Kazuyoshi Hina

Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V1☆

OBJECTIVES We sought to determine the electrocardiographic (ECG) features associated with acute left main coronary artery (LMCA) obstruction. BACKGROUND Prediction of LMCA obstruction is important with regard to selecting the appropriate treatment strategy, because acute LMCA obstruction usually causes severe hemodynamic deterioration, resulting in a less favorable prognosis. METHODS We studied the admission 12-lead ECGs in 16 consecutive patients with acute LMCA obstruction (LMCA group), 46 patients with acute left anterior descending coronary artery (LAD) obstruction (LAD group) and 24 patients with acute right coronary artery (RCA) obstruction (RCA group). RESULTS Lead aVR ST segment elevation (>0.05 mV) occurred with a significantly higher incidence in the LMCA group (88% [14/16]) than in the LAD (43% [20/46]) or RCA (8% [2/24]) groups. Lead aVR ST segment elevation was significantly higher in the LMCA group (0.16 +/- 0.13 mV) than in the LAD group (0.04 +/- 0.10 mV). Lead V(1) ST segment elevation was lower in the LMCA group (0.00 +/- 0.21 mV) than in the LAD group (0.14 +/- 0.11 mV). The finding of lead aVR ST segment elevation greater than or equal to lead V(1) ST segment elevation distinguished the LMCA group from the LAD group, with 81% sensitivity, 80% specificity and 81% accuracy. A ST segment shift in lead aVR and the inferior leads distinguished the LMCA group from the RCA group. In acute LMCA obstruction, death occurred more frequently in patients with higher ST segment elevation in lead aVR than in those with less severe elevation. CONCLUSIONS Lead aVR ST segment elevation with less ST segment elevation in lead V(1) is an important predictor of acute LMCA obstruction. In acute LMCA obstruction, lead aVR ST segment elevation also contributes to predicting a patients clinical outcome.

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 physicians 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.

Serum adipocyte fatty acid-binding protein is independently associated with coronary atherosclerotic burden measured by intravascular ultrasound

OBJECTIVES Adipocyte fatty acid-binding protein (A-FABP) has been shown to have an effect on insulin resistance, lipid metabolism, and atherosclerosis in animals. We therefore investigated the association between the serum A-FABP level and coronary atherosclerosis. METHODS One hundred twenty-five consecutive patients with coronary artery disease (CAD) were enrolled after coronary angiography. Plaque volume in non-culprit coronary arteries was determined using intravascular ultrasound and expressed as percent plaque volume (%PV). Voluntary blood donors (n=120), matched for age and gender, served as controls. Serum levels of A-FABP, adiponectin, and inflammatory markers were measured by enzyme-linked immunosorbent assay. RESULTS The serum A-FABP level in CAD patients was significantly higher than in control subjects (median [25th-75th percentiles], 27.2 [20.5-37.1] ng/mL vs. 18.9 [14.6-24.5] ng/mL) (p<0.01). Serum A-FABP showed 0.74 of the area under the curve in the receiver operating characteristic curve for the detection of CAD, with 76% specificity and 65% sensitivity with a cut-off value of 20.1 ng/mL. Further, in CAD patients, serum A-FABP had a significant correlation with %PV in all subjects (r=0.33, p<0.01). Serum A-FABP was positively correlated with the body mass index, serum interleukin-6 and high-sensitive CRP, and negatively correlated with HDL-cholesterol and serum adiponectin in CAD patients. Stepwise regression analysis revealed that serum A-FABP was independently associated with %PV. CONCLUSION Increased serum A-FABP was significantly associated with a greater coronary plaque burden. Our findings revealed that the measurement of serum A-FABP could be utilized for the evaluation of the extent of coronary atherosclerosis.

Clinical ResearchCoronary Artery DiseaseImpact 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 physicians 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.

Coronary pressure measurement to determine treatment strategy for equivocal left main coronary artery lesions

It is often hard to select a treatment strategy for equivocal left main coronary artery (LMCA) disease. We investigated the usefulness of coronary pressure (CP) measurement for determining the treatment strategy in intermediate LMCA disease. We measured CP in 15 consecutive patients with equivocal LMCA disease (age 67.6 ± 7.5 years, 14 males). Myocardial fractional flow reserve (FFRmyo) was obtained as the ratio of CP distal to the lesion/aortic pressure under maximal coronary dilation. Patients with FFRmyo ≥0.75 and <0.75 received medical therapy and coronary artery bypass grafting (CABG), respectively, and were followed up for 32.5 ± 9.7 (20–47) months. Eight patients received medical therapy and 7 patients underwent CABG in accordance with the FFRmyo criteria noted above. FFRmyo of the LMCA was 0.91 ± 0.01 and 0.61 ± 0.03 in patients who received medical and surgical therapy, respectively. Neither reference vessel diameter, minimal lumen diameter, nor percent diameter stenosis was significantly different between patients who received medical and surgical therapy. During the follow-up period, no patients with medical therapy showed symptoms due to the LMCA lesion. Similarly, 5 of 7 patients with CABG showed improvement of symptoms and the remaining 2 patients were hospitalized with congestive heart failure. No cardiac death was recorded in the patients with medical or surgical therapy. In conclusion, the present results clearly demonstrated that CP is clinically useful for determining the treatment strategy for equivocal LMCA lesions but coronary angiography is not.

Coronary pressure measurement to identify the lesion requiring percutaneous coronary intervention in equivocal tandem lesions.

ObjectivesNo reliable methods are available for determining application of percutaneous coronary intervention for treatment of equivocal tandem lesions. We investigated whether coronary pressure measurement is useful for determining the lesion that requires percutaneous coronary intervention in tandem lesions. MethodsWe measured coronary pressure in 72 consecutive patients with tandem lesions. Myocardial fractional flow reserve (FFRmyo) was obtained as the ratio of coronary pressure distal to the lesion/aortic pressure under maximal hyperemia. If the FFRmyo across the tandem lesions was ≥0.75, we deferred percutaneous coronary intervention for the lesion. When the tandem lesions showed FFRmyo<0.75, percutaneous coronary intervention was performed on the lesion that showed angiographically higher stenosis. When FFRmyo was <0.75 after one-lesion percutaneous coronary intervention, this intervention was carried out on the remaining lesion. ResultsWe deferred percutaneous coronary intervention for 26 patients (36.1%), and performed percutaneous coronary intervention in 46 patients (63.8%). We performed percutaneous coronary intervention for one lesion in 19 patients (26.4%) and for both lesions in 27 patients (37.5%). Among patients in whom percutaneous coronary intervention was deferred, only two patients (7.7%) required target lesion revascularization during the follow-up period. This rate was not higher than that in the 46 patients who underwent percutaneous coronary intervention for one or two lesions (six patients, 13.0%). Similarly, the target lesion revascularization in lesions with initially deferred percutaneous coronary intervention (5.6%, 4/71 lesions) was not higher than that in lesions with percutaneous coronary intervention (15.1%, 11/73 lesions). Major cardiac events, cardiac death and acute myocardial infarction, did not occur in patients with deferred percutaneous coronary intervention and in those with percutaneous coronary intervention during the follow-up period. ConclusionOur results clearly showed that coronary pressure measurement was clinically useful for identifying equivocal tandem lesions requiring percutaneous coronary intervention.

Q-Wave Regression Unrelated to Patency of Infarct-Related Artery or Left Ventricular Ejection Fraction or Volume after Anterior Wall Acute Myocardial Infarction Treated With or Without Reperfusion Therapy

We examined the relation of Q-wave regression to left ventricular (LV) indexes in acute anterior wall myocardial infarction (AMI) in relation to reperfusion therapy. A total of 94 patients with their first anterior wall AMI (segment 6 or 7 occlusion according to the American Heart Association classification) were examined. The follow-up period with 12-lead electrocardiograms ranged from 6 to 60 months (mean 24 +/- 18). An abnormal Q wave was defined as > 40 ms and > 25% of the R-wave amplitude. Q-wave regression was defined as Q-wave disappearance and r-wave regression > 0.1 mV in > or = 1 lead. Contingency tables with the chi-square test and analysis of variance were used for assessment of the relation between Q-wave regression and angiographic and clinical indexes. Q-wave regression in > or = 1 lead was found in 77% of the patients. The incidence of Q-wave regression in patients with patent infarct-related artery (81%) was not significantly different from that in those with an occluded lesion (67%). Q-wave regression appeared within 1 month in 60% of patients with a patent infarct-related artery but in 25% of those with an occluded lesion. No difference in the incidence of Q-wave regression was seen between patients with lesions at segments 6 (81%) and 7 (70%), or between those with (75%) and without (77%) collateral circulation. Q-wave regression did not correlate with LV ejection fraction, LV end-diastolic or end-systolic volumes, or regional wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of corrected QT dispersion with symptoms improvement in patients receiving cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is theoretically expected to affect repolarization as well as depolarization. We studied the effects of CRT on corrected QT (QTc) dispersion in association with symptomatic improvement. QTc dispersion was analyzed in 26 consecutive patients (67 ± 6 years old, 18 men and 8 women) who underwent CRT. CRT responders and nonresponders were defined as patients showing and not showing ≥1 class New York Heart Association symptomatic improvement 3 months after CRT, respectively. QTc interval, QRS width, and QTc dispersion were measured automatically from digital data using an analyzing system. There were 18 CRT responders and 8 nonresponders among the patients. CRT responders showed significantly larger QTc dispersion than CRT nonresponders before CRT (102 ± 26 vs 40 ± 12 ms, P < 0.01). A significant decrease in QTc dispersion by CRT was observed in responders (102 ± 26 to 52 ± 15 ms, P < 0.01). In contrast, QTc dispersion was not decreased by CRT in nonresponders (40 ± 12 to 39 ± 11 ms, not significant). The difference observed before CRT was thus abolished after CRT (52 ± 15 vs 39 ± 11 ms, not significant). Baseline values and changes in QRS width or QTc, as well as asynchrony of wall motion determined by tissue Doppler imaging, were not different between CRT responders and nonresponders before CRT. The present study with a small number of patients shows the potential utility of QTc dispersion for distinguishing CRT responders from CRT nonresponders before CRT, and warrants further study with a greater number of patients.

Autoregulation by the right coronary artery in dogs with open chests; comparison with the left coronary artery

Experiments were conducted to study autoregulatory responses of the right and left coronary arteries in dogs with open chests. The right and left circumflex coronary artery were cannulated and perfused with blood from the femoral artery via a pressurized reservoir. The perfusion pressure was varied in steps over a wide range and coronary blood flow rates were measured. Both the right and left coronary arteries exhibited autoregulation but the pressure at the lower end of the autoregulatory range was lower in the right (39.8±9.1 mm Hg) than in the left circumflex coronary artery (57.6±14.5 mm Hg). The slope of the pressure-flow relationship in the autoregulatory range was less steep in the right than the left circumflex coronary artery. The closed-loop gain when the perfusion pressure was less than 100 mm Hg was greater in the right than in the left circumflex coronary artery. Increases in the right ventricular afterload produced by pulmonary artery constriction decreased the closed-loop gain, shifted the autoregulatory range upward and to the right, and made the slope steeper. These results indicate that more effective autoregulation is carried out by the right than the left circumflex coronary artery.

Safety and Efficacy of Under-dosing Non-vitamin K Antagonist Oral Anticoagulants in Patients Undergoing Catheter Ablation for Atrial Fibrillation.

Background: Some patients with atrial fibrillation (AF) received underdoses of non-vitamin K antagonist oral anticoagulants (NOACs) in the real world. Underdosing is defined as administration of a dose lower than the manufacturer recommended dose. Objectives: To identify the efficacy and safety of underdosing NOACs as perioperative anticoagulation for atrial fibrillation ablation. Methods: We retrospectively analyzed patients who received rivaroxaban or dabigatran etexilate according to dosage: adjusted low dosage (reduced by disturbed renal function; n = 30), underdosage (n = 307), or standard dosage (n = 683). Non-vitamin K antagonist oral anticoagulants and dosing decisions were at the discretion of treating cardiologists. Results: Patients who received underdosed NOACs were older, more often female, and had lower body weight and lower renal function than those who received standard dosages. Activated clotting time at baseline in patients who received adjusted low dosage or underdosages was slightly longer than that in patients receiving standard dosages (156 ± 23, 151 ± 224, and 147 ± 24 seconds, respectively). Meaningful differences were not observed in other coagulation parameters. Adjusted low-, under-, and standard-dosing regimens did not differ in perioperative thromboembolic complications (0/30, 0.0%; 1/307, 0.3%; and 0/683, 0%, respectively) or major (0/30, 0.0%; 2/307, 0.6%; 3/683, 0.4%) and minor (1/30, 3.3%; 13/307, 4.2%; 25/683, 3.6%) bleeding episodes. When comparisons were performed for each NOAC, similar results were observed. Conclusions: With consideration of patient condition, age, sex, body weight, body mass index, and renal function, underdosing NOACs was effective and safe as a perioperative anticoagulation therapy for atrial fibrillation ablation. The therapeutic range of NOACs is potentially wider than manufacturer recommendations.BACKGROUND Some patients with atrial fibrillation (AF) received under-doses of non-vitamin K antagonist oral anticoagulants (NOACs) in the real world. Under-dosing is defined as administration of a dose lower than the manufacturer recommended dose. OBJECTIVES To identify the efficacy and safety of under-dosing NOACs as perioperative anticoagulation for AF ablation. METHODS We retrospectively analyzed patients who received rivaroxaban or dabigatran etexilate according to dosage: adjusted low-dosage (reduced by disturbed renal function; n = 30), under-dosage (n = 307), or standard-dosage (n = 683). NOACs and dosing decisions were at the discretion of treating cardiologists. RESULTS Patients who received under-dosed NOACs were older, more often female, and had lower body weight, and lower renal function than those who received standard-dosages. Activated clotting time at baseline in patients who received adjusted low- or under-dosages was slightly longer than that in patients receiving standard-dosages (156 ± 23, 151 ± 224, and 147 ± 24 seconds, respectively). Meaningful differences were not observed in other coagulation parameters. Adjusted low-, under-, and standard-dosing regimens did not differ in perioperative thromboembolic complications (0/30, 0.0%; 1/307, 0.3%; and 0/683, 0%, respectively), or major (0/30, 0.0%; 2/307, 0.6%; 3/683, 0.4%) and minor (1/30, 3.3%; 13/307, 4.2%; 25/683, 3.6%) bleeding episodes. When comparisons were performed for each NOAC, similar results were observed. CONCLUSION With consideration of patient condition, age, sex, body weight, body mass index, and renal function, under-dosing NOACs was effective and safe as a perioperative anticoagulation therapy for AF ablation. The therapeutic range of NOACs is potentially wider than manufacturer recommendations.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND) , where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.