An early invasive strategy of coronary angiography and percutaneous coronary intervention (PCI) is associated with better outcomes at discharge for patients admitted for out-of-hospital cardiac arrest (OHCA) without ST-segment elevation, a Parisian registry study suggested.
This population with an initially successfully resuscitation was more likely to have favorable neurological outcomes following emergent PCI than with no emergent PCI (43% versus 33%, P=0.02), an advantage that persisted after multivariable adjustment (odds ratio [OR] 1.80, 95% confidence interval [CI] 1.09-2.97)
Other predictors of good outcomes on discharge were resuscitation lasting less than 20 minutes (OR 3.15, 95% CI 1.94-5.10) and presence of an initial shockable rhythm (OR 3.40, 95% CI 1.95-5.91), Florence Dumas, MD, PhD, of Paris Descartes University, and colleagues, reported in JACC: Cardiovascular Interventions.
Epinephrine dosage greater than 2 mg during resuscitation was, on the contrary, linked to worse outcomes (OR 0.27, 95% CI 0.16-0.46).
“In centers where a systematic invasive approach at admission cannot be performed, patients could be triaged for emergent angiogram using these factors,” the authors wrote.
“These findings support the use of an invasive strategy in these patients, particularly in those resuscitated from a shockable rhythm,” they concluded. “An immediate invasive strategy routinely applied in a large cohort is associated with a clinical benefit regarding outcome.”
In accompanying editorial, Joaquin E. Cigarroa, MD, of Oregon Health Sciences University in Portland, pointed to lessons to be learned from the French system.
“Unlike many cities within the United States, the structured approach in Paris includes a central command center, an emergency field team including a physician, and immediate coronary angiography in patients with OHCA (without extra-cardiac etiologies) with return of spontaneous circulation, regardless of the electrocardiography [ECG] findings.”
“Clearly, systems of care in the United States should learn from the Parisian OHCA structure and standardize care so patients can benefit from the rapid initiation of cardiopulmonary resusciation, appropriate use of an automated external defibrillator, and emergency medical services teams designed to implement care and transport patients to dedicated centers for OHCA.”
The PROCAT II registry included 958 people admitted after resuscitation from an OHCA without an obvious extra-cardiac cause between 2004 and 2013, among whom 73% had no evidence of ST-segment elevation.
Participants scoring 1 or 2 on the Cerebral Performance Category scale on hospital discharge were deemed to have favorable outcomes.
Having an initial shockable rhythm was the only independent predictor for successful PCI (OR 2.83, 95% CI 1.84-4.36). Among patients, 29% had coronary lesions that required PCI.
On subgroup analysis, men over age 50 with an initial shockable rhythm seemed to benefit the most from ad hoc PCI, with an especially high rate of good outcomes (48.1%).
“The present study is obviously limited by its non-randomized and retrospective design, precluding any conclusion regarding a causal relationship,” the authors warned.
Cigarroa highlighted the potential confounders inherent in how the authors were able to know a culprit lesion when they saw one, given “the absence of objective findings of ischemia, infarction, or new regional wall motion abnormalities.”
“Was a ‘culprit lesion’ a true cause for OHCA, an innocent bystander, or simply a marker of a more survivable etiology of OHCA regardless of whether PCI was undertaken? Did interventionalists incorporate unmeasured factors indicating clinical stability and survivability into their decision to proceed to PCI?”
In fact, “coronary physiology was not assessed, and ECG findings consistent with ischemia were not reported as a factor in determining whether to proceed with PCI. Markers of clinical stability at the time of cardiac catheterization were not incorporated into the analysis,” he wrote.
Nevertheless, he added, “although the data today for routine immediate coronary angiography in all patients without evidence of acute coronary syndrome is relatively weak, our ability to identify the patients without ST segment elevation who would benefit from early angiography and PCI is extremely difficult.”
“I believe that we can learn from the systematic approach that the PROCAT investigators have utilized in an effort to improve the evaluation and care our patients receive,” the editorialist concluded.
Dumas and Cigarroa declared no relevant conflicts of interest.
JACC: Cardiovascular Interventions
Dumas F, et al "Emergency PCI in post-cardiac arrest patients without ST-segment elevation pattern: insights from the PROCAT II registry" JACC Cardiovasc Interv 2016; DOI: 10.1016/j.jcin.2016.02.001.
JACC: Cardiovascular Interventions
Cigarroa JE "Out-of-hospital cardiac arrest survivors in patients without ST segment elevation infarction. Is routine coronary angiography reasonable?" JACC Cardiovasc Interv 2016; DOI: 10.1016/j.jcin.2011.07.004.