Healthcare resource utilization and expenditures among newly-diagnosed elderly non-valvular atrial fibrillation patients initiating oral anticoagulants.

Aims: Non-valvular atrial fibrillation (NVAF) prevalence increases with age. Hence, evaluating the economic burden among older-aged patients is vital. This study aimed to compare healthcare resource utilization (HRU) and costs among newly-diagnosed older-aged NVAF patients treated with warfarin, rivaroxaban, or apixaban vs. dabigatran.Materials and Methods: Newly-diagnosed older-aged (aged ≥65 years) NVAF patients initiating dabigatran, warfarin, rivaroxaban, or apixaban (first prescription date = index date) from 01JAN2010-31DEC2015 and with continuous enrollment for ≥12 months pre-index date were included from 100% Medicare database. Patient data were assessed until drug discontinuation/switch/dose change/death/disenrollment/study end (up to 12 months). Dabigatran initiators were 1:1 propensity score-matched (PSM) with warfarin, rivaroxaban, or apixaban initiators. Generalized linear models were used to compare all-cause HRU and costs per-patient-per-month (PPPM) between the matched cohorts.Results: After PSM with dabigatran, 70,531 warfarin, 51,673 rivaroxaban, and 25,209 apixaban patients were identified. Dabigatran patients had significantly fewer generalized-linear-model-adjusted PPPM hospitalizations (0.114 vs. 0.123; 0.111 vs. 0.121), and outpatient visits (2.864 vs. 4.201; 2.839 vs. 2.949) than warfarin and rivaroxaban patients, respectively, but had significantly more PPPM hospitalizations (0.103 vs. 0.090) and outpatient visits (2.780 vs. 2.673) than apixaban patients (all p < .0001). Dabigatran patients incurred significantly lower adjusted total PPPM costs ($3,309 vs. $3,362; $3,285 vs. $3,474) than warfarin and rivaroxaban patients, respectively (all p < .01) but higher total PPPM costs ($3,192 vs. $2,986) than apixaban patients (all p < .0001).Limitations: This study is subject to the inherent limitations of any claims dataset, including potential bias from coding errors and identification of medical conditions using diagnosis codes as opposed to clinical evidence. Medications filled over-the-counter or provided as samples by the physician are never captured in claims data.Conclusions: Newly-diagnosed older-aged NVAF patients initiating dabigatran incurred significantly lower adjusted all-cause HRU and costs than warfarin and rivaroxaban patients but higher adjusted HRU and costs than apixaban patients.

Vitamin D and Mortality.

In this narrative review, we aim to summarize and discuss the current evidence linking vitamin D and mortality. Low 25-hydroxyvitamin D [25(OH)D] concentrations are associated with an increased risk of mortality. This has been shown in different cohort studies including general populations, as well as various patient cohorts. Some single-study results and meta-analyses indicate that the shape of the relationship between 25(OH)D and mortality follows a U- or a reverse J-shaped curve. Interassay and laboratory differences are, however, a limitation of most previous surveys, and standardization of 25(OH)D measurements is needed for future investigations. Apart from observational data, it has been documented in meta-analyses of randomized controlled trials that vitamin D3 supplementation is associated with a moderate, yet statistically significant, reduction in mortality. This latter finding must be interpreted in light of some limitations such as incomplete follow-up data, but such a reduction of mortality with vitamin D3 supplementation as the finding of meta-analyses of randomized controlled trials strongly argues for the benefits and, importantly, also the safety of vitamin D.

Homoarginine in the renal and cardiovascular systems.

Homoarginine (hArg) is an endogenous, nonproteinogenic amino acid which differs from arginine by an additional methylene (CH2) group in the backbone. In this brief narrative review, we summarize the current literature on hArg in the renal and cardiovascular systems. Epidemiological studies have identified low hArg levels as an independent risk marker for cardiovascular, cerebrovascular, and renal diseases as well as for mortality. The relatively low correlation of hArg with established cardiovascular risk factors underlines its great potential as an emerging biomarker to improve risk prediction because plasma hArg concentrations might reflect previously unrecognized pathophysiological processes. hArg may be involved in the pathogenesis of various diseases due to its effects on nitric oxide (NO) and energy metabolism. In view of its structural similarities with arginine, it has been proposed that hArg impacts on arginine metabolism and subsequently also on NO synthesis. The key enzyme for hArg synthesis, arginine:glycine amidinotransferase (AGAT), is involved in the synthesis of energy metabolites including guanidinoacetate, the precursor of creatine. Therefore, the involvement of hArg in energy metabolism could partially explain the close association between hArg and cardiovascular diseases such as heart failure. Whether hArg supplementation or modification of key enzymes of hArg metabolism such as AGAT activity is effective for the treatment of chronic diseases remains to be elucidated.

Vitamin D in preventive medicine.

The global burden of vitamin D deficiency is of great concern for public health. Meta-analyses of randomized controlled trials (RCTs) have shown that vitamin D supplementation reduces fractures, falls, and mortality. These findings are, however, not universally accepted and there exists certain controversy regarding the potential benefits of vitamin D. Whereas vitamin D might also be relevant for extra-skeletal diseases such as cancer, cardiovascular diseases, or infections, the recommended Dietary Reference Intakes (DRI) are solely based on skeletal effects. The Recommended Dietary Allowance (RDA) range from 600 to 800 international units (IU) of vitamin D per day, corresponding to a 25-hydroxyvitamin D level of 20 ng/mL (50 nmol/L). Consequently, there exists a substantial gap between the RDA and the actual high prevalence of vitamin D deficiency in general populations, particularly among the elderly. Therefore, achieving the RDA will require additional efforts including food fortification, vitamin D supplementation and health campaigns.