Goldman, Steven

Background: The progression of CHF after MI has been traditionally evaluated by serial changes in EF. However, mechanical parameters can provide a greater insight into cardiac function. Wall strain measures myocardial deformation, and reflects contractile function as a percentage change in length. Wall stress represents the force per unit area on the myocardium, as an evaluation of LV afterload. The relationship between wall stress and wall strain is termed Young’s modulus, and it represents cardiac elasticity. This study leverages in-vivo Young’s modulus analysis derived from cardiac MRI, which has the potential to quantify the extent of myocardial remodeling, and aid in early detection of heart failure progression. Hypothesis: We hypothesize that Young’s modulus offers a more detailed assessment of regional wall motion abnormality than conventional imaging measures alone. Methods: Male Yucatan mini-swine underwent 90-minute balloon occlusion-reperfusion of the left anterior descending coronary artery to induce MI (N=13). Cardiac MRIs were obtained at baseline and 1-month post-MI. Cardiac wall stress and wall strain were calculated separately in the anteroseptal (infarcted) and inferolateral (non-infarcted) regions, and in the longitudinal and circumferential fiber orientations. These measurements were correlated to determine the Young’s modulus of the LV. Results: Anteroseptal and inferolateral longitudinal Young’s modulus increased from 28.01±8.14 to 67.14±15.08 kPa (p < 0.05) from 13.88±1.92 to 38.80±7.29 kPa (p < 0.001), respectively. Anteroseptal and inferolateral circumferential Young’s modulus increased from 34.61±10.33 to 119.17±30.94 kPa (p < 0.05) and from 16.77±1.32 to 58.76±18.98 kPa (p < 0.001), respectively. The regional changes were accompanied by a decrease in EF from 60.6±1.5 to 50.9±3.3% (p < 0.01). Discussion: Our findings show that Young’s modulus is a valuable parameter in quantifying regional changes that occur with LV systolic dysfunction after ischemic insult; specifically that regional abnormalities occur in the non-infarcted area as well as the infarcted area––a change that would not be picked up by global LV EF. Thus, quantifying regional and directional cardiac elasticity non-invasively is a novel parameter that warrants further study. Prior research has explored the in-vitro characteristics of cardiac elasticity, but there is limited research that details the in-vivo changes within any disease affecting myocardial fiber contractility.

Background: Direct stenting without pre-dilation or post-dilation has been advocated for saphenous vein graft percutaneous coronary intervention to decrease the incidence of distal embolization, periprocedural myocardial infarction, and target lesion revascularization. Methods: We performed a post hoc analysis of patients enrolled in the DIVA (Drug-Eluting Stents Versus Bare Metal Stents in Saphenous Vein Graft Angioplasty; NCT 01121224) prospective, double-blind, randomized controlled trial. Patients were stratified into stent-only and balloon-stent groups. Primary end point was 12-month incidence of target vessel failure (defined as the composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization). Secondary end points included all-cause death, stent thrombosis, myocardial infarction, and target lesion revascularization during follow-up. Results: Of the 575 patients included in this substudy, 185 (32%) patients underwent stent-only percutaneous coronary intervention. Patients in the stent-only versus balloon-stent group had similar baseline characteristics and similar incidence of target vessel failure at 12-months (15% versus 19%; hazard ratio, 1.34 [95% CI, 0.86–2.08]; P =0.19). During long-term follow-up (median of 2.7 years), the incidence of definite stent thrombosis (1% versus 5%; hazard ratio, 9.20 [95% CI, 1.23–68.92]; P =0.0085), the composite of definite or probable stent thrombosis (5% versus 11%; hazard ratio, 2.52 [95% CI, 1.23–5.18]; P =0.009), and target vessel myocardial infarction (8% versus 14%; hazard ratio, 1.92 [95% CI, 1.08–3.40]; P =0.023) was lower in the stent-only group. Multivariable analysis showed that a higher number of years since coronary artery bypass grafting and >1 target saphenous vein graft lesions were associated with increased target vessel failure during entire follow-up, while preintervention Thrombolysis in Myocardial Infarction-3 flow was protective. Conclusions: In patients undergoing percutaneous coronary intervention of de novo saphenous vein graft lesions, there was no difference in target vessel failure at 12 months and long-term follow-up in the stent-only versus the balloon-stent group; however, the incidence of stent thrombosis was lower in the stent-only group, as was target vessel myocardial infarction. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT 01121224.

VA Cooperative Studies Program #571 (DIVA) was designed to evaluate the efficacy of drug‐eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure when compared with bare‐metal stents (BMS) in participants undergoing stenting of de novo SVG lesions. Participants undergoing clinically indicated stenting of de novo SVG lesions were randomized in a 1:1 ratio to DES or BMS. Randomization was stratified by presence/absence of diabetes mellitus and the number of target SVG lesions (1 vs ≥2) within each participating site. At sites that did not routinely administer 12‐months of dual antiplatelet therapy after SVG stenting participants without acute coronary syndromes received 1 month of open‐label clopidogrel, followed by 11 months of clopidogrel for those assigned to DES and 11 months of placebo for those assigned to BMS. The primary endpoint was the 12‐month incidence of target‐vessel failure (defined as the composite of cardiac death, target‐vessel myocardial infarction, or target‐vessel revascularization). Secondary endpoints included the incidence of other clinical endpoints and the incremental cost‐effectiveness of DES relative to BMS. Due to lower‐than‐anticipated target‐vessel failure rates, target enrollment was increased from 519 to 762. The study had randomized 599 participants when recruitment ended in December 2015. The DIVA trial will provide clarity on the appropriate stent type for de novo SVG lesions.