Correction to: Switching from Warfarin to rivaroxaban induces sufficiency of vitamin K and reduction of arterial stiffness in patients with atrial fibrillation.

In the original publication of the article,one of the author's name was published incorrectly as "Takamoto Furuki".

Switching from Warfarin to rivaroxaban induces sufficiency of vitamin K and reduction of arterial stiffness in patients with atrial fibrillation.

Use of chronic vitamin K antagonist (VKA) induces a long-term deficiency of vitamin K, which may cause arterial stiffness and bone-related disease. Switching from VKA to rivaroxaban could induce rapid sufficiency of vitamin K and improvement of arterial stiffness. The K2 SUMMIT-3 study is a multicenter, open-label, prospective, and randomized design. Patients with atrial fibrillation who have been taking VKA for more than 6 months but less than 10 years were randomly assigned to two groups; those switching from VKA to rivaroxaban and those continuing with VKA medication. The primary endpoint was the percentage difference of brachial-ankle pulse wave velocity (baPWV) in 3 months. A total of 77 patients were randomly assigned to receive rivaroxaban (n = 38) or VKA (n = 39). The average age was 74 ± 9 years. The duration for which VKA was prescribed prior to randomization was 90 ± 87 months.Abnormally high levels of Des-gamma carboxyprothrombin (PIVKA-II) or uncarboxylated osteocalcin (ucOC) indicating vitamin K insufficiency were observed in 100% or 82% of the patients at baseline but it reduced to 2% (p < 0.0001) or 55% (p = 0.01) at 3 months in the rivaroxaban group. To the contrary, theses data had no changes in the VKA group. The percentage difference in baPWV was - 1.4 ± 10.0% vs. 3.5 ± 14.7% in the rivaroxaban and the VKA groups, respectively. (p = 0.02). Switching from VKA to rivaroxaban resulted in rapid sufficiency of vitamin K and reduction of arterial stiffness in 3 months.

Zero Contrast Coronary Intervention Using Intravascular Ultrasound Guidance in a Patient with Allergy to Contrast Medium.

The occurrence of allergy to iodinated contrast in certain patients may prevent the use of percutaneous coronary intervention (PCI) in such cases. We present a 53-year-old male with a history of allergic reaction to iodinated contrast who successfully underwent intravascular ultrasound (IVUS) guided PCI. Stent size was determined based on IVUS. After PCI, stent expansion and a lack of edge dissection or incomplete apposition were confirmed by IVUS. Thus, PCI without contrast injection under IVUS may be feasible in selected patients with allergy to iodinated contrast.

Acute compartment syndrome occurring in forearm with relatively small amount of hematoma following transradial coronary intervention.

A 59-year-old female with angina pectoris successfully underwent percutaneous coronary intervention via the right radial artery. She complained of right forearm pain and numbness 4.5 h after the procedure. Though the swelling in her right arm seemed relatively mild, pressure measurement showed significant increase of internal forearm pressure. She developed acute compartment syndrome in the right forearm, and fasciotomy was performed immediately. The weight of subcutaneous hematoma in her right arm was approximately 100 g. Symptoms of paralysis and the impairment of perception remained for some time, but had completely recovered 4 months post-surgery.

A case of percutaneous coronary intervention procedure successfully bailed out from multiple complications in hemodialysis patient.

A 73 year-old male who underwent coronary artery bypass surgery (CABG) 8 years ago had PCI performed on him for a diffuse calcified stenotic lesion in the right coronary artery (RCA). Following 2.5 mm non-compliant balloon dilatation supported with a child catheter (Dio from Goodman), we implanted a stent to the distal RCA through this catheter. However, because the tip of Dio was trapped by the implanted stent, it was stretched and almost ruptured by pulling it. Next, we tried to implant a stent for mid RCA with buddy wire technique, but we could not deploy it because of calcification. When we tried to withdraw this stent system, the stent was accidentally dislodged from the balloon. We could withdraw the stent with twisting two wires. However, because one of these wires had crossed a small artery in the distal RCA at twisting, a tip of this wire was fractured when the stent was removed. We could remove this wire with gooseneck snare. Finally, we successfully implanted stents in the mid RCA with balloon anchor technique and to the proximal RCA.

Impact of chronic kidney disease on clinical and angiographic results following implantation of sirolimus-eluting coronary stents.

Although sirolimus-eluting stent (SES) is effective to reduce restenosis, the effect of SES for patients with chronic kidney disease (CKD) has been ambiguous. SES were exclusively implanted into 304 lesions in 195 patients. Forty-seven percent of the patients had diabetes. Patients were divided into three groups by estimated glomerular filtration rate, CKD stage 0-2: 156 patients, 239 lesions; CKD stage 3-4: 21 patients, 37 lesions; and CKD stage 5: 18 patients, 28 lesions. Clinical follow-up data were available in 97% at 616 ± 192 days. There was a statistically significant association between the stage of CKD and target lesion revascularization (TLR) (CKD 0-2: 2.7%, CKD 3-4: 5.3%, and CKD 5: 11.9%; P = 0.011), and late lumen loss at 8 months (CKD 0-2: 0.13 ± 0.25 mm, CKD 3-4: 0.27 ± 0.47 mm, and CKD 5: 0.37 ± 0.61 mm; P = 0.0032). The frequency of clinical adverse events was also higher according to stages of CKD. In conclusion, stages of CKD proportionally correlated with TLR, late lumen loss and major adverse cardiac events following SES implantation.

Intravascular ultrasound criteria for determination of optimal longitudinal positioning of sirolimus-eluting stents.

BACKGROUND: Several studies have indicated that the clinical outcomes of sirolimus-eluting stents (SES) are significantly associated with longitudinal positioning of the stent relative to the underlying plaque distribution. METHODS AND RESULTS: Optimal SES landing was determined using unique stepwise intravascular ultrasound (IVUS) criteria, mainly targeting the sites with plaque burden <50% (plaque area/external elastic membrane area x100). To verify the criteria, (1) achievability and (2) actual impact on clinical and angiographic outcomes were assessed. A total of 162 consecutive patients with 180 lesions were enrolled and treated according to the IVUS criteria. Plaque burden at the proximal and distal margins was 41.4+/-13.6% (n=144) and 34.9+/-15.6% (n=170), respectively (within 3 mm of stent ends). The target was achieved in 72.3% of the proximal and 84.1% of the distal margin for the criteria. A strikingly low angiographic margin re-stenosis rate (2.7% of proximal and 1.4% of distal margin) and low target lesion revascularization rate (2.2%) were achieved. Receiver operator characteristic curve indicated that plaque burden was the strongest predictor of margin re-stenosis and its threshold (51.6%) was almost identical to that of the criteria. CONCLUSIONS: The proposed stepwise IVUS criteria mainly targeting plaque burden <50% are feasible and useful in the real-world practice of SES implantation.

Magnetic resonance imaging is accurate to detect bleeding in the seminal vesicles in patients with hemospermia.

OBJECTIVE: To confirm the presence of hemorrhage in the seminal vesicles by aspiration in patients with findings suspicious for hemorrhage on magnetic resonance imaging (MRI); and to investigate the relationship between findings on MRI and the freshness of hemorrhage. METHODS: Twenty-six patients with hemospermia who showed high-intensity signals on T1-weighted images with or without low-intensity signals on T2-weighted images, suggesting seminal vesicle hemorrhage, were analyzed. Of the 26, 15 underwent transperineal aspiration of the seminal vesicles under transrectal ultrasound guidance to confirm the bleeding. RESULTS: Bloody fluid was aspirated from all seminal vesicles showing a pattern suggestive of bleeding on MRI. The morphologic analysis of red blood cells in the fluid indicated relatively fresh hemorrhage in the seminal vesicles showing high-intensity signals on T1-weighted images and low-intensity signals on T2-weighted images (group A), but old hemorrhage in those showing high-intensity signal on T1-weighted images as well as T2-weighted images (group B). In 3 patients of group A who did not receive aspiration, repeated MRI during the follow-up showed that the signal intensity changed from low to high on T2-weighted images. On the other hand, in 2 patients of group B who received aspiration, repeated MRI performed 12 and 7 days after aspiration showed low signal intensity on T2-weighted images. CONCLUSIONS: Hemorrhage is really present in the seminal vesicles if high signal intensity is observed on T1-weighted images. The patterns showing low and high signal intensities on T2-weighted images suggest relatively fresh and old bleeding, respectively.

Functional formula to determine adequate balloon diameter of simultaneous kissing balloon technique for treatment of bifurcated coronary lesions: clinical validation by volumetric intravascular ultrasound analysis.

BACKGROUND: Final kissing balloon technique (KBT) is known to alter long-term clinical outcomes for treatment of bifurcated coronary lesions. However, determination of adequate diameters of the 2 balloons remains difficult because of lack of a working index. METHODS AND RESULTS: Twenty-one cases of left main (LM)-related bifurcated lesions, treated with Cypher(TM) stents (single/crush stenting) and final KBT, were enrolled. The formula "R(2) = D(1)(2) + D(2)(2)" was used, adjusting balloon diameter (D(1), D(2)) to the downstream branches, to predict the theoretical mean hugging balloon diameter (R) within the main portion. The degree and pattern of stent expansion in the LM and main branch (MB) segments was compared by volumetric intravascular ultrasound assessment. Stents in the LM segments expanded to a greater extent and more asymmetrically than in MB segments (average stent area: 13.2+/-3.1 mm(2) vs 7.6+/-2.1 mm(2), p<0.0001, stent symmetry index: 0.77+/-0.08 vs 0.88+/-0.03, p<0.0001). The actual mean stent diameter significantly correlated with R (p=0.0003, r=0.76). The ratio of actual to theoretical stent expansion was highly consistent between the LM and MB (93.1% vs 93.4%, p=NS). CONCLUSION: The proposed formula may be useful for predicting resultant stent expansion following KBT, despite a more elliptical dilation.

[Frequency and characteristics of incomplete stent apposition during and after sirolimus-eluting stent implantation].

OBJECTIVES: Incomplete stent apposition (ISA) is frequently observed after sirolimus-eluting stent (SES) implantation. This study investigated the incidence, morphological features, and possible mechanisms of this phenomenon. METHODS: Fifty-two lesions in 47 eligible patients were treated with SES and serial intravascular ultrasound (IVUS) assessment at the time of post-intervention and 8-month follow-up. ISA was carefully identified from the IVUS images of these lesions. Specifically, quantitative two dimensional IVUS analysis was performed if the lesions demonstrated ISA, including routine IVUS parameters as well as other measurements related to ISA. RESULTS: Overall, ISA was observed in 13 lesions (25.0%) at follow-up. Persistent ISA (n = 6, 11.5%), defined as ISA consistently observed both at post-intervention and follow-up, and late-acquired ISA (n = 7, 13.5%)were systematically compared. Eighty-three percent of cases of persistent ISA were located around the stent edges, whereas all cases of late-acquired ISA were in the stent body. In the persistent ISA group, no serial changes were observed in the lumen area or external elastic membrane area (EEMA) from post-intervention to follow-up. However, in the late-acquired ISA group, EEMA and lumen area significantly increased from post-intervention to follow-up (EEMA: 13.4 +/- 3.2 vs 17.6 +/- 3.3 mm2, respectively, p < 0.0001 ; lumen area: 6.7 +/- 1.4 vs 9.2 +/- 1.8 mm2, respectively, p = 0.004). No adverse clinical events were observed in either group. CONCLUSIONS: ISA was frequently observed during and after SES implantation in clinical practice. No clinical disadvantages were observed during 16 month clinical follow-up periods. Positive remodeling may potentially cause late-acquired ISA.

The physics of guiding catheters for the left coronary artery in transfemoral and transradial interventions.

BACKGROUND: The backup force of a guiding catheter is important for successful percutaneous coronary intervention (PCI), however, no theory has been proposed thus far regarding the factors involved in its generation. METHODS AND RESULTS: The backup force of guiding catheters was measured in an arterial tree model. In vitro modeling showed that larger-sized guiding catheters had greater backup force (8 Fr > 7 Fr > 6 Fr). Comparing the backup force between transfemoral (TFI) and transradial interventions (TRI), it was found to be 60% greater in TFI with a Judkins L (JL) catheter, and 8% greater in TFI with a backup (EBU/XB) type catheter. However, the Ikari L (IL) catheter generated a similar backup force between TRI and TFI. In TRI, the Ikari guiding catheter showed the greatest backup force, especially in the power position (power position of IL4 > IL4 > backup type 3.5 > deep engagement of JL4 > JL3.5 > JL4). These findings were associated with the angle of the catheter on the reverse side of the aorta. We then constructed several catheters with varying contact lengths. In vitro modeling showed that a longer contact area increased the backup force. CONCLUSIONS: The present model showed that three factors were associated with backup force: (1) catheter size; (2) angle on the reverse side of the aorta; and (3) contact area. The Ikari guiding catheter comprises all of the preferable factors in TRI.