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Key Points Question What proportion of patients with left ventricular dysfunction identified during hospitalization for acute myocardial infarction have follow-up assessment of left ventricular ejection fraction (LVEF)? Findings In this cohort study of 501 patients, 303 patients had undergone LVEF reassessment by 6 months, with significant variability according to patient-level and site-level characteristics. Meaning These findings suggest that programs to improve the quality of post–myocardial infarction care should include measures to ensure that indicated repeat cardiac imaging is performed., This cohort study assesses adherence with guideline-recommended left ventricular ejection fraction (LVEF) reassessment after myocardial infarction and studies the evolution of LVEF over 6 months of follow-up in the Acute Myocardial Infarction Quality Assurance (AMIQA) Canada study., Importance Persistently depressed left ventricular ejection fraction (LVEF) after myocardial infarction (MI) is associated with adverse prognosis and directs the use of evidence-based treatments to prevent sudden cardiac death and/or progressive heart failure. Objective To assess adherence with guideline-recommended LVEF reassessment and to study the evolution of LVEF over 6 months of follow-up. Design, Setting, and Participants This was a multicenter cohort study at Canadian academic and community hospitals with on-site cardiac catheterization services. Patients with type 1 acute MI and LVEF less than or equal to 45% during the index hospitalization were enrolled between January 2018 and August 2019 and were followed-up for 6 months. Data analysis was performed from May 2020 to September 2021. Exposures Baseline clinical factors, in-hospital care and LVEF, and site-specific features. Main Outcomes and Measures The main outcomes were receipt of repeat LVEF assessment by 6 months and the presence of a persistent LVEF reduction at 2 thresholds: LVEF less than or equal to 40%, prompting consideration of additional medical therapy for heart failure, or LVEF less than or equal to 35%, prompting referral for implanted cardioverter defibrillator in addition to medical therapy. Results This study included 501 patients (mean [SD] age, 63.3 [13.0] years; 113 women [22.6%]). Overall, 370 patients (73.4%) presented with STEMI, and 454 (90.6%) had in-hospital revascularization. The median (IQR) baseline LVEF was 40% (34%-43%). Of 458 patients (91.4%) who completed the 6-month follow-up, 303 (66.2%; 95% CI, 61.7%-70.5%) had LVEF reassessment, with a range of 46.7% to 90.0% across sites (χ213 = 19.6; P = .11). Participants from community hospitals were more likely than those from academic hospitals to undergo LVEF reassessment (73.6% vs 63.2%; χ21 = 4.50; P = .03), as were those with worse LVEF at baseline. Follow-up LVEF improved by an absolute median (IQR) of 8% (3%-15%). However, 103 patients (34.1%) met the definitions of clinically relevant LVEF reduction, including 52 patients (17.2%) with LVEF less than or equal to 35% and 51 patients (16.9%) with LVEF of 35.1% to 40.0%. Conclusions and Relevance In this cohort study, approximately 1 in 3 patients with at least mild LVEF reduction after acute MI did not undergo indicated LVEF reassessment within 6 months, suggesting that programs to improve the quality of post-MI care should include measures to ensure that indicated repeat cardiac imaging is performed. In those with follow-up imaging, clinically relevant persistent LVEF reduction was identified in more than one-third of patients.

The clinical value of ischemic conditioning during percutaneous coronary intervention (PCI) and mode of administration is controversial. Our aim was to assess the long-term effect of remote ischemic postconditioning among patients undergoing PCI. We randomized 360 patients undergoing PCI who presented with a negative troponin T at baseline into 3 groups: 2 groups received remote ischemic postconditioning (with ischemia applied to the arm in 1 group and to the thigh in the other group), and the third group acted as a control group. Remote ischemic postconditioning was applied during PCI immediately following stent deployment, by 3, 5-minute cycles of blood pressure cuff inflation to >200 mm Hg on the arm or thigh (20 mm Hg to the arm in the control), with 5-minute breaks between each cycle. There were no differences in baseline characteristics among the 3 groups. Periprocedural myocardial injury occurred in 33% (P = 0.64). After 1 year, there was no difference between groups in death (P = 0.91), myocardial infarction (P = 0.78), or repeat revascularization (P = 0.86). During 3 years of follow-up, there was no difference in death, myocardial infarction, and revascularization among the groups (P = 0.45). Remote ischemic postconditioning during PCI did not affect long-term cardiovascular outcome. A similar effect was obtained when remote ischemia was induced to the upper or lower limb. ClinicalTrials.gov Identifier: NCT00970827.

The duration of red blood cell (RBC) storage may have a negative impact on endothelial nitric oxide bioavailability. We tested the hypothesis that transfused fresh blood will have a more favorable effect on microvascular endothelial function as compared to older standard issue blood.Participants requiring chronic RBC transfusions were enrolled in a crossover design study to receive fresh (7 days of storage) or standard (up to 42 days of storage) blood on 2 separate visits. Endothelial function was assessed by reactive hyperemia peripheral arterial tonometry that was measured before and after transfusions. For each participant, the difference between endothelial function pretransfusion and posttransfusion was assessed in relation to blood storage time.Twenty-one patients (71 ± 16 years, 52% females) were enrolled. Mean age of fresh blood was 5.5 days (±1.0), and that of standard blood was 24.5 days (±7.9 days). The pretransfusion hemoglobin was 83.1 ± 2.5 g/L; and posttransfusion, 98.9 ± 2.6 g/L. An average of 2 U of packed RBCs was transfused. Microvascular endothelial function decreased more frequently after transfusion of standard blood compared to fresh blood. Standard issue blood transfusion was associated with decrease in reactive hyperemia peripheral arterial tonometry index (-0.25 ± 0.63) compared to fresh blood (+0.03 ± 0.49); P = .026.Transfusions of standard issue blood are associated with less favorable effect on microvascular endothelial function as compared to fresh blood.

Ticagrelor has shown superiority compared with clopidogrel in reducing cardiovascular events [(1)][1]. Although some of the clinical benefits of ticagrelor may simply reflect its potency in inhibiting platelet aggregation, the action of this drug on blood vessels may also play a role. Ticagrelor

This clinical trial assesses ticagrelor administration and endothelial function and arterial stiffness in patients with coronary artery disease.

Background Radial artery occlusion is a known complication following transradial cardiac catheterization. A shorter duration of postprocedural radial clamp time may reduce radial artery occlusion ( RAO ) but might be associated with incomplete hemostasis. Methods and Results In total, 568 patients undergoing transradial diagnostic cardiac catheterization were randomly assigned to either 20 minutes (ultrashort) or 60 minutes (short) hemostatic compression time using patent hemostasis. Subsequently, clamp pressure was reduced gradually over 20 minutes. Access site hemostasis and RAO were assessed after clamp removal. Repeated assessment of RAO was determined at 1 week in 210 (37%) patients. Mean age was 64±11 years, and 30% were female. Percutaneous coronary intervention was performed in 161 patients. RAO immediately after clamp removal was documented in 14 (4.9%) and 8 (2.8%) patients in the 20‐ and 60‐minute clamp application groups, respectively ( P =0.19). The incidence of grade 1 hematoma was higher in the 20‐minute group (6.7% versus 2.5%, P =0.015). RAO at 1 week after the procedure was 2.9% and 0.9% in the 20‐ and 60‐minute groups, respectively ( P =0.36). Requirement for clamp retightening (36% versus 16%, P =0.01) was higher among patients who had RAO . Need for clamp retightening was the only independent predictor of RAO ( P =0.04). Conclusions Ultrashort radial clamp application of 20 minutes is not preferable to a short duration of 60 minutes. The 60‐minute clamp duration is safe and provides good access site hemostasis with low RAO rates. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 02269722.

Background Coronary no-reflow during primary percutaneous coronary intervention (PPCI) is a predictor of poorer cardiovascular outcome. Both endothelial dysfunction and no-reflow involves abnormal vascular function and hemostasis. Our aim was to assess the association between endothelial dysfunction and no reflow during primary PCI. Methods Thirty consecutive patients with ST elevation myocardial infarction (STEMI) and normal flow during primary PCI were compared to 19 consecutive patients who had no reflow. All subjects underwent assessment of peripheral endothelial function by reactive hyperemia index (RHI) 48–72 h post PCI using the EndoPAT device. Results Age, sex and hypertension were similar in both groups. Smokers were less likely to have no-reflow. Post PPCI there was less ST segment resolution in the no-reflow group (48% ± 7 vs. 81% ± 6; p = 0.001). Patients who had no reflow had subsequently lower ejection fraction (39% ± 10 vs. 47% ± 10; p = 0.015). There was no difference in vascular function (RHI), between the no-reflow and normal flow groups (1.91 ± 0.3 vs. 2.09 ± 0.11; p = 0.24). Conclusions Systemic peripheral endothelial function does not differ between STEMI patients with and without no reflow during primary PCI.

The geko™ device is a small transcutaneous nerve stimulator that is applied non-invasively to the skin over the common peroneal nerve to stimulate peripheral blood flow. The purpose of this study was to investigate the effect of peripheral nerve stimulation on coronary flow dynamics and systemic endothelial function. We enrolled 10 male patients, age 59 ± 11 years, with symptomatic obstructive coronary disease undergoing percutaneous coronary intervention (PCI). Coronary flow dynamics were assessed invasively using Doppler flow wire at baseline and with nerve stimulation for 4 min. Measurements were taken in the stenotic coronary artery and in a control vessel without obstructive disease. At a separate visit, peripheral blood flow at the popliteal artery (using duplex ultrasound assessment) and endothelial function assessed by peripheral artery tonometry (PAT) were measured at baseline and after one hour of nerve stimulation. Compared to baseline, there was a significant increase in coronary blood flow as measured by average peak velocity (APV) in the control vessel with nerve stimulation (20.3 ± 7.7 to 23.5 ± 10 cm/s; p = 0.03) and non-significant increase in the stenotic vessel (21.9 ± 12 to 23.9 ± 12.9 cm/s; p = 0.23). Coronary flow reserve did not change significantly. Reactive hyperemia-peripheral arterial tonometry (Rh-PAT) increased from 2.28 ± 0.39 to 2.67 ± 0.6, p = 0.045. A few minutes of peripheral nerve stimulation may improve coronary blood flow. This effect is more prominent in non-stenotic vessels. Longer stimulation improved endothelial function.

• By improving venous return, gekoTM has the potential to have a therapeutic effect in the management of coronary artery disease by augmenting coronary blood flow Background: Improving myocardial blood supply in patients with coronary artery disease (CAD) may improve angina. The gekoTM device is a small transcutaneous nerve stimulator that is applied non-invasively to the skin over the common peroneal nerve and stimulates peripheral blood flow. The purpose of this study was to investigate the effect of the gekoTM device on coronary blood flow.