The burden of coronary revascularization associated with lipoprotein(a) in patients with atherosclerotic cardiovascular disease: data from the UK Biobank

Background/Introduction

Elevated lipoprotein(a) [Lp(a)] is an inherited, independent, and causal risk factor for atherosclerotic cardiovascular disease (ASCVD). In a previous analysis of 30,510 ASCVD patients from UK Biobank, adjusted models showed a 100 nmol/L (≈50 mg/dL) difference in Lp(a) was associated with a 19% (95% CI 14–23%) higher risk of coronary revascularization (Welsh P, 2022).

Purpose

To determine the absolute risk for coronary revascularization in an ASCVD population with elevated versus normal Lp(a) levels.

Methods

This was an observational, retrospective study including 32,537 patients from UK Biobank with an ASCVD diagnosis (CHD, cerebrovascular or peripheral arterial disease). Absolute risk (AR) of coronary revascularization (number of coronary revascularizations per 100-person-years) was reported in patients with normal (<65 nmol/L ≈ 30 mg/dL; n=22,257) and elevated (≥150 nmol/L ≈ 70 mg/dL; n=5,204) Lp(a) levels across two time periods: within the first year of ASCVD diagnosis, and using all available follow-up data (median 4.7 years). Lp(a) was measured in an accredited single laboratory using a method standardized to WHO/IFCC reference material. The AR was also calculated for various subgroups within the ASCVD population.

Results

Within the first year after ASCVD diagnosis, 628 (12.07%) of the population with elevated Lp(a) underwent coronary revascularization compared to 1,787 (8.03%) with normal Lp(a). Those with elevated Lp(a) had a higher AR (14.00 per 100-person-years, 95% CI 13.02–14.99; p<0.001) than those with normal Lp(a) (9.34; 95% CI 8.92–9.76). This also held in a subgroup with myocardial infarction (MI; n=9,588), AR of 18.98 (95% CI 16.95–21.01) in those with elevated Lp(a) (n=1,571) vs. AR of 13.02 (95% CI 12.16–13.89) in those with normal Lp(a) (n=6,441) (p<0.001). AR of coronary revascularization within the first year of ASCVD diagnosis was also greater in participants with family history of CV disease (p<0.001) and premature CV disease (<60 years of age) (p<0.001). When using all available follow-up, AR of coronary revascularization was higher in participants with elevated versus normal Lp(a) in the ASCVD population (3.79 vs 2.55; p<0.001) and across all subgroups.

Conclusion

Elevated Lp(a) in patients with ASCVD was associated with increased risk of coronary revascularization in the first year (and subsequently), including those with a prior MI, premature CV disease, or family history of CV disease. Lp(a) testing in ASCVD patients can therefore aid estimations for the risk of revascularization, and thus the targeting of additional therapies to lower such risks.

Funding Acknowledgement

Type of funding sources: None.

Comparative effectiveness of sacubitril/valsartan versus angiotensin converting enzyme inhibitors/angiotensin receptor blockers in de novo heart failure patients

Introduction

Effective use of pharmacological therapy in de novo heart failure (HF) patients is key for slowing down the progression of HF. Randomised clinical trials have shown sacubitril/valsartan (sac/val), providing superior benefit over renin angiotensin system (RAS) blockade with angiotensin converting enzyme inhibitors (ACEi) in patients with HF with reduced ejection fraction (HFrEF) including de novo HF patients. However, real world evidence is scarce.

Purpose

To compare the rate of all-cause hospitalisations in a real world de novo HFrEF US patient population after initiating sac/val or initiating or continuing RAS blockade with ACEi or angiotensin receptor blockers (ARB) within one year of index date.

Methods

This retrospective, non-interventional cohort study included adult de novo HFrEF patients (left ventricular ejection fraction ≤40%), from the Optum Electronic Health Records, from Jan 2016 to Mar 2020 (study period: Dec 2013–Mar 2021) who were prescribed sac/val or ACEi/ARB within 30 days of a new HF diagnosis. Patients either with any history of HF in the prior two years or with prior sac/val treatment were excluded. Index date was defined as the first prescription of sac/val or ACEi/ARB after a new HF diagnosis (≤30 days prior to index). One-to-two greedy propensity score matching was used to balance the study arms on demographics and clinical covariates (medications, LVEF, selected comorbidities). Negative binomial models were used to compare the primary endpoint between treatment groups and across subgroups of interest. The primary endpoint was the rate of all-cause hospitalisations within one year from index. Treatment groups were stratified by age, sex, race, ethnicity, history of myocardial infarction, comorbidities and prior ACEi/ARB treatment. Statistical analyses were conducted using R and SAS software.

Results

Prior to matching, 3,290 patients were initiated on sac/val, 47,678 on ACEi/ARB and post-matching there were 3,290 patients on sac/val and 6,580 patients on ACEi/ARB. Patients with prior ACEi/ARB treatment in both the groups were 1,597 and 2,806, respectively. Mean age was 63.5 in sac/val and 63.7 years in ACEi/ARB groups. After propensity-score matching, the annual rate (per person-year) of all-cause hospitalisation was lower in sac/val compared with ACEi/ARB group, with incidence rate ratio (IRR) of 0.81 (95% confidence interval [CI]: 0.74–0.90) ≤1 year from index. Similarly, in the ACEi/ARB treatment naïve subgroup, sac/val treatment led to 20% reduction in the primary endpoint (IRR: 0.80, 95% CI: 0.69–0.92) compared with ACEi/ARB. Amongst subgroups, results were consistent for most, with significant reduction seen in all-cause hospitalisation rates with sac/val treatment vs. ACEi/ARB.

Conclusion

Treatment with sac/val vs. ACEi or ARB significantly reduced the risk of all-cause hospitalisations in this real-world study supporting the first-line use of sac/val in treating de novo HFrEF patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novartis Pharma AG

A real-world assessment of the burden associated with hospitalizations in US patients with heart failure and left ventricular ejection fraction (LVEF) greater than 40%

Background and purpose

Heart failure (HF) is one of the leading causes of hospitalization among older adults and is associated with a large burden of disease for the individual, the patient's family, healthcare systems, and society. This study assessed the burden of hospitalizations in patients with HF with LVEF >40% in the United States (US).

Methods

This retrospective, non-interventional study identified adult patients with incident or prevalent HF in Optum® de-identified Electronic Health Record (EHR) dataset (2007–2018) between 01/01/2013 and 31/12/2017. Optum's longitudinal EHR repository is derived from dozens of healthcare provider organizations in the US, that include more than 700 Hospitals and 7000 Clinics; treating >95 million patients receiving care in the US. Patients were followed for up to 1 year or until last active date whichever occurred first. Comorbidities, all-cause hospitalizations (AcH) and primary cause HF hospitalizations (HFH) were analysed.

Results

120,606 patients with HF and LVEF >40% (54% female) with a mean (SD) age of 71 (13) yrs were included, representing 80,324.74 patient-yrs follow-up (days). Common comorbidities were hypertension (91.8%), ischemic heart disease (IHD, 71.4%), atrial fibrillation (AF, 54.8%), renal disease (54.1%), type 2 diabetes (T2D, 50.7%), obesity (44.6%) and anemia (39%). Comorbidities including IHD (72.9% vs. 68.4%), AF (56.4% vs. 51.6%) and T2D (51.1% vs. 49.9%) were more often recorded in patients with LVEF >40-≤60% than >60% cohort while hypertension (91.6% vs. 92.2%), renal disease (53.8% vs. 54.6%), obesity (43.9% vs. 46.1%) and anemia (38.1% vs. 40.9%) had significantly higher frequency in the LVEF >60% cohort. The annualized AcH rate for patients with LVEF>40% was 1.44 and annualized HFH rate was 0.24 with a median length of stay of 3 and 4 days, respectively. Annualized hospitalization rates were significantly higher for women than men (both AcH and HFH). AcH rates were significantly higher and HFH rates were significantly lower for patients with LVEF>60% compared with LVEF >40-≤60.

Conclusions

This study demonstrates that patients with HF and LVEF >40% experience significant burden from comorbidities and hospitalizations from any-cause and for HF. The hospitalization rates are higher in women (both AcH and HFH) or patients with LVEF >60% (AcH only). Further focus on reduction of hospitalizations and interdisciplinary management of patients with HF should be warranted.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Novartis Pharma AG

Analysis of genetic variation contributing to measured speed in Thoroughbreds identifies genomic regions involved in the transcriptional response to exercise

Despite strong selection for athletic traits in Thoroughbred horses, there is marked variation in speed and aptitude for racing performance within the breed. Using global positioning system monitoring during exercise training, we measured speed variables and temporal changes in speed with age to derive phenotypes for GWAS. The aim of the study was to test the hypothesis that genetic variation contributes to variation in end-point physiological traits, in this case galloping speed measured during field exercise tests. Standardisation of field-measured phenotypes was attempted by assessing horses exercised on the same gallop track and managed under similar conditions by a single trainer. PCA of six key speed indices captured 73.9% of the variation with principal component 1 (PC1). Verifying the utility of the phenotype, we observed that PC1 (median) in 2-year-old horses was significantly different among elite, non-elite and unraced horses (P < 0.001) and the temporal change with age in PC1 varied among horses with different myostatin (MSTN) g.66493737C>T SNP genotypes. A GWAS for PC1 in 2-year-old horses (n = 122) identified four SNPs reaching the suggestive threshold for association (P < 4.80 × 10^-5 ), defining a 1.09 Mb candidate region on ECA8 containing the myosin XVIIIB (MYO18B) gene. In a GWAS for temporal change in PC1 with age (n = 168), five SNPs reached the suggestive threshold for association and defined candidate regions on ECA2 and ECA11. Both regions contained genes that are significantly differentially expressed in equine skeletal muscle in response to acute exercise and training stimuli, including MYO18A. As MYO18A plays a regulatory role in the skeletal muscle response to exercise, the identified genomic variation proximal to the myosin family genes may be important for the regulation of the response to exercise and training.

Genetic contributions to precocity traits in racing Thoroughbreds

Adaptation to early training and racing (i.e. precocity), which is highly variable in racing Thoroughbreds, has implications for the selection and training of horses. We hypothesised that precocity in Thoroughbred racehorses is heritable. Age at first sprint training session (work day), age at first race and age at best race were used as phenotypes to quantify precocity. Using high-density SNP array data, additive SNP heritability (hSNP2) was estimated to be 0.17, 0.14 and 0.17 for the three traits respectively. In genome-wide association studies (GWAS) for age at first race and age at best race, a 1.98-Mb region on equine chromosome 18 (ECA18) was identified. The most significant association was with the myostatin (MSTN) g.66493737C>T SNP (P = 5.46 × 10^-12 and P = 1.89 × 10^-14 respectively). In addition, two SNPs on ECA1 (g.37770220G>A and g.37770305T>C) within the first intron of the serotonin receptor gene HTR7 were significantly associated with age at first race and age at best race. Although no significant associations were identified for age at first work day, the MSTN:g.66493737C>T SNP was among the top 20 SNPs in the GWAS (P = 3.98 × 10^-5 ). Here we have identified variants with potential roles in early adaptation to training. Although there was an overlap in genes associated with precocity and distance aptitude (i.e. MSTN), the HTR7 variants were more strongly associated with precocity than with distance. Because HTR7 is closely related to the HTR1A gene, previously implicated in tractability in young Thoroughbreds, this suggests that behavioural traits may influence precocity.