Validation of dual atrioventricular nodal physiology in dual atrioventricular nodal non-reentrant tachycardia via adenosine triphosphate injection during atrial pacing: A novel insight into the role of leftward inferior extension.

INTRODUCTION: Dual atrioventricular nodal non-reentrant tachycardia (DAVNNT) is a rare and challenging-to-diagnose arrhythmia, without previous reports associating it with a leftward inferior extension (LIE). METHODS: Diagnosis was made using adenosine triphosphate (ATP) injection during atrial pacing in a suspected DAVNNT patient. RESULTS: Ablation of the rightward inferior extension was unsuccessful in eliminating DAVNNT; however, subsequent ablation of the LIE successfully eradicated the arrhythmia. CONCLUSION: This unique case, marked by the first instance of DAVNNT caused by LIE, diagnosed through ATP injection, underscores the utility of this diagnostic approach and broadens the spectrum of our understanding and management of this condition.

Level of Vascular Inflammation Is Higher in Acute Coronary Syndromes Compared with Chronic Coronary Disease.

BACKGROUND: Vascular inflammation has been recognized as one of the key factors in the pathogenesis of acute coronary syndromes (ACS). Pericoronary adipose tissue (PCAT) attenuation by computed tomography angiography has emerged as a marker specific for coronary artery inflammation. We examined the relationship between clinical presentation and coronary artery inflammation assessed by PCAT attenuation and coronary plaque characteristics. METHODS: Patients with ACS or stable angina pectoris (SAP) who underwent preintervention coronary computed tomography angiography and optical coherence tomography were enrolled. PCAT attenuation was measured around the culprit lesion and in the proximal 40 mm of all coronary arteries. PCAT attenuation and optical coherence tomography findings were compared between patients with ACS versus SAP. RESULTS: Among 471 patients (ACS: 198, SAP: 273), PCAT attenuation was higher in ACS patients than in SAP patients both at the culprit plaque level (-67.5±9.6 Hounsfield unit [HU] versus -71.5±11.0 HU, P<0.001) and at the culprit vessel level (-68.3±7.7 HU versus -71.1±7.9 HU, P<0.001). The mean PCAT attenuation of all 3 coronary arteries was also significantly higher in ACS patients than in SAP patients (-68.8±6.3 HU versus -70.5±7.1 HU, P=0.007). After adjusting patient characteristics, not only thin-cap fibroatheroma (OR: 3.41; 95% CI: 1.89-6.17) and macrophages (OR: 3.32; 95% CI: 1.76-6.26) but also PCAT attenuation around the culprit plaque (OR: 1.03; 95% CI: 1.00-1.05) was associated with the clinical presentation of ACS. CONCLUSIONS: PCAT attenuation at culprit plaque, culprit vessel, and pan-coronary levels was higher in ACS patients than in SAP patients. Vascular inflammation appears to play a crucial role in the development of ACS. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04523194.

Prognostic Value of Coronary Sinus Flow Quantification by Cardiac Magnetic Resonance Imaging in Patients With Acute Myocardial Infarction.

Background This study aimed to evaluate the prognostic value of hyperemic coronary sinus flow (h-CSF) and global coronary flow reserve (g-CFR) obtained by phase-contrast cine-magnetic resonance imaging in patients with acute myocardial infarction (MI). Methods and Results This retrospective study analyzed patients with acute MI (n=523) who underwent primary (ST-segment-elevation MI) or urgent (non-ST-segment-elevation MI) percutaneous coronary intervention. Absolute coronary sinus blood flow (CSF) at rest and during vasodilator stress hyperemia was quantified at 30 days (24-36 days) after the index infarct-related lesion percutaneous coronary intervention and revascularization of functionally significant non-infarct-related lesions. We used Cox proportional hazards regression modeling to examine the association between h-CSF, g-CFR, and major adverse cardiac events defined as all-cause death, nonfatal MI, hospitalization for congestive heart failure, and stroke. Finally, 325 patients with ST-segment-elevation MI (62.1%) and 198 patients with non-ST-segment-elevation MI (37.9%) were studied over a median follow-up of 2.5 years. The rest CSF, h-CSF, and g-CFR were 0.94 (0.68-1.26) mL/min per g, 2.05 (1.42-2.73) mL/min per g, and 2.17 (1.54-3.03), respectively. Major adverse cardiac events occurred in 62 patients, and Cox proportional hazards analysis showed that h-CSF and g-CFR were independent predictors of major adverse cardiac events (h-CSF: hazard ratio [HR], 0.64; 95% CI, 0.47-0.88; P=0.005; g-CFR: HR, 0.62; 95% CI, 0.47-0.82; P=0.001). When stratified by h-CSF and g-CFR, cardiac event-free survival was the worst in patients with concordantly impaired h-CSF (<1.6 mL/min per g) and g-CFR (<1.7) (P<0.001). Conclusions Global coronary sinus flow quantification using phase-contrast cine-magnetic resonance imaging provided significant prognostic information independent of infarction size and conventional risk factors in patients with acute MI undergoing revascularization.

Plaque Rupture, Compared With Plaque Erosion, Is Associated With a Higher Level of Pancoronary Inflammation.

OBJECTIVES: The aim of this study was to compare the level of coronary inflammation between plaque rupture and plaque erosion using pericoronary adipose tissue (PCAT) attenuation. BACKGROUND: Vascular inflammation plays a key role in plaque rupture, while the role of inflammation in plaque erosion remains less well defined. PCAT attenuation determined using computed tomography has emerged as a marker specific for coronary artery inflammation. METHODS: Patients with non-ST-segment elevation acute coronary syndromes who underwent preintervention coronary computed tomographic angiography and optical coherence tomographic culprit lesion imaging were enrolled. PCAT attenuation was measured around the culprit lesion and in the proximal 40 mm of all coronary arteries. RESULTS: Among 198 patients, plaque rupture was the underlying mechanism in 107 (54.0%) and plaque erosion in 91 (46.0%). Plaque rupture had higher PCAT attenuation than plaque erosion both at the culprit plaque level (-65.8 ± 7.5 HU vs -69.5 ± 11.4 HU; P = 0.010) and at the culprit vessel level (-67.1 ± 7.1 HU vs -69.6 ± 8.2 HU; P = 0.024). The mean PCAT attenuation of all 3 coronary arteries was also significantly higher in patients with plaque rupture than in plaque erosion, indicating a higher level of inflammation (-67.9 ± 5.7 HU vs -69.9 ± 6.8 HU; P = 0.030). In multivariable analysis, plaque rupture was significantly associated with high PCAT attenuation. CONCLUSIONS: PCAT attenuation in culprit plaque, culprit vessel, and all 3 coronary arteries was higher in plaque rupture than in plaque erosion. The results suggest that pancoronary inflammation plays a more significant role in plaque rupture than in plaque erosion. (Massachusetts General Hospital and Tsuchiura Kyodo General Hospital Coronary Imaging Collaboration; NCT04523194).

Effect of percutaneous coronary intervention on global hemodynamics and the prevalence of residual microvascular dysfunction.

OBJECTIVES: We aimed to examine the changes in hyperemic coronary sinus flow (CSF) and global coronary flow reserve (g-CFR) after percutaneous coronary intervention (PCI) and investigate the predictors to improve these metrics and the prevalence of residual coronary microvascular dysfunction (CMD). METHODS: This prospective, single-center study included 118 patients with stable coronary artery disease undergoing PCI for a single proximal lesion. Phase-contrast cine-cardiac magnetic resonance (PC-CMR) was used to assess hyperemic CSF (HCSF) and g-CFR, before and after PCI. Residual CMD was defined as concordantly impaired post-PCI HCSF (<2.3 ml/min/g) and g-CFR (<2.0). RESULTS: HCSF significantly increased, although 38 (32.2%) patients showed a decrease. There was no significant change in g-CFR despite fractional flow reserve (FFR) improvement in all target territories. Concordantly increased HCSF and g-CFR were effectively discriminated by adding PC-CMR-derived information to pre-PCI FFR. Residual CMD was observed in 30 (25.4%) patients and was associated with pre-PCI renal dysfunction and lower pre-PCI rest and hyperemic CSF, but not with pre-PCI regional physiological indices. CONCLUSIONS: FFR-guided PCI was associated with increased HCSF, but not with increased g-CFR. After uncomplicated PCI, one-quarter of patients showed residual CMD. Our approach may help identify patients who may benefit from increased coronary perfusion or show residual CMD.

Physiological significance of pericoronary inflammation in epicardial functional stenosis and global coronary flow reserve.

Both fractional flow reserve (FFR) and global coronary flow reserve (g-CFR) provide prognostic information in patients with stable coronary artery disease (CAD). Inflammation plays a vital role in impaired endothelial dysfunction and atherosclerotic progression, potentially predicting cardiovascular mortality. This study aimed to evaluate the physiological significance of pericoronary adipose tissue inflammation assessed by CT attenuation (PCATA) in epicardial functional stenosis severity and g-CFR in patients with CAD. A total of 131 CAD patients with a single de novo epicardial coronary stenosis who underwent coronary CT-angiography (CCTA), phase-contrast cine-magnetic resonance imaging (PC-CMR) and FFR measurement were studied. PCATA was assessed using the mean CT attenuation value. G-CFR was obtained by quantifying absolute coronary sinus flow (ml/min/g) by PC-CMR at rest and during maximum hyperemia. Median FFR, g-CFR, and PCATA values were 0.75, 2.59, and - 71.3, respectively. Serum creatinine, NT-proBNP, left ventricular end-diastolic volume, and PCATA were independently associated with g-CFR. PCATA showed a significant incremental predictive efficacy for impaired g-CFR (< 2.0) when added to the clinical risk model. PCATA was significantly associated with g-CFR, independent of FFR. Our results suggest the pathophysiological mechanisms linking perivascular inflammation with g-CFR in CAD patients.

Early effect of percutaneous coronary intervention of non-left anterior descending artery on coronary flow velocity reserve of left anterior descending artery assessed by transthoracic Doppler echocardiography.

BACKGROUND: Limited data are available regarding the influence of percutaneous coronary intervention (PCI) of non-totally occluded lesions (non-CTO) on the coronary flow of non-target vessels. We sought to investigate the short-term impact of the non-left anterior descending artery (non-LAD) PCI on the coronary flow physiology of LAD using transthoracic Doppler echocardiography (TDE). METHODS AND RESULTS: We consecutively studied 50 patients who underwent successful PCI of non-LAD and non-CTO lesions and a coronary flow velocity assessment of LAD at rest and maximal hyperemia before and at 2 days after the procedure by TDE. Coronary flow velocity reserve (CFVR) was calculated as the ratio of hyperemic to resting diastolic peak velocity (hDPV/bDPV). We evaluated the changes in LAD coronary flow characteristics after PCI of non-LAD and explored the determinants of the change in LAD-CFVR. The median fractional flow reserve (FFR) of the culprit lesion and the LAD quantitative flow ratio (QFR) were 0.67 and 0.88, respectively. After non-LAD PCI, LAD-CFVR was decreased in 33 patients (66.0%). LAD-CFVR significantly decreased (pre-PCI: 2.41, post-PCI: 2.03, p = 0.001) due to a significant decrease in LAD-hDPV (P = 0.007). The prevalence of impaired LAD-CFVR (≤2.0) significantly increased (pre: 30%, post: 48%, P = 0.027). Multivariable linear regression analysis showed that pre-PCI LAD-CFVR was independent predictor of the change in LAD-CFVR after PCI. CONCLUSIONS: LAD-CFVR significantly decreased after successful non-LAD PCI due to the postprocedural reduction of coronary flow assessed by LAD-hDPV.

Low-molecular-weight dextran for optical coherence tomography may not be protective against kidney injury in patients with renal insufficiency.

BACKGROUND: Low-molecular-weight dextran (LMWD) is considered a safe alternative to contrast media for blood displacement during optical coherence tomography (OCT) imaging. AIM: To investigate whether the use of LMWD for OCT is protective against kidney injury in patients with advanced renal insufficiency. METHODS: In this retrospective cohort study, we identified 421 patients with advanced renal insufficiency (estimated glomerular filtration rate < 45 mL/min/1.73 m2) who underwent coronary angiography or percutaneous coronary intervention; 79 patients who used additional LMWD for OCT imaging (LMWD group) and 342 patients who used contrast medium exclusively (control group). We evaluated the differences between these two groups and performed a propensity score-matched subgroup comparison. RESULTS: The median total volume of contrast medium was 133.0 mL in the control group vs 140.0 mL in the LMWD group. Although baseline renal function was not statistically different between these two groups, the LMWD group demonstrated a strong trend toward the progression of renal insufficiency as indicated by the greater change in serum creatinine level during the 1-year follow-up compared with the control group. Patients in the LMWD group experienced worsening renal function more frequently than patients in the control group. Propensity score matching adjusted for total contrast media volume consistently indicated a trend toward worsening renal function in the LMWD group at the 1-year follow-up. Delta serum creatinine at 1-year follow-up was significantly greater in the LMWD group than that in the control group [0.06 (-0.06, 0.29) vs -0.04 (-0.23, 0.08) mg/dL, P = 0.001], despite using similar contrast volume. CONCLUSION: OCT using LMWD may not be protective against worsening renal function in patients with advanced renal insufficiency.

Vascular Responses to First-Generation Sirolimus-Eluting Stents and Bare-Metal Stents Beyond 10 Years.

Background: There are limited data regarding differences in vascular responses between first-generation sirolimus-eluting stents (1G-SES) and bare-metal stents (BMS) >10 years after implantation. Methods and Results: We retrospectively investigated 223 stents (105 1G-SES, 118 BMS) from 131 patients examined by optical coherence tomography (OCT) >10 years after implantation. OCT analysis included determining the presence or absence of a lipid-laden neointima, calcified neointima, macrophage accumulation, malapposition, and strut coverage. Neoatherosclerosis was defined as having lipid-laden neointima. OCT findings were compared between the 1G-SES and BMS groups, and the predictors of neoatherosclerosis were determined. The median stent age at the time of OCT examinations was 12.3 years (interquartile range 11.0-13.2 years). There were no significant differences in patient characteristics between the 1G-SES and BMS groups. On OCT analysis, there was no difference in the prevalence of neoatherosclerosis and calcification between 1G-SES and BMS. Multivariable logistic regression analysis revealed that stent size, stent length, and angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use were significant predictors of neoatherosclerosis. In addition, uncovered and malapposed struts were more prevalent with 1G-SES than BMS. Conclusions: After >10 years since implantation, the prevalence of neoatherosclerosis was no different between 1G-SES and BMS, whereas uncovered struts and malapposition were significantly more frequent with 1G-SESs.

Clinical Significance of Increased Computed Tomography Attenuation of Periaortic Adipose Tissue in Patients With Abdominal Aortic Aneurysms.

BACKGROUND: Recent imaging studies reported an association between vascular inflammation and progression of abdominal aortic aneurysm (AAA). This study investigated the clinical significance of periaortic adipose tissue inflammation derived from multidetector computed tomography angiography (MDCTA).Methods and Results:Patients with asymptomatic AAA (n=77) who underwent an index and >6 months follow-up MDCTA examinations were retrospectively investigated. MDCTA analysis included AAA diameter and the periaortic adipose tissue attenuation index (PAAI). The PAAI was defined as the mean CT attenuation value within a predefined range from -190 to -30 Hounsfield units of adipose tissue surrounding the AAA. The growth rate of the AAA was calculated as the change in diameter. AAA progression (AP) was defined as an AAA growth rate ≥5 mm/year. Univariate and multivariate logistic regression analysis were performed to determine the predictors of AP. AP was observed in 19 patients (24.7%), the median baseline AAA diameter was 38.9 mm (interquartile range [IQR] 32.7-42.9 mm), and the median growth rate was 3.1 mm/year (IQR 1.5-4.9 mm/year). Baseline AAA diameter (odds ratio [OR] 1.16; 95% confidence interval [CI] 1.05-1.28; P=0.001) and PAAI (OR 1.12; 95% CI 1.05-1.20; P=0.004) were independent predictors of AP. CONCLUSIONS: PAAI was an independent and significant predictor of AP, supporting the notion that local adipose tissue inflammation may contribute to aortic remodeling.

Effect of contrast medium versus low-molecular-weight dextran for intracoronary optical coherence tomography in renal insufficiency.

Low-molecular-weight dextran (LMWD) is considered a safe alternative to contrast media to displace blood during optical coherence tomography (OCT) imaging, but concerns remain. The purpose of this study was to investigate whether using LMWD for OCT protects against kidney injury in patients with renal insufficiency compared with contrast media. We retrospectively identified 474 patients with renal insufficiency (estimated glomerular filtration rate < 60 ml/min/1.73 m2) who underwent OCT during coronary angiography or percutaneous coronary intervention; 110 patients with LMWD plus contrast medium (LMWD group) and 364 patients with contrast medium exclusively (Contrast group). We evaluated differences between the two groups and performed propensity score-matched subgroup comparisons. Compared with the Contrast group, the LMWD group had worse baseline renal function, higher prevalence of diabetes mellitus and percutaneous coronary intervention history, higher C-reactive protein and N-terminal pro B-type natriuretic peptide levels, lower hemoglobin levels, and lower left ventricular ejection fraction. The median total volume of contrast medium in the Contrast group was 230.0 ml vs. 61.8 ml of LMWD in addition to 164.0 ml of contrast medium in the LMWD group. Renal function was consistently impaired in the LMWD group within 5 days, at 1-month, and 1-year follow-up (P < 0.001). Two propensity score-matched analyses adjusted for either total volume used or contrast media volume consistently indicated a trend toward worsening renal function in the LMWD group at the 1-year follow-up. No protective benefit for renal function from using LMWD instead of contrast media for OCT was observed in patients with renal insufficiency.