1. Diagnostic and therapeutic value of coronary angiography and CT-scan after eCPR – a single center registry study
Viviane Zotzmann, Tobias Wengenmayer , Daniel Dürschmied, Christoph Bode, Dawid Staudacher Heart Center Freiburg University ● Department of Cardiology and Angiology I ● Freiburg i.Br. ● Germany
Introduction:
Implantation of a venoarterial extracorporeal membrane oxygenation (ECMO) in patients with ongoing cardiopulmonary resuscitation without return of spontaneous circulation (ROSC) is coined eCPR and aims for stabilization of macro-hemodynamics. Further diagnostic work up is needed in order to diagnose and treat the cause for collapse. In case of ST-elevation after ROSC , an immediate coronary angiography is recommended by current guidelines. In addition, the PROCAT registry suggested a survival benefit with early coronary angiography in patients without ST-elevation.
Patients after eCPR however compromise a heterogeneous population with potentially different or more severe underlying pathologies when compared to patients with ROSC. If eCPR patients should undergo a similar diagnostic workup as patients with ROSC or if eCPR patients more frequently present with rare causes for cardiac arrest (pneumothorax or cardiac tamponade) and therefore need other diagnostic tools is unclear.
Aim of the study:
Aim of this study is the evaluation of the diagnostic and therapeutic value of coronary angiography and CT-scan in patients after eCPR.
Methods: Data presented derives from a single center retrospective registry analysis. All patients after eCPR treated at a single tertiary referral hospital between December 2010 and November 2015 were included. Patients after in hospital as well as out of hospital cardiac arrest were considered. As diagnosis for eCPR the final diagnosis is reported and not the presumed one at time of implantation
Diagnostic after eCPR
After implantation of the ECMO (and initial bed sinde diagnistic including physical examination, ECG and ultrasound studies and arterial blood gases) patients were routed for coronary angiography, body ct scan or both depending on the clinical judgement of the responsable intensivist.
Figure 1: patient work-up after eCPR.
p.=patients
CT Scan
CT-scan was performed at similar rates in both groups (65.4% vs 50.7%, p=.14).
Figure 3: CT after eCPR
Pathologies deemed responsible for collapse however were found more often in patients with non-shockable rhythm (23.5% vs. 0%, p<.01). CT-Scan yielded findings relevant to the further treatment frequently in both groups (92.2% vs 91.6%, p=1). Cause for collapse could be detected by CT-scan at significantly lower rates when compared to coronary angiography in both groups (23.5% vs.71.0% and 0% vs. 83.3%, both p<.01).
Study population:
A total of 123 patients were evaluated (age 59.5 ± 15.3 years, low-flow time 59.0 ± 28.2 min, survival 11.4 %). 52 patients presented without STEMI or non-shockable rhythm (age 63.8 ± 16.1 years, low-flow duration 51.0 ± 23.1 min, survival 15.4 %) while 71 patients presented with either a shockable rhythm or ST-elevation (age 56.3 ± 14.0 years, low-flow duration 64.8 ± 30.2 min, survival 8.5 % p<.01, <.01 and .03, respectively). For detailed information see table 1
Table 1: Patient characteristics
Patients characteristics are given in: number of patients [percent of all patients] or as mean ± standard deviation. Statistics were calculated using t-test or Chi²-test as applicable. IHCA=in hospital cardiac arrest, OHCA=out of hospital cardiac arrest,
Coronary angiography:
Angiography was performed significantly less frequent in patients with non-shockable rhythm (59.6% vs. 93.0% p<.01), see Figure 1a.
Figure 2: Coronary angiography after eCPR
A lesion deemed responsible for collapse however was found at similar rates in both groups (71.0% with non-shockable rhythm vs. 83.3% with ST-elevation or shockable rhythm, p=.18).
Limitations
This study represent a retrospective analysis of a heterogenious patient collective. Decision to perform coronary angiography, CT scan or both were driven by clinical judgement of the responsable intensivist. Diagnostic yeald of unselected eCPR patients for both diagnostic tools is lokely lower than suggested by data presented here.
Conclusion
After eCPR, coronary angiography revealed the cause for collapse significantly more often when compared to CT-scan disregarding initial rhythm or presence of ST-elevation. Considering the potential therapeutic option, a coronary angiography first approach might therefore be preferable. A routine CT-scan however might be reasonable in all patients since significant findings are frequent.