Abstract 100: Blood Pressure Targets and Hemodynamics According to Initial Blood Lactate Levels in Patients With Comatose Out-of-Hospital Cardiac Arrest – A Substudy of the BOX Trial

Circulation, Volume 148, Issue Suppl_1, Page A100-A100, November 6, 2023. Out-of-hospital cardiac arrest (OHCA) patients are often circulatory unstable and have high mortality in the first days following resuscitation. An increase in lactate will reflect the severity and duration of hypoperfusion in out-of-hospital cardiac arrest (OHCA). Further, the severity of hypoperfusion could modify the effect on survival and neurological injury of different mean arterial blood pressure (MAP) targets. In this sub-study of the BOX trial, adults successfully resuscitated comatose OHCA patients (n=789) with a presumed cardiac cause were randomized to a MAP 63 mmHg vs. 77 mmHg. Patients were arbitrarily grouped in low-lactate: 75 % according to blood lactate levels at hospital arrival as a surrogate of severity of hypoperfusion. Invasive evaluations were performed using an arterial line and pulmonary artery catheter (PAC). Logistic regression analysis evaluated whether lactate levels (as continuous and categorical) modify the effect of MAP targets on 1-year mortality. The three lactate groups were: low-lactate: 7.9 mmol/L. The vasoactive inotropic score was higher with increasing initial lactate level with the largest difference at 6 hours (low-lactate: 7.8 (95%CI: 5.7 – 10.1) vs. high-lactate: 16.4 (95%CI: 13.4 – 19.6). No difference in the cardiac index or systemic vascular resistance was observed between lactate groups. The initial lactate level modified the effect of the two MAP targets (p=0.044), with a tendency to higher mortality for high-lactate patients if the MAP target were 77 mmHg (odds ratio: 1.7 (95%CI: 0.9-3.0, p=0.08). Comatose OHCA patients with high initial lactate levels required more vasoactive drugs on the first two days of ICU admission to meet the blood pressure target and have a poorer prognosis. The results do not support a higher MAP target benefit for patients with an initial high lactate level in the first 48 hours.

Leggi
Novembre 2023

Abstract 18657: Diagnostic Yield of Whole Genome Sequencing in Congenital Heart Disease: Data From the UK 100,000 Genomes Project

Circulation, Volume 148, Issue Suppl_1, Page A18657-A18657, November 6, 2023. Congenital heart disease (CHD) is the most common birth defect affecting around 1% global live births. The aetiology of CHD is poorly understood: while a number genetic loci have already been identified, the majority of cases remain unexplained. Many CHD cases occur with additional abnormalities, or as part of a defined syndrome (eg. Noonan or CHARGE syndromes). The 100,000 Genomes Project conducted whole genome sequencing for patients with a range of rare diseases and cancers in partnership with the UK National Health Service. We analysed clinical and genetic data from the project in 2638 participants with CHD, including both primary CHD cases and secondary cases who have CHD as part of a syndromic presentation but were recruited under other disease categories. Both cohorts are primarily composed of patients with CHD accompanied by additional extra-cardiac abnormalities without a prior diagnosis of a defined syndrome. We found that families recruited as primary CHD cases were significantly less likely to have been classed as “solved cases” (indicating a pathogenic variant has been identified) than phenotypically similar secondary CHD cases (5.4% primary, 16.2% secondary; p = 6.78х-11). This is primarily due to differences in the gene lists used in analysis, with the majority of diagnoses in both groups due to genes not included in the CHD gene panel (83% primary and 97% secondary cases). Expanding standard CHD screening to include a wider range of syndromic CHD genes is likely to increase the diagnostic yield for the primary CHD cohort by more than two-fold. Copy number variants (CNVs) also contribute to CHD, especially in cases with additional abnormalities. CHD cases have a significantly higher burden of both deletions (p = 1.00х10-5) and duplications (p = 0.009) than an ethnically-matched control cohort. However, only 7 of 2638 participants have CNVs in known CHD-causative regions such as the 22q11.2 or Williams-Beuren syndrome regions indicating novel CNVs are likely to contribute to a significant number of cases. Wider screening of syndromic CHD genes and novel copy number variants is likely significantly increase the diagnostic yield for CHD both within the 100,000 Genomes Project and in healthcare settings, and potentially yield novel CHD-associated loci.

Leggi
Novembre 2023