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.

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.

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.

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.

Analysis and measurement of dielectrophoretic manipulation of particles and lymphocytes using rail-type electrodes

A particle manipulation and sorting device using the dielectrophoretic (DEP) force is described in this study. The device consists of "ladder-type", "flip-type" and "oblique rail-type" electrode regions. The ladder-type and rail-type electrodes can generate a DEP force distribution that captures the particles, the DEP force of which is negative, in the area located at the center of the electrodes. The ladder-type electrode can align the particles with equal spacing in the streamwise direction. Using the flip-type electrode, which pushes the particles away, in combination with these electrodes, the direction of the particle and timing can be selected with high accuracy, reliability, and response. In the first half of this study, a numerical simulation is carried out to calculate the particle motion and evaluate the performance of the ladder-type electrode. Several models are used to investigate the influences of the non-uniformity of the electric field and the electric interaction of the surface charges and polarizations. Experiments are then carried out to demonstrate the motions of the particles and the sorting reliability. The trajectories and the probability density functions of the particles at the inlet and outlet of the electrode region showed that by using these electrodes the particles can be aligned, sorted, and guided accurately.

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.

Aging curve of neuromotor function by pronation and supination of forearms using three-dimensional wireless acceleration and angular velocity sensors

We have developed an evaluation system for pronation and supination of forearms. The motion of pronation and supination of the forearm is used as a diagnosis method of developmental disability, etc. However, this diagnosis method has a demerit in which diagnosis results between doctors are not consistent. It is hoped that a more quantitative and simple evaluation method is established. Moreover it is hoped a diagnostic criteria obtained from healthy subjects can be established to diagnose developmental disorder patients. We developed a simple and portable evaluation system for pronation and supination of forearms. Three-dimensional wireless acceleration and angular velocity sensors are used for this system. In this study, pronation and supination of forearms of 570 subjects (subjects aged 6-12, 21-100) were examined. We could obtain aging curves in the neuromotor function of pronation and supination. These aging curves obtained by our developed system, has the potential to become diagnostic criteria for a developmental disability, etc.

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.

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.

Association between Toll-like receptors and the extent and severity of coronary artery disease in patients with stable angina

OBJECTIVES

Toll-like receptors mediate the innate immune response triggered by pathogen-associated molecular patterns, and atherosclerosis can be considered a state of chronic inflammation whereby immune system cells accumulate within the intima of the arterial wall. The goal of this study was to determine the relation of Toll-like receptors to the extent and severity of coronary artery disease.

METHODS

Angiographic vessel score and Gensini score were used to evaluate the extent and severity of coronary atherosclerosis. Sixty-two consecutive patients with stable angina were grouped as follows: those with insignificant (<50%) coronary stenosis (group 1), and those with 1 (group 2), 2 (group 3), or 3-vessel disease (group 4). The expression of Toll-like receptor 1, 2, and 4 on circulating CD14+ monocytes was analyzed by flow-cytometry in all patients.

RESULTS

Toll-like receptor 2 had a positive correlation with the vessel score and Gensini score (r=0.46, P<0.001; r=0.32, P<0.02, respectively). Toll-like receptor 4 also positively correlated with the vessel score and Gensini score (r=0.47, P<0.001; r=0.29, P<0.05, respectively). No significant correlation existed between the expression of Toll-like receptor 1 and the vessel score or Gensini score. Further, there was no significant correlation between high-sensitivity C-reactive protein and the vessel score or Gensini score.

CONCLUSION

These data suggest that Toll-like receptor 2 and 4 expression correlates with the extent and severity of coronary artery disease.

Cibenzoline attenuates coronary systolic reversal flow in a patient with hypertrophic obstructive cardiomyopathy: a case report

Effects of cibenzoline on coronary hemodynamics, especially systolic reversal flow, were assessed in a 53-year-old man with hypertrophic obstructive cardiomyopathy by coronary flow study using a Doppler guidewire. Intravenous administration of cibenzoline resulted in decreases in the pressure gradient (60 to 0mmHg) and systolic left ventricular pressure (162 to 126 mmHg), and an increase in systolic arterial pressure (102 to 132mmHg). Furthermore, the systolic reversal flow observed at baseline was markedly diminished following administration of cibenzoline. Therefore, we speculate that cibenzoline reduces ventricular wall stress by diminishing the left ventricular obstruction that occurs with compression of the intramyocardial arteries. Cibenzoline-induced attenuation of coronary systolic reversal flow may be associated with the effectiveness of cibenzoline for diminishing the left ventricular obstruction.

Elevated levels of brain natriuretic peptide as a predictor of impaired coronary endothelial function in patients with left ventricular remodeling

BACKGROUND

Plasma levels of brain natriuretic peptide (BNP) correlate with left ventricular remodeling, but the relationship between BNP induction and coronary function remains unclear.

OBJECTIVES

The present study assessed BNP production in response to left ventricular enlargement and investigated the relationship between BNP production and coronary vasodilating function in patients with left ventricular remodeling.

METHODS

Patients (n = 63) with normal or mildly diseased coronary arteries underwent Doppler flow study of the left anterior descending coronary artery. Vascular reactivity was examined using intracoronary acetylcholine, papaverine and nitroglycerin using a Doppler guidewire.

RESULTS

Left ventricular end-diastolic dimension was positively correlated with BNP (r = 0.45, p < 0.001) in all patients. BNP was significantly and inversely correlated with percentage change in coronary artery diameter induced by acetylcholine (r = -0.56, p < 0.001) but not by nitroglycerin (r = -0.20, p = 0.28) in patients with left ventricular end-diastolic dimension > or = 55 mm (n = 32). By contrast, BNP was not significantly correlated with percentage change in coronary artery diameter induced by either acetylcholine or nitroglycerin in patients with left ventricular end-diastolic dimension < 55 mm (n = 31). Further, BNP was not correlated with the percentage change in coronary blood flow induced by acetylcholine or by papaverine in patients with or without left ventricular remodeling.

CONCLUSIONS

The elevation in plasma BNP levels that occurs in association with left ventricular enlargement is a predictor of impaired endothelium-dependent vasodilation in conductance coronary arteries.

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.

Association of coronary shear stress with endothelial function and vascular remodeling in patients with normal or mildly diseased coronary arteries

BACKGROUND

The relationship between coronary remodeling, shear stress and endothelial function remains unclear.

OBJECTIVE

The present study investigated the effects of mechanical factors on structure and function of epicardial coronary arteries.

METHODS

Patients (group 1: %area stenosis<40%, n=55; or group 2: %area stenosis>or=40%, n=17) with a discrete mildly stenotic lesion (%diameter stenosis<30%) underwent intravascular ultrasound examination of the left anterior descending coronary artery for determination of vessel area, lumen area, plaque area, cross-sectional areas at reference segments, and remodeling index (the ratio of vessel area at the culprit lesion to vessel area at the proximal reference site). Further, vascular reactivity was examined using intracoronary administration of acetylcholine, papaverine, and nitroglycerin.

RESULTS

Vessel area significantly correlated with plaque area in both groups (r=0.65, P<0.0001 and r=0.85, P<0.0001). Group 1 showed significantly greater acetylcholine-induced percentage changes in coronary blood flow (67+/-70 vs. 16+/-75%, P<0.05) and coronary artery diameter (-7+/-18 vs.-32+/-31%, P<0.01) and also significantly smaller coronary wall shear stress (65+/-27 vs. 81+/-32 dynes/cm, P<0.05) than group 2. The percentage increase in coronary blood flow induced by acetylcholine was significantly and positively correlated with remodeling index in group 1 (r=0.64, P<0.0001) but not in group 2 (r=-0.03, P=0.90) and was also significantly and positively correlated with coronary wall shear stress in group 1 (r=0.46, P<0.001) but not in group 2 (r=-0.33, P=0.19).

CONCLUSIONS

Endothelium-dependent vasodilation in the resistance coronary artery correlates with remodeling via increased wall shear stress when target lesions %area stenosis is <40%.

Contribution of increased minimal coronary resistance and attenuated vascular adaptive remodeling to myocardial ischemia in patients with systemic hypertension and ventricular hypertrophy

This study assessed the impact of coronary vascular adaptive remodeling and coronary vascular reactivity on myocardial ischemia in patients with hypertension and left ventricular hypertrophy. Myocardial ischemia is associated with impaired endothelium-independent vasodilation of resistance coronary arteries and increased minimal coronary resistance. These changes may occur in association with lumen reduction caused by attenuated adaptive remodeling in response to plaque accumulation.

Control of catecholamine release and blood pressure with octreotide in a patient with pheochromocytoma: a case report with in vitro studies

A 65-year-old male patient with pheochromocytoma, whose hypertensive episodes were uncontrolled using conventional therapy, was successfully treated with octreotide (SMS 201-995). The serum catecholamine level and the urinary excretion of catecholamines decreased after 300 microgram/day of octreotide was administered. To clarify the mechanisms of octreotide that lower catecholamine released from a tumor, we studied the in vitro effects of octreotide on membrane potentials and voltage-dependent Ca(2+) channel (VDCC) current using the whole-cell patch-clamp technique in single pheochromocytoma cells dispersed after tumor resection. The action potentials were reversibly inhibited with 10 microM octreotide. In addition, the VDCC current evoked by depolarized pulses from the holding potential of -60 mV was inhibited with 10 microM octreotide. Octreotide is useful for controlling blood pressure before surgery in some patients with uncontrolled hypertension caused by a pheochromocytoma.