And Here’s Why CTCA Is Useless

In the Emergency Department, that is, at least.

A few years ago, there were several major studies evaluating the safety of a CT coronary angiogram-based study for the evaluation of chest pain in the Emergency Department. These studies consistently found the CTCA is sensitive for coronary artery plaque – and, thus, patients with troponin-negative chest pain syndromes and clear coronary arteries could be discharged from the ED.

The constant challenge, however, has been specificity – not only with respect to whether the CT can accurately detect stenoses, but the clinical relevance of the stenoses. Non-obstructive, moderate, and high-grade stenoses detected on CTCA all trigger further evaluation – either non-invasive or invasive, with subsequent interventions of uncertain clinical value.

This small propensity-matched study from a cohort of 25,251 patients undergoing CTCA picked out 234 pairs of patients, matching those who had an acute coronary syndrome during follow-up with those who did not. And, yes, those with ≥50% or ≥70% stenosis were more likely to suffer an ACS, but not my much. The vast majority – 62% – of those with an ACS in follow-up had non-obstructive coronary disease. Indeed, just over half of patients with an ACS even had their culprit lesion identified on the initial CTCA. The degree of stenosis was mildly predictive of future ACS, but plaque burden between those who suffered an event and those who did not was similar. The most predictive feature, however, was composition of non-obstructive plaque, including fibrofatty features and necrotic core.

This is why CTCA is unhelpful in the Emergency Department. It does, yes, accurately detect patients without coronary disease – but this target “low-risk” population already has such a low pretest likelihood of poor outcome the added value is nil. Then, the “true positives” from these studies – stenoses and interventions – are not equivalent to ACS prevented.

Friends don’t let friends do CTCA in the ED – it doesn’t add value or prevent adverse outcomes.

“Coronary Atherosclerotic Precursors of Acute Coronary Syndromes”
http://www.onlinejacc.org/content/71/22/2511

Roc Vs. Sux, Settled

Short answer: rocuronium, just because.

Better answer: it really doesn’t matter, please stop devoting neurons and pages to the debate.

This is a result from the National Emergency Airway Registry, a prospective database of ED airway procedures. In the sample analyzed, there were 4,275 intubations, roughly split evenly between succinylcholine and rocuronium. Generally, the cohorts were well-matched on baseline and operator characteristics.

The winner, and still champion is: they tied. First-pass success, a surrogate for effectiveness as a paralytic, was effectively identical between agents at ~87%. Adverse events, patient-oriented outcomes relating to procedural harms, were likewise effectively identical at ~15%.

This is not a randomized controlled trial, so it’s not possible to fully exclude a selection bias in which patient-level characteristics influenced the choice of agent. However, these are consistent with a Bayesian pretest likelihood of clinical equivalency. Frankly, I don’t think the cost of an RCT adds much value over these observational data sets, and any dogmatic attachment to one agent over another should be expunged. Certain clinical situations may make one agent more preferable than another, but, generally speaking, they are both excellent and effective tools.

“Emergency Department Intubation Success With Succinylcholine Versus Rocuronium: A National Emergency Airway Registry Study”
https://www.annemergmed.com/article/S0196-0644(18)30318-4/fulltext

Dialysis Purgatory

This little article is not terribly generalizable and the results are eminently predictable – but this barbaric practice was my daily routine a couple years ago while working in Houston.

To received routinely scheduled dialysis, someone must, of course, pay for it. For those U.S. citizens without the means to pay, various federal mechanisms provide coverage. For non-U.S. citizens in this country without the means to pay, there is no external payor source – unless “necessary for the treatment of an emergency medical condition.” Therefore, many facilities simply restrict dialysis to non-citizen patients in extremis.

As you might expect, this is bad and bad for you. This retrospective cohort study follows 5-year survival and resource utilization, comparing those at hospitals where non-U.S. citizens could be eligible for scheduled dialysis with those at facilities where only emergency dialysis was available. The sample sizes are small – 169 in the “emergency-only” cohort and 42 in “standard” – but at 5 year follow-up, over half the “emergency-only” cohort had died, as compared with about 10% of the standard hemodialysis. Various statistical analyses and propensity matching further quantify the exact excess hazard of emergency dialysis.

Patients receiving emergency dialysis received, obviously, fewer sessions per month – 6.2 instead of 10.3. However, these savings are potentially offset by a ten-fold increase in acute care days, probably associated with those episodes of emergency dialysis. In the most morbid sense, unfortunately, total cost-savings probably favor the emergency dialysis cohort owing to the greatly increased mortality.

There are uncertainties and holes in these sorts of retrospective studies, particularly in a cohort whose deaths are potentially not documented in our national registries. The face validity for the overall findings is strong, however, even if the specific numbers are not reliable.

Regardless, just as a manner of respecting basic human decency, it is simple cruelty to layer this additional suffering onto the already miserable state of being dialysis-dependent. All feasible efforts should be made to provide access to regular dialysis, considering the burden on the health system infrastructure is likely similar.

“Association of Emergency-Only vs Standard Hemodialysis With Mortality and Health Care Use Among Undocumented Immigrants With End-stage Renal Disease”
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2665387