Comparison of Discriminative Ability of Bleeding Risk Criteria and Scores for Predicting Short- and Mid-Term Major Bleeding Events in Patients Undergoing Percutaneous Coronary Intervention

Background: This study aimed to compare the discriminative ability of the Japanese Version of High Bleeding Risk (J-HBR), Academic Research Consortium for High Bleeding Risk (ARC-HBR), and Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy (PRECISE-DAPT) scores for predicting major bleeding events. Methods and Results: Between January 2017 and December 2020, 646 consecutive patients who underwent successful percutaneous coronary intervention (PCI) were enrolled. We scored the ARC-HBR and J-HBR criteria by assigning 1 point to each major criterion and 0.5 point to each minor criterion. The primary outcome was major bleeding events, defined as Bleeding Academic Research Consortium type 3 or 5 bleeding events. According to the J-HBR, ARC-HBR, and PRECISE-DAPT scores, 428 (66.3%), 319 (49.4%), and 282 (43.7%) patients respectively had a high bleeding risk. During the follow-up period (median, 974 days), 44 patients experienced major bleeding events. The area under the curve (AUC) using the time-dependent receiver operating characteristic curve for major bleeding events was 0.84, 0.82, and 0.83 within 30 days and 0.86, 0.83, and 0.80 within 2 years for the J-HBR, ARC-HBR, and PRECISE-DAPT scores, respectively. The AUC values did not differ significantly among the 3 bleeding risk scores. Conclusions: The J-HBR score had a discriminative ability similar to the ARC-HBR and PRECISE-DAPT scores for predicting short- and mid-term major bleeding events.

Successful Removal of an Entrapped Stent Delivery Catheter Using Two Arterial Sheaths in the Ipsilateral Groin

Entrapment of devices, such as a Rota bar, an extension catheter, or an intravascular ultrasound device, during percutaneous coronary intervention has been reported and bailout strategies have been discussed. However, there have been few reports on entrapment of devices during endovascular treatment (EVT). A 70-year-old man was referred to our clinic for the management of rest pain in his left lower limb. His left ankle-brachial index was unmeasurable and computed tomography angiography revealed total occlusion of the left common, external iliac, and superficial femoral arteries (SFA). He was diagnosed as having symptomatic limb-threatening ischemia and EVT was planned. The first EVT was performed on an occluding lesion in the left iliac artery. We used a transradial approach and deployed two bare nitinol stents in the left iliac artery without complications. One week after the first EVT, the second EVT was performed on an occluding lesion in the left SFA. A 6.0-French (Fr) guide sheath was inserted antegradely through the left common femoral artery. The occluded lesion was dilated with a 4.0 mm plain balloon, following which intravascular ultrasound revealed a localized severe stenotic lesion in the distal part of the SFA. A 6.0 mm drug-eluting stent was deployed to cover the stenotic lesion in the distal part of the SFA without pre-dilation; however, the stenotic lesion did not dilate sufficiently. When we attempted to extract the stent delivery catheter, we could not detach its tip from the localized severe stenotic lesion and were unable to remove it by force or external compression. Therefore, we decided to implement a double guide technique by inserting a 4.0-Fr sheath simultaneously into the left common femoral artery adjacent to the first puncture site together with another 0.014-inch guidewire via a 4.0-Fr sheath to get past the lesion in which the catheter tip was embedded. We then used a 3.0-mm plain balloon to dilate the severe stenotic lesion sufficiently to enable the removal of the stent delivery catheter. Another 6.0-mm drug-eluting stent was then deployed, after the first stent, to cover the occluded lesion in the middle part of the SFA. Hemostasis was safely achieved at both puncture sites by manual compression. A double guide technique, as in percutaneous coronary intervention, is useful for the bailout of an entrapped device during EVT. Careful consideration of the access site and size and length of the second guide sheath are necessary.

Association of preoperative clinical frailty and clinical outcomes in elderly patients with stable coronary artery disease after percutaneous coronary intervention

There are few reports on the long-term clinical outcome after percutaneous coronary intervention (PCI) in patients with stable coronary artery disease (CAD) complicated with frailty. This novel study investigated the association between pre-PCI frailty and long-term clinical outcomes in elderly patients aged 65 years or older with stable CAD who underwent elective PCI. We assessed 239 consecutive patients aged 65 years or older with stable CAD who underwent successful elective PCI at Kagoshima City Hospital between January 1st, 2017 and December 31st, 2020. Frailty was retrospectively assessed using the Canadian Study and Aging Clinical Frailty Scale (CFS). Based on the pre-PCI CFS, patients were divided into two groups: the non-frail (CFS < 5) and the frail (CFS ≥ 5) group. We investigated the association between pre-PCI CFS and major adverse cardiovascular events (MACEs) defined as the composite of all-cause death, non-fatal myocardial infarction, non-fatal stroke, and heart failure requiring hospitalization. Additionally, we assessed the association between pre-PCI CFS and major bleeding events defined as Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding. The mean age was 74.8 ± 7.0 years, and 73.6% were men. According to the pre-PCI frailty assessment, 38 (15.9%) and 201 (84.1%) were classified as frail and non-frail groups, respectively. During a median follow-up of 962 (607-1284) days, 46 patients developed MACEs and 10 patients developed major bleeding events. Kaplan-Meier curves showed a significantly higher incidence of MACE in the frail group compared to those in the non-frail group (Log-rank p < 0.001). Even in multivariate analysis, pre-PCI frailty (CFS ≥ 5) was independently associated with MACE (HR 4.27, 95% CI 1.86-9.80, p-value: < 0.001). Additionally, the cumulative incidence of major bleeding events was significantly higher in the frail group than in the non-frail group (Log-rank p = 0.001). Pre-PCI frailty was an independent risk factor for MACE and bleeding events in elderly patients with stable CAD who underwent elective PCI.

Prognostic predictors in patients with cardiopulmonary arrest: A novel equation for evaluating the 30-day mortality

BACKGROUND

Early prediction of outcomes after cardiopulmonary arrest (CPA) is important for considering the best support. Our purpose was to evaluate predictors of the 30-day mortality in patients with CPA after return of spontaneous circulation (ROSC) and to assess an equation for calculating the 30-day mortality using clinical parameters.

METHODS

We retrospectively analyzed the data of 194 consecutive patients with CPA and ROSC in a derivation study (2015-2022). We compared clinical parameters between the survived (n = 78) and dead (n = 116) patients. We derived an equation for estimated probability of death based on clinical parameters, using multivariate logistic regression analysis. The reliability of the equation was validated in 80 additional patients with CPA.

RESULTS

The 30-day mortality was associated with sex, witnessed cardiac arrest, bystander cardiopulmonary resuscitation (CPR), CPA due to acute myocardial infarction, pupil diameter, Glasgow Coma Scale score (GCS), presence of light reflex, arterial or venous pH, lactate levels, initial ventricular fibrillation (VF), CPA time, and age. The derived logistic regression equation was as follows: Estimated probability of death = 1 / (1 + e-x), x = (0.25 × bystander CPR) + (0.44 × pupil diameter) - (0.14 × GCS) + (0.09 × lactate) - (1.87 × initial VF) + (0.07 × CPA time) + (0.05 × age) - 7.03. The cut-off value for estimated probability of death calculated by this equation was 54.5 %, yielding a sensitivity, specificity, and accuracy of 86.2 %, 80.8 %, and 84.5 %, respectively. In the validation model, these values were 81.8 %, 85.7 %, and 82.5 %, respectively.

CONCLUSIONS

The 30-day mortality may be calculated after ROSC in patients with CPA using simple clinical parameters. This equation may facilitate further best support for patients with CPA.

Successful Endovascular Therapy Using the Transtibial Approach in a Patient With a History of Iliofemoral and Femorofemoral Surgical Bypass

Multiple stenotic lesions may restrict the access sites for endovascular therapy in the lower extremity arteries. Because guide sheaths used for endovascular therapy have recently become easier to insert, they are directly inserted into the posterior tibial or dorsalis pedis artery to perform the transtibial approach. We herein describe an 81-year-old man who was admitted to our hospital because of claudication of the left lower extremity. He had a history of left iliofemoral and femorofemoral bypass surgery. The patient's symptom was due to a stenotic lesion extending from the left common femoral artery to the distal part of the left superficial femoral artery. In an angiographic procedure using the antegrade approach via the right radial artery, a multipurpose catheter became stuck in the middle of the left iliofemoral bypass. The antegrade ipsilateral approach was too close to the stenotic lesion for the insertion of the guide sheath. Therefore, a retrograde approach using a 5-French guide sheath inserted via the dorsalis pedis artery was successfully performed.

Cardio-Ankle Vascular Index and Left Atrial Reverse Remodeling After Ablation for Atrial Fibrillation

Arterial stiffness has been reported to cause left atrial (LA) remodeling due to increased left ventricular filling pressure, resulting in atrial fibrillation (AF). This study aimed to evaluate the association between LA reverse remodeling (LARR) after AF ablation and cardio-ankle vascular index (CAVI), an indicator of arterial stiffness.This study included 333 patients with AF (171 with paroxysmal AF and 162 with nonparoxysmal AF) and LA enlargement (LA volume index ≥ 34 mL/m²) who underwent AF ablation between December 2008 and July 2021. CAVI was evaluated preoperatively during AF (n = 155, 46.5%) or sinus rhythm (n = 178, 53.5%). Participants were divided into groups with LARR (n = 133, 39.9%) and without LARR (n = 200, 60.1%) according to whether the degree of decrease in LA volume index on transthoracic echocardiography 6 months after ablation was ≥ 15% or < 15%, respectively.Sinus rhythm was maintained in 168 (50.5%) patients within 3-6 months after the index procedure. Univariate analysis revealed that preoperative CAVI (7.80 ± 1.22 versus 8.57 ± 1.09, P < 0.001) was significantly lower, and the maintenance of sinus rhythm (61.6% versus 43.0%, P = 0.0011) was higher in the group with LARR. Multivariate logistic regression analysis revealed that preoperative CAVI was independently associated with LARR (odds ratio, 0.60, 95% confidence interval, 0.46-0.78, P < 0.001).In patients with AF and LA enlargement, CAVI is independently associated with LA reverse remodeling after catheter ablation.

Adventitial Cystic Disease in the Popliteal Artery Diagnosed by Intravascular Ultrasound Imaging

The prevalence of peripheral artery disease (PAD) has been increasing in parallel with the increasing prevalence of the atherosclerotic disease. Therefore, we have to be familiar with the diagnostic approach used for ischemic symptoms in the lower limbs. Adventitial cystic disease (ACD) is rare but not negligible as one of the differential diagnoses of intermittent claudication (IC). Although duplex ultrasound and magnetic resonance imaging (MRI) are helpful tools for the diagnosis of ACD, further imaging modality is needed to avoid misdiagnosis. A 64-year-old man with a mitral valve prosthesis presented to our hospital with a one-month history of IC in the right calf after walking for approximately 50 meters. On physical examination, the pulse in the right popliteal artery was not palpable, nor were the dorsal pedis artery and posterior tibial artery, although there were no other symptoms of ischemia. His right ankle-brachial index (ABI) was 1.12 at rest but decreased to 0.50 after exercise. Three-dimensional computed tomography (CT) angiography revealed a severe stenotic lesion approximately 70 mm long in the right popliteal artery. Therefore, we diagnosed PAD in the right lower limb and planned endovascular therapy. The stenotic lesion was markedly reduced on catheter angiography when compared with CT angiography. However, intravascular ultrasound (IVUS) detected little atherosclerosis and cystic lesions within the wall in the right popliteal artery that did not involve the arterial lumen. Especially, IVUS clearly demonstrated that the crescent-shaped cyst compressed the arterial lumen eccentrically and other cysts surrounded the lumen circumferentially like petals. Because IVUS revealed these cysts to be extravascular structures, the patient was subsequently thought to have ACD of the right popliteal artery. Fortunately, his cysts reduced in size spontaneously and his symptoms disappeared. We have monitored the patient's symptoms, ABI, and findings on duplex ultrasound for seven years, during which there has been no recurrence. In this case, we diagnosed ACD in the popliteal artery by IVUS rather than duplex ultrasound and MRI.

Clinical Features of the Aslanger Pattern to Compensate for the Limitation of ST-Elevation Myocardial Infarction (STEMI) Criteria

BACKGROUND

ST-elevation is one of the most valuable electrocardiogram findings to diagnose acute myocardial infarction. However, more than a quarter of acute coronary occlusions are missed by this criterion, causing a delay in revascularization. Therefore, there should be awareness of the limitations of the current criteria and new electrocardiographic findings are required as a diagnostic tool to compensate for them. The Aslanger pattern is a specific electrocardiographic finding in acute inferior myocardial infarction with multivessel disease and allows the detection of inferior myocardial infarction that does not show ST-elevation, leading to rapid revascularization. However, in patients with the Aslanger pattern, the hemodynamic characteristics, such as the rate of shock and the use of mechanical circulatory support, as well as prognostic characteristics such as the in-hospital mortality rate, have not yet been clarified.

METHODS

In this study, we retrospectively surveyed the current practice on the basis of ST-elevation myocardial infarction (STEMI) criteria in patients with acute coronary artery occlusion presenting with inferior myocardial infarction. We examined the clinical characteristics of the Aslanger pattern.

RESULTS

Based on the STEMI criteria, 71.8% (51/72) of patients were diagnosed with STEMI from an acute electrocardiogram, and 28.2% (21/78) were diagnosed with non-STEMI. As expected, ruling out in all acute coronary artery occlusions using STEMI criteria alone was difficult. A total of 48% of patients with non-STEMI had the Aslanger pattern. In addition, 80% of patients with the Aslanger pattern had multivessel disease, 30% had the use of the mechanical circulatory support, and 20% had in-hospital mortality.

CONCLUSION

This study suggests that the Aslanger pattern is useful not only for diagnosis, but also for predicting hemodynamic collapse and a poor prognosis. Therefore, we should share information on Aslanger pattern with other physicians and use this pattern in daily practice.

Development of a risk prediction score for hypertension incidence using Japanese health checkup data

Hypertension is a risk factor for cardiovascular disease. We developed a simple scoring method for predicting future hypertension using health checkup data. A total of 41,902 participants aged 30-69 years without baseline hypertension who underwent annual health checkups (mean age, 52.3 ± 10.2 years; male, 47.7%) were included. They were randomly assigned to derivation (n = 27,935) and validation cohorts (n = 13,967) at a ratio of 2:1. In the derivation cohort, we performed multivariable logistic regression analysis and assigned scores to each factor significantly associated with 5-year hypertension. We evaluated the predictive ability of the scores using area under the curve (AUC) analysis and then applied them to the validation cohort to assess their validity. The score including items requiring blood sampling ranged from 0 to 14 and included seven indicators (age, body mass index, blood pressure, current smoking, family history of hypertension, diabetes, and hyperuricemia). The score not including items requiring blood sampling ranged from 0 to 12 and included five indicators (the above indicators, except diabetes and hyperuricemia). The score not including items requiring blood sampling was better; blood sampling did not improve diagnostic ability. The AUC of the score not including items requiring blood sampling was 0.76, with a sensitivity and specificity of 0.82 and 0.60, respectively, for scores ≥6 points. The incidence of hypertension gradually and constantly increased (from 0.9 to 49.6%) as the score increased from 0 to ≥10. Analysis in the validation cohort yielded similar results. We developed a simple and useful clinical prediction model to predict the 5-year incidence of hypertension among a general Japanese population. The model had reasonably high predictive ability and reproducibility.

Percutaneous Extraction for Misplacement of Pacemaker Leads Within the Coronary Artery and Left Ventricle

A 75-year-old man, who underwent inadvertent misplacement of pacemaker leads into the left coronary artery and left ventricle through the subclavian artery, was referred to our hospital. We safely performed percutaneous lead extraction in collaboration with surgeons and with the patient under general anesthesia. (Level of Difficulty: Advanced.).

Decrease in red cell distribution width as a useful predictor of success after catheter ablation for atrial fibrillation: a retrospective multi-center study

Red cell distribution width (RDW) is reportedly associated with cardiovascular events, including atrial fibrillation (AF). We investigated whether the RDW values were associated with the outcomes of catheter ablation for AF. This retrospective multicenter study included 501 patients with AF (239 paroxysmal AF cases, 196 persistent AF cases, and 66 long-standing persistent AF cases) who underwent initial AF ablation between March 2017 and May 2018. The RDW values were evaluated before and at 1-3 months after the procedure. The patients were stratified based on the recurrence of AF within 1 year after the index procedure with a blanking period of 3 months into recurrence group (107 patients, 21.4%) and no-recurrence group (394 patients, 78.6%). There were no significant differences in preoperative RDW values between the groups (p = 0.37). The RDW value did not change significantly after the ablation in the recurrence group (13.55-13.60%, p = 0.37), although it decreased significantly in the no-recurrence group (13.64-13.37%, p < 0.001). Multivariate Cox proportional hazards regression analyses revealed that a postoperative change in RDW (ΔRDW) was independently associated with AF recurrence (hazard ratio 2.00, 95% confidence interval 1.42-2.76, p < 0.001). Receiver operating characteristic curve analysis revealed that a ΔRDW cut-off value of - 0.1% provided a c-statistic of 0.65 for predicting AF recurrence. Decrease in RDW during the blanking period after ablation independently predicted the 1-year success of AF ablation.

Dynamics of Soluble Thrombomodulin and Circulating miRNAs in Patients with Atrial Fibrillation Undergoing Radiofrequency Catheter Ablation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world and has a high risk of thromboembolism. The most effective approach, catheter ablation, requires evaluation by electrocardiography. The aim of our study was to investigate novel clinical markers that predict restoration of sinus rhythm (SR) after catheter ablation. Seventy-eight consecutive patients with AF underwent catheter ablation and were separated into 2 groups: restored SR and recurrent AF. The levels of 4 blood proteins (serum or plasma) and 3 mature microRNAs (miRNAs) and their primary miRNAs (pri-miRNAs) in serum were measured before and after ablation, and the associations between each parameter were analyzed statistically. Soluble thrombomodulin (s-TM) and plasminogen activator inhibitor-1 (PAI-1) levels increased above baseline after ablation in both the restored SR (s-TM 11.55 [2.92] vs 13.75 [3.38], P < .001; PAI-1 25.74 [15.25] vs 37.79 [19.56], P < .001) and recurrent AF (s-TM 10.28 [2.78] vs 11.67 [3.37], P < .001; PAI-1 26.16 [15.70] vs 40.74 [22.55], P < .001) groups. Levels of C-reactive protein and asymmetric dimethylarginine were not significantly changed. Pri-miR-126 levels significantly decreased after ablation in the recurrent AF group, but the other miRNAs and pri-miRNAs did not. The measurement of s-TM and pri-miR-126 in blood was a useful tool to reflect the condition of AF patients with catheter ablation.

The implantation of a loop recorder to detect the cause of pre-syncope in an 85-year-old man

The patient was an-85-year-old man with hypertension and hyperlipidemia. The patient had a history of faintness on standing. He visited our hospital after experiencing chest oppression and pre-syncope in 2015. Brain magnetic resonance imaging and echocardiography did not detect any structural brain or heart disease. Ischemic heart disease was suspected based on the myocardial scintigraphy findings, but coronary angiography revealed no unusual findings. Holter electrocardiography did not reveal the reason for his symptoms. Because he had experienced 2-second sinus arrest rather than faintness or pre-syncope during the Holter monitoring (not an indication for the implantation of a pacemaker), we implanted a loop recorder to detect the cause of pre-syncope.The loop recorder required that he or his family to manually send the telemetry monitoring data, but he and his wife did not understand how to do it. After the loop recorder failed to reveal the cause of his symptoms, he was hospitalized for its extraction. When we manually checked the loop recorder data on the day of hospitalization, sinus arrest of >3 seconds was detected 271 times; the maximum sinus arrest was 4 seconds. Sinus arrest was confirmed to be cause of his symptoms. His symptoms completely disappeared after the implantation of a permanent pacemaker.Although faintness is not rare in elderly people, it can be difficult to diagnose. An implantable loop recorder was useful for diagnosing pre-syncope; however, in the present case, it was difficult for the elderly patient and his wife to perform telemetry monitoring.

The optimal setting of complex fractionated atrial electrogram software in substrate ablation for atrial fibrillation

BACKGROUND

Complex fractionated atrial electrogram (CFAE)-targeted catheter ablation (CFAE ablation) requires a high rate of atrial fibrillation (AF) termination to provide good outcomes. We determined the optimal settings of CFAE software.

METHODS

In our 430 consecutive patients, AF was terminated in 97 (234/242) and 79% (149/188) of patients with paroxysmal and persistent AF, respectively, by CFAE ablation combined with (31%) or without (69%) pulmonary vein isolation, occasionally with nifekalant infusion. We analyzed 109 consecutive patients who underwent CFAE ablation to determine the optimal settings for comparing subjective versus objective decisions by the CFAE software on CARTO3. We compared three settings: the default setting (0.05-0.15 mV, 50-120 ms) and two modified settings (#1: 0.05-0.30 mV, 40-70 ms, #2: 0.05-0.13 mV, 10-20 ms). We retrospectively analyzed 11,425 points during left atrial mapping before ablation and 10,306 points that were subjectively detected and ablated as CFAE points. An interval confidence level ≥6 denoted a site with CFAE.

RESULTS

With the default setting, the accuracy, sensitivity, specificity, positive productive value, and negative productive values were 67, 42, 77, 48, and 73%, respectively. With modified setting #1, the values were 78, 55, 87, 74, and 77%, respectively, versus 64, 82, 60, 53, and 91%, respectively, for modified setting #2.

CONCLUSION

These data suggest that setting #1 was generally superior to the default setting, whereas setting #2 was optimal for excluding areas not requiring ablation. The optimal CFAE software setting was a voltage of 0.05-0.30 mV and an interval parameter of 40-70 ms.

Characterization of the effect of serum bilirubin concentrations on coronary endothelial function via measurement of high-sensitivity C-reactive protein and high-density lipoprotein cholesterol

Bilirubin can prevent oxidation of low-density lipoprotein (LDL) and may protect against atherosclerosis and coronary heart disease (CHD). The goal of this study was to characterize the relationship between bilirubin and CHD through measurements of bilirubin concentration, coronary endothelial function, and markers of oxidative stress, inflammation, and lipid/glucose metabolism. The study population consisted of 141 patients without CHD who underwent Doppler flow study. Vascular reactivity was examined by intracoronary administration of papaverine, acetylcholine (ACh) and nitroglycerin using a Doppler guide wire. Serum bilirubin, high-sensitivity C-reactive protein (hsCRP), malondialdehyde-modified LDL, LDL cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting plasma glucose (FPG), and immunoreactive insulin were also measured. Homeostasis model assessment insulin resistance index and estimated glomerular filtration rate (eGFR) were calculated. Univariate analysis revealed that both percent change in coronary blood flow (CBF) and coronary artery diameter induced by ACh correlated positively with log-transformed bilirubin (r = 0.22, P < 0.05; r = 0.20, P < 0.05, respectively). Percent change in CBF in response to ACh correlated positively with eGFR (r = 0.24, P < 0.05) and correlated inversely with age, LDL-C, and log-transformed FPG (r = -0.24, P < 0.05; r = -0.17, P < 0.05, r = -0.22, P < 0.05, respectively). Multivariate analysis revealed that log-transformed bilirubin was the only independent predictor of percent change in CBF in response to ACh. Multivariate analysis revealed that log-transformed hsCRP and HDL-C were independent predictors of log-transformed bilirubin. These results suggest that a high level of bilirubin is associated with favorable coronary endothelial function, which may be mediated via the effect of bilirubin on inflammation and HDL-C.

Relationship between bilirubin concentration, coronary endothelial function, and inflammatory stress in overweight patients

AIM

Bilirubin has antioxidant properties and may protect against atherosclerosis and coronary heart disease (CHD). Further, in patients with metabolic syndrome, hyperbilirubinemia is associated with attenuation of insulin resistance. The aim of the present study was to determine the relationship between serum bilirubin concentration and coronary endothelial function in overweight patients.

METHODS

The study population consisted of 107 patients without CHD who underwent coronary flow studies. Vascular reactivity was examined by intra-coronary administration of papaverine and nitroglycerin. Coronary endothelial function was evaluated by assessing the change in coronary artery diameter to papaverine [percent change in flow-mediated dilatation (%FMD)] and nitroglycerin (%NTG). Serum total bilirubin, high-sensitivity C-reactive protein (hs-CRP), high density lipoprotein-cholesterol (HDL-C), fasting plasma glucose and immunoreactive insulin levels were also measured, and the homeostasis model assessment insulin resistance (HOMA-IR) index was calculated. Patients were divided into two groups according to body mass index (BMI): an overweight group (BMI ≥ 25; n = 36) and a normal weight group (BMI < 25; n = 71).

RESULTS

In the overweight group, univariate analysis revealed that log-transformed total bilirubin was positively correlated with %FMD and HDL-C (r = 0.38, p< 0.05; r = 0.30, p < 0.05, respectively) and was inversely correlated with log-transformed hs-CRP and HOMA-IR (r = -0.45, p < 0.01; r = -0.45, p< 0.05, respectively). Multivariate analysis revealed that log-transformed hs-CRP was the only independent predictor of log-transformed total bilirubin (p< 0.05).

CONCLUSIONS

These results suggest that a high bilirubin level was associated with favorable coronary endothelial function in overweight patients. Further, the anti-inflammatory effects of bilirubin may mediate this effect.

Usefulness of the adenosine triphosphate with a sufficient observation period for detecting reconduction after pulmonary vein isolation

BACKGROUND

Although reconduction after pulmonary vein (PV) isolation is considered to play a key role in the recurrence of paroxysmal atrial fibrillation (AF), there have been few reports regarding the precise time course of early reconduction. Several studies have suggested that transient PV reconduction facilitated by adenosine may predict long-term AF recurrence. This study was designed to clarify the incidence and time course of early reconduction after PVI during the procedure and to confirm whether the use of ATP after a certain observation period was useful to detect early reconduction after PVI.

METHODS

In 21 patients (18 males, 56 +/- 11 years) with drug refractory AF, radiofrequency circumferential PV antrum ablation was performed in all 4 PVs. After the completion of isolation, electrograms in each PV were repeatedly recorded (1.98 +/- 0.57 times per PV) using a circular mapping catheter for an observation period of 87 +/- 29 minutes. After isolation of all 4 PVs, 30 mg of adenosine triphosphate (ATP) was administered during isoproterenol infusion.

RESULTS

PV electrical isolation was initially achieved in all 81 PVs. During the observation period, 12 (15%) PVs in 10 (48%) of 21 patients exhibited spontaneous reconduction. Among the remaining 69 PVs, 8 (12%) additional PVs had reconduction with the use of ATP. All PV reconduction was successfully eliminated by 4.5 +/- 2.2 additional radiofrequency applications.

CONCLUSION

A sufficient observation period and the use of ATP are useful to detect early reconduction after PV isolation.

Relationship between hyperglycemia and coronary vascular resistance in non-diabetic patients

BACKGROUND

Hyperglycemia upon hospital admission in patients with acute myocardial infarction is associated with the no-reflow phenomenon after successful reperfusion, and increased mortality. However, the mechanism underlying this phenomenon remains unclear. Therefore, the aim of this study was to characterize coronary hemodynamics in a homogenous group of non-diabetic patients without coronary artery disease.

METHODS AND RESULTS

A total of 104 consecutive non-diabetic patients (mean age, 62+/-14 years) without coronary artery disease underwent Doppler flow study of the left anterior descending coronary artery. Vascular reactivity was examined by intra-coronary administration of papaverine, acetylcholine (Ach), and nitroglycerin using a Doppler guidewire. Coronary vascular resistance (CVR) was calculated as the mean arterial pressure divided by coronary blood flow (CBF). Baseline CVR was shown as CVR at control and minimal CVR was shown as CVR with papaverine administration. Fasting plasma glucose (FPG) level had a significant, positive correlation with baseline CVR and minimal CVR (r=0.24, p<0.02 and r=0.21, p<0.05, respectively). Hemoglobin A1c (HbA1c) also had a significant, positive correlation with baseline CVR and minimal CVR (r=0.31, p<0.01 and r=0.32, p<0.01, respectively). The percent change in CBF induced by Ach was inversely correlated with HbA1c but not with FPG (r=0.22, p<0.05 and r=0.06, p=0.57, respectively). By contrast, neither FPG nor HbA1c had significant correlation with coronary flow reserve to papaverine.

CONCLUSION

These data demonstrate that elevated glucose levels are associated with increases in baseline and minimal coronary vascular resistance. These changes may contribute to unfavorable coronary hemodynamics in non-diabetic patients without coronary heart disease.

Toll-like receptor 2 expression level on monocytes in patients with viral infections: monitoring infection severity

For viral infectious diseases, reliable biomarkers capable of monitoring recovery and therapeutic effects and that simultaneously discriminate between viral and bacterial infection are necessary. In this study, by using flow-cytometric quantification system, Toll-like receptor 2 (TLR2) expression levels on monocytes of influenza patients (n=47) were compared with those of healthy volunteers (n=50). Subsequently, throughout their acute, convalescent and healed phases, TLR2, C-reactive protein (CRP), serum amyroid A (SAA), and neopterin levels were followed. Additionally, TLR2 levels in other viral infectious diseases were assayed. The results showed that TLR2 level in influenza patients was remarkably up-regulated in acute phase compared to healthy volunteers (p<0.001). Thereafter, TLR2 levels normalized in good accordance with their recovery processes. CRP and neopterin levels were relatively widely distributed from normal to abnormally high levels in acute phase in spite of similar disease severity among the patients. SAA levels did not necessarily reflect the patients' clinical course during their recovery. Clinical observations of other viral infections also indicated that TLR2 levels were compatible with infection severity. TLR2 expression level on monocytes might serve as a unique biomarker useful in viral infectious diseases.

A technique for diagnosis of accessory pathway using the H-H and A-A intervals of the first entrained cycle during ventricular overdrive pacing

Although advancement of succeeding atrial activation by a ventricular extrastimulus (VES) on His refractoriness during supraventricular tachycardia (SVT) has been used as evidence of an accessory pathway (AP), the sensitivity of this method is suboptimal. This study was designed to compare the His-His (H-H) and atrial-atrial (A-A) intervals of the first entrained cycle during ventricular overdrive pacing (VOD) for the diagnosis of AP, in comparison to the conventional VES method. In 55 patients with SVT, a VES was elicited on His refractoriness during SVT. VOD was subsequently performed at cycle lengths 30 to 40 ms shorter than SVT cycle lengths. When the A-A interval became equal to the pacing cycle length after some beats of VOD, the cycle was considered the first entrained cycle and the H-H interval preceding the A-A interval was measured. VES advanced the next atrial activation in 16 patients (52%) with an AP, but in no patient without an AP. The H-H interval of the first entrained cycle was longer than the pacing cycle length by > or =15 ms in all patients with an AP, but was equal to the pacing cycle length in all patients without an AP. The criterion of H-H greater than A-A by > or =15 ms for the first entrained cycle provided higher diagnostic yield for AP compared with the VES method(100% vs 52%, p <0.001). In conclusion, this new criterion reliably diagnoses the presence of an AP in patients with SVT, with higher sensitivity compared with the VES method.

Mortality and Stroke Reduction After Successful Catheter Ablation for High-risk Patients with Atrial Fibrillation

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Pulmonary Mycobacterium avium complex infection associated with the IVS8-T5 allele of the CFTR gene

BACKGROUND

The T5 allele in intron 8 (IVS8) on specific haplotype backgrounds (e.g., long TG repeats) causes abnormal splicing in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, and is also known to be associated with chronic airway diseases.

OBJECTIVE

To investigate the role of CFTR variations for susceptibility to pulmonary Mycobacterium avium complex (MAC) infection.

PARTICIPANTS

Three hundred patients with pulmonary MAC infection (72 males, 228 females; mean age at onset 61.6 + or - 12.4 years) took part in this study. Diagnosis of MAC infection was based on American Thoracic Society criteria. Clinical profiles were collected and blood samples were genotyped for TG repeats, poly-T and M470V polymorphisms.

RESULTS

We found significantly higher T5 frequency in MAC patients than in healthy controls from our own study (0.035 and 0.005, respectively, P = 0.023) and other reports. Homozygote for the T5 allele was found in two MAC patients. All T5 alleles were associated with longer TG repeats, the TG12 or TG13 allele. Seventeen of the 21 T5 alleles appeared to be associated with the V470 allele. Other polymorphisms did not show any significant differences in frequency.

CONCLUSIONS

These findings suggest that the IVS8 5T allele might be involved in susceptibility to pulmonary MAC infection.

Time-course of Toll-like receptor 2 expression, as a predictor of recurrence in patients with bacterial infectious diseases

The clinical course of bacterial infectious diseases is often variable, especially in elderly patients. Thus, new biological markers have been sought to predict the disease outcome. Recent studies have revealed that Toll-like receptor (TLR) 2 and/or TLR4 on circulating monocytes are significantly up-regulated in bacterial infections. However, the lack of reliable quantification methods hampers extensive study on the modulation of these molecules in response to the patient's clinical condition. In this study, we developed a new quantitative flow cytometric analysis system for TLR2. We then carried out a longitudinal study on TLR2 expression levels on monocytes from patients suffering from bacterial infectious diseases during and after antibiotic treatment. The clinical outcome divided 37 patients into 'cure' (n = 24) and 'recurrence' (n = 13) groups. A significant difference between the two groups was recognized in the TLR2 levels just after antibiotic treatment (antibody-binding sites/cell, 4395 +/- 784 versus 5794 +/- 1484, P < 0.001). The risk of recurrence was associated significantly with TLR2 (P < 0.001), but not C-reactive protein (P = 0.351) levels assayed during the first remission. Furthermore, antibiotic effectiveness was associated inversely with TLR2 levels during antibiotic administration (P < 0.001). Taken together, TLR2 expression levels on monocytes provide critical information for planning treatment against bacterial infectious diseases.

Adiponectin is a better predictor of endothelial function of the coronary artery than HOMA-R, body mass index, immunoreactive insulin, or triglycerides

BACKGROUND

Previous studies have demonstrated that decreased levels of circulating adiponectin correlate with endothelial dysfunction in peripheral arteries. However, the relationship between adiponectin levels and endothelial function in coronary arteries remains unclear. The goal of the present study was to determine whether circulating adiponectin concentrations are a useful predictor of coronary endothelial function.

METHODS

Thirty-six consecutive non-diabetic patients with normal or mildly diseased coronary arteries were enrolled in this study. Coronary endothelial function was evaluated by coronary vascular response to acetylcholine (Ach). The relationship between coronary vasoreactivity and adiponectin or other biochemical or anthropometric parameters was investigated. The predictive value of adiponectin level for assessment of coronary endothelial dysfunction was assessed at the best cut-off point.

RESULTS

In a simple regression analysis, log-transformed adiponectin concentrations positively correlated with the percent change in coronary blood flow (CBF) and coronary artery diameter (CAD) induced by Ach (r=0.62, p<0.0001; r=0.63, p<0.0001, respectively). Insulin resistance index (HOMA-R), body mass index, immunoreactive insulin, and triglycerides concentrations also significantly correlated with the percent change in CBF and CAD. However, in a multiple regression analysis, log-transformed adiponectin concentration was the only independent predictor of the percent change in CBF and CAD (p<0.0001; p<0.0001, respectively). Furthermore, patients with adiponectin concentrations <6.3 mg/L demonstrated coronary endothelial dysfunction with high specificity both in terms of CBF and CAD response (85%; 88%, respectively).

CONCLUSIONS

Adiponectin is a better predictor of coronary endothelial function than other factors such as HOMA-R, body mass index, immunoreactive insulin, and triglycerides.

Effect of Right Ventricular Apex Pacing on the Tei Index and Brain Natriuretic Peptide in Patients with a Dual-Chamber Pacemaker

BACKGROUND

Asynchronous electrical activation induced by right ventricular apex (RVA) pacing can cause various abnormalities in left ventricular (LV) function, particularly in the context of severe LV dysfunction or structural heart disease. However, the effect of RVA pacing in patients with normal LV and right ventricular (RV) function has not been fully elucidated. The aim of this study was to characterize the effects of RVA pacing on LV and RV function by assessing isovolumic contraction time and isovolumic relaxation time divided by ejection time (Tei index) and by assessing changes in plasma brain natriuretic peptide (BNP).

METHODS

Doppler echocardiographic study and BNP measurements were performed at follow-up (mean intervals from pacemaker implantation, 44+/-75 months) in 76 patients with dual chamber pacemakers (sick sinus syndrome, n=30; atrioventricular block, n=46) without structural heart disease. Patients were classified based on frequency of RVA pacing, as determined by 24-hour ambulatory electrocardiogram (ECG) that was recorded just before echocardiographic study: pacing group, n=46 patients with RVA pacing>or=50% of the time, percentage of ventricular paced 100+/-2%; sensing group, n=30, patients with RVA pacing<50% of the time, percentage of ventricular paced 3+/-6%.

RESULTS

There was no significant difference in mean heart rate derived from 24-hour ambulatory ECG recordings when comparing the two groups (66+/-11 bpm vs 69+/-8 bpm). LV Tei index was significantly higher in pacing group than in sensing group (0.67+/-0.17 vs 0.45+/-0.09, P<0.0001), and the RV Tei index was significantly higher in pacing group than in sensing group (0.34+/-0.19 vs 0.25+/-0.09, P=0.011). Furthermore, BNP levels were significantly higher in pacing group than in sensing group (40+/-47 pg/mL vs 18+/-11 pg/mL, P=0.017). With the exception of LV diastolic dimension (49+/-5 mm vs 45+/-5 mm, P=0.012), there were no significant differences in other echocardiographic parameters, including left atrium (LA) diameter (35+/-8 mm vs 34+/-5 mm), LA volume (51+/-27 cm3 vs 40+/-21 cm3), LV systolic dimension (30+/-6 mm vs 29+/-7 mm), or ejection fraction (66+/-9% vs 63+/-11%), when comparing the two groups.

CONCLUSIONS

These findings suggest that the increase of LV and RV Tei index, LVDd, and BNP are highly correlated with the frequency of the RVA pacing in patients with dual chamber pacemakers.

Regulation of K(ATP) channels by P(2Y) purinoceptors coupled to PIP(2) metabolism in guinea pig ventricular cells

We used patch-clamp techniques to elucidate the regulatory mechanisms of ATP-sensitive K(+) (K(ATP)) channels by stimulation of P(2) purinoceptors in guinea pig ventricular myocytes. Extracellular ATP at 0.1 mM transiently inhibited by 90.5 +/- 5.0% the whole cell K(ATP) channel current evoked by a reduction in intracellular ATP concentration to 0.5 mM and exposure to 30 microM pinacidil. ADP and AMP (both 1 mM) also decreased the current by 42.8 +/- 9.3% and 9.4 +/- 4.8%, respectively, but adenosine did not, even at 10 mM. ATP-induced channel inhibition was hardly observed in the presence of 0.2 mM suramin, 0.2 mM guanosine 5'-O-(2-thiodiphosphate), or 0.1 mM compound 48/80, whereas it was not influenced by the presence of 0.1 microM staurosporine or 10 mM 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid in the pipette. In the presence of 10 microM wortmannin or the absence of ATP in the cytosol, the ATP-induced channel inhibition was irreversible. Phosphatidylinositol 4,5-bisphosphate (PIP(2)) at 0.1 mM in the outside-out patch pipette prevented ATP-induced channel inhibition. The half-maximal internal ATP concentrations for inhibition of channel activity determined in inside-out membrane patches were 13.8 microM in the presence and 1.12 mM in the absence of 0.1 mM ATP at the external side. It is concluded that activity of K(ATP) channels is modulated by extracellular ATP by a mechanism involving P(2Y) purinoceptors coupled to GTP-binding proteins associated with reduction of the sarcolemmal PIP(2) concentration via stimulation of phospholipase C.

[Serological diagnosis of pulmonary tuberculosis and nontuberculous pulmonary mycobacteriosis]

OBJECTIVE

The present study was undertaken to evaluate the utility of the serodiagnosis of pulmonary tuberculosis and nontuberculous pulmonary mycobacteriosis by ELISA using a Pathozyme-Myco kit (Myco kit) and a Pathozyme-TB complex kit (TB kit) (OMEGA Diagnostics Ltd.).

STUDY POPULATION

The subjects comprised 256 healthy volunteers (HV, healthy hospital employees), 66 patients with sputum-positive active pulmonary tuberculosis (apTB), 14 patients with healed pulmonary tuberculosis (hpTB), 24 patients with nontuberculous pulmonary mycobacteriosis (NTM) and 32 patients with pulmonary diseases other than mycobacteriosis.

RESULTS

1) The serum IgG antibody titers determined with the Myco kit were significantly higher in the apTB group (p < 0.01), the hpTB group (p < 0.01), and the NTM group (p < 0.01) than those in the HV and the other pulmonary disease group. At a cut-off value of the mean + 2SD of the values obtained in the HV, the positive rate was 47.0% in patients with apTB, 50.0% in those with NTM, 21.4% in those with hpTB, 3.1% in those with other pulmonary diseases, and 1.6% in the HV. Analysis of ROC curves showed that the HV and the pulmonary mycobacteriosis group (apTB and NTM) were best distinguished by a cut-off value of -0.280 OD (log), with the sensitivity and the specificity being 83.3% and 78.5%, respectively. It was impossible to distinguish apTB from NTM. 2) The serum IgG antibody titers determined with the TB kit were significantly higher in the apTB group than those in the HV (p < 0.01), the NTM group (p < 0.05) and the other pulmonary disease group (p < 0.01). No significant difference was observed between the HV and the patients with NTM or those with other pulmonary diseases. Although the positive rate of the test was low in the apTB group (42.4%), there was a significant difference between apTB and NTM (12.5%) (p < 0.05), suggesting that apTB could be distinguished from NTM. 3) Since the serum antibody titers determined by the Myco kit showed no significant difference between apTB and NTM, and there was also no difference in the positivity between the two diseases, we performed serologic examination using the Myco kit to detect both diseases as pulmonary mycobacteriosis. After diagnosing pulmonary mycobacteriosis by the Myco kit, we then used the TB kit to separate apTB from NTM. In this case, the sensitivity and specificity of the test were 55.6% and 85.7%, respectively. Better methods should be developed to distinguish apTB from nontuberculous mycobacteriosis.

State-dependent modification of ATP-sensitive K+ channels by phosphatidylinositol 4,5-bisphosphate

With inside-out patch recordings in ventricular myocytes from the hearts of guinea pigs, we studied ATP-sensitive K+ (K(ATP)) channels activated by phosphatidylinositol 4,5-bisphosphate (PIP2) with respect to sensitivity to ATP when in either a rundown state (RS) or a non-rundown state (NRS). Rundown of K(ATP) channels was induced by exposure either to ATP-free solution or to ATP-free solution containing 19 microM Ca2+. Exposure of membrane patches to 10 microM PIP2 reactivated channels with both types of rundown. The reactivation by PIP2 did not require ATP in the bath. The IC50 of channels recovered from RS and before the rundown was 37.1 and 31.1 microM, respectively. PIP2 irreversibly increased the mean current when the channel was in the NRS. This was associated with a shift of IC50 to 250.6 microM after PIP2 exposure. PIP2 activates NRS K(ATP) channels by decreasing their sensitivity to ATP, whereas PIP2 reactivates RS-K(ATP) channels independently of ATP without changing ATP sensitivity.

On the mechanism of ADP-induced alteration of sulphonylurea sensitivity in cardiac ATP-sensitive K(+) channels

1. To study the mechanism of regulation of sulphonylurea sensitivity in ATP-sensitive K(+) (K(ATP)) channels, we used the inside-out patch clamp technique in guinea-pig ventricular myocytes. 2. In the absence of nucleotides, the half maximal concentration of tolbutamide inhibition of K(ATP) channels (IC(50)) was 0.4 mM, and it decreased to 0.1 mM when 0.1 mM ATP was added. 3. Increasing the ADP concentration from 0 to 0.1 and 0.3 mM in the absence of ATP shifted the IC(50) from 0.4 to 5.3 and 11.4 mM, respectively. Increasing the ADP concentration further to 1 and 3 mM conversely reduced the IC(50) to 9.5 and 4.4 mM, respectively. 4. In the absence of Mg(2+) and ADP, the IC(50) was calculated to 16.6 mM which was found to be less, 12.3, 5.1 and 2.5 mM, respectively, when the ADP concentration was increased to 0.1, 0.3 and 1 mM. 5. The IC(50)s for tolbutamide obtained at various concentrations of ADP in the presence of Mg(2+) were best fitted by equations reflecting a model that assumed two binding sites for ADP; one is a high affinity site that reduces the sensitivity to the sulphonylurea, while the other is a low affinity site that increases such sensitivity. Dissociation constants calculated for ADP to sites 1 and 2 were 2.6 microM and 46.7 mM, respectively. In the absence of Mg(2+), data were fitted by equations corresponding to a single site model (site 2); the dissociation constant for ADP was 25.0 mM. 6. It is concluded that ADP modifies tolbutamide sensitivity by binding to two sites. The high affinity site is strongly Mg(2+)-dependent, whereas the low affinity site is Mg(2+)-independent.

[Significance of serum surfactant protein-D (SP-D) level in patients with pulmonary tuberculosis]

Elevated levels of serum surfactant protein-D (SP-D) have been previously reported in patients with idiopathic pulmonary fibrosis (IPF) and pulmonary alveolar proteinosis. To determine whether the same change is seen in other pulmonary diseases, especially pulmonary tuberculosis (TB), we measured the serum SP-D levels in active pulmonary TB (smear and/or culture: positive), acute interstitial pneumonia (AIP), IPF, acute exacerbation of IPF, hypersensitivity pneumonitis (HP), pneumoconiosis, bronchiectasis, and bacterial pneumonia by an enzyme-linked immunosorbent assay using monoclonal antibodies to human lung SP-D, and compared them with those of healthy elderly subjects over 50 years of age. The SP-D level in the healthy elderly subjects was 57.6 +/- 38.4 ng/ml (mean +/- SD, n = 287). The levels in patients with active pulmonary TB (140.6 +/- 18.2 ng/ml, n = 49), AIP (1,021 ng/ml, n = 1), IPF (307.0 +/- 180.7 ng/ml, n = 42), acute exacerbation of IPF (817.7 +/- 283.6 ng/ml, n = 3), and HP (716.6 +/- 548.8 ng/ml, n = 4) were significantly higher than those in the healthy elderly controls (p < 0.05), whereas those of pneumoconiosis, bronchiectasis, and bacterial pneumonia, 121.9 +/- 92.8 ng/ml (n = 8), 93.9 +/- 72.9 ng/ml (n = 11), and 72.7 +/- 3.4 ng/ml (n = 4), respectively, showed no significant difference with the controls. In active pulmonary TB, the percentage of patients whose serum SP-D levels were over 134.6 ng/ml (mean + 2SD of healthy elderly controls) was 34.7%, and therefore we considered the serum SP-D level was not useful for the diagnosis of pulmonary TB. However, it was significantly higher in the patients with cavity formation than in those without (p < 0.05), and there was a significant positive correlation between the serum SP-D level and the number of tubercle bacilli in the sputum (r = 0.416, p = 0.00165), erythrocyte sedimentation rate at 1 hr (r = 0.489, p < 0.01), and CRP level (r = 0.383, p = 0.003). These findings suggest that the serum SP-D level is a useful indicator of the disease activity in pulmonary TB.

[Suspected leiomyosarcoma of the trachea]

A 73-year-old women was admitted to our hospital because of dyspnea, bloody sputum, and an apparent intratracheal tumor. A chest X-ray film from August 1991 showed a sharply circumscribed soft-tissue density in the trachea at the level of the aortic arch. By March 1993 the tumor had grown from 15 mm to 20 mm in diameter. A chest CT scan and fiberoptic bronchoscopy showed an intratracheal tumor that occupied 80% to 90% of the tracheal lumen. The tumor was resected on March 26, 1993. Histopathological study revealed a suspected leiomyosarcoma of the trachea. Only 18 cases of leiomyosarcoma of the trachea have previously been reported worldwide. We know of only 3 previous reports of the case of suspected leiomyosarcoma of the trachea in Japan.