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.

Impact of transcatheter aortic valve implantation on coronary flow reserve by transthoracic Doppler echocardiography 1-year after the intervention in severe aortic stenosis patients

Background

Coronary flow reserve (CFR) which is one of indexes reflecting coronary microcirculation in patients without significant epicardial coronary lesions can be impaired in patients with severe aortic stenosis (AS). It has been shown that CFR is an independent predictor for future cardiovascular events in AS patients. Transcatheter aortic valve implantation (TAVI) has rapidly become widespread and is becoming the standard treatment for severe AS. This procedure may have a good effect on CFR due to reduction of severe afterload in patients with severe AS. Although the recent reports evaluated change in CFR immediately and 6 months after TAVI, it has not been evaluated whether impaired CFR improves 1-year after TAVI in AS patients with preserved left ventricular ejection fraction (LVEF).

Purpose

The purpose of the present study was to investigate whether impaired CFR improves 1-year after TAVI in severe AS patients with preserved LVEF.

Methods

The study population consists of consecutive 105 patients with severe AS undergoing TAVI. Exclusion criteria were atrial fibrillation, old myocardial infarction, history of coronary artery bypass grafting, significant lesions in the left anterior descending artery (LAD), moderate or severe mitral valve disease, history of valve replacement, LVEF &lt;50% and preoperative CFR &gt;2.2. CFR was obtained from coronary flow velocity by transthoracic echocardiography at rest and maximal hyperemia in LAD before, immediately and 1-year after TAVI. We compared CFR between before and after TAVI in the study patients who did not meet the exclusion criteria.

Results

After exclusion of 76 patients who met the exclusion criteria, the final study patients consist of 29 patients (8 male, 84.9±5.2 years). There was no significant difference in LVEF (61.3±3.4% vs 61.6±4.4%, P=0.667) and LV end-diastolic volume (LVEDVI; 58.2±9.2 mL/m2 vs 55.8±9.0 mL/m2, P=0.089) between before and immediately after TAVI. LVEF (61.0±2.8%, P=0.721) and LVEDVI (58.0±9.1 mL/m2, P=0.949) 1-year after TAVI were similar to those before TAVI. There was no significant difference in coronary flow velocity at rest between before and immediately after TAVI (27.4±8.9 vs 24.4±7.0 cm/s, P=0.051) and between before and 1-year after TAVI (25.9±8.3 cm/s, P=0.396). Coronary flow velocity at maximal hyperemia 1-year after TAVI significantly increased compared with that before TAVI (from 48.8±13.9 to 67.9±21.0 cm/s, P&lt;0.001) while there was no significant difference between before and immediately after TAVI (52.0±12.0 cm/s, P=0.186). Impaired CFR before TAVI (1.82±0.28) increased immediately (2.03±0.39, P=0.009) and 1-year after TAVI (2.69±0.57, P&lt;0.001).

Conclusions

The present results suggest that impaired CFR in patients with preserved LVEF improves 1-year after TAVI. TAVI may have a good effect on CFR in severe AS patients with preserved LVEF.

Funding Acknowledgement

Type of funding sources: None.

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 (SVI_Doppler) or biplane Simpson (SVI_Biplane) method. AVAI_Dopplerand AVAI_Biplaneoften show discrepancy due to differences between SVI_Dopplerand SVI_Biplane. 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 (AVA_Doppler<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. SVI_Dopplerwas significantly larger than SVI_Biplane(49±11 vs. 39±11 mL/m², P<0.01) and AVAI_Dopplerwas larger than AVAI_Biplane(0.51±0.15 vs. 0.41±0.14 cm²/m², P<0.01). An increase in (AVAI_Doppler- AVAI_Biplane) 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 AVAI_Doppleror AVAI_Biplaneenabled 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.

Lesion characteristics and prognosis of acute coronary syndrome without angiographically significant coronary artery stenosis

AIMS

While patients with acute coronary syndrome (ACS) presenting with non-obstructive coronary artery disease (CAD) are at high risk for cardiovascular mortality and morbidity, detailed lesion characteristics are unclear. The aim of this study was to investigate the lesion characteristics and prognosis of ACS with non-obstructive CAD.

METHODS AND RESULTS

This study consisted of 82 consecutive ACS patients without obstructive CAD who underwent optical coherence tomography (OCT). Based on the presence of high-risk lesions (HL) in the culprit artery, we classified the patients into two groups: HL group and non-high-risk lesions (NHL) group. A systematic clinical follow-up was performed at our outpatient clinic for up to 24 months. Our endpoint was recurrence of ACS with obstructive CAD. OCT revealed that 42 (51.2%) of 82 patients had hidden HL in the culprit artery, including ruptured plaque (15.9%), calcified nodule (11.0%), spontaneous coronary artery dissection (8.5%), lone thrombus (8.5%), thin-cap fibroatheroma (6.1%), and plaque erosion (1.2%). During angiography, 5 (11.9%) HL patients complained of chest pain without ST elevation. Patients in the HL group had poorer prognoses than those in the other groups (P = 0.040).

CONCLUSION

Hidden high-risk lesions accompany ACS patients without obstructive CAD, resulting in poorer outcomes. Vascular injury itself might provoke acute chest pain.

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.

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.

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.

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.

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.

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 (maxLCBI_4mm) 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 maxLCBI_4mm 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 maxLCBI_4mm 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 maxLCBI_4mm 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 maxLCBI_4mm, NIRS-IVUS can accurately differentiate PR, PE, and CN.

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.

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.

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.

Extent of the difference between microcatheter and pressure wire-derived fractional flow reserve and its relation to optical coherence tomography-derived parameters

Background

Although previous studies demonstrated that microcatheter-derived fractional flow reserve (mc-FFR) tends to overestimate lesion severity compared to pressure wire-derived FFR (pw-FFR), the clinical utility of mc-FFR remains obscure. The extent of differences between the two FFR systems and its relation to a lesion-specific parameter remain unknown. In this study, we sought to compare mc-FFR with pw-FFR and determine the lower and upper mc-FFR cut-offs predicting ischemic and non-ischemic stenosis, using an ischemic and a clinical FFR threshold of 0.75 and 0.80 as references, respectively. We further explored optical coherence tomography (OCT) parameters influencing the difference in FFR between the two systems.

Methods and results

In this study, 44 target vessels with intermediate de novo coronary artery lesion in 36 patients with stable ischemic heart disease were evaluated with mc-FFR, pw-FFR and OCT. Bland-Altman plots for mc-FFR versus pw-FFR showed a bias of −0.04 for lower mc-FFR values compared to pw-FFR values. The mc-FFR cut-off values of 0.73 and 0.79 corresponded to the 0.75 ischemic pw-FFR and 0.80 clinical pw-FFR thresholds with high predictive values, respectively. The differences in the two FFR measurements (pw-FFR minus mc-FFR) were negatively correlated with OCT-derived minimum lumen area (MLA) (R = −0.359, p = 0.011). The OCT-derived MLA of 1.36 mm² was a cut-off value for predicting the clinically significant difference between the two FFR measurements defined as >0.03.

Conclusion

Mc-FFR is clinically useful when the specific cut-offs are applied. An OCT-derived MLA accounts for the clinically significant difference in FFR between the two systems.

P914 Changes of echocardiographic parameters in primary mitral regurgitation and determinants of symptom: an assessment from the Asian valve registry data

[Background]Clinicians often have a difficulty in determining the presence of mitral regurgitation (MR)-relatedsymptoms because of subjectivity.However, there are few actual measurement data for echocardiographic left ventricular (LV) and left atrial (LA) size related to the severity of MR and the relationship between MR-related symptoms and these echocardiographic parameters.

[Purpose] The purpose of this study was to clarify actual values for echocardiographic parameters related to severity of MR and determinant factors of MR-related symptoms.

[Methods] Among patients enrolled in the Asian Valve Registry, we investigated 778 consecutive patients with primary MR showing sinus rhythm. Symptoms were determined by NYHA (≤ II or ≥ III).

[Results]MR severity was mild in 106, moderate in 285, and severe in 387 patients. LA volume index, LV end-diastolic diameter, and LV mass index increased with increasing MR grade [LA volume index: 47.9 (mild), 56.2 (moderate), and 64.9 ml/m2(severe) (p &lt; 0.001), LV end-diastolic diameter: 51.2, 54.5, 58.1 mm (p &lt; 0.001), and LV mass index: 101, 109, 123 g/m2(p &lt; 0.001)]. Regarding moderate and severe MR, 70 patients (10.4%) were symptomatic. Table shows multivariable analysis for being symptomatic in moderate and severe MR patients. LV mass index (p = 0.040), ejection fraction (p &lt; 0.001), female gender (p = 0.004), and heart rate (p = 0.007) were independent factors for MR-related symptoms.

[Conclusions] LV and LA parameters on echocardiography worsened as MR severity progressed. Larger LV mass index and lower ejection fraction were independent determinant factors for MR-related symptoms. We should also pay attention to LV hypertrophy in patients with primary MR.

Determinant factors for mitral regurgita Model 1 Model 2 OR (95% CI) P-value OR (95% CI) P-value Age, per 1-y increment 1.03 (1.00-1.05) 0.035 1.02 (0.99-1.05) 0.053 Sex (female) 2.23 (1.20-4.16) 0.011 2.28 (1.31-3.98) 0.004 Hear rate, per 1 bpm increment 1.03 (1.00-1.05) 0.025 1.03 (1.01-1.05) 0.007 LVDs index, per 1 mm increment 0.99 (0.90-1.09) 0.90 EF, per 1% increment 0.95 (0.92-0.99) 0.019 0.96 (0.93-0.98) &lt;0.001 LV mass index, per 10 g/m2increment 1.12 (1.01-1.25) 0.033 1.09 (1.005-1.18) 0.040 LA volume index, per 10 mL/m2increment 0.96 (0.90-1.03) 0.23 E wave, per 1cm/s increment 1.81 (0.70-4.66) 0.23 TR pressure gradient &gt;40 mmHg 2.11 (0.97-4.57) 0.057 Hypertention 1.40 (0.75-2.63) 0.29

P1518 Relationship between post-operative asymptomatic status and reverse remodeling of large left atrium in patients with aortic stenosis who underwent aortic valve replacement

Introduction

Recently, we have reported that large left atrial volume (minimum left atrial volume index : LAVImin ≥30ml/m²) at end-diastole determined by direct exposure of left ventricular (LV) end-diastolic pressure can predict post-operative symptomatic status after aortic valve replacement (AVR) in aortic stenosis (AS) patients with high sensitivity and modest specificity. Reverse remodeling of large LAVImin after AVR may contribute to false positive for the prediction of post-operative symptomatic status in patients with AS.

Purpose

The purpose of this study was to evaluate relationship between post-operative symptomatic status and reverse remodeling of large LAVImin in patients with AS who underwent AVR.

Methods

The study population consisted of 75 patients with AS who underwent AVR and were followed up for 600 days after AVR, after the exclusion of the followings; atrial fibrillation, significant coronary artery disease, significant mitral valve disease, pacemaker rhythm, and inadequate echocardiographic images. We measured LAVImin by biplane Simpson"s method before and after AVR. Preoperative large LAVImin (≥30ml/m²) according to the previous study was observed in 32 (43%) of 75 patients. We divided these 32 patients into two groups according to the post-operative symptomatic status during the follow-up period.

Results

There was no significant difference in pre-operative LAVImin between patients with and without post-operative symptom (46.5 ± 13.4 vs 40.4 ± 8.6 ml/m²). On the other hand, post-operative LAVImin in patients without post-operative symptom was significantly smaller than that in patients with post-operative symptom (31.5 ± 8.6 vs 54.8 ± 14.0 ml/m², p &lt; 0.01). While significant regression in LAVImin after AVR was observed in patients without post-operative symptom (40.4 ± 8.6 to 31.5 ± 8.6 ml/m², p &lt; 0.05), no regression in LAVImin after AVR was observed in patients with post-operative symptom (46.5 ± 13.4 to 54.8 ± 14.0 ml/m²).

Conclusions

Reverse remodeling of large LAVmin in patients with AS who underwent AVR was observed in post-operative asymptomatic group, but not in symptomatic group. These results suggest that reverse remodeling of large LAVImin after AVR could contribute to the post-operative asymptomatic status in patients with AS who underwent AVR.

P91 Prognostic value of tissue-tracking mitral annular displacement by speckle-tracking echocardiography in asymptomatic patients with aortic stenosis with preserved left ventricular ejection fraction

Background

  Management of asymptomatic severe aortic stenosis (AS) patients with preserved left ventricular (LV) ejection fraction (EF) remains controversial. Recent studies using have shown that decreased LV longitudinal deformation assessed by global longitudinal strain analysis can predict adverse cardiac events in AS patients with preserved EF. Tissue-tracking mitral annular displacement (TMAD) by speckle-tracking echocardiography provides rapid and simple assessment of LV longitudinal deformation even when the acoustic window is poor (Fig.1).

Purpose

 The purpose of this study was to examine the value of TMAD to predict occurrence of the cardiac events in asymptomatic severe AS patients with preserved EF.

Methods

  We studied 103 patients with severe AS and preserved EF [aortic velocity &gt;4m/s or aortic valve area (AVA) &lt;1.0 cm2, EF &gt;50%]in whom TMAD was measured, and a total of 44 patients were included in the final data setaccording to the exclusion criteria. 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 (Fig.1). We investigated the association between %TMAD and the cardiac events including implementation of hospitalization due to heart failure, decreased EF (&lt; 50%), aortic valve replacement or transcatheter aortic valve implantation due to appearance of symptoms and cardiac death, 

Results

 In all the final study patients, %TMAD was successfully and quickly (within 10 seconds) evaluated. During a follow-up, the cardiac events developed in 16 (36%) of 44 patients. Tableshows echocardiographic parameters in patients with and without the cardiac events. %TMAD was significantly impaired in patients with the cardiac events compared with those without the cardiac events (9.6 ± 0.6 vs 12.1 ± 0.4%, p= 0.002). The other parameters were not involved in the event occurrence; age, LV mass index, EF, aortic velocity, AVA, tricuspid regurgitation pressure gradient (TR-PG), early diastolic /atrial filling velocity (E/A), early diastolic velocity of the mitral valve annulus (e’) and E/e’. In multiple variable analysis, %TMAD was an independentpredictor of the cardiac events (HR; 12.1, p= 0.001). ROC analysis revealed that the area under the curve of %TMAD was 0.81 for the cardiac events. Kaplan-Meier analysis showed %TMAD (cut-off: 11.9) provides a significant difference in the cardiac event (Fig. 2). Conclusions.  The present results suggests that TMAD easily and rapidly estimated by speckle-tracking echocardiography can be used as a simple method to predict occurrence of the cardiac events in asymptomatic severe AS patients with preserved EF.

Abstract P91 Figure 1,2 and Table

P2700Impact of instantaneous wave-free ratio on graft failure after coronary artery bypass graft surgery

Background

It has been reported that preoperative fractional flow reserve (FFR) is associated with graft patency after coronary artery bypass graft (CABG) and the patency is excellent when a bypass graft is anastomosed on a vessel with positive FFR. However, the association with graft patency has not yet been investigated in its novel counterpart, instantaneous wave-free ratio (iFR), and iFR sometimes contradicts FFR results.

Purpose

The purpose of this study is to assess an impact of preoperative iFR on a graft failure after CABG in patients with coronary arteries showing positive FFR (≤0.80).

Methods

We retrospectively identified patients who had undergone preoperative coronary angiography in conjunction with resting and hyperemic intra-coronary pressure measurements, CABG, and graft evaluation by coronary computed tomography angiography. After excluding vessels with negative FFR (>0.80), vessels were divided into two groups: negative iFR group (iFR >0.89) and positive iFR group (iFR ≤0.89). The rate of graft failure within 1 year after CABG was compared between the two groups.

Results

We analyzed 131 vessels in 89 patients (35 vessels in the negative iFR group and 96 vessels in the positive iFR group). The negative iFR group showed significantly higher iFR (0.92±0.02 vs. 0.74±0.13, P<0.0001) and FFR (0.72±0.06 vs. 0.63±0.09, P<0.0001) than the positive iFR group, although percent diameter stenosis (%DS) was comparable (57±10 vs. 56±9, P=0.47). The graft failure significantly often occurred in the negative iFR group than in the positive iFR group (28.6% vs. 8.3%, P=0.0029). In order to reduce the imbalance in the baseline characteristics except for iFR, 70 vessels were selected by using propensity score matching (n=35 in each group). The propensity score matched vessels also demonstrated significantly higher rate of graft failure in the negative iFR group than in the positive iFR group (28.6% vs. 5.7%, p=0.026) despite much more balanced FFR (0.72±0.06 vs. 0.69±0.07, p=0.02) and %DS (57±10 vs. 57±9, p=1.000).

Conclusions

Even when FFR is positive, the graft failure is likely to occur when a bypass graft is anastomosed on a vessel with negative iFR compared to a vessel with positive iFR.

Acknowledgement/Funding

None

P3387Cholesterol crystals in superficial plaque layer detected by optical coherence tomography as a new morphological feature for plaque rupture

Background

While plaque rupture (PR) is the leading cause of acute myocardial infarction (AMI), other etiologies are also involved in the onset of AMI. Cholesterol crystals (CCs) are usually present abundantly in atherosclerotic plaques, especially in the culprit site of AMI. However, the relationship between in vivo CCs and PR is unclear. Optical coherence tomography (OCT) is a high-resolution imaging technique that allows for the in vivo identification of various plaque characteristics including PR and CCs.

Purpose

The aim of this study was to investigate prevalence and distribution of CCs between patients with AMI with PR, AMI without PR, and SAP.

Method

This study consisted of 146 patients with coronary artery disease (AMI with PR; n=64, AMI without PR; n=41, and SAP; n=41) who underwent OCT prior to percutaneous coronary intervention. Plaque characteristics in OCT images were assessed according to the consensus document. We classified the distribution of CCs as follows; superficial type CCs were defined by any of the CCs invading the fibrous cap and remaining CCs as deep type CCs.

Result

There was no statistical difference in clinical characteristics among the three groups. The % diameter stenosis was significantly smaller in the SAP group than others (AMI with PR 91±12% vs. AMI without PR 86±13% vs. SAP 65±9%, p<0.001). The prevalence of CCs was significantly higher in the AMI with PR group than others (AMI with PR 78% vs. AMI without PR 41% vs. SAP 39%, p<0.001). The prevalence of superficial type CCs was significantly different among the groups (AMI with PR 72% vs. AMI without PR 24% vs. SAP 7%, p<0.001). Multivariable logistic analysis demonstrated that lipid plaque (OR 84.5, 95% CI [6.30–11332.33], p<0.001) and superficial type CC (OR 9.5, 95% CI [2.61–34.89], p<0.001) were independent predictors of PR.

Conclusion

Plaque with CCs invading the fibrous cap is frequently associated with PR in patients with AMI, suggesting. In vivo CC detection is a new morphological feature for plaque rupture.

Acknowledgement/Funding

This study was supported by a grant from JSPS KAKENHI (17K09557).

P3365Relationship between early diastolic intra-ventricular pressure gradient shortly after aortic valve closure estimated by vector flow mapping and left ventricular diastolic untwisting rate in humans

Background

Early diastolic suction is an important determinant of early diastolic function. Previous studies using color Doppler M-mode and speckle-tracking echocardiography have shown left ventricular (LV) early diastolic LV untwisting rate is directly related to LV intra-ventricular pressure gradient (IVPG) between LV base and apex during early diastole. Recent introduction of vector flow mapping (VFM) using combination of color Doppler and speckle-tracking echocardiography provides noninvasive and feasible assessment of early diastolic IVPG shortly after aortic valve closure including isovolmic relaxation period (ED-IVPG) in humans. However, relationship between VFM–derived ED-IVPG and early diastolic LV untwisting rate has not been well investigated.

Purpose

The purpose of this study was to examine relationship between ED-IVPG estimated by VFM and LV untwisting rate by speckle-tracking echocardiography.

Methods

The study population consists of 66 patients without segmental wall motion abnormality, significant valvular diseases, and atrial fibrillation who underwent echocardiography for evaluation of LV function (age: 60±15 years, LVEF: 49±16%). From the apical long-axis views by color Doppler echocardiography, we analyzed peak ED-IVPG between LV base and apex just after aortic valve closure (figure) using commercially available VFM analysis software (DAS-RS1, Hitachi). We assessed peak early diastolic LV untwisting rate and LV torsion from LV basal and apical short-axis view by speckle-tracking echocardiography. We evaluated correlation between ED-IVPG and LV untwisting rate. We also evaluated correlation between ED-IVPG and peak systolic LV torsion, LV end-diastolic (EDV) and end-systolic volumes (ESV), ejection fraction (EF), early diastolic velocity (E) of LV inflow, average early diastolic velocity (e') of mitral annulus, and average E/e'.

Results

In all the study patients, ED-IVPG was successfully and quickly evaluated. 1) ED-IVPG correlated well with peak LV untwisting rate (r=0.64, p<0.0001). 2) ED-IVPG significantly correlated with LV torsion, LVEDV, LVESV, and LVEF (r=0.47, r=−0.48, r=−0.46, and r=0.48, respectively, p<0.001). 3) There were no significant correlations between ED-IVPG and other indexes including E, average e', and average E/e'. According to receiver operating characteristic analysis, the best cut-off value of ED-IVPG for determining impaired LV untwisting rate (<80 degrees/s) was found at 0.42 mmHg (sensitivity 81%, specificity 76%, and area under the curve 0.86)

ED-IVPG measurement by VFM

Conclusions

The present results showed that noninvasive VFM-derived peak ED-IVPG shortly after aortic valve closure is related to early diastolic peak LV untwisting rate. ED-IVPG easily and quickly estimated by VFM may be used as an additional index for LV diastolic function.

P2453Value of pre-operative left atrial minimum volume as a surrogate for post-operative symptoms in patients with aortic stenosis who underwent aortic valve replacement

Background

Previous reports have shown that symptoms after aortic valve replacement (AVR) are not uncommon depending on severity of myocardial fibrosis in patients with severe aortic stenosis (AS). Pre-operative minimum left atrial volume (LAVmin) at end-diastole determined by direct exposure of left ventricular end-diastolic pressure may be used as a surrogate for post-operative symptoms in patients with severe AS undergoing AVR.

Purpose

The purpose of this study was to examine the value of pre-operative echocardiographic LAVmin index (LAVImin) to predict post-operative symptomatic status after AVR in patients with severe AS.

Methods

The study population consisted of 219 patients with severe AS who underwent AVR and were followed up for 1000 days after AVR. Pre-operative maximum LAV index (LAVImax), LAVImin, LA emptying fraction (LAEF), LV volume indexes, LV ejection fraction (LVEF) by biplane Simpson's method, aortic valve area index (AVAI), mean aortic valve pressure gradient (mAV-PG), E/A, mean E/e' from LV inflow and mitral annular velocity, and pulmonary artery systolic pressure (PASP) were evaluated by Doppler echocardiography.

Results

After exclusion of 136 patients who met the exclusion criteria (atrial fibrillation, significant coronary artery disease, significant mitral valve diseases, pacemaker rhythm, and inadequate echocardiographic images), the final study population consisted of 75 patients (75±7 years old, 46 female). During a follow-up, 19 patients (25%) complained post-operative symptoms. There were no significant differences in pre-operative serum hemoglobin, creatinine, BNP, chronic obstructive pulmonary disease, hypertension, diabetes, LV volume indexes, LVEF, AVA, mAV-PG between patients with and without post-operative symptoms. There were significant differences in pre-operative LAVImax, LAVImin, and LAEF between patients with and without post-operative symptoms. (60±15 vs 47±15 ml/m2, 45±15 vs 28±1 ml/m2, and 29±12 vs 42±11 ml/m2, respectively). E/A, mean E/e', and PASP in patients with symptoms were significantly greater compared with patients without symptoms (1.0±0.3 vs 0.7±0.2, 25±3 vs 18±2, 44±17 vs 32±9 mmHg, respectively). In the multivariate analysis, pre-operative LAVImin was the independent predictor of the post-operative symptomatic status after AVR (odds ratio: 1.11, 95% confidence interval: 1.04 - 1.18). Receiver operating characteristic analysis revealed that area under the curve (AUC) of LAVImin (cutoff: 30ml/m2) for post-operative symptoms was the largest (0.84) among the other echocardiographic parameters, and significantly larger than that of mean E/e' (0.67, *p<0.01) and LVEF (0.53, **p<0.05) (figure).

Figure 1. ROC analysis

Conclusions

The present results suggest that pre-operative echocardiographic LAVImin may be used as a surrogate for post-operative symptomatic status after AVR in patients with severe AS.

102Diagnosis of coronary plaque rupture, plaque erosion, and calcified nodule by using near-infrared spectroscopy intravascular ultrasound

Objectives

This study sought to investigate the ability of near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) to differentiate among plaque rupture (PR), plaque erosion (PE), and calcified nodule (CN) in acute myocardial infarction (AMI) using an optical coherence tomography (OCT) diagnosis as a reference standard.

Background

In vivo, precise differentiation among PR, PE and CN is a major challenge for intravascular imaging.

Methods

The study enrolled 156 AMI patients who had a de novo culprit lesion in a native coronary artery. The culprit lesions were assessed by both NIRS-IVUS and OCT.

Results

OCT identified 112 PR, 29 PE, and 15 CN. IVUS-detected plaque ulceration showed a high specificity (100%) to identify OCT-PR although the sensitivity (62%) was intermediate. IVUS-detected convex calcium showed a high sensitivity (93%) and specificity (100%) to identify OCT-CN. In NIRS, the maximum lipid core burden index in 4 mm (maxLCBI4mm) was greatest in OCT-PR (values are median [interquartile range]) (671 [530 to 853]), followed by OCT-CN (355 [303 to 432]) and OCT-PE (283 [89 to 357]) (p<0.001). MaxLCBI4mm of <422 was the best cut-off to discriminate OCT-PE from OCT-PR and OCT-CN. The NIRS-IVUS classification algorithm using plaque ulceration, convex calcium, and maxLCBI4mm <422 showed a sensitivity and specificity of 96% and 95% for identifying OCT-PR, 93% and 95% for OCT-PE, and 93% and 100% for OCT-CN, respectively.

NIRS-IVUS classification algorism

Conclusion

Lipid component assessed by NIRS-IVUS was different among OCT-PR, OCT-PE and OCT-CN. The NIRS-IVUS classification algorism was highly sensitive and specific for differentiating these unstable lesion types in AMI.

Acknowledgement/Funding

None

P4349Simple and rapid estimation of left ventricular longitudinal deformation by tissue-tracking mitral annular displacement in single apical view

Background

Noninvasive assessment of left ventricular (LV) deformation using global longitudinal strain (GLS) has prognostic value in patients with and without preserved ejection fraction (EF). Application of speckle-tracking technology to the mitral annulus provides rapid and easy assessment of displacement of septal and lateral mitral annulus and mid-point of mitral annular line in single apical view (TMAD) even in poor echo-image quality. TMAD may be used as a simple index of LV longitudinal deformation in patients with and without preserved EF (Figure).

Purpose

The purpose of this study was to examine whether TMAD can be used as a simple index of LV longitudinal deformation in patients with and without preserved EF.

Methods

The study population consists of 95 patients without segmental wall motion abnormality, significant valvular diseases, and atrial fibrillation in whom both TMAD and GLS measurements were applied by QLAB software (Philips). We estimated GLS from apical 4- and 2-chamber views and apical longitudinal views, and TMAD from apical 4-chamber view. TMAD was automatically and quickly evaluated as the base-to-apex displacement of septal (TMADsep), lateral (TMADlat), and mid-point of annular line (TMADmid) (Figure). The percentage of M-TMAD to LV length from the mid-point of mitral annuls to the apex at end-diastole (%TMADmid) was also calculated. We compared each TMAD values with GLS values by linear regression analysis, and evluated TMAD values by a receiver operating characteristic (ROC) analysis to detect impaired LV longitudinal deformation (|GLS|<12.0%).

Results

TMAD was successfully assessed in 94 of 95 patients (99%) while GLS was measured in 84 of 95 patients (87%, p=0.0082 vs TMAD). There were good correlations between each TMAD index and |GLS| (TMADsep:r=0.77, TMADlat:r=0.81, TMADmid:r=0.82, %TMADmid:r=0.87). According to ROC curve, the best cut-off values for TMADsep, TMADlat, TMADmid, and %TMADmid in determining LV longitudinal deformation were 6.8mm, 8.0mm, 7.8mm, and 9.5% respectively (Table).

Conclusions

The present results suggest that rapid and easy assessment of TMAD in single apical view may be used as a simple index of LV longitudinal deformation.

Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

BACKGROUND

Optical coherence tomography (OCT) requires intracoronary injection of contrast media to remove blood from the field of view during image acquisition. Contrast injection may cause a temporal increase in intracoronary pressure. The aim of this study was to compare the intracoronary pressure during contrast injection between OCT and coronary angiography.

METHODS

We measured intracoronary pressure by using a pressure guidewire during contrast injection for OCT and angiography in 30 coronary arteries (mean fractional flow reserve = 0.90 ± 0.03). Contrast media was injected into coronary artery through the guiding catheter by using a mechanical injector pump.

RESULTS

Intracoronary pressure before contrast injection was similar between OCT and angiography (systolic pressure: 123 ± 18 mmHg vs. 122 ± 19 mmHg, p = 0.863). Intracoronary pressure was increased due to contrast injection in both OCT (systolic pressure: 123 ± 18 mmHg to 132 ± 18 mmHg, p < 0.001) and angiography (systolic pressure: 122 ± 19 mmHg to 128 ± 19 mmHg, p < 0.001). The increase in intracoronary pressure was slightly greater in OCT compared with angiography (absolute increase of systolic pressure: 9 ± 2 mmHg vs. 6 ± 1 mmHg, p < 0.001; and relative increase of systolic pressure: 8 ± 2% vs. 5 ± 1%, p < 0.001). Intracoronary pressure during contrast injection was not significantly different between OCT and angiography (systolic pressure: 132 ± 18 mmHg vs. 128 ± 19 mmHg, p = 0.831).

CONCLUSIONS

Contrast injection for OCT induced significant but small increase in intracoronary pressure compared with that for angiography.

Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology

Optical coherence tomography (OCT) is a coronary artery imaging technique with high resolution. Second-generation frequency-domain OCT (FD-OCT) technology allows safer and faster clinical application compared with first-generation time-domain OCT (TD-OCT). Only limited validation studies compare FD-OCT with other modes of analysis: histology, which is the current gold standard, and intravascular ultrasound (IVUS). This study therefore aims to demonstrate the accuracy of FD-OCT images compared with IVUS and histology. FD-OCT and IVUS images were acquired from 203 segments from 31 coronary arteries obtained at autopsy from 20 cadavers. Of these, 30 randomly-selected pairs were used to create three classifications of plaque type based on morphological features in FD-OCT and IVUS compared with corresponding histopathology. The remaining 173 pairs were used to demonstrate the diagnostic accuracy for classification of coronary plaques by FD-OCT. Plaque type distributions were 27% fibroatheroma, 22% fibrocalcific plaque and 51% fibrous plaque. The diagnostic accuracies of FD-OCT for fibroatheroma, fibrocalcific plaque and fibrous plaque were 90, 95 and 93%, respectively. Those of IVUS were 81, 89 and 84%, respectively. FD-OCT achieved high diagnostic accuracy for the classification of coronary plaques comparable to TD-OCT. Physicians should consider the differences in the ability to classify plaque morphology of OCT of imaging devices when applying their use.

Value of tissue-tracking tricuspid annular plane by speckle-tracking echocardiography for the assessment of right ventricular systolic dysfunction

BACKGROUND

Assessment of right ventricular (RV) function remains challenging because of its complex geometry. Application of speckle-tracking echocardiography (STE) to the tricuspid annulus provides rapid and automated assessment of the midpoint of the tricuspid annular plane displacement (TAD). The aim of this study was to investigate the value of tissue-tracking TAD for the assessment of RV systolic dysfunction.

METHODS

We retrospectively studied 61 patients in whom RV ejection fraction (EF) measured by 3-dimensional echocardiography was performed. STE-derived displacement of the midpoint between the septal and lateral tricuspid annulus and its percentage of RV length at end-diastole (MTAD) were automatically assessed. We performed comparative analyses between the RVEF ≥45% group and the RVEF <45% group in each parameter for the assessment of RV systolic function.

RESULTS

MTAD was successfully assessed in 56 (91.2%). According to receiver operating characteristics analysis, RVEF <45% was best detected by MTAD <14.7% with area under curve (AUC) 0.97, sensitivity 93%, specificity 95%, followed by RV free wall longitudinal strain (AUC 0.86), RV fractional area change (AUC 0.84), tricuspid annular plane systolic excursion (AUC 0.79), and systolic peak velocity of tricuspid annulus (AUC 0.70), although there was no significant difference between MTAD and RV free wall strain (P = 0.14).

CONCLUSION

The present study showed that MTAD was simple index and useful for the assessment of RV systolic dysfunction.

Automated lipid-rich plaque detection with short wavelength infra-red OCT system

Aims

Vulnerable coronary plaque is characterized by a large lipid core. Although commercially-available optical coherence tomography (OCT) systems use near-infrared light at 1300 nm wavelength, lipid shows characteristic absorption at 1700 nm. Therefore, we developed a novel, short wavelength infra-red, spectroscopic, spectral-domain OCT. The aim of the present study is to evaluate the accuracy of short wavelength (1700 nm) infra-red optical coherence tomography (SWIR-OCT) for identification of lipid tissue within coronary plaques.

Methods and results

Twenty-three coronary arteries from 10 cadavers were imaged at physiological pressure with 2.7 Fr SWIR-OCT catheter. When a blood-free image was observed, the SWIR-OCT imaging core was withdrawn at a rate of 20 mm/s using an automatic pullback device. SWIR-OCT images were acquired at 94 frames/s and digitally archived. SWIR-OCT generated grey-scale cross sectional images and colour tissue maps of all of the plaque by using a lipid analysis algorithm. After SWIR-OCT imaging, the arteries were pressure-fixed, sliced by cryostat and stained with Oil Red O, and then corresponding histology was collected in matched images. Regions of interest, selected from histology, were 117 lipidic and 34 fibrotic/calcified regions. SWIR-OCT showed high sensitivity (89%) and specificity (92%) for identifying lipid tissue within coronary plaques. The positive predictive value and negative predictive value were 97% and 74%, respectively.

Conclusion

SWIR-OCT accurately identified lipid tissue in coronary autopsy specimens. This new technique may hold promise for identifying histopathological features of coronary plaque at risk for rupture.