Citations

Abstract Background Coronary computed tomography angiography (CCTA) and myocardial perfusion imaging (MPI) are guideline-recommended to assist in clinical decision-making in patients with prior coronary artery bypass grafting (CABG). However, the value of combining CCTA and MPI for guiding revascularization decision-making in post-CABG patients with recurrent ischemic symptoms remains unexplored. In this study, we compared Heart Team strategies for revascularization based on CCTA and MPI as standalone and hybrid CCTA/MPI imaging, to strategies guided by invasive coronary angiography (ICA). Methods We included symptomatic patients with prior CABG who underwent CCTA and MPI (single-photon emission computed tomography, positron emission tomography or stress perfusion cardiac magnetic resonance imaging) preceding ICA. Simulated Heart Teams, blinded to other Heart teams and outcomes, performed revascularization decision-making based on conventional CCTA, MPI and a hybrid CCTA/MPI strategy (non-invasive Heart Team) or based on ICA (invasive Heart Team). The primary outcome was the Cohen’s kappa agreement (κ) between non-invasive and invasive Heart Teams. Results A total of 115 patients (mean age 73±7 years; 99 [86%] male) were included. Revascularization was recommended in 96 patients (83.5%) by CCTA, 92 patients (80.0%) by MPI, 80 patients (69.6%) by hybrid CCTA/MPI and 76 patients (66.1%) by ICA. The agreements were significant but low for CCTA (κ: 0.25 [95% confidence interval (CI): 0.07-0.42], P=0.003) and MPI (κ: 0.27 [95% CI: 0.09-0.48], P=0.002) compared to ICA, with only a modest increase when using the hybrid non-invasive imaging strategy (κ: 0.32 [95% CI: 0.14-0.51], P<0.001). Conclusions In patients with recurrent ischemic symptoms after CABG, Heart Team assessment of conventional CCTA and MPI yielded similarly poor agreements with revascularization strategies based on ICA, with only a modest improvement observed when using a hybrid CCTA/MPI approach. Overall, non-invasive imaging alone appears insufficient to accurately guide treatment strategies in patients with prior CABG, and their use as gatekeeping for ICA in these patients should be questioned.

ABSTRACT Background The relationship between height differences related to graft anatomy and physiological pressure indices in coronary bypass grafts has not been studied. We sought to study the impact of hydrostatic pressure on fractional flow reserve (FFR) in saphenous vein grafts (SVGs). Methods Included were 66 symptomatic patients (76 SVGs) with prior coronary artery bypass grafting who underwent coronary computed tomography angiography (CCTA) preceding invasive coronary angiography with FFR interrogation of ≥ 1 SVGs. The graft course and height excursion were reconstructed based on CCTA images. The impact of hydrostatic pressure on FFR (corrected FFR) was calculated by adding or subtracting 0.077 mmHg to the distal coronary pressure for every millimeter height difference in a supine position between the SVG ostium and the pressure wire tip position. Results The height difference (mm) between the SVG ostium and pressure wire tip position was largest for single SVGs to the circumflex artery (Cx; −55.1 ± 17.0), followed by sequential SVGs to the Cx (−51.8 ± 17.3) and the right coronary artery (RCA; −36.7 ± 21.6). The correlation between height difference and uncorrected FFR was −0.59 ( p < 0.001). Corrected FFR was lower as compared to uncorrected FFR in the overall cohort (0.86 ± 0.17 vs. 0.88 ± 0.18), in single SVGs to Cx (0.85 ± 0.17 vs. 0.90 ± 0.18), and in sequential SVGs to Cx (0.92 ± 0.14 vs. 0.96 ± 0.15) and RCA (0.82 ± 0.17 vs. 0.85 ± 0.21) ( p < 0.001 for all). Conclusions Hydrostatic pressure related to height differences along the course anatomy of SVGs can impact FFR measurements, with corrected FFR being significantly lower in SVGs to the Cx and sequential SVGs to the RCA.

Following the neutral results of the dal-OUTCOMES trial, a genome-wide study identified the rs1967309 variant in the adenylate cyclase type 9 ( ADCY9 ) gene on chromosome 16 as being associated with the risk of future cardiovascular events only in subjects taking dalcetrapib, a CETP (cholesterol ester transfer protein) modulator. Homozygotes for the minor A allele (AA) were protected from recurrent cardiovascular events when treated with dalcetrapib, while homozygotes for the major G allele (GG) had increased risk. Here, we present the current state of knowledge regarding the impact of rs1967309 in ADCY9 on clinical observations and biomarkers in dalcetrapib trials and the effects of mouse ADCY9 gene inactivation on cardiovascular physiology. Finally, we present our current model of the interaction between dalcetrapib and ADCY9 gene variants in the arterial wall macrophage, based on the intracellular role of CETP in the transfer of complex lipids from endoplasmic reticulum membranes to lipid droplets. Briefly, the concept is that dalcetrapib would inhibit CETP-mediated transfer of cholesteryl esters, resulting in a progressive inhibition of cholesteryl ester synthesis and free cholesterol accumulation in the endoplasmic reticulum. Reduced ADCY9 activity, by paradoxically leading to higher cyclic AMP levels and in turn increased cellular cholesterol efflux, could impart cardiovascular protection in rs1967309 AA patients. The ongoing dal-GenE trial recruited 6145 patients with the protective AA genotype and will provide a definitive answer to whether dalcetrapib will be protective in this population.

Background and Purpose: Periventricular white matter hyperintensities (WMH; PVWMH) and deep WMH (DWMH) are regional classifications of WMH and reflect proposed differences in cause. In the first study, to date, we undertook genome-wide association analyses of DWMH and PVWMH to show that these phenotypes have different genetic underpinnings. Methods: Participants were aged 45 years and older, free of stroke and dementia. We conducted genome-wide association analyses of PVWMH and DWMH in 26,654 participants from CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology), ENIGMA (Enhancing Neuro-Imaging Genetics Through Meta-Analysis), and the UKB (UK Biobank). Regional correlations were investigated using the genome-wide association analyses -pairwise method. Cross-trait genetic correlations between PVWMH, DWMH, stroke, and dementia were estimated using LDSC. Results: In the discovery and replication analysis, for PVWMH only, we found associations on chromosomes 2 ( NBEAL ), 10q23.1 ( TSPAN14/FAM231A ), and 10q24.33 ( SH3PXD2A). In the much larger combined meta-analysis of all cohorts, we identified ten significant regions for PVWMH: chromosomes 2 (3 regions), 6, 7, 10 (2 regions), 13, 16, and 17q23.1. New loci of interest include 7q36.1 ( NOS3 ) and 16q24.2. In both the discovery/replication and combined analysis, we found genome-wide significant associations for the 17q25.1 locus for both DWMH and PVWMH. Using gene-based association analysis, 19 genes across all regions were identified for PVWMH only, including the new genes: CALCRL (2q32.1), KLHL24 (3q27.1), VCAN (5q27.1), and POLR2F (22q13.1). Thirteen genes in the 17q25.1 locus were significant for both phenotypes. More extensive genetic correlations were observed for PVWMH with small vessel ischemic stroke. There were no associations with dementia for either phenotype. Conclusions: Our study confirms these phenotypes have distinct and also shared genetic architectures. Genetic analyses indicated PVWMH was more associated with ischemic stroke whilst DWMH loci were implicated in vascular, astrocyte, and neuronal function. Our study confirms these phenotypes are distinct neuroimaging classifications and identifies new candidate genes associated with PVWMH only.