The Role of Index of Microcirculatory Resistance in Left Anterior Descending Artery ST Segment Elevation Myocardial Infarction Patients after Primary Percutaneous Coronary Intervention.

Background: Our aim was to assess the relationship of the index of microvascular resistance (IMR) in left anterior descending (LAD) artery involved STEMI patients. Methods: Data of 316 STEMI patients who had undergone primary percutaneous coronary intervention (PCI) were collected from three cardiovascular centers from 2005 to 2015. In total, 246 patients with LAD STEMI were enrolled for IMR evaluation. Patients were divided into two groups respective of the cut-off IMR value of 30. All-cause mortality, left ventricular function, improvement of systolic function, and cardiac biomarkers were analyzed and compared. Results: A total of 246 patients were enrolled. The number of patients in the IMR above 30 group was 93 and below 30 was 153. The mean ages for each group were 57.91 ± 11.99 and 54 ± 10.63, respectively. The peak creatinine kinase (CK) (3936.85 ± 2827.32 IU/L vs. 2218.08 ± 2310.41 IU/L, p < 0.001) and CKmb (336.15 ± 195.08 mg/mL vs. 231.53 ± 179.53 mg/mL, p < 0.001) levels were higher for an IMR above the 30 group. The left ventricular ejection fraction (LVEF) (44.57 ± 6.685% vs. 47.35 ± 8.17%, p = 0.006) and improvement of LVEF (2.81 ± 7.135% vs. 5.88 ± 7.65%, p = 0.004) was lower in the IMR above 30 group. All-cause mortality (7.5% vs. 1.3%, p = 0.012) was higher in the IMR above 30 group, and a Cox regression analysis showed that an IMR above 30 was a poor prognostic factor regarding all-cause mortality (HR: 5.151, 95% CI 1.062-24.987, p = 0.042) even after adjusting for classical clinical risk factors. Conclusions: An elevated IMR value represented larger infarct size, more severe LV dysfunction, and higher mortality in LAD STEMI patients after successful PCI.

Prognostic Implications of Quantitative Flow Ratio and Plaque Characteristics in Intravascular Ultrasound-Guided Treatment Strategy.

BACKGROUND: Quantitative flow ratio (QFR) is a method for evaluating fractional flow reserve without the use of an invasive coronary pressure wire or pharmacological hyperemic agent. OBJECTIVES: The aim of this study was to investigate the prognostic implications of QFR and plaque characteristics in patients who underwent intravascular ultrasound (IVUS)-guided treatment for intermediate lesions. METHODS: Among the IVUS-guided strategy group in the FLAVOUR (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients with Intermediate Stenosis) trial, vessels suitable for QFR analysis were included in this study. High-risk features were defined as low QFR (≤0.90), quantitative high-risk plaque characteristics (qn-HRPCs) (minimal lumen area ≤3.5 mm2, or plaque burden ≥70%), and qualitative high-risk plaque characteristics (ql-HRPCs) (attenuated plaque, positive remodeling, or plaque rupture) assessed using IVUS. The primary clinical endpoint was target vessel failure (TVF), defined as a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization. RESULTS: A total of 415 (46.1%) vessels could be analyzable for QFR. The numbers of qn-HRPCs and ql-HRPCs increased with decreasing QFR. Among deferred vessels, those with 3 high-risk features exhibits a significantly higher risk of TVF compared with those with ≤2 high-risk features (12.0% vs 2.7%; HR: 4.54; 95% CI: 1.02-20.29). CONCLUSIONS: Among the IVUS-guided deferred group, vessels with qn-HRPC and ql-HRPC with low QFR (≤0.90) exhibited a significantly higher risk for TVF compared with those with ≤2 features. Integrative assessment of angiography-derived fractional flow reserve and anatomical and morphological plaque characteristics is recommended to improve clinical outcomes in patients undergoing IVUS-guided deferred treatment.

Physiology- or Imaging-Guided Strategies for Intermediate Coronary Stenosis.

Importance: Treatment strategies for intermediate coronary lesions guided by fractional flow reserve (FFR) and intravascular ultrasonography (IVUS) have shown comparable outcomes. Identifying low-risk deferred vessels to ensure the safe deferral of percutaneous coronary intervention (PCI) and high-risk revascularized vessels that necessitate thorough follow-up can help determine optimal treatment strategies. Objectives: To investigate outcomes according to treatment types and FFR and IVUS parameters after FFR- or IVUS-guided treatment. Design, Setting, and Participants: This cohort study included patients with intermediate coronary stenosis from the Fractional Flow Reserve and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients With Intermediate Stenosis (FLAVOUR) trial, an investigator-initiated, prospective, open-label, multicenter randomized clinical trial that assigned patients into an IVUS-guided strategy (which recommended PCI for minimum lumen area [MLA] ≤3 mm2 or 3 mm2 to 4 mm2 with plaque burden [PB] ≥70%) or an FFR-guided strategy (which recommended PCI for FFR ≤0.80). Data were analyzed from November to December 2022. Exposures: FFR or IVUS parameters within the deferred and revascularized vessels. Main Outcomes and Measures: The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, and revascularization at 2 years. Results: A total of 1619 patients (mean [SD] age, 65.1 [9.6] years; 1137 [70.2%] male) with 1753 vessels were included in analysis. In 950 vessels for which revascularization was deferred, incidence of TVF was comparable between IVUS and FFR groups (3.8% vs 4.1%; P = .72). Vessels with FFR greater than 0.92 in the FFR group and MLA greater than 4.5 mm2 or PB of 58% or less in the IVUS group were identified as low-risk deferred vessels, with a decreased risk of TVF (hazard ratio [HR], 0.25 [95% CI, 0.09-0.71]; P = .009). In 803 revascularized vessels, the incidence of TVF was comparable between IVUS and FFR groups (3.6% vs 3.7%; P = .95), which was similar in the revascularized vessels undergoing PCI optimization (4.2% vs 2.5%; P = .31). Vessels with post-PCI FFR of 0.80 or less in the FFR group or minimum stent area of 6.0 mm2 or less or with PB at stent edge greater than 58% in the IVUS group had an increased risk for TVF (HR, 7.20 [95% CI, 3.20-16.21]; P < .001). Conclusions and Relevance: In this cohort study of patients with intermediate coronary stenosis, FFR- and IVUS-guided strategies showed comparable outcomes in both deferred and revascularized vessels. Binary FFR and IVUS parameters could further define low-risk deferred vessels and high-risk revascularized vessels.

Clinical Outcomes of Deferred Lesions by IVUS Versus FFR-Guided Treatment Decision.

BACKGROUND: There are limited data regarding the safety of deferral of percutaneous coronary intervention based on intravascular ultrasound (IVUS) findings. The current study sought to compare the prognosis between deferred lesions based on IVUS and fractional flow reserve (FFR)-guided treatment decision. METHODS: This study is a post hoc analysis of the FLAVOUR randomized trial (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients With Intermediate Stenosis) that compared 2-year clinical outcomes between IVUS- and FFR-guided treatment decision on intermediate coronary artery lesions using predefined criteria. In both IVUS and FFR groups, vessels were classified into deferred or revascularized vessels, and patients were classified as those with or without deferred lesions. Vessel-oriented composite outcomes (cardiac death, target vessel myocardial infarction, or target vessel revascularization) in deferred vessels and patient-oriented composite outcomes (death, myocardial infarction, or any revascularization) in patients with deferred lesions were compared between the IVUS and FFR groups. RESULTS: A total of 1682 patients and 1820 vessels were analyzed, of which 922 patients and 989 vessels were deferred. At 2 years, there was no difference in the cumulative incidence of vessel-oriented composite outcomes in deferred vessels between IVUS (n=375) and FFR (n=614) groups (3.8% versus 4.1%; hazard ratio, 0.91 [95% CI, 0.47-1.75]; P=0.77). The risk of vessel-oriented composite outcomes was comparable between deferred and revascularized vessels following treatment decision by IVUS (3.8% versus 3.5%; hazard ratio, 1.09 [95% CI, 0.54-2.19]; P=0.81) and FFR (4.1% versus 3.6%; hazard ratio, 1.14 [95% CI, 0.56-2.32]; P=0.72). In comparison of patient-oriented composite outcomes in patients with deferred lesions, there was no significant difference between the IVUS (n=357) and FFR (n=565) groups (6.2% versus 5.9%; hazard ratio, 1.05 [95% CI, 0.61-1.80]; P=0.86). CONCLUSIONS: In patients with intermediate coronary artery stenosis, deferral of percutaneous coronary intervention based on IVUS-guided treatment decision showed comparable risk of clinical events with FFR-guided treatment decision. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02673424.

Sustained beneficial effect of ß-blockers on clinical outcomes after discontinuation in patients with ST elevation myocardial infarction.

Our previous study demonstrated that beneficial effect of ß-blockers on clinical outcomes in patients with ST elevation myocardial infarction (STEMI). In clinical practice, ß-blocker treatment is occasionally discontinued due to their side effect. The purpose of this study is to assess the impact of discontinuation of ß-blockers on long-term clinical outcomes in patients with STEMI. We analyzed the data and clinical outcomes of 901 patients (716 males, 58 ± 13-year-old) STEMI patients who underwent successful primary percutaneous coronary intervention. At discharge of index STEMI, 598 patients were treated with ß-blockers (491 males, 56 ± 12-year-old). After more than 1-month ß-blocker treatment, ß-blockers were stopped in 188 patients for any reason. We classified patients into continuation of ß-blockers (410 patients, 56 ± 12-year-old) and discontinuation of ß-blockers groups (188 patients, 57 ± 11-year-old) according to discontinuation of ß-blockers. Occurrence of major adverse cardiovascular events (MACEs; death, recurrent MI and target vessel revascularization) during up to 10 years of follow-up was evaluated. Mean follow-up month was 56 ± 28 month. In 132 patients (22%), MACEs were occurred. The MACE-free survival rates in the 2 groups were not statistically different (log-rank P = .461). Adjusted hazard ratio (HR) of discontinuation of ß-blockers for MACEs was 1.006 (95% confidence interval (CI) 0.701-1.445, P = .973; all cause of death, HR = 0.942, 95% CI = 0.547-1.622, P = .828; recurrent MI, HR = 0.476, 95% CI = 0.179-1.262, P = .136; target vessel revascularization, HR = 1.417, 95% CI = 0.865-2.321, P = .166). The MACE-free survival and survival rates of the non ß-blockers treatment group was significantly worse than the discontinuation of ß-blockers group (log-rank P = .003 and < 0.001, respectively). This study demonstrated that discontinuation of ß-blockers was not associated with adverse cardiovascular outcomes after STEMI. The beneficial effect of ß-blockers on clinical outcomes may persist in patients with initial ß-blockers treatment at index STEMI.

Sex Differences in Fractional Flow Reserve- or Intravascular Ultrasound-Guided Percutaneous Coronary Intervention.

BACKGROUND: A recent randomized trial reported fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) strategy was noninferior to the intracoronary ultrasound (IVUS)-guided PCI strategy with respect to clinical outcomes with fewer revascularizations. OBJECTIVES: This study sought to investigate the sex differences in treatment and clinical outcomes according to physiology- or imaging-guided PCI strategies. METHODS: In this secondary analysis of the FLAVOUR (Fractional Flow Reserve or Intravascular Ultrasonography to Guide PCI) trial, the impact of sex on procedural characteristics, PCI rate, and outcomes according to different strategies and treatment types (PCI vs deferral of PCI) was analyzed. The primary outcome was target vessel failure (TVF) at 24 months, defined as a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization. RESULTS: Of 1,619 patients, 30% were women. Compared with men, women had a smaller minimal lumen area, smaller plaque burden, and higher FFR. They had a lower PCI rate (40.8% vs 47.9%; P = 0.008), which was mainly contributed by FFR guidance. Overall, women showed a lower TVF rate (2.4% vs 4.5%). According to the treatment type, the cumulative incidence of TVF was lower in women than in men among those with the deferral of PCI (1.7% vs 5.2%). However, this trend was not observed in patients who underwent PCI. In both women and men, there were no differences in clinical outcomes between the FFR- and IVUS-guided strategies. CONCLUSIONS: In cases of intermediate stenosis, despite receiving fewer interventions, women had more favorable outcomes than men. The use of FFR led to a lower PCI rate but had a similar prognostic value compared with IVUS in both women and men.

Impact of height difference between coronary ostium and location of intracoronary pressure sensor on fractional flow reserve measurements.

BACKGROUND: During fractional flow reserve (FFR) measurements, distal coronary pressure (Pd) can be influenced by hydrostatic pressure changes resulting from the height difference (HD) between the coronary ostium and the location of the distal pressure sensor. AIMS: We investigated the effect of aortocoronary HD on the FFR measurements in each coronary artery. METHODS: In this retrospective cohort study, we analyzed 257 patients who underwent FFR measurements and coronary computed tomography (CCTA) within a year. Using CCTA, we measured HD as the vertical distance between the coronary ostium and a matched point of the distal coronary pressure sensor identified on coronary angiography. RESULTS: The location of the Pd sensor was higher than the coronary ostium in the left anterior descending artery (LAD) (-4.64 ± 1.15 cm) and lower than the coronary ostium in the left circumflex artery (LCX) (2.54 ± 1.05 cm) and right coronary artery (RCA) (2.03 ± 1.28 cm). The corrected FFR values by HD were higher in the LAD (0.78 ± 0.09 to 0.82 ± 0.09, P<0.01) and lower in the LCX and RCA than the original FFR values (0.87 ± 0.07 to 0.85 ± 0.08, P<0.01; 0.87 ± 0.10 to 0.86 ± 0.10, P<0.01, respectively). Using an FFR cut-off value of 0.8, the concordance rates between the FFR and corrected FFR values were 77.8%, 95.2%, and 100% in the LAD, LCX, and RCA, respectively. CONCLUSION: HD between the coronary ostium and the distal coronary pressure sensor may affect FFR measurements and FFR-guided treatment decisions for coronary artery disease.

Epicardial Adipose Tissue Thickness Is Related to Plaque Composition in Coronary Artery Disease.

(1) Background: Currently, limited data are available regarding the relationship between epicardial fat and plaque composition. The aim of this study was to assess the relationship between visceral fat surrounding the heart and the lipid core burden in patients with coronary artery diseases; (2) Methods: Overall, 331 patients undergoing coronary angiography with combined near-infrared spectroscopy and intravascular ultrasound imaging were evaluated for epicardial adipose tissue (EAT) thickness using transthoracic echocardiography. Patients were divided into thick EAT and thin EAT groups according to the median value; (3) Results: There was a positive correlation between EAT thickness and maxLCBI4mm, and maxLCBI4mm was significantly higher in the thick EAT group compared to the thin EAT group (437 vs. 293, p < 0.001). EAT thickness was an independent predictor of maxLCBI4mm ≥ 400 along with age, low-density lipoprotein-cholesterol level, acute coronary syndrome presentation, and plaque burden in a multiple linear regression model. Receiver operating characteristic curve analysis showed that EAT thickness was a predictor for maxLCBI4mm ≥ 400; (4) Conclusions: In the present study, EAT thickness is related to the lipid core burden assessed by NIRS-IVUS in patients with CAD which suggests that EAT may affect the stability of the plaques in coronary arteries.

Fractional Flow Reserve or Intravascular Ultrasonography to Guide PCI.

BACKGROUND: In patients with coronary artery disease who are being evaluated for percutaneous coronary intervention (PCI), procedures can be guided by fractional flow reserve (FFR) or intravascular ultrasonography (IVUS) for decision making regarding revascularization and stent implantation. However, the differences in clinical outcomes when only one method is used for both purposes are unclear. METHODS: We randomly assigned 1682 patients who were being evaluated for PCI for the treatment of intermediate stenosis (40 to 70% occlusion by visual estimation on coronary angiography) in a 1:1 ratio to undergo either an FFR-guided or IVUS-guided procedure. FFR or IVUS was to be used to determine whether to perform PCI and to assess PCI success. In the FFR group, PCI was to be performed if the FFR was 0.80 or less. In the IVUS group, the criteria for PCI were a minimal lumen area measuring either 3 mm2 or less or measuring 3 to 4 mm2 with a plaque burden of more than 70%. The primary outcome was a composite of death, myocardial infarction, or revascularization at 24 months after randomization. We tested the noninferiority of the FFR group as compared with the IVUS group (noninferiority margin, 2.5 percentage points). RESULTS: The frequency of PCI was 44.4% among patients in the FFR group and 65.3% among those in the IVUS group. At 24 months, a primary-outcome event had occurred in 8.1% of the patients in the FFR group and in 8.5% of those in the IVUS group (absolute difference, -0.4 percentage points; upper boundary of the one-sided 97.5% confidence interval, 2.2 percentage points; P = 0.01 for noninferiority). Patient-reported outcomes as reported on the Seattle Angina Questionnaire were similar in the two groups. CONCLUSIONS: In patients with intermediate stenosis who were being evaluated for PCI, FFR guidance was noninferior to IVUS guidance with respect to the composite primary outcome of death, myocardial infarction, or revascularization at 24 months. (Funded by Boston Scientific; FLAVOUR ClinicalTrials.gov number, NCT02673424.).

Stent dislodgement force of drug-eluting coronary stents: a bench test.

Background: Coronary stent dislodgement can cause critical complications. The dislodgement force of coronary drug-eluting stents (DES) remains unknown. This study aimed to compare the dislodgement force and pattern of contemporary DES. Methods: Five DES designs which commonly used in clinical practice were tested. The force at which the stent dislodges relative to the balloon was measured. For the shim test, peak displacement force, defined as the first peak force that occurs during stent displacement and peak dislodgement force, defined as the peak force required to completely dislodge the stent from the delivery system, were measured. Three examples of each of the stents were tested using the shim test. Results: The peak displacement force of Orsiro (3.1±0.8 N) was lower than that of Xience Sierra (5.8±0.5 N) [Firehawk 3.8±0.2 N, Resolute Onyx 4.5±1.5 N, Synergy 4.8±0.5 N (P=0.024)]. The peak dislodgement force was lowest in Orsiro (3.2±0.8 N) when compared to the other stents (Firehawk 6.6±0.6 N, Resolute Onyx 7.4±0.3 N, Synergy 11.8±0.4 N, Xience Sierra 11.1±1.6 N) (P<0.001); this remained significant in the multiple comparison analysis. During pullback of the stents, most stents buckled without removal. However, the whole Orsiro stent was completely removed from the delivery system. Conclusions: The dislodgement force of DESs differed between stent designs. The Orsiro stent was lower than that of other DES; additionally, it easily removed the whole stent from the delivery system. During the coronary intervention, operators should consider stent design and be cautious when pulling DES back in lesions with calcifications or a previously implanted stent, which are at high risk for stent dislodgement.

Efficacy and Safety of 3 Versus 6 Months of Dual-Antiplatelet Therapy in Patients Implanted With a Coroflex ISAR Stents: A Prospective, Multicenter, Randomized Clinical Trial.

BACKGROUND: The optimal duration of dual-antiplatelet therapy (DAPT) after implantation of a drug-eluting stent (DES), especially recently developed polymer-free DESs, is unknown. This study examined the efficacy and safety of 3- versus 6-month DAPT in patients implanted with Coroflex ISAR polymer-free DESs. METHODS: Between May 2015 and August 2020, 488 patients who underwent Coroflex ISAR stent implantation were enrolled in the study and randomly assigned to the 3-month (n=244) or 6-month (n=244) DAPT group. RESULTS: At 1 year, the primary endpoint (composite of cardiovascular death, myocardial infarction, target vessel revascularization, and Bleeding Academic Research Consortium [BARC] type 2-5 bleeding) occurred in 9 (3.7%) patients in the 3-month DAPT group and in 7 (2.9%) patients in the 6-month DAPT group (hazard ratio 1.31; P=.60). There was no difference between the 3- and 6-month DAPT groups in either BARC type 2-5 bleeding (1.6% vs 0.8%; hazard ratio 2.00; P=.42) or any bleeding (2.9% vs 3.3%; hazard ratio 0.87; P=.80). CONCLUSION: Compared with 6 months of DAPT, 3 months of DAPT did not increase the risk of primary endpoint 1 year after Coroflex ISAR stent implantation, although it should be noted that the trial has limited power to see differences due to low event rate and low recruitment rate.

The Index of Microcirculatory Resistance after Primary Percutaneous Coronary Intervention Predicts Long-Term Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction.

The index of microcirculatory resistance (IMR) is a simple method that can measure microvascular function after primary percutaneous coronary intervention (PCI) in patients with ST-segment Elevation Myocardial Infarction (STEMI). This study is to find out whether IMR predicts clinical long-term outcomes in STEMI patients. A total of 316 patients with STEMI who underwent primary PCI from 2005 to 2015 were enrolled. The IMR was measured using pressure sensor/thermistor-tipped guidewire after primary PCI. The primary endpoint was the rate of death or hospitalization for heart failure (HF) over a mean follow-up period of 65 months. The mean corrected IMR was 29.4 ± 20.0. Patients with an IMR > 29 had a higher rate of the primary endpoint compared to patients with an IMR ≤ 29 (10.3% vs. 2.1%, p = 0.001). During the follow-up period, 13 patients (4.1%) died and 6 patients (1.9%) were hospitalized for HF. An IMR > 29 was associated with an increased risk of death or hospitalization for HF (OR 5.378, p = 0.004). On multivariable analysis, IMR > 29 (OR 3.962, p = 0.022) remained an independent predictor of death or hospitalization for HF with age (OR 1.048, p = 0.049) and symptom-to-balloon time (OR 1.002, p = 0.049). High IMR was an independent predictor for poor long-term clinical outcomes in STEMI patients after primary PCI.

Reliability and validity of the Korean version of the MacNew heart disease Health-related Quality of Life questionnaire.

BACKGROUND: Myocardial infarction and unstable angina are prevalent in Korea. The MacNew Heart Disease health-related quality of life questionnaire is a widely used patient-reported outcome measure for patients with heart disease in several countries. In this study, we tested the validity and reliability of the Korean version of the MacNew (K-MacNew). METHODS: Participants were 200 patients who had experienced unstable angina or myocardial infarction, and were recruited from a tertiary hospital in Korea. The K-MacNew was developed using forward-backward translation techniques. Construct validity (including discriminative validity), concurrent validity, and internal consistency reliability of the K-MacNew were assessed. Discriminative validity was assessed by examining the between-group differences in the K-MacNew scores according to functional capacity, anxiety, and depression levels. Concurrent validity was examined by correlating the K-MacNew dimensions with the physical and mental health domains of the 36-item Short Form Health Survey Instrument (SF-36). RESULTS: Factor analysis results of the K-MacNew demonstrated a three-factor structure (emotional, physical, and social) that explained 57.92% of the variance. Significant differences in the K-MacNew scores were observed according to patients' functional capacity, anxiety, and depression levels. The SF-36 physical health domain score showed a moderate positive correlation with the physical dimension score of the K-MacNew (r = 0.517, P < 0.001), and the SF-36 mental health domain score showed a strong positive correlation with the emotional dimension of K-MacNew (r = 0.745, P < 0.001). The K-MacNew showed good internal consistency, with a Cronbach's α of 0.947 for the global scale. CONCLUSION: The K-MacNew demonstrated good reliability and validity for use as a patient-reported outcome measure and is ready for the assessment of the health-related quality of life of patients with coronary artery disease in Korea. To establish the clinical validity of the K-MacNew, additional studies should be conducted to verify the validity and reliability of the K-MacNew in a number of participants, including those with various types of coronary artery disease.

Translesional Fractional Flow Reserve is Related to Plaque Components in Coronary Artery Disease: A Study Combining Pressure Wire and NIRS-IVUS Analysis.

OBJECTIVES: It remains unclear whether atherosclerotic plaque structure or composition is related to translesional biomechanical stresses in coronary artery disease. The aim of this study was to evaluate the association between translesional pressure parameters (using a pressure wire) and plaque characteristics (using a combined near-infrared spectroscopy [NIRS] and intravascular ultrasound [IVUS] imaging catheter). METHODS: Fractional flow reserve (FFR), delta (Δ) FFR, and Δ pressure were obtained during adenosine-induced maximum hyperemic status. Lipid core burden index (LCBI) and maximum LCBI within 2 mm (maxLCBI2mm) and tomographic anatomy were evaluated by NIRS-IVUS. RESULTS: Sixty-six lesions from 57 patients were analyzed (57 lesions for FFR, 45 lesions for ΔFFR). There was a negative correlation between FFR and maxLCBI2mm (r=-0.264; P=.049) and a positive correlation between ΔFFR and maxLCBI2mm (r=0.299; P=.049). ΔFFR of lesions with maxLCBI2mm ≥500 was significantly higher than maxLCBI2mm <500 (0.159 ± 0.085 vs 0.104 ± 0.075, respectively; P=.04). By receiver-operating characteristic curve analysis, ΔFFR ≥0.1 was a predictor for maxLCBI2mm ≥500 (area under curve, 0.707; 95% confidence interval, 0.552-0.862; P=.03). On multivariate analysis, ΔFFR was the only predictor of maxLCBI2mm (ß=0.347; P=.03). CONCLUSION: ΔFFR across a coronary artery lesion is related to lipid core burden assessed using NIRS-IVUS and might be a meaningful predictor of high-risk plaque (plaque with high lipid content).

Five-year clinical outcomes of the first Korean-made sirolimus-eluting coronary stent with abluminal biodegradable polymer.

ABSTRACT: This study evaluated the 5-year clinical outcomes of the Genoss DES, the first Korean-made sirolimus-eluting coronary stent with abluminal biodegradable polymer.We previously conducted the first-in-patient prospective, multicenter, randomized trial with a 1:1 ratio of patients using the Genoss DES and Promus Element stents; the angiographic and clinical outcomes of the Genoss DES stent were comparable to those of the Promus Element stent. The primary endpoint was major adverse cardiac events (MACE), which was a composite of death, myocardial infarction (MI), and target lesion revascularization (TLR) at 5 years.We enrolled 38 patients in the Genoss DES group and 39 in the Promus Element group. Thirty-eight patients (100%) from the Genoss DES group and 38 (97.4%) from the Promus Element group were followed up at 5 years. The rates of MACE (5.3% vs 12.8%, P = .431), death (5.3% vs 10.3%, P = .675), TLR (2.6% vs 2.6%, P = 1.000), and target vessel revascularization (TVR) (7.9% vs 2.6%, P = .358) at 5 years did not differ significantly between the groups. No TLR or target vessel revascularization was reported from years 1 to 5 after the index procedure, and no MI or stent thrombosis occurred in either group during 5 years.The biodegradable polymer Genoss DES and durable polymer Promus Element stents showed comparable low rates of MACE at the 5-year clinical follow-up.

Influence of lesion and disease subsets on the diagnostic performance of the quantitative flow ratio in real-world patients.

The quantitative flow ratio (QFR) is a novel angiography-based computational method assessing functional ischemia caused by coronary stenosis. This study aimed to evaluate the diagnostic performance of quantitative flow ratio (QFR) in patients with angina and acute myocardial infarction (AMI) and to identify the conditions with low diagnostic performance. We assessed the QFR for 1077 vessels under fractional flow ratio (FFR) evaluation in 915 patients with angina and AMI. The diagnostic accuracies of the QFR for identifying an FFR ≤ 0.8 were 95.98% (95% confidence interval [CI] 94.52 to 97.14%) for the angina group and 92.42% (95% CI 86.51 to 96.31%) for the AMI group. The diagnostic accuracy of the QFR in the borderline FFR zones (> 0.75, ≤ 0.85) (91.23% [95% CI 88.25 to 93.66%]) was significantly lower than that in others (difference: 4.32; p = 0.001). The condition accompanying both AMI and the borderline FFR zone showed the lowest QFR diagnostic accuracy in our data (83.93% [95% CI 71.67 to 92.38]). The diagnostic accuracy was reduced for tandem lesions (p = 0.04, not correcting for multiple testing). Our study found that the QFR method yielded a high overall diagnostic performance in real-world patients. However, low diagnostic accuracy has been observed in borderline FFR zones with AMI, and the hybrid FFR approach needs to be considered.

Managing Nonagenarians with Acute Myocardial Infarction: Invasive versus Conservative Treatment.

BACKGROUND: Limited data are available to support an invasive treatment strategy in nonagenarians with acute myocardial infarction (AMI). We aimed to investigate whether percutaneous coronary intervention (PCI) is beneficial in this frail population. METHODS: We retrospectively analyzed 41 nonagenarians with AMI (both ST-segment-elevation and non-ST-segment-elevation MI) between 2006 and 2015 in a single center. We assessed 30-day and one-year mortality rates according to the treatment strategy. RESULTS: Among study subjects, 24 (59%) were treated with PCI (PCI group) and 17 (41%) were treated with conservative management (medical treatment group) per the clinician's discretion. The median follow-up duration was 30 months (0-74 months). Thirty-day mortality was lower in the PCI group than in the medical treatment group (17% vs. 65%; P < 0.001). One-year mortality was also lower in the PCI group than in the medical treatment group (21% vs. 76%; P < 0.001). The PCI group presented a 73% decreased risk of death (adjusted hazard ratio: 0.269; 95% confidence interval: 0.126-0.571; P < 0.001). In the Killip class 1 through 3 subgroups (n = 36), 30-day and one-year mortality were still higher among those in the medical treatment group (13% vs. 54% at 30 days; P < 0.001 and 17% vs. 69% at one year; P < 0.001). Landmark analysis after 30 days revealed no significant difference in the cumulative mortality rate between the two groups, indicating that the mortality difference was mainly determined within the first 30 days after AMI. CONCLUSION: Mortality after AMI was decreased in correlation with the invasive strategy relative to the conservative strategy, even in nonagenarians. Regardless of age, PCI should be considered in AMI patients. However, large-scale randomized controlled trials are needed to support our conclusion.

Comparison of three-dimensional quantitative coronary angiography and intravascular ultrasound for detecting functionally significant coronary lesions.

BACKGROUND: Three-dimensional quantitative coronary angiography (3D-QCA) can provide more accurate measurement of true vessel size and may be comparable to intravascular ultrasound (IVUS) in identifying functionally significant coronary stenosis, as determined by fractional flow reserve (FFR). This study aimed to evaluate the diagnostic accuracy of 3D-QCA for predicting FFR <0.8. METHODS: We assessed 175 lesions in 175 patients by FFR, IVUS, and 3D-QCA. Correlations between 3D-QCA values, IVUS values, and FFR values were analyzed. Receiver operating characteristic (ROC) curves were used to evaluate diagnostic accuracy of 3D-QCA for predicting FFR <0.8 and to determine the appropriate cut-off value. RESULTS: Upon evaluating 3D-QCA values, minimum lumen area (MLA) correlated with FFR value (r=0.48, P<0.001). Considering IVUS values, MLA correlated with FFR value (r=0.43, P<0.001). Also, 3D-QCA MLA was well correlated with IVUS MLA (r=0.61, P<0.001). The area under the ROC curve (AUC) for 3D-QCA MLA was 0.77, and the best cut-off value was 2.37 (sensitivity: 73%, specificity: 71%). The AUC for IVUS MLA was 0.73, and the best cut-off value was 3.01 (sensitivity: 71%, specificity: 65%). There was no significant difference in AUC for 3D-MLA and IVUS-MLA (P=0.27). CONCLUSIONS: 3D-QCA is not inferior to IVUS for functional assessment of intermediate coronary lesions. We can consider 3D-QCA as a suitable substitute for IVUS or FFR in determining coronary intervention.

Occupational radiation exposure in femoral artery approach is higher than radial artery approach during coronary angiography or percutaneous coronary intervention.

Medical radiation exposure is a significant concern for interventional cardiologists (IC). This study was aimed at estimating the radiation exposure of IC operators and assistants in real clinical practice. The radiation exposure of the operator and assistant was evaluated by conducting two types of procedures via coronary angiography (CAG) and percutaneous coronary intervention (PCI) on 1090 patients in 11-cardiovascular centers in Korea. Radiation exposure was measured using an electronic personal dosimeter (EPD). EPD were attached at 3 points on each participant: on the apron on the left anterior chest (A1), under the apron on the sternum (A2), and on the thyroid shield (T). Average radiation exposure (ARE) of operators at A1, A2, and T was 19.219 uSv, 4.398 uSv, and 16.949 uSv during CAG and 68.618 uSv, 15.213 uSv, and 51.197 uSv during PCI, respectively. ARE of assistants at A1, A2, and T was 4.941 uSv, 0.860 uSv, and 5.232 uSv during CAG and 20.517 uSv, 4.455 uSv, and 16.109 uSv during PCI, respectively. AED of operator was 3.4 times greater during PCI than during CAG.

Usefulness of the trans-stent fractional flow reserve gradient for predicting clinical outcomes.

OBJECTIVES: We evaluated the usefulness of a fractional flow reserve (FFR) gradient across the stent (ΔFFRstent ) for long-term clinical outcomes after percutaneous coronary intervention (PCI) with a drug-eluting stent (DES). BACKGROUND: The clinical meaning of a trans-stent pressure gradient after DES implantation has not been estimated adequately. METHODS: FFR pull-back and intravascular ultrasound (IVUS) were performed after successful PCI in 135 left anterior descending artery lesions. ΔFFRstent was defined as the FFR gradient across the stent. The ΔFFRstent/length was defined as the ΔFFRstent value divided by the total stent length multiplied by 10. Major adverse cardiac events (MACEs) were the composite of all-cause death, target vessel-related myocardial infarction, and target lesion revascularization. RESULTS: Despite successful PCI, ΔFFRstent > 0 was observed in 98.5% of cases. ΔFFRstent ≥ 0.04 and ΔFFRstent/length ≥ 0.009 predicted suboptimal stenting defined as final minimal stent area < 5.5 mm2 . During 2,183 ± 898 days, the MACE-free survival rate was significantly lower in patients with ΔFFRstent ≥ 0.04 and ΔFFRstent/length ≥ 0.009 compared to those with lower values (69.6 vs. 93.4%, log-rank p = .031; 72.1 vs. 97.7%, log-rank p = .003, respectively). ΔFFRstent/length ≥ 0.009 (hazard ratio 10.1, p = .032) was an independent predictor of MACE. CONCLUSION: A trans-stent FFR gradient was frequently observed. ΔFFRstent and ΔFFRstent/length are related to long-term outcomes in DES-treated patients.