CRT-D non-responders have worse cardiovascular outcome than patients after primary ICD implantation with similar baseline left ventricular ejection fraction

Background

Cardiac resynchronisation therapy (CRT) fails to improve echocardiographic parameters and outcome in 20–40% of heart failure (HF) patients with reduced ejection fraction (EF) referred to as CRT non-responders (CRT-NR). The aim of this study was to compare the outcomes of CRT-NR patients who received a CRT defibrillator (CRT-D) device with patients after primary implantable cardioverter-defibrillator (ICD) implantation for impaired left ventricular (LV) function.

Methods

CRT-NR status was defined as no or less than 10% improvement in LV EF 12 months post implantation. CRT-NR patients and those after primary ICD implantation for LV EF<35% were identified in our database between 2010 and 2019. CRT-NR patients were further categorized as progressors (decrease in LV EF ≥5%) or non-progressors (LV EF change between +9 to −5%). Primary endpoint was all-cause mortality or the need for heart transplantation during follow-up. Statistical significance was assessed by Log-rank test of Kaplan-Meier survival analysis.

Results

151 CRT-NR patients and 219 patients after primary ICD implantation were identified with a mean ± SEM follow-up of 43.7±2.5 and 47.3±2.2 months, respectively. Baseline (preoperative) LV EFs were higher (p<0.05) for the overall CRT-NR group (EF = 27.4±0.4%) than for the ICD group (EF = 25.2±0.3%) Further, both CRT-NR subgroups of progressors (n=49; EF = 28.6±0.7%) and non-progressors (n=102; EF = 26.9±0.5%) had also significantly higher baseline LV EF as compared to ICD patients (p<0.05). No statistical significance was found between the two CRT-NR subgroups.

Event free median survival for the overall CRT-NR group (55.6 months) was significantly worse than for the ICD group (79.6; p<0.05). This difference was driven by progressor patients who had a significantly worse event free survival (37.8 months, p<0.05) than ICD patients, while vent free survival in non-progressors (60.8 months) was comparable to ICD patients (p=0.18).

Conclusion

Progressor subgroup of CRT-NR have worse outcome as compared to non-progressors and also to those after primary prevention ICD implantation. The poor prognosis of these patients should have implications for timely decision regarding all therapeutic measures currently available for the management of heart failure.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Project no. TKP2021-EGA-18 has been implemented with the support provided from the National Research, Developement and Innovation Fund of Hungary, financed under the TKP2021-EGA funding scheme

Effects of type of canola protein supplement on ruminal fermentation and nutrient flow to the duodenum in beef heifers

Ruminal fermentation, nutrient digestion, and flows to the duodenum in growing cattle fed differently produced canola protein supplements were studied in a 4 x 4 Latin square design using Speckle Park heifers (initial BW = 451 +/- 26 kg). Canola protein supplement treatments consisted of the following: 1) 8.78% regular canola meal (RCM); 2) 9.25% RCM plus 1.80% canola oil (RCMO); 3) 11.1% canola presscake from biodiesel oil extraction (CPC); and 4) 8.14% high ruminally undegradable protein (RUP) canola meal (RUCM) plus 1.32% canola oil (RUCMO). Experimental diets also contained 39.9, 40.2, 39.9, and 39.9% barley grain; 31.7, 31.4, 31.2, and 31.4% barley silage; and 17.5, 15.2, 15.6, and 16.5% oat hulls for the RCM, RCMO, CPC, and RUCMO diets, respectively. Feeding the CPC, RCMO, and RUCMO diets decreased (P < or = 0.05) ruminal NH(3)-N concentration compared with feeding the RCM diet. Compared with the RCM diet, adding canola oil in the RCMO diet or residual oil in the CPC diet resulted in greater ruminal concentrations of propionate (P < or = 0.09). Additionally, feeding the RCMO diet also resulted in greater ruminal concentrations of acetate (P = 0.07), valerate (P = 0.06), and total VFA (P = 0.07) compared with the RCM diet. Also, compared with the RCM diet, heifers on the RUCMO diet had decreased acetate (P = 0.02) concentrations. The changes in ruminal concentrations of acetate and propionate resulted in reduced acetate:propionate ratios in the RCMO (P = 0.08), CPC (P = 0.02), and RUCMO (P < 0.01) diets. Ruminal digestion and flows of nutrients to the duodenum were not affected by dietary treatment. However, adding canola oil to the RCMO and RUCMO dietary treatments decreased the digestibility of ADF (P < or = 0.08) and NDF (P < or = 0.08) in the total tract compared with the RCM diet. Total tract digestibility of OM was also decreased (P = 0.02) in heifers fed the RUCMO compared with the RCM diet. Notwithstanding the different processing methods employed in making RCM, CPC, or RUCM, there were no differences among the diets for ruminally degraded protein, ruminal microbial protein synthesis, and the flow of N fractions to the duodenum.

Effect of feeding a processed barley/canola meal pellet on performance and carcass quality of feedlot steers

This study was conducted to evaluate the effects of feeding a processed barley/canola meal pellet on feedlot performance and carcass quality of feedlot steers. Cross-bred steers (N = 350) weighing 285 ± 22kg were assigned to 1 of 12 pens and fed either pelleted (PB) or rolled (RB) barley as the concentrate. During backgrounding, cattle were fed a diet that contained 41% PB or RB based-concentrate (DM basis), which consisted of 85% barley and 15% canola meal. During finishing the diet contained 86% concentrate (DM basis), which consisted of 94% pelleted or rolled barley and 6% canola meal. Data collection included daily pen feed intake, individual body weights, ultrasound backfat (USBF) and longissimus dorsi (USLD) area measurements. Carcass data included weight, dressing percentage, marbling and liver abscess scores. Carcass fat, lean and bone percentage, fat color, and l. dorsi intramuscular fat content and fatty acid profile were determined on eight-bone rib samples from 20 randomly selected steers from each treatment. Steers fed the PB had similar ADG during backgrounding (1.29 vs. 1.23 kg d-1; P = 0.30); however, during finishing (1.80 vs. 2.00 kg d-1; P < 0.01) and for the total trial (1.60 vs. 1.70 kg d-1; P < 0.01), daily gains were greater for cattle fed RB. As a result, cattle fed PB were on feed for 10 d longer (P = 0.01) than RB fed cattle. DMI was lower (P < 0.01) for cattle fed PB throughout the trial. Feed conversion (kg feed:kg gain) was superior for the group fed the PB during finishing (6.03 vs. 6.21; P = 0.01) and the total trial (6.27 vs. 6.64; P < 0.01). Both diets produced similar carcasses, but inter-muscular fat percentage was higher (P = 0.03) for the RB group (60.0 vs. 57.4%). Minor differences in fatty acid profile were noted with PB fed steers having higher (P < 0.01) levels of C17:0, C18:3n-3 and C20:4n-6. Results from this study indicate that PB can be used effectively in growing programs, however, further research is required to better manage feeding of PB products to avoid DMI reductions most likely due to sub-acute rumen acidosis. Key words: Cattle, processed barley, performance, carcass quality and composition

Nutritional value of wheat screenings for broiler chickens

Two trials were conducted to study the nutritional value of two wheat screening samples in broiler diets. Experiment 1 evaluated the chemical composition, and energy and amino acid digestibility while, exp. 2 evaluated the performance of 1980 female broiler chickens, housed in straw litter pens, and fed four different levels of the two wheat screening samples. In exp. 2, the wheat screening samples replaced 0%, 25%, 50% and 100% for sample 1 and 0, 25, and 50% for sample 2 of the wheat in diets fed to broilers. Each treatment was replicated six times with 55 birds per replication. The metabolizable energy, and protein content, and mean ileal amino acid digestibility were 3107 kcal kg-1, 15.77%, 83.3%, and 3023 kcal kg-1, 15.19%, 80.4% for wheat screening samples 1 and 2, respectively. The samples contained 90.5 and 88.2% wheat and the major weed seed in both samples was wild buckwheat, which was 4.5 and 6.3% in samples 1 and 2, respectively. In the broiler feeding trial, no significant differences were found between the wheat diet and those containing wheat screenings with regards to growth, feed efficiency, and mortality. There were variations in the composition of wheat screening samples; however, in this study, these variations did not significantly affect the performance of broiler chickens. Wheat screenings totally replaced wheat in balanced broiler diets without negatively affecting performance. Key words: Broiler chicken, feed, wheat screenings, wild buckwheat.