Basal Coronary Microvascular Resistance Predicting Death and Heart Failure in Patients Without Functional Coronary Stenosis.

BACKGROUND: Abnormal coronary microcirculation is linked to poor patient prognosis, so the aim of the present study was to assess the prognostic relevance of basal microvascular resistance (b-IMR) in patients without functional coronary stenosis.Methods and Results: Analyses of 226 patients who underwent intracoronary physiological assessment of the left anterior descending artery included primary endpoints of all-cause death and heart failure, as well as secondary endpoints of cardiovascular death and atherosclerotic vascular events. During a median follow-up of 2 years, there were 12 (5.3%) primary and 21 (9.3 %) secondary endpoints. The optimal b-IMR cutoff for the primary endpoints was 47.1 U. Kaplan-Meier curve analysis demonstrated worse event-free survival of the primary endpoints in patients with a b-IMR below the cutoff (χ2=21.178, P<0.001). b-IMR was not significantly associated with the secondary endpoints (P=0.35). A low coronary flow reserve (CFR; <2.5) had prognostic value for both endpoints (primary endpoints: χ2=11.401, P=0.001; secondary endpoints: (χ2=6.015; P=0.014), and high hyperemic microvascular resistance (≥25) was associated only with the secondary endpoints (χ2=4.420; P=0.036). Incorporating b-IMR into a clinical model that included CFR improved the Net Reclassification Index and Integrated Discrimination Improvement for predicting the primary endpoints (P<0.001 and P=0.034, respectively). CONCLUSIONS: b-IMR may be a specific marker of the risk of death and heart failure in patients without functional coronary stenosis.

Association between periodontal disease and pericardial adipose tissue in patients with cardiovascular disease.

Background: Periodontal disease (PD) is associated with an increased risk of cardiovascular disease (CVD). Pericardial adipose tissue (PAT) is known as a marker of progressive CVD. This study sought to assess the association between PD and PAT in patients with CVD. Methods: We retrospectively investigated 135 patients admitted for CVD who underwent computed tomography coronary angiography (CTCA) and periodontal examinations. Periodontal assessment using the community periodontal index (CPI) was based on the probing pocket depth around teeth. Patients with CPI ≥3 were categorized as having PD. PAT volume was measured with a quantitative semi-automated procedure using CTCA images. Patients were divided into tertiles according to PAT volume. Baseline characteristics and PD findings were compared among the tertiles. Results: Eighty-six patients were diagnosed with PD (63.7 %). Mean PAT volume was 181.4 ml, and patients were categorized as small-PAT (PAT <148.9 ml), intermediate-PAT (148.9 ml ≤ PAT ≤204.6 ml), and large-PAT (PAT >204.6 ml). The prevalence of PD was significantly higher in large-PAT (38/46, 82.6 %) than in small-PAT (18/45, 40.0 %) and intermediate-PAT (30/44, 68.2 %) patients. Multivariate logistic regression analysis showed that body weight, history of hypertension, and the presence of PD were independent predictors for large-PAT (odds ratio [OR]: 1.12, P < 0.001, OR: 3.97, P = 0.017, and OR: 4.18, P = 0.0078, respectively). Conclusion: The presence and severity of PD were significantly correlated with PAT volume, which has been associated with progressive CVD. Further prospective studies are warranted to assess the impact of PD on the onset and outcomes of CVD.

Erratum to "Association between periodontal disease and pericardial adipose tissue in patients with cardiovascular disease" [American Heart Journal Plus: Cardiol. Res. and Pract. Volume 30, 2023, 100,298].

[This corrects the article DOI: 10.1016/j.ahjo.2023.100298.].

Impact of the downstream myocardial mass on values of coronary microvascular resistance.

The assessment of hyperemic microvascular resistance (HMR) may be dependent on the assessment location in the coronary artery and the amount of partial myocardial mass (PMM) distal to the assessment locations. The aim of this study was to investigate the differences in HMR values between the distal and proximal sites in the same coronary arteries as well as the relationship between HMR and PMM. Twenty-nine vessels from 26 patients who had undergone intracoronary physiological assessments including Doppler flow velocity at the distal third part and the proximal third part in the same vessels were assessed. The mean values of HMR and PMM at the distal sites were 2.08 ± 0.75 mmHg/cm/sec and 22.2 ± 10.4 g, respectively. At the proximal sites, the values of HMR and PMM were 1.19 ± 0.33 mmHg/cm/sec and 59.9 ± 18.3 g, respectively. All HMR values at the distal sites were significantly higher than those at the proximal sites (p < 0.001). Smaller PMM at the distal sites was significantly associated with higher HMR (r = -0.544, p = 0.002) and was the strongest factor affecting the HMR values (p = 0.009), while this relationship was not observed at the proximal sites (r = -0.262, p = 0.17). The impact of PMM on HMR was diminished at assessment locations where PMM was greater than 35 g. In conclusion, a small amount of downstream myocardial mass could be related to high HMR values. The assessment location around the proximal coronary artery with over 35 g of myocardium would be appropriate to assess HMR because it minimizes the influence of the assessment location.

The impact of lesion complexity on predicting mortality of coronary artery disease patients after out-of-hospital cardiac arrest.

INTRODUCTION: Coronary artery disease (CAD) is the most frequent cause of out-of-hospital cardiac arrest (OHCA). Nevertheless, there have been limited studies focusing on the impact of lesion complexity on resuscitated CAD patients. The purpose of the present study was to investigate the association between coronary lesion complexity and the mortality of CAD patients after OHCA. METHODS: From pooled database of two centers, which comprised 706 successfully resuscitated OHCA patients, 172 patients undergoing coronary angiography were retrospectively investigated. A total of 148 patients exhibited coronary stenosis on angiogram and were included in the final analysis. Baseline characteristics, pre-and post-hospital care, general status after resuscitation and angiographical findings were compared between the patients who deceased within 30 days and those who survived and the predictors of 30-day mortality were determined. RESULTS: Ninety-four patients (63.5%) survived at 30 days. Bystander cardiopulmonary resuscitation (CPR) (Odds ratio (OR) 0.36; 95% confidence interval (CI) 0.14-0.96; P = 0.041), revascularization of coronary stenosis (OR 0.15; 95% CI 0.19-0.86; P < 0.001), GRACE risk score (OR 1.04; 95% CI 1.02-1.05; P < 0.001) and SYNTAX score (OR 1.07; 95% CI 1.01-1.13; P = 0.025) were independent predictors of 30-day mortality. As multiple predictors such as bystander CPR, GRACE score and SYNTAX score were combined, the 30-day mortality gradually deteriorated. CONCLUSIONS: In addition to bystander CPR, GRACE score and revascularization, SYNTAX score independently predicted 30-day mortality of CAD patients after OHCA.

Impact of Hemodialysis Duration on Coronary Artery Calcification Among Hemodialysis Patients Who Underwent Percutaneous Coronary Intervention.

Our study aimed to evaluate the prevalence and impact of coronary artery calcification (CAC) on hemodialysis (HD) patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). We enrolled 211 HD patients who underwent PCI (men: n = 155, age: 71 ± 1 0 years). Severe CAC was defined as calcification with an arc of 360° on intravascular ultrasound. Multivariate analysis was performed to determine the predictors of severe CAC. The impact of severe CAC on target lesion revascularization (TLR) was evaluated. Patients with severe CAC (46%) had a higher incidence of diabetes mellitus (DM) (79 vs 59%, P = .003) and longer HD duration (7.7 vs 3.4 years, P < .001) than those with non-severe CAC. Multivariate analysis demonstrated that DM, HD duration, and angiographic calcification were significant predictors for severe CAC (odds ratio 4.42, 1.13, and 6.62; P < .001, P < .001, and P < .001, respectively). After the median follow-up period of 580 days (interquartile range, 302-730 days), Kaplan-Meier curve analysis revealed that severe CAC was associated with an increased risk for TLR (χ2 12.7; P = .002). In HD patients with CAD after PCI, DM and HD duration were significant predictors for severe CAC. Furthermore, severe CAC was associated with an increased risk for TLR.

Predictors of Near-Infrared Spectroscopy-Detected Lipid-Rich Plaques by Optical Coherence Tomography-Defined Morphological Features in Patients With Acute Coronary Syndrome.

Background: Near-infrared spectroscopy (NIRS) provides the localization of lipid-rich components in coronary plaques. However, morphological features in NIRS-detected lipid-rich plaques (LRP) are unclear. Methods: A total of 140 de novo culprit lesions in 140 patients with the acute coronary syndrome (ACS) who underwent NIRS and optical coherence tomography (OCT) examinations for the culprit lesions at the time of percutaneous coronary interventions were investigated. We defined a NIRS-LRP as a lesion with a maximum lipid core burden index of 4 mm [LCBI4mm] > 500 in the culprit plaque. Clinical demographics, angiographic, and OCT findings were compared between the patients with NIRS-LRP (n = 54) vs. those without NIRS-LRP (n = 86). Uni- and multivariable logistic regression analyses were performed to examine the independent OCT morphological predictors for NIRS-LRP. Results: Clinical demographics showed no significant differences between the two groups. The angiographic minimum lumen diameter was smaller in the NIRS-LRP group than in the non- NIRS-LRP group. In OCT analysis, the minimum flow area was smaller; lipid angle, lipid length, the prevalence of thin-cap fibroatheroma, and cholesterol crystals were greater in the NIRS-LRP group than in the non-NIRS-LRP group. Plaque rupture and thrombi were more frequent in the NIRS-LRP group, albeit not significant. In a multivariable logistic regression analysis, presence of thin-cap fibroatheroma [odds ratio (OR): 2.56; 95% CI: 1.12 to 5.84; p = 0.03] and cholesterol crystals (OR: 2.90; 95% CI: 1.20 to 6.99; p = 0.02) were independently predictive of NIRS-LRP. Conclusions: In ACS culprit lesions, OCT-detected thin-cap fibroatheroma and cholesterol crystals rather than plaque rupture and thrombi were closely associated with a great lipid-core burden.

Angiographic flow velocity predicts lower limb outcomes after endovascular therapy: Application of the frame count method.

INTRODUCTION: Several factors related to lesion characteristics and endovascular therapy (EVT) procedures have been reported to affect primary patency after EVT. However, it is unknown why these factors were associated with primary patency. We hypothesized patency failure was related to poor blood flow in affected arteries. METHODS: This retrospective study included 131 consecutive patients who had received EVT with bare metal stents for peripheral artery disease caused by femoropopliteal artery lesions. Based on the tertile post-EVT flow velocity of the superficial femoral artery (SFA), patients were divided into high (n = 43), middle (n = 44), and low (n = 44) flow velocity groups. Flow velocity was measured using the frame count method. We measured incidence of major adverse limb events (MALE), composed of target lesion revascularization (TLR), non-TLR, and major amputation. RESULTS: At a median follow-up period of 22.7 months, MALE had occurred in 7 (16.3%), 10 (22.7%), and 29 (65.9%) of patients from the high, middle, and low SFA flow velocity groups, respectively (p < 0.001). Kaplan-Meier analysis showed incidence of MALE was significantly higher in the patients of low SFA flow velocity (log-rank test χ2 = 38.8, p < 0.001). Multivariate analysis found low SFA flow velocity to be an independent predictor for MALE (hazard ratio: 4.42; 95% CI: 2.27 to 8.60; p < 0.001) as was ankle-brachial index. CONCLUSION: Post-EVT SFA flow velocity for femoropopliteal artery lesions treated with bare metal stents is an independent predictor of limb patency. The frame count method for assessing arterial flow velocity is convenient and has potential for wide applications in EVT.

Risk factors and prognostic impact of post-discharge bleeding after endovascular therapy for peripheral artery disease.

This study evaluated the incidence, predictors, and impact of bleeding requiring hospitalization following successful endovascular therapy (EVT) for peripheral artery disease. Platelet inhibition after EVT reduces the risk of major adverse limb events but increases the risk of bleeding. The incidence of post-discharge bleeding after EVT, its independent predictors, and its prognostic importance in clinical practice have not been fully addressed. We evaluated 779 consecutive patients who underwent EVT. We found that 77 patients (9.9%) were hospitalized for major bleeding during follow-up after EVT (median 39 months, range 22-66 months), with almost half (48.1%) of the bleeding categorized as gastrointestinal bleeding. Significant predictors of post-discharge bleeding were hemodialysis (hazard ratio (HR), 3.12; 95% CI: 1.93 to 5.05; p < 0.001) and dual antiplatelet therapy (DAPT) use (HR, 1.87; 95% CI: 1.03 to 3.41; p = 0.041). During follow-up, the all-cause mortality-free survival rate was significantly worse in patients who had experienced major bleeding than in those who had not (log-rank test χ2 = 54.6; p < 0.001). Cox proportional hazards analysis showed that major bleeding (HR, 2.78; 95% CI: 1.90 to 4.06; p < 0.001) was an independent predictor of all-cause death after EVT. Hospitalization for post-discharge bleeding after EVT is associated with a substantially increased risk of death, even after successful EVT. We concluded that patients' predicted bleeding risk should be considered when selecting patients likely to benefit from EVT, and that the risk should be considered especially thoroughly in hemodialysis patients.

Eicosapentaenoic acid levels predict prognosis of peripheral artery disease caused by aortoiliac artery lesions.

BACKGROUND AND AIM: Eicosapentaenoic acid (EPA) has been reported to improve clinical outcome of high-risk atherosclerotic patients. We investigated whether endogenous EPA values predict prognosis of peripheral artery disease (PAD) patients. METHODS AND RESULTS: This retrospective study included 166 consecutive patients who had received endovascular therapy (EVT) for PAD caused by aortoiliac artery lesions. Patients were divided into 2 groups using median preoperative EPA value (57 µg/ml): LOW EPA (n = 83) and HIGH EPA (n = 83). We compared differences between the 2 groups in prevalence of major adverse limb events (MALE) which included target lesion revascularization (TLR), non-TLR, and major amputation, and major adverse events (MAE) which included MALE and all cause death. At a median follow-up period of 20 months, MALE had occurred in 24 LOW EPA patients (28.9%) and in 12 HIGH EPA patients (14.5%) (p = 0.04), and MAE had occurred in 41 LOW EPA patients (49.4%) and in 21 HIGH EPA patients (25.3%) (p < 0.01). Kaplan-Meier analysis showed prevalence of MALE and MAE was significantly higher in LOW EPA than in HIGH EPA (long-rank test χ2 = 8.5, p < 0.01, log-rank test χ2 = 13.2, p < 0.01, respectively). Multivariate Cox regression revealed preoperative EPA value < 57 µg/ml was an independent predictor for MALE (hazard ratio [HR]: 2.70; 95% CI: 1.35 to 5.4; p < 0.01) and MAE (HR: 2.86; 95% CI: 1.67 to 4.91; p < 0.01). CONCLUSIONS: Endogenous EPA value seems to be associated with risk of MALE and MAE after EVT in patients with PAD caused by aortoiliac artery lesions.

Clinical Outcomes after Endovascular Therapy Among Hemodialysis Patients with Peripheral Artery Disease Stratified by the Primary Kidney Disease.

OBJECTIVES: The objective of this study was to investigate the clinical characteristics of hemodialysis patients with peripheral artery disease (PAD) and the outcomes after endovascular therapy (EVT) in such patients stratified by the primary kidney disease. METHODS: This retrospective observational study evaluated 142 consecutive hemodialysis patients with symptomatic PAD who underwent EVT (men: n = 103, age: 74 ± 8 years). Patients were divided into 3 groups in accordance with the reason for hemodialysis: hypertensive nephrosclerosis (HTN [n = 26]), diabetic nephropathy (DN [n = 85]), and chronic glomerulosclerosis (CGN [n = 31]). The primary outcome was major adverse event(s) (MAEs), including target lesion revascularization, major amputation, and all-cause death. Clinical characteristics and outcomes were compared among the 3 groups. RESULTS: Patients with HTN were older (81 ± 6 years vs. 72 ± 8 years vs. 74 ± 8 years; P < 0.001) and had a shorter hemodialysis vintage (2.4 years vs. 6.8 years vs. 11.2 years; P < 0.001) than those with DN and CGN. Critical limb ischemia (CLI) affected 15 (58%) patients in the HTN group, 52 (61%) in the DN group, and 10 (32%) in the CGN group. Target lesion length was longer in patients with HTN than in those in the other groups (155 ± 101 mm vs. 108 ± 77 mm [DN] vs. 98 ± 76 mm [CGN]; P = 0.020). During a median follow-up period of 372 days (interquartile range, 198-730 days), Kaplan-Meier curve analysis revealed that HTN was associated with an increased risk for MAEs (χ2 11.6; P = 0.003). Furthermore, multivariate Cox regression analysis revealed that CLI, HTN, and B-type natriuretic peptide levels were independent predictors of MAE (hazard ratio 3.91, 2.88, and 1.00; P < 0.001, P < 0.001, and P = 0.001, respectively). CONCLUSIONS: Among hemodialysis patients with PAD, HTN was associated with an increased risk for MAEs after EVT.

Prognostic significance of thermodilution-derived coronary flow capacity in patients with deferred revascularisation.

AIMS: The aim of this study was to investigate the prognostic value of thermodilution-derived coronary flow capacity (T-CFC) in patients with stable coronary artery disease and deferred revascularisation. METHODS AND RESULTS: We evaluated 308 lesions in 308 patients with deferred revascularisation, stratifying the cohort according to T-CFC. Ischaemic T-CFC was defined as a composite of mildly, moderately, and severely reduced T-CFC. Clinical outcomes were assessed by vessel-oriented composite endpoints (VOCE) and major adverse cardiac events (MACE). VOCE and MACE occurred in 19 and 28 patients, respectively. Ischaemic T-CFC was found in 88 lesions (28.6%). Kaplan-Meier analysis revealed that lesions with ischaemic T-CFC had a significantly higher risk of both VOCE and MACE. The net reclassification index and integrated discrimination improvement index were both significantly improved when ischaemic T-CFC was added to the clinical risk model (age, sex, prior stent implantation, and lesion length) for predicting VOCE and MACE. Furthermore, ischaemic T-CFC showed significant incremental predictive ability for VOCE and MACE when compared with the clinical risk model + fractional flow reserve ≤0.8, or with the clinical model + coronary flow reserve ≤2.0. CONCLUSIONS: T-CFC categorisation improved the risk stratification for both VOCE and MACE and showed incremental prognostic value in patients with deferred revascularisation.

Determinants of visual-functional mismatches as assessed by coronary angiography and quantitative flow ratio.

OBJECTIVE: We aimed to evaluate the determinants of visual-functional mismatches between quantitative coronary angiography (QCA) and the quantitative flow ratio (QFR). BACKGROUND: The fractional flow reserve (FFR) has been established as a method to estimate the functional stenosis severity of coronary artery disease and to optimize decision-making for revascularization. The QFR is a novel angiography-derived computational index that can estimate the FFR without pharmacologically induced hyperemia or the use of pressure wire. METHODS: A total of 504 de novo intermediate-to-severe stable lesions that underwent angiographic and physiological assessments were analyzed. All lesions were divided into four groups based on the significance of visual (QCA-diameter stenosis [DS] > 50% and ≤ 50%) and functional (QFR ≤ 0.80 and > 0.80) stenosis severity. Patient characteristics, angiographic findings, and physiological indices were compared. RESULTS: One-hundred seventy-eight lesions (35.3%) showed discordant visual-functional assessments; mismatch (QCA-DS > 50% and QFR > 0.80) in 75 lesions (14.9%) and reverse mismatch (QCA-DS ≤ 50% and QFR ≤ 0.80) in 103 lesions (20.4%), respectively. Reverse mismatch was associated with non-diabetes, lower ejection fraction, higher Duke jeopardy score, and lower coronary flow reserve (CFR). Mismatch was associated with smaller QCA-DS, larger reference diameter, shorter lesion length, lower Duke jeopardy score, and higher CFR. Lesion location and microcirculatory resistance was not associated with the prevalence of mismatches. Reverse mismatch group had the higher prevalence of discordant decision-makings between QFR and FFR than the other three groups. CONCLUSIONS: The CFR and subtended myocardial mass were predictors of visual-functional mismatches between QCA-DS and the QFR. Caution should be exercised in lesions showing QCA-DS/QFR reverse mismatch.

Usefulness of Lipoprotein (a) for Predicting Outcomes After Percutaneous Coronary Intervention for Stable Angina Pectoris in Patients on Hemodialysis.

Serum lipoprotein (a) level is genetically determined and remains consistent during a person's life. Previous studies have reported that people with high lipoprotein (a) level are at a high risk of cardiac events. We investigated the association between lipoprotein (a) levels and clinical outcomes after percutaneous coronary intervention (PCI) for stable angina pectoris (SAP) in hemodialysis (HD) patients. Serum lipoprotein (a) levels were measured on admission in 410 consecutive HD patients who underwent successful PCI for SAP. Patients were divided into 2 groups: low and high group having lipoprotein (a) level <40 mg/dL (n = 297) and ≧40 mg/dL (n = 113) respectively. After PCI, the incidence of major adverse cardiac event (MACE) including cardiac death, nonfatal myocardial infarction, necessity of a new coronary revascularization procedure (coronary bypass surgery, repeat target lesion PCI, PCI for a new non-target lesion) was analyzed. At a median follow-up of 24 months (12 to 37 months), MACE occurred in 188 patients (45.6%). The rate of MACE rate was significantly higher in the high lipoprotein (a) group than in the low lipoprotein (a) group (59.2% vs 40.7%, long-rank test chi-square = 12.3; p < 0.001). Cox analysis showed that high lipoprotein (a) level (Hazard Ratio, 1.62; 95% Confidence Interval, 1.19 to 2.20; p = 0.002) was an independent predictor for MACE after PCI. In conclusion, high lipoprotein (a) level was associated with a higher incidence of MACE after PCI for SAP in HD patients.

Determinants of Pericoronary Adipose Tissue Attenuation on Computed Tomography Angiography in Coronary Artery Disease.

Background Recent studies have reported the association between pericoronary inflammation assessed by pericoronary adipose tissue attenuation (PCATA) on computed tomography angiography and worse outcomes in patients with coronary artery disease. We investigated the determinants predicting increased PCATA in patients with known or suspected coronary artery disease. Methods and Results A total of 540 patients who underwent computed tomography angiography and invasive coronary angiography were studied. Mean computed tomography attenuation values of PCAT (-190 to -30 Hounsfield units) (PCATA) were assessed at the proximal 40-mm segments of all 3 major coronary arteries by crude analysis. Univariable and multivariable analyses were performed to determine the predictors of increased PCATA surrounding the proximal right coronary artery. Mean right coronary artery-PCATA was -72.22±8.47 Hounsfield units and the average of 3-vessel PCATA was -70.24±6.60 Hounsfield units. Multivariable linear regression analysis revealed that the independent determinants of right coronary artery-PCATA were male (ß coefficient=4.965, P<0.001), left ventricular mass index (ß coefficient=0.040, P=0.025), and angiographically significant stenosis (diameter stenosis >50%) (ß coefficient=2.418, P=0.008). Sex-related determinants were NT-proBNP level (N-terminal pro-B-type natriuretic peptide; ß coefficient <0.001, P=0.026), Agatston score (ß coefficient=-0.002, P=0.010), left ventricular mass index (ß coefficient=0.041, P=0.028), and significant stenosis (ß coefficient=4.006, P<0.001) in male patients and left ventricular ejection fraction (ß coefficient=-0.217, P=0.010) and significant stenosis (ß coefficient=3.835, P=0.023) in female patients. Conclusions Right coronary artery-PCATA was associated with multiple clinical characteristics, established risk factors, and the presence of significant stenosis. Our results suggest that clinically significant factors such as sex, left ventricular hypertrophy, ejection fraction, calcification, and epicardial stenosis should be taken into account in the assessment of pericoronary inflammation using computed tomography angiography.

All Resting Physiological Indices May Not Be Equivalent　- Comparison Between the Diastolic Pressure Ratio and Resting Full-Cycle Ratio.

BACKGROUND: Differences between resting full-cycle ratio (RFR) and diastolic pressure ratio (dPR) have not been sufficiently discussed. This study aimed to investigate if there is a difference in diagnostic performance between RFR and dPR for the functional lesion assessment and to assess if there are specific characteristics for discordant revascularization decision-makings between RFR and dPR.Methods and Results:A total of 936 intermediate lesions in 776 patients who underwent measurements of fractional flow reserve (FFR), coronary flow reserve (CFR), and the index of microcirculatory resistance (IMR) were retrospectively studied. Physiological indices were measured from anonymized pressure recordings at an independent core laboratory. Both RFR and dPR measures were highly correlated (r=0.997, P<0.001), with equivalent diagnostic performance relative to FFR-based decision-makings measured by using a dichotomous threshold of 0.80 (accuracy, 79.7% vs. 80.1%, respectively, P=0.960). The rate of diagnostic discordance was 4.7% (44/936), with no RFR-/dPR+ lesions observed. An overall significant difference in FFR and CFR values were detected among RFR/dPR-based classifications. The prevalence of positive studies was significantly higher for RFR than dPR (54.3% vs. 49.6%, respectively, P=0.047) when using the cut-off value of 0.89. CONCLUSIONS: Both RFR and dPR were highly correlated, but the prevalence of positive studies was significantly different. The revascularization rate may differ significantly according to the resting index used.

Prognostic implication of global myocardial blood flow in patients with ST-segment elevation myocardial infarction.

The prognostic implications of cardiovascular magnetic resonance imaging (CMR)-derived hyperemic myocardial blood flow (MBF) in patients with ST-elevation myocardial infarction (STEMI) are unknown. This study sought to investigate the incremental prognostic value of hyperemic MBF over conventional CMR markers to identify patients with high risk of future incidence of patient-oriented composite outcomes (POCO) and major adverse cardiac events (MACE) after STEMI. A total of 237 patients who presented with STEMI were prospectively enrolled. The CMR protocol included left-ventricular ejection fraction (LVEF), late gadolinium enhancement (LGE) and microvascular obstruction (MVO) measurement, and volumetric MBF assessment. During a median follow-up of 2.6 years, 47 patients experienced POCO (primary outcome) and 21 patients had MACE. In a multivariable model, multivessel disease, LGE, MVO, and hyperemic MBF were independently associated with POCO. Addition of hyperemic MBF to the model consisting of GRACE score, multivessel disease, LVEF, LGE, and MVO significantly improved the predictive efficacy (integrated discrimination improvement 0.020, p = 0.021). Patients with low hyperemic MBF had significantly higher incidence of MACE compared to those with high hyperemic MBF in propensity score matching analysis (p = 0.018). In conclusion, CMR-derived hyperemic MBF could provide independent and incremental prognostic value over LVEF, LGE, and MVO in patients with STEMI.

Optical coherence tomography-defined plaque vulnerability in relation to functional stenosis severity stratified by fractional flow reserve and quantitative flow ratio.

OBJECTIVES: We sought to investigate that the quantitative flow ratio (QFR) might be associated with optical coherence tomography (OCT)-defined plaque vulnerability. BACKGROUND: Both functional stenosis severity and plaque instability are related to adverse clinical outcomes in patients with coronary artery disease. Recent studies have shown an association between physiological stenosis severity and the presence of thin-cap fibroatheroma (TCFA). Measurement of QFR is a novel method for rapid computational estimation of fractional flow reserve (FFR). METHODS: We investigated 327 de novo intermediate-to-severe coronary lesions in 295 stable patients who underwent OCT, FFR, and QFR computation. The lesions were divided into tertiles based on either the FFR or QFR. The OCT findings were compared among these tertiles of FFR and QFR. Each tertile was defined as follows: FFR-T1 (FFR < 0.72), FFR-T2 (0.72 ≤ FFR ≤ 0.79), and FFR-T3 (FFR > 0.79) and QFR-T1 (QFR < 0.73), QFR-T2 (0.73 ≤ QFR ≤ 0.78), and QFR-T3 (QFR > 0.78). RESULTS: The prevalence of OCT-defined TCFA showed graded differences in proportion to the QFR tertiles (25.0% vs. 12.8% vs. 6.6%, p = .003). An overall significant difference in the prevalence of TCFA was found among FFR tertiles (p = .048), although pairwise comparison did not show statistical significance. Compared with FFR-based classifications, the model that integrated the FFR and QFR categorization improved the incremental reclassification efficacy (relative integrated discrimination improvement, 0.069; p = .002; continuous net reclassification improvement, 0.356; p = .022) for predicting the presence of TCFA. CONCLUSIONS: OCT-defined plaque instability was associated with the QFR in angiographically intermediate-to-severe lesions. Compared with the FFR alone, the QFR can provide incremental efficacy in predicting the presence of TCFA.

Sex Differences in Long-Term Outcomes in Patients With Deferred Revascularization Following Fractional Flow Reserve Assessment: International Collaboration Registry of Comprehensive Physiologic Evaluation.

Background Sex-specific differences may influence prognosis after deferred revascularization following fractional flow reserve (FFR) measurement. This study sought to investigate the sex differences in long-term prognosis of patients with deferred revascularization following FFR assessment. Methods and Results A total of 879 patients (879 vessels) with deferred revascularization with FFR >0.75 who underwent FFR and coronary flow reserve measurements were enrolled from 3 countries (Korea, Japan, and Spain). Long-term outcomes were assessed in 649 men and 230 women by the patient-oriented composite outcome (POCO, a composite of any death, any myocardial infarction, and any revascularization). We applied inverse-probability weighting based on propensity scores to account for differences at baseline between women and men (age, hyperlipidemia, diabetes mellitus, diameter stenosis, lesion length, multivessel disease, FFR, coronary flow reserve. The median follow-up duration was 1855 days (745-1855 days). Median FFR values were 0.88 (0.83-0.93) in men and 0.89 (0.85-0.94) in women, respectively. The occurrences of POCO were significantly high in men compared with that in women (10.5% versus 4.2%, P=0.007). Kaplan-Meier analysis revealed that women had a significantly lower risk of POCO (χ2=7.2, P=0.007). Multivariate COX proportional hazards regression analysis revealed that age, male, diabetes mellitus, diameter stenosis, lesion length, and coronary flow reserve were independent predictors of POCO. After applying IPW, the hazard ratio of males for POCO was 2.07 (95% CI, 1.07-4.04, P=0.032). Conclusions This large multinational study reveals that long-term outcome differs between women and men in favor of women after FFR-guided revascularization deferral. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifier: NCT02186093.