Thursday, September 25, 2014

American College of Cardiology removes one of its choosing wisely recommendations in light of recent evidence

From an ACC news release:

In response to new science showing that complete revascularization of all significantly blocked arteries leads to better outcomes in some heart attack patients, the American College of Cardiology has withdrawn its Choosing Wisely recommendation that patients and caregivers examine whether this practice is truly necessary.

We've learned well the lessons against hasty adoption following early evidence. This is the flip side. We must be very cautious about putting something on the “do not” list. I think the campaign has been a little hasty in some of its recommendations.

Via Cardiobrief.

Cardiac involvement in mixed connective tissue disease

From a recent review:

616 patients were included. Prevalence of cardiac involvement varied from 13% to 65% depending on patient selection and method used for detection. Pericarditis was the most common cardiac diagnosis with a prevalence of 30% and 43% in two prospective studies. Non-invasive cardiac tests, including electrocardiogram and echocardiogram, detected subclinical cardiac abnormalities in 6%–38% of patients. These abnormalities included conduction abnormalities, pericardial effusion and mitral valve prolapse. Diastolic dysfunction and accelerated atherosclerosis were well-documented in a case–control study. Three prospective studies revealed an overall mortality of 10.4% over the period of follow-up of 13–15 years. 20% of the mortality was directly attributable to cardiac cause.

Cardiac involvement was common among patients with MCTD though the involvement was often clinically inapparent. Non-invasive cardiac tests might have a role for subclinical disease screening for early diagnosis and timely treatment as cardiac involvement was one of the leading causes of mortality.

Wednesday, September 24, 2014

Cyclobenzaprine (Flexeril) overdose: is it the same as with a tricyclic?

According to this post (with references to back it up) at Academic Life in Emergency Medicine it's not nearly as bad. The anticholinergic toxidrome is present but not the life threatening cardiac arrhythmias or refractory seizures. (I wouldn't discount the possibility of the really nasty stuff if the OD is large).

Exercise your brain and delay cognitive impairment

From a JAMA Clinical Trials Update.

Monday, September 22, 2014

Adjunctive antiarrhythmic therapy for patients with AICDs

---to reduce the need for device treatment (appropriate shocks) as well as inappropriate shocks. Nice review here and free full text via Medscape.

Vitamin D as hormone replacement therapy

Via Medpage Today.

Ondansetron and arrhythmia risk

Ondansetron (Zofran) has the potential to prolong repolarization and the labeling has a warning to that effect. In this review an extensive data search found a low risk of arrhythmia. The main concern is with repeated intravenous doses in patients with other risk factors. Via Medpage Today.

Tuesday, September 16, 2014

Guideline adherence and outcomes in heart failure

Here's an interesting study from the International Journal of Cardiology:

Data on ambulatory patients (2006–2010) with CHF and reduced ejection fraction (HF-REF) from the Austrian Heart Failure Registry (HIR Austria) were analysed. One-year clinical data and long-term follow-up data until all-cause death or data censoring were available for 1014 patients (age 65 [55–73], male 75%, NYHA class I 14%, NYHA II 56%, NYHA III/IV 30%). A guideline adherence indicator (GAI [0–100%]) was calculated for each patient at baseline and after 12 ± 3 months that considered indications and contraindications for ACE-I/ARB, beta blockers, and MRA. Patients were considered ΔGAI-positive if GAI improved to or remained at high levels (greater than of equal to 80%). ΔGAI50+ positivity was ascribed to patients achieving a dose of greater than or equal to 50% of suggested target dose.

Improvements in GAI and GAI50+ were associated with significant improvements in NYHA class and NT-proBNP (1728 [740–3636] to 970 [405–2348]) (p less than 0.001). Improvements in GAI50+, but not GAI, were independently predictive of lower mortality risk (HR 0.55 [95% CI 0.34–0.87; p = 0.01]) after adjustment for a large variety of baseline parameters and hospitalisation for heart failure during follow-up.

Improvement in guideline adherence with particular emphasis on dose escalation is associated with a decrease in long-term mortality in ambulatory HF-REF subjects surviving one year after registration.

This is one explanation of why heart failure performance measures are not valid. They do not address titration of medications to goal.

Sunday, September 14, 2014

Limitations of the urine eosinophil test

From a retrospective study on the test characteristics for the diagnosis of acute interstitial nephritis (AIN):

This study identified 566 patients with both a UE test and a native kidney biopsy performed within a week of each other. Of these patients, 322 were men and the mean age was 59 years. There were 467 patients with pyuria, defined as at least one white cell per high-power field. There were 91 patients with AIN (80% was drug induced). A variety of kidney diseases had UEs. Using a 1% UE cutoff, the comparison of all patients with AIN to those with all other diagnoses showed 30.8% sensitivity and 68.2% specificity, giving positive and negative likelihood ratios of 0.97 and 1.01, respectively. Given this study’s 16% prevalence of AIN, the positive and negative predictive values were 15.6% and 83.7%, respectively. At the 5% UE cutoff, sensitivity declined, but specificity improved. The presence of pyuria improved the sensitivity somewhat, with a decrease in specificity. UEs were no better at distinguishing AIN from acute tubular necrosis compared with other kidney diseases.
Conclusions UEs were found in a variety of kidney diseases besides AIN. At the commonly used 1% UE cutoff, the test does not shift pretest probability of AIN in any direction. Even at a 5% cutoff, UEs performed poorly in distinguishing AIN from acute tubular necrosis or other kidney diseases.

Via Renal Fellow Network.

Saturday, September 13, 2014

Non-surgical management of appendicitis?

From a recent study:

During this 4-year study, we enrolled 26 elderly patients who initially received antibiotic therapy. Of these, 3 were suspected to have complicated appendicitis. Antibiotic therapy consisted of second-generation cephalosporin and metronidazole that was administered for 4 days with a 24 h fasting period. We evaluated the rates of treatment failure and recurrence.

Mean age was 83.5 years and 57.7% (15/26) of patients had comorbidities. One patient (4.8%) failed to respond to antibiotic therapy and underwent subsequent appendectomy. During the median follow-up period of 17 months, 5 patients (20%) experienced recurrence; 3 underwent appendectomy and two received a new course of antibiotics.

Antibiotic therapy without surgery may be a safe and an effective treatment for appendicitis in selective patients aged greater than or equal to 80 years. This is a good treatment option in patients with high operative risk.

Via Hospital Medicine Virtual Journal Club.

Sunday, September 07, 2014

Predicting spontaneous reperfusion from the initial ECG

From a recent paper in AJC:

Inversion of the T waves (T−) in electrocardiographic leads with ST-segment elevation after the initiation of reperfusion therapy is considered a sign of reperfusion. However, the significance of T− on presentation before the initiation of reperfusion therapy is unclear. The aim of this study was to assess whether T− on presentation predicts patency of the infarct-related artery in patients with acute ST-segment elevation myocardial infarctions (STEMIs)...Patency of the infarct-related artery (Thrombolysis In Myocardial Infarction [TIMI] flow grades 2 and 3) was seen in 64.3% of the patients in the T− group compared with only 31.2% in the T+/− group and 19.0% in the T+ group (p less than 0.001). Among patients with anterior STEMI, patency of the infarct-related artery was seen in all 7 patients in the T− group, compared with 50% of the 4 patients in the T+/− group and 10.1% of the 79 patients in the T+ group (p less than 0.001). There were no significant differences in TIMI flow grade among the groups in patients with nonanterior STEMIs (p = 0.985). In conclusion, T− in the leads with maximal ST-segment elevation on the presenting electrocardiogram was associated with higher prevalence of patency of the infarct-related artery before intervention (64.3%), especially in patients with anterior STEMIs (100%).

I looked at the example ECGs provided in the full text of this paper. Distinguishing complete T wave inversion from biphasic T waves when marked ST elevation is present is tricky.

Saturday, September 06, 2014

Thiazide induced hyponatremia

This review refers to it as a silent epidemic, under reported in clinical trials yet well known in the real clinical world.

The paper is a bit dated, and at the time it was published the use of desmopressin to help deal with over rapid correction had not been established.

Though not covered in the review it is worth mention that mere correction of the hypokalemia (which nearly always accompanies thiazide induced hyponatremia) can result in an overly rapid rise in the serum sodium.

Friday, September 05, 2014

Combining a clinical risk score with D dimer testing to rule out aortic dissection

From the International Journal of Cardiology:

•We evaluated ADD risk score plus D-dimer for the rule-out of aortic dissection.
•D-dimer less than 500 ng/mL had a sensitivity of 100% in patients with ADD risk score 0.
•D-dimer less than 500 ng/mL had a sensitivity of 98.7% in patients with ADD risk score less than or equal to 1.
•ADD risk score 0/less than or equal to1 plus D-dimer less than 500 ng/mL accurately ruled-out aortic dissection.

More on the ADD score here.

I first suggested combining the tools here.

Tuesday, September 02, 2014

Time to antibiotic initiation and mortality in severe sepsis and septic shock

Here's even more evidence from the Surviving Sepsis Campaign:

A total of 17,990 patients received antibiotics after sepsis identification and were included in the analysis. In-hospital mortality was 29.7% for the cohort as a whole. There was a statically significant increase in the probability of death associated with the number of hours of delay for first antibiotic administration. Hospital mortality adjusted for severity (sepsis severity score), ICU admission source (emergency department, ward, vs ICU), and geographic region increased steadily after 1 hour of time to antibiotic administration. Results were similar in patients with severe sepsis and septic shock, regardless of the number of organ failure.

The results of the analysis of this large population of patients with severe sepsis and septic shock demonstrate that delay in first antibiotic administration was associated with increased in-hospital mortality. In addition, there was a linear increase in the risk of mortality for each hour delay in antibiotic administration. These results underscore the importance of early identification and treatment of septic patients in the hospital setting.

As the blog author at Intensive care medicine worth knowing pointed out, restrictive strategies for initial antibiotic decisions are losing their place in antibiotic stewardship. De-escalation is where it's at.