Better Than You Think—Appropriate Use of Implantable Cardioverter-Defibrillators at a Single Academic Center: A Retrospective Review

Background: Implantable cardioverter-defibrillators (ICDs) can be life-saving devices, although they are expensive and may cause complications. In 2013, several professional societies published joint appropriate use criteria (AUC) assessing indications for ICD implantation. Data evaluating the clinical application of AUC are limited. Previous registry-based studies estimated that 22.5% of primary prevention ICD implantations were “non-evidence-based” implantations. On the basis of AUC, we aimed to determine the prevalence of “rarely appropriate” ICD implantation at our institution for comparison with previous estimates.Methods: We reviewed 286 patients who underwent ICD implantation between 2013 and 2016. Appropriateness of each ICD implantation was assessed by independent review and rated on the basis of AUC.Results: Of 286 ICD implantations, two independent reviewers found that 89.5% and 89.2%, respectively, were appropriate, 5.6% and 7.3% may be appropriate, and 1.8% and 2.1% were rarely appropriate. No AUC indication was found for 3.5% and 3.4% of ICD implantations, respectively. Secondary prevention ICD implantations were more likely rarely appropriate (2.6% vs. 1.2% and 3.6% vs. 1.1%) or unrated (6.0% vs. 1.2% and 2.7% vs. 0.6%). The reviewers found 3.5% and 3.4% of ICD implantations, respectively, were non-evidence-based implantations. The difference in rates between reviewers was not statistically significant.Conclusion: Compared with prior reports, our prevalence of rarely appropriate ICD implantation was very low. The high appropriate use rate could be explained by the fact that AUC are based on current clinical practice. The AUC could benefit from additional secondary prevention indications. Most importantly, clinical judgement and individualized care should determine which patients receive ICDs irrespective of guidelines or criteria.

Use of Cardiac Troponin Testing in the Outpatient Setting

OBJECTIVES

Cardiac troponin (cTn) measurement is useful for diagnosing myocardial infarction (MI), particularly in the inpatient setting. A growing body of literature suggests that cTn may be useful for evaluating chronic conditions in the outpatient environment; however, little is known regarding cTn ordering patterns in this setting. We sought to investigate patterns of care and outcomes for patients evaluated with cTn in the outpatient setting. We hypothesized that a majority of outpatient cTn orders would be for the purpose of diagnosing possible MI.

METHODS

We analyzed 228 patients who had outpatient orders for standard-sensitivity troponin T assays placed at our institution between January 1, 2013 and December 18, 2015. Data were divided into two cohorts based on the intended utility of cTn measurement: orders placed to evaluate for possible MI versus orders placed for some other purpose.

RESULTS

Of the 228 patients, 161 were evaluated for possible MI and 67 for other reasons. Risk factors (hypertension P = 0.32, diabetes mellitus P = 0.41, coronary disease P = 0.38, heart failure P = 0.098, and chronic kidney disease P = 0.70) were similar between the cohorts. In the suspected MI cohort, an electrocardiogram was obtained in only 77% of patients, and only 13.1% were sent to the emergency department (ED) for further evaluation. Within the suspected MI cohort, 10.5% (n = 17) had elevated cTn and the majority of these patients (n = 10) were not sent to the ED.

CONCLUSIONS

The majority of outpatient cTn orders were intended to evaluate for MI, although electrocardiograms were frequently not ordered and few patients were sent for further ED evaluation. Providers should be encouraged to use cTn testing in a manner that minimizes the potential risk to patients with possible MI.

Taming glutamate excitotoxicity: strategic pathway modulation for neuroprotection

Much work has been carried out in recent years showing that elevated glutamate levels in the extracellular environment of the central nervous system play a pivotal role in neurodegeneration in acute CNS injuries. With the elucidation of the mechanism governing glutamate excitotoxicity, researchers are devising therapeutic strategies to target different parts of the pathway which begins with glutamate accumulation and ultimately results in neuronal cell death. In this article, we review some of the major classes of agents that are currently being investigated and highlight some of the key studies for each. Glutamate scavenging is a relatively new approach that directly decreases glutamate levels in the brain, thus preventing excitotoxicity. Nitric oxide inhibitors and free radical scavengers are more well-studied strategies that continue to yield promising results.