Durable Polymer Versus Biodegradable Polymer Drug-Eluting Stents After Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome: The HOST-REDUCE-POLYTECH-ACS Trial.

BACKGROUND: Large-scale randomized comparison of drug-eluting stents (DES) based on durable polymer versus biodegradable polymer technology is currently insufficient in patients with acute coronary syndrome (ACS). The present study aimed to prove the noninferiority of the durable polymer DES (DP-DES) compared with the biodegradable polymer DES (BP-DES) in such patients. METHODS: The HOST-REDUCE-POLYTECH-ACS (Harmonizing Optimal Strategy for Treatment of Coronary Artery Diseases-Comparison of Reduction of Prasugrel Dose or Polymer Technology in ACS Patients) trial is an investigator-initiated, randomized, open-label, adjudicator-blinded, multicenter, noninferiority trial comparing the efficacy and safety of DP-DES and BP-DES in patients with ACS. The primary end point was a patient-oriented composite outcome (a composite of all-cause death, nonfatal myocardial infarction, and any repeat revascularization) at 12 months. The key secondary end point was device-oriented composite outcome (a composite of cardiac death, target-vessel myocardial infarction, or target lesion revascularization) at 12 months. RESULTS: A total of 3413 patients were randomized to receive the DP-DES (1713 patients) and BP-DES (1700 patients). At 12 months, patient-oriented composite outcome occurred in 5.2% in the DP-DES group and 6.4% in the BP-DES group (absolute risk difference, -1.2%; Pnoninferiority<0.001). The key secondary end point, device-oriented composite outcome, occurred less frequently in the DP-DES group (DP-DES vs BP-DES, 2.6% vs 3.9%; hazard ratio, 0.67 [95% CI, 0.46-0.98]; P=0.038), mostly because of a reduction in target lesion revascularization. The rate of spontaneous nonfatal myocardial infarction and stent thrombosis were extremely low, with no significant difference between the 2 groups (0.6% versus 0.8%; P=0.513 and 0.1% versus 0.4%; P=0.174, respectively). CONCLUSIONS: In ACS patients receiving percutaneous coronary intervention, DP-DES was noninferior to BP-DES with regard to patient-oriented composite outcomes at 12 months after index percutaneous coronary intervention. Registration: URL: https://wwwclinicaltrials.gov; Unique identifier: NCT02193971.

Automated Detection of Acute Myocardial Infarction Using Asynchronous Electrocardiogram Signals-Preview of Implementing Artificial Intelligence With Multichannel Electrocardiographs Obtained From Smartwatches: Retrospective Study.

BACKGROUND: When using a smartwatch to obtain electrocardiogram (ECG) signals from multiple leads, the device has to be placed on different parts of the body sequentially. The ECG signals measured from different leads are asynchronous. Artificial intelligence (AI) models for asynchronous ECG signals have barely been explored. OBJECTIVE: We aimed to develop an AI model for detecting acute myocardial infarction using asynchronous ECGs and compare its performance with that of the automatic ECG interpretations provided by a commercial ECG analysis software. We sought to evaluate the feasibility of implementing multiple lead-based AI-enabled ECG algorithms on smartwatches. Moreover, we aimed to determine the optimal number of leads for sufficient diagnostic power. METHODS: We extracted ECGs recorded within 24 hours from each visit to the emergency room of Ajou University Medical Center between June 1994 and January 2018 from patients aged 20 years or older. The ECGs were labeled on the basis of whether a diagnostic code corresponding to acute myocardial infarction was entered. We derived asynchronous ECG lead sets from standard 12-lead ECG reports and simulated a situation similar to the sequential recording of ECG leads via smartwatches. We constructed an AI model based on residual networks and self-attention mechanisms by randomly masking each lead channel during the training phase and then testing the model using various targeting lead sets with the remaining lead channels masked. RESULTS: The performance of lead sets with 3 or more leads compared favorably with that of the automatic ECG interpretations provided by a commercial ECG analysis software, with 8.1%-13.9% gain in sensitivity when the specificity was matched. Our results indicate that multiple lead-based AI-enabled ECG algorithms can be implemented on smartwatches. Model performance generally increased as the number of leads increased (12-lead sets: area under the receiver operating characteristic curve [AUROC] 0.880; 4-lead sets: AUROC 0.858, SD 0.008; 3-lead sets: AUROC 0.845, SD 0.011; 2-lead sets: AUROC 0.813, SD 0.018; single-lead sets: AUROC 0.768, SD 0.001). Considering the short amount of time needed to measure additional leads, measuring at least 3 leads-ideally more than 4 leads-is necessary for minimizing the risk of failing to detect acute myocardial infarction occurring in a certain spatial location or direction. CONCLUSIONS: By developing an AI model for detecting acute myocardial infarction with asynchronous ECG lead sets, we demonstrated the feasibility of multiple lead-based AI-enabled ECG algorithms on smartwatches for automated diagnosis of cardiac disorders. We also demonstrated the necessity of measuring at least 3 leads for accurate detection. Our results can be used as reference for the development of other AI models using sequentially measured asynchronous ECG leads via smartwatches for detecting various cardiac disorders.

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.

Feasibility and evaluation of a large-scale external validation approach for patient-level prediction in an international data network: validation of models predicting stroke in female patients newly diagnosed with atrial fibrillation.

BACKGROUND: To demonstrate how the Observational Healthcare Data Science and Informatics (OHDSI) collaborative network and standardization can be utilized to scale-up external validation of patient-level prediction models by enabling validation across a large number of heterogeneous observational healthcare datasets. METHODS: Five previously published prognostic models (ATRIA, CHADS2, CHADS2VASC, Q-Stroke and Framingham) that predict future risk of stroke in patients with atrial fibrillation were replicated using the OHDSI frameworks. A network study was run that enabled the five models to be externally validated across nine observational healthcare datasets spanning three countries and five independent sites. RESULTS: The five existing models were able to be integrated into the OHDSI framework for patient-level prediction and they obtained mean c-statistics ranging between 0.57-0.63 across the 6 databases with sufficient data to predict stroke within 1 year of initial atrial fibrillation diagnosis for females with atrial fibrillation. This was comparable with existing validation studies. The validation network study was run across nine datasets within 60 days once the models were replicated. An R package for the study was published at https://github.com/OHDSI/StudyProtocolSandbox/tree/master/ExistingStrokeRiskExternalValidation. CONCLUSION: This study demonstrates the ability to scale up external validation of patient-level prediction models using a collaboration of researchers and a data standardization that enable models to be readily shared across data sites. External validation is necessary to understand the transportability or reproducibility of a prediction model, but without collaborative approaches it can take three or more years for a model to be validated by one independent researcher. In this paper we show it is possible to both scale-up and speed-up external validation by showing how validation can be done across multiple databases in less than 2 months. We recommend that researchers developing new prediction models use the OHDSI network to externally validate their models.

Impact of new-onset diabetes on clinical outcomes after ST segment-elevated myocardial infarction.

Objective. Patients with diabetes have higher mortality rate than patients without diabetes after ST-segment elevated myocardial infarction (STEMI). Prognosis of patients with new onset diabetes (NOD) after STEMI remains unclear. The aim of this study was to evaluate the prognosis of patients with NOD compared to that of patients without NOD after STEMI. Design. This study was a retrospective observational study. We enrolled 901 STEMI patients. Patients were divided into diabetic and non-diabetic groups at index admission. Non-diabetic group was divided into NOD and non-NOD groups. Kaplan-Meier analysis and Cox's proportional hazard regression models were used to compare major adverse cardiac events (MACE) free survival rate and hazard ratio for MACE between NOD and non-NOD groups. Results. Mean follow-up period was 59 ± 28 months. Diabetes group had higher MACE than non-diabetes group (p = .038). However, MACE was not different between NOD and non-NOD groups (p = 1.000). After 1:2 propensity score matching, incidence of MACE was not different between the two groups. In Kaplan-Meier survival curves, MACE-free survival rates were not statistically different between NOD and non-NOD groups either (p = .244). Adjusted hazard ratios of NOD for MACE, all-cause of death, recurrent myocardial infarction, and target vessel revascularization were 0.697 (95% confidence interval [CI]: 0.362-1.345, p = .282), 0.625 (95% CI: 0.179-2.183, p = .461), 0.794 (95% CI: 0.223-2.835, p = .723), and 0.506 (95% CI: 0.196-1.303, p = .158), respectively. Conclusion. This retrospective observational study with a limited statistical power did not show a different prognosis in patients with and without NOD.

Myocardial Mass Contributes to the Discrepancy Between Anatomic Stenosis Severity Assessed by Intravascular Ultrasound and Fractional Flow Reserve in Intermediate Lesions of the Coronary Artery.

OBJECTIVES: The present study investigated the major contributors to the discrepancy between the minimal lumen area (MLA) and fractional flow reserve (FFR). BACKGROUND: There was considerable discrepancy between MLA or diameter stenosis (DS) and FFR. METHODS: We enrolled 744 patients with intermediate stenoses of the left anterior descending artery (LAD). Summed epicardial coronary artery length distal to the target stenosis was obtained from each longest view of the vessels on the coronary angiograms. Mismatching was defined as a lesion with FFR of >0.80 and MLA smaller than the best cut-off value (BCV) for predicting FFR of ≤0.80. Reverse mismatching was defined as a lesion with FFR of ≤0.80 and MLA larger than the BCV. RESULTS: Summed epicardial coronary artery length was longer at the lesions of proximal LAD than that of middle LAD (380 mm ± 82 mm vs. 341 mm ± 80 mm, P < 0.001). Reverse mismatching was found more frequently in the proximal than middle LAD (28.3% vs. 5.5%, P < 0.001). Independent predictors of FFR ≤ 0.80 were age, male, multi-vessel disease, proximal LAD lesion, MLA, DS, plaque burden at distal reference, lesion length and summed epicardial coronary artery length. Proximal LAD lesion was an independent predictor of reverse mismatching (hazard ratio 3.162, 1.858-5.382, P < 0.001). CONCLUSIONS: Myocardial mass subtended by a lesion is an important factor predicting FFR ≤0.80 and discrepancy between FFR and MLA. Myocardial mass subtended by a lesion should be considered when determining the revascularization therapy by intravascular ultrasound parameters. © 2017 Wiley Periodicals, Inc.

Invasive Assessment of Coronary Physiology Predicts Late Mortality After Heart Transplantation.

BACKGROUND: The aim of this study is to determine the prognostic value of invasively assessing coronary physiology early after heart transplantation. METHODS AND RESULTS: Seventy-four cardiac transplant recipients had fractional flow reserve, coronary flow reserve, index of microcirculatory resistance (IMR), and intravascular ultrasound performed down the left anterior descending coronary artery soon after (baseline) and 1 year after heart transplantation. The primary end point was the cumulative survival free of death or retransplantation at a mean follow-up of 4.5±3.5 years. The cumulative event-free survival was significantly lower in patients with a fractional flow reserve <0.90 at baseline (42% versus 79%; P=0.01) or an IMR ≥20 measured 1 year after heart transplantation (39% versus 69%; P=0.03). Patients in whom IMR decreased or did not change from baseline to 1 year had higher event-free survival compared with patients with an increase in IMR (66% versus 36%; P=0.03). Fractional flow reserve <0.90 at baseline (hazard ratio, 0.13; 95% confidence interval, 0.02-0.81; P=0.03), IMR ≥20 at 1 year (hazard ratio, 3.93; 95% confidence interval, 1.08-14.27; P=0.04), and rejection during the first year (hazard ratio, 6.00; 95% confidence interval, 1.56-23.09; P=0.009) were independent predictors of death/retransplantation, whereas intravascular ultrasound parameters were not. CONCLUSIONS: Invasive measures of coronary physiology (fractional flow reserve and IMR) determined early after heart transplantation are significant predictors of late death or retransplantation.

Diabetic retinopathy is associated with diastolic dysfunction in type 2 diabetic patients with non-ischemic dilated cardiomyopathy.

BACKGROUND: To investigate the association between diabetic retinopathy (DR) and myocardial dysfunction in patients with type 2 diabetes and dilated cardiomyopathy (dCMP). METHODS: Data were collected retrospectively from 89 patients with dCMP (46 with type 2 diabetes and 43 without diabetes) and no evidence of coronary artery disease. Echocardiographic parameters and laboratory data, including lipid profiles and fundus findings, were obtained from medical records. A left ventricular ejection fraction (LVEF) less than 40% was considered impaired systolic function, while an E/E' ratio greater than 15 was considered elevated left ventricular (LV) filling pressure. RESULTS: Baseline characteristics show that LVEF was not significantly different between patients with and without diabetes or between diabetic patients with and without DR. Among the diastolic function parameters, patients with DR exhibited higher E/E' ratios (left ventricular filling pressures) than patients without DR (23.75 ± 13.37 vs 11.71 ± 3.50, P = 0.022). Logistic regression analysis revealed that statin use lowered the risk of impaired systolic dysfunction in all patients (odds ratio (OR) 0.33, 95% confidence interval (CI) 0.12-0.92, P = 0.034) and in patients with diabetes (OR 0.273, 95% CI 0.08-0.99, P = 0.049), while the presence of DR was associated with a higher risk of elevated LV filling filling pressure in patients with diabetes (OR 18.00, 95% CI 1.50-216.62, P = 0.023). CONCLUSIONS: In conclusion, DR was associated with elevated LV filling pressure in patients with dCMP. DR may not only represent microvascular long-term complications in patients with diabetes but may also be associated with more advanced form of diastolic dysfunction among diabetic patients with cardiomyopathy.

Invasive evaluation of patients with angina in the absence of obstructive coronary artery disease.

BACKGROUND: More than 20% of patients presenting to the cardiac catheterization laboratory with angina have no angiographic evidence of coronary artery disease. Despite a "normal" angiogram, these patients often have persistent symptoms, recurrent hospitalizations, a poor functional status, and adverse cardiovascular outcomes, without a clear diagnosis. METHODS AND RESULTS: In 139 patients with angina in the absence of obstructive coronary artery disease (no diameter stenosis >50%), endothelial function was assessed; the index of microcirculatory resistance, coronary flow reserve, and fractional flow reserve were measured; and intravascular ultrasound was performed. There were no complications. The average age was 54.0±11.4 years, and 107 (77%) were women. All patients had at least some evidence of atherosclerosis based on an intravascular ultrasound examination of the left anterior descending artery. Endothelial dysfunction (a decrease in luminal diameter of >20% after intracoronary acetylcholine) was present in 61 patients (44%). Microvascular impairment (an index of microcirculatory resistance ≥25) was present in 29 patients (21%). Seven patients (5%) had a fractional flow reserve ≤0.80. A myocardial bridge was present in 70 patients (58%). Overall, only 32 patients (23%) had no coronary explanation for their angina, with normal endothelial function, normal coronary physiological assessment, and no myocardial bridging. CONCLUSIONS: The majority of patients with angina in the absence of obstructive coronary artery disease have occult coronary abnormalities. A comprehensive invasive assessment of these patients at the time of coronary angiography can be performed safely and provides important diagnostic information that may affect treatment and outcomes.

Impact of Age on the Functional Significance of Intermediate Epicardial Artery Disease.

BACKGROUND: The functional significance of an intermediate coronary lesion is crucial for determining the treatment strategy, but age-related changes in cardiovascular function could affect the functional significance of an epicardial stenosis. The aim of this study was therefore to investigate the impact of age on fractional flow reserve (FFR) measurements in patients with intermediate coronary artery disease (CAD). METHODS AND RESULTS: Intracoronary pressure measurements and intravascular ultrasound (IVUS) were performed in 178 left anterior descending coronary arteries with intermediate stenosis. The morphological characteristics and FFR of 91 lesions in patients <65 years old were compared with those of 87 patients ≥65 years old. There was no difference in lesion location, diameter stenosis, minimum lumen area, plaque burden, or lesion length between the 2 age groups. Elderly patients had higher FFR (0.81±0.06 vs. 0.79±0.06, P=0.004) and lower ∆FFR, defined as the difference between resting Pd/Pa and FFR (0.13±0.05 vs. 0.15±0.05, P=0.014). Age, along with the location and degree of stenosis, was independently associated with FFR and ∆FFR (ß=0.162, P=0.008; ß=-0.131, P=0.043, respectively). CONCLUSIONS: Elderly patients with intermediate CAD are more likely to have higher FFR and lower ∆FFR, despite a similar degree of epicardial stenosis, compared with younger patients. (Circ J 2016; 80: 1583-1589).

Clinical Outcomes in Patients with Deferred Coronary Lesions according to Disease Severity Assessed by Fractional Flow Reserve.

Data on the clinical outcomes in deferred coronary lesions according to functional severity have been limited. This study evaluated the clinical outcomes of deferred lesions according to fractional flow reserve (FFR) grade using Korean FFR registry data. Among 1,294 patients and 1,628 lesions in Korean FFR registry, 665 patients with 781 deferred lesions were included in this study. All participants were consecutively categorized into 4 groups according to FFR; group 1: ≥ 0.96 (n = 56), group 2: 0.86-0.95 (n = 330), group 3: 0.81-0.85 (n = 170), and group 4: ≤ 0.80 (n = 99). Primary endpoint was major adverse cardiac events (MACE), a composite of all-cause death, myocardial infarction, and target vessel revascularization. The median follow-up period was 2.1 years. During follow-up, the incidence of MACE in groups 1-4 was 1.8%, 7.6%, 8.8%, and 13.1%, respectively. Compared to group 1, the cumulative rate by Kaplan-Meier analysis of MACE was not different for groups 2 and 3. However, group 4 had higher cumulative rate of MACE compared to group 1 (log-rank P = 0.013). In the multivariate Cox hazard models, only FFR (hazard ratio [HR], 0.95; P = 0.005) was independently associated with MACE among all participants. In contrast, previous history of percutaneous coronary intervention (HR, 2.37; P = 0.023) and diagnosis of acute coronary syndrome (ACS) (HR, 2.35; P = 0.015), but not FFR, were independent predictors for MACE in subjects with non-ischemic (FFR ≥ 0.81) deferred coronary lesions. Compared to subjects with ischemic deferred lesions, clinical outcomes in subjects with non-ischemic deferred lesions according to functional severity are favorable. However, longer-term follow-up may be necessary.

ß-Blocker Therapy in the Era of Primary Percutaneous Intervention for ST Elevation Myocardial Infarction.

OBJECTIVES: With the present therapeutic advances in the era of primary percutaneous coronary intervention (PCI), the role of ß-blockers in ST elevation acute myocardial infarction (STEMI) has remained contentious. METHODS: We analyzed the data and clinical outcomes of 901 STEMI patients who had undergone primary PCI. We classified the patients into ß-blocker (n = 598) and non-ß-blocker groups (n = 303). RESULTS: The cumulative incidence of all-cause death was 10.0% in the ß-blocker group and 25.4% in the non-ß-blocker group (p < 0.001). The incidence of major adverse cardiac events (MACE) was 22.1% in the ß-blocker group and 34.3% in the non-ß-blocker group (p < 0.001). The relative hazard ratio (HR) of ß-blockers for all-cause death and MACE with low left ventricle ejection fraction (LVEF; <50%) was 0.55 [95% confidence interval (CI) 0.35-0.86, p = 0.009] and 0.75 (95% CI 0.51-1.09, p = 0.125), respectively. In patients with normal LVEF (≥50%), the relative HR of ß-blockers for death and MACE were 0.50 (95% CI 0.29-0.88, p = 0.016) and 0.75 (95% CI 0.51-1.12, p = 0.162), respectively. After propensity score matching of the difference of the baseline characteristics, the Kaplan-Meier survival curve demonstrated lower mortality in the ß-blocker group than in the non-ß-blocker group with both low LVEF and normal LVEF (p = 0.02 and p = 0.001, respectively). CONCLUSIONS: ß-Blockers have beneficial clinical outcomes in the era of primary PCI for STEMI, regardless of the LVEF. © 2015 S. Karger AG, Basel.

Independent risk factors for mortality in patients with chronic obstructive pulmonary disease who undergo comprehensive cardiac evaluations.

BACKGROUND: Cardiovascular disease is the most common cause of death in chronic obstructive pulmonary disease (COPD). However, the impact of cardiovascular comorbidities on the prognosis of COPD is not well known. OBJECTIVES: This study was performed to investigate the effects of cardiovascular comorbidities on the prognosis of COPD. METHODS: We enlisted 229 patients with COPD who underwent comprehensive cardiac evaluations including coronary angiography and echocardiography at Ajou University Hospital between January 2000 and December 2012. Survival analyses were performed in this retrospective cohort. RESULTS: Kaplan-Meier analyses showed that COPD patients without left heart failure (mean survival = 12.5 ± 0.7 years) survived longer than COPD patients with left heart failure (mean survival = 6.7 ± 1.4 years; p = 0.003), and the survival period of nonanemic COPD patients (mean survival = 13.8 ± 0.8 years) was longer than that of anemic COPD patients (mean survival = 8.3 ± 0.8 years; p < 0.001). The survival period in COPD with coronary artery disease (CAD; mean survival = 11.37 ± 0.64 years) was not different from that in COPD without CAD (mean survival = 11.98 ± 0.98 years; p = 0.703). According to a multivariate Cox regression model, a lower hemoglobin level, a lower left ventricular ejection fraction, and the forced expiratory volume in 1 s (FEV1) were independently associated with higher mortality in the total COPD group (p < 0.05). CONCLUSIONS: Hemoglobin levels and left ventricular ejection fraction along with a lower FEV1 were identified as independent risk factors for mortality in COPD patients who underwent comprehensive cardiac evaluations, suggesting that multidisciplinary approaches are required in the care of COPD.

Relationship between intravascular ultrasound parameters and fractional flow reserve in intermediate coronary artery stenosis of left anterior descending artery: intravascular ultrasound volumetric analysis.

OBJECTIVES: The objective of this study was to assess the relationship between intravascular ultrasound (IVUS) parameters, including volumetric analysis, and fractional flow reserve (FFR). BACKGROUND: Although it is known that coronary atherosclerosis burden measured by IVUS volumetric analysis is related with clinical outcomes, its relationship with functional significance remains unknown. METHODS: Both IVUS and FFR were performed in 206 cases of intermediate stenosis of the left anterior descending artery (LAD). Myocardial ischemia was assessed by FFR and maximal hyperemia was induced by continuous intracoronary adenosine infusion. FFR < 0.80 was considered as significant inducible myocardial ischemia. We performed standard IVUS parameter measurements and volumetric analyses. IVUS parameter comparison was performed in the presence (n = 90) or absence (n =116) of significant myocardial ischemia. RESULTS: Lesions with minimal lumen area (MLA) ≥ 4.0 mm2 had FFR ≥ 0.80 in 91.4% of cases, while 50.9% of lesions with MLA < 4.0 mm2 had FFR < 0.80. The independent predictors of FFR < 0.80 were IVUS lesion length (odds ratio [OR]: 1.1, 95% confidence interval [CI] = 1.06­1.18, P < 0.001) and MLA significance according to the lesion location (OR: 7.01, 95% CI = 3.09­15.92, P = 0.001). FFR correlated with plaque volume (r = −0.345, P < 0.001) and percent atheroma volume (PAV) (r = −0.398, P < 0.001). Lesions with significant ischemia (FFR < 0.80) as compared to those with FFR > 0.80 were associated with larger plaque volume (181.8 ± 82.3 vs. 125.9 ± 77.9 mm3, P < 0.001) and PAV (58.9 ± 5.6 vs. 53.8 ± 7.9%, P < 0.001). CONCLUSIONS: IVUS parameters representing severity and extent of atheromatous plaque correlated with functional significance in LAD lesions with intermediate stenosis.

Finite Element Analysis of a Rib Cage Model: Influence of Four Variables on Fatigue Life during Simulated Manual CPR.

Cardiopulmonary resuscitation (CPR) is a life-saving technique used in emergencies when the heart stops beating, typically involving chest compressions and ventilation. Current adult CPR guidelines do not differentiate based on age beyond infancy and childhood. This oversight increases the risk of fatigue fractures in the elderly due to decreased bone density and changes in thoracic structure. Therefore, this study aimed to investigate the correlation and impact of factors influencing rib fatigue fractures for safer out-of-hospital manual cardiopulmonary resuscitation (OHMCPR) application. Using the finite element analysis (FEA) method, we performed fatigue analysis on rib cage models incorporating chest compression conditions and age-specific trabecular bone properties. Fatigue life analyses were conducted on three age-specific rib cage models, each differentiated by trabecular bone properties, to determine the influence of four explanatory variables (the properties of the trabecular bone (a surrogate for the age of the subject), the site of application of the compression force on the breastbone, the magnitude of applied compression force, and the rate of application of the compression force) on the fatigue life of the model. Additionally, considering the complex interaction of chest compression conditions during actual CPR, we aimed to predict rib fatigue fractures under conditions simulating real-life scenarios by analyzing the sensitivity and interrelation of chest compression conditions on the model's fatigue life. Time constraints led to the selection of optimal analysis conditions through the use of design of experiments (DOE), specifically orthogonal array testing, followed by the construction of a deep learning-based metamodel. The predicted fatigue life values of the rib cage model, obtained from the metamodel, showed the influence of the four explanatory variables on fatigue life. These results may be used to devise safer CPR guidelines, particularly for the elderly at a high risk of acute cardiac arrest, safeguarding against potential complications like fatigue fractures.

Differential Impact of Fractional Flow Reserve Measured After Coronary Stent Implantation by Left Ventricular Dysfunction.

Background: Both left ventricular systolic function and fractional flow reserve (FFR) are prognostic factors after percutaneous coronary intervention (PCI). However, how these prognostic factors are inter-related in risk stratification of patients after PCI remains unclarified. Objectives: This study evaluated differential prognostic implication of post-PCI FFR according to left ventricular ejection fraction (LVEF). Methods: A total of 2,965 patients with available LVEF were selected from the POST-PCI FLOW (Prognostic Implications of Physiologic Investigation After Revascularization with Stent) international registry of patients with post-PCI FFR measurement. The primary outcome was a composite of cardiac death or target-vessel myocardial infarction (TVMI) at 2 years. The secondary outcome was target-vessel revascularization (TVR) and target vessel failure, which was a composite of cardiac death, TVMI, or TVR. Results: Post-PCI FFR was independently associated with the risk of target vessel failure (per 0.01 decrease: HRadj: 1.029; 95% CI: 1.009-1.049; P = 0.005). Post-PCI FFR was associated with increased risk of cardiac death or TVMI (HRadj: 1.145; 95% CI: 1.025-1.280; P = 0.017) among patients with LVEF ≤40%, and with that of TVR in patients with LVEF >40% (HRadj: 1.028; 95% CI: 1.005-1.052; P = 0.020). Post-PCI FFR ≤0.80 was associated with increased risk of cardiac death or TVMI in the LVEF ≤40% group and with that of TVR in LVEF >40% group. Prognostic impact of post-PCI FFR for the primary outcome was significantly different according to LVEF (Pinteraction = 0.019). Conclusions: Post-PCI FFR had differential prognostic impact according to LVEF. Residual ischemia by post-PCI FFR ≤0.80 was a prognostic indicator for cardiac death or TVMI among patients with patients with LVEF ≤40%, and it was associated with TVR among patients with patients with LVEF>40%. (Prognostic Implications of Physiologic Investigation After Revascularization with Stent [POST-PCI FLOW]; NCT04684043).

Noncoronary ST elevation and polymorphic ventricular tachycardia during left-sided accessory pathway ablation.

INTRODUCTION: An early repolarization (ER) pattern on electrocardiogram (ECG) sometimes has the risk of polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF). An abnormal ER pattern can develop in various experimental or clinical situations. We experienced 4 cases of abnormal ER pattern with or without PVT during the radiofrequency (RF) ablation of the left accessory pathway. METHODS AND RESULTS: An electrophysiologic study and RF ablation were performed in 4 patients. Four patients had atrioventricular reentrant tachycardia. During RF ablation of the left accessory pathway, severe chest pain developed and was followed by abnormal J-point elevation. During the ongoing chest pain and J-point elevation, coronary angiograms showed normal findings. The chest pain and J-point elevation were followed by PVT or VF that was unresponsive to defibrillation. The PVT was spontaneously terminated and repeated. After 0.5 mg atropin was given, chest pain and ECG change disappeared. CONCLUSION: The mechanisms of ER syndrome during RF ablation might be increased vagal tone due to chest pain or direct vagal stimulation.

Comparison of 3-year clinical outcomes between classic crush and modified mini-crush technique in coronary bifurcation lesions.

OBJECTIVES: We aimed to compare long-term clinical outcomes between modified mini-crush (modi-MC) technique with classic crush (crush) technique for treatment of bifurcation lesions. BACKGROUND: The modi-MC technique showed excellent procedural success and favorable 9-month clinical outcomes. METHODS: From January 2005 to November 2009, we enrolled patients with de novo bifurcation lesions treated with modi-MC (n = 112 lesions in 111 patients) and crush technique (n = 69 lesions in 67 patients). Primary endpoint was rate of major adverse cardiac events (MACE), a composite of all-cause death, myocardial infarction (MI), and target lesion revascularization (TLR) at 3 years. RESULTS: There was no significant difference in baseline characteristics. The modi-MC technique showed a significantly higher success rate of final kissing balloon inflation (84.1 vs. 98.2%, P = 0.001). After 3 years, MACE rate was significantly lower in the modi-MC group (25.4 vs. 12.6%, P = 0.030). The incidence of all-cause death was 7.5 vs. 2.7% (P = 0.087), MI was 4.5 vs. 1.8% (P = 0.290), TLR was 17.4 vs. 8.9% (P = 0.093) and stent thrombosis was 3.0 vs. 1.8% (P = 0.632) in the crush and modi-MC groups, respectively. CONCLUSIONS: The modified mini-crush technique showed more favorable 3-year clinical outcomes compared to the classic crush technique.

Evaluation of rosuvastatin-induced QT prolongation risk using real-world data, in vitro cardiomyocyte studies, and mortality assessment.

Drug-induced QT prolongation is attributed to several mechanisms, including hERG channel blockage. However, the risks, mechanisms, and the effects of rosuvastatin-induced QT prolongation remain unclear. Therefore, this study assessed the risk of rosuvastatin-induced QT prolongation using (1) real-world data with two different settings, namely case-control and retrospective cohort study designs; (2) laboratory experiments using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM); (3) nationwide claim data for mortality risk evaluation. Real-world data showed an association between QT prolongation and the use of rosuvastatin (OR [95% CI], 1.30 [1.21-1.39]) but not for atorvastatin (OR [95% CI], 0.98 [0.89-1.07]). Rosuvastatin also affected the sodium and calcium channel activities of cardiomyocytes in vitro. However, rosuvastatin exposure was not associated with a high risk of all-cause mortality (HR [95% CI], 0.95 [0.89-1.01]). Overall, these results suggest that rosuvastatin use increased the risk of QT prolongation in real-world settings, significantly affecting the action potential of hiPSC-CMs in laboratory settings. Long-term rosuvastatin treatment was not associated with mortality. In conclusion, while our study links rosuvastatin use to potential QT prolongation and possible influence on the action potential of hiPSC-CMs, long-term use does not show increased mortality, necessitating further research for conclusive real-world applications.

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.