Using Patient-Specific Contrast Enhancement Optimizer Simulation Software During the Transcatheter Aortic Valve Implantation-Computed Tomography Angiography in Patients With Aortic Stenosis.

OBJECTIVES: This study assessed whether patient-specific contrast enhancement optimizer simulation software (p-COP) can reduce the contrast material (CM) dose compared with the conventional body weight (BW)-tailored scan protocol during transcatheter aortic valve implantation-computed tomography angiography (TAVI-CTA) in patients with aortic stenosis. METHODS: We used the CM injection protocol selected by the p-COP in group A (n = 30). p-COP uses an algorithm that concerns data on an individual patient's cardiac output. Group B (n = 30) was assigned to the conventional BW-tailored CM injection protocol group. We compared the CM dose, CM amount, injection rate, and computed tomography (CT) values in the abdominal aorta between the 2 groups and classified them as acceptable (>280 Hounsfield units (HU)) or unacceptable (<279 HU) based on the optimal CT value and visualization scores for TAVI-CTA. We used the Mann-Whitney U test to compare patient characteristics and assess the interpatient variability of subjects in both groups. RESULTS: Group A received 56.2 mL CM and 2.6 mL/s of injection, whereas group B received 76.9 mL CM and 3.4 mL/s of injection (P < 0.01). The CT value for the abdominal aorta at the celiac level was 287.0 HU in group A and 301.7HU in group B (P = 0.46). The acceptable (>280 HU) and unacceptable (<280 HU) CT value rates were 22 and 8 patients in group A and 24 and 6 patients in group B, respectively (P = 0.76). We observed no significant differences in the visualization scores between groups A and B (visualization score = 3, P = 0.71). CONCLUSION: The utilization of p-COP may decrease the CM dosage and injection rate by approximately 30% in individuals with aortic stenosis compared with the body-weight-tailored scan protocol during TAVI-CTA.

Usefulness of the patient-specific contrast enhancement optimizer simulation software during the whole-body computed tomography angiography.

To evaluate whether the patient-specific contrast enhancement optimizer simulation software (p-COP) is useful for predicting contrast enhancement during whole-body computed tomography angiography (WBCTA). We randomly divided the patients into two groups using a random number table. We used the contrast material (CM) injection protocol selected by p-COP in group A (n = 52). The p-COP used an algorithm including data on the individual patient's cardiac output. Group B (n = 50) was assigned to the conventional CM injection protocol based on body weight. We compared the CT number in the abdominal aorta at the celiac artery level between the two groups and classified them as acceptable (> 280 HU) and unacceptable (< 279 HU) based on the optimal CT number for the WBCTA scans. To evaluate the difference in both injection protocols, we compared the visual inspection of the images of the artery of Adamkiewicz in both protocols. The CM dosage and injection rate in group A were significantly lower than those in group B (480.8 vs. 501.1 mg I/kg and 3.1 vs. 3.3 ml/s, p < 0.05). The CT number of the abdominal aorta at the celiac level was 382.4 ± 62.3 HU in group A and 363.8 ± 71.3 HU in group B (p = 0.23). CM dosage and injection rate were positively correlated to cardiac output for group A (r = 0.80, p < 0.05) and group B (r = 0.16, p < 0.05). The number of patients with an acceptable CT number was higher in group A [46/6 (86.7%)] than in group B [43/7 (71.4%)], but not significant (p = 0.71). The visualization rate for the Adamkiewicz artery was not significantly different between groups A and B (p = 0.89). The p-COP was useful for predicting contrast enhancement during WBCTA with a lower CM dosage and a lower contrast injection rate than that based on the body weight protocol. In patients with lower cardiac output a reduction in contrast injection rate and CM dosage did not lead to a reduced imaging quality, thus particularly in this group CM dosage can be reduced by p-COP.

Does the Tube Voltage Affect the Characterization of Coronary Plaques on 100- and 120-kVp Computed Tomography Scans.

OBJECTIVE: The aim of this study was to compare the diagnostic performance of 100- and 120-kVp coronary computed tomography (CT) angiography (CCTA) scans for the identification of coronary plaque components. METHODS: We included 116 patients with coronary plaques who underwent CCTA and integrated backscatter intravascular ultrasound studies. On 100-kVp scans, we observed 24 fibrous and 24 fatty/fibrofatty plaques; on 120-kVp scans, we noted 27 fibrous and 41 fatty/fibrofatty plaques. We compared the fibrous and the fatty/fibrofatty plaques, the CT number of the coronary lumen, and the radiation dose on scans obtained at 100 and 120 kVp. We also compared the area under the receiver operating characteristic (ROC) curve of the coronary plaques on 100- and 120-kVp scans with their ROC curves on integrated backscatter intravascular ultrasound images. RESULTS: The mean CT numbers of fatty and fatty/fibrofatty plaques were 5.71 ± 36.5 and 76.6 ± 33.7 Hounsfield units (HU), respectively, on 100-kVp scans; on 120-kVp scans, they were 13.9 ± 29.4 and 54.5 ± 22.3 HU, respectively. The CT number of the coronary lumen was 323.1 ± 81.2 HU, and the radiation dose was 563.7 ± 81.2 mGy-cm on 100-kVp scans; these values were 279.3 ± 61.8 HU and 819.1 ± 115.1 mGy-cm on 120-kVp scans. The results of ROC curve analysis identified 30.5 HU as the optimal diagnostic cutoff value for 100-kVp scans (area under the curve = 0.93, 95% confidence interval = 0.87-0.99, sensitivity = 95.8%, specificity = 78.9%); for 120-kVp plaque images, the optimal cutoff was 37.4 HU (area under the curve = 0.87, 95% confidence interval = 0.79-0.96, sensitivity = 82.1%, specificity = 85.7%). CONCLUSIONS: For the discrimination of coronary plaque components, the diagnostic performance of 100- and 120-kVp CCTA scans is comparable.

CT Angiography of Suspected Peripheral Artery Disease: Comparison of Contrast Enhancement in the Lower Extremities of Patients Undergoing and Those Not Undergoing Hemodialysis.

OBJECTIVE: The objective of our study was to compare contrast enhancement on CT angiography (CTA) images of the lower extremity in patients with suspected peripheral artery disease who did not undergo hemodialysis (HD) and patients who were scanned before or after HD. MATERIALS AND METHODS: We divided 287 consecutive patients who underwent CTA of the lower extremity on a 64-MDCT scanner into three groups: group 1 patients (n = 151) were not dependent on HD, group 2 patients (n = 70) were dependent on HD and underwent HD less than 24 hours after CTA, and group 3 (n = 66) were dependent on HD and underwent HD less than 24 hours before CTA. We then compared the CT number in the popliteal artery at the level of the patella on all CTA images. A cardiologist and a radiology technologist visually evaluated the depiction of the descending genicular artery (DGA) on the CTA images and assigned a visualization score. RESULTS: The median CT number was lowest in group 2 patients (373 HU vs 429 [group 1] and 418 [group 3] HU). The score for visualization of the DGA was significantly lower in group 2 than in group 1 (p = 0.02) and group 3 (p = 0.04). CONCLUSION: At CTA, arterial enhancement decreases with the passage of time after HD likely because of the increase in intravascular volume. CTA that is performed within 24 hours after HD generates higher-quality images of the lower extremities than CTA that is performed within 24 hours before HD.

Prognostic Values of Fractional Flow Reserve Based on Clinical Outcomes in Patients on Chronic Hemodialysis.

The fractional flow reserve (FFR) cut-off values of 0.75 or 0.8 have been widely used; however, whether they apply to patients on hemodialysis remains unknown. We aimed to investigate the cut-off value of FFR associated with clinical outcomes in patients on hemodialysis. Using the Japanese multicenter registry, we analyzed data of patients on hemodialysis with measured FFR between January 2010 and December 2016. Survival classification and regression tree analysis for the composite primary outcome of cardiovascular mortality, myocardial infarction, and target vessel revascularization revealed a threshold FFR of 0.83. Multivariate Cox regression analyses were performed for the clinical outcomes. Additionally, the primary outcome was analyzed using propensity score matching by dividing the patients into complete and incomplete revascularization groups according to the presence of residual lesions with an FFR of ≤0.83 after the intervention. Of the 212 included patients, 112 (52.8%) had lesions with an FFR of ≤0.83. After adjusting for confounders, an FFR of ≤0.83 was associated with a higher risk for the primary outcome (adjusted hazard ratio 2.01, 95% confidence interval 1.11 to 3.66, p = 0.021). Propensity score matching showed that complete revascularization for lesions with an FFR of ≤0.83 was associated with a reduced risk for the primary outcome compared with incomplete revascularization (hazard ratio 0.38, 95% confidence interval 0.20 to 0.71, log-rank p = 0.0016). In conclusion, an FFR of ≤0.83 was an independent predictor of clinical events in patients on hemodialysis. Furthermore, complete revascularization was associated with better clinical outcomes. Thus, this population may require a distinct FFR cut-off value.

Impact of platelet reactivity to adenosine diphosphate before implantation of drug-eluting stents on subsequent adverse cardiac events in patients with stable angina.

BACKGROUND: Diverse pharmacological effects of anti-platelet thienopyridines due to individual differences in metabolism have been reported. However, an association between on-treatment platelet reactivity and adverse ischemic events after drug-eluting stent (DES) implantation in Japanese patients has not been fully elucidated. METHODS AND RESULTS: A total of 450 consecutive patients on dual anti-platelet therapy (aspirin and ticlopidine) with stable angina who underwent DES implantation were enrolled. Adenosine diphosphate (ADP)-induced platelet aggregation was measured before DES implantation using the screen filtration pressure method. The ADP concentration necessary for 50% aggregation was designated as the platelet aggregation threshold index (PATI). A composite primary endpoint of cardiac death, myocardial infarction, target lesion revascularization (TLR), and stent thrombosis occurring within 1 year after stenting, was evaluated. A PATI value <4.8 µmol/L was defined as high on-treatment reactivity to ADP. The composite primary endpoint occurred in 55 patients (12.2%) in the 1-year-period after DES implantation, and the prevalence was 19.0% and 5.1% in groups with high and low on-treatment reactivity to ADP, respectively, showing a significantly higher prevalence in the high reactivity group (P<0.001). The main event was TLR (18.1% vs. 5.1%, P<0.001). CONCLUSIONS: These data suggested that high on-treatment platelet reactivity to ADP and subsequent occurrence of adverse ischemic events (particularly TLR) were correlated in patients with stable angina who underwent DES implantation.

Beneficial effects of valsartan on target lesion revascularization after percutaneous coronary interventions with bare-metal stents.

BACKGROUND: Angiotensin II receptor blockers (ARB) have been shown to reduce cardiovascular events in patients at risk. The effect of valsartan on outcomes after percutaneous coronary interventions (PCI) with bare-metal stents (BMS) was investigated. METHODS AND RESULTS: The prospective, randomized study included 191 patients at 5 participating institutions, who were randomly assigned to either a 40-80 mg valsartan add-on or non-ARB treatment. The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, and target lesion revascularization (TLR) at 18 months. Enrollment was stopped when the use of drug-eluting stents has been expanded in Japan. No significant differences existed between the groups in terms of primary endpoint (18.9% vs. 24.8%; hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.61-1.14; P = 0.26). In the valsartan group, as compared with the non-ARB group, the secondary endpoint of TLR was significantly reduced at a median follow-up 4.4 years; the rate of TLR was from 27.8% to 14.5% (HR, 0.69; 95%CI, 0.49-0.96; P = 0.024). CONCLUSIONS: Valsartan treatment was not superior to non-ARB treatment in reducing the primary endpoint after PCI at 18 months. The pre-specified secondary endpoint of TLR was lower in the valsartan group, but this needs to be proved statistically with an adequate study sampling.

Clinical outcomes of sirolimus-eluting stenting after rotational atherectomy.

BACKGROUND: The efficacy of drug-eluting stents after rotational atherectomy (ROTA) has not been clarified. METHODS AND RESULTS: The 704 consecutive patients who underwent percutaneous coronary intervention (PCI) with a sirolimus-eluting stent (SES) (79 with and 625 without ROTA) were enrolled. The 2-year clinical outcome of these patients was compared with that of a group of 1,123 consecutive patients treated with bare-metal stents (BMS) (144 with and 979 without ROTA). At 2 years after index PCI, the use of SES after ROTA was associated with a lower crude incidence of major adverse cardiac events (MACE) than were BMS after ROTA (30.1% vs 43.1%, P=0.024). The difference was mainly derived from the reduction in target lesion revascularization (TLR) (25.0% vs 39.1%, P=0.022). After adjusting for confounders, ROTA-SES was associated with a reduction in MACE and TLR, with a similar hazard ratio to the non-ROTA group only with SES implantation. In a subgroup of dialysis patients, the incidence of TLR after ROTA with SES and BMS was similarly high. CONCLUSIONS: The use of SES after ROTA is an appropriate method for selected hard lesions, but has a limited effect in dialysis patients, even after lesion preparation with ROTA.

Machine-learning integration of CT histogram analysis to evaluate the composition of atherosclerotic plaques: Validation with IB-IVUS.

BACKGROUND: To determine whether machine learning with histogram analysis of coronary CT angiography (CCTA) yields higher diagnostic performance for coronary plaque characterization than the conventional cut-off method using the median CT number. METHODS: We included 78 patients with 78 coronary plaques who had undergone CCTA and integrated backscatter intravascular ultrasound (IB-IVUS) studies. IB-IVUS diagnosed 32 as fibrous- and 46 as fatty or fibro-fatty plaques. We recorded the coronary CT number and 7 histogram parameters (minimum and mean value, standard deviation (SD), maximum value, skewness, kurtosis, and entropy) of the plaque CT number. We also evaluated the importance of each feature using the Gini index which rates the importance of individual features. For calculations we used XGBoost. Using 5-fold cross validation of the plaque CT number, the area under the receiver operating characteristic curve of the machine learning- (extreme gradient boosting) and the conventional cut-off method was compared. RESULTS: The median CT number was 56.38 Hounsfield units (HU, 8.00-95.90) for fibrous- and 1.15 HU (-35.8-113.30) for fatty- or fibro-fatty plaques. The calculated optimal threshold for the plaque CT number was 36.1 ±â€¯2.8 HU. The highest Gini index was the coronary CT number (0.19) followed by the minimum value (0.17), kurtosis (0.17), entropy (0.14), skewness (0.11), the mean value (0.11), the standard deviation (0.06), and the maximum value (0.05), and energy (0.00). By validation analysis, the machine learning-yielded a significantly higher area under the curve than the conventional method (area under the curve 0.92 and 95%, confidence interval 0.86-0.92 vs 0.83 and 0.75-0.92, p = 0.001). CONCLUSION: The machine learning-was superior the conventional cut-off method for coronary plaque characterization using the plaque CT number on CCTA images.

Transcatheter aortic valve implantation for severe aortic stenosis in dextrocardia with situs inversus using a self-expanding aortic valve.

Transcatheter aortic valve implantation (TAVI) has evolved into a standard therapy for aged patients with severe aortic valve stenosis who are not candidates for surgery. However, the reports about the safety of TAVI for patients with dextrocardia situs inversus are few. An 84-year-old man with dextrocardia situs inversus underwent a TAVI for severe aortic stenosis (AS) with an aortic valve area of 0.5 cm2, and a mean pressure gradient of 46 mmHg. Preoperative computed tomography (CT) revealed an inverted (rightward) orientation of the ventricle apex as well as the great vessels. The TAVI was performed through a transfemoral approach under general anesthesia. A left and right reversed fluoroscopic image was used for the TAVI. Finally, a 26-mm CoreValve Evolut R (Medtronic, Minneapolis, MN, USA) was successfully deployed at the aortic annulus under angiographic guidance. Post-procedural transthoracic echocardiography demonstrated a well-functioning CoreValve Evolut R with a mean pressure gradient of 8 mmHg. No complications occurred during the procedure or peri-procedural period. The patient's symptoms subsequently improved from New York Heart Association class III to class I. In conclusion, a TAVI procedure was safely performed in a patient with dextrocardia situs inversus through a transfemoral approach by evaluating the anatomical details with preoperative CT. .

Radiation Dose Reduction at Low Tube Voltage CCTA Based on the CNR Index.

RATIONALE AND OBJECTIVES: We compared the radiation dose and diagnostic accuracy on 120- and 100-kVp coronary computed tomography angiography (CCTA) scans whose contrast-to-noise ratio (CNR) was the same. MATERIALS AND METHODS: We studied 1311 coronary artery segments from 100 patients. For 120-kVp scans, the targeted image level was set at 25 Hounsfield units (HU). For 100-kVp scans, the targeted noise level was set at 30 HU to obtain the same CNR as at 120 kVp. We compared the CNR and the radiation dose on scans acquired at 120 and 100 kVp. Invasive coronary angiography (ICA) images were evaluated by an interventional coronary angiography specialist, and CCTA images were evaluated by a radiologist. Coronary artery disease was defined as a luminal narrowing ≧50% for ICA and CCTA. With ICA considered the gold standard, the diagnostic accuracy (sensitivity, specificity, positive predictive value, and negative predictive value) was analyzed on both 120- and 100-kVp CCTA images. We also compared the diagnostic accuracy for area under the receiver operating characteristic curve of the ICA and CCTA performed at 120 and 100 kVp. Two blinded observers visually evaluated the septal branch. RESULTS: The mean dose-length product was 48% lower at 100 kVp than at 120 kVp (P < .01). Under the 120-kVp CCTA protocol, the area under the curve, 95% confidence interval, sensitivity, specificity, positive predictive value, and negative predictive value were 0.94%, 0.91%-0.96%, 94.0%, 93.0%, 82.3%, and 98.1%, respectively; at 100 kVp these values were 0.94%, 0.92%-0.97%, 96.1%, 92.0%, 85.2%, and 98.0%, respectively. Area under the receiver operating characteristic curve analysis revealed no significant difference in diagnostic accuracy between the two protocols (P = .87). CONCLUSIONS: At the same CNR, the 100-kVp CCTA protocol may help to reduce the radiation dose by approximately 50% compared to the 120-kVp protocol without degradation of diagnostic accuracy.

Coronary plaque characteristics in computed tomography and 2-year outcomes: The PREDICT study.

BACKGROUND: Coronary computed tomography angiography (CCTA) not only provides information regarding luminal stenoses but also allows for visualization of mural atheromatous changes (coronary plaques). OBJECTIVE: We sought to elucidate whether plaques seen on CCTA enable prediction of 2-year outcomes in patients with suspected and known coronary artery disease (CAD). METHODS: Of 3015 patients who underwent CCTA, the images and 2-year clinical courses of 2802 patients were independently analyzed. The primary endpoint was the composite of all-cause death and acute coronary syndrome. RESULTS: During the 2-year observation period, 49 (1.7%) patients developed the primary outcome. The 2-year rates of the primary outcome in the normal (n = 515, no mural lesions), calcium (n = 654, calcified lesion alone), and plaque groups (n = 1633, presence of noncalcified or partially calcified plaques) were 0.2%, 2.0%, and 2.1%, respectively (P = 0.0028). Adverse plaque features such as low attenuation, positive remodeling, spotty calcification, and the napkin-ring sign (low-attenuation core with a higher-attenuation rim) were assessed by an independent core laboratory. Stepwise multivariate Cox proportional hazard analysis showed that a plaque with two or more characteristics (adjusted hazard ratio, 1.98; 95% confidence interval, 1.09-3.60; P = 0.0254), age of ≥67 years (mean), statin treatment after CCTA, and obstructive stenosis remained independent predictors of the primary outcome. CONCLUSIONS: Plaque imaging in CCTA has predictive value for the 2-year outcome and is a useful identifier for high-risk patients among those with known and suspected CAD.

Comprehensive evaluation of noncalcified coronary plaque characteristics detected using 64-slice computed tomography in patients with proven or suspected coronary artery disease.

BACKGROUND: Multislice computed tomography has recently been shown to have the potential to characterize noncalcified coronary atherosclerotic lesions (NCALs). We evaluated the relationship among computed tomography (CT) density, arterial remodeling, and the adherent calcium morphology of NCALs detected using 64-slice CT. METHODS: We studied 138 patients with proven or suspected coronary artery disease who underwent contrast-enhanced 64-slice CT examination. For each NCAL detected within the vessel wall, we determined the minimum CT density, remodeling index (RI = lesion/reference vessel area), and the presence or absence of coronary calcium in or adjacent to each NCAL and its morphology. Intravascular ultrasound (IVUS) was additionally performed in a subset of 21 patients. RESULTS: A total of 202 NCALs were detected in 97 patients. The mean CT density of 98 lesions with positive remodeling (PR) (RI >1.05) was significantly lower than that of 104 lesions without PR (25 +/- 23 vs 56 +/- 28 Hounsfield units, P < .001); and spotty calcium was more frequently observed with the PR lesions than non-PR lesions (59% vs 22%, P < .001). The mean CT density of the PR lesions with spotty calcium (n = 58) was substantially lower than that of the non-PR lesions without adherent calcium (n = 45) (20 +/- 20 vs 67 +/- 24 Hounsfield units, P < .001). Evaluation of the components, RI, and adherent calcium morphology of 38 NCALs by 64-slice CT was in close agreement with the IVUS findings. CONCLUSIONS: Lower CT density, PR, and adherent spotty calcium, which may indicate plaque vulnerability, are intimately co-related in NCALs detected using 64-slice CT; these findings are consistent with those of IVUS.

A case of subacute stent thrombosis after drug-coated balloon coronary angioplasty for in-stent restenosis under single anti-platelet therapy.

This report describes a case of subacute stent thrombosis (SAT) after drug-coated balloon (DCB). A 79-year-old male was investigated for stable angina. An in-stent restenosis (ISR) lesion was detected by coronary angiography. A skin reaction related to the anti-platelet agent thienopyridine was also observed at this time. Therefore, DCB was used to treat the ISR lesion under single anti-platelet therapy (aspirin). However, 3 days after percutaneous coronary intervention, SAT occurred. OCT did not reveal the underlying cause of SAT. Further data are needed to clarify the optimal duration of dual anti-platelet therapy after DCB.

Contrast-induced Hyperemia as an Alternative to Drug-induced Hyperemia in the Evaluation of the Fractional Flow Reserve in Coronary Lesions.

Objective Measuring the fractional flow reserve (FFR) requires the induction of coronary hyperemia, usually with adenosine, adenosine triphosphate (ATP), or papaverine. However, adenosine can induce rhythmic complications, and intracoronary boluses of papaverine that prolong the QT interval can cause ventricular tachycardia. Injection of contrast media, which is routinely performed to validate the FFR guidewire placement, also induces hyperemia and may be an alternative method of measuring the FFR. We evaluated the diagnostic accuracy of the FFR after contrast hyperemia (FFRcont) compared to FFR evaluated after intracoronary papaverine (FFRpp). Methods This study included 109 lesions in 93 patients (mean age 70.4±8.7 years) with stable coronary disease. The FFR was measured as follows: 1) baseline pressure value; 2) FFRcont after intracoronary contrast injection (iopamidol, 8 mL for left coronary artery [LCA] or 6 mL for right coronary artery [RCA]); 3) FFRpp after intracoronary injection of papaverine (12 mg for LCA or 8 mg for RCA). Results FFRcont values were strongly correlated with FFRpp (R=0.940, p<0.0001; FFRpp = FFRcont ×1.007-0.032). The best cut-off point in the receiver operator curve analysis for predicting a FFRpp <0.80 was 0.82 (area under the curve =0.980; sensitivity 95.1%, specificity 91.2%, positive predictive value 86.7%, negative predictive value 96.9%). Conclusion FFRcont is highly accurate for predicting FFRpp. An FFRcont threshold value of 0.82 provides excellent sensitivity and a negative predictive value. FFRcont is an alternative method of inducing hyperemia.

Partial left superior pulmonary vein potential elimination by an inferior ganglionated plexus ablation.

Ganglionated plexus (GP) plays an important role in the initiation and maintenance of atrial fibrillation (AF). The GP ablation has been found to be effective for AF treatment. In this case, we reported an AF case in which the pulmonary vein (PV) potentials of the anterior region of the left superior PV were eliminated by an inferior right GP ablation.

Atrial electrical abnormality in patients with Brugada syndrome assessed by signal-averaged electrocardiography.

BACKGROUND: Ventricular fibrillation and atrial fibrillation are well-known arrhythmias in patients with Brugada syndrome. This study evaluated the characteristics of the atrial arrhythmogenic substrate using the signal-averaged electrogram (SAECG) in patients with Brugada syndrome. METHODS: SAECGs were performed during normal sinus rhythm in 23 normal volunteers (control group), 21 patients with paroxysmal atrial fibrillation (PAF; PAF group), and 21 with Brugada syndrome (Brugada group). RESULTS: The filtered P wave duration (fPd) in the control, Brugada, and PAF groups was 113.9±12.9ms, 125.3±15.0ms, and 137.1±16.3ms, respectively. The fPd in the PAF group was significantly longer compared to that in the control and Brugada groups (p<0.05). The fPd in the Brugada group was significantly longer than that in the control group (p<0.05) and significantly shorter than that in the PAF group (p<0.05). CONCLUSION: Patients with Brugada syndrome had abnormal P waves on the SAECG. The abnormal P waves on the SAECG in Brugada syndrome patients may have intermediate characteristics between control and PAF patients.

A Comparison between the Instantaneous Wave-free Ratio and Resting Distal Coronary Artery Pressure/Aortic Pressure and the Fractional Flow Reserve: The Diagnostic Accuracy Can Be Improved by the Use of both Indices.

Objectives The fractional flow reserve (FFR) is an index of the severity of coronary stenosis that has been clinically validated in several studies. The instantaneous wave-free ratio (iFR) and the resting distal coronary artery pressure/aortic pressure (Pd/Pa) are nonhyperemic pressure-derived indices of the severity of stenosis. This study sought to examine the diagnostic accuracy of the iFR and resting Pd/Pa with respect to hyperemic FFR. Methods Following an intracoronary injection of papaverine, the iFR, resting Pd/Pa, and FFR were continuously measured in 123 lesions in 103 patients with stable coronary disease. Results The iFR and resting Pd/Pa values were strongly correlated with the FFR (R=0.794, p<0.001, R=0.832, p<0.0001, respectively). A receiver operator curve (ROC) analysis revealed that the optimal iFR cut-off value for predicting an FFR of <0.80 was 0.89 (AUC 0.901, sensitivity 84.1%, specificity 80.0%, positive predictive value 69.8%, negative predictive value 90.0%, diagnostic accuracy 81.3%), while the optimal resting Pd/Pa cut-off value was 0.92 (AUC 0.925, sensitivity 90.9%, specificity 78.5%, positive predictive value 70.2%, negative predictive value 93.9%, diagnostic accuracy 82.9%). The lesions with an iFR value of ≤0.89 and a Pd/Pa value of ≤0.92 were defined as double-positive lesions, while the lesions with an iFR value of >0.89 and a Pd/Pa value of >0.92 were defined as double-negative lesions. In these 109 lesions, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 92.3%, 82.9%, 75.0%, 95.1%, and 86.2%, respectively. Conclusion This analysis demonstrated that the iFR and resting Pd/Pa were strongly correlated with the FFR and that the diagnostic accuracy of the iFR was similar to that of the resting Pd/Pa. The diagnostic accuracy can be improved with the use of both the iFR and the resting Pd/Pa.

The Difference between the optical coherence tomography (OCT) findings of newly progressed coronary lesions in symptomatic and asymptomatic patients.

BACKGROUND: Generally, newly progressed coronary lesions (NPCLs) are considered to be composed of lipid-rich plaques. In case of vulnerable plaque rupture, they may quickly become culprit lesions responsible for acute coronary syndromes. METHODS: Between September 2011 and September 2015, 2034 patients underwent scheduled follow-up coronary angiography (CAG) after percutaneous coronary intervention (PCI) in Tsuchiya General Hospital. Patients with NPCLs found by CAG during the follow-up period were evaluated by optical coherence tomography (OCT). NPCLs were defined as the lesions with less than 50% diameter stenosis, which progressed to more than 75% diameter stenosis within 3years after the previous CAG. Patients with restenosis after PCI were excluded. We compared OCT findings of NPCLs between symptomatic and asymptomatic patients. RESULTS: The follow-up CAG showed NPCLs in 64 patients (3.2%). OCT revealed fibrous plaque in 42 patients (65.6%) and thin-cap fibroatheroma in one patient. Thirteen patients had chest symptoms for one month before CAG and the remaining 51 patients were asymptomatic. The prevalence of fibrous plaque and intimal disruption or plaque rupture were not significantly different between symptomatic and asymptomatic patients (61.5% vs. 66.7%, p=0.752 and 30.8% vs. 11.8%, p=0.213, respectively). However, thrombi were more frequently observed in symptomatic patients (61.5% vs. 13.7%, p<0.001). CONCLUSIONS: The majority of NPCLs found in asymptomatic patients at follow-up CAG were not vulnerable; however, those found in symptomatic patients might be vulnerable. In clinical practice, NPCLs found in asymptomatic patients should be evaluated for functional severity of stenosis in order to determine the need for coronary revascularization.