Quantitative flow ratio (QFR) identifies functional relevance of non-culprit lesions in coronary angiographies of patients with acute myocardial infarction

Introduction In patients with acute myocardial infarction (AMI) and multivessel coronary disease, revascularization of non-culprit lesions guided by proof of ischemia usually requires staged ischemia testing. Quantitative flow ratio (QFR) has been shown to be effective in assessing the hemodynamic relevance of lesions in stable coronary disease. However, its suitability in AMI patients is unknown. In this study, we tested the diagnostic value of QFR based on acute angiograms (aQFR) during AMI to assess the hemodynamic relevance of non-culprit lesions. Methods We retrospectively assessed the diagnostic efficiency of aQFR in 280 vessels from 220 patients, comparing it with staged ischemia testing using elective coronary angiography with FFR (n = 47), stress cardiac MRI (n = 200) or SPECT (n = 33). Results aQFR showed a very good diagnostic efficiency (AUC = 0.887, 95% CI 0.832–0.943, p < 0.001) in predicting ischemia of non-culprit lesions, significantly superior to coronary lesion’s geometry as assessed by quantitative coronary angiography. The optimal cut-off for aQFR to predict ischemia was 0.80 (sensitivity = 83.7%, specificity = 86.1%). Maintaining a predefined level of 95% sensitivity and specificity, we created a decision model based on aQFR: lesions with aQFR ≤ 0.75 should be treated, lesions with aQFR ≥ 0.92 do not yield any hemodynamic relevance, and lesions in the “grey zone” (aQFR 0.75–0.92) benefit from further ischemia testings. This model would allow to reduce staged ischemia tests by 46.8% without a relevant loss in diagnostic efficiency. Conclusion Our data demonstrate that aQFR allows an effective assessment of hemodynamic relevance of non-culprit lesions in AMI and may guide interventions of non-culprit coronary lesions. Graphic abstract

Abstract 14527: Utility of Routine Invasive Coronary Angiography Prior to Transcatheter Aortic Valve Replacement

Introduction: Despite the high prevalence of CAD in patients with severe aortic stenosis (AS), the optimal management of concomitant coronary artery disease (CAD) before trasncatheter aortic valve replacement (TAVR) remains controversial. Hypothesis: To characterize the contemporary, real-world burden of CAD in contemporary TAVR patients and to evaluate revascularization practices at a high-volume center in the United States. Methods: Analysis of all adult patients referred for TAVR at our center between January 2019 and January 2020. Presence of significant coronary artery disease (stenosis >50%) and subsequent management (medical therapy versus revascularization) were recorded. Presenting symptoms, use of non-invasive and invasive ischemia testing and pre-TAVR computed tomography (CT) imaging were all analyzed. Results: A total of 394 patients with severe AS were referred to our institution for TAVR. Thirty-nine patients (9.9%) instead underwent surgical aortic valve replacement (SAVR), of which only 5 (1.3%) underwent SAVR plus coronary artery bypass surgery. Of the remaining 355 patients (77.3 ± 9.3 years old and 59.7% males), 218 patients (61.4%) had insignificant CAD. Of the 137 patients (38.6%) with significant CAD, only 30 (8.5%) underwent percutaneous coronary intervention (PCI). Of these, less than half had anginal symptoms, a third had CAD in proximal segments and a third underwent ischemia testing prior to PCI. Pre-TAVR CT accurately identified significant CAD in 28/30 patients (93.3%) who ultimately underwent PCI. Conclusions: Only 1 in 25 contemporary TAVR patients had significant CAD and anginal symptoms requiring intervention, questioning the utility of routine invasive coronary angiography before TAVR. A Heart Team approach integrating anginal symptoms and ischemia testing is needed to guide the need, timing and strategy of revascularization. The pre-TAVR CT images could identify significant proximal segment CAD needing PCI.

Will Resting Full-Cycle Ratio Substitute Fractional Flow Reserve

Physiological assessment of coronary artery stenosis added an element of certainty of benefit to the patient undergoing revascularization. Fractional flow reserve (FFR) was the gold standard, with good reproducibility, correlation with noninvasive inducible ischemia testing and, most importantly, clinical benefit. Increased usage also brought into focus some limitations with respect to achieving hyperemia, assessment of sequential stenoses, drift, multivessel disease, chronic total occlusion, fidelity and accuracy of measurement and, in some cases, cost of adenosine. This set the background for nonhyperemic testing which eliminates the need for drug administration and simplifies procedure vastly.

Identifying stroke therapeutics from preclinical models: A protocol for a novel application of network meta-analysis

Introduction: Globally, stroke is the second leading cause of death. Despite the burden of illness and death, few acute interventions are available to patients with ischemic stroke. Over 1,000 potential neuroprotective therapeutics have been evaluated in preclinical models. It is important to use robust evidence synthesis methods to appropriately assess which therapies should be translated to the clinical setting for evaluation in human studies. This protocol details planned methods to conduct a systematic review to identify and appraise eligible studies and to use a network meta-analysis to synthesize available evidence to answer the following questions: in preclinical in vivo models of focal ischemic stroke, what are the relative benefits of competing therapies tested in combination with the gold standard treatment alteplase in (i) reducing cerebral infarction size, and (ii) improving neurobehavioural outcomes? Methods: We will search Ovid Medline and Embase for articles on the effects of combination therapies with alteplase. Controlled comparison studies of preclinical in vivo models of experimentally induced focal ischemia testing the efficacy of therapies with alteplase versus alteplase alone will be identified. Outcomes to be extracted include infarct size (primary outcome) and neurobehavioural measures. Risk of bias and construct validity will be assessed using tools appropriate for preclinical studies. Here we describe steps undertaken to perform preclinical network meta-analysis to synthesise all evidence for each outcome and obtain a comprehensive ranking of all treatments. This will be a novel use of this evidence synthesis approach in stroke medicine to assess pre-clinical therapeutics. Combining all evidence to simultaneously compare mutliple therapuetics tested preclinically may provide a rationale for the clinical translation of therapeutics for patients with ischemic stroke. Dissemination: Review findings will be submitted to a peer-reviewed journal and presented at relevant scientific meetings to promote knowledge transfer. Registration: PROSPERO number to be submitted following peer review.