Network Analysis of Cardiac Remodeling by Primary Mitral Regurgitation Emphasizes the Role of Diastolic Function.

BACKGROUND: Topological data analysis (TDA) can generate patient-patient similarity networks by analyzing large, complex data and derive new insights that may not be possible with standard statistics. OBJECTIVES: The purpose of this paper was to discover novel phenotypes of chronic primary mitral regurgitation (MR) patients and to analyze their clinical implications using network analysis of echocardiographic data. METHODS: Patients with chronic moderate to severe primary MR were prospectively enrolled from 11 Asian tertiary hospitals (n = 850; mean age 56.9 ± 14.2 years, 57.9% men). We performed TDA to generate network models using 14 demographic and echocardiographic variables. The patients were grouped by phenotypes in the network, and the prognosis was compared by groups. RESULTS: The network model by TDA revealed 3 distinct phenogroups. Group A was the youngest with fewer comorbidities but increased left ventricular (LV) end-systolic volume, representing compensatory LV dilation commonly seen in chronic primary MR. Group B was the oldest with high blood pressure and a predominant diastolic dysfunction but relatively preserved LV size, an unnoticed phenotype in chronic primary MR. Group C showed advanced LV remodeling with impaired systolic, diastolic function, and LV dilation, indicating advanced chronic primary MR. During follow-up (median 3.5 years), 60 patients received surgery for symptomatic MR or died of cardiovascular causes. Kaplan-Meier curves demonstrated that although group C had the worst clinical outcome (P < 0.001), group B, characterized by diastolic dysfunction, had an event-free survival comparable to group A despite preserved LV chamber size. The grouping information by the network model was an independent predictor for the composite of MR surgery or cardiovascular death (adjusted HR: 1.918; 95% CI: 1.257-2.927; P = 0.003). CONCLUSIONS: The patient-patient similarity network by TDA visualized diverse remodeling patterns in chronic primary MR and revealed distinct phenotypes not emphasized currently. Importantly, diastolic dysfunction deserves equal attention when understanding the clinical presentation of chronic primary MR.

Feasibility of tissue-tracking mitral annular displacement in single four-chamber view as a simple index of left ventricular longitudinal deformation.

BACKGROUND: Left ventricular global longitudinal strain (LVGLS) has prognostic value for adverse cardiac events. Application of speckle-tracking technology to mitral annulus provides easy assessment of tissue-tracking mitral annular displacement (TMAD) in apical four-chamber view. The study aimed to examine whether TMAD can be used as a simple index of LV longitudinal deformation in patients with and without preserved ejection fraction (EF). METHODS: The study population consisted of 95 consecutive subjects. GLS was assessed from three apical views. TMAD was evaluated as the base-to-apex displacement of septal (TMADsep), lateral (TMADlat), and mid-point of annular line (TMADmid) in apical 4-chamber view. The percentage of TMADmid to LV length from the mid-point of mitral annuls to the apex at end-diastole (%TMADmid) was calculated. We compared each TMAD parameter with GLS by linear regression analysis, and analyzed each TMAD parameter by receiver operating characteristic (ROC) curve to detect impaired LV longitudinal deformation (|GLS|< 15.0%). RESULTS: There were good correlations between each TMAD parameter and GLS (TMADsep: r2 = 0.59, p < 0.01. TMADlat: r2 = 0.65, p < 0.01. TMADmid: r2 = 0.68, p < 0.01. %TMADmid: r2 = 0.75, p < 0.01). According to ROC curve, %TMADmid < 10.5% was the best cut-off value in determining impaired LV longitudinal deformation (|GLS|≤ 15.0%) with a sensitivity of 95% and a specificity of 93%. The area under the curve (AUC) of %TMADmid was 0.98 (95% confidence intervals (CI) 0.93-0.99). CONCLUSIONS: TMAD using speckle-tracking echocardiography quickly estimated from single apical four-chamber view can be used as a simple index for detection of impaired LV longitudinal deformation in patients with and without preserved EF.

Impact of cavotricuspid isthmus depth on the ablation index for successful first-pass typical atrial flutter ablation.

Cavotricuspid isthmus (CTI) linear ablation has been established as the treatment for typical atrial flutter. Recently, ablation index (AI) has emerged as a novel marker for estimating ablation lesions. We investigated the relationship between CTI depth and ablation parameters on the procedural results of typical atrial flutter ablation. A total of 107 patients who underwent CTI ablation were retrospectively enrolled in this study. All patients underwent computed tomography before catheter ablation. From the receiver-operating curve, the best cut-off value of CTI depth was < 4.1 mm to predict first-pass success. Although the average AI was not different between deep CTI (DC; CTI depth ≥ 4.1) and shallow CTI (SC; CTI depth < 4.1), DC required a longer ablation time and showed a lower first-pass success rate (p < 0.01). In addition, the catheter inversion technique was more frequently required in the DC (p < 0.01). The lowest AI sites of the first-pass CTI line were determined in both the ventricular (2/3 segment of CTI) and inferior vena cava (IVC, 1/3 segment of CTI) sides. The best cut-off values of the weakest AIs at the ventricular and IVC sides for predicting first-pass success were > 420 and > 386, respectively. Among patients with these cut-off values, the first-pass success rate was 89% in the SC and 50% in the DC (p < 0.01). Although ablation parameters were not significantly different, the first-pass success rate was lower in the DC than in the SC. Further investigation might be required for better outcomes in deep CTIs.

Implications of multiple late gadolinium enhancement lesions on the frequency of left ventricular reverse remodeling and prognosis in patients with non-ischemic cardiomyopathy.

BACKGROUND: Non-ischemic cardiomyopathy (NICM) is a heterogeneous disease, and its prognosis varies. Although late gadolinium enhancement (LGE)-cardiovascular magnetic resonance (CMR) demonstrates a linear pattern in the mid-wall of the septum or multiple LGE lesions in patients with NICM, the therapeutic response and prognosis of multiple LGE lesions have not been elucidated. This study aimed to investigate the frequency of left ventricular (LV) reverse remodeling (LVRR) and prognosis in patients with NICM who have multiple LGE lesions. METHODS: This single-center retrospective study included 101 consecutive patients with NICM who were divided into 3 groups according to LGE-CMR results: patients without LGE (no LGE group = 48 patients), patients with a typical mid-wall LGE pattern (n = 29 patients), and patients with multiple LGE lesions (n = 24 patients). LVRR was defined as an increase in LV ejection fraction (LVEF) ≥ 10 % and a final value of LVEF > 35 %, which was accompanied by a decrease in LV end-systolic volume ≥ 15 % at 12-month follow-up using echocardiography. The frequency of composite cardiac events, defined as sudden cardiac death (SCD), aborted SCD (non-fatal ventricular fibrillation, sustained ventricular tachycardia, or adequate implantable cardioverter-defibrillator therapies), and heart failure death or hospitalization for worsening heart failure, were summarized and compared between the groups. RESULTS: Among the 3 groups, the frequency of LVRR was significantly lower in the multiple lesions group than in the no LGE and mid-wall groups (no LGE vs. mid-wall vs. multiple lesions: 49 % vs. 52 % vs. 19 %, p = 0.03). There were 24 composite cardiac events among the patients: 2 in patients without LGE (hospitalization for worsening heart failure; 2), 7 in patients of the mid-wall group (SCD; 1, aborted SCD; 1 and hospitalization for worsening heart failure; 5), and 15 in patients of the multiple lesions group (SCD; 1, aborted SCD; 8 and hospitalization for worsening heart failure; 6). The multiple LGE lesions was an independent predictor of composite cardiac events (hazard ratio: 11.40 [95 % confidence intervals: 1.49-92.01], p = 0.020). CONCLUSIONS: Patients with multiple LGE lesions have a higher risk of cardiac events and poorer LVRR. The LGE pattern may be useful for an improved risk stratification in patients with NICM.

Impact of left ventricular ejection fraction and preoperative hemoglobin level on perioperative adverse cardiovascular events in noncardiac surgery.

The prediction of a perioperative adverse cardiovascular event (PACE) is an important clinical issue in the medical management of patients undergoing noncardiac surgery. Although several predictors have been reported, simpler and more practical predictors of PACE have been needed. The aim of this study was to investigate the predictors of PACE in noncardiac surgery. We retrospectively analyzed 723 patients who were scheduled for elective noncardiac surgery and underwent preoperative examinations including 12-lead electrocardiography, transthoracic echocardiography, and blood test. PACE was defined as cardiac death, non-fatal myocardial infarction, unstable angina, congestive heart failure, arrhythmia attack that needs emergency treatment (rapid atrial fibrillation, ventricular tachycardia, and bradycardia), acute pulmonary embolism, asystole, pulseless electrical activity, or stroke during 30 days after surgery. PACE occurred in 54 (7.5%) of 723 patients. High-risk operation (11% vs. 3%, p = 0.003) was more often seen, left ventricular ejection fraction (LVEF) (55 ± 8% vs. 60 ± 7%, p = 0.001) and preoperative hemoglobin level (11.8 ± 2.2 g/dl vs. 12.7 ± 2.0 g/dl, p = 0.001) were lower in patients with PACE compared to those without PACE. By multivariate logistic regression analysis, high-risk operation (odds ratio (OR): 7.05, 95% confidence interval (CI) 2.16-23.00, p = 0.001), LVEF (OR 1.06, every 1% decrement, 95% CI 1.03-1.09, p = 0.001), and preoperative hemoglobin level (OR 1.22, every 1 g/dl decrement, 95% CI 1.07-1.39, p = 0.003) were identified as independent predictors of PACE. Receiver operating characteristic analysis demonstrated that LVEF of 58% (sensitivity = 80%, specificity = 61%, area under the curve (AUC) = 0.723) and preoperative hemoglobin level of 12.2 g/dl (sensitivity = 63%, specificity = 64%, AUC = 0.644) were optimal cut-off values for predicting PACE. High-risk operation, reduced LVEF, and reduced preoperative hemoglobin level were independently associated with PACE in patients undergoing noncardiac surgery.

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.

Discrepancy of Aortic Valve Area Measurements by Doppler vs. Biplane Stroke Volume Measurements and Utility of Combining the Different Areas in Aortic Valve Stenosis　- The Asian Valve Registry.

BACKGROUND: The aortic valve area index (AVAI) in aortic stenosis (AS) is measured by echocardiography with a continuity equation using the stroke volume index by Doppler (SVIDoppler) or biplane Simpson (SVIBiplane) method. AVAIDopplerand AVAIBiplaneoften show discrepancy due to differences between SVIDopplerand SVIBiplane. The degree of discrepancy and utility of combined AVAIs have not been investigated in a large population of AS patients, and the characteristics of subjects with larger discrepancies are unknown.Methods and Results:We studied 820 patients with significant AS (AVADoppler<1.5 cm2) enrolled in the Asian Valve Registry, a prospective multicenter registry at 12 Asian centers. All-cause death and aortic valve replacement were defined as events. SVIDopplerwas significantly larger than SVIBiplane(49±11 vs. 39±11 mL/m2, P<0.01) and AVAIDopplerwas larger than AVAIBiplane(0.51±0.15 vs. 0.41±0.14 cm2/m2, P<0.01). An increase in (AVAIDoppler- AVAIBiplane) correlated with shorter height, lower weight, older age, smaller left ventricular (LV) diameter and increased velocity of ejection flow at the LV outflow tract. Severe AS by AVAIDoppleror AVAIBiplaneenabled prediction of events, and combining these AVAIs improved the predictive value of each. CONCLUSIONS: Discrepancy in AVAI by Doppler vs. biplane method was significantly more pronounced with increased LV outflow tract flow velocity, shorter height, lower weight, older age and smaller LV cavity dimensions. Combining the AVAIs enabled mutual and incremental value in predicting events.

NIRS-IVUS for Differentiating Coronary Plaque Rupture, Erosion, and Calcified Nodule in Acute Myocardial Infarction.

OBJECTIVES: This study sought to investigate the ability of combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) to differentiate plaque rupture (PR), plaque erosion (PE), or calcified nodule (CN) in acute myocardial infarction (AMI). BACKGROUND: Most acute coronary syndromes occur from coronary thrombosis based on PR, PE, or CN. In vivo differentiation among PR, PE, and CN is a major challenge for intravascular imaging. METHODS: The study enrolled 244 patients with AMI who had a de novo culprit lesion in a native coronary artery. The culprit lesions were assessed by both NIRS-IVUS and optical coherence tomography (OCT). Maximum lipid core burden index in 4 mm (maxLCBI4mm) was measured by NIRS. Plaque cavity and convex calcium was detected by IVUS. The OCT diagnosis of PR (n = 175), PE (n = 44), and CN (n = 25) was used as a reference standard. RESULTS: In the development cohort, IVUS-detected plaque cavity showed a high specificity (100%) and intermediate sensitivity (62%) for identifying OCT-PR. IVUS-detected convex calcium showed a high sensitivity (93%) and specificity (100%) for identifying OCT-CN. NIRS-measured maxLCBI4mm was largest in OCT-PR (705 [interquartile range (IQR): 545 to 854]), followed by OCT-CN (355 [IQR: 303 to 478]) and OCT-PE (300 [IQR: 126 to 357]) (p < 0.001). The optimal cutoff value of maxLCBI4mm was 426 for differentiating between OCT-PR and -PE; 328 for differentiating between OCT-PE and -CN; and 579 for differentiating between OCT-PR and -CN. In the validation cohort, the NIRS-IVUS classification algorithm using plaque cavity, convex calcium, and maxLCBI4mm showed a sensitivity and specificity of 97% and 96% for identifying OCT-PR, 93% and 99% for OCT-PE, and 100% and 99% for OCT-CN, respectively. CONCLUSIONS: By evaluating plaque cavity, convex calcium, and maxLCBI4mm, NIRS-IVUS can accurately differentiate PR, PE, and CN.

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.

Expression of Cyclophilin A in Coronary Artery Plaque with Intraplaque Hemorrhage Is More Frequent in Deceased Patients Who Had Impaired Kidney Function.

Patients with impaired kidney function have a high frequency of intraplaque hemorrhage (IPH) in their coronary arteries. Levels of cyclophilin A (CyPA), an indirect matrix metalloproteinase inducer, are increased in deceased patients who had impaired kidney function. In this study, we have examined the relationship between IPH and CyPA.We examined 47 samples of coronary plaque from 27 cadavers with coronary stenosis. These sections, all with > 50% coronary stenosis, were stained with an antibody against CyPA and the expression of CyPA was semi-quantified. Cadavers and plaques were classified into one of two groups depending on the presence or absence of IPH. IPH was defined as the presence of red blood cells stained with hematoxylin and eosin (HE) indicative of overt acute hemorrhage.In an individual analysis, estimation of glomerular filtration rate (eGFR) in the IPH group was significantly lower than that in the non-IPH group (P = 0.002). In a histological analysis, the percentage of stained area of CyPA in the IPH group was significantly higher than that in the non-IPH group (P < 0.0001).IPH was associated with a significantly higher expression of CyPA in this study. In addition, patients with IPH in their coronary arteries had significantly impaired kidney function.

Assessment of myocardial damage after acute myocardial infarction by diastolic deceleration time of coronary flow velocity using echocardiography and contrast-enhanced magnetic resonance imaging.

BACKGROUND: There are limited data available regarding the use of diastolic deceleration time (DDT) of three major arteries measured by transthoracic echocardiography (TTE) for assessing coronary microvascular damage after acute myocardial infarction (AMI). Therefore, we aimed to compare the DDT of three major arteries using TTE with the transmural extent of infarction (TEI) and infarct size, which were classified using contrast-enhanced magnetic resonance imaging (CE-MRI), in patients with AMI. METHODS: The DDT of the culprit coronary artery was measured in 74 patients using TTE and CE-MRI 1 week after the onset of AMI. The TEI was graded based on the transmural extent of the hyper-enhanced tissue (grades 1-4). RESULTS: The assessable rate for the DDT was 95%; individual rates were 100% for the left anterior descending coronary artery, 90% for the left circumflex artery, and 93% for the right coronary artery. The DDT decreased gradually as the TEI grade progressed (P = .021). Infarct size was significantly correlated with the DDT (r = -0.51, P < .0001). Univariate analysis revealed that the left ventricular (LV) end-systolic volume, LV ejection fraction, and DDT were significantly associated with TEI grade 4. After adjustment via multiple logistic regression analysis, the DDT was independently remained. With a cutoff value of 950ms, as determined by the ROC curve, DDT could detect TEI grade 4 with 81.1% sensitivity and 80.1% specificity. CONCLUSION: The DDT of three major coronary arteries measured by TTE 1 week after the onset of AMI can assess the extent of myocardial damage, which is determined by CE-MRI.

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.

Increased plaque rupture forms peak incidence of acute myocardial infarction in winter.

BACKGROUND: It has been widely documented that circannual variation has an impact on the incidence and prognosis of cardiovascular diseases. It is unclear why cold ambient temperature increase the incidence of acute myocardial infarction (AMI). We investigated the relationship between the ambient temperature at the onset of AMI, the morphology of the culprit lesion in patients with AMI. METHODS: We investigated 202 consecutive patients with AMI who underwent optical coherence tomography (OCT). The participants were divided into lower (n = 100) and higher (n = 102) temperature groups based on the ambient temperature. The culprit lesion morphology was compared between the two groups. RESULTS: The median temperature at the onset of AMI was 16.6 °C. The prevalence of plaque ruptures was higher at lower temperatures (lower 66% vs. higher 45%, p = .003), whereas OCT-erosion was more frequent in the higher temperature group (lower 13% vs. higher 26%, p = .021). The lower temperature group showed more cholesterol crystals (lower 71% vs. higher 54%, p = .014). CONCLUSION: The peak incidence of AMI in the winter is formed by increased plaque rupture, suggesting environmental temperature has an influence on the pathogenesis of AMI.

Very late-phase vascular response after everolimus-eluting stent implantation assessed by optical coherence tomography.

Long-term safety of second generation drug-eluting stents (DES) has not yet been evaluated. We sought to evaluate the very late phase (> 3 years) vascular response after second generation everolimus-eluting stent (EES) as compared with first generation sirolimus-eluting stent (SES) by using optical coherence tomography (OCT). We examined the vascular response in 39 patients with a total of 55 DESs [31 EESs (mean 54 months after stenting) and 24 first generation SES (mean 66 months after stenting)] by OCT. The frequency of lesions with any malapposed stent struts (19% vs. 46%, p = 0.035) and evagination (6% vs. 42%, p = 0.002) was significantly lower. Segments with malapposed stent struts were significantly shorter (0.4 ± 0.9 mm vs. 1.9 ± 3.5 mm, p = 0.024), maximal malapposition area and malapposition volume were significantly smaller (0.26 ± 0.38 mm2 vs. 0.95 ± 1.54 mm2, p = 0.019, and 0.78 ± 1.35 mm3 vs. 6.22 ± 15.76 mm3, p = 0.016, respectively) in EES. Compared with first generation SES, second generation EES showed more favourable vascular responses at the very late phase.

Optical Coherence Tomography Comparison of Percutaneous Coronary Intervention Among Plaque Rupture, Erosion, and Calcified Nodule in Acute Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) is caused by coronary plaque rupture (PR), plaque erosion (PE), or calcified nodule (CN). We used optical coherence tomography (OCT) to compare stent expansion immediately after primary percutaneous coronary intervention (PCI) in patients with AMI caused by PR, PE, or CN.Methods and Results:In all, 288 AMI patients were assessed by OCT before and immediately after PCI, performed with OCT guidance according to OPINION criteria for stent sizing and optimization. The frequency of OCT-identified PR (OCT-PR), OCT-PE, and OCT-CN was 172 (60%), 82 (28%), and 34 (12%), respectively. Minimum stent area was smallest in the OCT-CN group, followed by the OCT-PE and OCT-PR groups (mean [±SD] 5.20±1.77, 5.44±1.78, and 6.44±2.2 mm2, respectively; P<0.001), as was the stent expansion index (76±13%, 86±14%, and 87±16%, respectively; P=0.001). The frequency of stent malapposition was highest in the OCT-CN group, followed by the OCT-PR and OCT-PE groups (71%, 38%, and 27%, respectively; P<0.001), as was the frequency of stent edge dissection in the proximal reference (44%, 23%, and 10%, respectively; P<0.001). The frequency of tissue protrusion was highest in the OCT-PR group, followed by the OCT-PE and OCT-CN groups (95%, 88%, and 85%, respectively; P=0.036). CONCLUSIONS: Stent expansion was smallest in the OCT-CN group, followed by the OCT-PR and OCT-PE groups. Plaque morphology in AMI culprit lesions may affect stent expansion immediately after primary PCI.