Research Spotlight

Werchan, C. A., A. M. Steele, T. Janssens, M. W. Millard and T. Ritz (2018). “Towards an assessment of perceived COPD exacerbation triggers: Initial development and validation of a questionnaire.” Respirology Jul 13. [Epub ahead of print].

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BACKGROUND AND OBJECTIVE: Prevention of exacerbations in chronic obstructive pulmonary disease (COPD) is important to decrease overall declines in functioning and improve quality of life. The present study sought to develop a psychometrically valid measure of perceived triggers of exacerbations in COPD patients, the COPD Exacerbation Trigger Inventory (CETI). METHODS: Participants (n = 192) were recruited through local clinics and online to complete surveys of the CETI, demographic information, disease-specific information and the COPD Assessment Test (CAT). The CETI included a free response section on patients’ individual top triggers, combined with ratings of their controllability. RESULTS: Exploratory principal component analyses identified a stable 5-factor structure (33 items), from which trigger subscales for weather/climate, air pollution/irritants, exercise, infection/illness and psychological factors were formed (internal consistency Cronbach’s alpha = 0.90-0.94). Trigger factors were associated with COPD functional status, exacerbation frequency and healthcare utilization. Participants found personal triggers related to dust, air pollution, smoking and physical activity to be the most easily controlled, whereas those related to psychological factors, climate, infection, respiratory symptoms and sleep to be more difficult to control. Greater perceived controllability of triggers was associated with lower CAT scores, indicating better health status and less impact of the disease on functioning. CONCLUSION: The CETI is a psychometrically valid measure of perceived exacerbation triggers in patients with COPD. Perceived triggers are associated with clinical outcomes. Assessment of trigger classes and their controllability may prove useful in both research and clinical settings with COPD patients and to further our knowledge in prevention and disease management.

Kandzari, D. E., M. Bohm, F. Mahfoud, R. R. Townsend, M. A. Weber, S. Pocock, K. Tsioufis, D. Tousoulis, J. W. Choi, C. East, S. Brar, S. A. Cohen, M. Fahy, G. Pilcher and K. Kario (2018). “Effect of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial.” Lancet 391(10137): 2346-2355.

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BACKGROUND: Previous catheter-based renal denervation studies have reported variable efficacy results. We aimed to evaluate safety and blood pressure response after renal denervation or sham control in patients with uncontrolled hypertension on antihypertensive medications with drug adherence testing. METHODS: In this international, randomised, single-blind, sham-control, proof-of-concept trial, patients with uncontrolled hypertension (aged 20-80 years) were enrolled at 25 centres in the USA, Germany, Japan, UK, Australia, Austria, and Greece. Eligible patients had an office systolic blood pressure of between 150 mm Hg and 180 mm Hg and a diastolic blood pressure of 90 mm Hg or higher; a 24 h ambulatory systolic blood pressure of between 140 mm Hg and 170 mm Hg at second screening; and were on one to three antihypertensive drugs with stable doses for at least 6 weeks. Patients underwent renal angiography and were randomly assigned to undergo renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were masked to randomisation assignments. The primary efficacy endpoint was blood pressure change from baseline (measured at screening visit two), based on ambulatory blood pressure measurements assessed at 6 months, as compared between treatment groups. Drug surveillance was used to assess medication adherence. The primary analysis was done in the intention-to-treat population. Safety events were assessed through 6 months as per major adverse events. This trial is registered with ClinicalTrials.gov, number NCT02439775, and follow-up is ongoing. FINDINGS: Between July 22, 2015, and June 14, 2017, 467 patients were screened and enrolled. This analysis presents results for the first 80 patients randomly assigned to renal denervation (n=38) and sham control (n=42). Office and 24 h ambulatory blood pressure decreased significantly from baseline to 6 months in the renal denervation group (mean baseline-adjusted treatment differences in 24 h systolic blood pressure -7.0 mm Hg, 95% CI -12.0 to -2.1; p=0.0059, 24 h diastolic blood pressure -4.3 mm Hg, -7.8 to -0.8; p=0.0174, office systolic blood pressure -6.6 mm Hg, -12.4 to -0.9; p=0.0250, and office diastolic blood pressure -4.2 mm Hg, -7.7 to -0.7; p=0.0190). The change in blood pressure was significantly greater at 6 months in the renal denervation group than the sham-control group for office systolic blood pressure (difference -6.8 mm Hg, 95% CI -12.5 to -1.1; p=0.0205), 24 h systolic blood pressure (difference -7.4 mm Hg, -12.5 to -2.3; p=0.0051), office diastolic blood pressure (difference -3.5 mm Hg, -7.0 to -0.0; p=0.0478), and 24 h diastolic blood pressure (difference -4.1 mm Hg, -7.8 to -0.4; p=0.0292). Evaluation of hourly changes in 24 h systolic blood pressure and diastolic blood pressure showed blood pressure reduction throughout 24 h for the renal denervation group. 3 month blood pressure reductions were not significantly different between groups. Medication adherence was about 60% and varied for individual patients throughout the study. No major adverse events were recorded in either group. INTERPRETATION: Renal denervation in the main renal arteries and branches significantly reduced blood pressure compared with sham control with no major safety events. Incomplete medication adherence was common. FUNDING: Medtronic.

Packer, M., B. Claggett, M. P. Lefkowitz, J. J. V. McMurray, J. L. Rouleau, S. D. Solomon and M. R. Zile (2018). “Effect of neprilysin inhibition on renal function in patients with type 2 diabetes and chronic heart failure who are receiving target doses of inhibitors of the renin-angiotensin system: a secondary analysis of the PARADIGM-HF trial.” Lancet Diabetes Endocrinol 6(7): 547-554.

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BACKGROUND: Neprilysin inhibition has favourable effects on experimental diabetic nephropathy. We sought to assess the effects of neprilysin inhibition on the course of renal function in patients with type 2 diabetes. METHODS: In the randomised, double-blind PARADIGM-HF trial, the effects of sacubitril/valsartan (97 mg/103 mg twice daily) were compared with enalapril (10 mg twice daily) in 8399 patients with mild-to-moderate chronic heart failure and systolic dysfunction. In this secondary intention-to-treat analysis, we assessed the change in estimated glomerular filtration rate (eGFR) over a 44-month follow-up period in patients with (n=3784) and those without (n=4615) diabetes. PARADIGM-HF is registered with ClinicalTrials.gov, number NCT01035255. FINDINGS: eGFR decreased by 1.1 mL/min per 1.73 m(2) per year (95% CI 1.0-1.2) in patients without diabetes, but by 2.0 mL/min per 1.73 m(2) per year (1.9-2.1) in those with diabetes (p<0.0001). Compared with patients treated with enalapril, those treated with sacubitril/valsartan had a slower rate of decline in eGFR (-1.3 vs -1.8 mL/min per 1.73 m(2) per year; p<0.0001), and the magnitude of the benefit was larger in patients with versus those without diabetes (difference 0.6 mL/min per 1.73 m(2) per year [95% CI 0.4-0.8] in patients with vs 0.3 mL/min per 1.73 m(2) per year [0.2-0.5] in those without diabetes; pinteraction=0.038). The greater effect of neprilysin inhibition in patients with diabetes could not be explained by the effects of treatment on the course of heart failure or on HbA1c. The incremental benefit of sacubitril/valsartan in patients with diabetes was no longer apparent when changes in eGFR were adjusted for urinary cyclic guanosine monophosphate (p=0.41). INTERPRETATION: In patients in whom the renin-angiotensin system is already maximally blocked, the addition of neprilysin inhibition attenuates the effect of diabetes to accelerate the deterioration of renal function that occurs in patients with chronic heart failure. FUNDING: Novartis.

Wahl, T. S., L. A. Graham, M. S. Morris, J. S. Richman, R. H. Hollis, C. E. Jones, K. M. Itani, T. H. Wagner, H. J. Mull, J. C. Whittle, G. L. Telford, A. K. Rosen, L. A. Copeland, E. A. Burns and M. T. Hawn (2018). “Association Between Preoperative Proteinuria and Postoperative Acute Kidney Injury and Readmission.” JAMA Surg Jul 3: [Epub ahead of print].

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Importance: Proteinuria indicates renal dysfunction and is a risk factor for morbidity among medical patients, but less is understood among surgical populations. There is a paucity of studies investigating how preoperative proteinuria is associated with surgical outcomes, including postoperative acute kidney injury (AKI) and readmission. Objective: To assess preoperative urine protein levels as a biomarker for adverse surgical outcomes. Design, Setting, and Participants: A retrospective, population-based study was conducted in a cohort of patients with and without known preoperative renal dysfunction undergoing elective inpatient surgery performed at 119 Veterans Affairs facilities from October 1, 2007, to September 30, 2014. Data analysis was conducted from April 4 to December 1, 2016. Preoperative dialysis, septic, cardiac, ophthalmology, transplantation, and urologic cases were excluded. Exposures: Preoperative proteinuria as assessed by urinalysis using the closest value within 6 months of surgery: negative (0 mg/dL), trace (15-29 mg/dL), 1+ (30-100 mg/dL), 2+ (101-300 mg/dL), 3+ (301-1000 mg/dL), and 4+ (>1000 mg/dL). Main Outcomes and Measures: Primary outcome was postoperative predischarge AKI and 30-day postdischarge unplanned readmission. Secondary outcomes included any 30-day postoperative outcome. Results: Of 346676 surgeries, 153767 met inclusion criteria, with the majority including orthopedic (37%), general (29%), and vascular procedures (14%). Evidence of proteinuria was shown in 43.8% of the population (trace: 20.6%, 1+: 16.0%, 2+: 5.5%, 3+: 1.6%) with 20.4%, 14.9%, 4.3%, and 0.9%, respectively, of the patients having a normal preoperative estimated glomerular filtration rate (eGFR). In unadjusted analysis, preoperative proteinuria was significantly associated with postoperative AKI (negative: 8.6%, trace: 12%, 1+: 14.5%, 2+: 21.2%, 3+: 27.6%; P < .001) and readmission (9.3%, 11.3%, 13.3%, 15.8%, 17.5%, respectively, P < .001). After adjustment, preoperative proteinuria was associated with postoperative AKI in a dose-dependent relationship (trace: odds ratio [OR], 1.2; 95% CI, 1.1-1.3, to 3+: OR, 2.0; 95% CI, 1.8-2.2) and 30-day unplanned readmission (trace: OR, 1.0; 95% CI, 1.0-1.1, to 3+: OR, 1.3; 95% CI, 1.1-1.4). Preoperative proteinuria was associated with AKI independent of eGFR. Conclusions and Relevance: Proteinuria was associated with postoperative AKI and 30-day unplanned readmission independent of preoperative eGFR. Simple urine assessment for proteinuria may identify patients at higher risk of AKI and readmission to guide perioperative management.

Vogt, D., D. F. Perkins, L. A. Copeland, E. P. Finley, C. S. Jamieson, B. Booth, S. Lederer and C. L. Gilman (2018). “The Veterans Metrics Initiative study of US veterans’ experiences during their transition from military service.” BMJ Open 8(6): e020734.

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PURPOSE: Efforts to promote the health and well-being of military veterans have been criticised for being inadequately informed of veterans’ most pressing needs as they separate from military service, as well as the programmes that are most likely to meet these needs. The current article summarises limitations of the current literature and introduces The Veterans Metrics Initiative (TVMI) study, a longitudinal assessment of US veterans’ well-being and programme use in the first three years after they separate from military service. Veterans were assessed within 3 months of military separation and will complete five additional assessments at 6-month intervals during the subsequent period. PARTICIPANTS: The TVMI study cohort consists of a national sample of 9566 newly separated US veterans that were recruited in the fall of 2016. FINDINGS TO DATE: The TVMI sample includes representation from all branches of service, men and women, and officers and enlisted personnel. Although representative of the larger population on many characteristics, differential response rates were observed for some subgroups, necessitating the development of non-response bias weights. Comparisons between unweighed and weighted results suggest that the weighting procedure adequately adjusts for observed differences. FUTURE PLANS: Analyses are under way to examine veterans’ well-being and programme use in the period following separation after military service, as well as factors associated with poor outcomes. We have also begun to decompose programmes into their core components to facilitate examination of how these components relate to well-being. Once our third data collection is complete, we will examine factors related to different patterns of readjustment over time.