Door-to-balloon time and mortality in patients with ST-elevation myocardial infarction undergoing primary angioplasty

The evidence are not conclusive that a small incremental increase in door-to-balloon (D2B) time leads to a significant increase in death of ST-elevation myocardial infarction (STEMI) patients. In a previous study, we described a quality improvement intervention that reduced D2B time in 333 patients with STEMI. The aim of the current study was to compare mortality rates of the patients, before and after the intervention.

We examined the survival of 133 consecutive patients with STEMI treated prior to an intervention to decrease D2B time and 200 treated after the intervention. The mortality rate was the same before and after the quality intervention. The median D2B time for the entire cohort was 55 min. The number of patients with D2B time >55 min prior to the intervention was 82/133 (61%) and after the intervention 74/200 (37%) P < 0.00001. Thirty-day mortality among the patients with D2B time ≤55 min was 5/178 (2.8%) and among those with D2B time >55 min was 15/155 (9.7%), P < 0.008. The hazard ratio for 30-day mortality when the D2B time was >55 min was 3.7 (1.3–10.4).

Mortality and non-fatal complications did not differ significantly between STEMI patients before and after a quality improvement intervention. However, the number of patients treated within 55 min from arrival was significantly higher after the intervention; and coronary intervention within this time was associated with a lower death rate.