The influence of heart failure on clinical and economic outcomes among older adults ≥75 years of age with acute myocardial infarction.

BACKGROUND: We aimed to evaluate the influence of heart failure (HF) on clinical and economic outcomes among older adults ≥75 years of age during their acute myocardial infarction (AMI) admission in large population-based study from the United States. We also evaluated the clinical characteristics associated with the presence of HF and the predictors of mortality, healthcare utilization, and cost among older adults with AMI. METHODS: From January 1, 2000, to December 31, 2016, AMI admission was identified using the primary diagnosis and concomitant HF was identified using any non-primary diagnoses in the Premier Healthcare Database. RESULTS: Of the 468,654 patients examined, 42,946 (9%) had concomitant HF during their AMI admission. These patients were older, more often female, and were more likely to be White. Patients with concomitant HF were more likely to be frail than non-HF patients (59% vs 15%, P < .001). The mean (SD) Elixhauser comorbidity index was 2.6 (2.5) vs 0.4 (1.1), P < .001 in the AMI with HF vs AMI only group. The use of percutaneous coronary intervention in those with AMI and HF was lower than those with AMI only (15% vs 31%, P < .001). The overall mortality rate for those with HF was 12%, the median [IQR] hospital length of stay was 5 [3,9] days, and only 25% of patients were discharged home. A higher proportion of patients were discharged to rehabilitation or hospice if they had AMI and HF (Rehabilitation: 33% vs 20%, P < .001; Hospice: 5% vs 3%, P < .001). The mean unadjusted cost of an AMI hospitalization in patients with concomitant HF was lower ($12,411 ± $14,860) than in those without HF ($15,828 ± $19,330). After adjusting for age, gender, race, hypertension, frailty, revascularization strategy, and death, the average cost of hospitalization attributed to concomitant HF was +$1,075 (95% CI +876 to $1,274) when compared to AMI patients without HF. CONCLUSION: In patients ≥75 years of age, AMI with concomitant HF carries higher risk of death, but at ages ≥85 years, the risk difference diminishes due to other competing risks. HF was also associated with longer hospital length of stay and higher likelihood of referral to hospice and rehabilitation facilities when compared to older patients without HF. Care for these older adults is associated with increased hospitalization costs. Measures to identify HF in older adults during their AMI admission are necessary to optimize health outcomes, care delivery, and costs.

How to use serum creatinine, cystatin C and GFR.

Glomerular filtration rate (GFR) is the best overall measure of kidney function. The GFR is relatively low at birth but increases through infancy and early childhood to reach adult levels of approximately 120 mL/min/1.73 m2 by age 2. While GFR can be measured most accurately by the urinary clearance of an exogenous ideal filtration marker such as inulin, it is more clinically useful to estimate GFR using a single serum measurement of an endogenous biomarker such as creatinine or cystatin C. When in steady state, there is an inverse relationship between creatinine/cystatin C and GFR, allowing GFR to be estimated from either using simple equations. Because of the non-linear relationship between creatinine/cystatin C and GFR, relatively small initial increases in these markers represent significant decreases in GFR. While cystatin C is produced by all nucleated cells, creatinine is a waste product of muscle metabolism and is therefore influenced by diet and muscle mass/body habitus. Decreased GFR is used to diagnose and stage chronic kidney disease (CKD) using the Kidney Disease: Improving Global Outcomes system. A diagnosis of CKD requires GFR <60 mL/min/1.73 m2 for more than 3 months; higher GFR also represents CKD if evidence of kidney damage (such as albuminuria or abnormal imaging) is present. Changes in serum creatinine and urine output are used to diagnose acute kidney injury. It is possible to calculate a kinetic GFR when the creatinine is changing rapidly, though more complex calculations are required.

Lactobacillus endocarditis in a healthy patient with probiotic use.

Lactobacilli are commensal anaerobic gram-positive rod organisms that are normal flora of the oral, genitourinary, and gastrointestinal tracts. Lactobacillus rhamnosus is now commonly found in probiotics. They are rarely pathogenic, but occasional cases of bacteremia and associated endocarditis have been noted in patients with pre-disposing factors. We describe a case of Lactobacillus endocarditis in an otherwise healthy patient with probiotic use and gingival laceration and present an accompanying discussion of the potential association of probiotic formulations containing lactobacilli and systemic infection.

Deletion of the Arp2/3 complex in megakaryocytes leads to microthrombocytopenia in mice.

Actin reorganization regulates key processes in platelet activation. Here we examined the role of the Arp2/3 complex, an essential component in actin filament branching, in platelet function. The Arpc2 gene, encoding the p34 subunit of the Arp2/3 complex, was deleted in the megakaryocyte lineage (Arpc2fl/flPF4-Cre). Deletion of the Arp2/3 complex resulted in marked microthrombocytopenia in mice, caused by premature platelet release into the bone marrow compartment and impaired platelet survival in circulation. Arpc2fl/flPF4-Cre platelets exhibited alterations in their actin cytoskeleton and their peripheral microtubule coil. Thrombocytopenia was alleviated following clodronate liposome-induced macrophage depletion in Arpc2fl/flPF4-Cre mice. Arpc2fl/flPF4-Cre platelets failed to spread and showed a mild defect in integrin activation and aggregation. However, no significant differences in hemostasis or thrombosis were observed between Arpc2fl/flPF4-Cre and control mice. Thus, Arp2/3 is critical for platelet homeostasis but plays only a minor role for vascular hemostasis.