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Association of Statin Dose With Amputation and Survival in Patients With Peripheral Artery Disease [Original Research Article]

Lun, 02/04/2018 - 19:40
Background:Statin dose guidelines for patients with peripheral artery disease (PAD) are largely based on coronary artery disease and stroke data. The aim of this study is to determine the effect of statin intensity on PAD outcomes of amputation and mortality.Methods:Using an observational cohort study design and a validated algorithm, we identified patients with incident PAD (2003–2014) in the national Veterans Affairs data. Highest statin intensity exposure (high-intensity versus low-to-moderate–intensity versus antiplatelet therapy but no statin use) was determined within 1 year of diagnosis of PAD. Outcomes of interest were lower extremity amputations and death. The association of statin intensity with incident amputation and mortality was assessed with Kaplan-Meier plots, Cox proportional hazards modeling, propensity score–matched analysis, and sensitivity and subgroup analyses, as well, to reduce confounding.Results:In 155?647 patients with incident PAD, more than a quarter (28%) were not on statins. Use of high-intensity statins was lowest in patients with PAD only (6.4%) in comparison with comorbid coronary/carotid disease (18.4%). Incident amputation and mortality risk declined significantly with any statin use in comparison with the antiplatelet therapy–only group. In adjusted Cox models, the high-intensity statin users were associated with lower amputation risk and mortality in comparison with antiplatelet therapy–only users (hazard ratio, 0.67; 95% confidence interval, 0.61–0.74 and hazard ratio, 0.74; 95% confidence interval, 0.70–0.77, respectively). Low-to-moderate–intensity statins also had significant reductions in the risk of amputation and mortality (hazard ratio amputation, 0.81; 95% confidence interval, 0.75– 0.86; hazard ratio death, 0.83; 95% confidence interval, 0.81–0.86) in comparison with no statins (antiplatelet therapy only), but effect size was significantly weaker than the high-intensity statins (P<0.001). The association of high-intensity statins with lower amputation and death risk remained significant and robust in propensity score–matched, sensitivity, and subgroup analyses.Conclusions:Statins, especially high-intensity formulations, are underused in patients with PAD. This is the first population-based study to show that high-intensity statin use at the time of PAD diagnosis is associated with a significant reduction in limb loss and mortality in comparison with low-to-moderate–intensity statin users, and patients treated only with antiplatelet medications but not with statins, as well.

Cardiovascular Outcomes and Risks After Initiation of a Sodium Glucose Cotransporter 2 Inhibitor [Original Research Article]

Lun, 02/04/2018 - 19:40
Background:Clinical trials have shown cardiovascular benefits and potential risks from sodium glucose cotransporter 2 inhibitors (SGLT2i). Trials may have limited ability to address individual end points or safety concerns.Methods:We performed a population-based cohort study among patients with type 2 diabetes mellitus with established cardiovascular disease newly initiated on antihyperglycemic agents within the US Department of Defense Military Health System between April 1, 2013, and December 31, 2016. Incidence rates, hazard ratios (HRs), and 95% confidence intervals (CIs) for time to first composite end point of all-cause mortality and hospitalization for heart failure event, major adverse cardiovascular events (defined as all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke), and individual end points were evaluated using conditional Cox models comparing new SGLT2i users with other antihyperglycemic agents. The exploratory safety end point was below-knee lower extremity amputation. Intent-to-treat and on-treatment analyses were performed.Results:After propensity matching, 25?258 patients were followed for a median of 1.6 years. Compared with non-SGLT2i, initiation of SGLT2i was associated with a lower rate of all-cause mortality and hospitalization for heart failure (1.73 versus 3.01 events per 100 person-years; HR, 0.57; 95% CI, 0.50–0.65) and major adverse cardiovascular events (2.31 versus 3.45 events per 100 person-years; HR, 0.67; 95% CI, 0.60–0.75). SGLT2i initiation was also associated with an ?2-fold higher risk of below-knee lower extremity amputation (0.17 versus 0.09 events per 100 person-years; HR, 1.99; 95% CI, 1.12–3.51). Because of the disproportionate canagliflozin exposure in the database, the majority of amputations were observed on canagliflozin. Results were consistent in the on-treatment analysis.Conclusions:In this high-risk cohort, initiation of SGLT2i was associated with lower risk of all-cause mortality, hospitalization for heart failure, and major adverse cardiovascular events and higher risk of below-knee lower extremity amputation. Findings underscore the potential benefit and risks to be aware of when initiating SGLT2i. It remains unclear whether the below-knee lower extremity amputation risk extends across the class of medication, because the study was not powered to make comparisons among individual treatments.

Effect of Losartan on Right Ventricular Dysfunction [Original Research Article]

Lun, 02/04/2018 - 19:40
Background:The effect of angiotensin II receptor blockers on right ventricular (RV) function is still unknown. Angiotensin II receptor blockers are beneficial in patients with acquired left ventricular dysfunction, and recent findings have suggested a favorable effect in symptomatic patients with systemic RV dysfunction. The current study aimed to determine the effect of losartan, an angiotensin II receptor blocker, on subpulmonary RV dysfunction in adults after repaired tetralogy of Fallot.Methods:The REDEFINE trial (Right Ventricular Dysfunction in Tetralogy of Fallot: Inhibition of the Renin-Angiotensin-Aldosterone System) is an investigator-initiated, multicenter, prospective, 1:1 randomized, double-blind, placebo-controlled study. Adults with repaired tetralogy of Fallot and RV dysfunction (RV ejection fraction [EF] <50%) but without severe valvular dysfunction were eligible. Patients were randomly assigned between losartan (150 mg daily) and placebo with target treatment duration between 18 and 24 months. The primary outcome was RV EF change, determined by cardiovascular MRI in intention-to-treat analysis.Results:Of 95 included patients, 47 patients received 150 mg losartan daily (age, 38.0±12.4 years; 74% male), and 48 patients received placebo (age, 40.6±11.4 years; 63% male). Overall, RV EF did not change in patients allocated to losartan (n=42) (44.4±5.1% to 45.2±5.0%) and placebo (n=46) (43.2±6.3% to 43.6±6.9%). Losartan did not significantly improve RV EF in comparison with placebo (+0.51%; 95% confidence interval, –1.0 to +2.0; P=0.50). No significant treatment effects were found on secondary outcomes: left ventricular EF, peak aerobic exercise capacity, and N-terminal pro–brain natriuretic peptide (P>0.30 for all). In predefined subgroup analyses, losartan did not have a statistically significant impact on RV EF in subgroups with symptoms, restrictive RV, RV EF<40%, pulmonary valve replacement, or QRS fragmentation. However, in a post hoc analysis, losartan was associated with improved RV EF in a subgroup (n=30) with nonrestrictive RV and incomplete remodeling (QRS fragmentation and previous pulmonary valve replacement) (+2.7%; 95% confidence interval, +0.1 to +5.4; P=0.045).Conclusions:Losartan had no significant effect on RV dysfunction or secondary outcome parameters in repaired tetralogy of Fallot. Future larger studies may determine whether there might be a role for losartan in specific vulnerable subgroups.Clinical Trial Registration:URL: https://www.clinicaltrials.gov. Unique identifier: NCT02010905.

Angiography Versus Hemodynamics to Predict the Natural History of Coronary Stenoses [Original Research Article]

Lun, 02/04/2018 - 19:40
Background:Among patients with documented stable coronary artery disease and in whom no revascularization was performed, we compared the respective values of angiographic diameter stenosis (DS) and fractional flow reserve (FFR) in predicting natural history.Methods:The present analysis included the 607 patients from the FAME 2 trial (Fractional Flow Reserve Versus Angiography in Multivessel Evaluation 2) in whom no revascularization was performed. FFR varied from 0.20 to 1.00 (average 0.74±0.16), and DS (by quantitative coronary analysis) varied from 8% to 98% (average 53±15). The primary end point, defined as vessel-oriented clinical end point (VOCE) at 2 years, was a composite of prospectively adjudicated cardiac death, vessel-related myocardial infarction, vessel-related urgent, and not urgent revascularization. The stenoses were divided into 4 groups according to FFR and %DS values: positive concordance (FFR?0.80; DS?50%), negative concordance (FFR>0.80; DS<50%), positive mismatch (FFR?0.80; DS<50%), and negative mismatch (FFR>0.80; DS?50%).Results:The rate of VOCE was highest in the positive concordance group (log rank: X2=80.96; P=0.001) and lowest in the negative concordance group. The rate of VOCE was higher in the positive mismatch group than in the negative mismatch group (hazard ratio, 0.38; 95% confidence interval, 0.21–0.67; P=0.001). There was no significant difference in VOCE between the positive concordance and positive mismatch groups (FFR?0.80; hazard ratio, 0.77; 95% confidence interval, 0.57–1.09; P=0.149) and no significant difference in rate of VOCE between the negative mismatch and negative concordance groups (FFR>0.80; hazard ratio, 1.89; 95% confidence interval, 0.96–3.74; P=0.067).Conclusions:In patients with stable coronary disease, physiology (FFR) is a more important determinant of the natural history of coronary stenoses than anatomy (DS).Clinical Trial Registration:URL: https://clinicaltrials.gov. Unique identifier: NCT01132495.

Targeting Transmembrane BAX Inhibitor Motif Containing 1 Alleviates Pathological Cardiac Hypertrophy [Original Research Article]

Lun, 02/04/2018 - 19:40
Background:Cardiac hypertrophy and its resultant heart failure are among the most common causes of mortality worldwide. Abnormal protein degradation, especially the impaired lysosomal degradation of large organelles and membrane proteins, is involved in the progression of cardiac hypertrophy. However, the underlying mechanisms have not been fully elucidated.Methods:We investigated cardiac transmembrane BAX inhibitor motif containing 1 (TMBIM1) mRNA and protein expression levels in samples from patients with heart failure and mice with aortic banding (AB)–induced cardiac hypertrophy. We generated cardiac-specific Tmbim1 knockout mice and cardiac-specific Tmbim1-overexpressing transgenic mice and then challenged them with AB surgery. We used microarray, confocal image, and coimmunoprecipitation analyses to identify the downstream targets of TMBIM1 in cardiac hypertrophy. Tmbim1/Tlr4 double-knockout mice were generated to investigate whether the effects of TMBIM1 on cardiac hypertrophy were Toll-like receptor 4 (TLR4) dependent. Finally, lentivirus-mediated TMBIM1 overexpression in a monkey AB model was performed to evaluate the therapeutic potential of TMBIM1.Results:TMBIM1 expression was significantly downregulated on hypertrophic stimuli in both human and mice heart samples. Silencing cardiac Tmbim1 aggravated AB-induced cardiac hypertrophy. This effect was blunted by Tmbim1 overexpression. Transcriptome profiling revealed that the TLR4 signaling pathway was disrupted dramatically by manipulation of Tmbim1. The effects of TMBIM1 on cardiac hypertrophy were shown to be dependent on TLR4 in double-knockout mice. Fluorescent staining indicated that TMBIM1 promoted the lysosome-mediated degradation of activated TLR4. Coimmunoprecipitation assays confirmed that TMBIM1 directly interacted with tumor susceptibility gene 101 via a PTAP motif and accelerated the formation of multivesicular bodies that delivered TLR4 to the lysosomes. Finally, lentivirus-mediated TMBIM1 overexpression reversed AB-induced cardiac hypertrophy in monkeys.Conclusions:TMBIM1 protects against pathological cardiac hypertrophy through promoting the lysosomal degradation of activated TLR4. Our findings reveal the central role of TMBIM1 as a multivesicular body regulator in the progression of pathological cardiac hypertrophy, as well as the role of vesicle trafficking in signaling regulation during cardiac hypertrophy. Moreover, targeting TMBIM1 could be a novel therapeutic strategy for treating cardiac hypertrophy and heart failure.

Ultrasound for Lower Extremity Deep Venous Thrombosis [Consensus Report]

Lun, 02/04/2018 - 19:40
Venous ultrasound is the standard imaging test for patients suspected of having acute deep venous thrombosis (DVT). There is variability and disagreement among authoritative groups regarding the necessary components of the test. Some protocols include scanning the entire lower extremity, whereas others recommend scans limited to the thigh and knee supplemented with serial testing. Some protocols use gray-scale ultrasound alone, whereas others include Doppler interrogation. Point-of-care ultrasound is recommended in some settings, and there is heterogeneity of these protocols as well. Heterogeneity of recommendations can lead to errors including incorrect application of guidelines, confusion among requesting physicians, and incorrect follow-up. In October 2016, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to evaluate the current evidence to develop recommendations regarding ultrasound protocols for DVT and the terminology used to communicate results to clinicians. Recommendations were made after open discussion and by unanimous consensus.The panel recommends a comprehensive duplex ultrasound protocol from thigh to ankle with Doppler at selected sites rather than a limited or complete compression-only examination. This protocol is currently performed in many facilities and is achievable with standard ultrasound equipment and personnel. The use of these recommendations will increase the diagnosis of calf DVT and provide better data to explain the presenting symptoms. The panel recommends a single point-of-care protocol that minimizes underdiagnoses of proximal DVT.The panel recommends the term chronic postthrombotic change to describe the residual material that persists after the acute presentation of DVT to avoid potential overtreatment of prior thrombus.Adoption of a single standardized comprehensive duplex ultrasound and a single point-of-care examination will enhance patient safety and clinicians’ confidence.

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