Prognostic significance of shockable and non-shockable cardiac arrest in ST-segment elevation myocardial infarction patients undergoing primary angioplasty

Objective To determine, in patients with ST-segment Elevation Myocardial Infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI), the prognostic weight of cardiac arrest (CA) according to the type of rhythm (shockable vs. non-shockable). Methods We prospectively enrolled 3278 consecutive STEMI patients undergoing PPCI. Multivariable Cox regression was used to establish the relation to 1-year cardiac mortality of both type of CA. In patients suffering from CA we identified predictors of both poor neurological outcome (cerebral performance categories 3–5) and cardiac mortality at 1 year. Results The incidence of CA was 7.26% (n = 238). Of these, 196 (5.98%) had an initial shockable rhythm and 42 (1.28%) a non shockable rhythm. During 1-year follow up 311(9.48%) patients died from cardiac causes. Shockable rhythm (adjusted-HR = 1.61; 95%CI 1.08–2.43, p = 0.02) and non-shockable rhythm (adjusted-HR = 3.83; 95%CI 2.36–6.22, p < 0.001) were independently associated with 1-year cardiac mortality. Among patients with CA those with shockable rhythm had a lower risk of poor neurological outcome at 1 year follow up (adjusted OR = 0.22: 95%CI; 0.08–0.55, p = 0.001). Independent predictors of 1-y cardiac mortality were: non shockable rhythm (adjusted HR = 2.6; 95%CI; 1.48–4.5, p = 0.001), crew-witnessed CA, diabetes mellitus, left ventricle ejection fraction and creatinine on admission. There was a significant interaction between type of rhythm and crew-witnessed CA (p = 0.026). Conclusions In patients with STEMI undergoing PPCI patients with both shockable and non shockable CA are at increased risk of 1-year cardiac mortality. Among patients with CA those with non shockable rhythm have an higher risk of both poor neurological outcome and cardiac mortality at 1 year.