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.

Comparison of Antiplatelet Monotherapies After Percutaneous Coronary Intervention According to Clinical, Ischemic, and Bleeding Risks.

BACKGROUND: Clopidogrel was superior to aspirin monotherapy in secondary prevention after percutaneous coronary intervention (PCI). OBJECTIVES: The purpose of this study was to evaluate the benefits of clopidogrel across high-risk subgroups METHODS: This was a post hoc analysis of the HOST-EXAM (Harmonizing Optimal Strategy for Treatment of coronary artery diseases-EXtended Antiplatelet Monotherapy) trial that randomly assigned patients who were event free for 6 to 18 months post-PCI on dual antiplatelet therapy (DAPT) to clopidogrel or aspirin monotherapy. Two clinical risk scores were used for risk stratification: the DAPT score and the Thrombolysis In Myocardial Infarction Risk Score for Secondary Prevention (TRS 2°P) (the sum of age ≥75 years, diabetes, hypertension, current smoking, peripheral artery disease, stroke, coronary artery bypass grafting, heart failure, and renal dysfunction). The primary composite endpoint was a composite of all-cause death, nonfatal myocardial infarction, stroke, readmission because of acute coronary syndrome, and major bleeding (Bleeding Academic Research Consortium type ≥3) at 2 years after randomization. RESULTS: Among 5,403 patients, clopidogrel monotherapy showed a lower rate of the primary composite endpoint than aspirin monotherapy (HR: 0.73; 95% CI: 0.59-0.90). The benefit of clopidogrel over aspirin was consistent regardless of TRS 2°P (high TRS 2°P [≥3] group: HR: 0.65 [95% CI: 0.44-0.96]; and low TRS 2°P [<3] group: HR: 0.77 [95% CI: 0.60-0.99]) (P for interaction = 0.454) and regardless of DAPT score (high DAPT score [≥2] group: HR: 0.68 [95% CI: 0.46-1.00]; and low DAPT score [<2] group: HR: 0.75 [95% CI: 0.59-0.96]) (P for interaction = 0.662). The association was similar for the individual outcomes. CONCLUSIONS: The beneficial effect of clopidogrel over aspirin monotherapy was consistent regardless of clinical risk or relative ischemic and bleeding risks compared with aspirin monotherapy. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis- EXtended Antiplatelet Monotherapy [HOST-EXAM]; NCT02044250).

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

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

Impact of treatment adherence on the effectiveness and safety of oral anticoagulants in patients with atrial fibrillation: a retrospective cohort study.

AIMS: The impact of adherence to oral anticoagulation has not been reported in terms of absolute risk, which would enhance patients' understanding and treatment adherence. METHODS AND RESULTS: This retrospective cohort study analysed data from the National Health Insurance Database of Korea, from January 2010 to December 2018, on 84 227 patients with non-valvular atrial fibrillation (NVAF). The participants were analysed according to their overall adherence to oral anticoagulants (OACs) and further divided into four groups: non-vitamin K antagonist oral anticoagulant (NOAC) adherent, vitamin K antagonist (VKA) adherent, NOAC non-adherent, and VKA non-adherent. The incidence of ischaemic stroke, major bleeding, and death was compared between the four groups using risk difference, number needed to treat and number needed to harm. Among the participants, 50 178 were adherent to (OACs), while 34 049 were non-adherent. The incidence of major bleeding was higher in the adherent group (4.49%; 95% confidence interval, 4.11-4.85%) than in the non-adherent group (3.61%; 3.16-4.06%), and the incidence of ischaemic stroke was higher in the non-adherent group (7.68%; 7.08-8.33%) than in the adherent group (5.61%; 5.17-6.07%). In terms of risk difference, adherence to OACs increased the risk of major bleeding by 0.87% and decreased the risk of ischaemic stroke by 2.08%. This finding suggests that one additional major bleeding event occurred for every 115 adherent patients, and one additional ischaemic stroke event was prevented for every 48 adherent patients. CONCLUSION: The benefits of OAC adherence in NVAF patients for ischaemic stroke prevention exceeding the risk of bleeding are shown more clearly in terms of absolute risk.

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

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

Comparison of Factors Associated With Direct Versus Transferred-in Admission to Government-Designated Regional Centers Between Acute Ischemic Stroke and Myocardial Infarction in Korea.

BACKGROUND: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. METHODS: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. RESULTS: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI; additionally, age (65-74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. CONCLUSIONS: Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

A Multicenter, Randomized, Double-blind, Active-controlled, Factorial Design, Phase III Clinical Trial to Evaluate the Efficacy and Safety of Combination Therapy of Pitavastatin and Ezetimibe Versus Monotherapy of Pitavastatin in Patients With Primary Hypercholesterolemia.

PURPOSE: Pitavastatin is a unique lipophilic statin with moderate efficacy in lowering LDL-C levels by 30% to 50% with a tolerable safety profile. However, the efficacy of adding ezetimibe to pitavastatin in patients with dyslipidemia has not been well investigated. Therefore, the objective of this double-blind, multicenter, randomized, Phase III study was to compare the efficacy and safety of pitavastatin and ezetimibe combination therapy with those of pitavastatin monotherapy in Korean patients with primary hypercholesterolemia. METHODS: Korean men and women aged >19 and <80 years with primary hypercholesterolemia requiring medical treatment were included in this study. During the 8-week screening period, all patients were instructed to make therapeutic lifestyle changes. The screening period consisted of a 4-week washout period and a placebo run-in period (4-8 weeks). During treatment period I, patients were randomly assigned to receive 1 of 4 treatments: pitavastatin 2 mg plus ezetimibe 10 mg, pitavastatin 2 mg, pitavastatin 4 mg plus ezetimibe 10 mg, or pitavastatin 4 mg. The 8-week double-blind treatment period then commenced. Adverse events (AEs), clinical laboratory data, and vital signs were assessed in all patients. FINDINGS: The percentages in LDL-C from baseline after 8 weeks of double-blind treatment decreased significantly in the pooled pitavastatin/ezetimibe (-52.8% [11.2%]) and pooled pitavastatin (-37.1% [14.1%]) groups. Treatment with pitavastatin/ezetimibe resulted in a significantly greater LDL-C-lowering effect than that with pitavastatin (difference, -15.8 mg/dL; 95% CI, -18.7 to -12.9; P < 0.001). The precentages of achieving LDL-C goal in pooled pitavastatin/ezetimibe and pooled pitavastatin groups were 94.2% and 69.1%, respectively (P < 0.001). There were no significant differences in the incidence of overall AEs and adverse drug reactions. Serious AEs were comparable between the groups. IMPLICATIONS: Pitavastatin and ezetimibe combinations effectively and safely decreased LDL-C levels by >50% in patients with dyslipidemia. The safety and tolerability of pitavastatin and ezetimibe combination therapy were comparable with those of pitavastatin monotherapy. CLINICALTRIALS: gov identifier: NCT04584736.

Impact of right atrial enlargement on clinical outcome in patients with atrial fibrillation.

Background: Left atrial (LA) remodeling is associated with adverse cardiovascular events, including heart failure (HF) and stroke in patients with atrial fibrillation (AF). However, there are limited data on the value of right atrial (RA) remodeling in this population. We investigated the prognostic role of RA enlargement in patients with non-valvular AF. Methods and results: We analyzed 254 consecutive patients (age = 69 ± 12years, male:female = 165:89, mean left ventricular ejection fraction = 58.0 ± 7.2%) with non-valvular AF who underwent two-dimensional echocardiography from a single center. RA and LA volumes were measured from apical views and indexed to the body surface areas (right atrial volume index [RAVI] and left atrial volume index [LAVI]) and RAVI > 30mL/m2 and LAVI > 34mL/m2 were considered as enlarged. The relationship between RA enlargement and composite clinical outcome of hospitalization for HF (HHF), stroke, systemic embolism, or death from any cause was assessed. Right atrial (RA) enlargement was associated with older age and more frequent prevalence of persistent or permanent AF. During a median follow-up of 47.1 months, 77 patients (30%) had experienced primary composite outcome. In a multivariable model, RA enlargement, but not LA enlargement, was independently associated with adverse clinical outcomes even after adjusting for clinical and echocardiographic factors {adjusted hazard ratio [HR], 1.90 [95% confidence interval (CI), 1.14-3.18], p = 0.014 for primary composite outcome; adjusted HR, 2.70 [95% CI, 1.27-5.67], p = 0.001 for HHF or all cause death}. Conclusion: RA enlargement was independently associated with an increased risk of HF, stroke, systemic embolization or death in patients with non-valvular AF, suggesting that RA volume can be helpful in assessing future cardiovascular risk in this population.

The Clinical Impact of ß-Blocker Therapy on Patients With Chronic Coronary Artery Disease After Percutaneous Coronary Intervention.

BACKGROUND AND OBJECTIVES: The outcome benefits of ß-blockers in chronic coronary artery disease (CAD) have not been fully assessed. We evaluated the prognostic impact of ß-blockers on patients with chronic CAD after percutaneous coronary intervention (PCI). METHODS: A total of 3,075 patients with chronic CAD were included from the Grand Drug-Eluting Stent registry. We analyzed ß-blocker prescriptions, including doses and types, in each patient at 3-month intervals from discharge. After propensity score matching, 1,170 pairs of patients (ß-blockers vs. no ß-blockers) were derived. Primary outcome was defined as a composite endpoint of all-cause death and myocardial infarction (MI). We further analyzed the outcome benefits of different doses (low-, medium-, and high-dose) and types (conventional or vasodilating) of ß-blockers. RESULTS: During a median (interquartile range) follow-up of 3.1 (3.0-3.1) years, 134 (5.7%) patients experienced primary outcome. Overall, ß-blockers demonstrated no significant benefit in primary outcome (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.63-1.24), all-cause death (HR, 0.87; 95% CI, 0.60-1.25), and MI (HR, 1.25; 95% CI, 0.49-3.15). In subgroup analysis, ß-blockers were associated with a lower risk of all-cause death in patients with previous MI and/or revascularization (HR, 0.38; 95% CI, 0.14-0.99) (p for interaction=0.045). No significant associations were found for the clinical outcomes with different doses and types of ß-blockers. CONCLUSIONS: Overall, ß-blocker therapy was not associated with better clinical outcomes in patients with chronic CAD undergoing PCI. Limited mortality benefit of ß-blockers may exist for patients with previous MI and/or revascularization. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03507205.

Comparisons of Prehospital Delay and Related Factors Between Acute Ischemic Stroke and Acute Myocardial Infarction.

Background Prehospital delay is an important contributor to poor outcomes in both acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We aimed to compare the prehospital delay and related factors between AIS and AMI. Methods and Results We identified patients with AIS and AMI who were admitted to the 11 Korean Regional Cardiocerebrovascular Centers via the emergency room between July 2016 and December 2018. Delayed arrival was defined as a prehospital delay of >3 hours, and the generalized linear mixed-effects model was applied to explore the effects of potential predictors on delayed arrival. This study included 17 895 and 8322 patients with AIS and AMI, respectively. The median value of prehospital delay was 6.05 hours in AIS and 3.00 hours in AMI. The use of emergency medical services was the key determinant of delayed arrival in both groups. Previous history, 1-person household, weekday presentation, and interhospital transfer had higher odds of delayed arrival in both groups. Age and sex had no or minimal effects on delayed arrival in AIS; however, age and female sex were associated with higher odds of delayed arrival in AMI. More severe symptoms had lower odds of delayed arrival in AIS, whereas no significant effect was observed in AMI. Off-hour presentation had higher and prehospital awareness had lower odds of delayed arrival; however, the magnitude of their effects differed quantitatively between AIS and AMI. Conclusions The effects of some nonmodifiable and modifiable factors on prehospital delay differed between AIS and AMI. A differentiated strategy might be required to reduce prehospital delay.

Clinical Outcomes in Patients With Delayed Hospitalization for Non-ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Recently, the number of patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI) has reduced, whereas increased mortality was reported. A plausible explanation for increased mortality was prehospital delay because of patients' reticence of their symptoms. OBJECTIVES: The purpose of this study was to investigate the association between prehospital delay and clinical outcomes in patients with NSTEMI METHODS: Among 13,104 patients from the Korea-Acute-Myocardial-Infarction-Registry-National Institutes of Health, the authors evaluated 6,544 patients with NSTEMI. Study patients were categorized into 2 groups according to symptom-to-door (StD) time (<24 or ≥24 hours). The primary outcome was 3-year all-cause mortality, and the secondary outcome was 3-year composite of all-cause mortality, recurrent MI, and hospitalization for heart failure. RESULTS: Overall, 1,827 (27.9%) patients were classified into the StD time ≥24 hours group. The StD time ≥24 hours group had higher all-cause mortality (17.0% vs 10.5%; P < 0.001) and incidence of secondary outcomes (23.3% vs 15.7%; P < 0.001) than the StD time <24 hours group. The higher all-cause mortality in the StD time ≥24 hours group was observed consistently in the subgroup analysis regarding age, sex, atypical chest pain, dyspnea, Q-wave in electrocardiogram, use of emergency medical services, hypertension, diabetes mellitus, chronic kidney disease, left ventricle dysfunction, TIMI (Thrombolysis In Myocardial Infarction) flow, and the GRACE risk score. In the multivariable analysis, independent predictors of prehospital delay were the elderly, women, nonspecific symptoms such as atypical chest pain or dyspnea, diabetes, and no use of emergency medical services. CONCLUSIONS: Prehospital delay is associated with an increased risk of 3-year all-cause mortality in patients with NSTEMI. (iCReaT Study No. C110016).

Correlation of heart rate recovery and heart rate variability with atrial fibrillation progression.

OBJECTIVE: To examine the combination of heart rate recovery (HRR) and heart rate variability (HRV) in predicting atrial fibrillation (AF) progression. METHODS: Data from patients with a first detected episode of AF who underwent treadmill exercise testing and 24-h Holter electrocardiography were retrospectively analysed. Autonomic dysfunction was verified using HRR values. Sympathetic and parasympathetic modulation was analysed by HRV. AF progression was defined as transition from the first detected paroxysmal episode to persistent/permanent AF. RESULTS: Of 306 patients, mean LF/HF ratio and HRR did not differ significantly by AF progression regardless of age (< or ≥65 years). However, when the LF/HF ratio was divided into tertiles, in patients aged <65 years, the mid LF/HF (1.60-2.40) ratio was significantly associated with lower AF progression rates and longer maintenance of normal sinus rhythm. For patients aged <65 years, less metabolic equivalents were related to higher AF progression rates. For patients aged ≥65 years, a low HRR was associated with high AF progression rates. CONCLUSION: In relatively younger age, high physical capacity and balanced autonomic nervous system regulation are important predictors of AF progression. Evaluation of autonomic function assessed by age could predict AF progression.

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.

Neutrophil-to-Lymphocyte Ratio at Emergency Room Predicts Mechanical Complications of ST-segment Elevation Myocardial Infarction.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) has been proven to be a reliable inflammatory marker. A recent study reported that elevated NLR is associated with adverse cardiovascular events in patients with ST-segment elevation myocardial infarction (STEMI). We investigated whether NLR at emergency room (ER) is associated with mechanical complications of STEMI undergoing primary percutaneous coronary intervention (PCI). METHODS: A total of 744 patients with STEMI who underwent successful primary PCI from 2009 to 2018 were enrolled in this study. Total and differential leukocyte counts were measured at ER. The NLR was calculated as the ratio of neutrophil count to lymphocyte count. Patients were divided into tertiles according to NLR. Mechanical complications of STEMI were defined by STEMI combined with sudden cardiac arrest, stent thrombosis, pericardial effusion, post myocardial infarction (MI) pericarditis, and post MI ventricular septal rupture, free-wall rupture, left ventricular thrombus, and acute mitral regurgitation during hospitalization. RESULTS: Patients in the high NLR group (> 4.90) had higher risk of mechanical complications of STEMI (P = 0.001) compared with those in the low and intermediate groups (13% vs. 13% vs. 23%). On multivariable analysis, NLR remained an independent predictor for mechanical complications of STEMI (RR = 1.947, 95% CI = 1.136-3.339, P = 0.015) along with symptom-to balloon time (P = 0.002) and left ventricular dysfunction (P < 0.001). CONCLUSION: NLR at ER is an independent predictor of mechanical complications of STEMI undergoing primary PCI. STEMI patients with high NLR are at increased risk for complications during hospitalization, therefore, needs more intensive treatment after PCI.

Optimal Dose and Type of ß-blockers in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention.

The clinical benefit of ß-blockers in modern reperfusion era is not well determined. We investigated the impact of ß-blockers in acute coronary syndrome (ACS) after percutaneous coronary intervention. From the Grand-DES registry, a patient-level pooled registry consisting of 5 Korean multicenter prospective drug-eluting stent registries, a total of 6,690 ACS patients were included. Prescription records of dose and type of ß-blockers were investigated trimonthly from discharge. Patients were categorized by the mean value of doses during the follow-up (≥50% [high-dose], ≥25% to <50% [medium-dose], and <25% [low-dose] of the full dose that was used in each randomized clinical trial) and vasodilating property of ß-blockers. Three-year cumulative risk of all-cause death, cardiac death, and myocardial infarction were assessed. Patients receiving ß-blockers were associated with a lower risk of all-cause and cardiac death compared with those not receiving ß-blockers (adjusted hazard ratio [aHR] 0.29, 95% confidence interval [CI] 0.24 to 0.35 for all-cause death; aHR 0.27, 95% CI 0.21 to 0.34 for cardiac death). Medium-dose ß-blocker group was associated with a lower risk of cardiac death compared with high- and low-dose ß-blocker groups (aHR 0.49, 95% CI 0.25 to 0.96, for high-dose; aHR 0.46, 95% CI 0.29 to 0.74, for low-dose). Patients receiving vasodilating ß-blockers were associated with a lower risk of cardiac death compared with those receiving conventional ß-blockers (aHR 0.58, 95% CI 0.40 to 0.84). In conclusion, ß-blocker therapy was associated with better clinical outcomes in patients with ACS, especially with medium-dose and vasodilating ß-blockers.

Ivabradine-Induced Torsade de Pointes in Patients with Heart Failure Reduced Ejection Fraction.

Ivabradine is a selective inhibitor of the sinoatrial node "funny" current, prolonging the slow diastolic depolarization. As it has the ability to block the heart rate selectively, it is more effective at a faster heart rate. It is recommended for the treatment of heart failure reduced ejection fraction in the presence of beta-blocker therapy for the further reduction of the heart rate. However, previous reports have shown the association of Torsade de pointes (TdP) with concurrent use of ivabradine and drugs resulting in QT prolongation or blockage of the metabolic breakdown of ivabradine. In this article, we report two cases of patients with heart failure reduced ejection fraction who developed TdP after ivabradine use. Our report highlights the need to exercise caution with the administration of ivabradine in the presence of a reduced repolarization reserve, such as QT prolongation or metabolic insufficiency.

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

OBJECTIVES: We aimed to identify mechanical and pharmacological revascularization strategies correlated with the index of microcirculatory resistance (IMR) in ST-elevation myocardial infarction (STEMI) patients. BACKGROUND: Microvascular dysfunction (MVD) after STEMI is correlated with infarct size and poor long-term prognosis, and the IMR is a useful analytical method for the quantitative assessment of MVD. However, therapeutic strategies that can reliably reduce MVD remain uncertain. METHODS: Patients with STEMI who underwent primary percutaneous coronary intervention (PCI) were enrolled. The IMR was measured with a pressure sensor/thermistor-tipped guidewire immediately after primary PCI. High IMR was defined as values ≥66th percentile of IMR in enrolled patients (IMR > 30.9 IU). RESULTS: A total of 160 STEMI patients were analyzed (high IMR = 54 patients). Clinical factors for Killip class (P=0.006), delayed hospitalization from symptom onset (P=0.004), peak troponin-I level (P=0.042), and multivessel disease (P=0.003) were associated with high IMR. Achieving final thrombolysis in myocardial infarction myocardial perfusion grade 3 tended to be associated with low IMR (P=0.119), whereas the presence of distal embolization was significantly associated with high IMR (P=0.034). In terms of therapeutic strategies that involved adjusting clinical and angiographic factors associated with IMR, preloading of third-generation P2Y12 inhibitors correlated with reducing IMR value (ß = -10.30, P < 0.001). Mechanical therapeutic strategies including stent diameter/length, preballoon dilatation, direct stenting, and thrombectomy were not associated with low IMR value (all P > 0.05), and postballoon dilatation was associated with high IMR (ß = 8.30, P=0.020). CONCLUSIONS: In our study, mechanical strategies were suboptimal in achieving myocardial salvage. Preloading of third-generation P2Y12 inhibitors revealed decreased IMR value, indicative of MVD prevention.

An analysis of vascular properties using pulse wave analysis in patients with vasovagal syncope.

BACKGROUND: Vasovagal syncope (VVS) is a common cause of recurrent syncope. Nevertheless, the exact hemodynamic mechanism has not been elucidated. Pulse wave analysis (PWA) is widely used to evaluate vascular properties, as it reflects the condition of the entire arterial system. HYPOTHESIS: Cardiovascular autonomic modulation may influence the hemodynamic mechanism and result in different vascular properties between VVS patients and healthy individuals. METHODS: We enrolled consecutive patients diagnosed with VVS on head-up tilt testing from January 2014 to August 2019. Healthy subjects were enrolled as the control group. We performed PWA on all participants. Using propensity score matching, we assembled a study population with similar baseline characteristics and compared hemodynamic parameters. RESULTS: A total of 111 VVS patients (43 ± 18 years, 72 females) and 475 healthy control subjects (48 ± 13 years, 192 females) were enrolled. Compared to the healthy control subjects, the VVS patients had a higher augmentation index (AIx) adjusted to a heart rate of 75 beats per minute (AIx@HR75, 20.5 ± 13.1% vs 16.7 ± 11.9%, P = .003). After 1:1 matched comparison (111 matched control), VVS patients consistently showed higher AIx@HR75 (20.5 ± 13.1% vs 16.7 ± 12.9%, P = .02) than the matched control group. According to age distribution, VVS patients showed significantly higher AIx@HR75 (10.6 ± 11.7% vs 2.5 ± 11.1%, P = .01) in a young age (15-33 years) group. CONCLUSIONS: VVS patients had greater arterial stiffness than healthy subjects. This is one of the plausible mechanisms of the pathophysiology of VVS.

Impact of gender on heart failure presentation in non-obstructive hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease that represents a broad spectrum of morphologic features and clinical presentations. However, little is known about the impact of gender differences in heart failure (HF) development in non-obstructive HCM. We assessed clinical and echocardiographic parameters according to gender in patients with non-obstructive HCM and evaluated the impact of gender on HF presentation and cardiovascular (CV) outcomes in this population. We investigated 202 consecutive patients with non-obstructive HCM. Clinical parameters and conventional echocardiographic measurements including tissue Doppler measurements were evaluated and compared according to gender. Additionally, left ventricular (LV) deformation was assessed with global longitudinal strain (GLS) utilizing 2D speckle tracking software. Of the 202 patients (age = 63 ± 14 years, male: female = 141: 61), 51 patients (24.8%) presented with HF and female patients had HF more frequently (52.5% vs. 12.8%, P < 0.001). Females were older, had a higher prevalence of atrial fibrillation, had increased left atrial volume (LAV), and a higher ratio of early diastolic mitral inflow to early annular velocity (E/e') than males (70 ± 12 years vs. 59 ± 14 years, P < 0.001 for age; 51.4 ± 19.3 mL/m2 vs. 40.0 [Formula: see text] 13.4 mL/m2, P < 0.001 for indexed LAV; 17.2 [Formula: see text] 6.0 vs. 13.0 [Formula: see text] 4.3, P < 0.001 for E/e'). While LV maximal thickness and LV ejection fraction were comparable between men and women, GLS was decreased significantly in female patients (- 13.5 [Formula: see text] 3.4% vs. - 15.6 [Formula: see text] 4.0%, P = 0.001 for GLS). Even after adjusting for clinical factors, female was independently associated with HF presentation (Odd ratio 5.19, 95% CI 2.24-12.03, P < 0.001). During a median follow-up duration 34.0 months, 20 patients (9.9%) had HF hospitalization or CV death. In a multivariable analysis, female gender was associated with higher risk of the composite of HF hospitalization or CV death and HF hospitalization alone than male (Adjusted hazard ratio [HR] = 3.31, 95% CI 1.17-9.35, P = 0.024 for primary composite outcome of HF hospitalization or CV death; adjusted HR = 4.78, 95% CI 1.53-14.96, P = 0.007 for HF hospitalization). In patients with non-obstructive HCM, female patients presented with HF more frequently and showed a higher risk of CV events than male patients. LA volume, E/e' and LV mechanics were different between the genders, suggesting that these might contribute to greater susceptibility to HF in women with HCM.