5/17/2023 0 Comments Nadia kullo![]() ![]() Categorical variables are presented as counts (raw percentages) and differences compared using Pearson’s chi-square test or Fisher’s exact test if cell frequencies were not sufficient. Continuous variables are presented as medians (Q1, Q3) and differences compared using the Wilcoxon rank-sum test or Student’s t-test, as appropriate. Presence of LMD was defined as LMD stenosis ≥50%. We did not analyze cardiac magnetic resonance (CMR) data in relation to LMD due to the low number of patients enrolled after this stress test modality. For stress echocardiography, mild ischemia was defined as 70% stenosis of a major coronary artery on CCTA. For stress nuclear imaging (single-photon emission computed tomography or positron-emission tomography), mild ischemia was defined as reversible ischemia affecting 15% ischemia (summed difference score ≥10). The core laboratories independently interpreted baseline stress tests for all trial participants. Stress test data (e.g., images and ECG recordings for those undergoing ETT) were transferred electronically to the relevant core laboratory. Sites were directed to screen and enroll patients with moderate or severe ischemia, as determined locally on a stress test performed for clinical indications, preferably within the prior 3 months. Stress imaging and ETT eligibility criteria for the ISCHEMIA trial have been previously described.( 5) Stress testing details are mentioned in brief below. Figure 1 depicts how the study population was derived. Patients who had CCTA done before the study were also excluded. ![]() Patients with prior coronary artery bypass grafts (CABG) were excluded from this analysis. All participants provided informed consent.įor this analysis, enrolled ISCHEMIA participants with available CCTA interpretation for the presence or absence of LMD and available core laboratory interpretation of ischemia severity were analyzed. IRB approval was obtained at the Clinical Coordinating Center (NYU Grossman School of Medicine IRB) and at each coordinating center and site. ISCHEMIA was funded by the National Heart, Lung, and Blood Institute. Major exclusion criteria included estimated glomerular filtration rate (eGFR) less than 30mL/min/ 1.73m 2, myocardial infarction (MI) or unstable angina within 2 months of randomization, left ventricular ejection fraction less than 35%, LMD ≥50% on CCTA, New York Heart Association class III to IV heart failure or exacerbation of chronic heart failure within 6 months, or unacceptable angina despite maximally tolerated medical therapy.( 5) Enrolled patients that were not confirmed to be eligible for randomization after additional testing and core laboratory review were excluded from the trial. CCTA was performed to confirm the presence of obstructive CAD and to rule out LMD. Patients were eligible if they were clinically stable, including stable angina or silent ischemia. In brief, the ISCHEMIA cohort comprised patients with stable ischemic heart disease and moderate or severe ischemia on clinically indicated stress imaging or severe ischemia on exercise tolerance test (ETT) as determined by enrolling sites and read later at centralized trial core laboratories. The aim of this post hoc analysis of ISCHEMIA( 5) was to explore the markers of LMD using clinical and noninvasive functional parameters and to identify whether functional testing modalities can predict LMD on CCTA. Previous studies that evaluated clinical or functional tests (i.e, stress test) criteria for the identification of LMD are sparse and mostly performed in small populations.( 4) Hence, detection of LMD during the initial evaluation of patients with myocardial ischemia is important as revascularization remains the guideline-recommended management strategy in these patients. ![]() The ISCHEMIA trial, which randomized patients with moderate or severe ischemia to guideline-directed medical therapy vs guideline-directed medical therapy plus optimal revascularization, showed no statistical difference between the groups for the primary composite outcome or the secondary outcome of cardiovascular death or myocardial infarction.( 3) However, patients with LMD ≥50% on computed coronary tomographic angiography (CCTA) were excluded from randomization. Detection of significant (≥50%) left main disease (LMD) has major prognostic and therapeutic implications.( 1) While the detection of obstructive coronary artery disease (CAD) is important, this is especially true of LMD because current guidelines recommend revascularization to improve survival when LMD is present.( 2) ![]()
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