culprit plaques imaged by baseline OCT. ACS was more often associated with lipidic plaques that were characterized as both LRP and TCFA vs. lipidic plaques that did not have these characteristics [33% vs. 2%, hazard ratio 19.14 (95% confidence interval: 11.74-31.20), P < 0.001]. The sensitivity and specificity of the presence of both LRP and TCFA for predicting ACS was 38% and 97%, respectively. A larger maximum lipid arc [1.01° (IQR: 1.01-1.01°)], thinner minimum fibrous cap thickness [0.99 µm (IQR: 0.98-0.99 µm)], and smaller minimum lumen area [0.78 mm2 (IQR: 0.67-0.90 mm2), P < 0.001] were independently associated with ACS. CONCLUSION: Non-culprit plaques characterized by OCT as both LRP and TCFA were associated with an increased risk of subsequent ACS at the lesion level. Therefore, OCT might be able to detect vulnerable plaques.

Global longitudinal strain evaluated by speckle-tracking echocardiography as a surrogate marker for predicting replacement fibrosis detected by magnetic resonance-late gadolinium enhancement in patients with nonischemic cardiomyopathy.

PURPOSE: This study aimed to investigate whether left ventricular (LV) global longitudinal strain (GLS) evaluated by speckle-tracking echocardiography (STE) can be used as a surrogate marker for the detection of replacement fibrosis by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) in patients with nonischemic cardiomyopathy (NICM). METHODS: This study analyzed 41 NICM patients who successfully underwent both STE and CMR, and were divided into those with (Group A, n = 18) and those without CMR-LGE (Group B, n = 23). Echocardiographic indexes, including GLS, were compared between the two groups. RESULTS: No significant differences were observed in LV end-diastolic and end-systolic volume indexes, LV ejection fraction, mitral E/A, deceleration time, E/e', left atrial volume index, and the systolic trans-tricuspid pressure gradient between Groups A and B. STE-GLS was significantly worse in Group A than in Group B (-7.6% ± 3.0% vs -9.9% ± 3.2%, P = .01). Receiver operating characteristic curve analysis showed that STE-GLS of -7.9% was the best cut-off value for detection of CMR-LGE (sensitivity, 78%; specificity, 74%; and area under the curve, 0.74). CONCLUSIONS: STE-GLS may be a potential surrogate marker for the detection of CMR-LGE-derived replacement fibrosis in patients with NICM.

Impact of instantaneous wave-free ratio on graft failure after coronary artery bypass graft surgery.

BACKGROUND: We aimed to assess an impact of instantaneous wave-free ratio (iFR) on a graft failure after coronary artery bypass grafting (CABG). METHODS AND RESULTS: A total of 131 coronary arteries from 88 patients who underwent invasive coronary angiography, intracoronary pressure measurements, CABG, and scheduled follow-up coronary computed tomography angiography within one year were investigated. All studied arteries had FFR <0.80. The rate of graft failure was significantly higher in vessels with negative iFR (>0.89) than in those with positive iFR (<0.89) (25.7% vs. 7.3%, p = 0.012). The graft failure rates increased as the preoperative iFR values rose (iFR <0.80, 3.3%; iFR: 0.80-0.84, 5.6%; iFR: 0.85-0.89, 16.0%; iFR: 0.90-0.94, 28.0%; and iFR: 0.95-1.00, 50.0%; p = 0.002). A cut-off value of iFR to predict graft failures was determined as 0.84 by receiver-operating characteristic curve analysis with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 88%, 62%, 25%, 97%, and 66%, respectively. CONCLUSIONS: The risk of graft failure becomes higher, as the preoperative iFR increases. The graft failure is significantly more frequent when a bypass graft is anastomosed on vessels with negative iFR than those with positive iFR.

Prognostic value of tissue-tracking mitral annular displacement by speckle-tracking echocardiography in asymptomatic aortic stenosis patients with preserved left ventricular ejection fraction.

BACKGROUND: Tissue-tracking mitral annular displacement (TMAD) by speckle-tracking echocardiography provides rapid and simple assessment of left ventricular (LV) longitudinal deformation. The purpose of this study was to evaluate the value of TMAD for the assessment of LV longitudinal deformation in patients with severe AS and preserved LV ejection fraction (LVEF). METHODS: We studied 44 patients with severe AS preserved and LVEF in whom TMAD was assessed. Using TMAD analysis software, the base-to-apex displacement of automatically defined mid-point of mitral annular line in four-chamber view was quickly assessed, and the percentage of its displacement to LV length at end-diastole (%TMAD) was calculated. We investigated the association between %TMAD and the cardiac events including appearance of symptom (dyspnea on exertion and hospitalization due to heart failure), decreased LVEF (< 50%), and cardiac death. RESULTS: During follow-up, the cardiac events developed in 16 (36%) of 44 patients. %TMAD was significantly impaired in patients with the cardiac events compared with those without the cardiac events (9.6 ± 1.9 vs 12.1 ± 2.6, p = 0.002). The cardiac events were predicted by %TMAD (HR 0.68, 95% CI 0.54-0.85; p = 0.0012). CONCLUSIONS: The present study suggests that TMAD easily and rapidly estimated by speckle-tracking echocardiography may be used as a simple method to predict occurrence of the cardiac events in asymptomatic severe AS patients with preserved LVEF.

Prevalence, Features, and Prognosis of Artery-to-Artery Embolic ST-Segment-Elevation Myocardial Infarction: An Optical Coherence Tomography Study.

Background The major underlying mechanisms contributing to acute coronary syndrome are plaque rupture, plaque erosion, and calcified nodule. Artery-to-artery embolic myocardial infarction (AAEMI) was defined as ST-segment-elevation myocardial infarction caused by migrating thrombus formed at the proximal ruptured plaque. The aim of this study was to investigate the prevalence and clinical features of AAEMI by using optical coherence tomography. Methods and Results This study retrospectively enrolled 297 patients with ST-segment-elevation myocardial infarction who underwent optical coherence tomography before percutaneous coronary intervention. Patients were divided into 4 groups consisting of plaque rupture, plaque erosion, calcified nodule, and AAEMI according to optical coherence tomography findings. The prevalence of AAEMI was 3.4%. The culprit vessel in 60% of patients with AAEMI was right coronary artery. Minimum lumen area at the culprit site was larger in AAEMI compared with plaque rupture, plaque erosion, and calcified nodule (4.0 mm2 [interquartile range (IQR), 2.2-4.9] versus 1.0 mm2 [IQR, 0.8-1.3] versus 1.0 mm2 [IQR, 0.8-1.2] versus 1.1 mm2 [IQR, 0.7-1.6], P<0.001). Lumen area at the rupture site was larger in patients with AAEMI compared with patients with plaque rupture (4.4 mm2 [IQR, 2.5-6.7] versus 1.5 mm2 [IQR, 1.0-2.4], P<0.001). In patients with AAEMI, the median minimum lumen area at the occlusion site was 1.2 mm2 (IQR, 1.0-2.1), 40% of them had nonstent strategy, and the 3-year major adverse cardiac event rate was 0%. Conclusions AAEMI is a rare cause for ST-segment-elevation myocardial infarction and has unique morphological features of plaque including larger lumen area at rupture site and smaller lumen area at the occlusion site.

Comparison of Optical Flow Ratio and Fractional Flow Ratio in Stent-Treated Arteries Immediately After Percutaneous Coronary Intervention.

BACKGROUND: Optical flow ratio (OFR) is a recently developed method for functional assessment of coronary artery disease based on computational fluid dynamics of vascular anatomical data from intravascular optical coherence tomography (OCT). The purpose of this study was to investigate the relationship between OFR and fractional flow reserve (FFR) in stent-treated arteries immediately after percutaneous coronary intervention (PCI).Methods and Results:The OFR and FFR were measured in 103 coronary arteries immediately after successful PCI with a stent. An increase in the OFR and FFR values within the stent was defined as in-stent ∆OFR and ∆FFR, respectively. The values of FFR and OFR were 0.89±0.06 and 0.90±0.06, respectively. OFR was highly correlated with FFR (r=0.84, P<0.001). OFR showed a good agreement with FFR, presenting small values of mean difference and root-mean-squared deviation (FFR-OFR: -0.01±0.04). In-stent ∆OFR showed a moderate correlation (r=0.69, P<0.001) and good agreement (in-stent ∆FFR - in-stent ∆OFR: 0.00±0.02) with in-stent ∆FFR. CONCLUSIONS: OFR showed a high correlation and good agreement with FFR in stent-treated arteries immediately after PCI.