Practical utilization of cardiac computed tomography for the success in complex coronary intervention.

Percutaneous coronary intervention (PCI) for complex lesions is still technically demanding and is associated with less favorable procedural parameters such as lower success rate, longer procedural time, higher contrast volume and unexpected complications. Because the conventional angiographic analysis is limited by the inability to visualize the plaque information and the occluded segment, cardiac computed tomography has evolved as an adjunct to invasive angiography to better characterize coronary lesions to improve success rates of PCI. Adding to routine image reconstructions by coronary computed tomography angiography, the thin-slab maximum intensity projection method, which is a handy reconstruction technique on an ordinary workstation, could provide easy-to-understand images to reveal the anatomical characteristics and the lumen and plaque information simultaneously, and then assist to build an in-depth strategy for PCI. Especially in the treatment of chronic total occlusion lesion, these informations have big advantages in the visualization of the morphologies of entry and exit, the occluded segment and the distribution of calcium compared to invasive coronary angiography. Despite of the additional radiation exposure, contrast use and cost for cardiac computed tomography, the precise analysis of lesion characteristics would consequently improve the procedural success and prevent the complication in complex PCI.

Initial medical management in acute type A aortic dissection patients with a thrombosed false lumen in the ascending aorta combining intramural hematoma and retrograde dissection from the descending to the ascending aorta.

BACKGROUND: The feasibility of medical management for select patients with acute type A aortic dissection has been reported from a few institutions. In this study, we retrospectively investigated the safety and feasibility of our conservative approach for patients with type A aortic dissection in daily practice. METHODS: From January 2013 to December 2017, 131 consecutive patients were admitted to our institution for acute aortic dissection, including 58 patients of type A. Initial medical management was attempted in select patients who were clinically stable and had a thrombosed false lumen of the ascending aorta without ulcer-like projections in the ascending aorta. RESULTS: Except for nine patients contraindicated for surgery, urgent surgery was performed in 26 patients (SRG group), while 23 patients (MED group) were treated with the initial medical management. The maximum diameter of the ascending aorta was significantly larger in the SRG group than in the MED group. In the MED group, the heart rate and blood pressures were well-controlled at admission to the intensive-care unit, and the systolic blood pressure was further reduced at 24 h after. The in-hospital mortality rates of the MED and SRG groups were 0% and 15%, respectively. During the follow-up period, the survival rate was significantly higher in the MED group than in the SRG group, and the aortic event-free survival at one year was 80%. CONCLUSIONS: The initial medical management for select patients with a thrombosed false lumen in the ascending aorta was a safe and feasible strategy in real-world practice.

Impact of intravascular ultrasound-guided minimum-contrast coronary intervention on 1-year clinical outcomes in patients with stage 4 or 5 advanced chronic kidney disease.

This study aims to elucidate 1-year clinical outcomes using this technique for patients with stage 4 or 5 advanced chronic kidney disease (CKD). Research has proven that imaging-guided percutaneous coronary intervention (PCI) reduces contrast volume significantly; however, only short-term clinical benefits have been reported. Minimum-contrast (MINICON) studies are based on the registry design pattern to enroll PCI results in patients with advanced CKD stage 4 or 5 comorbid with coronary artery disease. We excluded cases of emergency PCI or maintenance dialysis from this study. In this study, we compared the intravascular ultrasound (IVUS)-guided MINICON PCI group (n = 98) with the angiography-guided standard PCI group (n = 86). Enrollment of the MINICON studies started in 2006. Before 2012, IVUS-guided MINICON PCI was performed only in 14% (stage 1), but it was 100% after 2012 (stage 2). The enrollment finished in 2016. The IVUS-guided MINICON PCI group exhibited a significantly reduced contrast volume (22 ± 20 vs. 130 ± 105 mL; P < 0.0001) and contrast-induced acute kidney injury (CI-AKI; 2% vs. 15%; P = 0.001). The PCI success rate was similarly high (100% vs. 99%; P = 0.35). At 1 year (follow-up rate, 100%), we observed less induction of renal replacement therapy (RRT; 2.7% vs. 13.6%; P = 0.01), but all-cause mortality or myocardial infarction was similar in both groups. The IVUS-guided MINICON PCI reduces CI-AKI significantly and induction of RRT at 1 year in patients with stage 4 or 5 advanced CKD.

The Effect of Low Frame Rate Fluoroscopy on the X-ray Dose during Coronary Intervention.

Objective The aim of this study was to investigate whether the use of low frame rate fluoroscopy at 7.5 frames per second during coronary intervention could reduce radiation exposure in Japanese patients. Methods From December 10, 2014 to March 20, 2015, 84 consecutive patients with coronary artery disease who underwent coronary intervention in our institution were retrospectively collected and then divided into two groups: the LR group (fluoroscopy at 7.5 frames per second) and the OR group (fluoroscopy at 15 frames per second), according to the frame rate of fluoroscopy that was used in their treatment. Results There were no differences in the patient backgrounds or the procedural characteristics of the two groups. Although there were no differences in the contrast volume or fluoroscopy time, the total air kerma at the interventional reference point, which is used to monitor the patient's radiation dose, was significantly lower in the LR group than in the OR group (701.4±427.9 vs. 936.8±623.9 mGy, p=0.02). Conclusion Low frame rate fluoroscopy at 7.5 frames per second is safe and feasible for use during coronary interventions and an easy and useful strategy for reducing the radiation to which patients are exposed during coronary intervention.

Resolution of a left ventricular thrombus by the thrombolytic action of dabigatran.

A 77-year-old man was referred to our cardiovascular department for detailed examination after abnormal electrocardiography findings were obtained during a preoperative cataract surgery workup. Ultrasound echocardiography (UCG) and computed tomography (CT) revealed evidence of previous myocardial infarction with anteroseptal akinesis and a left ventricular (LV) thrombus (14 × 12 mm). Dabigatran (220 mg/day) was prescribed as an outpatient treatment, and the disappearance of the LV thrombus was confirmed by UCG and CT 27 days after dabigatran initiation. No thromboembolism occurred between treatment initiation and thrombus resolution. Our results indicate that dabigatran has thrombolytic action on an acute pre-existing intracardiac thrombus.

Anatomical and electrophysiological variations of Koch's triangle and the impact on the slow pathway ablation in patients with atrioventricular nodal reentrant tachycardia: a study using 3D mapping.

OBJECTIVE: This study aimed to reveal individual variations in Koch's triangle using NavX and to evaluate the efficacy of the NavX-guided slow pathway ablation. METHODS: A regional geometry around Koch's triangle was constructed in 42 consecutive patients with atrioventricular nodal reentrant tachycardia (AVNRT), and a bipolar electrogram map was created with 72 ± 30 sampling points during sinus rhythm to identify sites with Haissaguerre's slow potentials (SPs) and His bundle electrograms (HBEs) to examine the anatomical and electrical variations. Radiofrequency ablation was performed at the most prominent SP recording site. The acute results and long-term outcome were examined in comparison to another 42 consecutive patients who underwent a conventional fluoroscopy-guided slow pathway ablation in the previous months. RESULTS: The size of Koch's triangle and the coronary sinus ostium varied over a wide range of 132 to 490 and 69 to 346 mm(2), respectively. HBEs were recorded linearly along the antero-septal right atrium (n = 29) or deviated downward toward the midseptum (n = 13, 31 %). The SPs were always distributed below the lowest HBE recording site. The NavX-guided ablation eliminated AVNRT with a median of 1 radiofrequency pulse, 9.1 ± 4.6 min of fluoroscopy, and 49 ± 14 min of procedure time, all of which were significantly smaller than those in fluoroscopy-guided ablation. No procedure-related complications or long-term recurrence was noted in either group. CONCLUSION: Koch's triangle varies in terms of the size and electrogram distribution, and the NavX-guided slow pathway ablation overcomes the diversity and seems more effective than fluoroscopy-guided ablation.

Ventricular pacing inhibition by oversensing due to diaphragmatic myopotential during deep inspiration.

An 80-year-old man, who had dilated cardiomyopathy with right ventricular (RV) dilatation, underwent implantable cardioverter defibrillator (ICD) implantation for advanced atrioventricular block and primary prevention of sudden cardiac death. Tined and screw-in leads were placed on the right atrial appendage and RV apex, respectively. Ventricular pacing inhibition was detected after surgery due to oversensing by diaphragmatic myopotential occurring only during deep inspiration. We performed re-surgery and switched the screw-in lead for a tined lead. The diaphragmatic myopotential decreased, thereby improving oversensing by diaphragmatic myopotential and ventricular pacing inhibition. It might be beneficial to use a tined lead when placing the ventricular lead at the RV apex for implantation of a pacemaker or ICD if oversensing of diaphragmatic myopotential is observed using a screw-in lead. .

Diffuse alveolar hemorrhage as a complication of dual antiplatelet therapy for acute coronary syndrome.

Diffuse alveolar hemorrhage after percutaneous coronary intervention is a rare complication that has been mostly reported in association with glycoprotein IIb/IIIa inhibitors. We herein report a case of a 64-year-old male who developed a diffuse pulmonary hemorrhage after coronary stent implantation for ST-elevation myocardial infarction. Diagnostic bronchoscopy determined the hemorrhage to be a bland pulmonary hemorrhage, and this pattern suggested that combination therapy with aspirin and ticlopidine was therefore the most likely cause. The combination of aspirin and thienopyridine agents is a routine therapeutic protocol for patients after coronary stent implantation. Therefore, physicians should be aware that this dual antiplatelet therapy might sometimes induce fatal complications.

Progressive atrial lead perforation developed 5 years after pacemaker replacement.

This report describes an asymptomatic case of atrial lead perforation which developed 5 years after pacemaker implantation. Although retrospective findings of computed tomography showed a screw-in atiral lead had already perforated 9 months after the implantation, the lead protrusion on chest X-rays and pacing failure had not been noticed until another 3 years later. At first, this complication was managed conservatively, however, a lead perforation progressively developed and, as a result, open surgery was performed to remove the lead. We therefore should be aware of the potential occurrence of a progressive protrusion of a perforated lead.

Clinical and angiographic predictors of luminal changes beyond 6 months after implantation of thicker strut coronary stents.

BACKGROUND: Late luminal changes beyond 6 months after thicker strut stent implantation have not been fully elucidated. The purpose of this study was to clarify the clinical and angiographic predictors of late changes in minimal lumen diameter (MLD) after 6-month follow-up of stenting. METHODS AND RESULTS: Fifty-one lesions from 44 patients who underwent successfully S670/660 stent (Medtronic Vascular, Santa Rosa, CA, USA) implantations without target lesion revascularization were studied at 6-month follow-up and coronary angiography was repeated after the follow-up. Late luminal loss beyond 6 months after stenting significantly correlated with late loss (r=-0.42, p=0.0025) and MLD (r=0.28, p=0.047) at 6-month follow-up. On multivariate analysis, age (p=0.005), diabetes mellitus (p=0.002), hyperlipidemia (p=0.023), smoking (p=0.015), bifurcation lesion (p=0.018), small stent diameter (p=0.001) and MLD at 6-month follow-up (p<0.001) were identified as independent predictors of late luminal loss. CONCLUSIONS: This study demonstrated that older age, diabetes mellitus, hyperlipidemia, smoking and small stent diameter (<3.0 mm) were associated with late luminal loss beyond 6 months after stenting, and that a bifurcation lesion and small lumen diameter at 6 months were associated with late luminal recovery.