Borg's exertion scale did not coincide with ventilatory anaerobic threshold in atrial fibrillation patients with restored sinus rhythm after ablation

The determination of precise exercise intensity is essential for effective exercise rehabilitation. The Borg rating of perceived exertion category ratio (CR) scale is utilized to prescribe an appropriate level of exertion intensity. A Borg CR of approximately 13 coincides with the ventilatory aerobic threshold (VAT). Patients with atrial fibrillation (AF) exhibit various symptoms. We hypothesized that the workload at Borg CR13 (Borg CR13-Watt) differs from the workload at the VAT level (VAT-Watt) in AF patients with restored sinus rhythm (SR) following ablation. Accordingly, the relationship between Borg CR13-Watt and VAT-Watt was studied in patients with restored SR. Cardiopulmonary exercise testing (CPET) was performed at 101±88 days after ablation in 150 patients using a bicycle ergometer. No adverse events were observed during CPET. Borg CR13-Watt was significantly higher than VAT-Watt (67.2±27.8 Watt vs. 54.7±17.6 Watt, P<0.0001). Borg CR13-Watt showed significant linear regression with VAT-Watt (regression coefficient, 0.49, P<0.01; correlation coefficient, 0.80, P<0.01). Higher Borg CR13-Watt was associated with greater differences between Borg CR13-Watt and VAT-Watt (ΔWatt). The Bland-Altman plot showed nonconcordance between the two. Male sex, use of antiarrhythmic drugs, and smoking had contributed to the increased ΔWatt. Duration from ablation to time of CPET did not correlate with ΔWatt. Therefore, Borg CR13-Watt did not coincide with VAT-Watt in patients with restored SR. Higher Borg CR13-Watt was associated with greater ΔWatt. Prescribing exertion intensity as determined solely by perceived exertion is inadequate. CPET is required to determine the precise exercise intensity in AF patients with restored SR after ablation.

Incidence of nausea/vomiting following propofol sedation with adaptive servo-ventilation for atrial fibrillation ablation

Background

Postoperative nausea and vomiting (PONV) following atrial fibrillation (AF) ablation can cause considerable distress.

Aim

Continuous intravenous propofol sedation with adaptive servo-ventilation (ASV) with or without an analgesic, pentazocine, during AF ablation was studied in 272 consecutive patients with paroxysmal, persistent, and long-standing persistent AF. The study objectives were to determine the incidence of PONV after AF ablation and to assess the predictive value of factors for PONV using the area under the receiver operating characteristic curve (AUC).

Results

The present sedation maneuver was successfully accomplished with a low incidence of hypotension and without discontinuation of ablation or switching to general anesthesia, while maintaining an acceptable procedural time (102 ± 32 min). The incidence of PONV was 5.5% (15/272). Nausea occurred in nine patients after an average of 4.6 ± 3.5 h (range: 2-12 h) postablation, and vomiting with nausea occurred in six patients after an average of 4.5 ± 3.1 h (range: 1-9 h) postablation. The postablation interval did not differ significantly between the occurrence of nausea and nausea accompanied by vomiting. AUCs based on various factors, including the Apfel score, ranged from 0.55 to 0.67, indicating low accuracy in predicting PONV occurrence.

Conclusions

The incidence of PONV after propofol sedation with ASV was the lowest (5.5%) reported to date. Scoring systems, which included the Apfel score, were ineffective in predicting PONV. The low PONV incidence in addition to the efficacy of propofol sedation with ASV revealed the adequacy of this regimen for AF ablation.

Usefulness of three-dimensional pulmonary vein-left atrium image reconstructed from non-enhanced computed tomography for atrial fibrillation ablation

Enhanced computed tomography (CT) is unsuitable for patients with reduced renal function and/or allergy for contrast medium (CM). CT image registration into an electroanatomic system (EAMS) is essential to perform pulmonary vein isolation (PVI) safely and smoothly in patients with atrial fibrillation (AF). To create three-dimensional pulmonary vein-left atrium (3D PV-LA) images from non-enhanced CT images to register them into EAMS for AF ablation. Using a non-enhanced ECG-gated image, 3D PV-LA images were generated by our developed techniques with an EnSite image analyzing tool for patients unfit for CM use (n = 100). Segmentation between tissues was performed as follows: tissues distal from or close to PV-LA were segmented in transverse slices to clearly show the whole LA. Tissues bordering PV-LA, including the pulmonary artery, left ventricle, and right atrium, were segmented manually with great care. Practical ablation parameters were compared with those obtained from enhanced CT (n = 100). 3D PV-LA image reconstruction from non-enhanced CT imaging required a longer time than that from enhanced CT (42 ± 6 vs 14 ± 3 min). All 100 PV-LA non-enhanced CT images were successfully reconstructed and registered into the EAM system without the need for re-segmentation. Practical ablation parameters, including procedural time and AF recurrence rate, did not differ between imaging methods. This study provides clinically useful information on a detailed methodology for 3D PV-LA image reconstruction using non-enhanced CT. Non-enhanced CT 3D PV-LA images were successfully registered into the EAM system and useful for patients unsuitable for CM use.

Reproducibility of cardiopulmonary exercise testing between one after and 1-3 weeks after elective percutaneous coronary intervention

Prompt prescription and early initiation of exercise training are essential for patients undergoing elective percutaneous coronary intervention (PCI). We hypothesized that cardiopulmonary exercise testing (CPET) parameters determined the day after elective PCI during hospitalization would not differ from those obtained 1-3 weeks post-PCI in patients with stable coronary heart disease (CHD). CPET was performed the day after and 1-3 weeks (13±4.6; 7-21 days) after PCI. CPET was performed with a bicycle ergometer up to the ventilatory aerobic threshold (VAT) on the day after PCI. Symptom-limited CPET was conducted 1-3 weeks after PCI. No complications arose from the tests. There were no significant differences in %VAT (next day: 88.6±16.7 vs. 1-3 weeks later: 91.4%±18.7%), the workload at the VAT (51.8±11.0 W vs. 52.9± 11.6 W), heart rate (HR) at the VAT (95.3±105 beats/min vs. 94.1±11.3 beats/min), or metabolic equivalent (METs) at the VAT (3.69±0.69 vs. 3.84±0.78) between the two sessions. The slope of linear regression for two repeated measurements was close to 1 (%VAT, 1.02; workload at the VAT, 0.95; METs at the VAT, 1.03), except for HR (0.70). Bland-Altman plots revealed the reproducibility of all four CPET measurements between the two sessions. In conclusion, CPET up to the VAT can be performed safely 1-day post-PCI in patients with stable CHD. CPET parameters do not significantly differ between testing performed the day after and 1-3 weeks after PCI. Next-day CPET during hospitalization after PCI may enable prompt exercise prescription without the need for another CPET 1-3 weeks later.

Optimal prevention method of phrenic nerve injury in superior vena cava isolation: efficacy of high-power, short-duration radiofrequency energy application on the risk points

BACKGROUND OR PURPOSE

Superior vena cava isolation (SVCI) is widely performed adjunctively to atrial fibrillation (AF) ablation. Right phrenic nerve injury (PNI) is a complication of this procedure. The purpose of the study is to determine the optimal PNI prevention method in SVCI.

METHODS

A total of 1656 patients who underwent SVCI between 2009 and 2022 were retrospectively examined. PNI was diagnosed based on the diaphragm position and movement in the upright position on chest radiographs before and after SVCI.

RESULTS

With the introduction of various PN monitoring systems over the years, the incidence of SVCI-associated PNI has decreased. However, complete PNI avoidance has not been achieved. PNI incidence according to fluoroscopy-guided PN monitoring, high-output pace-guided, compound motor action potential-guided, and 3-dimensional electro-anatomical mapping (EAM) systems was 8.1% (38/467), 2.7% (13/476), 2.4% (4/130), and 2.8% (11/389), respectively. However, a high-power, short-duration (50 W/7 s) radiofrequency (RF) energy application only on PNI risk points tagged by a 3-dimensional EAM system completely avoids PNI (0%; 0 /160 since April 2021). PNI showed no symptoms and recovered within an average of 188 days post-SVCI, except for a few patients who required > 1 year.

CONCLUSIONS

Although PNI incidence decreased annually with the introduction of various monitoring systems, these monitoring systems did not prevent PNI completely. Most notably, the delivery of a high-power, short-duration RF energy only on risk points tagged by EAM prevented PNI completely. PNI recovered in all patients. The application of higher-power, shorter-duration RF energy on risk points tagged by EAM appears to be an optimal PNI prevention maneuver.

Small solitary atrial fractionated electrogram zone as a novel ablation target for persistent atrial fibrillation

INTRODUCTION

Various adjunctive approaches to pulmonary vein isolation (PVI) have been attempted for persistent atrial fibrillation (perAF) and longstanding persistent AF (ls-perAF). We aimed to identify the novel zones responsible for perpetuation of AF.

METHODS

To identify novel zones acting as a source of perAF and ls-perAF after PVI/re-PVI, we performed fractionation mapping in 258 consecutive patients with perAF (n = 207) and ls-perAF (n = 51) in whom PVI/re-PVI failed to restore sinus rhythm.

RESULTS

In 15 patients with perAF (5.8%: 15/258), fractionation mapping identified a small solitary zone (<1 cm² ) with high-frequency and irregular waves, showing fractionated electrograms (EGM). We defined this zone as the small solitary atrial fractionated EGM (SAFE) zone. The small SAFE zone was surrounded characteristically by a homogeneous area showing relatively organized activation with nonrapid and nonfractionated waves. Only one small SAFE zone was detected in each patient. This characteristic electrical phenomenon was observed stably during the procedure until ablation. AF duration, (defined as the duration between initial detection of AF and the current ablation) was longer in patients with the small SAFE zone than in those without (median, [25 and 75 percentiles]; 5.0 [3.5, 7.0] vs. 1.1 [1.0, 4.0] years, p = .0008). Longer AF cycle length was observed in patients with the small SAFE zone than in those without. The ablation of the small SAFE zone terminated AF in all 15 patients without any need for other ablations. AF/atrial tachycardia-free rate at follow-up was 93% (14/15) at 6 months, 87% (13/15) at 1 year, and 60% (9/15) at 2 years.

CONCLUSIONS

Using fractionation mapping, this study identified a small SAFE zone surrounded characteristically by a homogeneous, relatively organized, low-excitability EGM lesion. The ablation of the small SAFE zone terminated AF in all patients, demonstrating it as a substrate for perpetuated AF. Our findings provide novel ablation targets in perAF patients with prolonged AF duration. Further studies to confirm the present results are warranted.

Rates of atrial flutter occurrence and cavotricuspid isthmus reconduction after prophylactic isthmus ablation performed during atrial fibrillation ablation: a clinical study, review, and comparison with previous findings

PURPOSE

Based on the high rate of coexisting atrial fibrillation (AF) and atrial flutter (AFL), prophylactic cavotricuspid isthmus ablation (CTIA) adjunctive to AF ablation has recently been attempted in patients with AF and without AFL. The present study aimed to determine the rates of AFL occurrence and CTI reconduction after performing CTI ablation adjunctive to AF ablation.

METHODS

We analyzed the data of 3833 consecutive patients with AF, who underwent prophylactic CTIA with AF ablation between 2009 and 2020.

RESULTS

In all patients, CTIA and AF ablations were successful. Clinical AFL occurred in seven patients (0.18%, 7/3,833), and the observed rate was lower than those reported for cases of AF ablation without CTIA and for those of CTIA for pure AFL. A second ablation was needed in 745 patients at a median of 253 days (25 and 75 percentiles, 116 and 775 days) after the first ablation. In 12.1% (90/745) of the patients, CTI reconduction was observed. The reconduction rate was lower than that previously reported for CTIA for pure AFL.

CONCLUSIONS

The present retrospective study found acceptably low rates of clinical AFL occurrence and CTI reconduction following prophylactic CTIA performed with AF ablation, which was supported by the findings obtained after performing a comparison of the rates with those of other ablations (AF ablation only and CTIA for pure AFL). Considering the high correlation between AF and AFL, the present study provided information regarding the efficacy of adjunctive CTIA.

Efficacy of an Adjunctive Electrophysiological Test-Guided Left Atrial Posterior Wall Isolation in Persistent Atrial Fibrillation Without a Left Atrial Low-Voltage Area

BACKGROUND

Electrical remodeling precedes structural remodeling. In adjunctive left atrial (LA) low-voltage area (LVA) ablation to pulmonary vein isolation of atrial fibrillation (AF), LA areas without LVA have not been targeted for ablation. We studied the effect of adjunctive LA posterior wall isolation (PWI) on persistent AF without LA-LVA according to electrophysiological testing (EP test).

METHODS

We examined consecutive patients with persistent AF with (n=33) and without (n=111) LA-LVA. Patients without LA-LVA were randomly assigned to EP test-guided (n=57) and control (n=54) groups. In the EP test-guided group, an adjunctive PWI was performed in those with positive results (PWI subgroup; n=24), but not in those with negative results (n=33). The criteria for positive EP tests were an effective refractory period ≤180 ms, effective refractory period>20 ms shorter than the other sites, and/or induction of AF/atrial tachycardia (AT) during measurements. LVA ablation was performed in the patients with LA-LVA.

RESULTS

During the follow-up period (62±33 weeks), the EP test-guided group had significantly lower recurrence rates (19%,11/57 versus 41%, 22/54, P=0.012) and higher Kaplan-Meier AF/AT-free survival curve rates than the control group (P=0.01). No significant differences in the recurrence and AF/AT-free survival curve rates between the PWI (positive EP test) and non-PWI (negative EP test) subgroups were observed. Therefore, PWI for positive EP tests reduced the AF/AT recurrence in the EP test-guided group. A stepwise Cox proportional hazard analyses identified EP test-guided ablation as a factor reducing the recurrence rate. The recurrence rates in the LA-LVA ablation group and EP test-guided group were similar.

CONCLUSIONS

This pilot study proposed that an EP test-guided adjunctive PWI of persistent AF without LA-LVA potentially reduced AF/AT recurrences. The results suggest that there is an AF substrate in the LA with altered electrophysiological function even when there is no LA-LVA. Graphic Abstract: A graphic abstract is available for this article.

Correlation of the peak oxygen consumption and ventilatory aerobic threshold by cardiopulmonary exercise testing with atrial fibrillation recurrences after ablation in patients with paroxysmal atrial fibrillation

Background

The cardiopulmonary function is hypothesized to be associated with atrial fibrillation/atrial tachyarrhythmia (AF/AT) recurrence after AF ablation.

Purpose

To clarify the relationship between the cardiopulmonary function after successful ablation and AF/AT recurrence.

Methods

We examined 31 patients with paroxysmal AF who underwent AF ablation. Cardiopulmonary exercise testing (CPET) was performed at 1month after the ablation. A continuously increasing loading method on a bicycle ergometer was employed for the CPET.

Results

No adverse events, including AF/AT recurrence, occurred during the CPET. Among 31 patients, AT/AF recurrence was observed in seven (23%). The ventilatory anaerobic threshold (VAT) and peak oxygen consumption (VO2) were significantly higher in patients without AF/AT recurrence than in those with AT/AF recurrences (peak VO2 23.6 ± 5.7 vs 17.2 ± 4.1 mL/kg/min; VAT, 16.7 ± 2.8 vs 13.8 ± 2.7 mL/min/kg). The areas under the receiver operating characteristic curve for the peak VO2 and VAT were 0.786 (P < .01) and 0.789(P < .01), respectively. Both indices had a sensitivity of 70%–80% and specificity of 70%–80% for predicting AT/AF recurrence. Similar results were obtained for the percent values of the predicted peak VO2 and VAT.

Conclusions

The present pilot study found that CPET can be performed safely at approximately 1 month after AF ablation. The peak VO2 and VAT were significantly associated with AT/AF recurrence. The peak VO2 and VAT were thought to provide helpful information regarding AT/AF recurrence.

Activated clotting time on the day of atrial fibrillation ablation for minimally interrupted and uninterrupted direct oral anticoagulation therapy: Sequential changes, differences among direct oral anticoagulants, and ablation safety outcomes

Background

Activated clotting time (ACT)–guided heparinization is used during atrial fibrillation (AF) ablation. Differences in sensitivity to ACT assays have been identified among different direct oral anticoagulants (DOACs).

Objective

We aimed to examine ACT just before ablation (pre‐ACT) for different ablation start times (9:00, 11:00, 13:00, or 15:00) and ablation safety outcomes in minimally interrupted (min‐Int) and uninterrupted (Unint) DOAC regimens and examine differences in pre‐ACT values among four DOACs.

Methods

Consecutive patients were randomized into the min‐Int (n = 307) or Unint (n = 277) groups. DOACs examined were apixaban, dabigatran, edoxaban, and rivaroxaban.

Results

No sequential changes in pre‐ACT values were observed for each DOAC used and for all four DOACs combined in the min‐Int and Unint groups. There was no meaningful difference in pre‐ACT at each ablation start time between the groups. Clinically significant differences in overall pre‐ACT were not obtained between the groups (138 ± 24 vs 142 ± 23 seconds). The pre‐ACT (baseline) value for dabigatran was on average 29 seconds higher than that for the other three DOACs. The min‐Int and Unint groups showed similar thromboembolic (0% vs 0%) and bleeding event rates (major, 1% vs 0%; all, 3.5% vs 2.5%).

Conclusion

The pre‐ACT did not show a sequential change in the min‐Int and Unint groups. No notable differences in the time‐dependent change in pre‐ACT between the groups were observed. Variations in baseline ACT suggest the need for moderate adjustment of ACT for adequate modification of heparin dose for the other three DOACs. Both regimens provided similar acceptable AF ablation safety outcomes.

A High-Fat and High-Cholesterol Diet Induces Cardiac Fibrosis, Vascular Endothelial, and Left Ventricular Diastolic Dysfunction in SHRSP5/Dmcr Rats

AIM

Non-alcoholic steatohepatitis (NASH) increases cardiovascular risk regardless of risk factors in metabolic syndrome. However, the intermediary factors between NASH and vascular disease are still unknown because a suitable animal model has never been established. The stroke-prone (SP) spontaneously hypertensive rat, SHRSP5/Dmcr, simultaneously develops hypertension, acute arterial lipid deposits in mesenteric arteries, and NASH when feed with a high-fat and high-cholesterol (HFC) diet. We investigated whether SHRSP5/Dmcr affected with NASH aggravates the cardiac or vascular dysfunction.

METHOD

Wister Kyoto and SHRSP5/Dmcr rats were divided into 4 groups of 5 rats each, and fed with a SP or HFC diet. After 8 weeks of HFC or SP diet feeding, glucose and insulin resistance, echocardiography, blood biochemistry, histopathological staining, and endothelial function in aorta were evaluated.

RESULTS

We demonstrate that SHRSP5/Dmcr rats fed with a HFC diet presented with cardiac and vascular dysfunction caused by cardiac fibrosis, endothelial dysfunction, and left ventricular diastolic dysfunction, in association with NASH and hypertension. These cardiac and vascular dysfunctions were aggravated and not associated with the presence of hypertension, glucose metabolism disorder, and/or obesity.

CONCLUSIONS

SHRSP5/Dmcr rats may be a suitable animal model for elucidating the organ interaction between NASH and cardiac or vascular dysfunction.

Adjunctive interpulmonary isthmus ablation has no added effects on atrial fibrillation recurrence

Objective

Data on the efficacy of adjunctive interpulmonary isthmus ablation following completion of extensive encircling pulmonary vein isolation (EEPVI) on atrial fibrillation (AF) recurrence have still been insufficient. We aimed to compare the AF recurrence between EEPVI with and without adjunctive interpulmonary isthmus ablation.

Methods

We enrolled 200 consecutive patients with paroxysmal AF (first session) who underwent EEPVI with double-Lasso technique. Patients were prospectively randomised into two groups: EEPVI with (group 1) and without (group 2) adjunctive interpulmonary isthmus ablation.

Results

No differences were found in patients’ clinical and echocardiographic backgrounds, including arrhythmia status, between the two groups. No differences were also observed in complications (two groin haematoma in both groups). All patients in both groups reached the EEPVI endpoint. The AF recurrence rate between groups 1 (32/100, 32%) and 2 (33/100, 33%; p=1.0) was quite similar during the follow-up period (45±5 months; 36–54 months). The two groups showed identical Kaplan-Meier AF-free curves (p=0.460; NS). Similar pulmonary vein (PV) reconnection incidence was observed in both groups during the second session. Durable isolation between the superior and inferior PVs was confirmed in 88% (21/27) of patients in group 1, indicating that interpulmonary isthmus ablation maintained a non-conducting state in a considerable number of patients. Nevertheless, AF recurrence was identical between the two groups.

Conclusion

The results of our study showed similar AF recurrence rates between the two groups, indicating that adjunctive interpulmonary isthmus ablation with EEPVI has no obvious effects on AF recurrence.

ADAMTS1 inhibits lymphangiogenesis by attenuating phosphorylation of the lymphatic endothelial cell-specific VEGF receptor

Angiogenesis and lymphangiogenesis play roles in malignant tumor progression, dissemination, and metastasis. ADAMTS1, a member of the matrix metalloproteinase family, is known to inhibit angiogenesis. Recombinant ADAMTS1 was shown to strongly inhibit angiogenesis. We investigated whether ADAMTS1 inhibited lymphangiogenesis in the present study. We examined cell proliferation and cell migration in normal human dermal lymphatic microvascular endothelial cells (HMVEC-dLy) transduced with or without adenoviral human ADAMTS1 gene therapy. We then examined the VEGFC/VEGFR3 signal transduction pathway in ADAMTS1-transduced HMVEC-dLy. Cell proliferation and tube formation in Matrigel were significantly lower with transduced ADAMTS1 than with control (non-transduced HMVEC-dLy). The phosphorylation of VEGFR3 was also attenuated by ADAMTS1 gene therapy in HMVEC-dLy. Immunoprecipitation assays revealed that ADAMTS1 formed a complex with VEGFC. Our results demonstrated that ADAMTS1 inhibited lymphangiogenesis in vitro. The data highlight the new function of ADAMTS1 in the regulation of lymphangiogenesis and the therapeutic potential of ADAMTS1 in cancer therapy.

Usefulness of dabigatran etexilate as periprocedural anticoagulation therapy for atrial fibrillation ablation

BACKGROUND

The usefulness of dabigatran etexilate for the prevention of stroke in patients with atrial fibrillation (AF) has been reported.

OBJECTIVES

In this study the efficacy and safety of dabigatran etexilate for anticoagulation for AF ablation were examined.

METHOD

Patients were divided into three groups: Group 1, interrupted warfarin bridged by heparin between pre- and post-ablation; Group 2, continuous warfarin therapy; and Group 3, dabigatran etexilate therapy. Anticoagulation therapy with warfarin or dabigatran etexilate was performed from 30 days before to at least 90 days after AF ablation. Dabigatran etexilate was administered at 110 or 150 mg twice daily, depending on renal function and age.

RESULTS

Patients' clinical characteristics, associated disorders, echocardiographic parameters and arrhythmia status were not different among the three groups. Procedural parameters such as procedural time and radiofrequency energy supply were also not different among the three groups. The dabigatran etexilate group and the warfarin groups had no embolic complications (stroke, cerebral transient ischaemic attack, deep venous thrombosis or pulmonary embolism). No pericardial tamponade was observed in the dabigatran etexilate group, while two patients in each of Group 1 (2/194, 1.0 %) and Group 2 (2/203, 0.98 %) developed cardiac tamponade, though the differences were not significant. Pericardial effusion and groin haematoma were observed in one patient each (1/105, 0.9 %) in the dabigatran etexilate group, and the incidences were not different from the warfarin group (Group 1: 4/194, 2.1 % and 2/194, 1.0 %; Group 2: 3/203, 1.5 % and 2/203, 1.0 %, respectively). As a whole, the safety outcomes did not differ among the three groups.

CONCLUSION

Dabigatran etexilate is an effective and safe anticoagulation therapy for AF ablation. Thus, dabigatran etexilate appears to be useful as an alternative anticoagulant therapy to warfarin for AF ablation.

Adaptive-servo ventilation combined with deep sedation is an effective strategy during pulmonary vein isolation

AIMS

Pulmonary vein isolation (PVI) by catheter ablation for atrial fibrillation (AF) requires suppression of patient restlessness by sufficient sedation in addition to maintaining stable respiration. We applied adaptive-servo ventilation (ASV) and examined the effects of ASV combined with deep propofol sedation on PVI using a NavX.

METHODS AND RESULTS

We analysed 75 paroxysmal AF (PAF) patients (62 ± 11 years; 53 men and 22 women) who underwent PVI for treatment of PAF using an ASV system combined with deep sedation (ASV group). Control patients included 75 consecutive PAF patients (62 ± 11 years; 51 men and 24 women) who underwent PVI just before introduction of the ASV system. Deep sedation was defined as a Ramsay sedation score of 6. The ASV group had a lower frequency of restless body movements compared with the control group during PVI (1.5 ± 0.7 vs. 7.8 ± 1.4 times, P < 0.01). The frequency of respiratory compensation and EnGuide alignment of catheter position by the NavX was lower in the ASV (4.2 ± 3.3 and 8.8 ± 7.1 times) than control group (7.1 ± 5.1 and 15.2 ± 10.0 times, P < 0.05 and <0.01, respectively). Consequently, significantly lower total electrical energy supply (48.7 ± 6.0 KJ) was required in the ASV than control group (64.5 ± 24.9 KJ, P < 0.01). Further, significantly shorter fluoroscopy and procedural times were observed in the ASV (28 ± 5 and 109 ± 25 min) than the control group (33 ± 6 and 141 ± 38 min, respectively, P < 0.01) and the AF recurrence rate was significantly lower in the ASV than the control group (12 vs. 25%, P < 0.01).

CONCLUSION

ASV combined with deep sedation is an effective strategy during PVI using the NavX in patients with PAF.

Tumor growth inhibitory effect of ADAMTS1 is accompanied by the inhibition of tumor angiogenesis

Angiogenesis plays an important role in tumor progression. Several reports have demonstrated that a disintegrin and metalloproteinase with thrombospondin motifs1 (ADAMTS1) inhibited angiogenesis via multiple mechanisms. The aim of this study was to investigate the effect of ADAMTS1 on endothelial cells in vitro and on tumor growth with regard to angiogenesis in vivo. We examined the effects of the transfection of ADAMTS1 using two constructs, full-length ADAMTS1 (full ADAMTS1) and catalytic domain-deleted ADAMTS1 (delta ADAMTS1). Transfection of both the full ADAMTS1 and delta ADAMTS1 gene constructs demonstrated the secretion of tagged-ADAMTS1 protein into the conditioned medium, so we examined the effects of ADAMTS1-containing conditioned medium on endothelial cells. Both types of conditioned media inhibited endothelial tube formation, and this effect was completely abolished after immunoprecipitation of the secreted protein from the medium. Both types of conditioned media also inhibited endothelial cell migration and proliferation. We then examined the impact of ADAMTS1 on endothelial cell apoptosis. Both conditioned media increased the number of Annexin V-positive endothelial cells and caspase-3 activity and this effect was attenuated when z-vad was added. These results indicated that ADAMTS1 induced endothelial cell apoptosis. We next examined the effects of ADAMTS1 gene transfer into tumor-bearing mice. Both full ADAMTS1 and delta ADAMTS1 significantly inhibited the subcutaneous tumor growth. Collectively, our results demonstrated that ADAMTS1 gene transfer inhibited angiogenesis in vitro and in vivo, likely as a result of the induction of endothelial cell apoptosis by ADAMTS1 that occurs independent of the protease activity.

Bral2 is indispensable for the proper localization of brevican and the structural integrity of the perineuronal net in the brainstem and cerebellum

Perineuronal nets (PNNs) are pericellular coats of condensed matrix that enwrap the cell bodies and dendrites of many adult central nervous system (CNS) neurons. These extracellular matrices (ECMs) play a structural role as well as instructive roles in the control of CNS plasticity and the termination of critical periods. The cartilage link protein Crtl1/Hapln1 was reported to be a trigger for the formation of PNNs in the visual cortex. Bral2/Hapln4 is another link protein that is expressed in PNNs, mainly in the brainstem and cerebellum. To assess the role of Bral2 in PNN formation, we examined the expression of PNN components in targeted mouse mutants lacking Bral2. We show here that Bral2-deficient mice have attenuated PNNs, but the overall levels of chondroitin sulfate proteoglycans, lecticans, are unchanged with the exception of neurocan. Bral2 deficiency markedly affected the localization of brevican in all of the nuclei tested, and neurocan concomitant with Crtl1 in some of the nuclei, whereas no effect was seen on aggrecan even with the attenuation of Crtl1. Bral2 may have a role in the organization of the PNN, in association with brevican, that is independent of aggrecan binding. There was a heterogenous attenuation of PNN components, including glycosaminoglycans, indicating the elaborate molecular organization of the PNN components. Strikingly, a slight decrease in the number of synapses in deep cerebellar nuclei neurons was found. Taken together, these results imply that Bral2-brevican interaction may play a key role in synaptic stabilization and the structural integrity of the PNN.

Elevated serum adipocyte fatty acid-binding protein concentrations are independently associated with renal dysfunction in patients with stable angina pectoris

Background

Chronic kidney disease (CKD) is associated with cardiovascular events. Adipocyte fatty acid-binding protein (A-FABP) plays an important role in atherosclerosis. We investigated whether plasma A-FABP is involved in renal function in patients with stable angina pectoris.

Methods

A total of 221 patients with significant coronary artery stenosis were enrolled after coronary angiography. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m². The severity of coronary stenosis was assessed using a modified Gensini score and coronary angiography. Serum A-FABP levels were determined by enzyme-linked immunosorbent assay.

Results

Serum A-FABP levels were significantly correlated with both eGFR (r = -0.41, p < 0.01) and the severity of coronary artery stenosis (r = 0.16, p = 0.02), and these relationships remained significant after adjusting for confounding factors. The prevalence of CKD and multi-vessel disease was significantly higher among patients with serum A-FABP levels above the median value of 20.3 ng/ml than among patients with serum A-FABP levels below the median value (57% vs. 27%, p < 0.01 and 64% vs. 48%, p = 0.02, respectively). Multivariate analysis revealed that the presence of three-vessel disease in comparison with single-vessel disease was independently associated with the higher A-FABP (per doubling) (odds ratio; 2.26, 95% confidential interval; 1.28-3.98, p < 0.01) and tended to be associated with the lower eGFR (p = 0.06).

Conclusion

Serum A-FABP may have a significant role in the interplay between renal dysfunction and coronary atherosclerosis.

Four-year clinical outcomes of the OLIVUS-Ex (impact of Olmesartan on progression of coronary atherosclerosis: evaluation by intravascular ultrasound) extension trial

BACKGROUND

The previous OLIVUS trial reported a positive role in achieving a lower rate of coronary atheroma progression through the administration of olmesartan, an angiotension-II receptor blocking agent (ARB), for stable angina pectoris (SAP) patients requiring percutaneous coronary intervention (PCI). However, the benefits between ARB administration on long-term clinical outcomes and serial atheroma changes by IVUS remain unclear. Thus, we examined the 4-year clinical outcomes from OLIVUS according to treatment strategy with olmesartan.

METHODS

Serial volumetric IVUS examinations (baseline and 14 months) were performed in 247 patients with hypertension and SAP. When these patients underwent PCI for culprit lesions, IVUS was performed in their non-culprit vessels. Patients were randomly assigned to receive 20-40mg of olmesartan or control, and treated with a combination of β-blockers, calcium channel blockers, glycemic control agents and/or statins per physician's guidance. Four-year clinical outcomes and annual progression rate of atherosclerosis, assessed by serial IVUS, were compared with major adverse cardio- and cerebrovascular events (MACCE).

RESULTS

Cumulative event-free survival was significantly higher in the olmesartan group than in the control group (p=0.04; log-rank test). By adjusting for validated prognosticators, olmesartan administration was identified as a good predictor of MACCE (p=0.041). On the other hand, patients with adverse events (n=31) had larger annual atheroma progression than the rest of the population (23.8% vs. 2.1%, p<0.001).

CONCLUSIONS

Olmesartan therapy appears to confer improved long-term clinical outcomes. Atheroma volume changes, assessed by IVUS, seem to be a reliable surrogate for future major adverse cardio- and cerebrovascular events in this study cohort.

Association of increased plasma adipocyte fatty acid-binding protein with coronary artery disease in non-elderly men

Background

Adipocyte fatty acid-binding protein (A-FABP) has been reported to play critical roles in the development of atherosclerosis. We investigated whether an increased in plasma A-FABP level can be independently associated with the presence of coronary artery disease (CAD).

Methods

Two hundred eleven consecutive male patients (mean age: 66 years, range: 33-87 years) were enrolled from inpatients who underwent coronary angiography. Age-matched male subjects (n = 211) having no evidence of CAD served as controls. Plasma A-FABP levels were measured by enzyme-linked immunosorbent assays.

Results

Plasma A-FABP levels in CAD patients were significantly higher than in control subjects (median [IQR], 20.6 [15.7-27.8] ng/mL vs. 15.1 [11.7-19.9] ng/mL, p < 0.01). Multivariate logistic regression analysis revealed that an increased plasma A-FABP level was independently associated with the presence of CAD in all subjects (adjusted odds ratio: 1.76, 95% confidence interval: 1.14 to 2.70, p = 0.01). Furthermore, sub-analysis based on age showed that this association remained significant in subjects aged < 65 years (adjusted odds ratio: 3.06, 95% confidence interval: 1.34 to 6.98, p < 0.01), but not in subjects aged ≥65 years.

Conclusions

Increased plasma A-FABP in non-elderly men had a significant association with the presence of CAD, independent of established CAD risk factors.

Association of circulating levels of leptin and adiponectin with metabolic syndrome and coronary heart disease in patients with various coronary risk factors

The aim of this study was to investigate the associations of adiponectin and leptin with metabolic syndrome (MetS) and coronary heart disease (CHD) in patients with various coronary risk factors. We determined serum adiponectin, leptin, and metabolic syndrome components in 104 patients (59 men and 45 women; aged 40-86 years) with various coronary risk factors at a cardiovascular out-patient clinic. Natural logarithmic transformed (ln) leptin was lower in men and smokers, and positively correlated with body mass index (BMI) (r = 0.59, P < 0.0001), waist circumference (r = 0.60, P < 0.0001), and homeostasis model assessment of insulin resistance (HOMA-IR) levels (r = 0.24, P < 0.02). Ln adiponectin was higher in women and nonsmokers, and was correlated with age and high-density lipoprotein cholesterol (HDL-C). Patients with MetS (n = 69) had significantly higher BMI, HOMA-IR, and ln leptin and lower ln adiponectin than those without Mets (Ln leptin, 2.14 ± 0.08 versus 1.30 ± 0.11; Ln adiponectin, 2.29 ± 0.06 versus 2.54 ± 0.09). In contrast, patients with coronary heart disease (CHD: n = 40) had significantly lower serum ln adiponectin concentrations than non-CHD patients (n = 64) (1.79 ± 0.12 versus 1.91 ± 0.10) as well as lower HDL-C and a higher smoking percentage. Consistent results were obtained by multivariate analyses. In conclusion, this study disclosed factors associated with the increase in serum leptin and adiponectin. Serum levels of leptin may be associated positively with MetS, whereas adiponectin levels are associated negatively with MetS and CHD, even in patients with various coronary risk factors.

Distribution of α(IV) collagen chains in the ocular anterior segments of adult mice

The distribution of the collagen chains from α1(IV) to α6(IV) could serve as a basis for the characterization of type IV collagen. In this study, immunohistochemistry of the ocular anterior segment of adult mice was performed using specific monoclonal antibodies against each chain in the series from α1(IV) to α6(IV). The results show that the components of type IV collagen in vascular basement membranes are α1(IV) and α2(IV) with or without α5(IV) and α6(IV) chains and those in epithelium and muscle basement membranes are α1(IV), α2(IV), α5(IV), and α6(IV) chains. In corneal endothelium, pigmented epithelium of iris and ciliary body, and trabecular meshwork, α3(IV) and α4(IV) chains are also expressed in addition to α1(IV), α2(IV), α5(IV), and α6(IV) chains. Moreover, we investigated the change in molecular composition in ciliary body during postnatal development. α3(IV) and α4(IV) chains were also expressed in addition to α1(IV), α2(IV), α5(IV), and α6(IV) chains in ciliary pigmented epithelium basement membrane from 7 days after birth. This result suggests that the basement membranes gradually change their biochemical features owing to temporal regulation. Taken together, these findings suggest that the different distribution and the developmental expression of α1(IV) to α6(IV) chains are associated with the tissue-specific function of type IV collagen in basement membranes.

QT Dispersion Measured by Automatic Computerized 12-Lead Electrocardiography Contributes Significantly to Detection of Left Ventricular Hypertrophy in Japanese Patients

This study assessed the diagnostic value of QT dispersion for left ventricular hypertrophy (LVH) as determined by echocardiography. The QT and QRS interval parameters were determined automatically using computerized 12-lead electrocardiography in 153 Japanese outpatients. Corrected QT dispersion (QTcD) and maximal QRS duration (MaxQRS) were significantly correlated with left ventricular mass index. The sum of QTcD and MaxQRS showed the highest correlation with left ventricular mass index among QT and QRS interval parameters and their combinations. The cut-off points for LVH discrimination in this study were different to those reported in Western, mainly Caucasian, populations, suggesting the need for ethnicity-specific LVH detection criteria. A scoring system derived from multiple logistic regression analysis, employing a combination of QTcD, QRS time–voltage product and ST-T change, showed a specificity of 86.3%. It was concluded that QTcD, in addition to QRS time–voltage product and ST-T change, improved the detection of LVH.

Distribution pattern of urine albumin creatinine ratio and the prevalence of high-normal levels in untreated asymptomatic non-diabetic hypertensive patients

BACKGROUND

Even high-normal albuminuria is reportedly associated with cardiovascular events.

OBJECTIVE

We determined the urine albumin creatinine ratio (UACR) in spot urine samples and analyzed the UACR distribution and the prevalence of high-normal levels.

PATIENTS AND METHODS

The UACR was determined using immunoturbidimetry in 332 untreated asymptomatic non-diabetic Japanese patients with hypertension and in 69 control subjects. The microalbuminuria and macroalbuminuria levels were defined as a UCAR ≥30 and <300 µg/mg·creatinine and a UCAR ≥300 µg/mg·creatinine, respectively.

RESULTS

The distribution patterns showed a highly skewed distribution for the lower levels, and a common logarithmic transformation produced a close fit to a Gaussian distribution with median, 25th and 75th percentile values of 22.6, 13.5 and 48.2 µg/mg·creatinine, respectively. When a high-normal UACR was set at >20 to <30 µg/mg·creatinine, 19.9% (66/332) of the hypertensive patients exhibited a high-normal UACR. Microalbuminuria and macroalbuminuria were observed in 36.1% (120/336) and 2.1% (7/332) of the patients, respectively. UACR was significantly correlated with the systolic and diastolic blood pressures and the pulse pressure. A stepwise multivariate analysis revealed that these pressures as well as age were independent factors that increased UACR.

CONCLUSION

The UACR distribution exhibited a highly skewed pattern, with approximately 60% of untreated, non-diabetic hypertensive patients exhibiting a high-normal or larger UACR. Both hypertension and age are independent risk factors that increase the UACR. The present study indicated that a considerable percentage of patients require anti-hypertensive drugs with antiproteinuric effects at the start of treatment.

Olmesartan reduces arterial stiffness and serum adipocyte fatty acid-binding protein in hypertensive patients

Adipocyte fatty acid binding protein (A-FABP) has been reported to be involved in insulin resistance, lipid metabolism, and atherosclerosis; however, little is known about the effect of medication on the change in circulating A-FABP in human subjects. We evaluated the effects of angiotensin II type 1 receptor blocker (ARB) on arterial stiffness and its association with serum A-FABP in patients with hypertension. Thirty patients newly diagnosed with essential hypertension were treated with olmesartan (20 mg/day), an ARB, for 6 months. Serum levels of A-FABP and high-sensitivity C-reactive protein (hsCRP) were examined and the cardio-ankle vascular index (CAVI), which is a marker of arterial stiffness, was also determined. Serum A-FABP at baseline was significantly correlated with the body mass index (r = 0.45, P = 0.01), homeostasis model assessment as a marker of insulin resistance (r = 0.53, P < 0.01), and systolic blood pressure (r = 0.37, P = 0.047), and tended to be correlated with low-density lipoprotein cholesterol, triglyceride, and CAVI. Olmesartan treatment resulted in a significant decrease in CAVI, serum A-FABP levels, and hsCRP, besides a significant reduction of blood pressure. Multiple regression analysis revealed that the change in CAVI was independently correlated with the change in serum A-FABP. Olmesartan ameliorated arterial stiffness in patients with hypertension, which may be involved in the reduction of serum A-FABP.

Association of serum levels of arachidonic acid and eicosapentaenoic acid with prevalence of major adverse cardiac events after acute myocardial infarction

We studied the association of serum levels of arachidonic acid (AA) and eicosapentaenoic acid (EPA) with the prevalence of major adverse cardiac events (MACE) after acute myocardial infarction (AMI). We measured serum AA and EPA on admission in 146 consecutive AMI patients. The primary clinical endpoint was occurrence of MACE, defined as cardiac death, occurrence of heart failure, reinfarction, recurrent angina pectoris, and requirement of coronary intervention. Common logarithmic transformed serum levels of AA (logAA) and EPA (logEPA) were used in the analyses. The optimum cutoff point of each fatty acid used to distribute patients into two groups for Kaplan-Meier analysis was determined by receiver operating characteristic curves analysis. MACE occurred in 40 patients (27.4%). Kaplan-Meier analysis disclosed that the group with a logAA above the cutoff point [145.3 μg/mL (logAA 2.162)] showed a higher prevalence of MACE than those with a logAA below the cutoff point (P < 0.01). Conversely, the prevalence of MACE was significantly higher in the group with a logEPA below the cutoff point [52.3 μg/mL (logEPA 1.719)] compared to the group with a logEPA above it (P < 0.01). Similar to logAA, logAA/logEPA showed significant differences in the MACE-free curve between the two groups (cutoff 1.301, P < 0.001). Cox proportional hazards regression analysis suggested that logAA, logEPA, and logAA/logEPA were independently associated with the prevalence of MACE. Although the present study included a limited number of patients with single-time point measurement, the results suggested an association of logAA, logEPA, and logAA/logEPA with the prevalence of MACE after AMI. The present study warrants further studies involving a large number of patients to confirm that the serum levels of these fatty acids and their ratios are predictors of MACE after AMI.

Inverse correlation between seasonal changes in home blood pressure and atmospheric temperature in treated-hypertensive patients

We examined the relationships between home blood pressure (BP) and atmospheric temperature in 20 treated-hypertensive patients. A significant correlation between morning and evening BP and atmospheric temperature was found. For morning systolic blood pressure (SBP), the maximal seasonal difference was 13.2 mmHg with 25.5 degrees C temperature difference. Morning SBP increased by approximately 0.41 mmHg with a 1 degrees C decrease in atmospheric temperature. A similar but weaker correlation with temperature was observed for morning diastolic, evening systolic and diastolic blood pressure (DBP). The present study provides important information in respect to BP changes with atmospheric temperature that should be taken into account in the analysis and treatment of hypertension.

Effect of cilnidipine on normal to marginally elevated urine albumin-creatinine ratio in asymptomatic non-diabetic hypertensive patients: an exponential decay curve analysis

BACKGROUND

High-normal urinary albumin excretion has been reported to have clinical significance with respect to progression of proteinuria and hypertension.

OBJECTIVE

We analysed the effect of cilnidipine (10 mg/day) on morning systolic blood pressure (SBP) and urine albumin-creatinine ratio (UACR) in 16 non-diabetic hypertensive patients with a normal to marginally elevated UACR (mean +/- SD 29.4 +/- 21.7; range 7.5-72.9 mg/g creatinine).

METHODS

Sequential home BP and UACR data were fitted to a simple exponential function as follows: where y is SBP (mmHg) or UACR (mg/g creatinine); alpha is the extent of the SBP (mmHg)- or UACR (mg/g creatinine)-lowering effect; beta (days) is the time-constant for SBP or UACR decrease; t is the number of days after the start of cilnidipine administration; and gamma is the finally stabilized SBP (mmHg) or UACR (mg/g creatinine).

RESULTS

Mean +/- SD morning SBP and UACR decreased by 20.4 +/- 11.4 mmHg and 15.2 +/- 13.1 mg/g creatinine, respectively, as determined by coefficient alpha. The mean +/- SD time-constant for UACR decrease was significantly longer than that for BP decrease (43.5 +/- 22.9 vs 15.4 +/- 7.1 days). UACR reduction correlated with pre-treatment UACR values (correlation coefficient [R] = 0.88, p < 0.01) but not with BP decrease.

CONCLUSIONS

The present study demonstrated that cilnidipine reduced UACR in hypertensive patients with normal to marginally elevated UACR independent of its BP-lowering effect.

Impact of olmesartan on progression of coronary atherosclerosis a serial volumetric intravascular ultrasound analysis from the OLIVUS (impact of OLmesarten on progression of coronary atherosclerosis: evaluation by intravascular ultrasound) trial

OBJECTIVES

The aim of this study was to evaluate the impact of olmesartan on progression of coronary atherosclerosis.

BACKGROUND

Prior intravascular ultrasound (IVUS) trial results suggest slowing of coronary atheroma progression with some medicines but have not shown convincing evidence of regression with angiotension-II receptor blocking agents.

METHODS

A prospective, randomized, multicenter trial-OLIVUS (Impact of OLmesartan on progression of coronary atherosclerosis: evaluation by IntraVascular UltraSound)-was performed in 247 stable angina pectoris patients with native coronary artery disease. When these patients underwent percutaneous coronary intervention for culprit lesions, IVUS was performed in their nonculprit vessels (without angiographically documented coronary stenosis [<50%]). Patients were randomly assigned to receive 10 to 40 mg of olmesartan or control and treated with a combination of beta-blockers, calcium channel blockers, diuretics, nitrates, glycemic control agents, and/or statins per physician's guidance. Serial IVUS examinations (baseline and 14-month follow-up) were performed to assess coronary atheroma volume. Volumetric IVUS analyses included lumen, plaque, vessel volume, percent atheroma volume (PAV), percent change in total atheroma volume (TAV) and PAV.

RESULTS

Patient characteristics and blood pressure control were identical between the 2 groups. However, follow-up IVUS showed significantly decreased TAV and percent change in PAV in the olmesartan group (5.4% vs. 0.6 % for TAV and 3.1% vs. -0.7% for percent change in PAV, control vs. olmesartan, p < 0.05 for all).

CONCLUSIONS

These observations suggest a positive role in a potentially lower rate of coronary atheroma progression through the administration of olmesartan, an angiotension-II receptor blocking agent, for patients with stable angina pectoris.

Filtered QRS duration on signal-averaged electrocardiography correlates with ventricular dyssynchrony assessed by tissue Doppler imaging in patients with reduced ventricular ejection fraction

OBJECTIVES

The relationships between filtered QRS duration and ventricular dyssynchrony were studied.

METHODS

We measured filtered QRS duration on signal-averaged electrocardiography and analyzed tissue Doppler imaging in chronic heart failure patients with ejection fraction less than 50%.

RESULTS

In 64 patients, interventricular and intraventricular dyssynchronies were observed in 25 and 38 patients, respectively. All patients with interventricular dyssynchrony were associated with intraventricular dyssynchrony. Filtered QRS showed 0.82 and 0.78 of the area under the curve (AUC) in the receiver operating characteristic curve (ROC) for the detection of interventricular and intraventricular dyssynchrony, respectively, with 89.7% and 96.2% specificity and 52.0% and 52.6% sensitivity, with cutoff values of 174 and 153 milliseconds. Specificity and sensitivity as well as AUC were lower in the ROC of QRS duration than filtered QRS duration.

CONCLUSION

Filtered QRS duration provided more reliable information to estimate ventricular dyssynchrony in patients with reduced ventricular ejection fraction than QRS duration did.

Cardio-ankle vascular index is independently associated with the severity of coronary atherosclerosis and left ventricular function in patients with ischemic heart disease

AIM

The cardio-ankle vascular index (CAVI) has been proposed as a new noninvasive marker of arterial stiffness independent of blood pressure. We investigated the association of the CAVI with coronary atherosclerosis and left ventricular (LV) systolic and diastolic function in patients with ischemic heart disease (IHD).

METHODS

A total of 206 consecutive subjects undergoing coronary angiography were enrolled. CAVI measurement and echocardiography were performed simultaneously. Patients having significant coronary stenosis were classified into the IHD group.

RESULTS

CAVI in the IHD group (n=133) was significantly higher than in the non-IHD group(n=73)(9.1+/-1.3 vs. 8.7+/-1.2, p=0.02). In all IHD patients, CAVI was negatively correlated with LV ejection fraction (LVEF)(r=-0.31, p<0.01), LV mass index (r=0.24, p<0.01) and angiographic scores of coronary atherosclerosis. Stepwise regression analysis revealed that CAVI was independently associated with LVEF, along with a history of myocardial infarction, LV mass index, and left atrial diameter in all IHD patients (p<0.01). In the sub-analysis of IHD patients with preserved LVEF, CAVI was correlated with echocardiographic parameters regarding LV diastolic function. Multivariate analysis demonstrated that the increased CAVI was significantly associated with LV diastolic dysfunction in patients with preserved LVEF.

CONCLUSION

CAVI, a new parameter of aortic stiffness, was independently associated with LV systolic and diastolic function as well as coronary artery disease in IHD patients.

Coronary pressure measurement based decision making for percutaneous coronary intervention

The fractional flow reserve (FFR) is a simple, reliable, and reproducible physiologic index of lesion severity. In patients with intermediate stenosis, FFR≥0.75 can be used to safely defer percutaneous coronary intervention (PCI), and patients with FFR≥0.75 have a very low cardiac event rate. Coronary pressure measurement can determine which lesion should be treated with PCI in patients with tandem lesions, and PCI on the basis of FFR has been demonstrated to result in an acceptably low repeat PCI rate. FFR can identify patients with equivocal left main coronary artery disease who benefit from coronary bypass surgery. Coronary pressure measurement distinguishes patients with an abrupt pressure drop pattern from those with a gradual pressure drop pattern, and the former group of patients benefit from PCI. Coronary pressure measurement is clinically useful in evaluating sufficient recruitable coronary collateral blood flow for prevention of ischemia, which affects future cardiac events. FFR is useful for the prediction of restenosis after PCI. As an end-point of PCI, FFR ≥0.95 and ≥0.90 would be appropriate for coronary stenting and coronary angioplasty, respectively. In summary, if you encounter a coronary stenosis in doubt you should measure pressure rather than dilate it.

Prone position is essential for detection of pulmonary vein pseudostenosis by enhanced multidetector computed tomography in patients who undergo pulmonary vein isolation

BACKGROUND

Pulmonary vein (PV) stenosis is a major complication of PV isolation (PVI) by catheter ablation, so in the present study the optimal position for detecting PV stenosis on enhanced multidetector computed tomography (MDCT) image acquisition was determined.

METHODS AND RESULTS

The 64-slice enhanced MDCT was carried out before and after PVI in 116 consecutive patients with atrial fibrillation while they were in the prone position, as well as while supine. The supine position MDCT image showed >50% diameter stenosis of the PV in 11 (9%) patients before PVI (% diameter stenosis: mean 55+/-4%, range 51-65%). Greater than 50% diameter stenosis was seen in the left inferior PV in all 11 patients. The prone position attenuated the PV stenosis findings in the MDCT images in all 11 patients (mean 9+/-6%, range 2-18%). Stenosis visualized on images acquired in the supine position was, therefore, concluded to be pseudostenosis caused by descending aorta compression. At 3 months after PVI, no significant changes in PV diameter were observed in these 11 patients.

CONCLUSION

The present study demonstrated that the prone position is essential for eliminating PV pseudostenosis observed on supine-position enhanced MDCT images. The results also indicate that preexisting PV organic stenosis is rare.

The 3'-untranslated region of ADAMTS1 regulates its mRNA stability

ADAMTS1 (a disintegrin and metalloproteinase with thrombospondin motifs 1) is an inflammatory-induced gene. We have previously reported that ADAMTS1 was strongly but transiently expressed in the infarcted heart. In this study, we investigated whether a 3'-untranslated region (UTR) affects the mRNA stability of this gene. When stimulated with tissue necrosis factor (TNF)-alpha, the expression level of ADAMTS1 mRNA rapidly increased, but the induction of ADAMTS1 mRNA peaked at 6h after stimulation, after which the expression levels of ADAMTS1 mRNA decreased. The 3'-UTR ADAMTS1 mRNA contains multiple adenine and uridine-rich elements, suggesting that the 3'-UTR may regulate gene stability. The addition of actinomycin D, an RNA synthesis inhibitor, demonstrated the decay of induced ADAMTS1 mRNA by TNF-alpha. Furthermore, a region containing multiple AUUUA motifs within the ADAMTS1 3'-UTR destabilized transfected Enhanced Green Fluorescence Protein (EGFP) mRNA expression. These results demonstrated that the ADAMTS1 3'-UTR may regulate the expression of ADAMTS1 mRNA.

Abnormal transmural repolarization process in patients with Brugada syndrome

BACKGROUND

Repolarization abnormality, especially during bradycardia, might be critical for initiation of ventricular fibrillation (VF) in patients with Brugada syndrome (BrS), but the contribution of the rate-dependent repolarization dynamics to the occurrence of VF is still unknown.

OBJECTIVE

The aim of our study was to determine the differences in rate-dependent repolarization dynamics between BrS with and without spontaneous VF and between BrS with and without SCN5A mutation.

METHODS

The subjects were 37 BrS patients with VF (VF(+) group: 10 male subjects) and without VF (VF(-) group: 27 male subjects) and 20 control subjects. Genetic analysis of SCN5A was performed in all 37 BrS patients. The relationships between QT, QTp, Tp-e, and RR intervals were obtained from Holter recordings as first linear regression lines, and the slopes of QT/RR, QTp/RR, and Tp-e/RR linear regression lines as the sensitivity of rate-dependent repolarization dynamics were compared.

RESULTS

QT/RR and Tp-e/RR slopes showed loss of a rate-dependent property in the VF(+) group compared with those in the VF(-) and control groups. There was no significant difference in QTp/RR slope among the VF(+), VF(-) and control groups. The Tp-e interval had a negative correlation with the RR interval in the VF(+) group and a positive correlation with the RR interval in the VF(-) and control groups. There was no significant difference in QT/RR, QTp/RR, and Tp-e/RR slopes between BrS patients with SCN5A mutation and those without SCN5A mutation.

CONCLUSIONS

Loss of rate-dependent QT dynamics may be associated with occurrence of VF in BrS.

ADAMTS1 is a unique hypoxic early response gene expressed by endothelial cells

ADAMTS1 (a disintegrin and metalloproteinase with thrombospondin motifs 1) is a member of the matrix metalloproteinase family. We have previously reported that ADAMTS1 was strongly expressed in myocardial infarction. In this study, we investigated whether hypoxia induced ADAMTS1 and investigated its regulatory mechanism. In hypoxia, the expression level of ADAMTS1 mRNA and protein rapidly increased in endothelial cells, but not in other cell types. Interestingly, the induction of ADAMTS1 by hypoxia was transient, whereas vascular endothelial growth factor induction by hypoxia in human umbilical vein endothelial cells (HUVEC) increased in a time-dependent manner. CoCl2, a transition metal that mimics hypoxia, induced ADAMTS1 in HUVEC. The phosphatidylinositol 3-kinase inhibitor LY294002 dose-dependently inhibited the increase of ADAMTS1 mRNA expression in hypoxia. We characterized the promoter region of ADAMTS1, and the secreted luciferase assay system demonstrated that hypoxia induced luciferase secretion in the culture medium 4.6-fold in HUVEC. In the promoter region of ADAMTS1, we found at least three putative hypoxia-inducible factor (HIF) binding sites, and the chromatin immunoprecipitation assay revealed HIF-1 binding to HIF binding sites in the promoter region of ADAMTS1 under hypoxia. Recombinant ADAMTS1 protein promoted the migration of HUVEC under hypoxic conditions. In summary, we found that ADAMTS1 is transiently induced by hypoxia in endothelial cells, and its transcription is mediated by HIF-1 binding. Our data indicate that ADAMTS1 is a novel acute hypoxia-inducible gene.

Coronary artery stenting with high-pressure post-dilation followed by adjunctive thrombolysis after failed coronary angioplasty for acute myocardial infarction: report of three cases

We successfully implanted coronary stents into refractory reoccluded lesions after failed coronary angioplasty in three patients with acute myocardial infarction (AMI). Lesion location was the proximal left anterior descending coronary artery in two patients and the dominant right coronary artery in one patient. The reference diameters of the lesions were 3.64, 3.33, and 3.50 mm, respectively. A stent with a luminal diameter of 3.0 mm was implanted in all patients. Poststenting dilation of the stent was performed at high pressure (18 atm), and urokinase was administered immediately thereafter. Heparin was administered for 24 h with maintenance of activated coagulation time within 180-200 s. Warfarin was then administered to keep the international normalized ratio within 2.5-3.5. Luminal diameters immediately after stenting were 3.14, 2.89, and 3.26 mm, and those at 1 month after stenting were 3.09, 2.81, and 3.12 mm, respectively, indicating good patency. Our experience in these cases suggests that coronary stenting can be applied after unsuccessful coronary angioplasty in selected patients with AMI. The present report includes informative reference data on diameter, postdilation, adjunctive thrombolytic agent administration, and adequate anticoagulation therapy in coronary stenting in this acute application.

Relation of iodine-123 metaiodobenzylguanidine myocardial scintigraphy to endomyocardial biopsy findings in patients with dilated cardiomyopathy

BACKGROUND

Iodine-123 metaiodobenzylguanidine (123I-MIBG) concentrates in adrenergic neurons and has been developed for evaluation of the sympathetic nervous system. Recent studies have demonstrated that the normal heart is clearly visualized by 123I-MIBG cardiac scintigraphy, whereas abnormal 123I-MIBG myocardial uptake and washout have been demonstrated in patients after myocardial infarction and in patients with congestive cardiomyopathy, long QT syndrome, and ventricular tachycardia.

HYPOTHESIS

Based on evidence from recent studies, it can be hypothesized that 123I-MIBG uptake is related to histopathologic changes in the myocardium.

METHODS

The relation of 123I-MIBG uptake to the histologic findings for the heart was studied in 24 patients with dilated cardiomyopathy (DCM). The study group did not include patients with complicating disorders that primarily affect the adrenergic nervous system. The 123I-MIBG uptake was visually assigned one of four grades using the two criteria of the mean score for six regional uptake grades (mean score) and the global score obtained by visual evaluation of the entire image (global score). The 123I-MIBG uptake score was also determined for the region at which the biopsy specimen was obtained (biopsy region score). The histologic findings were evaluated by assigning one of four grades for each of the following five factors: myocyte hypertrophy, myocardial fibrotic change, myocyte degeneration and necrosis, mononuclear cell infiltration, and myocyte disarray. The sum for all grades was defined as the total score, and the global score was also assigned to the overall histologic findings.

RESULTS

All of the global, mean, and biopsy region scores for 123I-MIBG uptake correlated significantly with the global and total scores for the histologic findings. Among the histologic factors, myocyte degeneration showed score correlated with all global, mean, and biopsy region scores for the uptake. Myocyte hypertrophy was associated weakly with the 123I-MIBG uptake scores.

CONCLUSION

These results indicate that 123I-MIBG uptake imaging is associated with histopathologic abnormalities in patients with DCM.

Association of new arterial stiffness parameter, the cardio-ankle vascular index, with left ventricular diastolic function

AIM

Pulse wave velocity has been used as an index of aortic stiffness. Recently, the cardio-ankle vascular index (CAVI), which reflects the stiffness of the aorta independently of blood pressure, has been developed. In this study, we analyzed the relationship between CAVI and left ventricular (LV) diastolic dysfunction.

METHODS

A total of 119 patients were referred for echocardiography to evaluate ventricular function. Patients with reduced systolic function were excluded. Patients were divided on the basis of normal or reduced LV diastolic function determined by echocardiography. CAVI was measured using an automatic waveform analyzer.

RESULTS

CAVI was significantly higher in patients with reduced LV diastolic function than those with normal LV diastolic function (9.0+/-1.1 and 8.5+/-1.1, p=0.009). Multiple linear regression analysis revealed that CAVI was independently associated with the ratio of peak early diastolic velocity to peak atrial diastolic velocity and left atrial diameter. When patients were classified on the basis of CAVI quartiles, multiple logistic regression analysis demonstrated that the highest quartile of CAVI showed an increased odds ratio for the presence of LV diastolic dysfunction.

CONCLUSION

The present study revealed that an increased CAVI was independently associated with LV diastolic dysfunction in patients with preserved systolic function.