A Case of Variant Angina Developing Transient Collateral Circulation During Vasospasm

Variant angina is characterized by spontaneous episodes of angina, usually occurring in the morning and having ST segment elevation on the electrocardiogram. However, in the case presented here, vasospasm and angina was shown by ergonovine without ST elevation. The patient was a 60-year-old man who presented with a 2-year history of frequent chest pain. There were no abnormalities in coronary angiography. When ergonovine (100 µg) was injected, total occlusion of the proximal right coronary artery was seen, without ST elevation at the electrocardiogram. The cause was collateral from left anterior descending artery to distal right coronary artery at the left coronary angiography. Therefore, in a patient with variant angina without ST elevation, a transient collateral circulation during vasospasm should be considered

Sex-related impact on clinical outcomes of patients treated with drug-eluting stents according to clinical presentation: Patient-level pooled analysis from the GRAND-DES registry

Background: The contribution of sex and initial clinical presentation to the long-term outcomes in patients undergoing percutaneous coronary intervention (PCI) is still debated. Methods: Individual patient data from 5 Korean-multicenter drug-eluting stent (DES) registries (The GRAND-DES) were pooled. A total of 17,286 patients completed 3-year follow-up (5216 women and 12,070 men). The median follow-up duration was 1125 days (interquartile range 1097–1140 days), and the primary endpoint was cardiac death at 3 years. Results: The clinical indication for PCI was stable angina pectoris (SAP) in 36.8%, unstable angina pectoris (UAP) or non-ST-segment elevation myocardial infarction (NSTEMI) in 47.4%, and STEMI in 15.8%. In all groups, women were older and had a higher proportion of hypertension and diabetes mellitus compared with men. Women presenting with STEMI were older than women with SAP, with the opposite seen in men. There was no sex difference in cardiac death for SAP or UAP/NSTEMI. In STEMI patients, the incidence of cardiac death (7.9% vs. 4.4%, p = 0.001), all-cause mortality (11.1% vs. 6.9%, p = 0.001), and minor bleeding (2.2% vs. 1.2%, p = 0.043) was significantly higher in women. After multivariable adjustment, cardiac death was lower in women for UAP/NSTEMI (HR 0.69, 95% CI 0.53–0.89, p = 0.005), while it was similar for STEMI (HR 0.97, 95% CI 0.65–1.44, p = 0.884). Conclusions: There was no sex difference in cardiac death after PCI with DES for SAP and UAP/NSTEMI patients. In STEMI patients, women had worse outcomes compared with men; however, after the adjustment of confounders, female sex was not an independent predictor of mortality

A prospective double-blinded randomized study on drug-eluting stent implantation into nitrate-induced maximally dilated vessels in patients with coronary artery disease

Abstract Background Percutaneous coronary intervention (PCI) has been developed using drug-eluting stents (DES); however, stent implantation is associated with concerns of stent thrombosis and target vessel revascularization (TVR). The stent diameter is a critical factor in TVR and clinical events. The nitrate administration in coronary angiography can dilate the reference vessel diameter, enabling accurate vessel size measurement and optimal stent implantation support. This study was designed to evaluate the effect of stent implantation in the maximally dilated coronary artery in patients with coronary artery disease (CAD). Methods This prospective double-blinded randomized (1:1) study is designed to compare the efficacy and safety between DES implantation into the nitrate-induced maximally dilated vessels and conventional DES implantation in patients with CAD. A total of 400 patients who underwent PCI with a sirolimus-eluting stent will be enrolled. The primary endpoint is the mean diameter of the deployed stents. Secondary endpoints include cardiac death, myocardial infarction, stent thrombosis, or ischemia-driven TVR 1 year after the procedure. Discussion This study will be the first randomized controlled trial to evaluate the effect of DES implantation on nitrate-induced maximally dilated vessels in patients with CAD. Trial registration The trial was registered on 18 June 2021 as Effect of Ultimaster Stents Treated to the Most Dilated Coronary Vessels (ClinicalTrials.gov Identifier: NCT04931784)

Colloidal synthesis and thermoelectric properties of La-doped SrTiO3 nanoparticles

We describe n-type nanostructured bulk thermoelectric La-doped SrTiO3 materials produced by spark plasma sintering of chemically synthesized colloidal nanocrystals. The La doping levels could be readily controlled from 3 to 9.0 at% by varying the experimental conditions. We found that nanoscale interfaces were preserved even after the sintering process, and the thermoelectric properties of the nanostructured bulk La-doped SrTiO3 were characterized. An enhanced thermoelectric efficiency was observed and attributed to the large decrease in thermal conductivity obtained with no significant change in the Seebeck coefficient or electrical conductivity. The nanostructured bulk of the La-doped SrTiO3 exhibited a maximum ZT of similar to 0.37 at 973 K at 9.0 at% La doping, which is one of the highest values reported for doped SrTiO3. Furthermore, the materials showed high thermal stability, which is important for practical high-temperature thermoelectric applications. This report demonstrates the high potential for low-cost thermoelectric energy production using highly stable and inexpensive oxide materials.close97

The relationship between J wave and ventricular tachycardia during Takotsubo cardiomyopathy

Abstract Background and objectives Takotsubo cardiomyopathy (TTC) occasionally causes life-threatening ventricular arrhythmia. J wave on surface electrocardiography (sECG) has also been associated with idiopathic ventricular fibrillation and cardiac events; therefore, we investigated whether the presence of J wave on sECG is a potential risk factor for ventricular arrhythmia in patients with TTC. Subjects and methods We performed a retrospective study in 79 patients who were diagnosed with TTC from 2010 to 2014. Among them, 20 (25.3%) were diagnosed with ventricular tachycardia (VT). The J wave on the sECG was defined as J point elevation manifested through QRS notching or slurring at least 1 mm above the baseline in at least two leads. Results A higher prevalence of ventricular tachycardia was observed in patients with J wave. The corrected QT interval (QTc) was significantly longer in the VT group than in the non-VT group. In a multivariate analysis, the presence of J wave appeared to be the only independent predictors of VT [Hazard Ratio (HR) 3.5, p = 0.019]. Conclusion Our results suggest that the presence of J wave on the sECG is significantly associated with VT, and appear to indicate that the presence of J wave is a strong and independent predictor of VT in patients with TTC

Mechanical and Pharmacological Revascularization Strategies for Prevention of Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction: Analysis from Index of Microcirculatory Resistance Registry Data

Objectives. We aimed to identify mechanical and pharmacological revascularization strategies correlated with the index of microcirculatory resistance (IMR) in ST-elevation myocardial infarction (STEMI) patients. Background. Microvascular dysfunction (MVD) after STEMI is correlated with infarct size and poor long-term prognosis, and the IMR is a useful analytical method for the quantitative assessment of MVD. However, therapeutic strategies that can reliably reduce MVD remain uncertain. Methods. Patients with STEMI who underwent primary percutaneous coronary intervention (PCI) were enrolled. The IMR was measured with a pressure sensor/thermistor-tipped guidewire immediately after primary PCI. High IMR was defined as values ≥66th percentile of IMR in enrolled patients (IMR > 30.9 IU). Results. A total of 160 STEMI patients were analyzed (high IMR = 54 patients). Clinical factors for Killip class P=0.006, delayed hospitalization from symptom onset P=0.004, peak troponin-I level P=0.042, and multivessel disease P=0.003 were associated with high IMR. Achieving final thrombolysis in myocardial infarction myocardial perfusion grade 3 tended to be associated with low IMR P=0.119, whereas the presence of distal embolization was significantly associated with high IMR P=0.034. In terms of therapeutic strategies that involved adjusting clinical and angiographic factors associated with IMR, preloading of third-generation P2Y12 inhibitors correlated with reducing IMR value (β = −10.30, P0.05), and postballoon dilatation was associated with high IMR (β = 8.30, P=0.020). Conclusions. In our study, mechanical strategies were suboptimal in achieving myocardial salvage. Preloading of third-generation P2Y12 inhibitors revealed decreased IMR value, indicative of MVD prevention