Objectives To determine whether resuscitated cardiac arrest (CA) complicating ST elevation myocardial infarction (STEMI) impacts outcome, particularly in patients surviving to discharge.

Background Resuscitated CA complicating STEMI is associated with increased inpatient mortality. The impact on later prognosis is unclear.

Methods We analysed data from the UK Myocardial Ischaemia National Audit Project for STEMI patients admitted during January 2008–March 2010. We used survival analyses to assess the independent impact of resuscitated CA during the index episode on inhospital, 30 days, 1 year and medium term all-cause mortality.

Results Of 48 749 STEMI patients, 5308 (10.9%) were recorded as having a CA. Of these, 1557 (29.3%) died on the day of CA. In survivors, after covariate adjustment, resuscitated CA was associated with increased risk of death during the index admission (HR 4.05 (3.69 to 4.45) p<0.001). In patients surviving to discharge, a history of resuscitated CA was associated with increased risk of death to 30 days (HR 1.53 (1.18 to 2.00), p<0.001). However, beyond 30 days, resuscitated CA was not associated with increased mortality risk (1-year HR 0.95 (0.79 to 1.14, p=0.596); 3.5 years HR 0.90 (0.78 to 1.04), p=0.144). The influence of resuscitated CA on inhospital or 30-day mortality was similar whether CA occurred before or after hospital admission. Where the resuscitated CA rhythm was asystole, inhospital mortality was higher compared with ventricular arrhythmia (p<0.001) or pulseless electrical activity (p=0.011). Late resuscitated CA (occurring after the day of index STEMI) was associated with higher 30-day postdischarge mortality compared with early resuscitated CA (p=0.023).

Conclusions STEMI complicated by resuscitated CA merits careful monitoring in the early period postevent. In contemporary practice, there is no impact of resuscitated CA on longer-term prognosis.