Fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation (FLASH): Study protocol for a randomized controlled noninferiority trial.

BACKGROUND: Artificial intelligence-based quantitative coronary angiography (AI-QCA) has been developed to provide a more objective and reproducible data about the severity of coronary artery stenosis and the dimensions of the vessel for intervention in real-time, overcoming the limitations of significant inter- and intraobserver variability, and time-consuming nature of on-site QCA, without requiring extra time and effort. Compared with the subjective nature of visually estimated conventional CAG guidance, AI-QCA guidance provides a more practical and standardized angiography-based approach. Although the advantage of intravascular imaging-guided PCI is increasingly recognized, their broader adoption is limited by clinical and economic barriers in many catheterization laboratories. METHODS: The FLASH (fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation) trial is a randomized, investigator-initiated, multicenter, open-label, noninferiority trial comparing the AI-QCA-assisted PCI strategy with optical coherence tomography-guided PCI strategy in patients with significant coronary artery disease. All operators will utilize a novel, standardized AI-QCA software and PCI protocol in the AI-QCA-assisted group. A total of 400 patients will be randomized to either group at a 1:1 ratio. The primary endpoint is the minimal stent area (mm2), determined by the final OCT run after completion of PCI. Clinical follow-up and cost-effectiveness evaluations are planned at 1 month and 6 months for all patients enrolled in the study. RESULTS: Enrollment of a total of 400 patients from the 13 participating centers in South Korea will be completed in February 2024. Follow-up of the last enrolled patients will be completed in August 2024, and primary results will be available by late 2024. CONCLUSION: The FLASH is the first clinical trial to evaluate the feasibility of AI-QCA-assisted PCI, and will provide the clinical evidence on AI-QCA assistance in the field of coronary intervention. CLINICAL TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT05388357.

Impact of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction and Chronic Kidney Disease.

BACKGROUND: In the setting of acute myocardial infarction (AMI), there are no data regarding the benefits of intravascular ultrasound (IVUS) for chronic kidney disease (CKD) patients.Methods and Results: This study used data from the Korea Acute Myocardial Infarction Registry, a large, multicenter prospective cohort. We evaluated 1,759 patients with AMI and CKD, defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2, and patients were classified into 2 groups: with and without IVUS. The primary outcome was target lesion failure (TLF) at 3 years. The hazard ratio (HR) of TLF according to eGFR was also analyzed. A total of 1,759 patients with AMI and CKD who underwent IVUS-guided PCI (19.2%) had a significantly lower risk of TLF at 3 years (8.9% vs. 15.3%; HR 0.55; 95% confidence interval [CI]: 0.38 to 0.81; P=0.002) than those who underwent angiography-guided PCI, regardless of their eGFR and the presence of end-stage renal disease (ESRD). The results were consistent after confounder adjustment and inversed probability weighting. CONCLUSIONS: In patients with CKD and AMI who underwent PCI with 2nd-generation DES implantation, the use of IVUS guidance was associated with a significant reduction in 3-year TLF and showed consistently favorable outcomes regardless of eGFR and ESRD.

Comparison of alternate preparative techniques on wall thickness in coronary artery bypass grafts: The HArVeST randomized controlled trial.

BACKGROUND: The success of coronary artery bypass grafting surgery (CABG) is dependent on long-term graft patency, which is negatively related to early wall thickening. Avoiding high-pressure distension testing for leaks and preserving the surrounding pedicle of fat and adventitia during vein harvesting may reduce wall thickening. METHODS: A single-centre, factorial randomized controlled trial was carried out to compare the impact of testing for leaks under high versus low pressure and harvesting the vein with versus without the pedicle in patients undergoing CABG. The primary outcomes were graft wall thickness, as indicator of medial-intimal hyperplasia, and lumen diameter assessed using intravascular ultrasound after 12 months. RESULTS: Ninety-six eligible participants were recruited. With conventional harvest, low-pressure testing tended to yield a thinner vessel wall compared with high-pressure (mean difference [MD; low minus high] -0.059 mm, 95% confidence interval (CI) -0.12, +0.0039, p = .066). With high pressure testing, veins harvested with the pedicle fat tended to have a thinner vessel wall than those harvested conventionally (MD [pedicle minus conventional] -0.057 mm, 95% CI: -0.12, +0.0037, p = .066, test for interaction p = .07). Lumen diameter was similar across groups (harvest comparison p = .81; pressure comparison p = .24). Low-pressure testing was associated with fewer hospital admissions in the 12 months following surgery (p = .0008). Harvesting the vein with the pedicle fat was associated with more complications during the index admission (p = .0041). CONCLUSIONS: Conventional saphenous vein graft preparation with low-pressure distension and harvesting the vein with a surrounding pedicle yielded similar graft wall thickness after 12 months, but low pressure was associated with fewer adverse events.

Biomimicking Covert Communication by Time-Frequency Shift Modulation for Increasing Mimicking and BER Performances.

Underwater acoustic (UWA) biomimicking communications have been developed for covert communications. For the UWA covert communications, it is difficult to achieve the bit error rate (BER) and the degree of mimic (DoM) performances at the same time. This paper proposes a biomimicking covert communication method to increase both BER and DoM (degree of mimic) performances based on the Time Frequency Shift Keying (TFSK). To increase DoM and BER performances, the orthogonality requirements of the time- and frequency-shifting units of the TFSK are theoretically derived, and the whistles are multiplied by the sequence with a large correlation. Two-step DoM assessments are also developed for the long-term whistle signals. Computer simulations and practical lake and ocean experiments demonstrate that the proposed method increases the DoM by 35% and attains a zero BER at -6 dB of Signal to Noise Ratio (SNR).

Machine Learning Based Biomimetic Underwater Covert Acoustic Communication Method Using Dolphin Whistle Contours.

For underwater acoustic covert communications, biomimetic covert communications have been developed using dolphin whistles. The conventional biomimetic covert communication methods transmit slightly different signal patterns from real dolphin whistles, which results in a low degree of mimic (DoM). In this paper, we propose a novel biomimetic communication method that preserves the large DoM with a low bit error rate (BER). For the transmission, the proposed method utilizes the various contours of real dolphin whistles with the link information among consecutive whistles, and the proposed receiver uses machine learning based whistle detectors with the aid of the link information. Computer simulations and practical ocean experiments were executed to demonstrate the better BER performance of the proposed method. Ocean experiments demonstrate that the BER of the proposed method was 0.002, while the BER of the conventional Deep Neural Network (DNN) based detector showed 0.36.

Optimal dose of dabigatran for the prevention of thromboembolism with minimal bleeding risk in Korean patients with atrial fibrillation.

AIMS: We aim to determine the optimal dose of dabigatran in Korean patients with atrial fibrillation (AF). METHODS AND RESULTS: We analysed 1834 patients with non-valvular AF, classified into a warfarin group (n = 990), dabigatran 150 mg group (D150, n = 294), and 110 mg group (D110, n = 550). The D110 group was further classified into patients concordant (co-D110, n = 367) and patients discordant (di-D110, n = 183) with guidelines to dose reduction. Propensity-matched 1-year clinical outcomes were then compared. Efficacy outcomes were defined as thromboembolism composed of new-onset stroke or systemic embolism. Safety outcomes were major bleeding. Both D150 and D110 had comparable efficacies as warfarin. However, only D110 significantly lowered the risk of major bleeding [hazard ratio (HR) 0.19, 95% confidence interval (CI) 0.07-0.55, P = 0.002]. In a subgroup analysis according to guideline-concordant indications for dose reduction, both co-D110 and di-D110 displayed a comparable efficacy as warfarin. Both co-D110 (HR 0.22, 95% CI 0.06-0.76, P = 0.017) and di-D110 (HR 0.11, 95% CI 0.02-0.81, P = 0.030) significantly lowered incidences of major bleeding. There were no differences in the efficacy and safety between di-D110 and D150, and net clinical outcomes were similar. CONCLUSION: Although D150 and D110 had a comparable efficacy, only D110 lowered the risk of major bleeding in Korean AF patients compared with warfarin. Even the guideline-discordant use of dabigatran 110 mg demonstrated a similar efficacy and safety compared with D150. However, further prospective randomized trials are needed in order to comprehensively evaluate whether D150 or D110 is the optimal dosage in Asian patients with AF.

Efficacy of single-dose evolocumab injection in early-phase acute myocardial infarction: a retrospective single-center study.

Background/Aims: Achieving rapid reduction of low-density lipoprotein cholesterol (LDL-C) levels below 55 mg/dL in patients with acute myocardial infarction (AMI) can be challenging with statins alone. This single-center, retrospective study aimed to assess the impact of single-dose injection of evolocumab 140 mg on LDL-C levels during the peri-percutaneous coronary intervention (PCI) period in patients with AMI. Methods: A total of 95 patients with AMI who underwent PCI were divided into the evolocumab (n = 50) and non-evolocumab (n = 45) groups. Results: The percentage change of LDL-C level at 1-3 weeks from baseline was 78.4 ± 13.4% reduction in the evolocumab group versus 45.6 ± 22.6% in the non-evolocumab group, with a mean difference of -33.5% between the groups (95% CI: -42.6 to -24.5%; p < 0.001). The achievement rate of LDL-C levels below 55 mg/dL at 1-3 weeks was significantly higher in the evolocumab group than in the non-evolocumab group (97.7% vs. 60.0%, p < 0.001). Conclusions: Patients with AMI who received single-dose injection of evolocumab 140 mg during the peri-PCI period had a significantly greater LDL-C reduction and higher proportion of patients achieved the target LDL-C level in the early phase AMI than those who did not receive evolocumab.

Diagnostic Performance of On-Site Automatic Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve.

BACKGROUND AND OBJECTIVES: Fractional flow reserve (FFR) is an invasive standard method to identify ischemia-causing coronary artery disease (CAD). With the advancement of technology, FFR can be noninvasively computed from coronary computed tomography angiography (CCTA). Recently, a novel simpler method has been developed to calculate on-site CCTA-derived FFR (CT-FFR) with a commercially available workstation. METHODS: A total of 319 CAD patients who underwent CCTA, invasive coronary angiography, and FFR measurement were included. The primary outcome was the accuracy of CT-FFR for defining myocardial ischemia evaluated with an invasive FFR as a reference. The presence of ischemia was defined as FFR ≤0.80. Anatomical obstructive stenosis was defined as diameter stenosis on CCTA ≥50%, and the diagnostic performance of CT-FFR and CCTA stenosis for ischemia was compared. RESULTS: Among participants (mean age 64.7±9.4 years, male 77.7%), mean FFR was 0.82±0.10, and 126 (39.5%) patients had an invasive FFR value of ≤0.80. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT-FFR were 80.6% (95% confidence interval [CI], 80.5-80.7%), 88.1% (95% CI, 82.4-93.7%), 75.6% (95% CI, 69.6-81.7%), 70.3% (95% CI, 63.1-77.4%), and 90.7% (95% CI, 86.2-95.2%), respectively. CT-FFR had higher diagnostic accuracy (80.6% vs. 59.1%, p<0.001) and discriminant ability (area under the curve from receiver operating characteristic curve 0.86 vs. 0.64, p<0.001), compared with anatomical obstructive stenosis on CCTA. CONCLUSIONS: This novel CT-FFR obtained from an on-site workstation demonstrated clinically acceptable diagnostic performance and provided better diagnostic accuracy and discriminant ability for identifying hemodynamically significant lesions than CCTA alone.

Intravascular ultrasound-guided versus angiography-guided percutaneous coronary intervention for acute myocardial infarction with cardiogenic shock.

The benefits of intravascular ultrasonography (IVUS)-guided percutaneous coronary intervention (PCI) in the clinical context of cardiogenic shock (CS) complicating acute myocardial infarction are lacking. We aimed to investigate the impact of IVUS-guided PCI in patients with AMI and CS. From the pooled data based on a series of Korean AMI registries during 2011-2020, we identified 1418 consecutive patients who underwent PCI with second generation drug-eluting stent (DES) for AMI and CS. The primary endpoint was the 1-year rate of target lesion failure (TLF), defined as the composite of cardiac death, target vessel myocardial infarction, and ischemic-driven target lesion revascularization. In total, 294 (20.7%) and 1124 (79.3%) underwent IVUS-guided and angiography-guided PCI with second generation DES implantation, respectively. The 1-year TLF was not significantly different between groups after IPTW analysis (hazard ratio 0.93, 95% confidence interval 0.65-1.34, p = 0.70). Additionally, the adjusted landmark analysis for TLF at 30 days and between 30 days and 1 year after PCI demonstrated no significant difference between the groups. In conclusion, in patients with AMI and CS who underwent PCI with second-generation DES, IVUS-guided PCI did not improve the 1-year TLF compared with angiography-guided PCI.Registration: URL:  http://cris.nih.go.kr . KCT0000863 and KCT0008355.

Distal Radial Access for Coronary Procedures in a Large Prospective Multicenter Registry: The KODRA Trial.

BACKGROUND: Distal radial access (DRA) as an alternative access route lacks evidence, despite its recent reputation. OBJECTIVES: The aim of this study was to evaluate the safety and feasibility of DRA on the basis of daily practice. METHODS: The KODRA (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach) trial was a prospective multicenter registry conducted at 14 hospitals between September 2019 and September 2021. The primary endpoints were the success rates of coronary angiography (CAG) and percutaneous coronary intervention (PCI). The secondary endpoints included successful distal radial artery puncture, access-site crossover, access site-related complications, bleeding events, and predictors of puncture failure. RESULTS: A total of 4,977 among 5,712 screened patients were recruited after the exclusion of 735 patients. The primary endpoints, the success rates of CAG and PCI via DRA, were 100% and 98.8%, respectively, among successful punctures of the distal radial artery (94.4%). Access-site crossover occurred in 333 patients (6.7%). The rates of distal radial artery occlusion and radial artery occlusion by palpation were 0.8% (36 of 4,340) and 0.8% (33 of 4,340) at 1-month follow-up. DRA-related bleeding events were observed in 3.3% of patients, without serious hematoma. Multilevel logistic regression analysis identified weak pulse (OR: 9.994; 95% CI: 7.252-13.774) and DRA experience <100 cases (OR: 2.187; 95% CI: 1.383-3.456) as predictors of puncture failure. CONCLUSIONS: In this large-scale prospective multicenter registry, DRA demonstrated high success rates of CAG and PCI, with a high rate of puncture success but low rates of distal radial artery occlusion, radial artery occlusion, bleeding events, and procedure-related complications. Weak pulse and DRA experience <100 cases were predictors of puncture failure. (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach [KODRA]; NCT04080700).

Invasive physiologic assessment of coronary artery stenosis by resting full-cycle ratio and fractional flow reserve: a prospective observational study.

Resting full-cycle ratio (RFR), an alternative to fractional flow reserve (FFR) for evaluating intermediate coronary artery stenosis, helps reduce patients' time, cost, and discomfort. However, the validation data for RFR and FFR are lacking. We aimed to assess the diagnostic accuracy of RFR and FFR and evaluate effective decision-making for revascularization using their values. Patients subjected to an invasive physiological study for intermediate coronary artery stenosis in Yongin Severance hospital between October 2020 and April 2022 were prospectively and consecutively recruited. We evaluated the correlation between RFR and FFR measurements and the diagnostic performance of RFR (≤ 0.89) versus FFR (≤ 0.80). In all, 474 intermediate coronary stenosis lesions from 400 patients were evaluated using RFR and FFR values. There was a strong linear relationship between RFR and FFR (r = 0.75, 95% CI 0.70-0.78, p < 0.01). Comparing diagnostic performance between RFR and FFR, RFR demonstrated diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 85.0%, 80.0%, 86.7%, 67.1%, and 92.7%, respectively. We analyzed the RFR value in the hyperemia zone (0.86-0.93) according to positive (RFR: 0.86-0.89) and negative (RFR: 0.90-0.93) areas. PPV in positive area is 47.8% (95% Confidence Interval [CI]: 33.8% to 62.0%) and NPV in negative area is 87.7% (95% CI: 80.3% to 93.1%). Excellent correlation exists between RFR and FFR and the diagnostic value of RFR without hyperemia compared with FFR in establishing the accurate functional significance of coronary artery stenosis was shown. RFR alone could evaluate the functional significance of coronary artery stenosis without unnecessary hyperemia, except in the positive area.Trial registration: URL: http://trialsearch.who.int ; Unique identifier: KCT0005255.

Comparison of spasmolytic regimen for prevention of radial artery spasm during the distal radial approach: A single-center, randomized study.

Background: The distal radial approach (DRA) for coronary catheterization is increasingly being used worldwide yet the optimal medication regimen to prevent radial artery spasm (RAS), an important factor for the success of the procedure, remains unclear. The aim of this study is to examine the effectiveness of medication for preventing RAS via the DRA. Methods: This was a prospective, comparative randomized study including 400 patients who underwent coronary catheterization via DRA in single center by three experienced DRA operators. Patients were randomized to either nitroglycerin (NTG) injection (N = 200) or NTG plus verapamil (N = 200) to compare the effectiveness and safety of these regimens. Results: There were no differences between the groups in the changes in radial artery diameter at most spastic area (0.34 ± 0.20 in the NTG group, 0.35 ± 0.20 in the NTG plus verapamil group; P = 0.73). There was no difference between the groups in the ratio of patients without arm pain during the procedure (95.0% in the NTG group, 93.5% in the NTG plus verapamil group; P = 0.67). However, there was a greater reduction in diastolic blood pressure in the NTG plus verapamil group (-8.3 ± 7.9 mmHg) than in the NTG group (-6.6 ± 7.6 mmHg) (P = 0.03). Conclusion: Intra-arterial injection of NTG as a single agent is effective and safe in the prevention of RAS during coronary catheterization via the DRA compared with a cocktail regimen of NTG plus verapamil. Clinical trial registration: https://cris.nih.go.kr, identifier KCT0005177.

A modified and rapid method for the single-well push-pull (SWPP) test using SF6, Kr, and uranine tracers.

In the present study, a single-well push-pull (SWPP) test was conducted with multi-component tracers, including inert gas (SF6 and Kr) and uranine (conservative), to understand the volatile/semi-volatile component transport characteristics in the groundwater system. In an SWPP test, it is essential to obtain an initial breakthrough curve (BTC) of the inert gas concentration at the beginning of the pulling stage to analyze the hydraulic properties of the groundwater system. As a result of the SWPP test using a proposed method in this study, physicochemical parameters of the groundwater and BTC of gas tracers and uranine were acquired simultaneously and successfully. In addition, on-site measurements of uranine, pCO2, and water quality data, such as electrical conductivity (EC), temperature, pH, and dissolved oxygen, were undertaken. Modification of an existing pCO2 measuring system allowed the gas samples to be collected, transported, and analyzed for inert gas components within a few hours. As a result, reliable and interpretable data with a recovery ratio of 26%, 85%, and 95% for SF6, Kr, and uranine, respectively, were obtained. The differences in the recovery ratio were utilized to identify the environmental system, whether it contains gas inside the isolated system (closed) or not (open), and to understand plume behavior characteristics in the experimental zone. By applying a two-dimensional advection-dispersion model to the acquired tracer test data and comparing the observed and computed tracer concentrations, helpful information was obtained on the hydraulic and transport characteristics of the targeted zone. This method can be extended to the design of dissolved CO2 transport monitoring of an aquifer above a CCS site.

An Automatic-Vertical Profile Monitoring System for Fresh-Saline Water Zones in Coastal Aquifer.

Coastal aquifers are complex systems governed by fresh-saline water interactions and ocean tidal effects. The vertical electrical conductivity (EC) and temperature (T) are general indicators for detecting the fresh-saline water interface (FSI) and sea water intrusion in groundwater wells located in coastal aquifers. In this method brief, we developed a cost-effective Arduino-based automatic-vertical profile monitoring system (A-VPMS) to continuously record vertical EC and T in groundwater wells, with the aim of testing its effectiveness in spatiotemporal monitoring of the FSI in a coastal aquifer located in eastern Korea. By analyzing the high-density EC and T data obtained by the A-VPMS, we evaluated the characteristics of the FSI, such as depth and spatial distribution. Our established EC and T data collection method using the A-VPMS proved to be efficient and reliable, providing an excellent tool for fine-scale temporal and spatial understanding of sea water intrusion. The results of this study demonstrate the potential of the A-VPMS for continuous monitoring of the FSI in coastal aquifers, which is crucial for sustainable management of groundwater resources.

Impact of intravascular ultrasound in acute myocardial infarction patients at high ischemic risk.

INTRODUCTION AND OBJECTIVES: Evidence for the role of intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in patients at high ischemic risk of acute myocardial infarction (AMI) is lacking. This study aimed to investigate the long-term clinical impact of IVUS-guided PCI in patients at high ischemic risk of AMI. METHODS: Among 13 104 patients with AMI enrolled in the Korea Acute Myocardial Infarction Registry-National Institutes of Health, we selected 8890 patients who underwent successful PCI with second-generation drug-eluting stent implantation and classified them into 2 groups based on whether or not they were at high ischemic risk or not, defined as any of the following: number of stents implanted ≥ 3, 3 vessels treated, ≥ 3 lesions treated, total stent length> 60mm, left main PCI, diabetes mellitus, and chronic kidney disease. The primary outcome was target lesion failure including cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization at 3 years. RESULTS: In 4070 AMI patients at high ischemic risk, IVUS-guided PCI (21.6%) was associated with a significantly lower risk of target lesion failure at 3 years (6.7% vs 12.0%; HR, 0.54; 95%CI, 0.41-0.72; P <.001) than angiography-guided PCI. The results were consistent after confounder adjustment, inversed probability weighting, and propensity score matching. CONCLUSIONS: In patients at high ischemic risk of AMI who underwent PCI with second-generation drug-eluting stent implantation, use of IVUS guidance was associated with a significant reduction in 3-year target lesion failure. iCreaT study No. C110016.

Optical coherence tomography-guided versus intravascular ultrasound-guided percutaneous coronary intervention in patients with acute myocardial infarction.

INTRODUCTION AND OBJECTIVES: Optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) yields clinical outcomes comparable to intravascular ultrasound (IVUS)-guided PCI in patients with stable ischemic heart disease. However, there is a scarcity of data comparing the clinical outcomes of OCT-guided and IVUS-guided PCI in the setting of acute myocardial infarction (AMI). We sought to compare the clinical outcomes of OCT-guided vs IVUS-guided PCI for patients with AMI in the era of second-generation drug-eluting stent (DES). METHODS: We identified 5260 consecutive patients who underwent PCI with a second-generation DES for AMI under IVUS or OCT guidance from pooled data derived from a series of Korean AMI registries between 2011 and 2020. The primary endpoint was the 1-year rate of target lesion failure, defined as a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization. RESULTS: A total of 535 (10.2%) and 4725 (89.8%) patients were treated under OCT and IVUS guidance, respectively. The 1-year target lesion failure rates were comparable between the OCT and IVUS groups before and after propensity score matching (hazard ratio, 0.92; 95%CI, 0.42-2.05, P=.84). The OCT utilization rate did not exceed 5% of total patients treated with second-generation DES implantation during the study period. The primary factors for the selection of OCT over IVUS were the absence of chronic kidney disease, non-left main vessel disease, single-vessel disease, stent diameter <3mm, and stent length ≤ 25mm. CONCLUSIONS: OCT-guided PCI in patients with AMI treated with a second-generation DES provided comparable clinical outcomes for 1-year target lesion failure compared with IVUS-guided PCI.

Early Invasive Strategy Based on the Time of Symptom Onset of Non-ST-Segment Elevation Myocardial Infarction.

BACKGROUND: A limitation of the current guidelines regarding the timing of invasive coronary angiography for patients with non-ST-segment elevation acute coronary syndrome is the randomization time. To date, no study has reported the clinical outcomes of invasive strategy timing on the basis of the time of symptom onset. OBJECTIVES: The aim of this study was to investigate the effect of invasive strategy timing from the time of symptom onset on the 3-year clinical outcomes of patients with non-ST-segment elevation myocardial infarction (NSTEMI). METHODS: Among 13,104 patients from the Korea Acute Myocardial Infarction Registry-National Institutes of Health, 5,856 patients with NSTE myocardial infarction were evaluated. The patients were categorized according to symptom-to-catheter (StC) time (<48 or ≥48 hours). The primary outcome was 3-year all-cause mortality. RESULTS: Overall, 3,919 patients (66.9%) were classified into the StC time <48 hours group. This group had lower all-cause mortality than the group with StC time ≥48 hours (7.3% vs 13.4%; P < 0.001). The lower risk for all-cause mortality in the group with StC time <48 hours group was consistent in all subgroups. Notably, emergency medical service use (HR: 0.31; 95% CI: 0.19-0.52) showed a lower risk for all-cause mortality than no emergency medical service use (HR: 0.54; 95% CI: 0.46-0.65; P value for interaction = 0.008). CONCLUSIONS: An early invasive strategy on the basis of StC time was associated with a decreased risk for all-cause mortality in patients with NSTEMI. Because the study was based on a prospective registry, the results should be considered hypothesis generating, highlighting the need for further research. (iCReaT Study No. C110016).

Successful Primary Percutaneous Coronary Intervention without Stenting: Insight from Optimal Coherence Tomography.

For patients with acute myocardial infarction, current management guidelines recommend implantation of a drug-eluting stent, dual antiplatelet therapy (including potent P2Y12 inhibitors) for at least 1 year, and maintenance of life-long antiplatelet therapy. However, a pilot study showed favorable results with antithrombotic therapy without stent implantation when plaque erosion, not definite plaque rupture, was confirmed using optical coherence tomography (OCT), despite the patients having acute myocardial infarction. Here, we present a case where successful primary percutaneous coronary intervention was performed without stenting with the aid of OCT in a patient with ST-elevation myocardial infarction who developed thrombotic total occlusion of the right coronary artery.