BACKGROUNDIschemic heart disease is a major cause of out-of-hospital cardiac arrest. The role of immediate coronary angiography and percutaneous coronary intervention (PCI) in the treatment of patients who have been successfully resuscitated after cardiac arrest in the absence of ST-segment elevation myocardial infarction (STEMI) remains uncertain. METHODSIn this multicenter trial, we randomly assigned 552 patients who had cardiac arrest without signs of STEMI to undergo immediate coronary angiography or coronary angiography that was delayed until after neurologic recovery. All patients underwent PCI if indicated. The primary end point was survival at 90 days. Secondary end points included survival at 90 days with good cerebral performance or mild or moderate disability, myocardial injury, duration of catecholamine support, markers of shock, recurrence of ventricular tachycardia, duration of mechanical ventilation, major bleeding, occurrence of acute kidney injury, need for renal-replacement therapy, time to target temperature, and neurologic status at discharge from the intensive care unit. RESULTSAt 90 days, 176 of 273 patients (64.5%) in the immediate angiography group and 178 of 265 patients (67.2%) in the delayed angiography group were alive (odds ratio, 0.89; 95% confidence interval [CI], 0.62 to 1.27; P = 0.51). The median time to target temperature was 5.4 hours in the immediate angiography group and 4.7 hours in the delayed angiography group (ratio of geometric means, 1.19; 95% CI, 1.04 to 1.36). No significant differences between the groups were found in the remaining secondary end points. CONCLUSIONSAmong patients who had been successfully resuscitated after out-of-hospital cardiac arrest and had no signs of STEMI, a strategy of immediate angiography was not found to be better than a strategy of delayed angiography with respect to overall survival at 90 days. (Funded by the Netherlands Heart Institute and others; COACT Netherlands Trial Register number, NTR4973.

IMPORTANCE Ischemic heart disease is a common cause of cardiac arrest. However, randomized data on long-term clinical outcomes of immediate coronary angiography and percutaneous coronary intervention (PCI) in patients successfully resuscitated from cardiac arrest in the absence of ST segment elevation myocardial infarction (STEMI) are lacking.OBJECTIVE To determine whether immediate coronary angiography improves clinical outcomes at 1 year in patients after cardiac arrest without signs of STEMI, compared with a delayed coronary angiography strategy. DESIGN, SETTING, AND PARTICIPANTSA prespecified analysis of a multicenter, open-label, randomized clinical trial evaluated 552 patients who were enrolled in 19 Dutch centers between January 8, 2015, and July 17, 2018. The study included patients who experienced out-of-hospital cardiac arrest with a shockable rhythm who were successfully resuscitated without signs of STEMI. Follow-up was performed at 1 year. Data were analyzed, using the intention-to-treat principle, between August 29 and October 10, 2019.INTERVENTIONS Immediate coronary angiography and PCI if indicated or coronary angiography and PCI if indicated, delayed until after neurologic recovery.MAIN OUTCOMES AND MEASURES Survival, myocardial infarction, revascularization, implantable cardiac defibrillator shock, quality of life, hospitalization for heart failure, and the composite of death or myocardial infarction or revascularization after 1 year.RESULTS At 1 year, data on 522 of 552 patients (94.6%) were available for analysis. Of these patients, 413 were men (79.1%); mean (SD) age was 65.4 (12.3) years. A total of 162 of 264 patients (61.4%) in the immediate angiography group and 165 of 258 patients (64.0%) in the delayed angiography group were alive (odds ratio, 0.90; 95% CI, 0.63-1.28). The composite end point of death, myocardial infarction, or repeated revascularization since the index hospitalization was met in 112 patients (42.9%) in the immediate group and 104 patients (40.6%) in the delayed group (odds ratio, 1.10; 95% CI, 0.77-1.56). No significant differences between the groups were observed for the other outcomes at 1-year follow-up. For example, the rate of ICD shocks was 20.4% in the immediate group and 16.2% in the delayed group (odds ratio, 1.32; 95% CI, 0.66-2.64). CONCLUSIONS AND RELEVANCEIn this trial of patients successfully resuscitated after out-of-hospital cardiac arrest and without signs of STEMI, a strategy of immediate angiography was not found to be superior to a strategy of delayed angiography with respect to clinical outcomes at 1 year. Coronary angiography in this patient group can therefore be delayed until after neurologic recovery without affecting outcomes. TRIAL REGISTRATION trialregister.nl Identifier: NTR4973

CMD decreases the diagnostic performance of QFR. However, even in the presence of CMD, QFR remains superior to angiography alone in ascertaining functional stenosis severity.

IMPORTANCE Percutaneous coronary intervention (PCI) of nonculprit vessels among patients with ST-segment elevation myocardial infarction (STEMI) is associated with improved clinical outcome compared with culprit vessel-only PCI. Fractional flow reserve (FFR) and coronary flow reserve are hyperemic indices used to guide revascularization. Recently, instantaneous wave-free ratio was introduced as a nonhyperemic alternative to FFR. Whether these indices can be used in the acute setting of STEMI continues to be investigated. OBJECTIVE To assess the value of hemodynamic indices in nonculprit vessels of patients with STEMI from the index event to 1-month follow-up. DESIGN, SETTING, AND PARTICIPANTS This substudy of the Reducing Micro Vascular Dysfunction in Revascularized STEMI Patients by Off-target Properties of Ticagrelor (REDUCE-MVI) randomized clinical trial enrolled 98 patients with STEMI who had an angiographic intermediate stenosis in at least 1 nonculprit vessel. Patient enrollment was between May 1, 2015, and September 19, 2017.After successful primary PCI, nonculprit intracoronary hemodynamic measurements were performed and repeated at 1-month follow-up. Cardiac magnetic resonance imaging was performed from 2 to 7 days and 1 month after primary PCI. MAIN OUTCOMES AND MEASURESThe value of nonculprit instantaneous wave-free ratio, FFR, coronary flow reserve, hyperemic index of microcirculatory resistance, and resting microcirculatory resistance from the index event to 1-month follow-up. RESULTSOf 73 patients with STEMI included in the final analysis, 59 (80.8%) were male, with a mean (SD) age of 60.8 (9.9) years. Instantaneous wave-free ratio (SD) did not change significantly (0.93 [0.07] vs 0.94 [0.06]; P = .12) and there was no change in resting distal pressure/aortic pressure (mean [SD], 0.94 [0.06] vs 0.95 [0.06]; P = .25) from the acute moment to 1-month follow-up. The FFR decreased (mean [SD], 0.88 [0.07] vs 0.86 [0.09]; P = .001) whereas coronary flow reserve increased (mean [SD], 2.9 [1.4] vs 4.1 [2.2]; P < .001). Hyperemic index of microcirculatory resistance decreased and resting microcirculatory resistance increased from the acute moment to follow-up. The decrease in distal pressure from rest to hyperemia was smaller at the acute moment vs follow-up (mean [SD], 10.6 [11.2] mm Hg vs 14.1 [14.2] mm Hg; P = .05). This blunted acute hyperemic response correlated with final infarct size (ρ, -0.29; P = .02). The resistive reserve ratio was lower at the acute moment vs follow-up (mean [SD], 3.4 [1.7] vs 5.0 [2.7]; P < .001). CONCLUSIONS AND RELEVANCEIn the acute setting of STEMI, nonculprit coronary flow reserve was reduced and FFR was augmented, whereas instantaneous wave-free ratio was not altered. These results may be explained by an increased hyperemic microvascular resistance and a blunted adenosine responsiveness at the acute moment that was associated with infarct size.

Objectives We evaluated the diagnostic performance of quantitative flow ratio (QFR) assessment of nonculprit lesions (NCLs) based on acute setting angiograms obtained in patients with ST‐segment elevation myocardial infarction (STEMI) with QFR, fractional flow reserve (FFR), and instantaneous wave‐free ratio (iFR) in the staged setting as reference. Background QFR is an angiography‐based approach for the functional evaluation of coronary artery lesions. Methods This was a post‐hoc analysis of the iSTEMI study. NCLs were assessed with iFR in the acute setting and with iFR and FFR at staged (median 13 days) follow‐up. Acute and staged QFR values were computed in a core laboratory based on the coronary angiography recordings. Diagnostic cut‐off values were ≤0.80 for QFR and FFR, and ≤0.89 for iFR. Results Staged iFR and FFR data were available for 146 NCLs in 112 patients in the iSTEMI study. Among these, QFR analysis was feasible in 103 (71%) lesions assessed in the acute setting with a mean QFR value of 0.82 (IQR: 0.73–0.91). Staged QFR, FFR, and iFR were 0.80 (IQR: 0.70–0.90), 0.81 (IQR: 0.71–0.88), and 0.91 (IQR: 0.87–0.96), respectively. Classification agreement of acute and staged QFR was 93% (95%Cl: 87–99). The classification agreement of acute QFR was 84% (95%CI: 76–90) using staged FFR as reference and 74% (95%CI: 65–83) using staged iFR as reference. Conclusions Acute QFR showed a very good diagnostic performance with staged QFR as reference, a good diagnostic performance with staged FFR as reference, and a moderate diagnostic performance with staged iFR as reference.

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In this unique cohort, high serum leucocytes and high diastolic blood pressure are associated with poorly developed collaterals. Interestingly, the use of β blockers is associated with well-developed collaterals, shedding new light on the potential action mode of this drug in patients with CAD.

BackgroundQuantitative flow ratio (QFR), a novel functional angiography technique, computes fractional flow reserve (FFR) without pressure wires or adenosine. We investigated interindividual variations in the adenosine‐induced hemodynamics during FFR assessment and their influence on QFR diagnostic performance.Methods and ResultsPatients with coronary stenoses who underwent intracoronary pressure and flow assessment were analyzed. Adenosine‐induced hemodynamics during FFR measurement were determined by the percentage change in mean aortic pressure (%ΔPa) and the resistive reserve ratio (RRR). The diagnostic performance of QFR was evaluated and compared in each tertile of %ΔPa and RRR using FFR as reference. A total of 294 vessels (245 patients) were analyzed. Mean FFR was 0.80±0.11. Individuals showed a wide variation in the adenosine response in terms of %ΔPa (ranging from −75% to 43%; median, −9% [interquartile range, −3% to −17%]) and the RRR (ranging from 0.45 to 20.15; median, 3.1 [interquartile range, 2.1–4.9]). No significant differences for diagnostic efficiency of QFR were found between tertiles of %ΔPa (area under the curve for the receiver‐operating characteristic analysis, 0.950 in tertile 1, 0.929 in tertile 2, and 0.910 in tertile 3; P=0.270) or between tertiles of the RRR (area under the curve for the receiver‐operating characteristic analysis, 0.909 in tertile 1, 0.923 in tertile 2, and 0.959 in tertile 3; P=0.167). The classification agreement between QFR and FFR was not significantly modified by %ΔPa (tertile 1, 89%; tertile 2, 87%; and tertile 3, 86%; P=0.827) or by the RRR (tertile 1, 86%; tertile 2, 85%; and tertile 3, 91%; P=0.398).ConclusionsPatients undergoing FFR assessment show large interindividual variations in the magnitude of adenosine‐induced hemodynamics. However, such variations do not affect the diagnostic performance of QFR in assessing the functional relevance of observed stenoses.