Month: June 2020

Week 52 – Symptom-Triggered Benzodiazepines in Alcohol Withdrawal

“Symptom-Triggered vs Fixed-Schedule Doses of Benzodiazepine for Alcohol Withdrawal”

Arch Intern Med. 2002 May 27;162(10):1117-21. [free full text]
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Treatment of alcohol withdrawal with benzodiazepines has been the standard of care for decades. However, in the 1990s, benzodiazepine therapy for alcohol withdrawal was generally given via fixed doses. In 1994, a double-blind RCT by Saitz et al. demonstrated that symptom-triggered therapy based on responses to the CIWA-Ar scale reduced treatment duration and the amount of benzodiazepine used relative to a fixed-schedule regimen. This trial had little immediate impact in the treatment of alcohol withdrawal. The authors of the 2002 double-blind RCT sought to confirm the findings from 1994 in a larger population that did not exclude patients with a history of seizures or severe alcohol withdrawal.

The trial enrolled consecutive patients admitted to the inpatient alcohol treatment units at two European universities (excluding those with “major cognitive, psychiatric, or medical comorbidity”) and randomized them to treatment with either scheduled placebo (30mg q6hrs x4, followed by 15mg q6hrs x8) with additional PRN oxazepam 15mg for CIWA score 8-15 and 30mg for CIWA score > 15 or to treatment with scheduled oxazepam (30mg q6hrs x4, followed by 15mg q6hrs x8) with additional PRN oxazepam 15mg for CIWA score 8-15 and 30mg for CIWA score > 15.

The primary outcomes were cumulative oxazepam dose at 72 hours and duration of treatment with oxazepam. Subgroup analysis included the exclusion of symptomatic patients who did not require any oxazepam. Secondary outcomes included incidence of seizures, hallucinations, and delirium tremens at 72 hours.

Results:
117 patients completed the trial. 56 had been randomized to the symptom-triggered group, and 61 had been randomized to the fixed-schedule group. The groups were similar in all baseline characteristics except that the fixed-schedule group had on average a 5-hour longer interval since last drink prior to admission. While only 39% of the symptom-triggered group actually received oxazepam, 100% of the fixed-schedule group did (p < 0.001). Patients in the symptom-triggered group received a mean cumulative dose of 37.5mg versus 231.4mg in the fixed-schedule group (p < 0.001). The mean duration of oxazepam treatment was 20.0 hours in the symptom-triggered group versus 62.7 hours in the fixed-schedule group. The group difference in total oxazepam dose persisted even when patients who did not receive any oxazepam were excluded. Among patients who did receive oxazepam, patients in the symptom-triggered group received 95.4 ± 107.7mg versus 231.4 ± 29.4mg in the fixed-dose group (p < 0.001). Only one patient in the symptom-triggered group sustained a seizure. There were no seizures, hallucinations, or episodes of delirium tremens in any of the other 116 patients. The two treatment groups had similar quality-of-life and symptom scores aside from slightly higher physical functioning in the symptom-triggered group (p < 0.01). See Table 2.

Implication/Discussion:
Symptom-triggered administration of benzodiazepines in alcohol withdrawal led to a six-fold reduction in cumulative benzodiazepine use and a much shorter duration of pharmacotherapy than fixed-schedule administration. This more restrictive and responsive strategy did not increase the risk of major adverse outcomes such as seizure or DTs and also did not result in increased patient discomfort.

Overall, this study confirmed the findings of the landmark study by Saitz et al. from eight years prior. Additionally, this trial was larger and did not exclude patients with a prior history of withdrawal seizures or severe withdrawal. The fact that both studies took place in inpatient specialty psychiatry units limits their generalizability to our inpatient general medicine populations.

Why the initial 1994 study did not gain clinical traction remains unclear. Both studies have been well-cited over the ensuing decades, and the paradigm has shifted firmly toward symptom-triggered benzodiazepine regimens using the CIWA scale. While a 2010 Cochrane review cites only the 1994 study, Wiki Journal Club and 2 Minute Medicine have entries on this 2002 study but not on the equally impressive 1994 study.

Further Reading/References:
1. “Individualized treatment for alcohol withdrawal. A randomized double-blind controlled trial.” JAMA. 1994.
2. Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar)
3. Wiki Journal Club
4. 2 Minute Medicine
5. “Benzodiazepines for alcohol withdrawal.” Cochrane Database Syst Rev. 2010

Summary by Duncan F. Moore, MD

Image Credit: VisualBeo, CC BY-SA 3.0, via Wikimedia Commons

Week 51 – LOTT

“A Randomized Trial of Long-Term Oxygen for COPD with Moderate Desaturation”

by the Long-Term Oxygen Treatment Trial (LOTT) Research Group

N Engl J Med. 2016 Oct 27;375(17):1617-1627. [free full text]
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The long-term treatment of severe resting hypoxemia (SpO2 < 89%) in COPD with supplemental oxygen has been a cornerstone of modern outpatient COPD management since its mortality benefit was demonstrated circa 1980. Subsequently, the utility of supplemental oxygen in COPD patients with moderate resting daytime hypoxemia (SpO2 89-93%) was investigated in trials in the 1990s; however, such trials were underpowered to assess mortality benefit. Ultimately, the LOTT trial was funded by the NIH and Centers for Medicare and Medicaid Services (CMS) primarily to determine if there was a mortality benefit to supplemental oxygen in COPD patients with moderate hypoxemia as well to analyze as numerous other secondary outcomes, such as hospitalization rates and exercise performance.

The LOTT trial was originally planned to enroll 3500 patients. However, after 7 months the trial had randomized only 34 patients, and mortality had been lower than anticipated. Thus in late 2009 the trial was redesigned to include broader inclusion criteria (now patients with exercise-induced hypoxemia could qualify) and the primary endpoint was broadened from mortality to a composite of time to first hospitalization or death.

The revised LOTT trial enrolled COPD patients with moderate resting hypoxemia (SpO2 89-93%) or moderate exercise-induced desaturation during the 6-minute walk test (SpO2 ≥ 80% for ≥ 5 minutes and < 90% for ≥ 10 seconds). Patients were randomized to either supplemental oxygen (24-hour oxygen if resting SpO2 89-93%, otherwise oxygen only during sleep and exercise if the desaturation occurred only during exercise) or to usual care without supplemental oxygen. Supplemental oxygen flow rate was 2 liters per minute and could be uptitrated by protocol among patients with exercise-induced hypoxemia. The primary outcome was time to composite of first hospitalization or death. Secondary outcomes included hospitalization rates, lung function, performance on 6-minute walk test, and quality of life.

368 patients were randomized to the supplemental-oxygen group and 370 to the no-supplemental-oxygen group. Of the supplemental-oxygen group, 220 patients were prescribed 24-hour oxygen support, and 148 were prescribed oxygen for use during exercise and sleep only. Median duration of follow-up was 18.4 months. Regarding the primary outcome, there was no group difference in time to death or first hospitalization (p = 0.52 by log-rank test). See Figure 1A. Furthermore, there were no treatment-group differences in the primary outcome among patients of the following pre-specified subgroups: type of oxygen prescription, “desaturation profile,” race, sex, smoking status, SpO2 nadir during 6-minute walk, FEV1, BODE  index, SF-36 physical-component score, BMI, or history of anemia. Patients with a COPD exacerbation in the 1-2 months prior to enrollment, age 71+ at enrollment, and those with lower Quality of Well-Being Scale score at enrollment all demonstrated benefit from supplemental O2, but none of these subgroup treatment effects were sustained when the analyses were adjusted for multiple comparisons. Regarding secondary outcomes, there were no treatment-group differences in rates of all-cause hospitalizations, COPD-related hospitalizations, or non-COPD-related hospitalizations, and there were no differences in change from baseline measures of quality of life, anxiety, depression, lung function, and distance achieved in 6-minute walk.

The LOTT trial presents compelling evidence that there is no significant benefit, mortality or otherwise, of oxygen supplementation in patients with COPD and either moderate hypoxemia at rest (SpO2 > 88%) or exercise-induced hypoxemia. Although this trial’s substantial redesign in its early course is noted, the trial still is our best evidence to date about the benefit (or lack thereof) of oxygen in this patient group. As acknowledged by the authors, the trial may have had significant selection bias in referral. (Many physicians did not refer specific patients for enrollment because “they were too ill or [were believed to have benefited] from oxygen.”) Another notable limitation of this study is that nocturnal oxygen saturation was not evaluated. The authors do note that “some patients with COPD and severe nocturnal desaturation might benefit from nocturnal oxygen supplementation.”

For further contemporary contextualization of the study, please see the excellent post at PulmCCM from 11/2016. Included in that post is a link to an overview and Q&A from the NIH regarding the LOTT study.

References / Additional Reading:
1. PulmCCM, “Long-term oxygen brought no benefits for moderate hypoxemia in COPD”
2. LOTT @ 2 Minute Medicine
3. LOTT @ ClinicalTrials.gov
4. McDonald, J.H. 2014. Handbook of Biological Statistics (3rd ed.). Sparky House Publishing, Baltimore, Maryland.
5. Centers for Medicare and Medicaid Services, “Certificate of Medical Necessity CMS-484– Oxygen”
6. Ann Am Thorac Soc. 2018 Dec;15(12):1369-1381. “Optimizing Home Oxygen Therapy. An Official American Thoracic Society Workshop Report.”

Summary by Duncan F. Moore, MD

Image Credit: Patrick McAleer, CC BY-SA 2.0 UK, via Wikimedia Commons

Week 50 – PARADIGM-HF

“Angiotensin-Neprilysin Inhibition versus Enalapril in Heart Failure”

N Engl J Med. 2014 Sep 11;371(11):993-1004. [free full text]
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Background:
Thanks to the CONSENSUS and SOLVD trials, angiotensin-converting enzyme (ACE) inhibitors have been a cornerstone of the treatment of heart failure with reduced ejection fraction (HFrEF) for years. Neprilysin is a neutral endopeptidase that degrades several peptides, including natriuretic peptides, bradykinin, and adrenomedullin. Inhibiting neprilysin increases levels of these substances and thus counteracts the neurohormonal overactivation of heart failure (which would otherwise lead to vasoconstriction, sodium retention, and maladaptive remodeling). Prior experimental data has demonstrated that, in terms of cardiovascular outcomes, neprilysin inhibition with an ARB is superior to ARB monotherapy. However, a clinical trial of concurrent neprilysin-inhibitor and ACE inhibitor therapy resulted in unacceptably high rates of serious angioedema. This study sought to show improved cardiac and mortality outcomes with neprilysin inhibition plus an ARB when compared to enalapril alone.

The study enrolled adults with NYHA class II, III, or IV heart failure, LVEF ≤ 35%, and BNP ≥ 150 or NT-proBNP ≥ 600. Pertinent exclusion criteria included symptomatic hypotension, SBP < 100mmHg at screening or 95mmHg at randomization, eGFR < 30 or decrease in eGFR by 25% between screening and randomization, K+ > 5.2, or history of angioedema/side effects to ACE inhibition or ARBs. Patients were randomized to treatment with either sacubitril/valsartan 200mg BID or to enalapril 10mg BID. (Screened patients were initially given sacubitril/valsartan followed by enalapril in single blinded run-in phases in order to ensure similar tolerance of the drugs prior to randomization.) The primary outcome was a composite of death from cardiovascular causes or first hospitalization for heart failure. Selected secondary outcomes included: 1) change from baseline in the clinical summary score of the Kansas City Cardiomyopathy Questionnaire (KCCQ), 2) time to new-onset atrial fibrillation, and 3) time to first occurrence of decline in renal function.

Results:
4187 patients were randomized to the sacubitril/valsartan group, and 4212 were randomized to the enalapril group.

The primary endpoint (composite death due to cardiovascular causes or first hospitalization for HF) occurred in 914 patients (21.8%) in the sacubitril/valsartan group and 1117 patients (26.5%) in the enalapril group (p < 0.001; NNT = 21). Death due to cardiovascular causes occurred 558 times in the sacubitril/valsartan group and 693 times in the enalapril group (13.3% vs. 16.5%, p < 0.001; NNT = 31). Hospitalization for heart failure occurred (at least once) 537 times in the sacubitril/valsartan group and 658 times in the enalapril group (12.8% vs. 15.6%, p < 0.001; NNT = 36).

Regarding secondary outcomes, the mean change in KCCQ score was a reduction of 2.99 points (i.e. a worsening of symptoms) in the sacubitril/valsartan group versus a reduction of 4.63 points in the enalapril group (p = 0.001). There was no significant group difference in time to new-onset atrial fibrillation or time to diminished renal function.

Regarding safety outcomes, patients in the sacubitril/valsartan group were more likely to have symptomatic hypotension compared to patients in the enalapril group (14.0% vs. 9.2%; p < 0.001; NNH = 21). However, patients in the enalapril group were more likely to have cough, serum creatinine ≥ 2.5, or potassium ≥6.0 compared to sacubitril/valsartan (p value varies, all significant). There was no group difference in rates of angioedema (p = 0.13).

Implication/Discussion:
In patients with HFrEF, inhibition of both angiotensin II and neprilysin with sacubitril/valsartan significantly reduced the risk of cardiovascular death or hospitalization for heart failure when compared to treatment with enalapril alone.

This study had several strengths. The treatment with sacubitril/valsartan was compared to treatment with a dose of enalapril that had previously been shown to reduce mortality when compared with placebo. Furthermore, the study used a run-in phase to ensure that patients could tolerate an enalapril dose that had previously been shown to reduce mortality. Finally, more patients in the enalapril group than in the sacubitril/valsartan group stopped the study drug due to adverse effects (12.3% vs. 10.7%, p = 0.03).

This study ushered in a new era in heart failure management and added a new medication class – Angiotensin Receptor-Neprilysin Inhibitors or ARNIs – to the arsenal of available heart failure drugs. Entresto (sacubitril/valsartan), the ARNI posterchild, has been advertised widely over the past several years. However, clinical use so far has been lower than expected (see here).

The 2017 ACC/AHA update to the guidelines for management of symptomatic HFrEF states that primary inhibition of the renin-angiotensin system with an ARNI in conjunction with evidence-based beta blockade and aldosterone antagonism is a Class I recommendation (Level B evidence). However, it does not favor this regimen over the Level-A-evidence regimens of an ARB or ACE inhibitor substituted for the ARNI. Yet the new guidelines also state that patients who have chronic symptomatic HFrEF of NYHA class II or III and tolerate an ACE inhibitor or ARB should substitute an ARNI for the ACE inhibitor or ARB in order to further reduce morbidity and mortality (Class I recommendation, level B evidence). See pages 15 and 17 here to read the details.

Bottom line: Among patients with symptomatic HFrEF, treatment with an ARNI reduces cardiovascular mortality and HF hospitalizations when compared to treatment with enalapril. Due to this study’s impact, the use of ARNIs is now a Class I recommendation by the 2017 ACC/AHA guidelines for the treatment of HFrEF. Despite its higher cost, the use of sacubitril/valsartan appears to be cost-effective in terms of QALYs gained.

Further Reading/References:
1. Wiki Journal Club
2. 2 Minute Medicine
3. ACC/AHA 2017 Focused Update for Guideline Management of Heart Failure.
4. CardioBrief, “After Slow Start Entresto Is Poised For Takeoff.”
5. PARAGON-HF @ ClinicalTrials.gov
6. McMurray et al., “Cost-effectiveness of sacubitril/valsartan in the treatment of heart failure with reduced ejection fraction.” Heart, 2017.

Summary by Patrick Miller, MD

Week 49 – Donor-Feces Infusion for Recurrent C. difficile

“Duodenal Infusion of Donor Feces for Recurrent Clostridium difficile”

N Engl J Med. 2013 Jan 31;368(5):407-15. [free full text]
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Clostridioides (formerly Clostridium) difficile infection (CDI) is a common, increasingly prevalent, and increasingly recurrent disease. As discussed in the 2017-2018 Academic Year Week 43 post, the IDSA/SHEA guidelines published March 2018 now list vancomycin PO as first line treatment for initial, non-severe CDI. These guidelines also list fecal microbiota transplantation (FMT) as an option for treatment of a second or subsequent recurrence of CDI. FMT received a rating of “Strong [recommendation] / Moderate [level of evidence]” for this indication thanks to this 2013 trial by van Nood et al. – the first prospective RCT to compare antibiotic therapy to FMT in recurrent CDI.

This single-academic-center (Netherlands), open-label, randomized controlled trial compared three regimens for the treatment of recurrent CDI. One treatment arm received vancomycin 500mg PO QID x4-5 days followed by bowel lavage and then infusion of donor feces through nasoduodenal tube, another treatment arm received a standard 14-day vancomycin 500mg PO QID regimen, and the final treatment arm received a standard 14-day vancomycin regimen with additional bowel lavage on day 4 or 5. The primary endpoint was cure without relapse by 10 weeks.

43 patients were randomized prior to the termination of the trial due to the markedly higher rates of recurrent CDI among patients who did not receive FMT. Regarding the primary outcome, 13 (81%) of the FMT group were cured after the first infusion (and remained so) at 10 weeks, whereas resolution of CDI occurred in only 4 (31%) of the vancomycin-alone group and in only 3 (23%) of the vancomycin + bowel lavage group (p < 0.001 for both pairwise comparisons vs. FMT).

In this randomized controlled trial, fecal microbiota transplantation was superior to both vancomycin and vancomycin plus bowel lavage in the cure of recurrent Clostridioides difficile infection. Although this trial was small, its effect was enormous. As mentioned above, FMT is now recommended by guidelines for the treatment of multiply-recurrent CDI. FMT has been the subject of numerous published and ongoing trials, including this notable 2017 study by Kao et al. that demonstrated noninferiority of FMT delivered via oral capsules versus “conventional” colonoscopic delivery.

Further Reading/References:
1. Wiki Journal Club
2. 2 Minute Medicine
3. 2017 Update to IDSA/SHEA Clinical Practice Guidelines for Clostridium difficile Infection
4. Kao et. al, “Effect of Oral Capsule- vs Colonoscopy-Delivered Fecal Microbiota Transplantation on Recurrent Clostridium difficile Infection.” JAMA. 2017;318(20):1985-1993.
5. IDSA, “Fecal Microbiota Transplantation”
6. Food and Drug Administration, “Enforcement Policy Regarding Investigational New Drug Requirements for Use of Fecal Microbiota for Transplantation to Treat Clostridium difficile Infection Not Responsive to Standard Therapies”

Summary by Duncan F. Moore, MD

Image Credit: CDC/ Lois S. Wiggs (PHIL #6260), Public Domain, via Wikimedia Commons