Intravascular Imaging-Guided or Angiography-Guided Complex PCI.

BACKGROUND: Data regarding clinical outcomes after intravascular imaging-guided percutaneous coronary intervention (PCI) for complex coronary-artery lesions, as compared with outcomes after angiography-guided PCI, are limited. METHODS: In this prospective, multicenter, open-label trial in South Korea, we randomly assigned patients with complex coronary-artery lesions in a 2:1 ratio to undergo either intravascular imaging-guided PCI or angiography-guided PCI. In the intravascular imaging group, the choice between intravascular ultrasonography and optical coherence tomography was at the operators' discretion. The primary end point was a composite of death from cardiac causes, target-vessel-related myocardial infarction, or clinically driven target-vessel revascularization. Safety was also assessed. RESULTS: A total of 1639 patients underwent randomization, with 1092 assigned to undergo intravascular imaging-guided PCI and 547 assigned to undergo angiography-guided PCI. At a median follow-up of 2.1 years (interquartile range, 1.4 to 3.0), a primary end-point event had occurred in 76 patients (cumulative incidence, 7.7%) in the intravascular imaging group and in 60 patients (cumulative incidence, 12.3%) in the angiography group (hazard ratio, 0.64; 95% confidence interval, 0.45 to 0.89; P = 0.008). Death from cardiac causes occurred in 16 patients (cumulative incidence, 1.7%) in the intravascular imaging group and in 17 patients (cumulative incidence, 3.8%) in the angiography group; target-vessel-related myocardial infarction occurred in 38 (cumulative incidence, 3.7%) and 30 (cumulative incidence, 5.6%), respectively; and clinically driven target-vessel revascularization in 32 (cumulative incidence, 3.4%) and 25 (cumulative incidence, 5.5%), respectively. There were no apparent between-group differences in the incidence of procedure-related safety events. CONCLUSIONS: Among patients with complex coronary-artery lesions, intravascular imaging-guided PCI led to a lower risk of a composite of death from cardiac causes, target-vessel-related myocardial infarction, or clinically driven target-vessel revascularization than angiography-guided PCI. (Supported by Abbott Vascular and Boston Scientific; RENOVATE-COMPLEX-PCI ClinicalTrials.gov number, NCT03381872).

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.).

Prognostic Implications of N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Non-ST-Elevation Myocardial Infarction.

BACKGROUND: Limited data exist regarding the prognostic implications of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with non-ST-elevation myocardial infarction (NSTEMI) who undergo percutaneous coronary intervention (PCI).Methods and Results: Of 13,104 patients in the nationwide Korea Acute Myocardial Infarction Registry-National Institutes of Health, 3,083 patients with NSTEMI who underwent PCI were included in the present study. The primary endpoint was major adverse cardiovascular events (MACE) at 3 years, a composite of all-cause death, recurrent myocardial infarction, unplanned repeat revascularization, and admission for heart failure. NT-proBNP was measured at the time of initial presentation for the management of NSTEMI, and patients were divided into a low (<700 pg/mL; n=1,813) and high (≥700 pg/mL; n=1,270) NT-proBNP group. The high NT-proBNP group had a significantly higher risk of MACE, driven primarily by a higher risk of cardiac death or admission for heart failure. These results were consistent after confounder adjustment by propensity score matching and inverse probability weighting analysis. CONCLUSIONS: In patients with NSTEMI who underwent PCI, an initial elevated NT-proBNP concentration was associated with higher risk of MACE at 3 years, driven primarily by higher risks of cardiac death or admission for heart failure. These results suggest that the initial NT-proBNP concentration may have a clinically significant prognostic value in NSTEMI patients undergoing PCI.

Association between intensive care unit nursing grade and mortality in patients with cardiogenic shock and its cost-effectiveness.

BACKGROUND: Despite the high workload of cardiac intensive care unit (ICU), there is a paucity of evidence on the association between nurse workforce and mortality in patients with cardiogenic shock (CS). This study aimed to evaluate the prognostic impact of the ICU nursing grade on mortality and cost-effectiveness in CS. METHODS: A nationwide analysis was performed using the K-NHIS database. Patients diagnosed with CS and admitted to the ICU at tertiary hospitals were enrolled. ICU nursing grade was defined according to the bed-to-nurse ratio: grade1 (bed-to-nurse ratio < 0.5), grade2 (0.5 ≤ bed-to-nurse ratio < 0.63), and grade3 (0.63 ≤ bed-to-nurse ratio < 0.77) or above. The primary endpoint was in-hospital mortality. Cost-effective analysis was also performed. RESULTS: Of the 72,950 patients with CS, 27,216 (37.3%) were in ICU nursing grade 1, 29,710 (40.7%) in grade 2, and 16,024 (22.0%) in grade ≥ 3. The adjusted-OR for in-hospital mortality was significantly higher in patients with grade 2 (grade 1 vs. grade 2, 30.6% vs. 37.5%, adjusted-OR 1.14, 95% CI1.09-1.19) and grade ≥ 3 (40.6%) with an adjusted-OR of 1.29 (95% CI 1.23-1.36) than those with grade 1. The incremental cost-effectiveness ratio of grade1 compared with grade 2 and ≥ 3 was $25,047/year and $42,888/year for hospitalization and $5151/year and $5269/year for 1-year follow-up, suggesting that grade 1 was cost-effective. In subgroup analysis, the beneficial effects of the high-intensity nursing grade on mortality were more prominent in patients who received CPR or multiple vasopressors usage. CONCLUSIONS: For patients with CS, ICU grade 1 with a high-intensity nursing staff was associated with reduced mortality and more cost-effectiveness during hospitalization compared to grade 2 and grade ≥ 3, and its beneficial effects were more pronounced in subjects at high risk of CS.

Optimal Antithrombotic Therapy Beyond 1-Year After Coronary Revascularization in Patients With Atrial Fibrillation.

BACKGROUND: Currently, non-vitamin K-antagonist oral anticoagulant (NOAC) monotherapy has been suggested as the optimal antithrombotic therapy for atrial fibrillation (AF) beyond one year after coronary revascularization. The aim of this study was to compare the outcomes between NOAC monotherapy and NOAC plus antiplatelet combination therapy using real-world data. METHODS: Between 2015 and 2020, patients with AF who had received NOACs beyond one year after coronary revascularization were enrolled from Korean national insurance data. We emulated a pragmatic sequence of trials between the NOAC monotherapy and the antiplatelet combination therapy followed by propensity score matching. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCEs), a composite of all-cause death, myocardial infarction, and stroke. RESULTS: Among 206,407 person-trials from 4,465 individuals, we compared 3,275 pairs of the monotherapy and the matched combination therapy. During a median follow-up of 1.24 years, the incidence rate of MACCE was 19.4% and 20.0% per patient-year in the monotherapy group and the antiplatelet combination group, respectively (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.88-1.05; P = 0.422). Compared with the antiplatelet combination group, the monotherapy group had a significantly lower incidence rate of major bleeding, defined as intracranial bleeding or gastrointestinal bleeding requiring hospitalization (2.8% vs. 3.6% per patient-year; HR, 0.78; 95% CI, 0.62-0.97; P = 0.024). CONCLUSION: As an antithrombotic therapy for AF beyond one year after coronary revascularization, NOAC monotherapy was associated with a similar risk of MACCE and a lower risk of major bleeding compared to NOAC plus antiplatelet combination therapy.

Fractional flow reserve versus angiography-guided strategy in acute myocardial infarction with multivessel disease: a randomized trial.

AIMS: In patients with acute myocardial infarction (MI) and multivessel coronary artery disease, percutaneous coronary intervention (PCI) of non-infarct-related artery reduces death or MI. However, whether selective PCI guided by fractional flow reserve (FFR) is superior to routine PCI guided by angiography alone is unclear. The current trial sought to compare FFR-guided PCI with angiography-guided PCI for non-infarct-related artery lesions among patients with acute MI and multivessel disease. METHODS AND RESULTS: Patients with acute MI and multivessel coronary artery disease who had undergone successful PCI of the infarct-related artery were randomly assigned to either FFR-guided PCI (FFR ≤0.80) or angiography-guided PCI (diameter stenosis of >50%) for non-infarct-related artery lesions. The primary end point was a composite of time to death, MI, or repeat revascularization. A total of 562 patients underwent randomization. Among them, 60.0% underwent immediate PCI for non-infarct-related artery lesions and 40.0% were treated by a staged procedure during the same hospitalization. PCI was performed for non-infarct-related artery in 64.1% in the FFR-guided PCI group and 97.1% in the angiography-guided PCI group, and resulted in significantly fewer stent used in the FFR-guided PCI group (2.2 ± 1.1 vs. 2.5 ± 0.9, P < 0.001). At a median follow-up of 3.5 years (interquartile range: 2.7-4.1 years), the primary end point occurred in 18 patients of 284 patients in the FFR-guided PCI group and in 40 of 278 patients in the angiography-guided PCI group (7.4% vs. 19.7%; hazard ratio, 0.43; 95% confidence interval, 0.25-0.75; P = 0.003). The death occurred in five patients (2.1%) in the FFR-guided PCI group and in 16 patients (8.5%) in the angiography-guided PCI group; MI in seven (2.5%) and 21 (8.9%), respectively; and unplanned revascularization in 10 (4.3%) and 16 (9.0%), respectively. CONCLUSION: In patients with acute MI and multivessel coronary artery disease, a strategy of selective PCI using FFR-guided decision-making was superior to a strategy of routine PCI based on angiographic diameter stenosis for treatment of non-infarct-related artery lesions regarding the risk of death, MI, or repeat revascularization.

Microvascular resistance reserve: diagnostic and prognostic performance in the ILIAS registry.

AIMS: The microvascular resistance reserve (MRR) was introduced as a means to characterize the vasodilator reserve capacity of the coronary microcirculation while accounting for the influence of concomitant epicardial disease and the impact of administration of potent vasodilators on aortic pressure. This study aimed to evaluate the diagnostic and prognostic performance of MRR. METHODS AND RESULTS: A total of 1481 patients with stable symptoms and a clinical indication for coronary angiography were included from the global ILIAS Registry. MRR was derived as a function of the coronary flow reserve (CFR) divided by the fractional flow reserve (FFR) and corrected for driving pressure. The median MRR was 2.97 [Q1-Q3: 2.32-3.86] and the overall relationship between MRR and CFR was good [correlation coefficient (Rs) = 0.88, P < 0.005]. The difference between CFR and MRR increased with decreasing FFR [coefficient of determination (R2) = 0.34; Coef.-2.88, 95% confidence interval (CI): -3.05--2.73; P < 0.005]. MRR was independently associated with major adverse cardiac events (MACE) at 5-year follow-up [hazard ratio (HR) 0.78; 95% CI 0.63-0.95; P = 0.024] and with target vessel failure (TVF) at 5-year follow-up (HR 0.83; 95% CI 0.76-0.97; P = 0.047). The optimal cut-off value of MRR was 3.0. Based on this cut-off value, only abnormal MRR was significantly associated with MACE and TVF at 5-year follow-up in vessels with functionally significant epicardial disease (FFR <0.75). CONCLUSION: MRR seems a robust indicator of the microvascular vasodilator reserve capacity. Moreover, in line with its theoretical background, this study suggests a diagnostic advantage of MRR over other indices of vasodilatory capacity in patients with hemodynamically significant epicardial coronary artery disease.

Long-term outcome of thoracoscopic ablation and radiofrequency catheter ablation for persistent atrial fibrillation as a de novo procedure.

AIMS: Limited data are available regarding the efficacy of thoracoscopic ablation as the first procedure for persistent atrial fibrillation (AF). We sought to compare the long-term efficacy of thoracoscopic ablation vs. radiofrequency (RF) catheter ablation as the first procedure for persistent AF. METHODS AND RESULTS: Between February 2011 and December 2020, 575 patients who underwent ablation for persistent AF were studied. Among them, thoracoscopic ablation was performed in 281 patients, RF catheter ablation in 228, and hybrid ablation in 66. Rhythm, clinical, and safety outcomes during 7-year follow-up were compared. The patients who underwent thoracoscopic ablation were older, had a higher prevalence of stroke, and had a larger left atrial volume than those who underwent RF catheter ablation. In the propensity score-matched population (n = 306), incidences of atrial tachyarrhythmia recurrence were 51.4% in the thoracoscopic ablation group and 62.5% in the RF catheter ablation group [adjusted hazard ratio (HR) 0.869, 95% confidence interval (CI) 0.618-1.223, P = 0.420]. Stroke and total procedural adverse events were not significantly different between thoracoscopic and RF catheter ablation (2.7 vs. 2.5%, P = 0.603, and 7.1 vs. 4.8%, P = 0.374, respectively). The hybrid ablation group showed similar rhythm outcomes compared with both the thoracoscopic and the RF catheter ablation groups. At the redo procedure, pulmonary vein gaps were more frequently observed in the RF catheter ablation group (32.6%) than in the thoracoscopic ablation group (7.9%) and in the hybrid ablation group (8.8%) (P < 0.001). CONCLUSION: As a first procedure in persistent AF, thoracoscopic ablation and RF catheter ablation showed comparable efficacy, clinical, and safety outcomes during long-term follow-up.

Moderate-Intensity Statins Plus Ezetimibe vs. High-Intensity Statins After Coronary Revascularization: A Cohort Study.

PURPOSE: Whether moderate-intensity statins plus ezetimibe could be an alternative to high-intensity statins in patients with atherosclerotic cardiovascular disease is unclear. We compared the risk of adverse cardiovascular events in patients receiving moderate-intensity statins plus ezetimibe vs. high-intensity statins after a coronary revascularization procedure using data from a large cohort study. METHOD: Population-based cohort study using nationwide medical insurance data from Korea. Study participants (n = 20,070) underwent percutaneous coronary intervention or coronary artery bypass graft surgery between January 1, 2015, and December 31, 2016, and received moderate-intensity statins (atorvastatin 10-20 mg or rosuvastatin 5-10 mg) plus ezetimibe (n = 922) or high-intensity statins (atorvastatin 40-80 mg or rosuvastatin 20 mg; n = 19,148). The primary outcome was a composite of cardiovascular mortality, hospitalization for myocardial infarction (MI), hospitalization for stroke, or revascularization. RESULTS: At 12 months, the incidence rates of the primary outcome were 138.0 vs. 154.0 per 1000 person-years in the moderate-intensity stains plus ezetimibe and the high-intensity statins group, respectively. The fully adjusted hazard ratio [HR] for the primary outcome was 1.11 (95% confidence interval [CI] 0.86-1.42; p = 0.43). The multivariable-adjusted HR for a composite of cardiovascular mortality, hospitalization for MI, or hospitalization for stroke was 1.05 (95% CI 0.74-1.47; p = 0.80). During follow-up, the proportion of patients maintaining their initial lipid-lowering therapy was significantly higher in the moderate-intensity statins plus ezetimibe group than in the high-intensity statins group. CONCLUSIONS: Patients undergoing a coronary revascularization procedure who received moderate-intensity statins plus ezetimibe showed similar rates of major adverse cardiovascular events as patients who received high-intensity statins.

Comparison Between Fimasartan Versus Other Angiotensin Receptor Blockers in Patients With Heart Failure After Acute Myocardial Infarction.

BACKGROUNDS: Fimasartan is the most recently developed, potent, and long-acting angiotensin II receptor blocker (ARB). However, data are limited regarding treatment effects of fimasartan in patients with heart failure. METHODS: Between 2010 and 2016, patients who underwent coronary revascularization for myocardial infarction (MI) with heart failure and prescription of ARB at hospital discharge were enrolled from the Korean nationwide medical insurance data. Clinical outcomes were compared between patients receiving fimasartan and those receiving other ARBs (candesartan, valsartan, losartan, telmisartan, olmesartan, and irbesartan). The primary outcome was a composite of all-cause death, recurrent MI, hospitalization for heart failure, and stroke. RESULTS: Of 2,802 eligible patients, fimasartan was prescribed to 124 patients (4.4%). During a median follow-up of 2.2 years (interquartile range, 1.0-3.9), 613 events of the primary outcome occurred. There was no significant difference in the primary outcome between patients receiving fimasartan and those receiving other ARBs (adjusted hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.46-1.45). Compared with patients receiving other ARBs, those receiving fimasartan had comparable incidence of all-cause death (adjusted HR, 0.70; 95% CI, 0.30-1.63), recurrent MI (adjusted HR, 1.28; 95% CI, 0.49-3.34), hospitalization for heart failure (adjusted HR, 0.70; 95% CI, 0.27-1.84), and stroke (adjusted HR, 0.59; 95% CI, 0.18-1.96). CONCLUSION: In this nationwide cohort, fimasartan, compared with other ARBs, had comparable treatment effects for a composite of all-cause death, recurrent MI, hospitalization for heart failure, and stroke in patients with heart failure after MI.

Sex-Based Outcomes of P2Y12 Inhibitor Monotherapy After Three Months of Dual Antiplatelet Therapy in Patients Undergoing Percutaneous Coronary Intervention.

BACKGROUND: In patients undergoing percutaneous coronary intervention (PCI) in the SMART-CHOICE trial, P2Y12 inhibitor monotherapy after three months of dual antiplatelet therapy (DAPT) achieved clinical outcomes comparable to those of 12 months of DAPT. Nonetheless, the effects of sex on these outcomes remain unknown. METHODS: This open-label, non-inferiority, randomized study, conducted in 33 hospitals in South Korea, included 2,993 patients undergoing PCI with drug-eluting stents. Patients were randomly assigned to receive DAPT (aspirin plus a P2Y12 inhibitor) for three months then P2Y12 inhibitor alone for nine months, or DAPT for the entire 12 months. The primary endpoints were major adverse cardiac and cerebrovascular events (a composite of all-cause death, myocardial infarction, or stroke) 12 months after the index procedure. The bleeding endpoints were Bleeding Academic Research Consortium (BARC) bleeding types 2 to 5. RESULTS: Of the patients, 795 (26.6%) were women, who were older and had a higher prevalence of hypertension, diabetes, and dyslipidemia than men. The sexes exhibited comparable primary endpoints (adjusted hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.55-1.55; P = 0.770) and bleeding endpoints (adjusted HR, 1.07; 95% CI, 0.63-1.81; P = 0.811). P2Y12 inhibitor monotherapy vs DAPT was associated with lower risk of BARC type 2 to 5 bleeding in women (adjusted HR, 0.40; 95% CI, 0.16-0.98; P = 0.045) but the difference was not statistically significant when using the Bonferroni correction. The primary endpoints were similar between treatment groups in both sexes. CONCLUSION: In both sexes undergoing PCI, P2Y12 inhibitor monotherapy after three months of DAPT achieved similar risks of the primary endpoints and the bleeding events compared with prolonged DAPT. Therefore, the benefits of early aspirin withdrawal with ongoing P2Y12 inhibitors may be comparable in women and men. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02079194.

Safety and Efficacy of Everolimus-Eluting Bioresorbable Vascular Scaffold Versus Second-Generation Drug-Eluting Stents in Real-World Practice.

BACKGROUND: The risk of device thrombosis and device-oriented clinical outcomes with bioresorbable vascular scaffold (BVS) was reported to be significantly higher than with contemporary drug-eluting stents (DESs). However, optimal device implantation may improve clinical outcomes in patients receiving BVS. The current study evaluated mid-term safety and efficacy of Absorb BVS with meticulous device optimization under intravascular imaging guidance. METHODS: The SMART-REWARD and PERSPECTIVE-PCI registries in Korea prospectively enrolled 390 patients with BVS and 675 patients with DES, respectively. The primary endpoint was target vessel failure (TVF) at 2 years and the secondary major endpoint was patient-oriented composite outcome (POCO) at 2 years. RESULTS: Patient-level pooled analysis evaluated 1,003 patients (377 patients with BVS and 626 patients with DES). Mean scaffold diameter per lesion was 3.24 ± 0.30 mm in BVS group. Most BVSs were implanted with pre-dilatation (90.9%), intravascular imaging guidance (74.9%), and post-dilatation (73.1%) at proximal to mid segment (81.9%) in target vessel. Patients treated with BVS showed comparable risks of 2-year TVF (2.9% vs. 3.7%, adjusted hazard ratio [HR], 1.283, 95% confidence interval [CI], 0.487-3.378, P = 0.615) and 2-year POCO (4.5% vs. 5.9%, adjusted HR, 1.413, 95% CI, 0.663-3.012, P = 0.370) than those with DES. The rate of 2-year definite or probable device thrombosis (0.3% vs. 0.5%, P = 0.424) was also similar. The sensitivity analyses consistently showed comparable risk of TVF and POCO between the 2 groups. CONCLUSION: With meticulous device optimization under imaging guidance and avoidance of implantation in small vessels, BVS showed comparable risks of 2-year TVF and device thrombosis with DES. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02601404, NCT04265443.

Coronary Microcirculatory Dysfunction and Acute Cellular Rejection After Heart Transplantation.

BACKGROUND: Acute cellular rejection is a major determinant of mortality and retransplantation after heart transplantation. We sought to evaluate the prognostic implications of coronary microcirculatory dysfunction assessed by index of microcirculatory resistance (IMR) for the risk of acute cellular rejection after heart transplantation. METHODS: The present study prospectively enrolled 154 heart transplant recipients who underwent scheduled coronary angiography and invasive coronary physiological assessment 1 month after transplantation. IMR is microcirculatory resistance under maximal hyperemia. By measuring hyperemic mean transit time using 3 injections (4 mL each) of room-temperature saline under maximal hyperemia, IMR was calculated as hyperemic distal coronary pressure×hyperemic mean transit time. The primary end point was biopsy-proven acute cellular rejection of grade ≥2R during 2 years of follow-up after transplantation and was compared by using multivariable Cox proportional hazards regression according to IMR. The incremental prognostic value of IMR, in addition to the model with clinical factors, was evaluated by comparison of C-index, net reclassification index, and integrated discrimination index. RESULTS: The mean age of recipients was 51.2±13.1 years (81.2% male), and the cumulative incidence of acute cellular rejection was 19.0% at 2 years. Patients with acute cellular rejection had significantly higher IMR values at 1 month than those without acute cellular rejection (23.1±8.6 versus 16.8±11.1, P=0.002). IMR was significantly associated with the risk of acute cellular rejection (per 5-U increase: adjusted hazard ratio, 1.18 [95% CI, 1.04-1.34], P=0.011) and the optimal cutoff value of IMR to predict acute cellular rejection was 15. Patients with IMR≥15 showed significantly higher risk of acute cellular rejection than those with IMR<15 (34.4% versus 3.8%; adjusted hazard ratio, 15.3 [95% CI 3.6-65.7], P<0.001). Addition of IMR to clinical variables showed significantly higher discriminant and reclassification ability for risk of acute cellular rejection (C-index 0.87 versus 0.74, P<0.001; net reclassification index 1.05, P<0.001; integrated discrimination index 0.20, P<0.001). CONCLUSIONS: Coronary microcirculatory dysfunction assessed by IMR measured early after heart transplantation showed significant association with the risk of acute cellular rejection. In addition to surveillance endomyocardial biopsy, early stratification using IMR could be a clinically useful tool to identify patients at higher risk of future acute cellular rejection after heart transplantation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02798731.

Diagnostic performance and prognostic impact of coronary angiography-based Index of Microcirculatory Resistance assessment: A systematic review and meta-analysis.

BACKGROUND: The Index of Microcirculatory Resistance (IMR), measured with a pressure-thermistor tipped coronary guidewire has been established as a gold standard for coronary microvascular assessment. Angiography-based IMR (angio-IMR) is a novel method to derive IMR without intracoronary instrumentation or the need for adenosine. METHODS: PubMed and Embase databases were systemically searched in November 2021 for studies that measured angio-IMR. The primary outcomes were pooled sensitivity and specificity as well as the area under the curve (AUC) of the summary receiver operating characteristic curve using IMR as a reference standard. RESULTS: A total of 129 records were initially identified and 8 studies were included in the final analysis. Overall, 1653 lesions were included in this study, of which 733 were in patients presenting with ST-segment elevation myocardial infarction. Angio-IMR yielded high diagnostic performance predicting wire-based IMR with pooled sensitivity = 0.81 (95% confidence interval: 0.76, 0.85), specificity = 0.80 (0.72, 0.86), and AUC = 0.86 (0.82, 0.88), which was similar irrespective of patient presentation. When the clinical outcome was compared between high versus low angio-IMR in patients presenting with myocardial infarction, high angio-IMR predicted an increased risk of major adverse cardiac events (MACE). CONCLUSION: Our study found that coronary angio-IMR has relatively high diagnostic performance as well as prognostic values predicting MACE, supporting its use in clinical practice.

Association between patient age, microcirculation, and coronary stenosis assessment with fractional flow reserve and instantaneous wave-free ratio.

OBJECTIVES: To investigate the effect of aging on coronary stenosis functional assessment with fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR). BACKGROUND: Limited data exist regarding the impact of patient age on these coronary pressure indices. METHODS: We analyzed 514 patients with coronary stenosis interrogated with intravascular physiology. The influence of patient age on FFR, iFR, and microcirculation-related indices was investigated. Vessel-oriented composite outcome (VOCO) was assessed in the FFR-based deferred population according to iFR, coronary flow reserve (CFR), and age. RESULTS: FFR increased (r = 0.128, p = 0.004), iFR remained unchanged (r = -0.001, p = 0.980), and CFR decreased (r = -0.095, p = 0.001) with patient age. Relationship between FFR and CFR differed across age groups (r = 0.263 in <60 years old vs. r = 0.124 in ≥60 years old, p = 0.0056), whereas iFR correlated to CFR similarly regardless age (r = 0.283 in <60 years old vs. r = 0.219 in ≥60 years old, p = 0.3781). No differences were found on angiographic stenosis severity (%DS 47.4 in <60 years old and 49.8 in ≥60 years old, p = 0.317). At 5 years, FFR-based revascularisation deferral in patients ≥60 years old was associated with more VOCO when either iFR (25%) or CFR (16.9%) were abnormal, compared to patients with normal iFR (6.3%) or normal CFR (4.6%) (log-rank p < 0.001). This difference in clinical outcomes was not observed in younger patients. CONCLUSIONS: FFR values increased progressively with patient age, potentially associated with age-related changes in the coronary microcirculation. Conversely, iFR values remained unchanged across the patient age spectrum. In ≥60 years old patients with revascularisation deferral based on FFR, both abnormal iFR and CFR values were associated with worse long-term patient outcomes.

Prediction of functional results of percutaneous coronary interventions with virtual stenting and quantitative flow ratio.

BACKGROUND: The clinical value of residual quantitative flow ratio (rQFR), a novel function of QFR technique, is unknown. AIM: We investigated the clinical value of rQFR, aimed to predict residual ischemia after virtual percutaneous coronary intervention (vPCI). METHODS: This is a substudy of the COE-PERSPECTIVE registry, which investigated the prognostic value of post-PCI fractional flow reserve (FFR). From pre-PCI angiograms, QFR and rQFR were analyzed and their diagnostic performance was assessed at blinded fashion using pre-PCI FFR and post-PCI FFR as reference, respectively. The prognostic value of rQFR after vPCI was assessed according to vessel-oriented composite outcome (VOCO) at 2 years. RESULTS: We analyzed 274 patients (274 vessels) with FFR-based ischemic causing lesions (49%) from 555 screened patients. Pre-PCI QFR and FFR were 0.63 ± 0.10 and 0.66 ± 0.11 (R = 0.756, p < 0.001). rQFR after vPCI and FFR after real PCI were 0.93 ± 0.06 and 0.86 ± 0.07 (R = 0.528, p < 0.001). The mean difference between rQFR and post-PCI FFR was 0.068 (95% limit of agreement: -0.05 to 0.19). Diagnostic performance of rQFR to predict residual ischemia after PCI was good (area under the curve [AUC]: 0.856 [0.804-0.909], p < 0.001). rQFR predicted well the incidence of 2-year VOCO after index PCI (AUC: 0.712 [0.555-0.869], p = 0.041), being similar to that of actual post-PCI FFR (AUC: 0.691 [0.512-0.870], p = 0.061). rQFR ≤0.89 was associated with increased risk of 2-year VOCO (hazard ratio [HR]: 12.9 [2.32-71.3], p = 0.0035). This difference was mainly driven by a higher rate of target vessel revascularization (HR: 16.98 [2.33-123.29], p = 0.0051). CONCLUSIONS: rQFR estimated from pre-PCI angiography and virtual coronary stenting mildly overestimated functional benefit of PCI. However, it well predicted suboptimal functional result and long-term vessel-related clinical events. CLINICAL TRIAL REGISTRATION: Influence of fractional flow reserve on the Clinical OutcomEs of PERcutaneouS Coronary Intervention (COE-PESPECTIVE) Registry, NCT01873560.

Age-related changes in the coronary microcirculation influencing the diagnostic performance of invasive pressure-based indices and long-term patient prognosis.

OBJECTIVES: Investigate age-related changes in coronary microvascular function, its effect on hyperemic and non-hyperemic indices of stenosis relevance, and its prognostic implications. BACKGROUND: Evidence assessing the effect of age on fractional flow reserve (FFR), resting mean distal intracoronary pressure/mean aortic pressure (Pd/Pa), and microcirculatory function remains scarce. METHODS: This is a post hoc study of a large prospective international registry (NCT03690713) including 1134 patients (1326 vessels) with coronary stenoses interrogated with pressure and flow guidewires. Age-dependent correlations with functional indices were analyzed. Prevalences of FFR, resting Pd/Pa, and coronary flow reserve (CFR) classification agreement were assessed. At 5 years follow-up, the relation between resting Pd/Pa, CFR, and their age-dependent implications on FFR-guided percutaneous coronary intervention (PCI) deferral (deferred if FFR > 0.80) were investigated using vessel-oriented composite outcomes (VOCO) composed of death, myocardial infarction, and repeated revascularization. RESULTS: Age correlated positively with FFR (r = 0.08, 95% confidence interval [CI]: 0.03 to 0.13, p = 0.005), but not with resting Pd/Pa (r = -0.03, 95% CI:-0.09 to 0.02, p = 0.242). CFR correlated negatively with age (r = -0.15, 95% CI: -0.21 to -0.10, p < 0.001) due to a significant decrease in maximal hyperemic flow in older patients. Patients over 60 years of age with FFR-guided deferred-PCI abnormal resting Pd/Pa or abnormal CFR had increased risk of VOCO (hazard ratio [HR]: 2.10, 95% CI: 1.15 to 4.36, p = 0.048; HR: 2.46, 95% CI:1.23 to 4.96, p = 0.011; respectively). CONLUSIONS: Aging is associated with decrease in microcirculatory vasodilation, as assessed with adenosine-based methods like CFR. In patients older than 60 years in whom PCI is deferred according to FFR > 0.80, CFR and resting Pd/Pa have an incremental value in predicting future vessel-oriented patient outcomes.

Determination of [N-13]-ammonia extraction fraction in patients with coronary artery disease by calibration to invasive coronary and fractional flow reserve.

BACKGROUND: This study presents a new extraction fraction (EF) model based on physiological measures of invasive coronary flow reserve (CFR) and fractional flow reserve (FFR) in patients with suspected coronary artery disease (CAD) and normal index microcirculatory resistance (IMR). To ascertain the clinical relevance of the new EFs, flow measurements using the newly patient-determined EFs were compared to flow measurements using traditional animal-determined EFs. METHODS: 39 patients were retrospectively selected that included a total of 91 vascular territories with invasive coronary angiography physiological measures. [N-13]-ammonia dynamic rest/adenosine-stress PET imaging was conducted in all patients and absolute myocardial flow was estimated using four published compartmental models. The extraction fraction during hyperemic flow was iteratively estimated by maximizing the agreement between invasive CFR and FFR with the non-invasive analogs myocardial flow reserve (MFR) and relative flow reserve (RFR) at similar physiological states, respectively. RESULTS: Using the new patient-determined EFs, agreement between CFR vs MFR for Model 1 and 2 was moderate and poor for Model 3 and 4. All models showed moderate agreement for FFR vs RFR. When using published models of animal-determined EFs, agreement between CFR vs MFR remained moderate for Model 1 and 2, and poor for Model 3 and 4. Similarly, all models showed moderate agreement for FFR vs RFR using animal-determined EF values. None of the observed differences were statistically significant. CONCLUSIONS: Flow measurements using extraction fraction correction for [N-13]-ammonia based on calibration to invasive intracoronary angiography physiological measures in patients with CAD were not discordant from those reported in the literature. Either patient-determined or traditional animal-determined EF correction, when used with the appropriate flow model, yields moderate agreement with invasive measurements of coronary flow reserve and fractional flow reserve.

Association Between Preexisting Elevated Left Ventricular Filling Pressure and Clinical Outcomes of Future Acute Myocardial Infarction.

BACKGROUND: Because no data were available regarding the effect of preexisting left ventricular filling pressure (LVFP) on clinical outcomes in patients with acute myocardial infarction (AMI), we evaluated whether preexisting high LVFP can determine outcomes of subsequent AMI events.Methods and Results:Among 399,613 subjects who underwent echocardiography for various reason from August 2004 to June 2019, 231 had experienced subsequent AMI and were stratified according to preexisting LVFP: low LVFP (E/e' ≤14) and high LVFP (E/e' >14). The primary outcome was cardiac death at 30 days and 1 year after AMI. Overall, 19.5% had high LVFP prior to AMI events. Preexisting high LVFP was associated with an increased risk of cardiac death at 30 days (3.8% vs. 11.6%; adjusted hazard ratio (HR) 4.56, 95% confidence interval (CI) 1.20-17.24, P=0.026) and 1 year after AMI (7.9% vs. 35.9%; adjusted HR 4.14, 95% CI 1.79-9.57, P<0.001). Preexisting E/e' as a continuous value was significantly associated with 1-year risk of cardiac death (adjusted HR 1.08, 95% CI 1.02-1.15, P=0.007). Follow-up echocardiography showed that patients with high LVFP did not show improvement in systolic or diastolic function. CONCLUSIONS: Preexisting high LVFP was associated with poor clinical course and 1-year cardiac death after subsequent AMI, as well as no improvement in systolic or diastolic function.

Differential Prognostic Implications of Vasoactive Inotropic Score for Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock According to Use of Mechanical Circulatory Support.

OBJECTIVES: To identify whether the prognostic implications of Vasoactive Inotropic Score according to use of mechanical circulatory support differ in the treatment of acute myocardial infarction complicated by cardiogenic shock. DESIGN: A multicenter retrospective and prospective observational cohort study. SETTING/PATIENT: The REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy registry includes 1,247 patients with cardiogenic shock from 12 centers in Korea. A total of 836 patients with acute myocardial infarction complicated by cardiogenic shock were finally selected, and the study population was stratified by quartiles of Vasoactive Inotropic Score (< 10, 10-30, 30-90, and > 90) for the present study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Primary endpoint was in-hospital mortality and secondary endpoint was follow-up mortality. Among the study population, 326 patients (39.0%) received medical treatment alone, 218 (26.1%) received intra-aortic balloon pump, and 292 (34.9%) received extracorporeal membrane oxygenation. In-hospital mortality occurred in 305 patients (36.5%) and was significantly higher in patients with higher Vasoactive Inotropic Score (15.6%, 20.8%, 40.2%, and 67.3%, for < 10, 10-30, 30-90, and > 90; p < 0.001). Vasoactive Inotropic Score showed better ability to predict in-hospital mortality in acute myocardial infarction patients with cardiogenic shock who received medical treatment alone (area under the curve: 0.797; 95% CI, 0.728-0.865) than in those who received intra-aortic balloon pump (area under the curve, 0.704; 95% CI, 0.625-0.783) or extracorporeal membrane oxygenation (area under the curve, 0.644; 95% CI, 0.580-0.709). The best cutoff value of Vasoactive Inotropic Score for the prediction of in-hospital mortality also differed according to the use of mechanical circulatory support (16.5, 40.1, and 84.0 for medical treatment alone, intra-aortic balloon pump, and extracorporeal membrane oxygenation, respectively). There was a significant interaction between Vasoactive Inotropic Score as a continuous value and the use of mechanical circulatory support including intra-aortic balloon pump (interaction-p = 0.006) and extracorporeal membrane oxygenation (interaction-p < 0.001) for all-cause mortality during follow-up. CONCLUSIONS: High Vasoactive Inotropic Score was associated with significantly higher in-hospital and follow-up mortality in patients with acute myocardial infarction complicated by cardiogenic shock. The predictive value of Vasoactive Inotropic Score for mortality was significantly higher in acute myocardial infarction patients with cardiogenic shock treated by medical treatment alone than in those treated by mechanical circulatory support such as intra-aortic balloon pump or extracorporeal membrane oxygenation.