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Background: It is still unclear whether body mass index (BMI) affects bleeding and cardiovascular events in patients requiring oral anticoagulants (OAC) for atrial fibrillation (AF) and antiplatelet agents after percutaneous coronary intervention (PCI) for coronary artery disease (CAD). The aim of this study was to evaluate the relationship between BMI and clinical events in patients who underwent PCI under OAC therapy for AF., Method: This was a multicenter, observational cohort study conducted at 15 institutions in Japan. AF patients who underwent PCI with drug-eluting stents for CAD were retrospectively and prospectively included. Patients were divided into the Group 1 (BMI <21.3 kg/m2) and the Group 2 (BMI ≥21.3 kg/m2) according to the first-quartile value of BMI. The primary endpoint was net adverse clinical events (NACE), a composite of major adverse cardiovascular events (MACE) and major bleeding events within one year after index PCI procedure., Results: In the 720 patients, 180 patients (25.0%) had BMI value <21.3 kg/m2. While the rates of NACE and MACE were significantly higher in the Group 1 than the counterpart (21.1% vs. 11.9%, p = 0.003 and 17.2% vs. 8.9%, p = 0.004), that of major bleeding did not differ significantly between the 2 groups (5.6% vs. 4.3%, p = 0.54). The cumulative rate of NACE and MACE was significantly higher in the Group 1 than the Group 2 (both log-rank p = 0.002), although that of major bleeding events was equivalent between the 2 groups (log-rank p = 0.41). In multivariable Cox regression analyses, while BMI value <21.3 kg/m2 was not associated with major bleeding events, that cut-off value was an independent predictor for increased NACE and MACE., Conclusions: Among the patients undergoing PCI for CAD and requiring OAC for AF, BMI value was a useful indicator to predict major adverse clinical events., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Yamazaki et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Usefulness of higher (>300 mg) loading doses of clopidogrel has been demonstrated in studies from the United States and Europe. The present study evaluated platelet aggregation after the administration of a 450-mg loading dose of clopidogrel in Japanese patients undergoing coronary stenting. Platelet aggregation was serially measured at baseline, and 2, 4, 6, and 8 h after 450-mg clopidogrel loading in 25 patients undergoing coronary stenting. Platelets were stimulated with 5 and 20 micromol/l adenosine diphosphate (ADP) and aggregation was assessed by optical aggregometry. Platelet aggregation (5 micromol/l ADP 42.8% +/- 13.5% and 20 micromol/l ADP 51.2% +/- 11.6%) was significantly suppressed

In the United States and Europe, patients with coronary stents are maintained on 75 mg clopidogrel. Because the maintenance dose of ticlopidine in patients with coronary stents is 100 mg twice daily in Japan and 250 mg twice daily in the United States and Europe, in Japanese patients a lower dose of clopidogrel may achieve an antiplatelet effect comparable to 200 mg ticlopidine. Platelet aggregation was evaluated in 104 consecutive patients on 50 mg clopidogrel plus aspirin (n = 54) and 200 mg ticlopidine plus aspirin (n = 50). Platelets were stimulated with adenosine diphosphate (5 and 20 mumol/l) and aggregation was assessed by optical aggregometry. There was no significant difference in platelet aggregation induced with 5 (37% +/- 11% vs 38% +/- 15%, not significant) and 20 mumol/l adenosine diphosphate (48% +/- 13% vs 51% +/- 12%, not significant) between 50 mg clopidogrel and 200 mg ticlopidine. In Japanese patients, there is the possibility that a maintenance dose of 50 mg clopidogrel on platelet inhibition is comparable to 200 mg ticlopidine.

Previous intravascular ultrasound (IVUS) studies have shown coronary artery atherosclerosis even in angiographically normal reference segment. However, IVUS has not been performed in all of the three major coronary arteries. A total of 50 patients with single-vessel disease underwent IVUS evaluation in the proximal two-thirds of the three major coronary arteries. Lumen and external elastic membrane cross-sectional areas were measured at 1-mm intervals. To compensate the difference in pullback length among coronary arteries, normalized total plaque and media volume (TPV) was calculated as TPV/number of slices in pullback x median number of slices in study population. Percent plaque and media volume (PPV) was calculated as TPV/Sigma external elastic membrane cross-sectional area x 100. A cross section was defined as atherosclerotic if maximum intimal thickness exceeded 0.5 mm at any point in the vessel circumference. There was no significant difference in normalized TPV, PPV, and the incidence of abnormal intimal thickness between coronary arteries with and without significant stenosis. Frequency distribution of plaque burden was similar. Atherosclerosis is ubiquitous even in coronary arteries without angiographically significant stenosis. The extent of atherosclerosis is similar between coronary arteries with and without significant stenosis.

There is little information about the relationship between balloon inflation time and sirolimus-eluting stent (SES) expansion. In this randomized intravascular ultrasound (IVUS) study, 92 de novo lesions in native coronary arteries that underwent SES implantation were enrolled. Sirolimus-eluting stent was implanted using an inflation pressure of 14 atm. Stent balloon was gradually inflated until 14 atm in 10 s. In the short inflation group, it was deflated immediately after an image of the balloon inflated at 14 atm was taken. Stent balloon inflation lasted 60 s in the long inflation group. Intravascular ultrasound was then performed. The long balloon inflation resulted in a larger stent cross-sectional area (4.9 +/- 1.6 mm(2) vs 4.3 +/- 1.4 mm(2), P < 0.05) and expansion (71% +/- 13% vs 60% +/- 13%, P < 0.001) compared to the short balloon inflation, although stent expansion was relatively low in both groups. The relatively longer balloon inflation time using an inflation pressure of 14 atm results in better SES expansion. However, in the majority of lesions, adequate stent expansion is not achieved even using long balloon inflation, if it is inflated at 14 atm.

Background: The loading dose of ticlopidine is 500 mg in both the US and Europe and 200 mg in Japan. A lower loading dose of clopidogrel might achieve adequate platelet inhibition in Japanese patients., Methods and Results: Platelet aggregation was serially measured at baseline, and 2, 4, 6, and 8 h after 150-mg (n=20) and 300-mg (n=20) clopidogrel loading. Platelets were stimulated with 5 and 20 micromol/L adenosine diphosphate (ADP) and aggregation was assessed by optical aggregometry. Pretreatment ADP-induced platelet aggregation in the 150-mg clopidogrel group did not differ from that of the 300-mg group. The administration of 300-mg clopidogrel loading dose resulted in lower platelet aggregation 2 h after the administration (5 micromol/L ADP: 53+/-9% vs 61+/-12%, p<0.05 and 20 micromol/L ADP: 61+/-10% vs 68+/-9%, p<0.05). A lower platelet aggregation induced with 20 micromol/L ADP was still observed 4 h after the 300-mg clopidogrel loading (58+/-10% vs 65+/-9%, p<0.05)., Conclusions: The 150-mg clopidogrel loading does not achieve rapid platelet inhibition. The 300-mg loading dose should be used to suppress platelet function rapidly even in Japanese patients undergoing coronary stent placement.