Effects of age on microvascular function in patients with normal coronary arteries.

BACKGROUND: It has been suggested that coronary microvascular function decreases with age, irrespective of the presence of epicardial atherosclerosis. AIMS: Our aim is to quantitatively investigate the effects of age on microvascular function in patients with normal coronary arteries. METHODS: In 314 patients with angina with no obstructive coronary artery disease (ANOCA), microcirculatory function was tested using the continuous thermodilution method. In 305 patients, the association between age and both resting and hyperaemic myocardial blood flow (Q), microvascular resistance (Rµ), absolute coronary flow reserve (CFR) and microvascular resistance reserve (MRR) was assessed. In addition, patients were divided into 3 groups to test for differences based on age quartiles (≤52 years [24.9%], 53-64 years [49.2%], ≥65 years [25.9%]). RESULTS: The mean age was 59±9 years with a range from 22 to 79 years. The mean resting Q (Qrest) was not different in the 3 age groups (88±34 mL/min, 82±29 mL/min, and 86±38 mL/min, R2=0.001; p=0.62). A trend towards a decreasing mean hyperaemic Q (Qmax) was observed with increasing age (223±79 mL/min, 209±84 mL/min, 200±80 mL/min, R2=0.010; p=0.083). The mean resting Rµ (Rµ,rest) were 1,204±460 Wood units (WU), 1,260±411 WU, and 1,289±455 WU (p=0.23). The mean hyperaemic Rµ (Rµ,hyp) increased significantly with advancing age (429±149 WU, 464±164 WU, 503±162 WU, R2=0.026; p=0.005). Consequently, MRR decreased with age (3.2±1.2, 3.1±1.0, 2.9±0.9; p=0.038). This trend was present in both the patients with (n=121) and without (n=184) coronary microvascular dysfunction (CMD). CONCLUSIONS: There is an age-dependent physiological increase in minimal microvascular resistance and decrease in microvascular function, which is represented by a decreased MRR and is independent of atherosclerosis. The age-dependent decrease in MRR was present in both patients with and without CMD and was most evident in patients with smooth coronary arteries.

Negative selection bias for women inclusion in a clinical trial.

INTRODUCTION: Despite the growing awareness towards the importance of adequate representation of women in clinical trials among patients treated with percutaneous coronary intervention (PCI), available evidence continues to demonstrate a skewed distribution of study populations in favour of men. METHODS AND RESULTS: In this pre-specified analysis from the MASTER DAPT screening log and trial, we aimed to investigate the existence of a negative selection bias for women inclusion in a randomized clinical trial. A total of 2847 consecutive patients who underwent coronary revascularization across 65 participating sites, during a median of 14 days, were entered in the screening log, including 1749 (61.4%) non-high bleeding risk (HBR) and 1098 (38.6%) HBR patients, of whom 109 (9.9%) consented for trial participation. Female patients were less represented in consented versus non-consented HBR patients (22% versus 30%, absolute standardized difference: 0.18) and among non-consented eligible versus consented eligible patients (absolute standardized difference 0.14). The observed sex gap was primarily due investigators' choice not to offer study participation to females because deemed at very high risk of bleeding and/or ischemic complications, and only marginally to a slightly higher propensity of females compared to males to refuse study participation. CONCLUSIONS: Female HBR patients undergoing PCI are less prevalent, but also less likely to participate in the trial than male patients, mainly due to investigators' preference.

Consecutive or selectively included high bleeding risk patients in the MASTER DAPT screening log and trial.

AIMS: Screening logs have the potential to appraise the actual prevalence and distribution of predefined patient subsets, avoiding selection biases, which are inevitably and potentially present in randomised trials and real-world registries, respectively. We aimed to assess the prevalence of high bleeding risk (HBR) characteristics in the real world and the external validity of the MASTER DAPT trial. METHODS AND RESULTS: All consecutive patients who underwent percutaneous coronary intervention (PCI) for at least two consecutive weeks across 65 sites participating in the trial were entered into a screening log. Of 2,847 consecutive patients, 1,098 (38.6 %) were HBR and 109 (9.9 %) consented for trial participation. PRECISE-DAPT score ≥ 25 was the most frequent HBR feature, followed by advanced age, use of oral anticoagulation (OAC) and anaemia. Compared with consecutive HBR patients, consenting patients were older (≥ 75 years: 69 % versus 62 %, absolute standardized difference [SD] 0.16), more frequently male (78 % versus 71 %, absolute SD 0.18), had higher use of OAC (38 % versus 20 %, absolute SD 0.39), treatment with steroids or nonsteroidal anti-inflammatory drugs (10 % versus 5 %, SD 0.16), and prior cerebrovascular events (10 % versus 6 %, absolute SD 0.18) but lower PRECISE DAPT score ≥ 25 (54 % versus 66 %, absolute SD 0.24). CONCLUSIONS: The HBR criteria distribution differed between consecutive versus selectively included HBR patients, suggesting the existence of selection biases in the trial population.

Prehospital crushed versus integral prasugrel loading dose in STEMI patients with a large myocardial area.

BACKGROUND: The effect of administering a crushed prasugrel loading dose is uncertain in patients presenting with a large myocardial infarction and ST-segment elevation myocardial infarction (STEMI). AIMS: The aim of this study was to investigate if patients with a large myocardial infarction may benefit from prehospital administration of a crushed prasugrel loading dose. METHODS: Patients from the CompareCrush trial with an available ambulance electrocardiography (ECG) were included in the study. An independent core laboratory confirmed a prehospital large myocardial area. We compared pre- and postprocedural angiographic markers, including Thrombolysis in Myocardial Infarction (TIMI) 3 flow in the infarct-related artery, high thrombus burden, and myocardial blush grade 3, in STEMI patients with and without a prehospital large myocardial area. RESULTS: Ambulance ECG was available for 532 patients, of whom 331 patients were identified with a prehospital large myocardial area at risk. Crushed prasugrel significantly improved postprocedural TIMI 3 flow rates in STEMI patients with a prehospital large myocardial area at risk (92% vs 79%, odds ratio [OR] 3.00, 95% confidence interval [CI]: 1.50-6.00) but not in STEMI patients without a prehospital large myocardial area at risk (91% vs 95%, OR 0.47, 95% CI: 0.14-1.57; pinteraction=0.009). CONCLUSIONS: Administration of crushed prasugrel may improve postprocedural TIMI 3 flow in STEMI patients with signs of a large myocardial area at risk on the ambulance ECG. The practice of crushing tablets of prasugrel loading dose might, therefore, represent a safe, fast and cost-effective strategy to improve myocardial reperfusion in this high-risk STEMI subgroup undergoing primary percutaneous coronary intervention.

Incidence of ventricular arrhythmias in patients with chronic total coronary occlusion: Results of the VACTOR study.

Background: A chronic total coronary occlusion (CTO) is associated with ventricular arrhythmias (VA) in patients with an implantable cardioverter-defibrillator (ICD). Limited data is available on the incidence of VA in CTO patients without an ICD. Objectives: To investigate the incidence of sustained VA in CTO patients after successful CTO revascularization and in patients with untreated CTO or failed CTO revascularization. Methods: Prospective, multicenter observational pilot study including CTO patients who were not eligible for an ICD and had a left ventricular ejection fraction >35 %. We enrolled patients with a successful CTO revascularization (group A) and patients with untreated CTO or failed CTO revascularization (group B). All patients received an implantable loop recorder with remote monitoring. The primary endpoint was sustained VA. Results: Ninety patients were enrolled (mean age 63 ± 10 years, 83.3 % man, mean LVEF 55 ± 8 %). Group A (n = 45) had a higher prevalence of CTO in the left anterior descending artery in comparison to group B (n = 45) (28.9 % versus 4.4 %, P = 0.002). Other baseline characteristics were similar. During a median follow-up time of 26 months (IQR, 19-35), five patients (5.6 %) had a sustained VA. There was no difference in the incidence of sustained VA between groups (3-year cumulative event rate: 8.8 % (group A) versus 4.5 % (Group B), log-rank P = 0.71). Conclusion: Patients with an CTO, who do not qualify for an ICD, have a substantial risk of sustained VA. In our study the incidence was not different between patients with revascularized and those with untreated CTO.

Abbreviated or Standard Dual Antiplatelet Therapy by Sex in Patients at High Bleeding Risk: A Prespecified Secondary Analysis of a Randomized Clinical Trial.

Importance: Abbreviated dual antiplatelet therapy (DAPT) reduces bleeding with no increase in ischemic events in patients at high bleeding risk (HBR) undergoing percutaneous coronary intervention (PCI). Objectives: To evaluate the association of sex with the comparative effectiveness of abbreviated vs standard DAPT in patients with HBR. Design, Setting, and Patients: This prespecified subgroup comparative effectiveness analysis followed the Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated vs Standard DAPT Regimen (MASTER DAPT) trial, a multicenter, randomized, open-label clinical trial conducted at 140 sites in 30 countries and performed from February 28, 2017, to December 5, 2019. A total of 4579 patients with HBR were randomized at 1 month after PCI to abbreviated or standard DAPT. Data were analyzed from July 1 to October 31, 2022. Interventions: Abbreviated (immediate DAPT discontinuation, followed by single APT for ≥6 months) or standard (DAPT for ≥2 additional months, followed by single APT for 11 months) treatment groups. Main Outcomes and Measures: One-year net adverse clinical events (NACEs) (a composite of death due to any cause, myocardial infarction, stroke, or major bleeding), major adverse cardiac or cerebral events (MACCEs) (a composite of death due to any cause, myocardial infarction, or stroke), and major or clinically relevant nonmajor bleeding (MCB). Results: Of the 4579 patients included in the analysis, 1408 (30.7%) were women and 3171 (69.3%) were men (mean [SD] age, 76.0 [8.7] years). Ischemic and bleeding events were similar between sexes. Abbreviated DAPT was associated with comparable NACE rates in men (hazard ratio [HR], 0.97 [95% CI, 0.75-1.24]) and women (HR, 0.87 [95% CI, 0.60-1.26]; P = .65 for interaction). There was evidence of heterogeneity of treatment effect by sex for MACCEs, with a trend toward benefit in women (HR, 0.68 [95% CI, 0.44-1.05]) but not in men (HR, 1.17 [95% CI, 0.88-1.55]; P = .04 for interaction). There was no significant interaction for MCB across sex, although the benefit with abbreviated DAPT was relatively greater in men (HR, 0.65 [95% CI, 0.50-0.84]) than in women (HR, 0.77 [95% CI, 0.53-1.12]; P = .46 for interaction). Results remained consistent in patients with acute coronary syndrome and/or complex PCI. Conclusions and Relevance: These findings suggest that women with HBR did not experience higher rates of ischemic or bleeding events compared with men and may derive particular benefit from abbreviated compared with standard DAPT owing to these numerically lower rates of events. Trial Registration: ClinicalTrials.gov Identifier: NCT03023020.

First randomised controlled trial comparing the sirolimus-eluting bioadaptor with the zotarolimus-eluting drug-eluting stent in patients with de novo coronary artery lesions: 12-month clinical and imaging data from the multi-centre, international, BIODAPTOR-RCT.

Background: The DynamX™ bioadaptor is the first coronary implant technology with a unique mechanism of unlocking the bioadaptor frame after polymer resorption over 6 months, uncaging the vessel while maintaining a dynamic support to the vessel. It aims to achieve the acute performance of drug-eluting stents (DES) with the advantages of restoration of vessel function. Methods: This international, single blinded, randomised controlled (1:1) trial compared a sirolimus-eluting bioadaptor with a contemporary zotarolimus-eluting stent (DES) in 34 hospitals in Europe, Japan and New Zealand. Patients with de novo coronary lesions and absence of acute myocardial infarction were enrolled from January 2021 to Feburary 2022. The implantation of the bioadaptor followed the standards of DES. An imaging subset of 100 patients had angiographic and intravascular ultrasound assessments, and 20 patients additionally optical coherence tomography. Data collection will continue through 5 years, we herein report 12-month data based on an intention-to-treat population. This trial is registered at ClinicalTrials.gov (NCT04192747). Findings: 445 patients were randomised between January 2021 and February 2022. Device, lesion and procedural success rates, and acute gain were similar amongst the groups. The primary endpoint, 12-month target lesion failure, was 1.8% [95% CI: 0.5; 4.6] (n = 4) versus 2.8% [95% CI: 1.0; 6.0] (n = 6), pnon-inferiority < 0.001 for the bioadaptor and the DES, respectively (Δ-1.0% [95% CI: -3.3; 1.4]). One definite or probable device thrombosis occurred in each group. The 12-month imaging endpoints showed superior effectiveness of the bioadaptor such as in-device late lumen loss (0.09 mm [SD 0.34] versus 0.25 mm [SD 0.39], p = 0.04), and restored compliance and cyclic pulsatility (%mid in-device lumen area change of 7.5% versus 2.7%, p < 0.001). Interpretation: This is the first randomised controlled trial comparing the novel bioadaptor technology against a contemporary DES. The bioadaptor demonstrated similar acute performance and 12-month clinical outcomes, and superior imaging endpoints including restoration of vessel function. Funding: The study was funded by Elixir Medical.

Direct Stenting versus Conventional Stenting in Patients with ST-Segment Elevation Myocardial Infarction-A COMPARE CRUSH Sub-Study.

BACKGROUND: Direct stenting (DS) compared with conventional stenting (CS) after balloon predilatation may reduce distal embolization during percutaneous coronary intervention (PCI), thereby improving tissue reperfusion. In contrast, DS may increase the risk of stent underexpansion and target lesion failure. METHODS: In this sub-study of the randomized COMPARE CRUSH trial (NCT03296540), we reviewed the efficacy of DS versus CS in a cohort of contemporary, pretreated ST-segment elevation myocardial infarction (STEMI) patients undergoing primary PCI. We compared DS versus CS, assessing (1) stent diameter in the culprit lesion, (2) thrombolysis in myocardial infarction (TIMI) flow in the infarct-related artery post-PCI and complete ST-segment resolution (STR) one-hour post-PCI, and (3) target lesion failure at one year. For proportional variables, propensity score weighting was applied to account for potential treatment selection bias. RESULTS: This prespecified sub-study included 446 patients, of whom 189 (42%) were treated with DS. Stent diameters were comparable between groups (3.2 ± 0.5 vs. 3.2 ± 0.5 mm, p = 0.17). Post-PCI TIMI 3 flow and complete STR post-PCI rates were similar between groups (DS 93% vs. CS 90%, adjusted OR 1.16 [95% CI, 0.56-2.39], p = 0.69, and DS 72% vs. CS 58%, adjusted OR 1.29 [95% CI 0.77-2.16], p = 0.34, respectively). Moreover, target lesion failure rates at one year were comparable (DS 2% vs. 1%, adjusted OR 2.93 [95% CI 0.52-16.49], p = 0.22). CONCLUSION: In this contemporary pretreated STEMI cohort, we found no difference in early myocardial reperfusion outcomes between DS and CS. Moreover, DS seemed comparable to CS in terms of stent diameter and one-year vessel patency.

Comparison of Supraflex Cruz 60 µm Versus Ultimaster Tansei 80 µm Stent Struts in High Bleeding Risk PCI Patients: Study design and Rational of Compare 60/80 HBR trial.

Up to 45% of patients who underwent percutaneous coronary intervention (PCI) may have a high bleeding risk (HBR), depending on the bleeding risk definition.1 This condition is often associated with an enhanced risk of thrombotic events with a negative impact on short- and long-term outcomes,2-8 making the choice of an appropriate antithrombotic regimen after PCI particularly challenging. Advances in stent technologies, in which the introduction of newer generations of thinner strut drug-eluting stents (DES), have significantly reduced the rate of thrombotic complications and may justify a shorter dual antiplatelet therapy (DAPT) duration. Both in vitro and in vivo studies have shown that local hemodynamic factors may critically affect the natural history of atherosclerosis. Strut thickness correlates with flow disturbances and endothelial shear stress. Flow separation within struts determines areas of recirculation with low endothelial shear stress which promotes local concentration of activated platelets.9 By mitigating inflammation, vessel injury, and neointimal proliferation, thin and streamlined struts have been associated with faster vascular healing and re-endothelization and have resulted in lower rates of thrombotic events after PCI.10,11 The use of thin strut and ultra-thin strut stents may lead to a favorable trade-off in bleeding and ischemic events in patients with HBR. However, dedicated studies evaluating the performance of thin strut versus ultrathin strut stents in patients with HBR are lacking.

Continuous Versus Bolus Thermodilution-Derived Coronary Flow Reserve and Microvascular Resistance Reserve and Their Association With Angina and Quality of Life in Patients With Angina and Nonobstructive Coronaries: A Head-to-Head Comparison.

Background Coronary flow reserve (CFR) and microvascular resistance reserve (MRR) are physiological parameters to assess coronary microvascular dysfunction. CFR and MRR can be assessed using bolus or continuous thermodilution, and the correlation between these methods has not been clarified. Furthermore, their association with angina and quality of life is unknown. Methods and Results In total, 246 consecutive patients with angina and nonobstructive coronary arteries from the multicenter Netherlands Registry of Invasive Coronary Vasomotor Function Testing (NL-CFT) were investigated. The 36-item Short Form Health Survey Quality of Life and Seattle Angina questionnaires were completed by 153 patients before the invasive measurements. CFR and MRR were measured consecutively with bolus and continuous thermodilution. Mean continuous thermodilution-derived coronary flow reserve (CFRabs) was significantly lower than mean bolus thermodilution-derived coronary flow reserve (CFRbolus) (2.6±1.0 versus 3.5±1.8; P<0.001), with a modest correlation (ρ=0.305; P<0.001). Mean continuous thermodilution-derived microvascular resistance reserve (MRRabs) was also significantly lower than mean bolus thermodilution-derived MRR (MRRbolus) (3.1±1.1 versus 4.2±2.5; P<0.001), with a weak correlation (ρ=0.280; P<0.001). CFRbolus and MRRbolus showed no correlation with any of the angina and quality of life domains, whereas CFRabs and MRRabs showed a significant correlation with physical limitation (P=0.005, P=0.009, respectively) and health (P=0.026, P=0.012). In a subanalysis in patients in whom spasm was excluded, the correlation further improved (MRRabs versus physical limitation: ρ=0.363; P=0.041, MRRabs versus physical health: ρ=0.482; P=0.004). No association with angina frequency and stability was found. Conclusions Absolute flow measurements using continuous thermodilution to calculate CFRabs and MRRabs weakly correlate with, and are lower than, the surrogates CFRbolus and MRRbolus. Absolute flow parameters showed a relationship with physical complaints. No relationship with angina frequency and stability was found.

Coronary Vascular (DYS) Function and Invasive Physiology Assessment: Insights into Bolus and Continuous Thermodilution Methods.

A considerable number of patients with angina or myocardial ischemia have no significant coronary artery disease on invasive angiography. In recent years, several steps towards a better comprehension of the pathophysiology of these conditions, angina or ischemia with non-obstructive coronary arteries (ANOCA/INOCA), have been made. Nevertheless, several gaps in knowledge still remain. This review is intended to provide a comprehensive overview of ANOCA and INOCA, with a particular focus on pathophysiology, recent diagnostic innovations, gaps in knowledge and treatment modalities.

Impact of chronic kidney disease and diabetes on clinical outcomes in women undergoing PCI.

BACKGROUND: For women undergoing drug-eluting stent (DES) implantation, the individual and combined impact of chronic kidney disease (CKD) and diabetes mellitus (DM) on outcomes is uncertain. AIMS: We sought to assess the impact of CKD and DM on prognosis in women after DES implantation. METHODS: We pooled patient-level data on women from 26 randomised controlled trials comparing stent types. Women receiving DES were stratified into 4 groups based on CKD (defined as creatine clearance <60 mL/min) and DM status. The primary outcome at 3 years after percutaneous coronary intervention was the composite of all-cause death or myocardial infarction (MI); secondary outcomes included cardiac death, stent thrombosis and target lesion revascularisation. RESULTS: Among 4,269 women, 1,822 (42.7%) had no CKD/DM, 978 (22.9%) had CKD alone, 981 (23.0%) had DM alone, and 488 (11.4%) had both conditions. The risk of all-cause death or MI was not increased in women with CKD alone (adjusted hazard ratio [adj. HR] 1.19, 95% confidence interval [CI]: 0.88-1.61) nor DM alone (adj. HR 1.27, 95% CI: 0.94-1.70), but was significantly higher in women with both conditions (adj. HR 2.64, 95% CI: 1.95-3.56; interaction p-value <0.001). CKD and DM in combination were associated with an increased risk of all secondary outcomes, whereas alone, each condition was only associated with all-cause death and cardiac death. CONCLUSIONS: Among women receiving DES, the combined presence of CKD and DM was associated with a higher risk of the composite of death or MI and of any secondary outcome, whereas alone, each condition was associated with an increase in all-cause and cardiac death.

Outcomes with P2Y12 inhibitor monotherapy after PCI according to bleeding risk: A Bayesian meta-analysis.

BACKGROUND: P2Y12 inhibitor monotherapy is a promising novel strategy to reduce bleeding complications compared to dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). In order to personalise treatment with DAPT based on patients' bleeding risk, we compared outcomes after PCI between P2Y12 inhibitor monotherapy and DAPT according to bleeding risk. METHODS: A search for randomized clinical trials (RCTs) comparing P2Y12 inhibitor monotherapy after a short period of DAPT to standard DAPT after PCI was performed. Outcome differences between treatment groups regarding major bleedings, major adverse cardiac and cerebral events (MACCE) and net adverse clinical events (NACE) were assessed with hazard ratios (HRs) and corresponding credible intervals (CrI) according a Bayesian random effects model in patients with and without high bleeding risk (HBR). RESULTS: Five RCTs including 30,084 patients were selected. P2Y12 inhibitor monotherapy compared to DAPT reduced major bleedings in the total population (HR: 0.65, 95 % CrI: 0.44 to 0.92). The HRs of the HBR and non-HBR subgroups showed a similar reduction of bleedings for monotherapy (HBR: HR 0.66, 95 % CrI: 0.25 to 1.74; non-HBR: HR 0.63, 95 % CrI: 0.36 to 1.09). No notable differences between treatments on MACCE and NACE were observed in either sub-group or in the total population. CONCLUSIONS: Regardless of bleeding risk, P2Y12 inhibitor monotherapy is the favourable choice after PCI regarding major bleedings and does not increase ischemic events compared to DAPT. This suggests that bleeding risk is not decisive when considering P2Y12 inhibitor monotherapy.

Provisional Strategy for Left Main Stem Bifurcation Disease: A State-of-the-Art Review of Technique and Outcomes.

Left main coronary artery (LMA) disease jeopardizes a large area of myocardium and increases the risk of major adverse cardiovascular events. LMCA disease is found in 5% to 7% of all diagnostic coronary angiographies, and more than 80% of the patients enrolled in recent large randomized controlled left main trials had distal left main bifurcation or trifurcation disease. Emerging clinical evidence from prospective all-comer registries and randomized trials has provided a solid basis for percutaneous coronary intervention as a treatment option in selected patients with unprotected LMCA disease; however, to date, no uniform recommendations as to optimal stenting strategy for LMCA bifurcation lesions exist. This review provides an overview of provisional stenting technique and escalation to 2-stent strategies in LMCA bifurcation lesions. Data from randomized controlled trials and registries are reviewed. Technical characteristics of optimal provisional LMCA stenting technique and angiographic and intravascular determinants of escalation are also summarized.

Abbreviated or Standard Antiplatelet Therapy in HBR Patients: Final 15-Month Results of the MASTER-DAPT Trial.

BACKGROUND: Clinical outcomes and treatment selection after completing the randomized phase of modern trials, investigating antiplatelet therapy (APT) after percutaneous coronary intervention (PCI), are unknown. OBJECTIVES: The authors sought to investigate cumulative 15-month and 12-to-15-month outcomes after PCI during routine care in the MASTER DAPT trial. METHODS: The MASTER DAPT trial randomized 4,579 high bleeding risk patients to abbreviated (n = 2,295) or standard (n = 2,284) APT regimens. Coprimary outcomes were net adverse clinical outcomes (NACE) (all-cause death, myocardial infarction, stroke, and BARC 3 or 5 bleeding); major adverse cardiac and cerebral events (MACCE) (all-cause death, myocardial infarction, and stroke); and BARC type 2, 3, or 5 bleeding. RESULTS: At 15 months, prior allocation to a standard APT regimen was associated with greater use of intensified APT; NACE and MACCE did not differ between abbreviated vs standard APT (HR: 0.92 [95% CI: 0.76-1.12]; P = 0.399 and HR: 0.94 [95% CI: 0.76-1.17]; P = 0.579; respectively), as during the routine care period (HR: 0.81 [95% CI: 0.50-1.30]; P = 0.387 and HR: 0.74 [95% CI: 0.43-1.26]; P = 0.268; respectively). BARC 2, 3, or 5 was lower with abbreviated APT at 15 months (HR: 0.68 [95% CI: 0.56-0.83]; P = 0.0001) and did not differ during the routine care period. The treatment effects during routine care were consistent with those observed within 12 months after PCI. CONCLUSIONS: At 15 months, NACE and MACCE did not differ in the 2 study groups, whereas the risk of major or clinically relevant nonmajor bleeding remained lower with abbreviated compared with standard APT. (Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated Versus Prolonged DAPT Regimen [MASTER DAPT]; NCT03023020).

Microvascular Resistance Reserve to Assess Microvascular Dysfunction in ANOCA Patients.

BACKGROUND: Microvascular resistance reserve (MRR) is a new index to assess coronary microvascular (dys)function, which can be easily measured invasively using continuous thermodilution. In contrast to coronary flow reserve (CFR), MRR is independent of epicardial coronary disease and hemodynamic variations. Its measurement is accurate, reproducible, and operator independent. OBJECTIVES: The aim of this study was to establish the range of normal values for MRR and to determine an optimal cutoff point. METHODS: In this exploratory study in 214 patients with angina and no obstructive coronary artery disease, after excluding significant epicardial disease, all physiological parameters, such as fractional flow reserve, index of microvascular resistance, CFR, absolute blood flow, absolute microvascular resistance, and MRR, were measured. On the basis of concordant positive or concordant negative results of index of microvascular resistance and CFR, subgroups of patients were defined with high probability of either normal (n = 122) or abnormal (n = 24) microcirculatory function, and MRR was studied in these groups. RESULTS: Mean MRR in the "normal" group was 3.4 compared with a mean MRR of 1.9 in the "abnormal" group; these values were significantly different between the groups. MRR >2.7 ruled out coronary microvascular dysfunction (CMD) with a certainty of 96%, whereas MRR <2.1 indicated the presence of CMD with a similar high certainty of 96%. CONCLUSIONS: MRR is a suitable index to distinguish the presence or absence of CMD in patients with angina and no obstructive coronary artery disease. The present data indicate that an MRR of 2.7 virtually excludes the presence of CMD, while an MRR value <2.1 confirms its presence.