Time to treatment and ST-segment resolution in high-risk patients with acute myocardial infarction transferred from community hospitals for coronary angioplasty after pharmacological treatment

Abstract

Objective 

To evaluate the impact of symptom-onset-to-balloon delay on ST-segment resolution (STR) in patients with acute myocardial infarction transferred from community hospitals for angioplasty after pharmacological treatment. The study design was prospective, single centre registry.

Methods 

Between October 2000 and December 2003, 330 consecutive patients aged ≤75 years with high-risk myocardial infarction were considered; 193 patients underwent primary percutaneous coronary intervention (PCI) (group P), whereas 137 patients were given pharmacological therapy and were immediately transferred to the hospital with PCI facilities (group F).

Results 

Compared with group P, group F showed a longer time to treatment (253 ± 136 vs. 195 ± 141 min; P < 0.0001) and a higher percentage of Thrombolysis In Myocardial Infarction flow grade 2–3 at pre-PCI angiography (107 [78.1%] vs. 48 [24.8%]; P < 0.0001). The rate of STR ≥70% was similar in groups P and F (121 [62.7%] vs. 94 [68.6%]; P = 0.41). Even after accounting for baseline variables, STR <70% was not significantly related to the transfer strategy (adjusted hazard ratio 0.94, 95% confidence interval 0.94–1.77; P = 0.8). Patients with incomplete STR showed a higher six-month mortality compared with patients with complete STR (10 [8.85%] vs. 6 [2.76%]; P = 0.027).

Conclusions 

The STR index predicts survival in patients with ST-elevation myocardial infarction treated with angioplasty either directly or after pharmacological treatment and hospital transfer. Pharmacological facilitation seems to be able to counterbalance the negative consequences of the transfer-related time delay on myocardial reperfusion as evaluated by the STR index.