Primecuts – This Week In The Journals

December 23, 2013

By Preethi Prasad, MD

Peer Reviewed

This week, Christmas is finally on its way, and the city is alive with festive cheer. Children are excitedly anticipating a visit from Santa Claus, while adults are scrambling to do last-minute Christmas shopping. In addition to sipping eggnog and enjoying the holidays, many Americans are also using this time to focus on their health as Monday, December 23rd is the deadline for most to sign up for health insurance that starts on January 1st.

For some people, traveling home for Christmas requires a Trans-Atlantic flight, and it is important to be aware of the increased risk of pulmonary embolism (PE) from prolonged immobility. Computed tomographic pulmonary angiography (CTPA) is the primary imaging modality used to diagnose PE. An article in Chest explored the utility of using CTPA to establish alternative diagnoses such as pneumonia, pleural effusion, tumor, atelectasis, bronchiolitis, pericardial effusion, chronic obstructive pulmonary disease (COPD), and heart failure [1]. The 203 patients in the study were all classified as likely to have PE based on Wells criteria, and treating physicians evaluated the patients and considered alternative diagnoses prior to imaging. Ultimately after imaging, 39 patients (19%) were diagnosed with PE, 61 (30%) had normal CTPA, and alternative diagnoses were found in 88 (43%). These alternative diagnoses included pneumonia, pleural effusions, and tumors. In 56 (28%) of these 88, the alternative diagnoses were thought to account for the initial presenting signs and symptoms. 19 of the 56 (8.8%) had findings that were unsuspected prior to imaging. In 11 patients (5.4%), the abnormalities on imaging resulted in further diagnostic testing, such as bronchoscopy, thoracentesis, sputum culture, or magnetic resonance imaging. In 10 patients (4.9%), the results from the imaging had therapeutic consequences, specifically antibiotics, diuretics, or corticosteroids. Despite the lack of guidelines on scanning patients with a low pretest probability for PE, clinicians often use CTPA in the hope that it will help find an alternative diagnosis. This study advises against the liberal use of imaging due to the relatively low yield of therapeutic consequences. As clinicians, we should primarily use CTPA in patients with a sufficiently high pretest probability for PE and not to establish alternative diagnoses.

Under the Affordable Care Act, uninsured patients with pre-existing conditions, such as asthma and COPD, will no longer be denied coverage. An article in Chest looked into the risk of pneumonia and lower respiratory tract infections (LRTI) in asthma patients on inhaled corticosteroids (ICS) [2]. The study enrolled 6857 patients with pneumonia and LRTI. The results showed that fluticasone propionate was associated with a higher risk of pneumonia or LRTI (odds ratio [OR] 1.20 95% confidence interval [CI] 1.06-1.35. After adjusting for confounding variables, 1.7% of the patients were prescribed high doses of ICS (>1000 ug), and these patients were 2.04 times more likely to have pneumonia or LRTI (95% CI 1.59-2.64) with the effect being strongest for pneumonia. This study will be useful in practice, as we should be vigilant of the doses of ICS and use the lowest dose necessary to control a patient’s symptoms due to the secondary risk of developing pneumonia and LRTI .

Ventilator-associated pneumonia (VAP) results in prolonged intensive care unit stays and a significant economic burden, costing several thousands of health care dollars per patient [3]. A systematic review in Chest explored the appropriate duration of antibiotic regimens in patients with ventilator-associated pneumonia with the hypothesis that using shorter regimens may decrease resistance and adverse events [4]. Ultimately, four randomized control trials were used in the study, encompassing a total of 883 patients with VAP who were either treated with a short course of antibiotics (7-8 days) or a long course (10-15 days). The primary outcomes were 28-day mortality, antibiotic-free days, and relapses. The results showed that there was no difference in mortality in the two groups (fixed effect model [FEM] OR=1.20; 95% CI, 0.84-1.72 P=0.32). Although there was no statistically significant difference in relapses amongst the two treatment arms, there was a trend to lower relapses in the longer treatment group (FEM: OR=1.67 95% CI, 0.99-2.83 P=0.06). The primary conclusion from the study was that there was no difference in mortality between the short and long treatment arms. Of note, the relapses in the studies were mostly due to nonfermenting gram negative bacilli (NFGNB), for which relapses are common [5]. The article suggests monitoring serum biomarkers such as procalcitonin in conjunction with short-course regimens, particularly in patients with NFGNB infections. Although there was no difference in mortality, in practice, it is still important to balance the pros and cons of the duration of antibiotics until more definitive data becomes available through targeted trials.

With the advent of affordable health care, it is expected that there will be more elective noncardiac surgeries and procedures performed in an aging population with cardiac comorbidities. In Chest, a recent systematic review was published describing clinical practice guidelines on the perioperative management of antiplatelet therapy in patients with stents who require noncardiac surgery [6]. Managing patients with coronary stents who require noncardiac surgery is particularly challenging due to the need to balance the risk of major adverse cardiovascular events (MACE) against the risk of bleeding. Overall, patients with coronary stents have an 8-10% risk of developing MACE during noncardiac surgery compared to 1-5% in the general population without stents [7]. Ultimately, 11 studies were included in the review, but there were no Grade 1A or 1B recommendations from any of the articles. The guidelines advised delaying elective noncardiac surgery for at least 4 weeks after bare-metal stent placement and 6 months after drug-eluting stent placement. Aspirin should be continued whenever possible, and both aspirin and clopidogrel should be continued for urgent procedures. If clopidogrel were to be discontinued due to increased bleeding risk, 8 of the studies recommended the continuation of aspirin. If aspirin and/or clopidogrel were to be discontinued prior to surgery, four articles recommended stopping the antiplatelet agents at least 5 days prior to surgery, but there was no true consensus. Three studies suggested resuming antiplatelet therapy within 24 hours after surgery. There was no true consensus about the role for bridging agents amongst the 11 articles. The clinical implications of this article are the following: it is recommended to defer elective noncardiac surgery for at least 4 weeks after bare-metal stent placement and 6 months after drug-eluting stent placement and continue aspirin perioperatively in most patients and dual antiplatelet therapy in high risk patients unless precluded by high bleeding risk. There is still no established consensus on when to discontinue the medications or when to resume them after surgeries. The article highlights the lack of high quality evidence in this area and the need for further randomized control trials and cohort studies.

 

Additional Articles:

1. This study was a randomized control trial that investigated whether oral high-dose multivitamins and minerals would reduce cardiovascular events in patients after myocardial infarction. The primary endpoints were mortality, recurrent MI, stroke, angina leading to hospitalization, and coronary revascularization. Ultimately, the results showed that vitamins and minerals did not statistically significantly reduce these events.

Lamas GA, Boineau R, Goertz C, et al. Oral High-Dose Multivitamins and Minerals After Myocardial Infarction: A Randomized Trial. Annals of Internal Medicine. 2013 Dec;159(12):797-805. http://annals.org/article.aspx?articleid=1789248

 

2. This study was also a randomized control trial that explored the use of multivitamins in improving cognitive function in men. The study involved 5947 male physicians above the age of 65. Ultimately, there were no statistically significant cognitive benefits from multivitamin supplementation that were shown.

Grodstein F, O’Brien J, Kang JH, et al. Long-Term Multivitamin Supplementation and Cognitive Function in Men: A Randomized Trial. Annals of Internal Medicine. 2013 Dec;159(12):806-814. http://annals.org/article.aspx?articleid=1789250

 

3. The ROSE acute heart failure randomized trial investigated the use of low-dose dopamine and nesiritide in patients with acute heart failure to enhance decongestion and preserve renal function. With respect to 72-hour cumulative urine volume, cystatin C level, and decongestion, both medications were shown to have no statistically significant effect compared to placebo.

Chen HH, Anstrom KJ, Givertz MM et al. Low-dose dopamine or low-dose nesiritide in acute heart failure with renal dysfunction: the ROSE acute heart failure randomized trial. JAMA. 2013 Dec 18;310(23):2533-43. http://jama.jamanetwork.com/article.aspx?articleid=1779722

 

Dr. Preethi Prasad is a 2nd year resident in internal medicine, at NYU Langone Medical Center

Peer reviewed by Dr. Matthew Vorsanger, Associate Editor, Clinical Correlations


References

1. Van Es J, Douma RA, Schreuder SM, et al. Clinical Impact of Findings Supporting an Alternative Diagnosis on CT Pulmonary Angiography in Patients With Suspected Pulmonary Embolism. Chest. 2013 Dec 1;144(6):1893-9. http://journal.publications.chestnet.org/article.aspx?articleid=1733328

2. McKeever T, Harrison TW, Hubbard R, Shaw D. Inhaled corticosteroids and the risk of pneumonia in people with asthma: a case-control study. Chest. 2013 Dec 1;144(6):1788-94. http://journal.publications.chestnet.org/article.aspx?articleid=1733331

3. Falagas ME, Avgeri SG, Matthaiou DK , et al. Short- versus long-duration antimicrobial treatment for exacerbations of chronic bronchitis: a meta-analysis. J Antimicrob Chemother . 2008 ; 62 ( 3 ): 442-450. http://jac.oxfordjournals.org/content/62/3/442.long

4. Dimopoulos G, Poulakou G, Pneumatikos IA, et al. Short- vs Long-Duration Antibiotic Regimens for Ventilator-Associated Pneumonia: A Systematic Review and Meta-analysis. Chest. 2013 Dec 1;144(6):1759-67. http://journal.publications.chestnet.org/article.aspx?articleid=1698747

5. Hedrick TL, McElearney ST, Smith RL, et al. Duration of antibiotic therapy for ventilator associated pneumonia caused by non-fermentative gram negative bacilli. Surg Infect (Larchmt). 2007; 8 (6): 589 – 597. http://online.liebertpub.com/doi/abs/10.1089/sur.2006.021

6. Darvish-Kazem S, Gandhi M, Marcucci M, et al. Perioperative management of antiplatelet therapy in patients with a coronary stent who need noncardiac surgery: a systematic review of clinical practice guidelines. Chest. 2013 Dec 1;144(6):1848-56. http://journal.publications.chestnet.org/article.aspx?articleid=1725196

7. Iakovou I, Schmidt T, Bonizzoni E, et al . Incidence, predictors, and outcome of thrombosis after successful implantation of drug-eluting stents. JAMA. 2005; 293 (17): 2126 – 2130. http://jama.jamanetwork.com/article.aspx?doi=10.1001/jama.293.17.2126

 

 

 

 

 

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