Facutly Peer Reviewed
As you sit down to read this week’s Primecuts, just take a few moments to think about those affected by the tradegy in Haiti. The devastating earthquake that shook the small nation early last week not only affected the nine million inhabitants that call it home but people all over the world, including, as we do live in a global city, our colleagues, neighbors, and patients. As members of the medical community, it is, of course, our inclination to help and though not all of us may be able to make the journey and provide the physical support, there are several other things that we can do. And, as always, thoughts and prayers are always free as Haiti makes its way towards recovery.
First in this week’s Primecuts- a SIGH of relief for those of us who shake at the idea of those darned multiple choice tests. The New York Times reports on a recent study published in the Journal of Applied Psychology that there may be a better way to predict a student’s success as a physician: personality testing. In the study, three psychologists from the United States and Europe analyzed whether extraversion, openness, conscientiousness, agreeableness, and neuroticism- traits which the researchers termed as the “Big Five”- had any significant correlations with medical school performance as judged by attrition rates and grade point averages. The study followed more than 600 students in Belgium where premedical and medical curriculums are combined into one seven year program. As is the case in the United States, the first part of the curriculum centers on acquiring basic science knowledge while the last years are devoted towards clinical practice. Students were asked to take a standardized personality test at the start of the study and analyzed based on their individual personality profiles. Overall, the study found that students who were extraverted, open, and, most of all, conscientious, academically performed better throughout the course of medical school. In contrast, neuroticism was a constant predictor of poor performance and also of attrition. Of note, those who were extraverted struggled early on during the years of classroom work, but excelled when it came time to practice in the clinics. If nothing else, the study provides more evidence that success as a physician can be attributed to more than just test scores! WHEW! [1, 2]
Post-traumatic stress disorder (PTSD) is something commonly often encountered, particularly for those working in a VA setting. A study published in the New England Journal of Medicine reports that in civilians and military personnel with injuries suffered as a result of combat (excluding traumatic brain injury), the use of morphine during early resuscitation and trauma care was associated with a significantly lower risk of developing PTSD. The study included 696 U.S military personnel who were injured during a combat heavy period of 36 months during Operation Iraqi Freedom. Of the 696, 243 received a diagnosis of PTSD within a 1-24 month period and of those, 61% received morphine. The other 453 did not develop PTSD and of those, 76% had received morphine (odds ratio 0.47, p<0.001). The study did have its limitations including a study design that was observational, missing medication data for some patients leading to their exclusion from the analysis, and an analysis that did not address a dose-response relationship between morphine and PTSD, but it did highlight not only the prevalence of PTSD but also of a potential strategy to keep it from occurring.
We all spend time in our clinics counseling patients on the risks of smoking, but what about the risk of smoking cessation? In this week’s Annals of Internal Medicine, researchers, as part of the Atherosclerosis Risk in Communities (ARIC) study, sought find whether smoking cessation, at least acutely, would lead to an increased risk of diabetes owing to cessation related weight gain. The study followed approximately 10,000 middle-aged adults who initially did not have diabetes from 1987 to 1989. In a nine-year followup period, 1254 of these patients developed type 2 diabetes. Those who smoked had an adjusted hazard ratio of incident diabetes of 1.42 (95% CI, 1.2- 1.67). After adjusting for demographics and co-morbidities such as hypertension, hazard ratios of diabetes for those with a history of smoking as compared to those who never smoked were 1.22 for former smokers (those who quit within the first three years of followup), 1.31 for current smokers, and 1.73 for recent quitters (those who quit during years six to nine of followup) showing that, at least in the short term, smoking cessation had the highest risk of developing type 2 diabetes. The study stresses the importance of not only counseling patients on smoking cessation, but also on additionally advocating for other lifestyle modifications such as activity and diet for both the short and long term. 
In an early online publication of The Lancet, researchers in the Platelet Inhibition and Patient Outcomes (PLATO) trial reported more findings to support the use of ticagrelor over clopidogrel in patients with acute coronary syndromes. The use of ticagrelor, a reversible platelet aggregation inhibitor manufactured by Astra Zeneca, was reported to have lower mortality rates than clopidogrel (9.8% vs. 11.7%, p<0.001) in an initial study published in the New England Journal of Medicine in September 2009. In this more recent study, ticagrelor and clopidogrel were compared in patients with ACS who were also planned for subsequent invasive management. Approximately 13,000 patients were randomized to either ticagrelor (180mg loading with 90mg twice a day maintenance) or clopidogrel (300-600mg loading with 75mg maintenance) with aspirin for 6-12 months. The primary composite endpoint (cardiovascular death, myocardial infarction, or stroke), occurred in fewer patients in the ticagrelor group with a total of 569 events versus that in the clopidogrel group with a total of 668 events (hazard ratio 0.84, p=0.0025), leading the researchers to conclude that ticagrelor may be a better option in patients with ACS undergoing invasive strategies. [5, 6]
Lastly, Lancet Neurology reports on the EARLY trial which compares outcomes in patients receiving dipyridamole with aspirin within 24 hours of presenting with symptoms of an acute ischemic stroke or transient ischemic attack versus those who receive dipyridamole after seven days of aspirin monotherapy. In this study, patients in 46 stroke centers in Germany were randomized to either aspirin plus dipyridamole within 24 hours or aspirin monotherapy for seven days with the subsequent addition of dipyridamole for 90 days. At 90 days, patients were contacted by phone and assessed for residual neurologic disability. A primary composite endpoint (non-fatal stroke, TIA, non-fatal myocardial infarction, and major bleeding complications) was also assessed. The study found no significant difference in either outcome. Mild or no disability was reported by 52% of those who received dipyridamole with aspirin within 24 hours versus 56% who received dipyridamole after seven days of aspirin monotherapy (p= 0.45). A total of 28 patients in the former group and 38 patients in the latter reached the primary composite endpoint (hazard ratio 0.73, p=0.2). Thus, the study shows that the early use of dipyridamole is as effective and safe in minimizing neurologic disability as is dipyridamole used after seven days of aspirin monotherapy. 
That’s it for this week’s Primecuts- good luck to all the interns on the in-service exam and remember, personality counts!
Megha Shah is a first year resident at NYU Medical Center
Peer Reviewed by Judith Brenner, MD Associate Editor, Clinical Correlations
Picture of Dr. Martin Luther King courtesy of Wikimedia Commons
1. Chen, PW. Do You Have the “Right Stuff” to be a Doctor? New York Times. Jan 14, 2010
2. LieLiveLievens F, Ones DS, & Dilchert S. Personality Scale Validities Increase Throughout Medical School. Journal of Applied Psychology. Nov 2009; 94 (6): 1514-1535
3. Holbrook TL, Galarneau MR, Dye JL et al. Morphine Use After Combat Injury in Iraq and Post-Traumatic Stress Disorder. The New England Journal of Medicine. Jan 2010; 362 (2): 110-117
4. Yeh HC, Duncan BB, Schmidt MI et al. Smoking, Smoking Cessation, and Risk for Type 2 Diabetes Mellitus. Annals of Internal Medicine. Jan 2010; 152 (1): 10-17
5. Cannon CP, Harrington RA, James S et al. Comparison of Ticagrelor with Clopidogrel in Patients with a Planned Invasive Strategy for Acute Coronary Syndromes (PLATO): A Randomized Double-Blind Study. Lancet. Early online publication. January 14, 2010
6. Wallentin L, Becker RC, Budaj A et al. Ticagrelor versus Clopidogrel in Patients with Acute Coronary Syndromes. The New England Journal of Medicine. Sept 2009; 361 (11): 1045-1057
7. Dengler R, Diener HC, Schwartz A et al. Early Treatment with Aspirin Plus Extended Release Dipyridamole for Transient Ischemic Attack or Ischemic Stroke within 24H of Symptom Onset (EARLY trial): a Randomized, Open-Label, Blinded- Endpoint Trial. Lancet Neurology. Early online publication, January 8, 2010